CN111999973B

CN111999973B - Light conversion element, light source system and display device

Info

Publication number: CN111999973B
Application number: CN202010901222.6A
Authority: CN
Inventors: 胡飞; 郭祖强; 李屹
Original assignee: Appotronics Corp Ltd
Current assignee: Shenzhen Appotronics Corp Ltd
Priority date: 2017-01-22
Filing date: 2017-01-22
Publication date: 2022-04-26
Anticipated expiration: 2037-01-22
Also published as: WO2018133328A1; CN111999973A; CN108345161A; CN108345161B

Abstract

The invention discloses a light conversion element, a light source system and a display device. The light conversion element comprises an incident region, a light emitting unit, a reflection region, a light emitting region and a light recycling region, wherein the incident region, the light emitting unit, the reflection region and the light emitting region enclose to form a space structure, and the reflection region is arranged around the light emitting unit, wherein: the incidence area is used for incidence of exciting light; the light emitting unit is used for receiving incident exciting light to generate stimulated light; the reflection region is used for reflecting at least part of the stimulated light to the light-emitting region and reflecting the exciting light which is not absorbed by the light-emitting unit to the light-emitting unit; the light emitting area is used for emitting at least part of the received laser light; the light recycling area is used for reflecting the excitation light and/or the stimulated light which is incident to the light recycling area. Through the mode, the invention can reduce the volume of a product, reduce the cost and simultaneously improve the utilization rate of light so as to realize high-brightness display.

Description

Light conversion element, light source system and display device

The present application is a divisional application based on a patent application having an application number of 201710053442.6 and an invention name of "one kind of light conversion element, light source system, and display device" filed on application date of 2017, 1, month 22.

Technical Field

The present invention relates to the field of display technologies, and in particular, to a light conversion device, a light source system, and a display apparatus.

Background

In addition to using a bulb and pure laser as a light source, there is also a popular and popular light source technology in the existing projection light source: the exciting light is adopted to excite the rotating fluorescent powder color wheel or excite the fixed fluorescent powder sheet so as to generate time sequence light or emit white light.

In the above technology, the laser excited rotating color wheel or the laser excited fluorescent powder technology for exciting the fixed fluorescent powder sheet has improved brightness compared with the existing LED solid-state light source or bulb, and has lower cost and better image display effect compared with a pure laser light source. With the improvement of display requirements, the laser excited fluorescent powder technology also encounters unprecedented problems, and on one hand, when the light source is used for portable equipment such as micro-projection equipment, the problem of large volume cannot be overcome; on the other hand, the light efficiency of the light source is not high enough, if the light efficiency is further improved, new components are required to be added, so that the volume and the cost of the light source are increased; furthermore, this is a great challenge to the lifetime of solid-state light sources by increasing the current or voltage without adding new components.

Disclosure of Invention

The present invention provides a light conversion device, a light source system and a display device, which can reduce the volume of the product, reduce the cost, and improve the utilization rate of light to realize high-brightness display.

In order to solve the technical problems, the invention adopts a technical scheme that: providing a light conversion element, which comprises an incident area, a light emitting unit, a reflection area, a light emitting area and a light recycling area, wherein the incident area, the light emitting unit, the reflection area and the light emitting area enclose to form a space structure, and the reflection area is arranged around the light emitting unit; wherein:

the incidence area is used for incidence of exciting light;

the light emitting unit is used for receiving incident exciting light to generate stimulated light;

the reflecting region is used for reflecting at least part of the stimulated light to the light emitting region and reflecting the exciting light which is not absorbed by the light emitting unit to the light emitting unit;

the light emitting area is used for emitting at least part of the receiving laser;

the light recycling area is used for reflecting the excitation light and/or the stimulated light which is incident to the light recycling area.

And a dichroic element is arranged on the incident area and used for selectively transmitting the exciting light and reflecting the stimulated light.

Wherein, the length-width ratio of the light-emitting area is matched with the length-width ratio of the projection screen.

Wherein the aspect ratio of the light-emitting region is 4: 3 or 16: 9.

the light-emitting area is square, the light-emitting area and the light recovery area are located on the same plane, and the light recovery area is connected with the edge of the light-emitting area.

The light-emitting area is a spherical crown surface or a paraboloid, and the light recovery area is arranged along the circumferential direction of the light-emitting area;

wherein the light conversion element further comprises:

and a light exit lens provided on one side of the light exit region, for condensing the exit light emitted from the light exit region.

