阅读说明：本技术 反射式胆固醇液晶显示器 (Reflective cholesterol liquid crystal display ) 是由 廖奇璋 古俊纲 于 2019-12-20 设计创作，主要内容包括：一种反射式胆固醇液晶显示器包括第一显示单元。第一显示单元包括第一上透明基板、第一下基板、形成于第一上透明基板的第一上透明电极图案、形成于第一下基板的第一下透明电极图案、夹置在第一上透明电极图案与第一下透明电极图案之间的第一胆固醇液晶层、以及形成于第一上透明基板的第一光吸收层。第一胆固醇液晶层用于产生第一可见光,其包括第一波长范围。第一光吸收层用于吸收第一波长范围以外的光线,以使位在第一波长范围内的第一可见光通过第一光吸收层与第一上透明基板。如此,上述反射式胆固醇液晶显示器能减少画面发生颜色偏差的情形,改善色彩饱和度,提升影像质量。(A reflective cholesteric liquid crystal display includes a first display unit. The first display unit includes a first upper transparent substrate, a first lower substrate, a first upper transparent electrode pattern formed on the first upper transparent substrate, a first lower transparent electrode pattern formed on the first lower substrate, a first cholesteric liquid crystal layer interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern, and a first light absorbing layer formed on the first upper transparent substrate. The first cholesterol liquid crystal layer is used for generating first visible light and comprises a first wavelength range. The first light absorption layer is used for absorbing light rays outside the first wavelength range, so that first visible light in the first wavelength range passes through the first light absorption layer and the first upper transparent substrate. Therefore, the reflective cholesterol liquid crystal display can reduce the color deviation of the picture, improve the color saturation and improve the image quality.)

1. A reflective cholesteric liquid crystal display, comprising:

a first display unit comprising:

a first upper transparent substrate;

a first lower substrate;

a first upper transparent electrode pattern formed on the first upper transparent substrate;

a first lower transparent electrode pattern formed on the first lower substrate, wherein the first upper transparent electrode pattern and the first lower transparent electrode pattern face each other;

a first cholesteric liquid crystal layer interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern and generating a first visible light including a first wavelength range; and

the first light absorption layer is formed on the first upper transparent substrate and used for absorbing light rays outside the first wavelength range, so that the first visible light in the first wavelength range passes through the first light absorption layer and the first upper transparent substrate.

2. The reflective cholesteric liquid crystal display according to claim 1, wherein the first light absorption layer is formed between the first upper transparent substrate and the first upper transparent electrode pattern.

3. The reflective cholesteric liquid crystal display of claim 1, wherein the first display unit further comprises a first black pattern between the first upper transparent substrate and the first upper transparent electrode pattern.

4. The reflective cholesteric liquid crystal display according to claim 3, wherein the first light absorption layer is formed between the first upper transparent substrate and the first upper transparent electrode pattern, and the first black pattern has a plurality of first cells, and the first light absorption layer is filled in the first cells.

5. The reflective cholesteric liquid crystal display of claim 1, wherein the first display unit further comprises a plurality of first spacers interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern.

6. The reflective cholesteric liquid crystal display of claim 1, further comprising a second display unit and a first optically transparent adhesive layer, wherein the first optically transparent adhesive layer is adhered between the first display unit and the second display unit, and the second display unit comprises:

a second upper transparent substrate;

a second lower transparent substrate, wherein the first optical transparent adhesive layer is adhered between the first upper transparent substrate and the second lower transparent substrate;

a second upper transparent electrode pattern formed on the second upper transparent substrate;

a second lower transparent electrode pattern formed on the second lower transparent substrate, wherein the second upper transparent electrode pattern and the second lower transparent electrode pattern face each other; and

a second cholesteric liquid crystal layer sandwiched between the second upper transparent electrode pattern and the second lower transparent electrode pattern and generating a second visible light, wherein the second visible light includes a second wavelength range, and the first wavelength range is different from the second wavelength range.

7. The reflective cholesteric liquid crystal display according to claim 6, wherein the second display unit further comprises a second light absorption layer formed on the second upper transparent substrate and absorbing light outside of both the first wavelength range and the second wavelength range such that the first visible light in the first wavelength range and the second visible light in the second wavelength range both pass through the second light absorption layer and the second upper transparent substrate.

8. The reflective cholesteric liquid crystal display according to claim 7, wherein the second light absorption layer is formed between the second upper transparent substrate and the second upper transparent electrode pattern.

9. The reflective cholesteric liquid crystal display according to claim 8, wherein the first display unit further comprises a plurality of first spacers interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern;

the second display unit further comprises a plurality of second spacers, and the second spacers are sandwiched between the second upper transparent electrode pattern and the second lower transparent electrode pattern.

10. The reflective cholesteric liquid crystal display of claim 7, wherein the first display unit further comprises a first black pattern between the first upper transparent substrate and the first upper transparent electrode pattern;

the second display unit also comprises a second black pattern which is positioned between the second upper transparent substrate and the second upper transparent electrode pattern.

11. The reflective cholesteric liquid crystal display according to claim 10, wherein the first light absorption layer is formed between the first upper transparent substrate and the first upper transparent electrode pattern, and the second light absorption layer is formed between the second upper transparent substrate and the second upper transparent electrode pattern;

the first black pattern has a plurality of first grids, the first light absorption layer is filled in the first grids, the second black pattern has a plurality of second grids, and the second light absorption layer is filled in the second grids.

12. The reflective cholesteric liquid crystal display of claim 7, further comprising a third display unit and a second optically transparent adhesive layer adhered between the second display unit and the third display unit.

13. The reflective cholesteric liquid crystal display according to claim 6, wherein the first display unit further comprises a plurality of first spacers interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern;

the second display unit further comprises a plurality of second spacers, and the second spacers are sandwiched between the second upper transparent electrode pattern and the second lower transparent electrode pattern.

14. The reflective cholesteric liquid crystal display of claim 6, further comprising:

a second optical transparent adhesive layer;

a third display unit comprising:

a third upper transparent substrate;

a third lower transparent substrate, wherein the second optical transparent adhesive layer is adhered between the second upper transparent substrate and the third lower transparent substrate;

a third upper transparent electrode pattern formed on the third upper transparent substrate;

a third lower transparent electrode pattern formed on the third lower transparent substrate, wherein the third upper transparent electrode pattern and the third lower transparent electrode pattern face each other; and

a third cholesteric liquid crystal layer sandwiched between the third upper transparent electrode pattern and the third lower transparent electrode pattern; and

and the second light absorption layer is formed on the third lower transparent substrate and is used for absorbing light rays outside the first wavelength range and the second wavelength range, so that the first visible light in the first wavelength range and the second visible light in the second wavelength range both pass through the second light absorption layer and the third upper transparent substrate, and the first wavelength range is different from the second wavelength range.

15. The reflective cholesteric liquid crystal display according to claim 14, wherein the second light absorption layer is formed between the third lower transparent substrate and the third lower transparent electrode pattern.

16. The reflective cholesteric liquid crystal display of claim 14, wherein the first display unit further comprises a first black pattern between the first upper transparent substrate and the first upper transparent electrode pattern;

the second display unit also comprises a second black pattern which is positioned between the second upper transparent substrate and the second upper transparent electrode pattern;

the third display unit further comprises a third black pattern, and the third black pattern is located between the third upper transparent substrate and the third upper transparent electrode pattern.

17. The reflective cholesteric liquid crystal display according to claim 16, wherein the first light absorption layer is formed between the first upper transparent substrate and the first upper transparent electrode pattern, and the second light absorption layer is formed between the third lower transparent substrate and the third lower transparent electrode pattern;

the first black pattern has a plurality of first grids, and the first light absorption layer is filled in the first grids.

18. The reflective cholesteric liquid crystal display of claim 14, wherein the first display unit further comprises a plurality of first spacers interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern;

the second display unit further comprises a plurality of second spacers, and the second spacers are sandwiched between the second upper transparent electrode pattern and the second lower transparent electrode pattern; and

the third display unit further comprises a plurality of third spacers, and the third spacers are sandwiched between the third upper transparent electrode pattern and the third lower transparent electrode pattern.

