LCOS projection device

Abstract

The utility model relates to an LCOS (Liquid Crystal On Silicon) projection device, which comprises a light source module capable of emitting red, green and blue light beams, a polarization filter and an imaging lens which are sequentially arranged along a projection light path, an LCOS chip capable of modulating the polarization state of incident light is arranged on a projection light path between the polarization filter and the imaging lens, and an imaging lens group capable of imaging the incident light onto the LCOS chip is arranged on a projection light path between the light source module and the polarization filter. And a polarization layer capable of transmitting P polarized light and reflecting S polarized light is arranged on the polarization filter. Compared with a polarizing prism applied to a traditional LCOS projection light path, the LCOS projection light path has the advantages that through the arrangement of the polarizing filter and the polarizing layer which is arranged on the polarizing filter and can transmit P polarized light and reflect S polarized light, the LCOS projection light path has higher polarization efficiency, stray light is reduced, and optical efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of projection equipment, in particular to an LCOS projection device. Background Art

[0002] LCOS displays, a new type of reflective projection display, project color images by using semiconductor silicon technology to control liquid crystals. Compared to common display technologies such as transmissive LCDs and DLP displays, LCOS displays more easily achieve high resolution and rich color rendering while also offering advantages such as high light efficiency, compact size, and a high aperture ratio.

[0003] Existing LCOS projection devices typically use a polarizing prism to convert unpolarized light into polarized light. Chinese patent publication number CN105929625B discloses an LCOS projector that uses a polarizing prism to separate S-polarized light from P-polarized light. The LCOS chip then emits modulated polarized light to an imaging lens for imaging. However, polarizing prisms are expensive to manufacture, and light often scatters or absorbs during transmission through the prism, resulting in poor contrast. Furthermore, ineffectively modulated polarized light may enter the final projection path through the scattering of the polarizing prism, causing increased background brightness in dark images and reduced contrast in dark details. Utility Model Content

[0004] The purpose of the present invention is to provide an LCOS projection device that can be used for head-up display, thereby solving the above-mentioned problems.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an LCOS projection device, comprising a light source module capable of emitting red, green and blue light beams, a polarizing filter, and an imaging lens, wherein the light source module, polarizing filter and imaging lens are arranged in sequence along the projection light path, an LCOS chip capable of modulating the polarization state of the incident light is provided on the projection light path between the polarizing filter and the imaging lens, an imaging lens group capable of imaging the incident light onto the LCOS chip is provided on the projection light path between the light source module and the polarizing filter, and a polarizing layer capable of transmitting P-polarized light and reflecting S-polarized light is provided on the polarizing filter.

[0006] As a further optimization solution of the present invention, the material of the polarizing filter includes glass, and the polarizing layer is coated on the surface of the polarizing filter at a high temperature.

[0007] As a further optimization solution of the present invention, the material of the polarizing layer includes plastic, and the surface of the polarizing layer has a polarizing structure formed by coating or rolling.

[0008] As a further optimization scheme of the present invention, the LCOS chip is arranged on the transmission light path of the polarizing filter, and the LCOS chip can modulate the incident light into S-polarized light. The polarizing filter can reflect the S-polarized light modulated by the LCOS chip to the imaging lens. A first polarizer capable of filtering P-polarized light is provided on the projection light path between the light-emitting side of the polarizing filter that reflects the S-polarized light modulated by the LCOS chip and the imaging lens.

[0009] As a further optimization scheme of the present invention, the LCOS chip is arranged on the reflection light path of the polarizing filter, and the LCOS chip can modulate the incident light into P-polarized light. The polarizing filter can transmit the P-polarized light modulated by the LCOS chip to the imaging lens, and a second polarizer capable of filtering P-polarized light is provided on the projection light path between the imaging lens group and the polarizing filter.

[0010] As a further optimization solution of the present invention, a compensation plate for compensating for the phase difference of LCOS polarization conversion is provided between the polarization filter and the LCOS chip.

[0011] As a further optimization solution of the present invention, a compound eye is provided on the projection light path between the light source module and the imaging lens group.

