阅读说明：本技术 棱镜组件、发光装置和投影系统 (Prism assembly, light-emitting device and projection system ) 是由 方元戎 郭祖强 陈晨 于 2020-05-25 设计创作，主要内容包括：本申请公开了棱镜组件、发光装置和投影系统。棱镜组件中的棱镜包括入光面、与入光面相对的功能面以及设置在入光面与功能面之间的分光元件；其中,入射光经由入光面传递至分光元件,分光元件用于将至少部分入射光反射出于棱镜外。本申请使得入射光在棱镜中传播时角分布不改变,以减小分光元件的面积,减小扩展量的稀释,提高光源的效率。(The application discloses prism subassembly, illuminator and projection system. The prism in the prism assembly comprises a light incident surface, a functional surface opposite to the light incident surface and a light splitting element arranged between the light incident surface and the functional surface; the light splitting element is used for reflecting at least part of incident light out of the prism. The prism makes the incident light not change in angular distribution when propagating in the prism to reduce the area of light splitting component, reduce the dilution of extension, improve the efficiency of light source.)

1. A prism assembly is characterized in that the prism assembly comprises a prism, wherein the prism comprises a light incident surface, a functional surface opposite to the light incident surface and a light splitting element arranged between the light incident surface and the functional surface;

the light splitting element is used for reflecting at least part of the incident light out of the prism, and the rest of the incident light reaches the functional surface after transmitting the light splitting element.

2. The prism assembly of claim 1, wherein the prism assembly further comprises an optical processing element disposed on the functional face;

the light splitting element is used for reflecting part of the incident light out of the prism and transmitting the rest part of the incident light to form bypass light and irradiate the bypass light to the optical processing element; the bypass light is processed by the optical processing element and then returns to the light splitting element, and is reflected out of the prism by the light splitting element.

3. The prism assembly of claim 2, wherein the optical processing element comprises a mirror.

4. The prism assembly according to claim 2, wherein the beam splitting element is a polarization beam splitting element, and the polarization beam splitting element is configured to reflect incident light of a first polarization state, transmit incident light of a second polarization state to form the bypass light, and irradiate the bypass light to the optical processing element;

the optical processing element comprises a reflecting mirror and an 1/4 wave plate, the 1/4 wave plate is located between the reflecting mirror and the polarization beam splitting element, and the 1/4 wave plate and the reflecting mirror are matched for changing the polarization direction of the bypass light, so that the bypass light after changing the polarization direction can be reflected by the polarization beam splitting element to the outside of the prism.

5. The prism assembly according to claim 1,

the prism is including connecting go into the plain noodles with four sides of functional surface, four sides respectively with go into the plain noodles with the functional surface is perpendicular, and at least a set of relative side is parallel to each other.

6. A light-emitting device, comprising:

a light source for emitting excitation light;

the prism assembly comprises a prism, the prism comprises a light incident surface, a functional surface opposite to the light incident surface and a light splitting element arranged between the light incident surface and the functional surface, and the light source is arranged on one side of the light incident surface;

the wavelength conversion device is used for absorbing the exciting light and exciting to emit stimulated light which propagates to the prism;

the excitation light of the light source is transmitted to a light splitting element arranged in the prism through the light incident surface of the prism, the light splitting element is used for emitting at least part of the excitation light to the wavelength conversion device, and the rest excitation light reaches the functional surface after transmitting the light splitting element.

7. The light-emitting device according to claim 6, further comprising a light uniformizing device;

the light homogenizing device is arranged between the light source and the prism, and a light emitting surface of the light homogenizing device is tightly attached to a light incident surface of the prism; the area of the light incident surface of the prism is matched with the size of the emergent light spot of the light uniformizing device.

8. The light-emitting device according to claim 6, wherein the prism assembly further comprises an optical processing element disposed on the functional surface, the light-splitting element being located between the optical processing element and the light-incident surface;

the light splitting element is used for reflecting part of the exciting light to the wavelength conversion device and transmitting the rest part of the exciting light to form bypass light and irradiate the bypass light to the optical processing element; the bypass light returns to the light splitting element after being processed by the optical processing element, and is reflected by the light splitting element to form second emergent light.

