阅读说明：本技术 两面发光照明装置 (Two-sided light-emitting lighting device ) 是由 张夏准 朴伦正 申京任 于 2018-12-05 设计创作，主要内容包括：本公开涉及一种两面发光照明装置,其使散射效果最大化,从而能够提高光提取效率,并且可以作为两面发光照明装置而获得高功率效率,从而增加照明装置的使用寿命。本公开的两面发光照明装置包括：第一发光面；第二发光面,其位于所述第一发光面相对的位置；发光器件,其位于所述第一发光面与所述第二发光面之间,朝所述第一发光面方向发射第一光,朝所述第二发光面方向发射第二光；基材,其位于所述第一发光面,具有相对的第一面与第二面,并且配备为所述第一光入射到所述第一面后从所述第二面发射；以及光提取膜,其包括不规则地分布于所述基材内的多个孔,其中,所述基材用于散射透射所述基材时的所述光,所述散射包括由所述孔颗粒引起的第一散射与由所述第一面、第二面中至少一个引起的第二散射,所述基材配备为由所述第一散射引起的第一散射度与由第二散射引起的第二散射度具有相对的差异性。(The present disclosure relates to a two-sided light emitting lighting device which maximizes a scattering effect so that light extraction efficiency can be improved, and can obtain high power efficiency as a two-sided light emitting lighting device so that the life span of the lighting device is increased. The two-sided light emitting lighting device of the present disclosure includes: a first light emitting surface; a second light emitting surface located opposite to the first light emitting surface; a light emitting device located between the first light emitting surface and the second light emitting surface, emitting first light in a direction of the first light emitting surface, and emitting second light in a direction of the second light emitting surface; a substrate positioned in the first light-emitting face, having first and second opposing faces, and configured such that the first light is incident on the first face and emitted from the second face; and a light extraction film comprising a plurality of pores irregularly distributed within the substrate, wherein the substrate is configured to scatter the light when transmitted through the substrate, the scattering comprising a first scattering by the pore particles and a second scattering by at least one of the first and second faces, the substrate being equipped such that a first degree of scattering by the first scattering is different from a second degree of scattering by the second scattering.)

1. A two-sided light emitting lighting device, comprising:

a first light emitting surface;

a second light emitting surface located opposite to the first light emitting surface;

a light emitting device located between the first light emitting surface and the second light emitting surface, emitting first light in a direction of the first light emitting surface, and emitting second light in a direction of the second light emitting surface;

a substrate positioned in the first light-emitting face, having first and second opposing faces, and configured such that the first light is incident on the first face and emitted from the second face; and

a light extraction film comprising a plurality of holes irregularly distributed within the substrate,

wherein the substrate is configured to scatter the first light when transmitted through the substrate, the scattering comprising a first scattering by the pore particles and a second scattering by at least one of the first and second faces, the substrate being equipped such that a first degree of scattering by the first scattering is relatively different from a second degree of scattering by the second scattering.

2. A two-sided light emitting lighting device as recited in claim 1,

the substrate has a light transmittance of 70% or more when a first degree of scattering caused by the first scattering is greater than a second degree of scattering caused by the second scattering.

3. A two-sided light emitting lighting device as recited in claim 1,

the substrate has a light transmittance of less than 70% when a second degree of scattering due to the second scattering is greater than a first degree of scattering due to the first scattering.

4. A two-sided light emitting lighting device as recited in claim 1,

the substrate has a light reflectance of less than 20% when a first degree of scattering caused by the first scattering is greater than a second degree of scattering caused by the second scattering.

5. A two-sided light emitting lighting device as recited in claim 1,

when a second degree of scattering caused by the second scattering is greater than a first degree of scattering caused by the first scattering, the light reflectance of the base material is greater than or equal to 20%.

6. A two-sided light emitting lighting device as recited in claim 1,

the holes each have a first diameter when a first degree of scattering caused by the first scattering is greater than a second degree of scattering caused by the second scattering, and a second diameter when a second degree of scattering caused by the second scattering is greater than the first degree of scattering caused by the first scattering, and the first diameter is greater than the second diameter.

7. A two-sided light emitting lighting device as recited in claim 1,

at least one of the first and second facets has a first roughness when a first degree of scattering caused by the first scattering is greater than a second degree of scattering caused by the second scattering, and has a second roughness when a second degree of scattering caused by the second scattering is greater than the first degree of scattering caused by the first scattering, and the second roughness is greater than the first roughness.

Technical Field

The disclosed embodiments relate to a two-sided light emitting lighting device.