[0012] As a further optimization scheme of the present invention, the light source module includes a blue light LED element, a red light LED element, and a green light LED element arranged in parallel in sequence. The light-emitting side of the blue light LED element is provided with a reflector for reflecting blue light, the light-emitting side of the red light LED element is provided with a first dichroic plate that reflects red light and transmits blue light, and the light-emitting side of the green light LED element is provided with a second dichroic plate that reflects green light and transmits red and blue light.

[0013] As a further optimization solution of the present invention, a first relay lens capable of enhancing the collimation of blue light is provided on the projection light path between the reflector and the first dichroic plate, and a second relay lens capable of enhancing the collimation of blue light and red light is provided on the projection light path between the first dichroic plate and the second dichroic plate.

[0014] As a further optimization solution of the present invention, a collimating lens group is provided on the light-emitting side of the blue light LED component, the red light LED component, and the green light LED component.

[0015] Compared with the prior art, the utility model has the following advantages:

[0016] 1. The polarizing filter and the polarizing layer on the polarizing filter that transmits P-polarized light and reflects S-polarized light have higher polarization efficiency than the polarizing prism used in the traditional LCOS projection optical path, thereby reducing the generation of stray light and improving optical efficiency.

[0017] 2. Compared with polarizing prisms, polarizing filters with polarizing layers can be used in conjunction with LCOS chips to reduce the chance of unmodulated polarized light directly entering the subsequent system due to scattering, thereby improving background brightness in dark images and enhancing the overall contrast of the image.

[0018] 3. Reduce the cost of the entire system by using a polarizing filter with a polarizing layer to replace the polarizing prism in the traditional LCOS projection light path;

[0019] 4. By setting a polarizing filter with a polarizing layer, the structure of the optical system can be simplified, making the structure of the entire device more compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model;

[0021] Figure 2 A schematic diagram of the structure of Example 2 of the utility model. DETAILED DESCRIPTION

[0022] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings.

[0023] like Figure 1 、 Figure 2 As shown, the utility model discloses an LCOS projection device, including a light source module 1 capable of emitting red, green and blue light beams, a polarizing filter 2, and an imaging lens 3. The light source module 1, the polarizing filter 2, and the imaging lens 3 are arranged in sequence along the projection light path. An LCOS chip 4 capable of modulating the polarization state of incident light is provided on the projection light path between the polarizing filter 2 and the imaging lens 3. An imaging lens group 5 capable of imaging the incident light onto the LCOS chip 4 is provided on the projection light path between the light source module 1 and the polarizing filter 2. The polarizing filter 2 is provided with a polarizing layer 21 capable of transmitting P-polarized light and reflecting S-polarized light.

[0024] The light source module 1 can provide red, green, and blue light sources, providing a color foundation for the projection system. The polarizing filter 2 is provided with a polarizing layer 21 that can transmit P-polarized light and reflect S-polarized light, allowing the polarizing filter 2 to separate and reassemble polarized light. The imaging lens 3 can focus the light modulated by the LCOS chip 4 onto the screen to form a clear image. The imaging lens group 5 can image the incident light onto the LCOS chip 4 to achieve focusing of the light. The LCOS chip 4 can modulate the polarization state of the incident light and cooperate with the polarizing filter 2 to achieve high-contrast image display.

[0025] like Figure 1 、 Figure 2As shown, after the light beam is emitted by the light source module 1, it is imaged onto the Lcos chip 4 through the imaging lens group 5, where the light beam is separated by the polarizing filter 2 to realize polarized light separation, and the separated polarized light is modulated by the Lcos chip 4, and the modulated polarized light then passes through the polarizing filter 2 to enter the imaging lens 3.