9. The light-emitting device according to claim 8, wherein the light-splitting element is a polarization light-splitting element configured to reflect the excitation light of a first polarization state to the wavelength conversion device, transmit the excitation light of a second polarization state to form the bypass light, and irradiate the bypass light to the optical processing element;

the optical processing device comprises a reflecting mirror and an 1/4 wave plate, wherein the 1/4 wave plate is positioned between the reflecting mirror and the polarization light splitting element, and the 1/4 wave plate is matched with the reflecting mirror to change the polarization direction of the bypass light so that the bypass light after the polarization direction is changed can be reflected by the polarization light splitting element to form second emergent light.

10. A projection system comprising a prism assembly according to any of claims 1 to 5 and/or a light emitting device according to any of claims 6 to 9.

Technical Field

The present application relates to the field of light emitting device technology, and more particularly, to a prism assembly, a light emitting device and a projection system.

Background

At present, the application of laser light source has been paid more and more attention. The laser has the advantages of high brightness and long service life, but the spectrum of the laser is narrow, and meanwhile, the speckle effect of a projected image is obvious due to the high coherence of the laser, and the imaging quality is seriously influenced, so that the laser is often used for exciting a fluorescent material to form mixed luminescence in use.

In the prior art, due to the structural configuration of the light-emitting device, the distance of mixed light formed in the light-emitting device entering a subsequent optical system is long, the optical expansion is diluted, the energy cannot be completely utilized by an optical machine, and finally the efficiency of a light source is low.

Disclosure of Invention

The application provides prism subassembly, illuminator and projection system for the angular distribution does not change when the incident light propagates in the prism, with the area that reduces light splitting component, reduces the dilution of extension, improves the efficiency of light source.

In order to solve the above-mentioned object, the present application provides a prism assembly, which includes a prism, the prism includes a light incident surface, a functional surface opposite to the light incident surface, and a light splitting element disposed between the light incident surface and the functional surface;

the light splitting element is used for reflecting at least part of incident light out of the prism, and the rest of the incident light reaches the functional surface after transmitting the light splitting element.

Wherein the prism assembly further comprises an optical processing element arranged on the functional surface;

the light splitting element is used for reflecting part of incident light out of the prism, transmitting the rest part of the incident light to form bypass light and irradiating the bypass light to the optical processing element; the bypass light is processed by the optical processing element and then returns to the light splitting element, and is reflected out of the prism by the light splitting element.

Wherein the optical processing element comprises a mirror.

The light splitting element is a polarization light splitting element, and the polarization light splitting element is used for reflecting incident light in a first polarization state, transmitting incident light in a second polarization state to form the bypass light and irradiating the bypass light to the optical processing element;

the optical processing element comprises a reflecting mirror and an 1/4 wave plate, the 1/4 wave plate is positioned between the reflecting mirror and the polarization beam splitting element, and the 1/4 wave plate and the reflecting mirror are matched for changing the polarization direction of the bypass light, so that the bypass light after changing the polarization direction can be reflected out of the prism by the polarization beam splitting element.

The prism comprises four side faces connected with the light incident face and the functional face, the four side faces are perpendicular to the light incident face and the functional face respectively, and at least one group of opposite side faces are parallel to each other.

To solve the above-mentioned object, the present application provides a light-emitting device, which includes a light source, a prism assembly and a wavelength conversion device;

the light source is used for emitting exciting light;

the prism assembly comprises a prism, the prism comprises a light inlet surface, a functional surface opposite to the light inlet surface and a light splitting element arranged between the light inlet surface and the functional surface, and a light source is arranged on one side of the light inlet surface of the prism;

the wavelength conversion device is used for absorbing the exciting light and stimulated to emit excited light which is transmitted to the prism;

the exciting light of the light source is transmitted to the light splitting element arranged in the prism through the light incident surface of the prism, the light splitting element is used for emitting at least part of the exciting light to the wavelength conversion device, and the rest exciting light reaches the functional surface after transmitting the light splitting element.

