Illumination light combination module, polarized light conversion module and HUD backlight system

Abstract

The utility model discloses an illumination light combination module, a polarized light conversion module and an HUD backlight system, and the illumination light combination module comprises a light source module and a collimation light combination module. The light source module comprises an LED light source with at least one color; if the light source module comprises an LED light source with one color, the collimation light combination module comprises a TIR collimation lens and a positive focus lens which are glued together; if the light source module comprises LED light sources with at least two colors, the collimation and light combination module comprises a TIR collimation lens, a light combination prism and a positive focus lens which are glued together; the polarized light conversion module comprises a polarization light splitting module, at least one front relay lens arranged in front of the polarization light splitting module along the light incidence direction, at least one rear relay lens arranged behind the polarization light splitting module along the light incidence direction, and an LCOS chip arranged behind the rear relay lens.

Description

Technical Field

[0001] This application relates to the technical field of optical devices, and particularly to an illumination light combining module, a polarized light conversion module, and an HUD backlight system. Background Art

[0002] HUD (Head Up Display) technology originally originated in the fighter aircraft field. During high-speed flight, pilots need extremely high reaction speeds and high concentration. However, the instrument systems of fighter aircraft are complex and have a huge amount of information. To avoid pilots frequently lowering their heads to check the instruments and thus being distracted, HUD technology emerged. This technology projects key flight data directly in front of the pilot's line of sight in an intuitive manner, greatly improving flight safety and efficiency.

[0003] With the continuous development of technology, HUD technology has gradually expanded from the military field to the civilian field, especially in the automotive industry. HUD technology uses the principle of optical reflection to project key data such as driving assistance information, navigation information, vehicle speed information, inspection control information, and ADAS (Advanced Driver Assistance System) information of the vehicle onto the windshield in a projected manner. In this way, during driving, the driver only needs to slightly raise their head to quickly obtain this information without having to lower their head to check the instrument panel, thereby significantly improving driving safety and convenience.

[0004] The core components of an HUD system mainly include a PGU (Picture Generation Unit), a free-form mirror (Concave Mirror), and a windshield (Windshield). Among them, the PGU module is the core of the HUD system, which is responsible for generating and projecting images. In recent years, with the continuous progress of display technology, LCOS (Liquid Crystal on Silicon) chips have gradually emerged. LCOS chips are a new type of reflective projection technology, with advantages such as high contrast, high resolution, large display screen size, small sunlight backflow problem, and low power consumption. These characteristics make LCOS chips an ideal choice for the PGU module in the HUD system, further promoting the application and development of HUD technology in the automotive industry.

[0005] An HUD (Head-Up Display) backlight system usually relies on LED light sources to meet its display requirements, and when using a backlight system based on LCOS chips, RGB (Red, Green, Blue) LEDs as backlights have become a common choice. However, in the prior art, this system faces the following two major problems:

[0006] 1. The light combining structure of RGB LED light sources is complex:

[0007] During the light combining process of RGB LED light sources, traditional technologies usually collimate RGB LED light sources by means of a combination of two lenses, and then achieve light combining through a dichroic mirror. This solution is relatively complex in structure and requires at least 6 collimating lenses and 2 dichroic mirrors to be installed. When installing the dichroic mirror, special attention also needs to be paid to its front and back directions, which undoubtedly increases the complexity and time consumption of the installation process.

[0008] 2. Limited beam utilization efficiency and PBS performance:

[0009] Before the light beam is incident on the PBS (polarizing beam splitter), a converging lens group is usually used to focus the light beam. The function of the PBS is to decompose the incident unpolarized light into two perpendicular linearly polarized lights. These linearly polarized lights enter the LCOS chip through a quarter-wave plate for modulation, and then are reflected and pass through the quarter-wave plate again, and finally reach the projection lens through the PBS to form an image. However, this solution has the problem of low light efficiency. Since the spot size of the RGB LED light source after collimation and light combining is usually much larger than the area of the LCOS chip, if the light beam is incident on the PBS in a relatively collimated state, a large amount of light will be wasted outside the LCOS chip. On the contrary, if the light beam is adjusted to a converging state to match the area of the LCOS chip, the light rays in the light beam will have different spatial solid angles, resulting in different incident angles on the PBS and possibly large incident angles. According to the design principle of optical thin films, different incident angles will affect the reflectivity / transmittance of the PBS for S light and P light, thus significantly reducing the reflectivity / transmittance and contrast of the PBS at large incident angles.