The light recovery area is a spherical crown surface or a paraboloid, and the incident area, the light emitting unit and the light emitting area of the light conversion element are positioned at the center of the spherical crown surface or the focus position of the paraboloid;

and a light transmitting area is arranged on the light recovery area.

Wherein, the light-emitting unit adopts pure-phase fluorescent ceramic or composite ceramic material.

In order to solve the technical problem, the invention adopts another technical scheme that: there is provided a light source system comprising:

a light source for emitting excitation light;

the dodging element is used for dodging the exciting light;

the light conversion element is used for receiving the excitation light after dodging and generating stimulated light, and comprises the light conversion element;

and the collecting element is used for receiving the excited light emitted by the light conversion element.

Wherein, the light source system still includes:

the heat dissipation piece is used for dissipating heat of the light source.

In order to solve the technical problem, the invention adopts another technical scheme that: there is provided a display device comprising a light source system as described in the foregoing.

The invention has the beneficial effects that: the present invention provides a light conversion device, a light source system and a display apparatus, wherein the light conversion device includes an incident region, a light emitting unit, a reflective region, a light emitting region and a light recycling region, the incident region, the light emitting unit, the reflective region and the light emitting region form a space structure, and the reflective region is disposed around the light emitting unit. The light recovery area is used for reflecting the excitation light and/or the stimulated light incident to the light recovery area. Therefore, the invention can reduce the volume of the product, reduce the cost and simultaneously improve the utilization rate of light so as to realize high-brightness display.

Drawings

Fig. 1 is a schematic structural diagram of a light source system according to an embodiment of the present invention;

FIG. 2 is a schematic view of a light source and a heat sink;

fig. 3 is a schematic structural diagram of a light conversion element according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another light conversion element provided in the embodiment of the present invention;

fig. 5 is a schematic structural diagram of another light conversion element provided in an embodiment of the present invention;

fig. 6 is a schematic structural diagram of another light conversion element provided in an embodiment of the present invention;

fig. 7 is an optical path diagram of a light conversion element provided in an embodiment of the present invention.

Detailed Description

Referring to fig. 1, fig. 1 is a schematic structural diagram of a light source system according to an embodiment of the present invention. As shown in fig. 1, the light source system 10 of the present embodiment includes a heat sink 1, a light source 2, a light uniformizing element 3, a light conversion element 4, and a collecting element 5.

Wherein the light source 2 is used for emitting excitation light. In the present embodiment, the light source 2 is preferably a solid-state light source. The light source 2 is a laser light source and/or an LED light source. The laser light source may be in the form of a single laser or in the form of a laser array. Similarly, the LED light source may be in the form of a single LED or an array of LEDs. The light source 2 may be other light sources, and is not limited herein.

The heat sink 1 is used to dissipate heat of the light source 2. Specifically, the light source 2 of the present embodiment preferably has a square structure, and includes a light emitting surface 21, two

side surfaces

22 and 23 adjacent to the light emitting surface 21, and a side surface 24 opposite to the light emitting surface 21. Wherein the area of the light emitting surface 21 is smaller than the areas of the

side surfaces

22 and 23. In the present embodiment, it is preferable that the side surface 23 is fixed to the heat dissipation member 1, so that a contact area of the light source 2 with the heat dissipation member 1 can be increased, thereby facilitating heat dissipation of the light source 2.

In the present embodiment, the heat sink 1 is preferably a heat conductive plate. Further, a heat-dissipating fin 12 may be further provided on one side of the heat-conducting plate 11. As shown in fig. 2. The heat generated from the light source 2 is transferred to the heat radiating fins 12 through the heat conductive plate 11, and the heat radiating fins 12 transfer the heat to the outside air. In addition, a heat pipe can be arranged on the heat dissipation toothed sheet 12, and part of heat is transferred to the outside through the heat pipe.

The light uniformizing element 3 is for uniformizing the excitation light emitted from the light source 2. In this embodiment, the light uniformizing element 3 may be a light uniformizing rod, a fly-eye lens or a fly-eye lens pair. The shape of the dodging rod can be a cone or a square, the outlet surface of the dodging rod can be set to be a specific shape, and each lens unit of the fly-eye lens can be a square or a circle.