Background

A self-light emitting device such as an organic light emitting device can be used for a surface light emitting illumination apparatus, but light generated in a light emitting layer must pass through many interfaces until being emitted from a light extraction surface, and therefore, a lot of light loss occurs in the process, thereby causing a problem of lowering light extraction efficiency. The reduction in light extraction efficiency may increase power consumption, which may shorten the lifespan of the lighting device.

In addition, the lighting device can emit light from both sides, i.e., the back and front sides, but it is difficult to adjust the brightness in the back and front directions, respectively.

Disclosure of Invention

Technical problem

As described above, in order to solve the problem of the reduction of light extraction efficiency in the dual emission lighting apparatus, an embodiment of the present invention provides a dual emission lighting apparatus with higher light extraction efficiency and improved power efficiency.

In addition, the brightness in both directions can be adjusted with a simple method.

Technical scheme

To achieve the object, an embodiment of the present invention may provide a two-sided light emitting lighting device including: a first light emitting surface; a second light emitting surface located opposite to the first light emitting surface; a light emitting device located between the first light emitting surface and the second light emitting surface, emitting first light in a direction of the first light emitting surface, and emitting second light in a direction of the second light emitting surface; a substrate positioned in the first light-emitting face, having first and second opposing faces, and configured such that the first light is incident on the first face and emitted from the second face; and a light extraction film including a plurality of holes irregularly distributed within the substrate, wherein the substrate is configured to scatter the first light when transmitted therethrough, the scattering including a first scattering caused by the hole particles and a second scattering caused by at least one of the first face and the second face, and the substrate is equipped such that a first degree of scattering caused by the first scattering and a second degree of scattering caused by the second scattering have a relative difference.

When the first degree of scattering caused by the first scattering is greater than the second degree of scattering caused by the second scattering, the substrate may have a light transmittance of greater than or equal to 70%.

When the second degree of scattering caused by the second scattering is greater than the first degree of scattering caused by the first scattering, the substrate may have a light transmittance of less than 70%.

When the first degree of scattering caused by the first scattering is greater than the second degree of scattering caused by the second scattering, the substrate may have a light reflectance of less than 20%.

When the second degree of scattering caused by the second scattering is greater than the first degree of scattering caused by the first scattering, the light reflectance of the substrate may be greater than or equal to 20%.

The holes may each have a first diameter when a first degree of scattering caused by the first scattering is greater than a second degree of scattering caused by the second scattering, and may each have a second diameter when the second degree of scattering caused by the second scattering is greater than the first degree of scattering caused by the first scattering, and the first diameter may be greater than the second diameter.

At least one of the first and second faces may have a first roughness when a first degree of scattering caused by the first scattering is greater than a second degree of scattering caused by the second scattering, and at least one of the first and second faces may have a second roughness when a second degree of scattering caused by the second scattering is greater than the first degree of scattering caused by the first scattering, and the second roughness may be greater than the first roughness.

Advantageous effects

Light extraction efficiency may be improved according to one or more embodiments of the present invention as described above.

As the double-sided light-emitting illumination device, high power efficiency can be obtained, and therefore, the service life of the double-sided light-emitting illumination device can be improved.

A simple adjustment of the brightness in both directions can be achieved.

The present invention can be used as a double-sided light-emitting illumination device for a transparent illumination device through which external light can be transmitted. In this case, the light emitting efficiency and the brightness adjustment in two directions can be realized, thereby further improving the illumination effect.

Drawings

Fig. 1 is a sectional view schematically showing a light extraction film according to an embodiment.

Fig. 2 is a sectional view schematically showing a light extraction film according to another embodiment.

Fig. 3 is a sectional view schematically showing a two-side light emitting lighting device according to another embodiment.

Fig. 4 is a sectional view schematically showing a two-side light emitting lighting device according to another embodiment.

Fig. 5 is a partial cross-sectional view illustrating an embodiment of an organic light emitting unit.

FIG. 6 is a cross-sectional SEM image a and a surface SEM image b of the first embodiment.

FIG. 7 is a cross-sectional SEM image a and a surface SEM image b of the second embodiment.

Fig. 8 shows the total transmittance of the wavelength band in the visible light region according to the first embodiment (a) and the second embodiment (B).

Fig. 10 shows optical haze values of wavelength bands in the visible light region according to the first embodiment (a) and the second embodiment (B).

Fig. 11 shows the power efficiency of the first embodiment (a) and the second embodiment (B) and the comparative example (ref).

Fig. 12 shows changes in luminance of light in the first direction that occur according to changes in current of the first embodiment (a) and the second embodiment (B) and the comparative example (ref).