[0010] In summary, the existing HUD backlight system has obvious deficiencies in the light source combining structure and beam utilization efficiency, and these problems limit the overall performance and efficiency of the HUD system.

[0011] The content described in this background technology is only for facilitating the understanding of the relevant technologies in this field and is not regarded as an admission of the prior art. Summary of the Invention

[0012] In view of this, embodiments of the present application aim to provide an illumination light combining module, a polarized light conversion module, and an HUD backlight system. First, a TIR collimating lens is used to collimate RGB LED light sources respectively, and then a specific structure of a prism is used to combine the light rays. On the inclined surface of this prism, a blue-transmitting and red-green-reflecting film and a red-reflecting and blue-green-transmitting film are respectively deposited to ensure that the light rays can be correctly separated and combined. At the exit port of the prism, a positive focal collimating lens is configured to further optimize the beam quality. Finally, the TIR collimating lens, the coated prism, and the positive focal lens are integrated into an integral structure through precise gluing technology. Such a design can effectively protect the coated area, avoid the intrusion of impurities and dust, and ensure that the film layer is clean and flawless; and the prism light combining method ensures the stability of the light path, avoiding the problem of beam deflection; moreover, the overall structure simplifies the installation process, which can be completed only by a single installation, greatly improving the installation efficiency and convenience.

[0013] Before the light beam enters the polarization beam splitting module, collimation processing is designed and implemented to ensure that the light beam can be incident on the polarization beam splitting module at a low angle close to parallel, so as to maximize the utilization of the high light utilization rate and high contrast characteristics of the polarization beam splitting module. After the light beam leaves the polarization beam splitting module, a positive focal lens is used for focusing to ensure that when the light beam reaches the LCOS chip, the illumination area is precisely matched, avoiding the waste of light energy. After being modulated and reflected by the LCOS chip, the light beam passes through the positive focal lens again for collimation, and then returns to the polarization beam splitting module, also incident at a low angle, and finally is captured by the projection lens to complete imaging. This design not only optimizes the transmission efficiency of the light beam in the system, but also ensures the stability and improvement of the imaging quality.

[0014] In a first aspect, embodiments of the present application provide an illumination light combining module, including:

[0015] a light source module and a collimating and light combining module;

[0016] The light source module includes LED light sources of at least one color;

[0017] If the light source module includes an LED light source of one color, the collimating and light combining module includes a TIR collimating lens and a positive focal lens glued together;

[0018] If the light source module includes LED light sources of at least two colors, the collimating and light combining module includes a TIR collimating lens, a light combining prism, and a positive focal lens glued together.

[0019] Optionally, the positive focal lens is disposed at the exit end of the TIR collimating lens or the exit end of the light combining prism.

[0020] Optionally, the exit surface of the TIR collimating lens is a plane.

[0021] In a second aspect, an embodiment of the present application provides a polarized light conversion module which performs polarized light conversion on the outgoing light of the illumination combining module according to any one of the first aspect. The polarized light conversion module includes: a polarization beam splitting module, at least one front relay lens disposed in front of the polarization beam splitting module along the light incident direction, at least one rear relay lens disposed behind the polarization beam splitting module along the light incident direction, and an LCOS chip disposed behind the rear relay lens.

[0022] Optionally, the polarized light conversion module further includes a quarter-wave plate disposed between the rear relay lens and the LCOS chip, and the quarter-wave plate can rotate around its surface axis.