The light after the dodging enters the light conversion element 4. Referring to fig. 3, the light conversion device 4 includes an incident region 41, a light emitting unit 44, a reflective region 45, a light emitting region 43, and a light recycling region 42.

The incident region 41, the light emitting unit 44, the reflective region 45, the light exiting region 43 and the light recycling region 42 enclose a space structure, and the reflective region 45 is disposed around the light emitting unit 44.

Wherein the incidence area 41 is used for incidence of the excitation light, i.e. for receiving the light after being homogenized by the light homogenizing element 3. The light emitting unit 44 is disposed inside the light conversion element 4, and receives incident excitation light to generate stimulated light. The reflection region 45 serves to reflect at least part of the received laser light to the light exit region 43 and to reflect excitation light, which is not absorbed by the light emitting unit 44, to the light emitting unit 44. The reflection region 45 is disposed between the incident region 41 and the light exit region 43, and is located on the side wall of the light conversion element 4. The reflective area 45 may be silver, alumina, or the like coated on the light conversion member 4.

The light emitting region 43 emits at least part of the received laser light. The light recycling region 42 is configured to reflect the excitation light and/or the stimulated light incident to the light recycling region, so that the stimulated light is reflected by the reflecting region and then emitted from the light emitting region, and the excitation light is converted by the light emitting unit to generate stimulated light and/or the stimulated light is emitted from the light emitting region, that is, the excitation light and/or the stimulated light incident to the light recycling region is reflected to recycle the excitation light and/or the stimulated light. Specifically, the light reflected by the light recovery area 42 includes the following three types:

the first method comprises the following steps: the received laser light is reflected. That is, the light receiving laser light converted by the light emitting unit 44 is not entirely emitted from the light emitting region 43, but is partially incident on the light collecting region 42. At this time, the portion of the light recovery region 42 to which light is incident is subjected to laser emission for recovery and reuse.

And the second method comprises the following steps: the excitation light is reflected. That is, the excitation light incident from the incident region 41 is not entirely converted into stimulated light by the light emitting unit 44, for example, a portion of the excitation light is transmitted between the light emitting unit 44 and the reflection region 45, and the portion of the excitation light is incident into the light recovery region 42, and the light recovery region 42 reflects the portion of the excitation light for recovery and reuse.

And the third is that: the excitation light and the stimulated light are reflected. This case is a combination of the first case and the second case described above, in which the excited light that is not emitted from the light exit region 43 and the excited light that is not converted by the light emitting unit 44 are incident on the light recovery region 42, and the light recovery region 42 reflects and recovers the excited light and the received laser light together.

The collecting element 5 is used for receiving the excited light emitted by the light conversion element 4. The collecting element 5 is preferably a collection lens group.

Therefore, the light source system of the embodiment of the present invention collects the incident excitation light and/or stimulated light by disposing the light recycling region 42, so that the incident excitation light and/or stimulated light can be reflected back to the inside of the light emitting unit 44 for reuse. Other elements are not required to be added, so that the volume of the product can be reduced, the cost is reduced, and meanwhile, the utilization rate of light is improved to realize high-brightness display.

In the present embodiment, a dichroic element 411 is provided on the incident area 41 for selectively transmitting the excitation light and reflecting the stimulated light. I.e. the dichroic element 411, acts as a filter. In this embodiment, the dichroic element 411 filters light from both color and angle.

First, the color filter dichroic element 411 is provided to allow only light of a specific color to pass therethrough, and to reflect light of other colors, for example, only blue light to pass therethrough, and light of other colors to reflect, whereby color selection of light emitted from the light source 2 can be performed.

Second, the angular filtering dichroic element 411 is configured to allow only certain angles of light to pass through, while reflecting other angles of light. This utilizes the characteristic that the angle of the light emitted from the light source 2 is different from the angle of the stimulated light formed after passing through the light emitting unit 44. For example, when the light source 2 is a laser light source, the angle of the emitted laser light may be approximately zero, and the received laser light formed after passing through the light emitting unit 44 is in a divergent state, and the angle is large. Therefore, the present embodiment provides an angle selective reflective layer on the dichroic element 411 for transmitting light with a small angle and reflecting light with a large angle, so that the excitation light emitted from the light source 2 is transmitted and the excited light converted by the light emitting unit 44 is reflected. The angle selective reflective layer may be a filter or a film filter. More specifically, when the angle selective reflective layer is a filter, the dichroic element 411 may be a film that transmits the excitation light and reflects the stimulated light, or a film that transmits the excitation light and reflects other light. Thus, the light emitted from the light source 2 may pass through the dichroic element 411, and the laser light reflected from the light recovery region 42 and passing through the light emitting unit 44 again may be further reflected by the dichroic element 411. Therefore, the loss of light can be reduced, and the utilization rate of light is ensured.