Fig. 13 shows changes in luminance of light in the second direction occurring according to changes in current of the first embodiment (a) and the second embodiment (B) and the comparative example (ref).

Detailed Description

While the invention is susceptible to various modifications and alternative embodiments, specific embodiments thereof are shown in the drawings and will herein be described in detail. The effects, features, and methods of achieving the effects and features of the present invention will become more apparent with reference to the embodiments and the accompanying drawings described in detail below. The present invention is not limited to the embodiments disclosed below, but may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same reference numerals are given to the same or corresponding technical features when described with reference to the drawings, and the repetitive description thereof will be omitted.

In the following embodiments, expressions in the singular include expressions in the plural unless the context clearly dictates otherwise.

In the following embodiments, the terms "including" or "having" and the like mean that the features or components described in the present specification exist, and do not preclude the possibility of adding one or more other features or components.

In the following embodiments, when a part of a film, a region, a component, or the like is located on another film, a region, a component, or the like, not only the case where it is located on another film, a region, a component, or the like, but also the case where another film, a region, a component, or the like is interposed therebetween is included.

Where certain embodiments may be implemented differently, certain engineering orders may be performed differently than illustrated. For example, two projects described in succession may be executed substantially concurrently, or may be executed in the reverse order to the order described.

In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily illustrated for convenience of explanation, and thus the present invention is not limited to the illustrated contents.

Fig. 1 is a sectional view schematically showing a light extraction film 1 according to an embodiment.

As shown in fig. 1, a light extraction film 1 according to an embodiment of the present invention may include a substrate 101 and a plurality of holes 102 irregularly distributed in the substrate 101.

The substrate 101 may comprise a light transmissive polymer material, such as according to one embodiment, it may comprise polyimide. The substrate 101 may be equipped to have flexibility.

The substrate 101 has a first side 11 and a second side 12 opposite to each other, and in this case, the first side 11 may be an incident surface on which light is incident, and the second side 12 may be an emitting surface from which light is emitted. Thus, light may be incident into the substrate 101 via the first side 11 and may be emitted through the second side 12.

The plurality of holes 102 may be irregularly distributed between the first face 11 and the second face 12 of the substrate 101. The holes 102 may serve as light scattering particles and may form hollow cavities having the refractive index of air in the space.

When light is transmitted through the substrate 101, the substrate 101 may scatter light.

The scattering may include a first scattering S1 caused by the hole 102 and a second scattering S2 caused by at least one of the first face 11 and the second face 12.

The light transmitted through the base material 101 collides with the holes 102 irregularly distributed on the optical path thereof, and the light is scattered due to the difference in refractive index between the air in the holes 102 and the polymer constituting the base material 101. The first Scattering S1 may include Mie Scattering (Mie Scattering). The first scattering S1 may scatter most of the light in the form of diffusion in the traveling direction of the light.

In addition, the light transmitted through the substrate 101 may be scattered by at least one of the first face 11 (i.e., the incident surface) and the second face 12 (i.e., the emission surface) (second scattering S2). According to one embodiment, the second scattering S2 may include scattering caused by the second face 12. The second Scattering S2 may include Surface Scattering (Surface Scattering). According to the second scattering S2, the scattered light may propagate not only in the traveling direction of the light but also in other directions than the traveling direction, i.e., in the side and/or rear direction.

The light extraction film 1 according to an embodiment may be provided that a first degree of scattering caused by the first scattering S1 has a corresponding difference from a second degree of scattering caused by the second scattering S2. That is, the light extraction film 1 according to an embodiment may be provided in accordance with desired optical characteristics such that a first degree of scattering caused by the first scattering S1 is greater than a second degree of scattering caused by the second scattering S2. The light extraction film 1 according to another embodiment may be provided in accordance with desired optical characteristics such that the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1.

According to an embodiment, in the light extraction film 1, when a first degree of scattering caused by the first scattering S1 is greater than a second degree of scattering caused by the second scattering S2, an average total transmittance of the substrate 101, i.e., the light extraction film 1, with respect to a wavelength of the light may be greater than or equal to 70%. In this case, the average total reflectance of the substrate 101 for the wavelength of the light may be less than 20%. The average total transmittance for the wavelength of the light may correspond to an average of the total integrated transmittance occurring when the wavelength of the light is changed. The average total reflectance for the wavelength of the light may correspond to an average of the total integrated reflectance occurring when the wavelength of the light is changed.