19. A reflective cholesteric liquid crystal display, comprising:

a first display unit comprising:

a first upper transparent substrate;

a first lower substrate

A first upper transparent electrode pattern formed on the first upper transparent substrate;

a first lower transparent electrode pattern formed on the first lower substrate, wherein the first upper transparent electrode pattern and the first lower transparent electrode pattern face each other;

a first cholesteric liquid crystal layer interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern and generating a first visible light including a first wavelength range;

a first optical transparent adhesive layer;

a second display unit includes:

a second upper transparent substrate;

a second lower transparent substrate, wherein the first optical transparent adhesive layer is adhered between the first upper transparent substrate and the second lower transparent substrate;

a second upper transparent electrode pattern formed on the second upper transparent substrate;

a second lower transparent electrode pattern formed on the second lower transparent substrate, wherein the second upper transparent electrode pattern and the second lower transparent electrode pattern face each other;

a second cholesteric liquid crystal layer interposed between the second upper transparent electrode pattern and the second lower transparent electrode pattern and generating a second visible light, wherein the second visible light includes a second wavelength range, and the first wavelength range is different from the second wavelength range; and

and the first light absorption layer is formed on the second lower transparent substrate and used for absorbing light rays outside the first wavelength range so as to enable the first visible light in the first wavelength range to pass through the first light absorption layer and the second upper transparent substrate.

20. The reflective cholesteric liquid crystal display according to claim 19, wherein the first light absorption layer is formed between the second lower transparent substrate and the second lower transparent electrode pattern.

21. The reflective cholesteric liquid crystal display of claim 19, wherein the first display unit further comprises a first black pattern formed between the first upper transparent substrate and the first upper transparent electrode pattern.

22. The reflective cholesteric liquid crystal display of claim 21, wherein the second display unit further comprises a second black pattern formed between the second upper transparent substrate and the second upper transparent electrode pattern.

23. The reflective cholesteric liquid crystal display of claim 19, wherein the first display unit further comprises a plurality of first spacers interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern;

the second display unit further comprises a plurality of second spacers, and the second spacers are sandwiched between the second upper transparent electrode pattern and the second lower transparent electrode pattern.

24. The reflective cholesteric liquid crystal display of claim 19, wherein the second display unit further comprises:

a second light absorption layer formed between the second upper transparent substrate and the second upper transparent electrode pattern and used for absorbing light outside the first wavelength range and the second wavelength range, so that the first visible light in the first wavelength range and the second visible light in the second wavelength range both pass through the second light absorption layer and the second upper transparent substrate, and the first wavelength range is different from the second wavelength range.

25. The reflective cholesteric liquid crystal display of claim 24, further comprising a third display unit and a second optically transparent adhesive layer, wherein the second optically transparent adhesive layer is adhered between the second display unit and the third display unit.

26. The reflective cholesteric liquid crystal display of claim 19, further comprising a third display unit and a second optically transparent adhesive layer, wherein the second optically transparent adhesive layer is adhered between the second display unit and the third display unit, and the third display unit comprises:

a third upper transparent substrate;

a third lower transparent substrate, wherein the second optical transparent adhesive layer is adhered between the second upper transparent substrate and the third lower transparent substrate;

a third upper transparent electrode pattern formed on the third upper transparent substrate;

a third lower transparent electrode pattern formed on the third lower transparent substrate, wherein the third upper transparent electrode pattern and the third lower transparent electrode pattern face each other;

a third cholesteric liquid crystal layer sandwiched between the third upper transparent electrode pattern and the third lower transparent electrode pattern; and

a second light absorption layer formed between the third lower transparent substrate and the third lower transparent electrode pattern and used for absorbing light outside the first wavelength range and the second wavelength range, so that the first visible light in the first wavelength range and the second visible light in the second wavelength range both pass through the second light absorption layer and the third upper transparent substrate, and the first wavelength range is different from the second wavelength range.

27. The reflective cholesteric liquid crystal display of claim 26, wherein the first display unit further comprises a first black pattern formed between the first upper transparent substrate and the first upper transparent electrode pattern;

the second display unit further comprises a second black pattern formed between the second upper transparent substrate and the second upper transparent electrode pattern;

the third display unit further includes a third black pattern formed between the third upper transparent substrate and the third upper transparent electrode pattern.

28. The reflective cholesteric liquid crystal display of claim 26, wherein the first display unit further comprises a plurality of first spacers interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern;

the second display unit further comprises a plurality of second spacers, and the second spacers are sandwiched between the second upper transparent electrode pattern and the second lower transparent electrode pattern; and

the third display unit further comprises a plurality of third spacers, and the third spacers are sandwiched between the third upper transparent electrode pattern and the third lower transparent electrode pattern.

Technical Field

The present invention relates to a display, and more particularly, to a reflective cholesteric liquid crystal display.

Background

The present display technology develops a reflective Cholesteric Liquid Crystal display, which includes Cholesteric Liquid Crystal (Cholesteric Liquid Crystal) molecular arrangement having two stable states, namely a Focal Conic State (Focal Conic State) and a Planar State (Planar State), so that the Cholesteric Liquid Crystal has a bistable characteristic, i.e., the Cholesteric Liquid Crystal can maintain the original Liquid Crystal molecular arrangement State without external energy. When a voltage is applied, the arrangement state of the liquid crystal molecules can be controlled to be switched between two stable states, namely a focal conic arrangement state and a planar arrangement state. As mentioned above, when the cholesteric liquid crystal is in a planar arrangement state, light with a specific wavelength is reflected; on the contrary, when the cholesteric liquid crystal is in a focal conic arrangement state, light is transmitted. Therefore, the cholesterol liquid crystal can be controlled to be transmitted by light or reflect light with specific wavelength by using the voltage applied to the cholesterol liquid crystal.

The distance that the cholesteric liquid crystal molecules rotate one turn (360O) is called the helical Pitch (P). The wavelength (λ) and the width (Δ λ) of the cholesteric liquid crystal are calculated by the following formula (1), wherein ne is the Refractive Index (also called Extraordinary Refractive Index) of the cholesteric liquid crystal parallel to the optical axis; no is the Refractive Index of the cholesteric liquid crystal perpendicular to the optical axis (also called Ordinary Refractive Index); p is the pitch of the cholesteric liquid crystal.

Therefore, adjusting the pitch of the cholesteric liquid crystal can change the wavelength of light reflected by the cholesteric liquid crystal, and further the cholesteric liquid crystal can reflect light of a specific color, for example: blue, green or red light. Thus, the reflective cholesteric liquid crystal display can display images composed of a plurality of colors.

Referring to fig. 1, when a light ray R10 is incident on a reflective cholesteric liquid crystal display 100 at an angle θ, a cholesteric liquid crystal 101 in a planar arrangement state can reflect a light ray R11 with a specific wavelength within a light ray R10. The wavelength of light ray R11 will be proportional to the sine of the angle theta (i.e., sin theta) according to Bragg's Law. In other words, the smaller the angle θ, the closer the light ray R10 is to the surface of the reflective cholesteric liquid crystal display 100 and the incident light ray R10 enters the cholesteric liquid crystal 101, the shorter the wavelength of the light ray R11 reflected by the cholesteric liquid crystal 101 is, which causes the color deviation of the reflected light R11, resulting in the degradation of the image quality of the reflective cholesteric liquid crystal display 100.

Disclosure of Invention

The invention provides a reflective cholesterol liquid crystal display, which comprises a light absorption layer capable of absorbing light outside a specific wavelength range so as to improve the image quality of the reflective cholesterol liquid crystal display.

The invention provides a reflective cholesterol liquid crystal display which comprises a first display unit. The first display unit includes a first upper transparent substrate, a first lower substrate, a first upper transparent electrode pattern formed on the first upper transparent substrate, a first lower transparent electrode pattern formed on the first lower substrate, a first cholesteric liquid crystal layer interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern, and a first light absorbing layer formed on the first upper transparent substrate. The first upper transparent electrode pattern and the first lower transparent electrode pattern face each other. The first cholesterol liquid crystal layer is used for generating first visible light and comprises a first wavelength range. The first light absorption layer is used for absorbing light rays outside the first wavelength range, so that first visible light in the first wavelength range passes through the first light absorption layer and the first upper transparent substrate.