Wherein, the light-emitting device also comprises a light uniformizing device;

the light homogenizing device is arranged between the light source and the prism, and a light emitting surface of the light homogenizing device is tightly attached to a light incident surface of the prism; the area of the light incident surface of the prism is matched with the size of the emergent light spot of the light uniformizing device.

The prism assembly also comprises an optical processing element arranged on the functional surface, and the light splitting element is positioned between the optical processing device and the light incident surface;

the light splitting element is used for reflecting part of the exciting light to the wavelength conversion device, transmitting the rest part of the exciting light to form bypass light and irradiating the bypass light to the optical processing element; the bypass light is processed by the optical processing element and then returns to the light splitting element, and is reflected by the light splitting element to form second emergent light.

The wavelength conversion device comprises a wavelength conversion device, a light splitting element, a prism, a light splitting element and an optical processing element, wherein the light splitting element is a polarization light splitting element, the polarization light splitting element is used for reflecting exciting light in a first polarization state to at least partially emergent light of the wavelength conversion device to vertically irradiate one side surface of the prism, the emergent light is emitted out through the other side surface of the prism, which is parallel and opposite to the side surface, and the exciting light in a second polarization state is transmitted to form bypass light and irradiates the optical processing element;

the optical processing device comprises a reflecting mirror and an 1/4 wave plate, wherein the 1/4 wave plate is positioned between the reflecting mirror and the polarization beam splitting element, and the 1/4 wave plate and the reflecting mirror are matched for changing the polarization direction of the bypass light, so that the bypass light after the polarization direction is changed can be reflected by the polarization beam splitting element to form second emergent light.

At least part of emergent light of the wavelength conversion device perpendicularly enters one side face of the prism and is emitted out through the other side face of the prism, wherein the other side face is parallel to and opposite to the side face.

To solve the above-mentioned object, the present application provides a projection system, which includes the above-mentioned prism assembly and/or the above-mentioned light-emitting device.

Incident light transmits to the spectral component who sets up between income plain noodles and functional surface via the income plain noodles of prism in this application, and the angular distribution can not change when the incident light propagates in the prism, can reduce spectral component's area to reduce the dilution of expansion volume, improve light source efficiency.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic view of the construction of a prism assembly of the present application;

FIG. 2 is a schematic structural diagram of an embodiment of the prism assembly of the present application;

FIG. 3 is a schematic structural diagram of a light-emitting device according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of an embodiment of a wavelength conversion device in a light emitting device according to the present application;

fig. 5 is a schematic structural diagram of another embodiment of a light-emitting device according to the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In one aspect, the present application provides a prism assembly. Referring to fig. 1, the prism 12 of the prism assembly 10 includes an incident surface 121 and a functional surface 122. The functional surface 122 is opposite to the light incident surface 121. The light splitting element 13 is disposed between the light incident surface 121 and the functional surface 122, the incident light is transmitted to the light splitting element 13 through the light incident surface 121, and the light splitting element 13 is configured to reflect at least part of the incident light out of the prism 12. Specifically, the prism 12 may further be provided with an inclined surface inside, and the entire inclined surface is coated with a light splitting film to form the light splitting element 13. Alternatively, the inclined surface may be disposed at an inclination of 45 °. Of course, the setting angle of the inclined surface is not limited to this, and for example, the inclined surface may be set at an inclination angle of 30 °.

Alternatively, the light splitting element 13 may be a polarization light splitting element. The polarization beam splitting element may have polarization beam splitting characteristics only for light with the same polarization state as the incident light, so that light with a different emission color or polarization state from the incident light is prevented from being polarized and split by the beam splitting element 13, and it is avoided that light with a different emission color or polarization state from the incident light cannot completely penetrate through the beam splitting element 13.

Alternatively, the light splitting element 13 may be a wavelength splitting element. The wavelength splitting element may have a wavelength splitting characteristic only for light having the same emission color or emission wavelength as the incident light, so as to prevent light having a color different from the emission color or emission wavelength of the incident light from being wavelength-split by the light splitting element 13, and prevent light having a color different from the emission color or emission wavelength of the incident light from being transmitted through the light splitting element 13. For example, the light splitting element 13 may be a reflective sheet. The reflective sheet may have a reflective spectroscopic property only for light having the same emission color or emission wavelength as the incident light, so as to prevent light having a different emission color or emission wavelength from passing through the spectroscopic element 13.