[0026] By setting up a polarizing filter 2 and a polarizing layer 21 on the polarizing filter 2 that can transmit P-polarized light and reflect S-polarized light, the polarization efficiency is higher than that of a polarizing prism used in a traditional LCOS projection optical path, thereby reducing the generation of stray light and improving optical efficiency; compared with a polarizing prism, the polarizing filter 2 with the polarizing layer 21 cooperates with the LCOS chip 4 to reduce the chance of unmodulated polarized light caused by scattering directly entering the subsequent system, improves the background brightness in dark images, and improves the overall contrast of the image; by using the polarizing filter 2 with the polarizing layer 21 to replace the polarizing prism in the traditional LCOS projection optical path, the cost of the entire system is reduced; by setting up the polarizing filter 2 with the polarizing layer 21, the structure of the optical system can be simplified, making the structure of the entire device more compact.

[0027] The polarizing filter 2 is made of glass, and the polarizing layer 21 is formed by high-temperature coating on the surface of the polarizing filter 2 .

[0028] In one embodiment, a high-temperature coating is directly applied to a glass substrate via an inorganic process, enabling the polarizing layer 21 to maintain stable optical properties over a wide temperature range. Furthermore, the polarizing layer 21 formed by the coating exhibits high transmittance, reducing light scattering and loss, and improving image clarity.

[0029] The polarizing layer 21 is made of plastic, and a surface of the polarizing layer 21 has a polarizing structure formed by coating or rolling.

[0030] In one embodiment, a microstructure is formed on the surface of a plastic film through an organic process, such as coating or rolling. The polarizing layer 21 is made of plastic, making it lightweight and cost-effective. The polarizing structure formed on the surface of the polarizing layer 21 by coating or rolling is easy to process and form, and the polarizing structure formed by coating or rolling can achieve efficient polarized light separation.

[0031] The LCOS chip 4 is arranged on the transmission light path of the polarizing filter 2, and the LCOS chip 4 can modulate the incident light into S-polarized light. The polarizing filter 2 can reflect the S-polarized light modulated by the LCOS chip 4 to the imaging lens 3. A first polarizer 61 capable of filtering P-polarized light is provided on the projection light path between the light-emitting side of the polarizing filter 2 that reflects the S-polarized light modulated by the LCOS chip 4 and the imaging lens 3.

[0032] When P polarized light is incident, most of the P polarized light is transmitted and recorded as Tp, and a small part is reflected and recorded as Rp; when S polarized light is incident, most of the S polarized light is reflected and recorded as Rs, and a small part of the S polarized light is transmitted and recorded as Ts. Figure 1 As shown, in one embodiment, a mixed beam of S-polarized and P-polarized light passes through the polarizing filter 2, with the P-polarized light penetrating the polarizing layer 21 and reaching the LCOS chip 4. When the image is white, the LCOS chip 4 converts the P-polarized light into S-polarized light, which then reflects off the polarizing filter 2 through the polarizing layer 21. At this point, the illumination of the white image is Tp*Rs+Ts*Rs. When the image is dark, the LCOS chip 4 does not convert the P-polarized light, and the P-polarized light returns along the original path. At this point, the brightness of the dark image is Tp*Rp+Ts*Rs. The contrast ratio is calculated as (Tp*Rs+Ts*Rs) / (Tp*Rp+Ts*Rs), with Rp typically being much larger than Rs. A first polarizer 61, capable of filtering P-polarized light, is provided in the projection optical path between the light-exiting side of the polarizing filter 2 that reflects the S-polarized light modulated by the LCOS chip 4 and the imaging lens 3. This first polarizer absorbs the P-polarized light, thereby reducing the Rp value and increasing the contrast ratio. The projection effect is achieved by using an LCOS chip 4, located in the transmission light path of the polarizing filter 2 and capable of modulating incident light into S-polarized light, and a first polarizer 61, located in the projection light path between the light-exit side of the polarizing filter 2 that reflects the S-polarized light modulated by the LCOS chip 4 and the imaging lens 3, capable of filtering P-polarized light. By selecting a suitable transmission structure, light first passes through the polarizing filter 2 to the LCOS chip 4 and then returns. This significantly increases contrast based on optical path design principles, material manufacturing processes, and properties. Furthermore, in this embodiment, it can be seen that achieving sufficiently high contrast requires improving Ts; lower Ts results in higher contrast. Compared to conventional polarizing prisms in the projection light path, the polarizing filter 2 with a polarizing layer 21 can more effectively reduce Ts, thereby achieving superior contrast.