The invention provides another reflective cholesterol liquid crystal display which comprises a first display unit, a second display unit and a first optical transparent adhesive layer, wherein the first optical transparent adhesive layer is adhered between the first display unit and the second display unit. The first display unit includes a first upper transparent substrate, a first lower substrate, a first upper transparent electrode pattern formed on the first upper transparent substrate, a first lower transparent electrode pattern formed on the first lower substrate, and a first cholesteric liquid crystal layer interposed between the first upper transparent electrode pattern and the first lower transparent electrode pattern. The first upper transparent electrode pattern and the first lower transparent electrode pattern face each other. The first cholesteric liquid crystal layer is used for generating first visible light, wherein the first visible light passes through the first upper transparent electrode pattern and the first upper transparent substrate and comprises a first wavelength range. The second display unit includes a second upper transparent substrate, a second lower transparent substrate, a second upper transparent electrode pattern formed on the second upper transparent substrate, a second lower transparent electrode pattern formed on the second lower transparent substrate, a second cholesteric liquid crystal layer interposed between the second upper transparent electrode pattern and the second lower transparent electrode pattern, and a first light absorbing layer formed on the second lower transparent substrate. The first optical transparent adhesive layer is adhered between the first upper transparent substrate and the second lower transparent substrate. The second upper transparent electrode pattern and the second lower transparent electrode pattern face each other. The second cholesteric liquid crystal layer is used for generating second visible light, wherein the second visible light passes through the second upper transparent electrode pattern and the second upper transparent substrate and comprises a second wavelength range, and the first wavelength range is different from the second wavelength range. The first light absorption layer is used for absorbing light rays outside the first wavelength range, so that the first visible light in the first wavelength range passes through the first light absorption layer and the second upper transparent substrate.

Based on the above, the reflective cholesteric liquid crystal display of the invention employs at least one light absorption layer (e.g., the first light absorption layer) to reduce the light emission outside a specific wavelength range (e.g., the first wavelength range), so as to improve the image quality.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the technical means of the present invention can be implemented according to the content of the description, and in order to make the above features and advantages of the present invention more clearly understood, the following features are described in detail with reference to the accompanying drawings by way of example.

Drawings

FIG. 1 is a schematic cross-sectional view of a conventional reflective cholesteric liquid crystal display.

Fig. 2A and fig. 2B are schematic cross-sectional views of a reflective cholesteric liquid crystal display according to an embodiment of the invention.

Fig. 2C is a schematic top view of the first upper transparent electrode pattern and the first lower transparent electrode pattern in fig. 2A.

Fig. 2D is a schematic top view of the first black pattern in fig. 2A.

Fig. 3A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

Fig. 3B is a schematic top view of the plurality of first spacers in fig. 3A.

Fig. 4A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

Fig. 4B is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

Fig. 5A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

FIG. 5B is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

Fig. 6A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

FIG. 6B is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

FIG. 6C is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

FIG. 6D is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

FIG. 7 is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention.

Detailed Description

In the following description, the dimensions (e.g., length, width, thickness, and depth) of elements (e.g., layers, films, substrates, regions, etc.) in the figures are exaggerated in various proportions for clarity of illustrating the features of the present disclosure. Accordingly, the description and illustrations of the embodiments below are not limited to the sizes and shapes of elements shown in the drawings, but are intended to cover deviations in sizes, shapes and both that result from actual manufacturing processes and/or tolerances. For example, the flat surfaces shown in the figures may have rough and/or non-linear features, while the acute angles shown in the figures may be rounded. Therefore, the drawings are provided for illustrative purposes only, and are not intended to accurately depict the actual shape of the components nor limit the scope of the present claims. In addition, the number of at least one element in the drawings may be significantly less than that in actual practice, so that the following description and explanation of the embodiments is not limited to the number of elements in the drawings.

Furthermore, the terms "about", "approximately" or "substantially" as used herein encompass not only the explicitly recited values and ranges of values, but also the allowable range of deviation as would be understood by one of ordinary skill in the art, wherein the range of deviation may be determined by the error in measurement, for example, due to limitations in both the measurement system and process conditions. Further, "about" can mean within one or more standard deviations of the above-recited numerical values, such as: within + -30%, + -20%, + -10% or + -5%. The terms "about," "approximately," or "substantially," as used herein, may be selected with an acceptable range of deviation or standard deviation based on optical, etching, mechanical, or other properties, and not all properties may be used alone with one standard deviation.

Fig. 2A and fig. 2B are schematic cross-sectional views of a reflective cholesteric liquid crystal display according to an embodiment of the invention. Referring to fig. 2A, the reflective cholesteric liquid crystal display 200a includes a first display unit 210a, and the first display unit 210a includes a first upper transparent substrate 211u and a first lower substrate 211 d. The first upper transparent Substrate 211u may be a Rigid Substrate (e.g., a glass plate or a poly (methyl methacrylate) (PMMA) Substrate). Alternatively, the first upper transparent Substrate 211u may be a Flexible Substrate, such as a Substrate made of Polyimide (PI) or Polyethylene Terephthalate (PET) as a main component. The first upper transparent substrate 211u may be a rigid substrate or a flexible substrate made of other materials, in addition to the materials exemplified above. Therefore, the material of the first upper transparent substrate 211u is not limited to the above-exemplified materials.

In the present embodiment, the first lower substrate 211d may be the same as the first upper transparent substrate 211 u. That is, the first lower substrate 211d may also be a transparent substrate, and may be the rigid substrate (e.g., a glass plate or a pmma (polymethyl methacrylate) substrate) or the flexible substrate (e.g., a pi (polyimide) substrate or a pet (polyethylene terephthalate) substrate). However, in other embodiments, the first lower Substrate 211d may be an Opaque Substrate (Opaque). For example, the first lower substrate 211d may be a black opaque PMMA substrate, PI substrate, or PET substrate so that the first lower substrate 211d can absorb visible light to appear black. In addition, the first upper Transparent electrode pattern 212u and the first lower Transparent electrode pattern 212d may be made of the same material, and may be both Transparent Conductive materials, such as Transparent Conductive Oxide (TCO), Conductive Polymer (Conductive Polymer), Metal Thin Film (Metal Thin Film), and the like, for example: indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), poly-3, 4-ethylenedioxythiophene (PEDOT), Copper Metal Mesh Film (Copper Metal Mesh Film), or Silver nanowires (Silver Nanowire), and the like.

The first display unit 210a further includes a first upper transparent electrode pattern 212u and a first lower transparent electrode pattern 212d, wherein the first upper transparent electrode pattern 212u is formed on the first upper transparent substrate 211u, and the first lower transparent electrode pattern 212d is formed on the first lower substrate 211 d. It should be noted that the above-mentioned "transparent electrode pattern is formed on the substrate" (i.e., the above-mentioned "first upper transparent electrode pattern 212u is formed on the first upper transparent substrate 211 u" and "first lower transparent electrode pattern 212d is formed on the first lower substrate 211 d") does not limit the transparent electrode to be in contact with the substrate.

In detail, the first upper transparent electrode pattern 212u is formed on the surface of the first upper transparent substrate 211u, but does not necessarily contact the first upper transparent substrate 211 u. Taking fig. 2A as an example, the first upper transparent electrode pattern 212U is located below the lower surface U11d of the first upper transparent substrate 211U and does not contact the lower surface U11 d. On the contrary, the first lower transparent electrode pattern 212D is formed on the surface of the first lower substrate 211D and is located on the upper surface D11u of the first lower substrate 211D, wherein the first lower transparent electrode pattern 212D contacts the upper surface D11 u. Therefore, the meaning of the present and subsequent text regarding "the transparent electrode pattern is formed on the substrate" covers the transparent electrode pattern contacting and not contacting the substrate.

Referring to fig. 2A and fig. 2C, fig. 2C is a schematic top view of the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, and fig. 2C is a schematic top view of the reflective cholesteric liquid crystal display 200a viewed along the direction Z1 in fig. 2A to illustrate the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212 d. The first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d are both patterned films (films) and may be formed by using a thin Film deposition and Photolithography (Photolithography), wherein the first upper transparent electrode pattern 212u may include a plurality of first upper conductive strips T12u arranged in parallel, and the first lower transparent electrode pattern 212d may include a plurality of first lower conductive strips T12d arranged in parallel. The first upper conductive strips T12u and the first lower conductive strips T12d are staggered with each other. Taking fig. 2C as an example, the first upper conductive strips T12u may extend along the longitudinal direction, and the first lower conductive strips T12d may extend along the transverse direction, so that the first upper conductive strips T12u and the first lower conductive strips T12d are staggered to form a mesh distribution.