The prism assembly 10 of the present application can further include an optical processing element 17. The light splitting element 13 may be configured to reflect a portion of the incident light out of the prism 12 and transmit the remaining portion of the incident light to form bypass light and irradiate the bypass light to the optical processing element 17. The optical processing element 17 is used for processing the bypass light, returning to the light splitting element 13, and reflecting the bypass light out of the prism 12 through the light splitting element 13.

The optical processing element 17 is disposed on the functional surface of the prism 12. And the light splitting element 13 is located between the optical processing element 17 and the light entry surface. Thus, the light splitting element 13 reflects part of the incident light out of the prism 12, and transmits the rest of the incident light to form bypass light to irradiate the bypass light to the optical processing element 17, and the optical processing element 17 can process the bypass light, return the bypass light to the light splitting element 13, and reflect the bypass light out of the prism 12 through the light splitting element 13.

In order to make full use of the incident light transmitted through the spectroscopic element 13, the arrangement of the optical processing element 17 can be appropriately adjusted based on the spectroscopic principle of the spectroscopic element 13.

In one implementation, the light splitting element 13 is a polarization light splitting element, and since there may be a problem of impurities in the polarization state of the incident light, part of the incident light may pass through the light splitting element 13, resulting in light energy loss and reduced light source efficiency. The optical processing element 17 can change the polarization state of the incident light transmitted through the light splitting element 13, so that the light with the changed polarization state can be reflected by the light splitting element 13, and the light source efficiency is improved. Specifically, as shown in fig. 2, the optical processing element 17 in this embodiment may include a mirror 171 and an 1/4 wave plate 172, the 1/4 wave plate 172 is located between the mirror 171 and the light splitting element 13, and the 1/4 wave plate 172 and the mirror 171 cooperate to change the polarization direction of the bypass light, so that the bypass light after changing the polarization direction can be reflected by the light splitting element 13 out of the prism 12.

The light splitting element 13 may be a reverse p-transmission s-polarization light splitting element or a reverse s-transmission p-polarization light splitting element.

Illustratively, the incident light is blue light, the light splitting element 13 is a reverse s-polarized blue light-p-polarized blue light-transmitting light splitting element, the p blue light is converted into circularly polarized light when passing through the 1/4 wave plate 172 for the first time, and the circularly polarized light passes through the 1/4 wave plate 172 again after being reflected by the reflecting mirror 171, at this time, the circularly polarized light is converted into s blue light and enters the light splitting element 13 along the original light path, and is reflected outside the prism 12 by the light splitting element 13, so that the p blue light transmitted from the light splitting element 13 can be converted into s blue light and returns to the light splitting element 13, so as to fully utilize the p blue light transmitted from the light splitting element 13.

When the spectroscopic element 13 is a polarization spectroscopic element, the polarization direction of most of the incident light is the same as the polarization direction of the light reflected by the spectroscopic element 13 in order to ensure that the spectroscopic element 13 reflects at least most of the incident light outside the prism 12. For example, the incident light is at least mostly s-light, and the spectroscopic element 13 is capable of reflecting s-incident light and transmitting p-incident light.

In another implementation, the light splitting element 13 is a wavelength light splitting element, and further, the light splitting element 13 may be a reflective sheet. The optical processing element 17 may comprise only the mirror 171. Thus, the mirror 171 can reflect the bypass light to the light splitting element 13, and the light splitting element 13 can reflect at least part of the bypass light outside the prism 12, so that the excitation light transmitted through the light splitting element 13 can be fully utilized, and the configuration of the optical processing element 17 is very simple.

Wherein, the reflectivity of the reflector plate can be adjusted according to requirements. Alternatively, the reflective sheet has a reflectance of 50%, 60%, 70%, 80%, or 90%, etc.