[0033] The LCOS chip 4 is arranged on the reflected light path of the polarizing filter 2, and the LCOS chip 4 can modulate the incident light into P-polarized light. The polarizing filter 2 can transmit the P-polarized light modulated by the LCOS chip 4 to the imaging lens 3. A second polarizer 62 capable of filtering P-polarized light is provided on the projection light path between the imaging lens group 5 and the polarizing filter 2.

[0034] like Figure 2As shown, in one embodiment, a second polarizer 62 capable of filtering P-polarized light is provided in the projection light path between the imaging lens assembly 5 and the polarizing filter 2, thereby filtering out the P-polarized light in the mixed beam of S-polarized and P-polarized light. The S-polarized light passes through the polarizing filter 2, where it is reflected by the polarizing layer 21 and reaches the LCOS chip 4. The LCOS chip 4 modulates the incident light into P-polarized light, which is then emitted through the polarizing filter 2 to the imaging lens 3. The projection effect is achieved by the LCOS chip 4, which is located in the reflected light path of the polarizing filter 2 and capable of modulating the incident light into P-polarized light, and the second polarizer 62, which is located in the projection light path between the imaging lens assembly 5 and the polarizing filter 2 and capable of filtering P-polarized light. In this embodiment, the polarization transmittance of the second polarizer 62 is 0.01%. At this time, the brightness of the white screen is equivalent to Rs*Tp+Rp*0.01%. When the screen is dark, Lcos does not modulate the S-polarized light, and the S-polarized light returns to the original path. At this time, the brightness of the dark screen is Rp*Tp*0.01%+Rs*Ts. According to the contrast calculation method (Rs*Tp+Rp*0.01%) / (Tp*Rp*0.01%+Ts*Rs), it can be concluded that controlling Ts and Tp can effectively improve the contrast. Compared with the polarizing prism in the traditional projection light path, the polarizing filter 2 with the polarizing layer 21 can more effectively reduce the value of Ts, thereby obtaining a better contrast.

[0035] A compensation plate 7 is provided between the polarization filter 2 and the LCOS chip 4 for compensating for the phase difference of the LCOS polarization conversion.

[0036] By adding the compensation plate 7, it is possible to ensure that the light modulated by the LCOS chip 4 maintains a consistent phase relationship when the polarization state is converted, thereby improving the polarization conversion efficiency and image quality.

[0037] A compound eye 8 is provided on the projection light path between the light source module 1 and the imaging lens group 5 .

[0038] A compound eye 8 is provided on the projection light path between the light source module 1 and the imaging lens group 5, thereby achieving uniform illumination and improving light energy utilization.

[0039] The light source module 1 includes a blue light LED element 11, a red light LED element 12, and a green light LED element 13 arranged in parallel in sequence. The light-emitting side of the blue light LED element 11 is provided with a reflector 14 for reflecting blue light, the light-emitting side of the red light LED element 12 is provided with a first dichroic plate 15 that reflects red light and transmits blue light, and the light-emitting side of the green light LED element 13 is provided with a second dichroic plate 16 that reflects green light and transmits red and blue light.

[0040] The blue LED element 11, the red LED element 12, the green LED element 13, the reflector 14, the first dichroic filter 15, and the second dichroic filter 16 work together to provide the color foundation for the projection system. The three LED light sources are arranged side by side, allowing them to be combined into a single light panel, resulting in a simple structure and heat dissipation mechanism, facilitating modular production.

[0041] A first relay lens 17 capable of enhancing the collimation of blue light is provided on the projection light path between the reflector 14 and the first dichroic plate 15 , and a second relay lens 18 capable of enhancing the collimation of blue light and red light is provided on the projection light path between the first dichroic plate 15 and the second dichroic plate 16 .

[0042] The collimation of the light beam is enhanced by the arrangement of the first relay lens 17 and the second relay lens 18 .

[0043] A collimating lens group 19 is provided on the light-emitting side of the blue LED element 11 , the red LED element 12 , and the green LED element 13 .