The first display unit 210a further includes a first cholesteric liquid crystal layer 213 in which the first upper and lower transparent electrode patterns 212u and 212d face each other, and the first cholesteric liquid crystal layer 213 is interposed between the first upper and lower transparent electrode patterns 212u and 212 d. When a potential difference (i.e., a voltage) is generated between the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d due to the energization, a plurality of overlapping regions P21 (shown as diagonal regions in fig. 2C, wherein fig. 2C only indicates one overlapping region P21 for explanation) between the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d generate an electric field, so as to change the arrangement of liquid crystal molecules in the first cholesteric liquid crystal layer 213, such that the first cholesteric liquid crystal layer 213 can be in a focal conic arrangement state or a planar arrangement state, wherein the overlapping region P21 is substantially equivalent to a pixel of the reflective cholesteric liquid crystal display 200 a.

The first cholesterol liquid crystal layer 213 in fig. 2A is in a planar arrangement state, and the first cholesterol liquid crystal layer 213 in fig. 2B is in a focal conic arrangement state. Referring to fig. 2A, when an external light R20 is incident on the reflective cholesteric liquid crystal display 200a from the first upper transparent substrate 211u, the first cholesteric liquid crystal layer 213 in a planar arrangement receives the external light R20 and reflects the first visible light R21 in the external light R20, so that the first cholesteric liquid crystal layer 213 can generate the first visible light R21 including a specific first wavelength range. It should be noted that although the first visible light R21 includes the first wavelength range, the first visible light R21 also includes other wavelength ranges outside the first wavelength range, so the first wavelength range is not equal to the entire wavelength range of the first visible light R21.

The first visible light R21 may be light with a specific color, such as red light, green light or blue light, and the first wavelength range may be a wavelength range of a certain color, such as a wavelength range of red light between 590 nm and 740 nm, a wavelength range of green light between 500 nm and 590 nm, or a wavelength range of blue light between 415 nm and 500 nm. The first visible light R21 can pass through the first upper transparent electrode pattern 212U and the first upper transparent substrate 211U and exit from the upper surface U11U of the first upper transparent substrate 211U. At this time, when the display screen of the reflective cholesteric liquid crystal display 200a is viewed, that is, the upper surface U11U is viewed from the direction Z1, a bright state screen formed by the first visible light R21 can be seen.

The first display unit 210a further includes a first light absorption layer 214 formed on the first upper transparent substrate 211 u. The meaning of "the first light absorption layer 214 is formed on the first upper transparent substrate 211 u" covers the first light absorption layer 214 contacting and not contacting the first upper transparent substrate 211u, as in the meaning of "the transparent electrode pattern is formed on the substrate". In other words, the first light absorbing layer 214 is formed on the surface of the first upper transparent substrate 211U, such as the upper surface U11U or the lower surface U11d of the first upper transparent substrate 211U, wherein the first light absorbing layer 214 may or may not contact the first upper transparent substrate 211U. Accordingly, the first light absorption layer 214 may be formed between the first upper transparent substrate 211u and the first upper transparent electrode pattern 212u, as shown in fig. 2A and 2B. Alternatively, the first upper transparent substrate 211u may be positioned between the first upper transparent electrode pattern 212u and the first light absorption layer 214. Accordingly, fig. 2A and 2B are only for illustration and do not limit the first light absorbing layer 214 to be formed only between the first upper transparent substrate 211u and the first upper transparent electrode pattern 212 u.

The first light absorbing layer 214 may be made of photoresist or Ink, and the method of forming the first light absorbing layer 214 may include Spin Coating (Spin Coating), roll Coating (Roller Coating), or Spray Coating (Spin Coating/Ink Jet Printing), wherein the thickness 214t of the first light absorbing layer 214 may be between 0.1 micron and 100 microns. The first light absorbing layer 214 absorbs light outside the first wavelength range, so when the first visible light R21 is incident on the first light absorbing layer 214, the first visible light R21 outside the first wavelength range is absorbed by the first light absorbing layer 214, and the first visible light R21 within the first wavelength range passes through the first light absorbing layer 214. In other words, the first light absorbing layer 214 absorbs a portion of the first visible light R21 and allows other first visible light R21 to pass through.

According to bragg's law, when the external light R20 is incident on the first cholesteric liquid crystal layer 213 near the upper surface U11U of the first upper transparent substrate 211U, the wavelength of the first visible light R21 is changed to a short wavelength without the first light absorbing layer 214. In other words, if the external light R20 is incident on the reflective cholesteric liquid crystal display 200a without the first light absorption layer 214 from all directions, the first visible light R21 generated by the first cholesteric liquid crystal layer 213 includes not only the first wavelength range, but also other wavelength ranges outside the first wavelength range, especially includes a wavelength shorter than the first wavelength range, thereby causing the color saturation to be deteriorated and the quality of the image display to be degraded.

However, the first light absorption layer 214 can absorb light outside the first wavelength range, and the external light R20 and the first visible light R21 are incident on the first light absorption layer 214 in the reflective cholesteric liquid crystal display 200a, so that the first light absorption layer 214 can allow the first visible light R21 within the first wavelength range to pass through the first light absorption layer 214 and the first upper transparent substrate 211u, and reduce the emergence of the first visible light R21 outside the first wavelength range from the first upper transparent substrate 211 u. Thus, the first light absorption layer 214 is helpful to improve the color saturation of the pixel display and improve the image quality of the reflective cholesteric liquid crystal display 200 a.

Referring to fig. 2B, when the first cholesteric liquid crystal layer 213 is in the focal conic arrangement state, the external light R20 is incident on the first upper transparent substrate 211u, and sequentially passes through the first light absorption layer 214, the first upper transparent electrode pattern 212u and the first cholesteric liquid crystal layer 213 to be incident on the first lower transparent electrode pattern 212d and the first lower substrate 211d, so that the external light R20 can penetrate through the first cholesteric liquid crystal layer 213 in the focal conic arrangement state. In addition, when the external light R20 passes through the first light absorbing layer 214, the first light absorbing layer 214 absorbs the external light R20 outside the first wavelength range, so that the wavelength of the external light R20 passing through the first light absorbing layer 214 is changed to be different from the original wavelength of the external light R20.

The reflective cholesteric liquid crystal display 200a may further include a black light-shielding layer 220, which may be formed of ink or dye resin and may be formed by roll printing or inkjet printing, wherein the black light-shielding layer 220 may be formed on the lower surface D11D of the first lower substrate 211D. Under the condition that the first cholesteric liquid crystal layer 213 is in the focal conic arrangement state, the external light R20 passes through the first lower transparent electrode pattern 212d and the first lower substrate 211d and is incident on the black light-shielding layer 220, so that the black light-shielding layer 220 absorbs the external light R20. At this time, the color of the black light-shielding layer 220 is visible when viewing the display screen (i.e., the upper surface U11U) of the reflective cholesteric liquid crystal display 200 a. Therefore, when the first cholesteric liquid crystal layer 213 is in the focal conic state, the reflective cholesteric liquid crystal display 200a displays a dark image.

Therefore, the first cholesteric liquid crystal layer 213 in the focal conic arrangement state can make the reflective cholesteric liquid crystal display 200a display a dark-state image, and the first cholesteric liquid crystal layer 213 in the planar arrangement state can make the reflective cholesteric liquid crystal display 200a display a bright-state image, so that the reflective cholesteric liquid crystal display 200a can display a bright-dark image, and further display an image. In addition, since the first light absorbing layer 214 can reduce the first visible light R21 outside the first wavelength range from exiting from the first upper transparent substrate 211u, the first light absorbing layer 214 is helpful to improve the color saturation of the pixel display, thereby improving the image quality of the reflective cholesteric liquid crystal display 200 a.

Referring to fig. 2A and 2B, the first display unit 210a may further include a first black pattern 215, wherein the first black pattern 215 may be made of metal, graphite, black photoresist or ink, and the method for forming the first black pattern 215 may include film deposition, spin coating, photolithography, roll printing or jet printing. The first black pattern 215 is positioned between the first upper transparent substrate 211u and the first upper transparent electrode pattern 212 u. Taking fig. 2A and 2B as an example, the first black pattern 215 has a plurality of first grids 215h, and the first light absorption layer 214 is filled in the first grids 215 h. Therefore, a portion of the first light absorbing layer 214 may be located between the first black pattern 215 and the first upper transparent electrode pattern 212u, and the other portion of the first light absorbing layer 214 extends into the first grids 215 h.