[0023] Optionally, the light emitted from the collimating and combining module enters the polarized light conversion module through a fly-eye lens. The size of the fly-eye lens is determined according to the size of the LCOS chip, and the beam angle range allowed to enter the fly-eye lens is calculated according to the size of the fly-eye lens.

[0024] Optionally, the focal lengths of the front relay lens and the rear relay lens are calculated according to the relationship between the size of the fly-eye lens and the size of the LCOS chip.

[0025] Optionally, the position of the LCOS chip is determined according to the focal lengths of the front relay lens and the rear relay lens.

[0026] Optionally, the polarized light conversion module further includes a linear polarizer disposed between the front relay lens and the polarization beam splitting module.

[0027] In a second aspect, an embodiment of the present application provides an HUD backlight system which includes: the illumination combining module according to any one of the first aspect, the polarized light conversion module according to any one of the second aspect, and a projection lens;

[0028] The light emitted from the glued illumination combining module enters the polarized light conversion module through a fly-eye lens at an ideal angle, is collimated by the front relay lens in the polarized light conversion module and then enters the polarization beam splitting module, and then enters the LCOS chip at an ideal area through the rear relay lens in the polarized light conversion module. After being modulated and reflected by the LCOS chip, it passes through the rear relay lens and the polarized light conversion module again, and finally the light beam is imaged through the projection lens. [[ID=!23]]

[0029] In this application, a TIR collimating lens is used to perform precise collimation processing on RGB LED light sources respectively, and then the merging of the optical paths is achieved by using the specific structure of a prism. During this process, two thin films are carefully coated on the inclined surface of the prism: one is a blue-transmitting and red-green-reflecting film, and the other is a red-reflecting and blue-green-transmitting film. These two films are responsible for the transmission and reflection of specific light waves respectively. At the output port of the prism, a positive focal lens is configured to focus the light. Finally, the TIR collimating lens, the coated prism, and the positive focal lens are integrated into a compact component through precise gluing technology. With such a design, the coating layer is effectively protected from the intrusion of impurities and dust, and at the same time, it is ensured that the light beam will not deflect during transmission, thus maintaining the purity and directivity of the light. And in the installation process, this integrated design greatly simplifies the operation steps. The entire component can be deployed with only one installation, which not only saves time but also reduces the complexity and potential errors during installation, improving the overall production efficiency and installation convenience.

[0030] Preferably, before the light beam enters the polarization beam splitter prism, a set of collimating relay lens group (front relay lens) is designed to ensure that the light beam can be accurately projected onto the PBS at a small incident angle, so as to maximize the performance advantages of the PBS. When the light exits from the PBS, a plano-convex converging lens (rear relay lens) is deployed to precisely focus the light beam, ensuring that when the light beam irradiates the LCOS chip, its illumination area is neither too large nor too small, achieving the full utilization of light energy and avoiding any form of waste. After being modulated and reflected by the LCOS chip, the light beam passes through the plano-convex converging lens again. This time, the function of the lens is to perform secondary collimation on the light beam so that it re-enters the PBS at an as parallel and small angle as possible. This design not only ensures that the light beam can enter the PBS in the best state when passing through the PBS twice but also further improves the overall performance of the system. By controlling the incident angle of the light beam, the transmittance, reflectivity, and contrast of the light beam on the PBS are successfully improved, thus making full use of the polarization beam splitting characteristics of the PBS. When the light beam first enters the LCOS chip, the rear relay lens ensures that the light beam can fully and efficiently cover the chip surface while avoiding an excessive illumination area, thereby improving the light efficiency. After the light beam is modulated and reflected back by the LCOS chip, the rear relay lens plays its collimation role again, making the light beam re-enter at a parallel and small angle that meets the requirements of the PBS, and this characteristic meets the standard of the PBS for the incident light beam.

