A light source system and a projection device

Abstract

The application protects a light source system, comprising: a first light module, the first light module comprising a first light source and a second light source, the first light source being used for emitting first light, and the second light source being used for emitting second light; a second light module, the second light module comprising a third light source, the third light source being used for emitting third light; and a light combining module, the light combining module being used for combining the first light, the second light and the third light; wherein the optical etendue of the first light and the optical etendue of the second light are respectively less than the optical etendue of the third light, the first light is blue laser, and the second light is red laser. Since the first light module and the second light module with different optical etendues are used, the first light is blue laser, and the second light is red laser, the light source system can emit higher brightness in a very small volume, and the design difficulty and manufacturing difficulty of optical elements in the light combining module are reduced.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a light source system and a projection device. Background Technology

[0002] With the advancement of information technology, people have increasingly higher demands for convenient interactive displays. For example, they need to create an interactive space, providing a surface for virtual activities such as games, art, and puzzles, giving people a sense of immersive experience. While mobile phones and smart tablets can achieve convenient displays, their display methods limit their ability to achieve truly interactive displays. Therefore, to achieve flexible interactive displays, projection technology is currently the only viable option.

[0003] In existing interactive projection technologies, since the brightness requirements of the usage scenarios are not high, most of them use LED combination light sources to achieve white light emission. However, due to the insufficient brightness of the LED light source itself, the high design difficulty of related optical components, and the difficulty in miniaturizing the size of the light source, the key optical components in the light source cannot be mass-produced. At the same time, due to the low light combining efficiency and short lifespan of LED light sources, the light source devices need to be replaced frequently. In addition, the color gamut of LED combination light sources is limited and cannot meet the user's requirements for high-quality interactive projection spaces. Therefore, how to provide a light source system that is low in cost, small in size, high in brightness, and has a good color gamut is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this application provides a low-cost, small-sized, high-brightness, and wide-color-gamut light source system to better suit projection systems. The system includes: a first light module comprising a first light source and a second light source, the first light source emitting a first light and the second light source emitting a second light; a second light module comprising a third light source emitting a third light; and a light combining module for combining the first light, the second light, and the third light; wherein the optical expansion of the first light and the second light is less than the optical expansion of the third light, the first light is a blue laser, and the second light is a red laser.

[0005] In some embodiments, the first optical module further includes a speckle reduction component, which is used to reduce speckle on the first light and the second light.

[0006] In some embodiments, the second optical module further includes: a collecting element for collecting the third light; a polarizing element disposed after the collecting element for polarizing the third light; and a recovering element disposed after the polarizing element for recovering the third light so that the third light is recovered onto the third light source.

[0007] In some embodiments, the second optical module further includes a collimating lens disposed in the outgoing light path of the collecting element to collimate the light rays.

[0008] In some embodiments, the second optical module further includes a supplementary light source for emitting excitation light, which illuminates the third light source. A third phosphor is disposed on the surface of the third light source, and the excitation light illuminates the third phosphor to generate supplementary light. The light combining module is used to combine the first light, the second light, the third light, and the supplementary light.

[0009] In some embodiments, the second optical module further includes a light combining element, which is used to reflect the third light, reflect the supplementary light, and transmit the excitation light.

[0010] In some embodiments, the light combining element includes a central aperture portion and a peripheral reflective portion, wherein the peripheral reflective portion is used to reflect the third light and the supplementary light, and the central aperture portion is used to transmit the excitation light.

[0011] In some embodiments, the light combining module includes a first light combining component and a second light combining component; the first light combining component is used to transmit the third light and reflect the first light; the second light combining component is disposed in the outgoing light path of the first light combining component, and the second light combining component is used to transmit the third light, transmit the first light, and reflect the second light.

[0012] In some embodiments, the first light combining component includes a first central portion and a first peripheral portion, the first peripheral portion being used to transmit the third light and the first central portion being used to reflect the first light; the second light combining component includes a second central portion and a second peripheral portion, the second peripheral portion being used to transmit the third light and the second central portion being used to transmit the first light and reflect the second light.

[0013] On the other hand, this application also provides a projection device, comprising: a light source system, wherein the light source system is the light source system described above; a light modulation system, wherein the light modulation system includes a light modulator, wherein the light modulator is an LCOS; and a lens system, wherein the lens system is a direct projection lens or an ultra-short throw lens.