In the present embodiment, the light emitting unit 44 is any ceramic body that generates stimulated light when excited by excitation light. Preferably, the light emitting unit 44 is a pure-phase fluorescent ceramic or composite ceramic material, and is a solid element having a specific shape, such as a rectangular parallelepiped, a cube, a sphere, or the like. When the fluorescent ceramic is pure-phase fluorescent ceramic, the fluorescent ceramic can be various oxide ceramics, nitride ceramics or oxynitride ceramics, and a luminescent center is formed by doping a trace of activator elements such as lanthanide elements in the preparation process of the ceramic.

When the light-emitting unit 44 is a composite ceramic material, it has a transparent or translucent ceramic as a matrix, and light-emitting ceramic particles, such as phosphor particles, are distributed in the ceramic matrix. The transparent or translucent ceramic substrate may be a variety of oxide ceramics, such as alumina ceramics and Y₃Al₅O₁₂The ceramic may also be a nitride ceramic, such as an aluminum nitride ceramic, or an oxynitride ceramic.

In addition, the ceramic matrix may be a phase-pure fluorescent ceramic, i.e., the ceramic matrix itself has an activator and can emit excited light under irradiation of excitation light.

The phosphor of the light emitting unit 44 may be a mixture of green phosphor and red phosphor, or yellow phosphor, or a phosphor that is set in different regions, wherein different colors of phosphors are set in different regions.

In the present embodiment, the shape of the light conversion element 4 is preferably a rectangular parallelepiped or a cube, so that the plating of the incident region 41 and the like is simpler.

In this embodiment, the aspect ratio of the light exit region 43 matches the aspect ratio of the projection screen. More specifically, the aspect ratio of the light exit region 43 is preferably 4: 3 or 16: 9. therefore, the length and the width of the emitted laser light can be matched with the length and the width of the projection screen, and the light is better in uniformity and higher in light efficiency.

The light emitting area 43 is square, the light emitting area 43 and the light recycling area 42 are located on the same plane, and the light recycling area 42 is connected with the edge of the light emitting area 43.

In the present embodiment, the incident region 41 and the light exit region 43 may be located at arbitrary positions of the light conversion element 4. As shown in fig. 3, the light conversion member 4 is a cube of six faces, and the incident region 41 and the light exit region 43 are disposed on two opposite side faces of the light conversion member 4. The light recovery region 42 is located on the same side surface as the light exit region 43, the light exit region 43 is provided at the center of the side surface, and the light recovery region 42 is provided around the light exit region 43. The light emitting unit 44 is disposed inside the light conversion element 4. The reflection region 45 is preferably disposed between the light recovery region 42 and the light exit region 43, and is disposed around the light emitting unit 44.

In other embodiments, the incident region 41 and the light exit region 43 may also be disposed on two adjacent sides, as shown in fig. 4. Thereby, the number of times of reflection of light at the light emitting unit 44 can be increased, so that the emitted light is more uniform and the effective light is more, improving the brightness.

In other embodiments, the incident region 41 and the light exit region 43 may also be disposed on the same side. When the incident region 41 and the light exit region 43 are disposed on the same side, and there is an overlapping region, the overlapping region transmits visible light.

As described above, the light recovery region 42 and the light exit region 43 are disposed on the same plane. More specifically, the light recovery region 42 is a reflective layer provided at a position other than the light exit region 43 in the same plane, and the reflective layer is made of a material such as silver or alumina.

As mentioned above, the present invention recycles the non-emitted received laser light through the light recycling region 42 for recycling, so as to improve the light utilization rate, and thus improve the brightness of the light source system 10.