As described above, in the light extraction film 1, when the first degree of scattering caused by the first scattering S1 is greater than the second degree of scattering caused by the second scattering S2, the light extraction film 1 having high transparency and low reflectance can be obtained. In addition, in this case, an average haze (haze) value for the wavelength of light may be about greater than or equal to 80%, so that high haze may be exhibited and luminance variation according to a viewing angle may be minimized, thereby realizing Lambertian emission (Lambertian emission). In addition, a color coordinate variation according to a viewing angle can be minimized. In addition, when the light extraction film 1 is attached to a lighting device, light extraction efficiency of the lighting device may be improved, a uniform white lighting effect may be obtained by a user, and excellent power efficiency may be achieved.

According to another embodiment, in the light extraction film 1, when the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1, the average total transmittance of the substrate 101, i.e., the light extraction film 1, for the wavelength of the light may be less than 70%. In this case, the average total reflectance of the substrate 101 for the wavelength of the light may be greater than or equal to 20%.

As described above, in the light extraction film 1, when the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1, the transparency is relatively low and the reflectance is relatively high, but the average optical haze value for the wavelength of light may be about 80% or more, and thus high haze may be exhibited. Further, the luminance variation according to the viewing angle can be reduced, so an effect similar to lambertian emission can be obtained, and also the color coordinate variation according to the viewing angle can be reduced. Therefore, when the light extraction film 1 is attached to an illumination device, the light extraction efficiency of the illumination device can be improved, a user can obtain a uniform white illumination effect, and excellent power efficiency can be achieved.

When the first degree of scattering caused by the first scattering S1 is greater than the second degree of scattering caused by the second scattering S2, the optical haze value of the light extraction film 1 decreases to a first angle as the wavelength of the light increases, and when the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1, the optical haze value of the light extraction film 1 may decrease to a second angle as the wavelength of the light increases. In this case, the second angle may be greater than the first angle. Therefore, with respect to the average optical haze value according to the wavelength of light, the light extraction film when the first degree of scattering caused by the first scattering S1 is greater than the second degree of scattering caused by the second scattering S2 is larger, and the second degree of scattering caused by the second scattering S2 is larger than the light extraction film 1 when the first degree of scattering caused by the first scattering S1. That is, in consideration of haze of light, the light extraction film when the first degree of scattering caused by the first scattering S1 is greater than the second degree of scattering caused by the second scattering S2 may exhibit relatively excellent characteristics compared to the light extraction film 1 when the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1. However, as described above, the light extraction film 1 in which the first degree of scattering by the first scattering S1 is greater than the second degree of scattering by the second scattering S2 can also obtain an optical haze value sufficient for the illumination device, and thus, the luminance change and the color coordinate change according to the angle can be reduced, and thus the optical characteristics as the illumination device can be displayed.

In the light extraction film 1 according to an embodiment, the holes 102 each have a first diameter when the first degree of scattering caused by the first scattering S1 is greater than the second degree of scattering caused by the second scattering S2, and the holes 102 have a second diameter when the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1, in which case the first diameter may be greater than the second diameter.

In the light extraction film 1 according to another embodiment, when a first degree of scattering caused by the first scattering S1 is greater than a second degree of scattering caused by the second scattering S2, the surface roughness of at least one of the first face 11 and the second face 12 becomes a first roughness, and when a second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1, the surface roughness of at least one of the first face 11 and the second face 12 becomes a second roughness, in which case the second roughness may be greater than the first roughness.

When a first degree of scattering caused by the first scattering S1 is greater than a second degree of scattering caused by the second scattering S2, the aperture 102 may greatly affect the first scattering S1.

According to an embodiment, the holes 102 may each have a radius greater than or equal to 0.5 μm when a first degree of scattering caused by the first scattering S1 is greater than a second degree of scattering caused by the second scattering S2. In this case, the radius of the hole 102 may be based on the long axis. More specifically, the holes 102 may each have a radius greater than or equal to 1 μm.

Alternatively, the surface roughness of at least one of the first face 11 and the second face 12 may be less than or equal to 20nm in terms of root mean square (rms).

As described above, when the first degree of scattering caused by the first scattering S1 is greater than the second degree of scattering caused by the second scattering S2, the surface roughness of at least one of the first face 11 and the second face 12 may not have a great influence on the optical characteristics of the light extraction film 1. Therefore, in the light extraction film 1 according to an embodiment, when it is designed that the first degree of scattering caused by the first scattering S1 is greater than the second degree of scattering caused by the second scattering S2, the holes 102 may be designed to each have a radius greater than or equal to 0.5 μm.