[0031] Some other optional features and technical effects of the embodiments of this application are described below, and some can be understood by reading this article. Description of the Drawings

[0032] Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings. The elements shown are not limited by the scale shown in the drawings. The same or similar reference numerals in the drawings represent the same or similar elements, where:

[0033] Figure 1 A schematic diagram of an HUD backlight system based on an LCOS chip that can implement the embodiments of the present application is shown;

[0034] Figure 2 A schematic diagram of the structure of an illumination combining module that can implement the embodiments of the present application is shown;

[0035] Figure 3 A schematic diagram of the light emitting angle of an LED light source that can implement the embodiments of the present application is shown;

[0036] Figure 4 A schematic diagram of the principle of a TIR collimating lens that can implement the embodiments of the present application is shown;

[0037] Figure 5 A schematic diagram of the beam angle distribution after an LED light source is collimated by a TIR collimating lens that can implement the embodiments of the present application is shown;

[0038] Figure 6 A schematic diagram of optimizing the parameters of a relay lens by ZEMAX that can implement the embodiments of the present application is shown;

[0039] Figure 7 A schematic diagram of the optical path of an optimized relay lens by ZEMAX that can implement the embodiments of the present application is shown;

[0040] Figure 8 A schematic diagram of the spot distribution of an LCOS chip that can implement the embodiments of the present application is shown.

[0041] The markings in the figure are as follows: 1 - blue LED light source, 2 - green LED light source, 3 - red LED light source, 4 - first TIR collimating lens, 5 - second TIR collimating lens, 6 - third TIR collimating lens, 7 - first combining prism, 8 - second combining prism, 9 - third combining prism, 10 - positive focal lens, 11 - illumination combining module, 12 - fly-eye lens, 13 - first relay lens, 14 - second relay lens, 15 - linear polarizer, 16 - PBS polarization beam splitter, 17 - third relay lens, 18 - third relay lens, 19 - LCOS chip, 20 - polarization light conversion module, 21 - projection lens. Detailed implementation manners

[0042] In order to make the purpose, technical solutions and advantages of this application more clear, the present application is further described in detail below in conjunction with specific implementation methods and drawings. Here, the illustrative implementation methods and descriptions of this application are used to explain this application, but are not intended to limit this application.

[0043] As used herein, the term "including" and its variations represent open inclusion, i.e., "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based at least in part on." The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "first," "second," etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0044] In the embodiment of the present application, a HUD backlight system based on an LCOS chip is provided. Figure 1 . Figure 1 FIG. 1 shows a schematic diagram of a HUD backlight system based on an LCOS chip that can implement an embodiment of the present application. Figure 1 The HUD backlight system based on the LCOS chip shown includes an illumination light combining module 11, a fly-eye lens 12, a polarization light conversion module 20, and a projection lens 21. The polarization light conversion module 20 includes a first relay lens 13, a second relay lens 14, a linear polarizer 15, a PBS polarization beam splitter 16, a third relay lens 17, a quarter-wave plate 18, and an LCOS chip 19.

[0045] The following is a detailed description of the lighting light combining module 11, see Figure 2 . Figure 2 FIG. 1 shows a schematic diagram of a lighting light combining module structure that can implement the embodiment of the present application. Figure 2 The lighting light combining module shown includes: a light source module and a collimating light combining module. The light source module includes an LED light source of at least one color. Figure 2 The exemplary light source module in the embodiment shown includes: a blue LED light source 1, a green LED light source 2 and a red LED light source 3. The collimating light combining module includes a total internal reflection (TIR) collimating lens, a light combining prism and a positive focus lens. Figure 1In the exemplary collimating and combining optical module in the illustrated embodiment, it includes: a first TIR collimating lens 4, a second TIR collimating lens 5, a third TIR collimating lens 6, a combining prism 7 (the first combining prism), a combining prism 8 (the second combining prism), a combining prism 9 (the third combining prism), and a positive focal length lens 10. Preferably, the combining prism 7 and the combining prism 9 are exactly the same in size and shape. Of course, the combining prism 7 and the combining prism 9 may also be different in size and shape. The combining prism 8 is a parallelogram prism. The positive focal length lens 10 is a plano-convex collimating lens.