In short, in the present embodiment, the incident light is transmitted to the light splitting element 13 provided between the light incident surface 121 and the functional surface 122 via the light incident surface of the prism 12, and the angular distribution of the incident light is not changed when the incident light propagates through the prism 12, so that the area of the light splitting element 13 can be reduced, thereby reducing the dilution of the spread and improving the light source efficiency.

In addition, the prism 12 may further include a side surface connecting the light incident surface 121 and the functional surface 122. The light incident surface 121, the functional surface 122, and the side surface of the prism 12 may be optical planes.

Wherein the number of sides can be adjusted to the specific situation. Preferably, prism 12 includes at least four sides. More preferably, prism 12 includes four sides. Most preferably, the prism 12 is rectangular parallelepiped.

Wherein at least one set of opposing sides are parallel to each other. Therefore, light perpendicularly enters one side face of the prism 12 and can perpendicularly exit from the other side face of the prism 12, which is parallel to and opposite to the side face, so that the distance of light propagating in the prism 12 is as consistent as possible, the uniformity of the light propagating through the prism 12 can be improved, and meanwhile, the vertical exit does not cause further increase of optical expansion, and the collection and utilization of light beams by subsequent optical elements are facilitated. More preferably, all sets of opposing sides are parallel to each other.

Alternatively, two adjacent side surfaces may also be perpendicular to each other.

And the side surface can be respectively vertical to the light incident surface and the functional surface.

In another aspect, the present application provides a light emitting device. As shown in fig. 3, the light emitting device 1 includes a light source 11, the prism assembly 10 of the above embodiment, and a wavelength conversion device 14. The light source 11 is used to emit excitation light. The light source 11 is disposed on the light incident surface side of the prism 12. A beam splitter 13 is provided in the prism 12. The excitation light of the light source 11 is transmitted to the light splitting element 13 disposed in the prism 12 through the light incident surface of the prism 12, the light splitting element 13 is configured to emit at least part of the excitation light to the wavelength conversion device 14, and the wavelength conversion device 14 is configured to absorb the excitation light and is excited to emit stimulated light which propagates toward the prism 12.

The light source 11 is used to emit excitation light. The light source 11 may be a laser light source including one emission color. The excitation light emitted from the light source 11 is absorbed and excited by the wavelength conversion device 14 to generate excited light, and the excitation light and the excited light combine to form a first emergent light. The excited light may include at least two colors of light or a composite light of at least two colors of light, so that the excited light and the excitation light may combine to form white emergent light.

For example, the light source 11 may be a blue laser light source array composed of several blue lasers, the blue excitation light is absorbed by the wavelength conversion device 14 and excited to generate green excitation light and red excited light, and the green excitation light, the red excited light and the blue excitation light may be combined to form white emission light. It is to be understood that the light source 11 may not be limited to the blue light source, but may be a violet light source, a red light source, a green light source, or the like.

In this embodiment, the excitation light emitted by the light source 11 is transmitted to the light splitting element 13 arranged in the middle of the prism 12 through the light incident surface of the prism 12, the angular distribution of the excitation light is not changed when the excitation light propagates in the prism 12, and the area of the light splitting element 13 can be reduced, so that the distance of the excited light entering the subsequent optical system is reduced, the dilution of the expansion amount is reduced, and the light source efficiency is improved.

Specifically, the prism 12 may be provided with a slope in the middle, and the entire slope is coated with a light splitting film to form the light splitting element 13. Alternatively, the inclined surface may be disposed at an inclination of 45 °. Of course, the setting angle of the slope is not limited to this, and may be determined specifically according to the setting positions of the light source 11 and the wavelength conversion device 14.

Alternatively, the light splitting element 13 may be a polarization light splitting element. The polarization beam splitter is used for reflecting the excitation light in the first polarization state to the wavelength conversion device, transmitting the excitation light in the second polarization state to form the bypass light and irradiating the bypass light to the optical processing element, so that the situation that the received laser light is polarized and split by the beam splitter 13 to cause that the received laser light cannot completely transmit through the beam splitter 13 is prevented.