In the light extraction film 1 according to another embodiment, when the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1, the surface roughness of at least one of the first face 11 and the second face 12 may have a great influence on the first scattering S1.

Optionally, when a first scattering degree caused by the first scattering S1 is greater than a second scattering degree caused by the second scattering S2, a surface roughness of at least one of the first face 11 and the second face 12 may be greater than or equal to 50nm in terms of root mean square.

Alternatively, the holes 102 may each have a radius of less than or equal to 1 μm. In particular, the holes 102 may each have a radius of less than or equal to 0.5 μm.

As described above, when the second degree of scattering caused by the second scattering S2 is larger than the first degree of scattering caused by the first scattering S1, the influence of the aperture 102 diameter on the optical characteristics of the light extraction film 1 is smaller compared to the foregoing embodiment.

Therefore, in the light extraction film 1 according to an embodiment, when it is designed that the second degree of scattering caused by the second scattering S2 is greater than the first degree of scattering caused by the first scattering S1, the surface roughness of at least one of the first face 11 and the second face 12 may be designed to be greater than or equal to 50nm in terms of root mean square.

The light extraction film 1 according to the above-described embodiment may have a single film shape as shown in fig. 1. But is not limited thereto, as shown in fig. 2, the light extraction film 1 according to another embodiment may further include a base 100 adjacent to the first face 11. The susceptor 100 may serve an auxiliary function for forming the base material 101 during the manufacturing process of the base material 101. The base 100 may be provided in the shape of a substrate and/or a film, may be provided to have rigidity (rigid) or flexibility, and may be provided with a glass material or a polymer material that is light-transmittable.

Fig. 3 is a sectional view schematically showing a two-side-emission lighting device 2 according to another embodiment.

As shown in fig. 3, a two-sided light emitting lighting device 2 according to an embodiment may include a first light emitting surface 201 and a second light emitting surface 202 which are oppositely provided, a light emitting device 20 located between the first light emitting surface 201 and the second light emitting surface 202, and a light extraction film 1 located at the first light emitting surface 201.

The light emitting device 20, which may be positioned between the opposing first and second light emitting faces 201, 202 and encapsulated, may emit first light L1 in a first direction D1 (i.e., the direction of the first light emitting face 201) and second light L2 in a second direction D2 (i.e., the direction of the second light emitting face 202).

Since the first light emitting surface 201 is opposite to the second light emitting surface 202, the first light L1 and the second light L2 can be emitted in opposite directions.

The light emitting device 20 may be a self-emitting device, and according to an embodiment, the light emitting device 20 may be an organic light emitting device. But not limited thereto, the light emitting device 20 may be an inorganic light emitting device, and various bi-directional light emitting devices such as various UV LEDs may be used.

The light extraction film 1 may be positioned on the first light emitting surface 201.

Accordingly, the first light L1 is diffused while transmitting the light extraction film 1, and thus the first light L1 may become the diffused third light L3. The third light L3 is obtained by diffusion of the first light L1, and thus its luminance may be improved compared to the first light L1.

The first light L1 may be reflected by the light extraction film 1, and the reflected first light L1 is reflected toward the second direction D2, thereby forming fourth light L4.

As described above, the transmittance and reflectance of the light extraction film 1 can be changed by adjusting the difference between the first degree of scattering caused by the first scattering and the second degree of scattering caused by the second scattering.

The light transmittance of the light extraction film 1 when a first degree of scattering caused by the first scattering is larger than a second degree of scattering caused by the second scattering is larger than the light transmittance of the light extraction film 1 when the second degree of scattering is larger than the first degree of scattering. In addition, the light reflectance of the light extraction film 1 in the case where a first degree of scattering due to the first scattering is larger than a second degree of scattering due to the second scattering, which is larger than the light reflectance of the light extraction film 1 at the time of the first degree of scattering, is smaller than that at the time of the second degree of scattering.

According to an embodiment, when the first degree of scattering is greater than the second degree of scattering, the light transmittance of the light extraction film 1 may be greater than or equal to 70%. When the second degree of scattering is greater than the first degree of scattering, the light extraction film 1 may have a light transmittance of less than 70%.

Therefore, the brightness of the third light L3 when the first degree of scattering is greater than the second degree of scattering may be higher than the brightness of the third light L3 when the second degree of scattering is greater than the first degree of scattering.

According to an embodiment, when the first degree of scattering is greater than the second degree of scattering, the light extraction film 1 may have a light reflectance of less than 20%. When the second degree of scattering is greater than the first degree of scattering, the light extraction film 1 may have a light reflectance of greater than or equal to 20%.