[0046] In some embodiments, if the light source module only includes an LED light source of one color, then the collimating module only includes a TIR collimating lens corresponding to the light source and a positive focal length lens. The TIR collimating lens and the positive focal length lens are glued together.

[0047] In some other embodiments, if the light source module includes LED light sources of two colors, then the collimating module includes TIR collimating lenses corresponding to the two-color LED light sources, two combining prisms, and a positive focal length lens. The TIR collimating lenses, the combining prisms, and the positive focal length lens are glued together.

[0048] The LED light source usually has a luminous angle of about 120°, see Figure 3 . Figure 3 shows a schematic diagram of the luminous angle of the LED light source that can implement the embodiment of the present application. As Figure 3 shown, when the LED light source emits light, it will generate a large-range and multi-directional light beam. Therefore, collimation processing is required before using the LED light source. For RGB (red, green, blue) LED light sources, the design principle of the TIR collimating lens is shown in Figure 4 , Figure 4 shows a schematic diagram of the principle of the TIR collimating lens that can implement the embodiment of the present application. As Figure 3 shown, the light beam with a beam angle less than 60° will pass through the central position of the TIR collimating lens and be collimated and emitted after refraction; while the light with an angle greater than 60° is reflected by the side of the TIR collimating lens, and also realizes collimated emission. The exit surface of the TIR collimating lens is designed as a plane to facilitate gluing with the subsequent combining prism or positive focal length lens. After being collimated by the TIR collimating lens, the light beam has a spot diameter of about 15 mm, and the luminous angle of the light beam at 50% energy is about 10°, see Figure 5 .

[0049] Figure 5 shows a schematic diagram of the beam angle distribution of the LED light source collimated by the TIR collimating lens that can implement the embodiment of the present application. As Figure 5As shown, the blue and green light beams collimated by the TIR collimating lens will first pass through the blue-transmitting, red-and-green-reflecting film layer (film layer 7) for light combination, and then pass through the red-reflecting, blue-and-green-transmitting film layer (film layer 8) to combine with the red light, ultimately forming a mixed light beam. It should be noted that during this process, the three light beams must remain coaxial to ensure color consistency in the projected image.

[0050] However, the light beam from the LED light source after collimation will diverge slightly as the transmission distance increases. Considering that the size of the collimated light spot cannot be too large, according to the principle of conservation of optical extension, the TIR collimating lens cannot fully collimate the LED light source. Therefore, at the exit end of the prism after light combination, the embodiment of the present application provides a positive focus lens 10 to perform secondary collimation on the light beam that has been combined and collimated. It should be noted that if the light source module only includes an LED light source of one color, then the positive focus lens 10 is provided at the exit end of the TIR collimating lens.

[0051] It should be noted that TIR collimating lenses are widely used in lighting light-combining modules. However, TIR collimating lenses such as collimating reflector designs or plano-convex collimating lenses can also be considered. Light-combining prisms are key components in lighting light-combining modules. Traditionally, light is combined by coating the surface. However, to simplify the manufacturing process and reduce costs, a polygonal prism light-combining design is being considered. This design does not require coating, but instead guides the light to combine through the different angles and shapes of the prism.

[0052] In addition, the material selection of the collimating lens and prism can also be more flexible. In addition to the traditional K9 glass, PC (polycarbonate) or other suitable transparent materials can also be considered.