Alternatively, the light splitting element 13 may be a wavelength splitting element. The wavelength splitting element may have wavelength splitting characteristics only for light of the same emission color or emission wavelength as the excitation light, so as to prevent the received laser light from being wavelength-split by the light splitting element 13 and being unable to transmit all the received laser light through the light splitting element 13. For example, in other implementations, the light splitting element 13 may be a reflective sheet. The reflection sheet may have a reflection spectroscopic characteristic only for light of the same emission color or emission wavelength as that of the excitation light, so as to prevent the stimulated light from being reflected and dispersed by the spectroscopic element 13 and being unable to transmit all the stimulated light through the spectroscopic element 13.

The light splitting element 13 is used to reflect at least part of the excitation light to the wavelength conversion device 14.

The wavelength conversion device 14 absorbs the excitation light and generates stimulated light that propagates toward the prism 12.

The wavelength conversion device 14 may be circular, square, or other shapes, without limitation. The present embodiment is described by taking a circular shape as an example.

The wavelength conversion device 14 may include a conversion region, a non-conversion region, and a driving device disposed at the bottom of the wavelength conversion device 14. The conversion regions and the non-conversion regions are alternately positioned on the light path of the excitation light emitted by the light source 11 under the action of the driving unit.

The conversion area and the non-conversion area can be respectively positioned in partial areas of the same circular ring and are spliced with each other to form a circular ring with a through hole in the center.

The switching and non-switching regions may be continuously provided or intermittently provided.

In order to make the conversion region capable of absorbing the excitation light and exciting to generate stimulated light, at least one wavelength conversion material may be disposed on the conversion region to generate stimulated light of at least one color under excitation of the excitation light.

The wavelength conversion material can be fluorescent powder, quantum dot material and phosphorescent material.

In addition, the emission color of the wavelength conversion material may be set according to the color of the excitation light, so that the excitation light and the excited light of at least one color emitted by the wavelength conversion device 14 may be combined to form white emission light.

For example, when the color of the excitation light is blue, the emission color of the wavelength conversion material is yellow-green. Alternatively, when the color of the excitation light is blue, the emission color of the wavelength conversion material is red and green. It is understood that the emission color of the wavelength converting material may be other colors besides red and green, yellow-green, and is not limited herein.

It will be appreciated that for ease of providing the wavelength converting device 14, where the number of emission colors of the wavelength converting material is at least two, the conversion region may be divided into at least two sub-conversion regions, with each wavelength converting material being provided on each sub-conversion region in a one-to-one correspondence. For example, the wavelength converting material disposed on the wavelength converting device 14 includes a red wavelength converting material and a green wavelength converting material, the conversion region is also divided into a first sub-conversion region on which the red wavelength converting material is disposed and a second sub-conversion region on which the green wavelength converting material is disposed, respectively.

Wherein the sub-conversion regions may be continuously disposed or may be discontinuously disposed.

In addition, the areas of the different sub-conversion regions may be equal, or may not be equal.

In this embodiment, the wavelength conversion device 14 has a circular cross section, as shown in fig. 4, the first sub-conversion region 141, the second sub-conversion region 142 and the non-conversion region 143 are circular arc regions continuously distributed, the center of each circular arc region is the rotation center of the wavelength conversion device 14, and the sum of the central angular radii of the first sub-conversion region 141, the second sub-conversion region 142 and the non-conversion region 143 is 360 degrees.

Further, in order to improve the uniformity of the light spot incident on the light incident surface of the prism 12, the light emitting device 1 may further include a light uniformizing device 16 disposed between the light source 11 and the prism 12. The light unifying means 16 is used to shape the angular distribution of the excitation light emitted by the light source 11 to produce a uniformly distributed spot. Optionally, the light homogenizing device 16 is a compound eye or a light homogenizing rod, but not limited thereto.

Further, the light-emitting surface of the light uniformizing device 16 is attached to the light-entering surface of the prism 12, or is directly attached to the light-entering surface of the prism 12, and the area of the light-entering surface of the prism 12 is matched with the size of the light spot emitted by the light uniformizing device 16, so that the area of the light splitting element 13 in the prism 12 can be minimized, the distance of the first emergent light entering the subsequent optical system can be further reduced, the amount of light reflected by the light splitting element 13 when the first emergent light passes through the prism 12 can be reduced, and the light source efficiency can be further improved.

