Optical module and head-up display

Abstract

The present application provides an optical module and a head-up display. The optical module comprises: an image generating unit configured to emit image light with image information; a reflecting component configured to receive the image light emitted by the image generating unit and reflect the image light to outside of the optical module; and a light blocking component arranged between an image light emitting side of the image generating unit and the reflecting component and configured to allow the image light to pass through and at least partially block light from outside of the optical module from entering the image generating unit. By arranging the light blocking component between the image generating unit and the reflecting component, at least part of the light (e.g. sunlight) from outside of the optical module can be blocked from entering the image generating unit, thereby reducing the risk of the image generating unit being damaged by backflow of sunlight, and the optical module is suitable for use in a windshield type head-up display and an augmented reality type head-up display.

Description

Optical modules and head-up displays Technical Field

[0001] This invention relates to the field of vehicle display technology, and in particular to an optical module and a head-up display. Background Technology

[0002] A head-up display (HUD) is a driver assistance system that is becoming increasingly widely used in in-vehicle electronic systems. In-vehicle HUDs can project important driving information such as speed and navigation onto the windshield or imaging window in front of the driver through a reflective optical system, allowing the driver to see important driving information such as speed and navigation without looking down, thereby improving driving safety and providing the driver with a better driving experience.

[0003] Currently, most in-vehicle head-up displays (HUDs) employ the optical principle of concave lens magnification projection. Figure 7 shows an existing in-vehicle HUD 200, which includes an optical engine 210 and a reflector assembly 220. The reflector assembly 220 contains at least one concave lens. The optical engine 210 emits image light carrying image information to the reflector assembly. After reflection and magnification, the image light is projected onto the windshield of the car. While the concave lens in the reflector assembly reflects and diffuses the image light, resulting in a larger image on the windshield, when sunlight enters the HUD 200, it also converges the sunlight onto the optical engine 210. This causes a significant increase in the temperature of the optical engine 210, affecting its imaging quality and potentially leading to overheating and damage. This is known as sunlight backflow. Furthermore, the higher the magnification of the reflector assembly 220 (concave lens), the greater the impact of sunlight backflow.

[0004] The content of the background section is merely the technology known to the inventor and does not necessarily represent the prior art in this field. Summary of the Invention

[0005] To address one or more deficiencies in the prior art, the present invention provides an optical module comprising:

[0006] The image generation unit is configured to emit image light carrying image information;

[0007] A reflective component configured to receive image light emitted by the image generation unit and reflect it to the outside of the optical module; and

[0008] A light-blocking component is disposed between the light-emitting side of the image generating unit and the reflective component, and configured to allow the image light to pass through while at least partially blocking light from outside the optical module from entering the image generating unit. The light-blocking component includes multiple structural layers stacked along the direction of the image light, wherein the refractive index of at least two adjacent structural layers increases along the direction of the image light. The multiple structural layers include a microstructure film layer, wherein the microstructure film layer is closest to the image generating unit, and the side of the microstructure film layer facing the image generating unit is configured with a sawtooth structure.

[0009] According to one aspect of the invention, the serrated structure includes one or more teeth, said teeth including a vertical surface and an inclined surface.

[0010] According to one aspect of the present invention, the plurality of structural layers further include a glass substrate layer, a polarization selection layer and / or a bandpass filter layer;

[0011] The bandpass region of the bandpass filter layer is the visible light band;

[0012] The image light is S-polarized light, and the polarization selection layer is configured to transmit S-polarized light and filter P-polarized light; or the image light is P-polarized light, and the polarization selection layer is configured to transmit P-polarized light and filter S-polarized light.

[0013] According to one aspect of the invention, the refractive index of a structural layer located upstream of and adjacent to the glass substrate layer is less than that of the glass substrate layer.

[0014] According to one aspect of the present invention, the microstructure film layer is adjacent to the glass substrate layer, and the polarization selection layer and / or the bandpass filter layer are disposed on the side of the glass substrate layer opposite to the microstructure film layer.