Therefore, the brightness of the fourth light L4 when the second degree of scattering is greater than the first degree of scattering may be higher than the brightness of the fourth light L4 when the first degree of scattering is greater than the second degree of scattering.

As described above, the brightness of light emitted from the light emitting device 20 to the first and second directions D1 and D2 may be adjusted by adjusting the first and second degrees of scattering of the light extraction film 1.

That is, when the light extraction film 1 in which the first degree of scattering is greater than the second degree of scattering is used, the luminance in the first direction D1 may be set to be greater than when the light extraction film 1 in which the second degree of scattering is greater than the first degree of scattering is used.

Alternatively, when the light extraction film 1 in which the second degree of scattering is larger than the first degree of scattering is used, the luminance in the second direction D2 may be set to be larger than when the light extraction film 1 in which the first degree of scattering is larger than the second degree of scattering is used.

In addition, the two-side light emitting illumination apparatus 2 as described above may be implemented as a transparent illumination apparatus of the external light transmitting light emitting device 20. In this case, the first light L1 and the third light L3 are emitted to the first direction D1, and the second light L2 and the fourth light L4 are emitted to the second direction D2, so that the bidirectional transparent lighting device can be implemented. Alternatively, when light is not emitted to the first direction D1 and/or the second direction D2, external light is transmitted through the light emitting device 20 so that a user can observe an opposite object. In addition, since the brightness in the first direction D1 and/or the second direction D2 may be set as described above, different lighting effects may be bidirectionally realized.

Fig. 4 is a sectional view showing a more specific embodiment of the two-side-emission lighting device 2 according to another embodiment.

According to the embodiment shown in fig. 4, an organic light emitting unit 24 may be used as the light emitting device 20. As shown in fig. 4, the two-sided light emitting lighting device 2 may include a substrate 21 and an encapsulation member 22 facing each other, and an organic light emitting unit 24 between the substrate 21 and the encapsulation member 22. The substrate 21 and the encapsulation part 22 may be combined with each other, and the organic light emitting unit 24 interposed between the substrate 21 and the encapsulation part 22 may be resisted from the external air and encapsulated. According to an embodiment shown in fig. 4, the encapsulation part 22 is provided in the shape of a substrate, which may be bonded to the substrate 21 via a sealant 23 at its edge. But not limited thereto, the encapsulation part 22 may include a thin film structure including at least one film, in which case the encapsulation part 22 may be formed on the substrate 21 to cover the organic light emitting unit 24.

According to the embodiment shown in fig. 4, the light emitted from the organic light emitting unit 24 may include first light L1 emitted toward the substrate 21 and second light L2 emitted toward the encapsulation part 22.

The light extraction film 1 according to the above-described embodiment may be bonded to the outer surface of the substrate 21. In this case, the light extraction film 1 may be positioned so that the above-described first face 11 faces the substrate 21.

The organic light emitting unit 24 may include an organic light emitting device emitting white light, and as shown in fig. 5, the organic light emitting unit 24 may include a first electrode 241 formed on a substrate 21, a second electrode 242 opposite to the first electrode 241, and an organic layer 243 interposed between the first electrode 241 and the second electrode 242.

The first electrode 241 and the second electrode 242 may serve as an Anode (Anode) and a Cathode (Cathode), respectively, and the polarities thereof may be opposite.

When the first electrode 241 functions as an anode, it is provided to include a conductor having a high work function, and when it functions as a cathode, it is provided to include a conductor having a low work function. When the second electrode 242 functions as a cathode, it is provided to include a conductor having a low work function, and when it functions as an anode, it is provided to include a conductor having a high work function. As a conductor having a high work function, a transparent conductive oxide such as Indium Tin Oxide (ITO), indium oxide (In2O3), zinc oxide (ZnO), Indium Zinc Oxide (IZO), or a noble metal such as gold (Au) can be used. As the conductor having a low work function, silver (Ag), aluminum (Al), magnesium (Mg), lithium (Li), calcium (Ca), lithium fluoride (LiF)/aluminum (Al), or the like may be used.

In the two-sided emission structure shown in fig. 5, the first electrode 241 and the second electrode 242 may be provided to include a light transmitter.

For this reason, when the first electrode 241 functions as an anode, the first electrode 241 may be formed by forming a film of indium tin oxide, indium zinc oxide, indium oxide, or the like having a high work function. In addition, when the first electrode 241 functions as a cathode, a thin semi-transmissive film may be formed using silver, aluminum, magnesium, lithium, calcium, lithium fluoride/aluminum, or the like, which has a small work function.