Fig. 2D is a schematic top view of the first black pattern in fig. 2A, and fig. 2D is a schematic diagram illustrating the first black pattern 215 when the reflective cholesteric liquid crystal display 200a is viewed along a direction Z1 in fig. 2A. Referring to fig. 2C and 2D, the overlapping areas P21 (for example, the diagonal areas shown in fig. 2C) between the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212D are respectively aligned with the first grids 215h of the first black pattern 215, so that the overlapping areas P21 are not covered by the first black pattern 215, so that the pixels of the reflective cholesteric liquid crystal display 200a can be respectively aligned with the first grids 215 h.

The first black pattern 215 can block the external light R20 and the first visible light R21, so that the external light R20 and the first visible light R21 penetrate the first black pattern 215 from the first grids 215 h. Therefore, the first black pattern 215 may allow the first visible light R21 emitted from the overlapping region P21 to pass through, but may block the first visible light R21 emitted from a region other than the overlapping region P21. Thus, the first black pattern 215 does not substantially cover the pixel, and helps to prevent light leakage, thereby improving contrast of pixel display and image quality.

Referring to fig. 2A and 2B, the first display unit 210a may further include a Sealant (Sealant)216, wherein the Sealant 216 is located between the first upper transparent substrate 211u and the first lower substrate 211d and connects the first upper transparent substrate 211u and the first lower substrate 211 d. The sealant 216 can surround the first cholesteric liquid crystal layer 213, so that the first cholesteric liquid crystal layer 213 is sealed in the accommodating space defined by the first upper transparent substrate 211u, the first lower substrate 211d and the sealant 216 to prevent the first cholesteric liquid crystal layer 213 from leaking.

It should be noted that the potential difference generated between the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d can control the gray level of the pixel (i.e., the overlapping region P21 in fig. 2C), and the potential difference can be adjusted by an external control element (not shown) electrically connected to the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, wherein the external control element is, for example, a Timing Controller (TCON) or a processor.

Fig. 3A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 3A, a reflective cholesteric liquid crystal display 200b shown in fig. 3A is similar to the reflective cholesteric liquid crystal display 200a of the previous embodiment, wherein the reflective cholesteric liquid crystal displays 200a and 200b include the same elements, such as: a first cholesteric liquid crystal layer 213, a sealant 216, and a first light absorbing layer 214. The main difference between the reflective cholesteric liquid crystal displays 200a and 200b is that the first display unit 210b of the reflective cholesteric liquid crystal display 200b includes a plurality of first spacers 217, and the reflective cholesteric liquid crystal display 200b does not include the first black pattern 215. The main differences will be described below, and the same features of the reflective cholesteric liquid crystal displays 200a and 200b will not be repeated in principle.

The first spacers 217 are sandwiched between the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, wherein the first spacers 217 can contact the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d and can be pressed by the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, so that the first cholesteric liquid crystal layer 213 does not flow between the first spacers 217 and the first upper transparent electrode pattern 212u or between the first spacers 217 and the first lower transparent electrode pattern 212 d. In other words, the first cholesteric liquid crystal layer 213 does not enter the area occupied by the first spacers 217 on the first upper transparent substrate 211u and the first lower substrate 211 d.

Fig. 3B is a schematic top view of the first spacers in fig. 3A, and fig. 3B is a schematic diagram illustrating the first spacers 217 viewed from the reflective cholesteric liquid crystal display 200B along a direction Z1 in fig. 3A, wherein the first spacers 217 in fig. 3A are illustrated along a cross section of a line I-I in fig. 3B. Referring to fig. 3A and 3B, each of the first spacers 217 may be a cross-shaped cylinder, such as the cylinder with a cross-shaped bottom surface shown in fig. 3B. The first spacers 217 are arranged in an array and define a plurality of openings 217 h. Taking fig. 3B as an example, four adjacent first spacers 217 surround one opening 217h, and the openings 217h are arranged in an array. These first spacers 217 are separated from each other without contact so that a gap 217g is formed between adjacent two first spacers 217. Therefore, the openings 217h can communicate with each other by the slits 217g, so that the first cholesterol liquid crystal layer 213 can flow between the openings 217 h.

In the reflective cholesteric liquid crystal display 200b, the openings 217h are also respectively aligned with a plurality of overlapping regions P21 (see fig. 2C) between the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, so the openings 217h are also respectively aligned with a plurality of pixels of the reflective cholesteric liquid crystal display 200b, and the first spacers 217 are distributed in a region other than the overlapping region P21 (pixel). Since the first cholesteric liquid crystal layer 213 does not enter the area occupied by the first spacers 217 on the first upper transparent substrate 211u and the first lower substrate 211d, and the first spacers 217 are distributed in the area outside the overlapping areas P21, the first spacers 217 help to prevent light leakage of the first cholesteric liquid crystal layer 213 in the area outside the pixel, so as to improve the contrast of the pixel display and further improve the image quality.

The first spacers 217 may be made of a photoresist material or a resin material. The first spacers 217 made of a photoresist material may be formed using spin coating, photolithography, and the first spacers 217 made of a resin material may be directly formed using inkjet printing. In the embodiment, the first spacer 217 may be transparent, so that light (e.g., the external light R20 and the first visible light R21) can penetrate through the first spacer 217 to increase the light utilization rate of the reflective cholesteric liquid crystal display 200b, thereby improving the brightness of the image. It should be noted, however, that in other embodiments, the first spacer 217 may be opaque. For example, the first spacer 217 may be black in color, like the first black pattern 215. The black opaque first spacer 217 also helps to prevent light leakage, so the first spacer 217 may be transparent or opaque, but the embodiment does not limit the first spacer 217 to be transparent.

In particular, in the embodiments shown in fig. 2A, 2B and 3A, the reflective cholesteric liquid crystal display 200a or 200B may include only one first display unit (i.e., the first display unit 210a or 210B), and the reflective cholesteric liquid crystal display 200a or 200B may be a monochrome display and is suitable for being used as an advertisement sign or an electronic book. However, in other embodiments, the reflective cholesteric liquid crystal display may include at least two display units, and the following description will be provided with reference to the accompanying drawings.

Fig. 4A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 4A, the reflective cholesteric liquid crystal display 300a of the present embodiment includes a first optical transparent adhesive layer 390 and two display units: the first display unit 210a and the second display unit 310a, wherein the first optical transparent adhesive layer 390 is adhered between the first display unit 210a and the second display unit 310a, so that the first display unit 210a and the second display unit 310a are combined together.

The second display unit 310a is similar in construction to the first display unit 210 a. In detail, the second display unit 310a includes a second upper transparent substrate 311u, a second lower transparent substrate 311d, a second upper transparent electrode pattern 312u, a second lower transparent electrode pattern 312d, and a second cholesteric liquid crystal layer 313, wherein the first optically transparent adhesive layer 390 is adhered between the first upper transparent substrate 211u of the first display unit 210a and the second lower transparent substrate 311d of the second display unit 310 a. The second upper transparent electrode pattern 312u is formed on the second upper transparent substrate 311u, and the second lower transparent electrode pattern 312d is formed on the second lower transparent substrate 311d, wherein the second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312d face each other.

Both the second upper transparent substrate 311u and the second lower transparent substrate 311d may be the same as the first upper transparent substrate 211u, i.e., the second upper transparent substrate 311u and the second lower transparent substrate 311d may be rigid substrates (e.g., glass plates or PMMA substrates) or flexible substrates (e.g., PI substrates or PET substrates). The second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312d may be the same as the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, respectively. In detail, both the second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312d may be formed of the same material as both the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, wherein the shape of the second upper transparent electrode pattern 312u may be the same as that of the first upper transparent electrode pattern 212u, and the shape of the second lower transparent electrode pattern 312d may be the same as that of the first lower transparent electrode pattern 212d, as shown in fig. 2C.

The second cholesteric liquid crystal layer 313 is sandwiched between the second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312d, wherein the second cholesteric liquid crystal layer 313 is controlled to be in a focal conic alignment state or a planar alignment state by an electric field generated between the second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312d, and both the first cholesteric liquid crystal layer 213 and the second cholesteric liquid crystal layer 313 shown in fig. 4A are in a planar alignment state. In addition, the second display unit 310a may further include a sealant 216 disposed between the second upper transparent substrate 311u and the second lower transparent substrate 311d and connecting the second upper transparent substrate 311u and the second lower transparent substrate 311 d. The sealant 216 can also surround and seal the second cholesteric liquid crystal layer 313 to prevent the second cholesteric liquid crystal layer 313 from leaking.