The inventor of the present application finds that, when the first outgoing light reaches the light splitting element 13 region, the excited light and a part of the excited light transmit through the light splitting element 13, and the other part of the excited light is reflected by the light splitting element 13, so that a part of the excited light cannot transmit through the light splitting element 13, and the color of the outgoing light leaving the light splitting element 13 region does not match the preset color, that is, the first outgoing light leaving the light splitting element 13 region has a non-uniform color phenomenon. For example, when the excitation light is blue light, a part of the blue light cannot pass through the light splitting element 13, and the emission color of the first emission light leaving the region of the light splitting element 13 is yellowish. When the first outgoing light reaches the region other than the light splitting element 13, both the excited light and the excitation light can pass through and are not reflected. Because only the region of the light splitting element 13 reflects a part of the excitation light due to the action of the light splitting element 13, the emission colors of the first outgoing light respectively leaving from the region of the light splitting element 13 and the region outside the light splitting element 13 are not consistent, so that the first outgoing light leaving from the region of the prism 12 has a phenomenon of uneven color, and further, the color of the finally projected picture is uneven.

In order to solve the problem of uneven color of the first emergent light leaving the prism 12 area, the prism assembly of the present application further includes an optical processing element 17, the optical processing element 17 is used for processing the exciting light emitted from the light source 11 and penetrating through the light splitting element 13 and returning to the light splitting element 13, so that the light splitting element 13 reflects the part of light and forms a second emergent light, the first emergent light can be combined with the second emergent light for emitting, the exciting light penetrating through the light splitting element 13 can be utilized, the problem of uneven color of the light emitted by the light emitting device 1 can be weakened through the second emergent light, and the light source efficiency is improved.

The optical processing element 17 is disposed on the functional surface of the prism 12. And the light splitting element 13 is located between the optical processing element 17 and the light entry surface. Thus, when the light splitting element 13 reflects part of the excitation light to the wavelength conversion device 14, and transmits the remaining part of the excitation light to form bypass light to irradiate the optical processing element 17, the optical processing element 17 can process the bypass light and then return the bypass light to the light splitting element 13, and the bypass light is reflected by the light splitting element 13 to form second emergent light, so as to reduce the problem of non-uniform color of light emitted by the light emitting device 1 and improve the efficiency of the light source.

In order to make full use of the excitation light transmitted through the spectroscopic element 13, the arrangement of the optical processing element 17 can be appropriately adjusted based on the spectroscopic principle of the spectroscopic element 13.

In another implementation of the present application, the light splitting element 13 is a polarization light splitting element, and since there may be a problem that the polarization state of the excitation light emitted from the light source 11 is not pure, part of the excitation light may pass through the light splitting element 13, which causes a loss of light energy and a decrease in light source efficiency. The optical processing element 17 can change the polarization state of the excitation light transmitted through the light splitting element 13, so that the light with the changed polarization state can be reflected by the light splitting element 13 to form second emergent light, and the light source efficiency is improved. Specifically, as shown in fig. 5, the optical processing element 17 may include a mirror 171 and an 1/4 wave plate 172, the 1/4 wave plate 172 is located between the mirror 171 and the light splitting element 13, and the 1/4 wave plate 172 and the mirror 171 cooperate to change the polarization direction of the bypass light, so that the bypass light after changing the polarization direction can be reflected by the light splitting element 13 to form the second outgoing light.

The light splitting element 13 may be a reverse p-excitation light transmission s-excitation light polarization light splitting element or a reverse s-excitation light transmission p-excitation light polarization light splitting element.

Illustratively, the excitation light is blue light, the light splitting element 13 is a reverse s-polarized blue light-p-polarized blue light-transmitting light splitting element, the p blue light is converted into circularly polarized light when passing through the 1/4 wave plate 172 for the first time, and the circularly polarized light passes through the 1/4 wave plate 172 again after being reflected by the reflecting mirror 171, at this time, the circularly polarized light is converted into s blue light and enters the light splitting element 13 along the original light path, and is reflected by the light splitting element 13 to form second outgoing light, so that the p blue light transmitted from the light splitting element 13 can be converted into s blue light and returns to the light splitting element 13, so as to fully utilize the p blue light transmitted from the light splitting element 13.