[0015] According to one aspect of the invention, the polarization selection layer and / or bandpass filter layer are disposed between the microstructure film layer and the glass substrate layer.

[0016] According to one aspect of the present invention, the polarization selection layer and the bandpass filter layer are respectively disposed on both sides of the glass substrate layer.

[0017] According to one aspect of the present invention, the angle between the light-emitting surface of the light-blocking component and the light-emitting surface of the image generating unit is 10-50°.

[0018] According to one aspect of the invention, the refractive index of the plurality of structural layers increases sequentially along the direction of the image light.

[0019] According to one aspect of the invention, the projected area of ​​the light-emitting surface of the light-blocking component on the image generating unit is larger than the area of ​​the light-emitting surface of the image generating unit.

[0020] According to one aspect of the present invention, the reflective assembly includes a first reflector and a second reflector, the first reflector being configured to receive the image light transmitted by the light-blocking assembly and reflect the image light toward the second reflector; the second reflector being configured to receive the image light reflected from the first reflector and reflect the image light toward a predetermined direction.

[0021] According to one aspect of the invention, the first reflecting mirror is a curved mirror or a plane mirror; the second reflecting mirror is a curved mirror.

[0022] The present invention also provides a head-up display, including the optical module described above.

[0023] Compared to existing technologies, embodiments of the present invention provide an optical module and a head-up display. By placing a light-blocking component between the image generation unit and the reflective component, at least a portion of light rays (e.g., sunlight) from outside the optical module can be prevented from incident on the image generation unit, thereby reducing the risk of the image generation unit being burned out by sunlight backflow. Specifically, by setting at least two adjacent structural layers in the multiple structural layers of the light-blocking component to have a refractive index that increases along the direction of image light, when sunlight enters a lower refractive index structural layer from a higher refractive index structural layer, if the angle of incidence of sunlight is greater than a corresponding critical angle, the sunlight will be reflected and will not enter the lower refractive index structural layer, nor will it enter the image generation unit. By setting the microstructure film layer to be the closest among the multiple structural layers to the image generation unit, when sunlight exits from the sawtooth structure of the microstructure film layer, if the angle of incidence of sunlight is greater than a corresponding critical angle, the sunlight will be reflected and will not reach the image generation unit. By setting the side of the microstructure film layer facing the image generation unit to a sawtooth structure, the light-blocking component can intercept (reflect) more sunlight. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0025] Figure 1 shows a schematic diagram of an optical module according to an embodiment of the present invention;

[0026] Figure 2 shows another schematic diagram of an optical module according to an embodiment of the present invention;

[0027] Figure 3 shows a schematic diagram of a light-blocking component according to an embodiment of the present invention;

[0028] Figure 4 shows a schematic diagram of a light-blocking component according to another embodiment of the present invention;

[0029] Figures 5a-5d respectively show schematic diagrams of different structural layers of the light-blocking component in the embodiment shown in Figure 3 blocking sunlight;

[0030] Figure 6 shows a schematic diagram of the microstructure film layer and glass substrate layer of the light-blocking component in the embodiment shown in Figure 3, which intercept sunlight.

[0031] Figure 7 shows a schematic diagram of an existing in-vehicle head-up display. Detailed Implementation

[0032] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0037] The embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0038] Currently, mass-produced automotive head-up displays are gradually evolving from windshield-type head-up displays (W-HUD) to augmented reality head-up displays (AR-HUD). The virtual image distance (VID) of windshield-type head-up displays is typically between 1.9 and 5 meters, and the magnification is generally no more than 12 times. In contrast, the virtual image distance of augmented reality head-up displays is generally over 7 meters, and the magnification can reach 20-30 times. Augmented reality head-up displays have a longer projection distance and a greater magnification than windshield-type head-up displays, thus making the problem of sunlight backflow more serious.