When the external light R20 is incident on the reflective cholesteric liquid crystal display 300a from the second upper transparent substrate 311u, the first cholesteric liquid crystal layer 213 in the planar arrangement state can reflect the first visible light R21 in the external light R20, and the second cholesteric liquid crystal layer 313 in the planar arrangement state can reflect the second visible light R31 in the external light R20. Therefore, the first cholesteric liquid crystal layer 213 and the second cholesteric liquid crystal layer 313 can generate the first visible light R21 and the second visible light R31, respectively.

The second visible light R31 includes a specific second wavelength range and may be light having a specific color, such as green or blue light, wherein the second wavelength range may be a wavelength range of a certain color, such as a green wavelength range between 500 nm and 590 nm or a blue wavelength range between 415 nm and 500 nm. It should be noted that the second visible light R31 includes not only the second wavelength range but also other wavelength ranges outside the second wavelength range, so the second wavelength range is not equal to the entire wavelength range of the second visible light R31. In addition, the second wavelength range of the second visible light R31 is different from the first wavelength range of the first visible light R21, so the color of the first visible light R21 may be different from the color of the second visible light R31. For example, the first visible light R21 can be red light, and the second visible light R31 can be green light.

The second display unit 310a further includes a second light absorbing layer 314b, wherein the second light absorbing layer 314b is formed on a second upper transparent substrate 311 u. The meaning of the phrase "the second light absorbing layer 314b is formed on the second upper transparent substrate 311 u" as in the above embodiments, covers the contact and non-contact of the second light absorbing layer 314b with the second upper transparent substrate 311u, that is, the second light absorbing layer 314b can be formed on the surface of the second upper transparent substrate 311u and can contact or not contact the second upper transparent substrate 311 u. For example, in FIG. 4A, the second light absorbing layer 314b can be formed between the second upper transparent substrate 311u and the second upper transparent electrode pattern 312 u. Alternatively, the second upper transparent substrate 311u may be positioned between the second upper transparent electrode pattern 312u and the second light absorbing layer 314 b. Therefore, fig. 4A does not limit the second light absorbing layer 314b to be formed only between the second upper transparent substrate 311u and the second upper transparent electrode pattern 312 u.

The method of forming the second light absorbing layer 314b may be the same as the method of forming the first light absorbing layer 214, and the second light absorbing layer 314b may be made of a photoresist material or ink. However, the first light absorbing layer 214 and the second light absorbing layer 314b are different from each other in optical characteristics. The first light-absorbing layer 214 can absorb light outside the first wavelength range, and the second light-absorbing layer 314b can absorb light outside both the first wavelength range and the second wavelength range, so that the first visible light R21 in the first wavelength range and the second visible light R31 in the second wavelength range can pass through the second light-absorbing layer 314b and the second upper transparent substrate 311 u. Thus, the first light absorbing layer 214 can reduce the emission of the first visible light R21 outside the first wavelength range from the second upper transparent substrate 311u, and the second light absorbing layer 314b can reduce the emission of the second visible light R31 outside the second wavelength range from the second upper transparent substrate 311u, so as to improve the image quality of the reflective cholesteric liquid crystal display 300 a.

In addition, the second display unit 310a may further include a second black pattern 315, and the second black pattern 315 may be formed between the second upper transparent substrate 311u and the second upper transparent electrode pattern 312 u. Not only the constituent materials and the formation methods of both the second black pattern 315 and the first black pattern 215 may be the same as each other, but also the shapes of both may be the same as each other. In other words, the second black pattern 315 has a plurality of second cells 315h, and the shape of the second cells 315h can be similar to the first cells 215h shown in fig. 2D, wherein a plurality of overlapping areas (please refer to the overlapping area P21 in fig. 2C) between the second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312D are respectively aligned with the second cells 315 h. In addition, the second light absorption layer 314b may also be filled in the second grids 315h, as shown in fig. 4A.

Fig. 4B is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 4B, the reflective cholesteric liquid crystal display 300B includes a first display unit 210B, a second display unit 310B, and a first optical transparent adhesive layer 390, wherein the first optical transparent adhesive layer 390 is adhered between the first display unit 210B and the second display unit 310B, so that the first display unit 210B and the second display unit 310B are combined together. In addition, the reflective cholesteric liquid crystal display 300B in fig. 4B is similar to the reflective cholesteric liquid crystal display 300a in fig. 4A. For example, both the second display unit 310B in fig. 4B and the second display unit 310a in fig. 4A include the same elements.

The main difference between the reflective cholesteric liquid crystal displays 300a and 300b is: the reflective cholesteric liquid crystal display 300b does not include the first black pattern 215 and the second black pattern 315, and the second display unit 310b further includes a plurality of second spacers 317. Therefore, the reflective cholesteric liquid crystal display 300B in fig. 4B employs the first spacer 217 and the second spacer 317 instead of the first black pattern 215 and the second black pattern 315 in fig. 4A, respectively.

The second spacers 317 are sandwiched between the second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312d, and can be separated from each other without contacting each other, so that a gap is formed between two adjacent second spacers 317, wherein the shape and arrangement of the second spacers 317 can be the same as the shape and arrangement of the first spacers 217, as shown in fig. 3B. Therefore, the second spacers 317 can also define a plurality of openings 317 h. In addition, the constituent materials, the forming methods, and the functions of the first spacer 217 and the second spacer 317 may be the same as each other, and the constituent materials, the forming methods, and the functions of the first spacer 217 are described in the foregoing embodiments, and thus, the description thereof is not repeated.

Fig. 5A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 5A, a reflective cholesteric liquid crystal display 300c of the present embodiment is similar to the reflective cholesteric liquid crystal display 300a of the embodiment of fig. 4A, and further includes a first optically transparent adhesive layer 390 and two display units: the first display unit 210c and the second display unit 310c, wherein the first optical transparent adhesive layer 390 is adhered between the first display unit 210c and the second display unit 310c, so that the first display unit 210c and the second display unit 310c are combined together.

The first display unit 210c is similar to the first display unit 210a in fig. 4A, and both the first display units 210a and 210c include the same elements, such as the first black pattern 215 and the sealant 216. Similarly, the second display unit 310c is similar to the second display unit 310a in fig. 4A, and both the second display units 310a and 310c include the same elements, such as the second black pattern 315 and the sealant 216. Unlike the reflective cholesteric liquid crystal display 300a in fig. 4A, the first display unit 210c does not include the first light absorbing layer 214, and the second display unit 310c includes two light absorbing layers: a first light absorbing layer 314a and a second light absorbing layer 314b, wherein the first light absorbing layer 314a is formed on the second lower transparent substrate 311d, and the second light absorbing layer 314b is formed on the second upper transparent substrate 311 u. Therefore, the second display unit 310c has one more first light absorbing layer 314a than the second display unit 310 a.

The meaning of "the first light absorbing layer 314a is formed on the second lower transparent substrate 311 d" also covers the first light absorbing layer 314a contacting and not contacting the second lower transparent substrate 311d, that is, the first light absorbing layer 314a is formed on the surface of the second lower transparent substrate 311d and may contact or not contact the second lower transparent substrate 311d, as in the above-mentioned embodiment "the second light absorbing layer 314b is formed on the second upper transparent substrate 311 u". For example, in fig. 5A, the first light absorbing layer 314a may be formed between the second lower transparent substrate 311d and the second lower transparent electrode pattern 312 d. Alternatively, the second lower transparent substrate 311d may be positioned between the second lower transparent electrode pattern 312d and the first light absorbing layer 314 a. Therefore, fig. 5A does not limit that the first light absorbing layer 314a can only be formed between the second lower transparent substrate 311d and the second lower transparent electrode pattern 312 d.

The first light absorbing layer 314a may be the same as the first light absorbing layer 214, and thus the constituent materials, formation methods, and optical characteristics of both the first light absorbing layers 214 and 314a may be the same as each other. In other words, the first light absorption layer 314A can also absorb light outside the first wavelength range, so that the first visible light R21 (see fig. 4A) in the first wavelength range can also pass through the first light absorption layer 314A. Since the second light absorbing layer 314b can absorb light rays outside both the first wavelength range and the second wavelength range, the first visible light R21 passing through the first light absorbing layer 314a can also pass through the second light absorbing layer 314b and the second upper transparent substrate 311u together with the second visible light R31 within the second wavelength range. The first light absorbing layer 314a and the second light absorbing layer 314b absorb light outside the first and second wavelength ranges, so that the image quality of the reflective cholesteric liquid crystal display 300c is improved.