[0053] The collimation of the collimated light beam output from the collimating light combining module is extremely important, because only when the light enters the compound eye lens in a nearly parallel state can each micro unit of the compound eye lens produce a consistent beam separation effect on the incident light. If the light beam is incident at a large angle, the angle of the light emitted from each micro unit of the compound eye will vary with the angle of incidence, resulting in a decrease in the uniformity of the light spot formed at the edge of the LCOS chip after passing through the relay lens, and may be accompanied by the generation of secondary light spots, thereby significantly reducing the effective utilization rate of light energy. The aspect ratio of the sub-lens of the compound eye lens is designed according to the size of the LCOS chip. In the embodiment of the present application, the exemplary compound eye lens has a length of 1.22mm, a width of 0.62mm, and a thickness of 5.3mm. Based on the above-mentioned size parameters of the compound eye lens, the angle range of the light beam allowed to be incident on the compound eye lens can be calculated, so as to ensure that the angle meets the requirements of the compound eye lens when designing the lighting light combining module. Ideally, the angle range of the light beam incident on the compound eye lens should be less than 13.1°×6.7°.

[0054] The collimated light beam that has been shaped and homogenized by the compound eye lens. Based on the size relationship between the compound eye lens and the LCOS chip, the focal length of the relay lens can be calculated. Exemplarily in the embodiments of this application, the focal length of the relay lens is 30 mm, and the position of the LCOS chip is determined according to the focal length of the relay lens.

[0055] It should be noted that the polarization beam splitting module in the polarized light conversion module can be a PBS polarization beam splitter, and devices such as polarizing films, phase retardation films, mirrors, and beam splitters that can achieve polarization beam splitting are also applicable. In the embodiments of this application, the PBS polarization beam splitter is used as an example for illustration, but no specific limitation is made. The surface of the PBS polarization beam splitter is usually coated with a dielectric film. According to the principles of optical thin film design, at different incident angles, the reflectivity / transmittance of the PBS for S-polarized light and P-polarized light will be different. When the incident beam angle is relatively large, the reflectivity and / or transmittance and contrast of the PBS will decrease significantly. If a single lens with a focal length of 30 mm is used as the relay, the light beam entering the PBS often has a relatively large convergence angle, thus affecting the performance of the PBS. Therefore, in the embodiments of this application, this lens is split into three relay lenses, the first front relay lens 13 (front relay lens), the second front relay lens 14 (front relay lens), and the rear relay lens 17. And the ZEMAX software is used for design to obtain the position and surface type parameters of the three relay lenses. See Figure 6 and Figure 7 。 Figure 6 Fig. shows a schematic diagram of optimizing the parameters of the relay lens in ZEMAX that can implement the embodiments of this application. Figure 7 Fig. shows a schematic diagram of the optical path of the ZEMAX-optimized relay lens that can implement the embodiments of this application.

[0056] In some embodiments, a linear polarizer can be set in front of the PBS polarization beam splitter, and a quarter-wave plate that can rotate around its surface axis can be set between the rear relay lens and the LCOS chip. In an actual system, due to the modulation of the incident light polarization state by the LCOS device may deviate from the ideal state, resulting in residual P-polarization state energy in the bright-state outgoing light beam, and the S-polarization state light energy in the dark-state outgoing light beam increases, thus affecting the contrast of the system. By rotating the quarter-wave plate in combination with the linear polarizer, we can effectively improve the contrast of the system projection screen.

[0057] It should be noted that the compound eye lens 12 and the relay lens 13 in the polarized light conversion module are usually used as a lens combination. It is also possible to consider using a beam reduction and collimation optical path, such as a Kepler system or a Galileo system. At a position close to the LCOS chip, a plano-convex converging lens (rear relay lens) is usually used to focus the light beam onto the chip. To provide more extensive design options, other types of lenses can be considered to replace the plano-convex converging lens as long as these lenses can achieve the same function.

[0058] Before the light beam enters the PBS polarization beam splitter, through a reasonably designed beam shrinking and collimating optical path, the light beam can be collimated and shrunk to an area suitable for the LCOS chip. In this way, there is no need to set a positive focal length lens (post-relay lens) between the PBS polarization beam splitter and the LCOS chip, thus simplifying the optical path structure and reducing the cost.