When the second electrode 242 serves as a cathode, a thin semi-transmissive film may be formed using a metal having a small work function, such as lithium, calcium, lithium fluoride/aluminum, magnesium, or silver. When the second electrode 242 serves as an anode, the second electrode 242 may be formed by forming a film of indium tin oxide, indium zinc oxide, indium oxide, or the like.

The organic layer 243 may include a first organic layer 2431 and a second organic layer 2432 and a light emitting layer 2433 interposed between the first organic layer 2431 and the second organic layer 2432.

The first and second organic layers 2431 and 2432 serve to facilitate the flow of holes and electrons from an anode and a cathode, and when the first electrode 241 is an anode, the first organic layer 2431 may include a hole injection/transport layer and/or an electron blocking layer, and the second organic layer 2432 may include an electron injection/transport layer and/or a hole blocking layer. In addition, when the first electrode 241 is a cathode, the first organic layer 2431 may include an electron injection/transport layer and/or a hole blocking layer, and the second organic layer 2432 may include a hole injection/transport layer and/or an electron blocking layer.

The light emitting layer 2433 may use a single organic compound material capable of emitting white light, and may be formed by stacking two or more organic light emitting layers of different colors.

When two or more organic light emitting layers of different colors are stacked to form the light emitting layer 2433, a red light emitting layer, a green light emitting layer, and a blue light emitting layer may be sequentially stacked, or a sky blue light emitting layer may be stacked on a mixed layer of red and green.

White light emission may be achieved by applying other various methods.

The organic light emitting unit 24 as described above may be provided with a plurality of kinds of pixels, but is not necessarily limited thereto, and the organic light emitting unit 24 may be provided with a surface emission type of a single pixel.

Further alternatively, in the organic light emitting unit 24, the interval between pixels may be provided to be transparent, whereby the organic light emitting unit 24 may function as a transparent member that can transmit light when not emitting light.

In the two-sided light emitting illumination device 2, as described above, the light extraction film 1 can not only improve the light extraction efficiency of the light emitted from the organic light emitting unit 24, but also can obtain a uniform white illumination effect and can also improve the power efficiency.

The two-sided light-emitting lighting device 2 can be manufactured by directly forming the base material 101 of the light extraction film 1 shown in fig. 1 on the surface thereof based on the substrate 21 or the package member 22. But is not limited thereto, the light extraction film 1 as shown in fig. 1 may be attached to the substrate 21 or the encapsulation member 22 by another adhesive member and/or a bonding method. In addition, the base 100 of the light extraction film 1 as shown in fig. 2 may be attached to the substrate 21 or the encapsulation member 22 by an additional adhesive member and/or a bonding method.

In the embodiment shown in fig. 4, the bottom surface of the substrate 21 may be the first light emitting surface 201, and the upper surface of the package component 22 may be the second light emitting surface 202, but the invention is not limited thereto, and the bottom surface of the substrate 21 may be the second light emitting surface 202, and the upper surface of the package component 22 may be the first light emitting surface 201.

More specific examples of the light extraction film 1 are as follows.

A coating composition solution is prepared.

According to an embodiment, the coating composition solution may include a colorless polyamic acid.

The coating composition solution may be prepared by: in DMAc solvent at a ratio of 1: 4,4'-oxydiphthalic anhydride (4,4' -oxydiphthalic anhydride) and 2,2-bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane (2,2-bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane) were mixed at a molar ratio of 1, stirred for 24 hours, and then diluted with 3 wt% DMAc solvent.

The coating composition solution is then coated on the base. The base may be the base 100 shown in fig. 2, but is not limited thereto, and the base may be the substrate 21 and/or the package member 22 shown in fig. 4.

The base coated with the coating composition solution as described above is carried into a solvent for forming pores.

The solvent for forming the pores may use Polar protic solvents (Polar protic solvents), which may include alcohols.

According to the first embodiment, 100% deionized Water (DIW, De-Ionized Water) is used as the solvent for forming the pores. According to the second embodiment, 100% ethanol is used as the solvent for forming the pores.

The first and second embodiments thus formed were subjected to a heat drying treatment at 170 ℃ to form the polyimide-based substrate 101.

Fig. 6 is a sectional SEM image a and a surface SEM image of the first embodiment, and fig. 7 is a sectional SEM image a and a surface SEM image b related to the second embodiment.

The thickness of the formed film (e.g., substrate) was 3.05 μm in the first embodiment and 1.28 μm in the second embodiment. As described above, the film thickness in the first embodiment is larger than that in the second embodiment for the films composed under the same conditions.