[0014] Compared to existing technologies, this application utilizes a first optical module and a second optical module with different optical extensions. The first light is a blue laser, and the second light is a red laser. This enables the light source system to emit higher brightness in a very small volume. Compared to wavelength combining schemes, it reduces the design and manufacturing difficulty of optical components in the combining module. Compared to existing technologies that use multiple LEDs for projection, it improves the luminous efficiency of the light source system, expands the color gamut of the projected image, reduces the design difficulty of key optical components, avoids the need for frequent replacement of light source devices, and makes it possible for larger-scale mass production of projection products. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the basic optical architecture of the light source system;

[0016] Figure 2 This is a schematic diagram of one type of light source system in this application;

[0017] Figure 3 This is a schematic diagram of another light source system in this application;

[0018] Figure 4 This is a schematic diagram of the light-combining element in this application;

[0019] Figure 5 This is a schematic diagram of the light combining module in this application;

[0020] Figure 6 This is a schematic diagram of a projection device in this application;

[0021] Figure 7 This is another schematic diagram of the projection device in this application.

[0022] In the diagram: 100, Light source system; 110, First optical module; 111, First light source; 112, Second light source; 113, Speckle eliminator assembly; 114, Lens assembly; 120, Second optical module; 121, Third light source; 122, Collecting element; 123, Collimating lens; 124, Polarizing element; 125, Recovering element; 126, Supplementary light source; 127, Light combining element; 1271, Central aperture portion; 1272, Peripheral reflection portion; 130, Light combining module; 131, First light combining assembly; 1311, First central portion; 1312, First peripheral portion; 132, Second light combining assembly; 1321, Second central portion; 1322, Second peripheral portion; 200, Optical modulation system; 210, Reflector; 220, Polarizing beam splitter prism; 230, Optical modulator; 300, Lens system. Detailed Implementation

[0023] In related technologies, most light sources use a combination of red, blue, and green LEDs to achieve white light emission. However, due to the insufficient brightness of the LED light source itself, in environments with slightly higher brightness requirements, the only way to achieve higher brightness is to increase the number of LEDs. Since the brightness requirement for red LEDs is the highest, a combination of first red LED, second red LED, green LED, and blue LED is generally used to create the light source. However, because the spread of the emitted light from LEDs is relatively large, the design difficulty and light combining efficiency of the light combining element are high when combining light, especially when red LEDs and green LEDs are combined. Furthermore, the use of multiple LEDs results in a larger overall size of the light source for the same brightness requirement. Therefore, there is an urgent need for a light source system that is small in size, high in brightness, and has high light combining efficiency.

[0024] Therefore, this application proposes a novel light source system that fully utilizes the difference in optical extension between LED and laser light sources and redesigns the layout of optical components, effectively reducing costs, decreasing size, increasing brightness, and expanding color gamut. Understandably, the projection device of this application, in addition to being used in traditional projectors such as business and educational projectors, is also better suited for interactive projection scenarios such as desktop projection, miniature projectors, and mobile phone integrated projection due to its simple architecture and powerful functionality, possessing a very broad application prospect.

[0025] Please see Figure 1This is a schematic diagram of the basic optical architecture of the light source system 100 of this application. The light source system 100 includes a first optical module 110, a second optical module 120, a light combining module 130, and a light homogenizing module. The first optical module 110 includes a first light source 111 and a second light source 112. The first light source 111 is used to emit a first light, and the second light source 112 is used to emit a second light. The first light is a blue laser, and the second light is a red laser. The second optical module 120 includes a third light source 121, which is used to emit a third light. In this embodiment, the third light is green light. The light combining module 130 is used to combine the first light, the second light, and the third light. The methods that can be used include wavelength combining or expansion combining. The detailed structure will be described later and will not be elaborated here. The optical expansion of the first light and the optical expansion of the second light are respectively smaller than the optical expansion of the third light. For example, the third light can be broadband light emitted by an LED or fluorescence. Fluorescence can be generated in the form of a fixed phosphor sheet, a color wheel, etc., which is not limited here. The third beam can be a laser, preferably a linearly polarized laser. The optical expansion of the first and second beams is smaller than that of the third beam. Therefore, when combining the first, second, and third beams, the differences in their spectral density and optical expansion can be fully utilized, resulting in a further increase in brightness while reducing the overall size of the light source. Simultaneously, because the third beam in the third beam module has a large optical expansion, non-imaging optics principles can be fully utilized to recover and reuse the light emitted from the third beam module, significantly improving the light extraction efficiency of the light source.