[0059] After the simulation by the ZEMAX software, the picture presented on the LCOS chip shows excellent clarity and uniformity. For the specific effect, please refer to Figure 8 , Figure 8 which shows a schematic diagram of the spot distribution of the LCOS chip capable of implementing the embodiments of the present application. As Figure 8 shown, when the light beam passes through the modulation and reflection of the LCOS chip, it passes through the quarter-wave plate and enters the positive focal length lens again. Under the action of the positive focal length lens, the light beam is effectively collimated and then enters the PBS polarization beam splitter for the second time. In the PBS, the light beam is reflected and directed to the projection lens, finally completing the high-quality imaging process.

[0060] In this document, multiple embodiments of the present application are described. However, for the sake of brevity, the descriptions of the embodiments are not exhaustive, and the same or similar features or parts between the embodiments may be omitted. In this document, "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean applicable to at least one embodiment or example according to the present application, rather than all embodiments. The above terms do not necessarily refer to the same embodiment or example. Without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0061] The exemplary systems and methods of the present application have been specifically shown and described with reference to the above embodiments, which are only examples of the best mode for implementing the systems and methods. Those skilled in the art can understand that various changes can be made to the embodiments of the systems and methods described here when implementing the systems and / or methods without departing from the spirit and scope of the present application defined in the appended claims.

Claims

1. A lighting light-combining module, characterized in that, Comprising: A light source module and a collimating and combining light module; The light source module includes at least one color of LED light source; If the light source module includes one color of LED light source, the collimating and combining light module includes a TIR collimating lens and a positive focal length lens glued together; If the light source module includes at least two colors of LED light sources, the collimating and combining light module includes a TIR collimating lens, a combining prism and a positive focal length lens glued together.

2. The lighting light-combining module according to claim 1, characterized in that, The positive focal length lens is arranged at the exit end of the TIR collimating lens or the exit end of the combining prism.

3. The lighting light-combining module according to any one of claims 1 to 2, characterized in that, The exit surface of the TIR collimating lens is a plane.

4. A polarized light conversion module, characterized in that, The polarization conversion module performs polarization conversion on the exit light of the illumination combining light module according to any one of claims 1 to 3. The polarization conversion module includes: a polarization beam splitting module, at least one front relay lens arranged in front of the polarization beam splitting module along the light incident direction, at least one rear relay lens arranged behind the polarization beam splitting module along the light incident direction, and an LCOS chip arranged behind the rear relay lens.

5. The polarization conversion module according to claim 4, wherein The polarization conversion module further includes a quarter-wave plate arranged between the rear relay lens and the LCOS chip, and the quarter-wave plate can rotate around its surface axis.

6. The polarization conversion module according to claim 4, wherein The light exiting from the collimating and combining light module enters the polarization conversion module through a fly-eye lens. The size of the fly-eye lens is determined according to the size of the LCOS chip, and the beam angle range allowed to enter the fly-eye lens is calculated according to the size of the fly-eye lens.

7. The polarization conversion module according to claim 6, wherein According to the relationship between the size of the fly-eye lens and the size of the LCOS chip, the focal lengths of the front relay lens and the rear relay lens are calculated.

8. The polarization conversion module according to claim 7, wherein The position of the LCOS chip is determined according to the focal lengths of the front relay lens and the rear relay lens.

9. The polarization conversion module according to claim 4, wherein, The polarization conversion module further includes a linear polarizer arranged between the front relay lens and the polarization beam splitting module.

10. An HUD backlight system, characterized in that, The HUD backlight system includes: the illumination combining light module according to any one of claims 1 to 3, the polarization conversion module according to any one of claims 4 to 9, and a projection lens; The light exiting from the glued illumination combining light module enters the polarization conversion module at an ideal angle through a fly-eye lens, is collimated by the front relay lens in the polarization conversion module and then enters the polarization beam splitting module, and then enters the LCOS chip at an ideal area through the rear relay lens in the polarization conversion module. After being modulated and reflected by the LCOS chip, it passes through the rear relay lens and the polarization conversion module again, and finally the light beam is imaged through the projection lens.

Images