Referring to fig. 5, fig. 5 is a schematic structural diagram of another light conversion device according to an embodiment of the present invention. As shown in fig. 5, the light conversion element 50 of the present embodiment still includes an incident region 51, a light exit region 53, a light emitting unit 54, and a light recycling unit 52. The light conversion element 50 of the present embodiment is different from the light conversion element 4 described above in that: the light exit region 53 of the light conversion element 50 of the present embodiment is a spherical crown surface or a paraboloid, and the light recovery region 52 is provided at a position of the spherical crown surface or the paraboloid where the light exit region 53 is not provided. Since the light exit region 53 is disposed along the circumferential direction of the light exit region 53, the light reflected by the light recovery region 52 is concentrated toward the focal point of the spherical center or the paraboloid of the spherical crown surface, i.e., is concentrated and reflected back to the light emitting unit 54, and thus the reflection region 45 shown in fig. 3 and 4 can be omitted.

Further, the light conversion element 50 of the present embodiment further includes a light exit lens 56. Which is provided on one side of the light exit region 53 and condenses the light receiving laser light emitted from the light exit region 53. So that the relatively divergent received light emitted from the light-emitting region 53 forms the collected parallel light, thereby improving the utilization rate of the light.

Referring to fig. 6, fig. 6 is a schematic structural diagram of another light conversion device according to an embodiment of the present invention. As shown in fig. 6, the light conversion element 60 of the present embodiment still includes an incident region 61, a light exit region 63, a light emitting unit 64, a light recycling unit 62, and a reflection region 65. The light conversion element 60 of the present embodiment is different from the light conversion element 4 described above in that: the light exit region 63 and the light recovery region 62 of the light conversion element 60 of the present embodiment are provided on two different surfaces.

And the light recovery section 62 is a spherical crown or paraboloid. The incident region 61, the light emitting unit 64, the light exiting region 63, and the reflection region 65 are located at the center of the spherical crown surface or the focal point of the paraboloid.

The light-transmitting region 66 is disposed on the light-recovering region 62, the light-transmitting region 66 is disposed at the center of the spherical crown surface or the paraboloid, and the light-recovering region 62 is disposed at the position of the spherical crown surface or the paraboloid where the light-transmitting region 66 is not disposed. The light-transmissive region 66 may be a through hole or made of a light-transmissive material.

The light exit region 63 is located on the side of the concave surface of the spherical crown surface or the paraboloid, light of a large angle in the light exit region 63 is reflected by the light return region 62, and light of a small angle is emitted from the light transmission region 66. The specific optical path diagram is shown in fig. 7.

The embodiment of the invention also provides a display device which comprises the light source system. The display device is a micro-projection device, a laser television, an educational machine and the like.

In summary, the present invention can achieve high brightness display with low cost.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A light conversion element, comprising an incident region, a light emitting unit, a reflective region, a light emitting region and a light recycling region, wherein the incident region, the light emitting unit, the reflective region and the light emitting region enclose a space structure, the incident region and the light emitting region are disposed on two opposite sides of the light conversion element, the light emitting unit is disposed inside the light conversion element, and the reflective region is disposed around the light emitting unit; wherein:

the incidence area is used for incidence of exciting light;

the reflection region is used for reflecting at least part of the stimulated light to the light-emitting region and reflecting the exciting light which is not absorbed by the light-emitting unit to the light-emitting unit;

the light emergent area is used for emitting at least part of the received laser light;

the light emitting area and the light recycling area are located on the same plane, the light recycling area is connected with the edge of the light emitting area, and the light recycling area is used for reflecting the excitation light and/or the received laser light which enters the light recycling area to the light emitting unit.

2. The light conversion element according to claim 1, wherein a dichroic element is provided on the incident region to selectively transmit the excitation light and reflect the excited light.

3. The light conversion element according to claim 1, wherein an aspect ratio of the light exit region matches an aspect ratio of a projection screen.

4. The light conversion element according to claim 3, wherein an aspect ratio of the light exit region is 4: 3 or 16: 9.

5. the light conversion element according to claim 3, wherein the light exit region has a square shape.

6. The light conversion element according to claim 1, wherein the light emitting unit uses a phase-pure fluorescent ceramic or a composite ceramic material.

7. A light source system, comprising:

a light source for emitting excitation light;

the dodging element is used for dodging the exciting light;

a light conversion element for receiving the excitation light after dodging and generating stimulated light, wherein the light conversion element is the light conversion element in any one of claims 1-6;

8. The light source system of claim 7, further comprising:

the heat dissipation piece is used for dissipating heat of the light source.

9. A display device characterized in that the display device comprises a light source system according to any one of claims 7-8.