FIG. 5B is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 5B, the reflective cholesteric liquid crystal display 300d includes a first display unit 210d, a second display unit 310d and a first optical transparent adhesive layer 390, wherein the first optical transparent adhesive layer 390 is adhered between the first display unit 210d and the second display unit 310d to combine the first display unit 210d and the second display unit 310d together. The reflective cholesteric liquid crystal display 300d is similar to the reflective cholesteric liquid crystal display 300c in FIG. 5A. Specifically, the first display unit 210d in fig. 5B and the first display unit 210c in fig. 5A both include the same elements, and the second display unit 310d in fig. 5B and the second display unit 310c in fig. 5A both include the same elements. In addition, the first display unit 210d is more similar to the first display unit 210b of fig. 3A, but the difference between the first display units 210d and 210b is only that: the first display unit 210d does not have the first light absorbing layer 214.

Unlike the reflective cholesteric liquid crystal display 300c in fig. 5A, the first display unit 210d includes a plurality of first spacers 217, and the second display unit 310d includes a plurality of second spacers 317, wherein the reflective cholesteric liquid crystal display 300d does not include the first black pattern 215 and the second black pattern 315. In the reflective cholesteric liquid crystal display 300d shown in fig. 5B, the first spacers 217 are interposed between the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, and the second spacers 317 are interposed between the second upper transparent electrode pattern 312u and the second lower transparent electrode pattern 312 d. Therefore, in the reflective cholesteric liquid crystal display 300d in fig. 5B, the first and second spacers 217 and 317 are used to replace the first and second black patterns 215 and 315 in fig. 5A.

In particular, the reflective cholesteric liquid crystal displays 300a to 300d shown in fig. 4A, 4B, 5A and 5B are only examples, and various reflective cholesteric liquid crystal displays not shown in the drawings are still disclosed in the present invention. In detail, in the embodiment shown in fig. 4A and 4B, any one of the first display units 210a and 210B can be combined with any one of the second display units 310a and 310B by using the first optically transparent adhesive layer 390. Therefore, in other embodiments not shown, the reflective cholesteric liquid crystal display may include a black pattern (e.g., the first black pattern 215 or the second black pattern 315) and a plurality of spacers (e.g., the first spacer 217 or the second spacer 317). For example, the reflective cholesteric liquid crystal display may include a first black pattern 215 and a plurality of second spacers 317, or a plurality of first spacers 217 and a plurality of second black patterns 315. Therefore, the black pattern and the spacer can exist in the same reflective cholesteric liquid crystal display, not limited to fig. 4A, fig. 4B, fig. 5A and fig. 5B.

Fig. 6A is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 6A, the reflective cholesteric liquid crystal display 400a of the present embodiment includes a first optical transparent adhesive layer 390, a second optical transparent adhesive layer 490, and three display units: the first display unit 210a, the second display unit 310a and the third display unit 410a, wherein the first optical transparent adhesive layer 390 is adhered between the first display unit 210a and the second display unit 310a, and the second optical transparent adhesive layer 490 is adhered between the second display unit 310a and the third display unit 410a, so that the first display unit 210a, the second display unit 310a and the third display unit 410a are combined together. In addition, as shown in fig. 6A, the reflective cholesteric liquid crystal display 400a is substantially the reflective cholesteric liquid crystal display 300a in fig. 4A, which is formed by combining the second optically transparent adhesive layer 490 and the third display unit 410 a.

The configuration of the third display unit 410a is similar to that of the first display unit 210a or the second display unit 310a, but the third display unit 410a does not include any light absorbing layer, such as the first light absorbing layer 214 or the second light absorbing layer 314 b. The third display unit 410a includes a third upper transparent substrate 411u, a third lower transparent substrate 411d, a third upper transparent electrode pattern 412u, a third lower transparent electrode pattern 412d and a third cholesteric liquid crystal layer 413, wherein the second optically transparent adhesive layer 490 is adhered between the second upper transparent substrate 311u and the third lower transparent substrate 411 d.

The third upper transparent electrode pattern 412u is formed on the third upper transparent substrate 411u, and the third lower transparent electrode pattern 412d is formed on the third lower transparent substrate 411d, wherein the third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412d face each other, and the third cholesteric liquid crystal layer 413 is interposed between the third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412 d. In addition, the third display unit 410a may further include a sealant 216 disposed between the third upper transparent substrate 411u and the third lower transparent substrate 411d and connecting the third upper transparent substrate 411u and the third lower transparent substrate 411 d. The sealant 216 can also surround and seal the third cholesteric liquid crystal layer 413 to prevent the third cholesteric liquid crystal layer 413 from leaking.

Both the third upper transparent substrate 411u and the third lower transparent substrate 411d may be identical to the first upper transparent substrate 211u, i.e., both the third upper transparent substrate 411u and the third lower transparent substrate 411d may be rigid substrates (e.g., glass plates or PMMA substrates) or flexible substrates (e.g., PI substrates or PET substrates). The third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412d may be the same as the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, respectively. That is, both the third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412d may be formed of the same material as both the first upper transparent electrode pattern 212u and the first lower transparent electrode pattern 212d, wherein the third upper transparent electrode pattern 412u may have the same shape as the first upper transparent electrode pattern 212u, and the third lower transparent electrode pattern 412d may have the same shape as the first lower transparent electrode pattern 212d, as shown in fig. 2C.

The third cholesteric liquid crystal layer 413 is interposed between the third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412 d. As in the previous embodiments, the electric field generated between the third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412d can control the third cholesteric liquid crystal layer 413 to be in a focal conic alignment state or a planar alignment state, wherein the first cholesteric liquid crystal layer 213, the second cholesteric liquid crystal layer 313 and the third cholesteric liquid crystal layer 413 shown in fig. 6A are all in a planar alignment state. When the external light R20 is incident on the reflective cholesteric liquid crystal display 400a from the third upper transparent substrate 411u, the third cholesteric liquid crystal layer 413 in the planar arrangement state can reflect the third visible light R41 in the external light R20, that is, the third cholesteric liquid crystal layer 413 can generate the third visible light R41, wherein the first visible light R21, the second visible light R31 and the third visible light R41 all can pass through the third upper transparent substrate 411 u.

The third visible light R41 may include a specific third wavelength range and may be light having a specific color, such as blue light, and the third wavelength range may be a wavelength range of a certain color, such as a blue light wavelength range between 415 nm and 500 nm. In addition, the third wavelength range of the third visible light R41 is different from the first wavelength range of the first visible light R21 and the second wavelength range of the second visible light R31, so the color of the third visible light R41 is different from the colors of both the first visible light R21 and the second visible light R31. For example, the first visible light R21 can be red light, the second visible light R31 can be green light, and the third visible light R41 can be blue light, wherein the first visible light R21, the second visible light R31, and the third visible light R41 can make the reflective cholesteric liquid crystal display 400a display a color image.

In addition, the third display unit 410a may further include a third black pattern 415, and the third black pattern 415 may be formed between the third upper transparent substrate 411u and the third upper transparent electrode pattern 412 u. Constituent materials, forming methods, and shapes of both the third black pattern 415 and the first black pattern 215 may be the same as each other. For example, the third black pattern 415 has a plurality of third grids 415h, and the shape and distribution of the third grids 415h may be the same as the first grid 215h shown in fig. 2D. In addition, a plurality of overlapping areas (please refer to overlapping area P21 in fig. 2C) between the third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412d are respectively aligned with the third grids 415 h.

FIG. 6B is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 6B, the reflective cholesteric liquid crystal display 400B of the present embodiment is similar to the reflective cholesteric liquid crystal display 400a of the previous embodiment, and further includes a first optical transparent adhesive layer 390, a second optical transparent adhesive layer 490, and three display units: the first display unit 210a, the second display unit 310e and the third display unit 410b, wherein the first optical transparent adhesive layer 390 is adhered between the first display unit 210a and the second display unit 310e, and the second optical transparent adhesive layer 490 is adhered between the second display unit 310e and the third display unit 410b, so that the first display unit 210a, the second display unit 310e and the third display unit 410b are combined together.