[0039] In related technologies, there are three main solutions to prevent sunlight backflow:

[0040] Option 1 involves setting an S-polarization film on the reflective lens. The polarization film can transmit image light emitted by the optical engine (which is generally S-polarized light) and S-polarized light from sunlight, while absorbing P-polarized light from sunlight. This method can filter out about 40% of the energy from external sunlight. However, this is relatively low and is only suitable for windshield-type head-up displays with small field of view and close-range projection. It is difficult to achieve a good effect in preventing sunlight backflow in windshield-type head-up displays with large field of view, medium to long-range projection, and augmented reality head-up displays.

[0041] Option 2 involves placing a polarizing film on the dust cover (located downstream of the reflector) and coating a filter film on the surface of the reflector. The filter film is used to filter infrared and / or ultraviolet light from sunlight. This method can filter out approximately 68% of the energy of external sunlight and is suitable for windshield-type head-up displays with a large field of view and medium projection distance. However, it is difficult to effectively prevent sunlight backflow in augmented reality head-up displays. Moreover, the dust covers of augmented reality head-up displays are generally large, resulting in a large coating area and high cost. In addition, the reflector in augmented reality head-up displays is mostly a curved reflector, which is difficult to process and can introduce color distortion problems.

[0042] Option 3 uses a sunlight sensor to detect the angle of sunlight incidence. By testing and calibrating the angle at which sunlight backflow occurs, measures such as reducing the optical engine's operating power or shutting it down are taken when sunlight backflow occurs. This method can prevent sunlight backflow from burning out the optical engine and is applicable to windshield-type head-up displays and augmented reality head-up displays. However, the measures taken to prevent sunlight backflow (reducing the optical engine's operating power, shutting it down, etc.) do not reduce the energy of sunlight entering the optical engine and severely affect the user experience.

[0043] Figure 1 shows a schematic diagram of an optical module 100 according to an embodiment of the present invention, Figure 2 shows another schematic diagram of an optical module 100 according to an embodiment of the present invention, and Figure 3 shows a schematic diagram of a light-blocking component 130 according to an embodiment of the present invention. The following is a detailed description in conjunction with Figures 1 to 3.

[0044] As shown in Figures 1 and 2, the optical module 100 includes an image generation unit 110, a reflective component 120, and a light-blocking component 130. The image generation unit 110 is configured to emit image light carrying image information. The image generation unit 110 can be, for example, a projection optical engine, including but not limited to LCOS (Liquid Crystal on Silicon), LCD (Lasercladding deposition), and DLP (Digital Light Processing) projection optical engines. The reflective component 120 is configured to receive the image light emitted by the image generation unit 110 and reflect the image light to the outside of the optical module 100.

[0045] As shown in Figures 1 and 2, the light-blocking component 130 is disposed between the light-emitting side of the image generating unit 110 and the reflective component 120. The distance between the light-blocking component 130 and the image generating unit 110, and the distance between the light-blocking component 130 and the reflective component 120, can be set according to the position of each component in the head-up display; this embodiment does not impose any limitations on this. The light-blocking component 130 is configured to allow image light to pass through and at least partially block light rays (e.g., sunlight) from outside the optical module 100 from entering the image generating unit 110. The location of the light-blocking component 130 is where sunlight converges when sunlight is reversed, and the area of ​​the beam is small. Therefore, only a small light-blocking component 130 is needed to achieve effective light interception, greatly saving costs. As shown in Figures 1 and 3, the light-blocking component 130 includes multiple structural layers 131, which are stacked along the direction of image light, wherein the refractive index of at least two adjacent structural layers 131 increases along the direction of image light. The multiple structural layers 131 include a microstructure film layer 132. Among the multiple structural layers 131, the microstructure film layer 132 is closest to the image generation unit 110, and the side of the microstructure film layer 132 facing the image generation unit 110 is configured with a sawtooth structure 1321.