[0044] The collimation of the light beam is enhanced by disposing the collimating lens group 19 .

[0045] In one embodiment, the collimating lens group 19 includes a spherical lens and an aspherical lens. After the LED light source is collimated by the spherical lens and the aspherical lens, a lens is added for light sources with a larger combined size to enhance light collimation and improve efficiency.

[0046] The utility model can be applied to head-up display and is suitable for the characteristics of ARHUD head-up display. The LCOS projector emits polarized light, and the windshield has good reflective properties for polarized light, thereby greatly increasing the utilization efficiency.

Claims

1. An LCOS projection device, characterized in that: The invention comprises a light source module (1) capable of emitting red, green and blue light beams, a polarizing filter (2) and an imaging lens (3), wherein the light source module (1), the polarizing filter (2) and the imaging lens (3) are sequentially arranged along a projection light path, an LCOS chip (4) capable of modulating the polarization state of incident light is provided on the projection light path between the polarizing filter (2) and the imaging lens (3), an imaging lens group (5) capable of imaging the incident light onto the LCOS chip (4) is provided on the projection light path between the light source module (1) and the polarizing filter (2), and a polarizing layer (21) capable of transmitting P-polarized light and reflecting S-polarized light is provided on the polarizing filter (2).

2. The LCOS projection device according to claim 1, wherein: The material of the polarizing filter (2) includes glass, and the polarizing layer (21) is coated on the surface of the polarizing filter (2) at high temperature.

3. The LCOS projection device according to claim 1, wherein: The material of the polarizing layer (21) includes plastic, and the surface of the polarizing layer (21) has a polarizing structure formed by coating or rolling.

4. The LCOS projection device according to claim 1, wherein: The LCOS chip (4) is arranged on the transmission light path of the polarizing filter (2), and the LCOS chip (4) is capable of modulating incident light into S-polarized light. The polarizing filter (2) is capable of reflecting the S-polarized light modulated by the LCOS chip (4) to the imaging lens (3). A first polarizer (61) capable of filtering P-polarized light is provided on the projection light path between the light-emitting side of the polarizing filter (2) that reflects the S-polarized light modulated by the LCOS chip (4) and the imaging lens (3).

5. The LCOS projection device according to claim 1, wherein: The LCOS chip (4) is arranged on the reflection light path of the polarizing filter (2), and the LCOS chip (4) is capable of modulating incident light into P-polarized light. The polarizing filter (2) is capable of transmitting the P-polarized light modulated by the LCOS chip (4) to the imaging lens (3). A second polarizer (62) capable of filtering the P-polarized light is provided on the projection light path between the imaging lens group (5) and the polarizing filter (2).

6. The LCOS projection device according to claim 1, wherein: A compensation plate (7) for compensating for the phase difference of LCOS polarization conversion is provided between the polarization filter (2) and the LCOS chip (4).

7. The LCOS projection device according to claim 1, wherein: A compound eye (8) is provided on the projection light path between the light source module (1) and the imaging lens group (5).

8. The LCOS projection device according to claim 1, wherein: The light source module (1) comprises a blue LED element (11), a red LED element (12), and a green LED element (13) arranged in parallel in sequence; a reflector (14) for reflecting blue light is provided on the light-emitting side of the blue LED element (11); a first dichroic plate (15) for reflecting red light and transmitting blue light is provided on the light-emitting side of the red LED element (12); and a second dichroic plate (16) for reflecting green light and transmitting red and blue light is provided on the light-emitting side of the green LED element (13).

9. The LCOS projection device according to claim 8, characterized in that: A first relay lens (17) capable of enhancing the collimation of blue light is provided on the projection light path between the reflector (14) and the first dichroic plate (15), and a second relay lens (18) capable of enhancing the collimation of blue light and red light is provided on the projection light path between the first dichroic plate (15) and the second dichroic plate (16).

10. The LCOS projection device according to claim 9, characterized in that: The light-emitting sides of the blue LED element (11), the red LED element (12), and the green LED element (13) are all provided with a collimating lens group (19).

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