Of the formed pores, the maximum pore diameter (with respect to the long axis) was about 3 μm in the first embodiment, and about 1.3 μm in the second embodiment. It can be seen that the aperture of the first embodiment is significantly larger than that of the second embodiment.

The surface roughness (root mean square) was 3.6nm in the first example and 68nm in the second example. It can be seen that the surface roughness of the second embodiment is significantly greater than that of the first embodiment.

Fig. 8 shows the total transmittance of the wavelength band in the visible light region according to the first embodiment (a) and the second embodiment (B). As shown in fig. 8, the first embodiment (a) shows a higher total transmittance, and the second embodiment (B) shows a lower total transmittance.

According to a first embodiment (a), the average total transmission is about 74%. In this case, the average total reflectance in the first embodiment (a) is 15%.

According to a second embodiment (B), the average total transmission is about 59%. In this case, the average total reflectance in the second embodiment (B) is 26%.

Fig. 9 shows optical haze values in the visible light region according to the first embodiment (a) and the second embodiment (B).

As shown in fig. 9, the optical haze value according to the first embodiment (a) decreases at a gentle angle as the wavelength increases, while the optical haze value according to the second embodiment (B) decreases at the steepest angle as the wavelength increases. Therefore, the average total optical haze value in the second embodiment (B) is lower than that in the first embodiment (a). But in each case exhibited an average optical haze value of about 80% or greater.

The light extraction film thus formed is provided on the two-sided light emitting illumination device 2 as shown in fig. 3 and/or fig. 4. In the structure of FIG. 4, 700 μm glass was used as the substrate 21, 150nm indium tin oxide was used for the first electrode 241, and 20nm aluminum was used for the second electrode 242. The first organic layer 2431 has a stacked structure of 1.5nm molybdenum trioxide (MoO3) and 45nm CBP, and the second organic layer 2432 has a stacked structure of 20nm TPBi, 45nm Bphen, and 1.5nm cesium carbonate (Cs2CO 3). The light-emitting layer 2433 uses 15nm CBP: ir (ppy)2 (acac).

Fig. 10 is a graph showing a comparison of power efficiency when the first embodiment (a) and the second embodiment (B) are formed in the two-sided light emitting lighting device with the comparative example (ref). Comparative example (ref) did not use a light extraction film.

As shown in fig. 10, the first embodiment (a) and the second embodiment (B) have very high power efficiency as compared with the comparative example (ref).

Fig. 11 shows a comparison of External Quantum Efficiencies (EQEs) of the first embodiment (a) and the second embodiment (B) and the comparative example (ref). As shown in fig. 11, the first embodiment (a) and the second embodiment (B) have very high external quantum efficiency as compared with the comparative example (ref).

Fig. 12 shows changes in luminance of light in the first direction D1 occurring according to changes in current of the first and second embodiments (a) and (B) and the comparative example (ref). Fig. 13 shows changes in luminance of light in the second direction D2 occurring according to changes in current of the first and second embodiments (a) and (B) and the comparative example (ref).

As shown in fig. 12 and 13, both the first embodiment (a) and the second embodiment (B) showed very high luminance as compared with the comparative example (ref). In particular, in the second direction D2 where the light extraction film 1 is not attached, the first embodiment (a) and the second embodiment (B) also show higher luminance than the comparative example.

The first embodiment (a) has a higher luminance than the second embodiment (B) in the first direction D1, and the second embodiment (B) has a higher luminance than the first embodiment (a) in the second direction D2.

The above-described first embodiment (a) may correspond to the case when the first degree of scattering caused by the first scattering is larger than the second degree of scattering caused by the second scattering, as described above. Also, the second embodiment (B) may correspond to the case when the second degree of scattering by the second scattering S2 is greater than the first degree of scattering by the first scattering S1, as described above. As described above, although the first embodiment (a) has more excellent optical characteristics in the first direction D1, the second embodiment (B) can also have more excellent optical characteristics in the second direction D2, and thus when implementing a two-sided light emitting illumination device, the light emission luminance of both sides can be adjusted as needed.

While the invention has been described with reference to the embodiments shown in the drawings, the description is illustrative only, and it is to be understood that various modifications and equivalent other embodiments may be made in accordance with the invention. Therefore, the true technical scope of the present invention should be defined by the appended claims.

Industrial applicability

The present invention, as a bidirectional light-emitting illumination device, can be used for a transparent illumination device through which external light can be transmitted. In this case, the light emitting efficiency and the brightness adjustment in two directions can be realized, thereby further improving the illumination effect.