In addition, when the spectroscopic element 13 is a polarization spectroscopic element, in order to ensure that the spectroscopic element 13 reflects at least most of the excitation light emitted from the light source 11 to the wavelength conversion device 14, the polarization direction of most of the excitation light emitted from the light source 11 is the same as the polarization direction of the light reflected by the spectroscopic element 13. For example, the excitation light emitted from the light source 11 is at least mostly s-light, and the spectroscopic element 13 is capable of reflecting the s-excitation light and transmitting the p-excitation light.

In another implementation, the light splitting element 13 is a wavelength light splitting element, and further, the light splitting element 13 may be a reflective sheet. The optical processing element 17 may comprise only the mirror 171. The mirror 171 can reflect the bypass light to the light splitting element 13, and the light splitting element 13 can reflect at least part of the bypass light to form second outgoing light, so that the excitation light transmitted through the light splitting element 13 can be fully utilized, and the configuration of the optical processing element 17 is very simple.

Wherein, the reflectivity of the reflector plate can be adjusted according to requirements. Alternatively, the reflective sheet has a reflectance of 50%, 60%, 70%, 80%, or 90%, etc.

Further, the light emitting device 1 may further include a first collecting device 18 located between the light uniformizing device 16 and the light source 11, the first collecting device 18 is configured to collect the excitation light and then inject the collected excitation light into the light uniformizing device 16, so that the size of the light spot may be reduced, the area of the light splitting element 13 may be further reduced, the distance of the first emission light entering the subsequent optical system may be reduced, and the efficiency of the light source may be improved. Alternatively, the first collection device 18 may be a positive or negative lens group.

In addition, the light emitting device 1 may further include a second collecting device 19 located between the light splitting element 13 and the wavelength conversion device 14, and configured to form an image on the wavelength conversion device 14 after the excitation light reflected by the light splitting element 13 is subjected to a surface angle change, and then converge the first emitting light formed by the wavelength conversion device 14 to emit the first emitting light.

Alternatively, the second collecting means 19 may be a collecting lens. The second collecting device 19 can be tightly attached to the side surface of the prism 12, and because the area of the light splitting element 13 is relatively small, the distance of the light emitted by the second collecting device 19 entering the subsequent optical system is reduced, so that the light spot entering the subsequent optical system is reduced, the solid angle size at the position of the panel is reduced, and the over-lens efficiency of the system is improved.

In addition, the light emitted from the second collecting device 19 can be vertically incident on one side surface of the prism 12 and emitted from the other side surface of the prism 12; and one side surface of the prism 12 and the other side surface of the prism 12 are parallel to each other, so that the distance traveled by the light emitted from the second collecting device 19 in the prism 12 can be as uniform as possible, resulting in higher uniformity of the light emitted from the light emitting device 1.

The above is an embodiment of the light emitting device 1 provided in the present application, and the present application further provides a projection system, where the projection system includes the light emitting device 1, and the light emitting device 1 is the light emitting device 1 provided in any one of the above embodiments, and has corresponding technical features and technical effects, which are not described herein again.

In summary, the excitation light emitted by the light source 11 is transmitted to the light splitting element 13 disposed in the middle of the prism 12 through the light incident surface of the prism 12, the light splitting element 13 reflects at least part of the excitation light to the wavelength conversion device 14, the wavelength conversion device 14 absorbs the excitation light and generates the stimulated light propagating toward the prism 12, the angular distribution of the excitation light does not change when propagating in the prism 12, the area of the light splitting element 13 can be reduced, and thus the distance from the stimulated light to the subsequent optical system is reduced, the dilution of the expansion amount is reduced, and the light source efficiency is improved.

The above embodiments are merely examples and are not intended to limit the scope of the present disclosure, and all modifications, equivalents, and flow charts using the contents of the specification and drawings of the present disclosure or those directly or indirectly applied to other related technical fields are intended to be included in the scope of the present disclosure.