The second display unit 310e does not include the first light absorbing layer 314a and the second light absorbing layer 314b, as in the first display unit 210c, so the second display unit 310e is similar to the first display unit 210c in FIG. 5A. The second display unit 310e is also similar to the second display unit 310a in fig. 6A, and both also include the same elements. However, unlike the second display unit 310a in fig. 6A, the second display unit 310e does not have the second light absorbing layer 314 b. The third display unit 410b is similar to the third display unit 410a in fig. 6A, and both also include the same elements. Except that the third display unit 410b further includes a second light absorbing layer 414 than the third display unit 410a, wherein the second light absorbing layer 414 is formed on the third lower transparent substrate 411 d.

The meaning of the phrase "the second light absorbing layer 414 is formed on the third lower transparent substrate 411 d" also covers the contact and non-contact of the second light absorbing layer 414 with the third lower transparent substrate 411d, that is, the second light absorbing layer 414 can be formed on the surface of the third lower transparent substrate 411d and can contact or not contact the third lower transparent substrate 411d, as in the above-mentioned embodiments where the first light absorbing layer 214 is formed on the first upper transparent substrate 211u ". For example, in FIG. 6B, the second light absorbing layer 414 can be formed between the third bottom transparent substrate 411d and the third bottom transparent electrode pattern 412 d. Alternatively, the third lower transparent substrate 411d may be positioned between the third lower transparent electrode pattern 412d and the second light absorbing layer 414. Therefore, fig. 6B does not limit the second light absorbing layer 414 to be formed only between the third lower transparent substrate 411d and the third lower transparent electrode pattern 412 d.

The second light absorbing layer 414 may be the same as the second light absorbing layer 314b, and thus the constituent materials, formation methods, and optical characteristics of both the second light absorbing layers 414 and 314b may be the same as each other. Therefore, the second light absorbing layer 414 can also absorb light outside of both the first wavelength range and the second wavelength range, so that the first visible light R21 in the first wavelength range and the second visible light R31 in the second wavelength range both pass through the second light absorbing layer 414 and the third upper transparent substrate 411 u. In addition, in the reflective cholesteric liquid crystal display 400a shown in fig. 6A, if the second light absorbing layer 314B is moved between the third lower transparent electrode pattern 412d and the third lower transparent substrate 411d, the reflective cholesteric liquid crystal display 400B shown in fig. 6B is substantially formed. The first and second light absorbing layers 214 and 414 can reduce the emission of the first visible light R21 outside the first wavelength range and the second visible light R31 outside the second wavelength range from the third upper transparent substrate 411u, thereby improving the image quality of the reflective cholesteric liquid crystal display 400 b.

FIG. 6C is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 6C, the reflective cholesteric liquid crystal display 400C shown in fig. 6C is similar to the reflective cholesteric liquid crystal display 400B shown in fig. 6B, and both the reflective cholesteric liquid crystal displays 400C and 400B include the same elements, such as the third display unit 410B, the first optical transparent adhesive layer 390 and the second optical transparent adhesive layer 490, wherein the reflective cholesteric liquid crystal display 400C further includes the first display unit 210C and the second display unit 310 f. The difference between the reflective cholesteric liquid crystal displays 400c and 400b will be mainly described below.

Unlike the reflective cholesteric liquid crystal display 400B of fig. 6B, the first display unit 210c does not include the first light absorbing layer 214, and the second display unit 310f and the third display unit 410B respectively include the first light absorbing layer 314a and the second light absorbing layer 414. The first light absorbing layer 314a may be the same as the first light absorbing layer 214, and in the reflective cholesteric liquid crystal display 400B shown in fig. 6B, if the first light absorbing layer 214 is moved between the second lower transparent electrode pattern 312d and the second lower transparent substrate 311d, a reflective cholesteric liquid crystal display 400C shown in fig. 6C is substantially formed. Further, the second display unit 310f is also similar to the second display unit 310c in fig. 5A, but the main difference between the two is only: the second display unit 310f has one less second light absorbing layer 314b than the second display unit 310 c.

FIG. 6D is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 6D, the reflective cholesteric liquid crystal display 400D shown in fig. 6D is similar to the previous embodiments, wherein the reflective cholesteric liquid crystal display 400D includes the first display unit 210c, the second display unit 310c and the third display unit 410 a. In addition, the reflective cholesteric liquid crystal display 400D in fig. 6D is similar to the reflective cholesteric liquid crystal display 300c in fig. 5A, and the main difference between the two is only: the reflective cholesteric liquid crystal display 400d has more third display units 410a than the reflective cholesteric liquid crystal display 300c of fig. 5A. In other words, the reflective cholesteric liquid crystal display 400D in fig. 6D substantially includes the reflective cholesteric liquid crystal display 300c and the third display unit 410a in fig. 5A.

In particular, in the embodiments shown in fig. 6A to 6D, the reflective cholesteric liquid crystal displays 400a to 400D respectively include the first black pattern 215, the second black pattern 315 and the third black pattern 415, but do not include any spacers (e.g., the first spacer 217 and the second spacer 317). However, in other embodiments, at least one of the first black pattern 215, the second black pattern 315 and the third black pattern 415 in the reflective cholesteric liquid crystal displays 400a to 400d may be replaced with a plurality of spacers, such as the third spacers 417 shown in fig. 7.

FIG. 7 is a schematic cross-sectional view of a reflective cholesteric liquid crystal display according to another embodiment of the invention. Referring to fig. 7, the reflective cholesteric liquid crystal display 400e includes a first display unit 210, a second display unit 310, a third display unit 410c, a first optical transparent adhesive layer 390 and a second optical transparent adhesive layer 490. The first optical transparent adhesive layer 390 is adhered between the first display unit 210 and the second display unit 310, and the second optical transparent adhesive layer 490 is adhered between the second display unit 310 and the third display unit 410c, so that the first display unit 210, the second display unit 310 and the third display unit 410c are combined together.

The first display unit 210 may be the first display unit 210a, 210b, 210c, or 210d in the foregoing embodiment, and the second display unit 310 may be the second display unit 310a, 310b, 310c, 310d, 310e, or 310f in the foregoing embodiment. Therefore, the reflective cholesteric liquid crystal display 400e is similar to the reflective cholesteric liquid crystal display in the previous embodiment. The reflective cholesteric liquid crystal display 400e may include a black pattern (e.g., the first black pattern 215 or the second black pattern 315) and a plurality of spacers (e.g., the first spacer 217 or the second spacer 317). Alternatively, the reflective cholesteric liquid crystal display 400e may also include the first spacer 217 and the second spacer 317, but not the first black pattern 215, the second black pattern 315 and the third black pattern 415. The reflective cholesteric liquid crystal display 400e includes at least one light absorbing layer (e.g., the first light absorbing layers 214, 314a and the second light absorbing layer 314 b). For example, the reflective cholesteric liquid crystal display 400e includes only the first light absorbing layer 214. Alternatively, the reflective cholesteric liquid crystal display 400e includes the first light absorbing layer 214 and the second light absorbing layer 314 b.

The third display unit 410c further includes a plurality of third spacers 417, wherein the third spacers 417 are sandwiched between the third upper transparent electrode pattern 412u and the third lower transparent electrode pattern 412d, and can be separated from each other without contacting, so that a gap is formed between two adjacent third spacers 417, wherein the third spacers 417 can also define a plurality of openings 417 h. In addition, the shape, arrangement, constituent material, forming method and efficacy of the third spacer 417 and the first spacer 217 are the same as each other, as shown in fig. 3B, and thus, the description thereof is not repeated.

In particular, in the reflective cholesteric liquid crystal display 400e shown in fig. 7, the second light absorbing layer 414 may be formed between the third lower transparent substrate 411d and the third lower transparent electrode pattern 412d, and the total number of light absorbing layers included in both the first display unit 210 and the second display unit 310 may be only one. Taking fig. 4B as an example, the first display unit 210 is a first display unit 210B, and the second display unit 310 is a second display unit 310B. Therefore, the third display unit 410c in fig. 7 may also include the second light absorbing layer 414, so fig. 7 is only for illustration and is not intended to limit the third display unit 410 c.

Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited to the above embodiments, and that various changes and modifications can be made by those skilled in the art without departing from the scope of the invention.