[0026] The embodiments of this application will now be described in detail with reference to the accompanying drawings and implementation details.

[0027] Please see Figure 2 This is a schematic diagram of the structure of a first embodiment of the light source system 100 of this application. The first optical module 110 of the light source system 100 includes a first light source 111, a second light source 112, a speckle reduction component 113, and a lens assembly 114. The speckle reduction component 113 is used to reduce speckle on the first light and the second light. Specifically, the first light source 111 is a blue laser and the second light source 112 is a red laser; the speckle reduction component 113 includes a first scattering plate and a second scattering plate. The first scattering plate is used to reduce speckle on the first light emitted by the first light source 111, and the second scattering plate is used to reduce speckle on the second light emitted by the second light source 112; the lens assembly 114 includes a first lens and a second lens. When the speckle of the first light and the second light is large, or when the first light source 111 and the second light source 112 use an array laser, the first lens and the second lens can collect the first light and the second light respectively, ensuring that the optical expansion of the first light and the optical expansion of the second light are respectively less than the optical expansion of the third light.

[0028] The second optical module 120 of the light source system 100 includes a third light source 121, a collecting element 122, a polarizing element 124, and a recovering element 125. The third light source 121 emits a third light; in this embodiment, the third light source 121 is a green LED light source, and the third light is green. The collecting element 122 is disposed in the output light path of the third light source 121 to collect the light emitted from the third light source 121 and illuminate the polarizing element 124. The polarizing element 124 is disposed in the output light path of the collecting element 122 to polarize the third light emitted from the collecting element 122, thereby matching the subsequent optomechanical system (detailed later, not repeated here). The polarizing element 124 can be a linear polarizer. A recovering element 125 is also disposed in the output light path of the polarizing element 124. The recovering element 125 allows the polarized light of the first polarization state to pass through and reflects the light of the second polarization state, which is perpendicular to the first polarization state, back to the third light source 121 for reuse. In some embodiments, the recovery element 125 is a reflective polarizing brightness enhancement film (DBEF). In some embodiments, the polarizing element 124 and the recovery element 125 are designed as an integral part, which can effectively reduce the size of the second optical module 120.

[0029] In some embodiments, the second optical module 120 further includes a collimating lens 123. The collecting element 122 can be a conical reflector or a collecting lens, and the collimating lens 123 is disposed in the outgoing light path of the collecting element 122. The smaller end of the conical reflector is the incident surface, and the larger end is the exit surface. This allows the third light emitted by the third light source 121 to enter the conical reflector through the incident surface, and then be reflected by the sidewall of the conical reflector before exiting through the exit surface or directly. This results in the area of ​​the exit light spot being larger than the area of ​​the incident light spot, thereby reducing the divergence angle of the beam and allowing the third light to be emitted in a non-imaging manner to match the subsequent modulation optical module. In this embodiment, the conical reflector is a solid conical light guide rod, and the beam is reflected on the side of the conical reflector by total internal reflection. In other embodiments of this application, the conical reflector can also be a hollow conical reflector composed of a reflective plate / reflective surface, which will not be described further here. The collimating lens 123 can be a Fresnel lens, a freeform lens, or the like, which can collimate the light spot to match the illumination part required by the subsequent modulation panel.

[0030] In some embodiments, see Figure 3The second optical module 120 also includes a supplementary light source 126, which emits excitation light. The excitation light illuminates the third light source 121, whose surface is coated with a third phosphor. The excitation light illuminates the third phosphor to generate supplementary light, which is then reflected by the third light source 121 and enters the light combining module 130. In this embodiment, the supplementary light source 126 is a blue laser, and the third light source 121 is a green LED. The surface of the third light source 121 is coated with green phosphor. After the blue laser illuminates the green phosphor on the surface of the third light source 121, it remotely excites and generates green fluorescence. The green fluorescence is reflected by the green LED and then illuminates the light combining module 130. This configuration further increases the efficiency of the light source system 100 in generating green light. Since green light contributes more to the brightness of white light, this configuration helps to significantly improve the brightness of the light source.

[0031] In some embodiments, see Figure 3 and Figure 4 The second optical module 120 also includes a light combining element 127, which is used to reflect the third light, reflect the supplementary light, and transmit the excitation light. By utilizing the reflection and transmission characteristics of the light combining element 127, the arrangement direction of the second optical module 120 can be made perpendicular to the arrangement direction of the light combining module 130, thereby freeing up space for the supplementary light source 126 to remotely excite and generate green fluorescence.

[0032] In some embodiments, see Figure 4 The light combining element 127 includes a central aperture portion 1271 and a peripheral reflective portion 1272. The peripheral reflective portion 1272 is used to reflect the third light and the supplementary light, while the central aperture portion 1271 is used to transmit the excitation light. Since the optical expansion of the excitation light (blue laser) emitted by the supplementary light source 126 is small, while the optical expansion of the third light (green LED light) emitted by the third light source 121 and the supplementary light (green fluorescence) generated by the excitation is large, the excitation light can be incident according to the difference in optical expansion, and the third light and the supplementary light are combined and then emitted to the light combining module 130.

[0033] In some embodiments, see Figure 2 and Figure 5 The light combining module 13030 may include a first light combining component 131 and a second light combining component 132. The first light combining component 131 is used to transmit a third light (including supplementary light) and reflect a first light. The second light combining component 132 is disposed on the outgoing light path of the first light combining component 131 and is used to transmit the third light (including supplementary light), transmit the first light, and reflect a second light. By achieving light combining through such a configuration, the optical path volume can be further reduced.

[0034] In some embodiments, see Figure 2 and Figure 5The light combining module 130 can also achieve light combining through an expansion-based light combining method. Specifically, the first light combining component 131 includes a first central portion 1311 and a first peripheral portion 1312. The first peripheral portion 1312 is used to transmit the third light (including supplementary light), and the first central portion 1311 can be a reflective film used to reflect the first light. The second light combining component 132 includes a second central portion 1321 and a second peripheral portion 1322. The second peripheral portion 1322 is used to transmit the third light (including supplementary light), and the second central portion 1321 can be a dichroic film that transmits blue and reflects red, used to transmit the first light and reflect the second light. With this configuration, the difference between the expansion amount of the third light and the expansion amount of the first and second light can be fully utilized, thereby achieving light combining through an expansion-based light combining method. This scheme, which involves combining light based on wavelength, can maximize the input of red and blue lasers into the subsequent optical system. Since red light itself is not very efficient, this design can maximize the utilization of red laser light.

[0035] In some embodiments, see Figure 2 The light source system 100 also includes a light homogenizing module, which is disposed in the light path emitted from the light combining module 130 and is used to homogenize the light after it is combined by the light combining module 130. Preferably, the light homogenizing module includes a light homogenizing element (not shown in the figure), which can be a compound eye lens or a square rod. The compound eye lens is particularly suitable for embodiments that combine the light with the expansion amount of the light combining module 130.

[0036] Please see Figure 6 This application provides a projection device that includes the aforementioned light source system 100, and the projection device further includes a light modulation attraction and lens system 300.

[0037] In some embodiments, the optical modulation system 200 includes a reflector 210, a polarizing beam splitter 220, and an optical modulator 230, wherein the tilt direction of the reflector 210 is parallel to the tilt direction of the first beam combining component 131 and the second beam combining component 132 in the beam combining module 130, and the tilt angle of the first beam combining component 131 and the second beam combining component 132 is 135 degrees with the horizontal direction. A polarizing beam splitter 220 is disposed in the outgoing light path of the reflector 210 to direct the light reflected by the reflector 210 into the light modulator 230. The light modulator 230 modulates the incident light. A beam-splitting film is disposed in the middle of the polarizing beam splitter 220, with its tilt direction parallel to that of the reflector 210. This film reflects light of the first polarization state and transmits light of the second polarization state. The light modulator 230 is a liquid crystal on silicon (LCOS) capable of modulating the light of the first polarization state. In this embodiment, the first polarization state is S-polarized light, and the second polarization state is P-polarized light. A direct-projection lens is also disposed in the gap between the right side of the light modulation system 200 and the upper side of the light source system 100. This fully utilizes both vertical and horizontal space, resulting in a compact optical path layout and small size. Furthermore, by employing LCOS for modulation, the principle of reflective modulation is fully utilized, further reducing the optical path volume.

[0038] In some embodiments, see Figure 7 In another embodiment of the projection device shown, the light modulation module includes a reflector 210, a polarizing beam splitter 220, and a light modulator 230. The tilt direction of the reflector 210 is perpendicular to the tilt directions of the first beam combining component 131 and the second beam combining component 132 in the beam combining module 130. The tilt angle between the first beam combining component 131 and the second beam combining component 132 and the horizontal direction is 135 degrees. The polarizing beam splitter 220 is disposed in the outgoing light path of the reflector 210 and is provided with a beam splitting film. The tilt direction of the beam splitting film is parallel to the tilt direction of the reflector 210. It is used to direct the light reflected by the reflector 210 onto the light modulator 230. The light modulator 230 modulates the incident light. Specifically, the polarizing beam splitter 220 reflects light of the first polarization state and transmits light of the second polarization state. The light modulator 230 is the same as in the previous embodiment and will not be described again here. An ultra-short focal length lens is also provided in the gap between the right side of the light modulation module and the left side of the light source system 100. This makes full use of the vertical and horizontal space, making the layout of the entire optical path in the horizontal space more compact and smaller in size.

[0039] The light source system 100 and projection system provided in this embodiment, by using a first optical module 110 and a second optical module 120 with different optical extensions, where the first light is a blue laser and the second light is a red laser, enable the light source system 100 to emit higher brightness in a very small volume. Compared with wavelength combining schemes, it reduces the design and manufacturing difficulty of optical components in the combining module 130. Compared with the existing technology of using multiple LEDs to achieve projection, it can improve the luminous efficiency of the light source system 100, increase the color gamut of the image emitted by the projection device, reduce the design difficulty of key optical components, avoid the need for frequent replacement of light source devices, and provide the possibility for larger-scale mass production of projection products.

[0040] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0041] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A light source system, characterized in that, include: A first optical module, comprising a first light source and a second light source, wherein the first light source is used to emit a first light and the second light source is used to emit a second light; The second optical module includes a third light source, a collecting element, a polarizing element, a recovering element, a supplementary light source, and a combining element. The third light source is used to emit third light; the collecting element is used to collect the third light. The polarizing element is disposed after the collecting element, and the polarizing element is used to polarize the third light; The recovery element is disposed after the polarizing element, and the recovery element is used to recover the third light so that the third light is recovered onto the third light source; the supplementary light source is used to emit excitation light, and the excitation light irradiates the third light source. The surface of the third light source is provided with third light phosphor, and the excitation light irradiates the third light phosphor to generate supplementary light; the light combining element is used to reflect the third light, reflect the supplementary light, and transmit the excitation light. as well as A light combining module, which is used to combine the first light, the second light, the third light and the supplementary light; Wherein, the optical expansion of the first light and the optical expansion of the second light are respectively less than the optical expansion of the third light, the first light is a blue laser, and the second light is a red laser.

2. A light source system as described in claim 1, characterized in that, The first optical module also includes: A speckle-reducing component, the speckle-reducing component being used to reduce speckle on the first light and the second light.

3. A light source system as described in claim 1, characterized in that, The second optical module further includes a collimating lens, which is disposed in the outgoing light path of the collecting element to collimate the third light.

4. A light source system as described in claim 1, characterized in that, The light combining element includes a central aperture portion and a peripheral reflective portion. The peripheral reflective portion is used to reflect the third light and the supplementary light, while the central aperture portion is used to transmit the excitation light.

5. A light source system as described in claim 1, characterized in that, The light combining module includes a first light combining component and a second light combining component; The first light combining component is used to transmit the third light and reflect the first light; The second light combining component is disposed in the output light path of the first light combining component, and the second light combining component is used to transmit the third light, transmit the first light, and reflect the second light.

6. A light source system as described in claim 5, characterized in that, The first light combining component includes a first central portion and a first peripheral portion, wherein the first peripheral portion is used to transmit the third light and the first central portion is used to reflect the first light; The second light combining component includes a second central portion and a second peripheral portion. The second peripheral portion is used to transmit the third light, and the second central portion is used to transmit the first light and reflect the second light.

7. A projection device, characterized in that, include: A light source system, wherein the light source system is the light source system according to any one of claims 1-6; An optical modulation system, the optical modulation system including an optical modulator, the optical modulator being an LCOS; as well as The lens system is either a direct-projection lens or an ultra-short-throw lens.

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