[0046] When light travels from a medium with a higher refractive index to a medium with a lower refractive index, if the angle of incidence of the light is greater than the corresponding critical angle (the size of the critical angle is related to the medium material), the light will be reflected and will not enter the medium with a lower refractive index. Therefore, by setting at least two adjacent structural layers 131 of the plurality of structural layers 131 to have an increased refractive index along the direction of the image light, and by setting the microstructure film layer 132 to be the closest to the image generation unit 110 among the plurality of structural layers 131, the light blocking component 130 can totally reflect at least part of the sunlight when sunlight travels from the structural layer 131 with a higher refractive index to the structural layer 131 with a lower refractive index, or when sunlight enters the air from the sawtooth structure 1321 of the microstructure film layer 132, thereby reducing the risk of the image generation unit 110 being burned out by backflow of sunlight.

[0047] According to one embodiment of the present invention, as shown in FIG3, the sawtooth structure 1321 may include multiple teeth, each tooth including a vertical surface 1322 and an inclined surface 1323, wherein the angle of the inclined surface 1323 can be set according to the actual reflection angle requirements (how the inclined surface 1323 reflects sunlight will be described in detail later). FIG4 shows a schematic diagram of a light-blocking component 130 according to another embodiment of the present invention. For example, as shown in FIG4, the sawtooth structure 1321 may also include one of the teeth. The number of teeth included in the sawtooth structure 1321 can be set according to actual needs. When the number of teeth is small, the thickness of the microstructure film layer 132 and the light-blocking component 130 is large. By increasing the number of teeth, the thickness of the microstructure film layer 132 and the light-blocking component 130 can be effectively reduced.

[0048] The image light emitted by the image generation unit 110 is generally S-polarized light, which can be recognized by the human eye (visible light). Sunlight can be divided into S-polarized light and P-polarized light according to its polarization state, and into ultraviolet light, visible light, infrared light, etc. according to its wavelength.

[0049] According to an embodiment of the present invention, as shown in FIG. 3, the plurality of structural layers 131 may further include a glass substrate layer 133, a polarization selection layer 134, and / or a bandpass filter layer 135. The glass substrate layer 133, the polarization selection layer 134, and the bandpass filter layer 135 may be selected and arranged as needed. The refractive index of the structural layer 131 located upstream of the glass substrate layer 133 (distinguished by the direction of image light emission) and adjacent to the substrate glass layer is less than that of the glass substrate layer 133, so that the structural layer 131 can totally reflect at least a portion of the sunlight when sunlight enters the structural layer 131 upstream of the glass substrate layer 133.

[0050] In this embodiment, the image light emitted by the image generation unit 110 is S-polarized light. The polarization selection layer 134 is configured to transmit S-polarized light and filter P-polarized light, so that the polarization selection layer 134 can transmit the image light and filter the P-polarized light in sunlight. The polarization selection layer 134 can be a polarizer or can be deposited on the surface of other structural layers 131 (e.g., glass substrate layer 133) by means of a coating. Compared with coating on curved surfaces, the surface of the glass substrate layer 133 is flat, which makes the processing easier and lower in cost. In other embodiments, the image light emitted by the image generation unit 110 can also be P-polarized light, and accordingly, the polarization selection layer 134 is configured to transmit P-polarized light and filter S-polarized light.

[0051] The bandpass region of the bandpass filter layer 135 can be configured to the visible light band. The bandpass filter can transmit the image light and has little impact on the brightness of the image light. The bandpass filter can also reflect infrared and ultraviolet light from sunlight, further reducing the risk of the image generation unit 110 being burned out by backflow of sunlight. The bandpass filter layer 135 can be a bandpass filter or it can be deposited on the surface of other structural layers 131 (e.g., glass substrate layer 133) by means of a coating. Compared with coating on curved surfaces, the surface of the glass substrate layer 133 is flat, which makes it easier to process and lowers the cost.

[0052] In some embodiments, the microstructure film layer 132 is adjacent to the glass substrate layer 133 (the glass substrate layer 133 is located downstream of the microstructure film layer 132, with upstream and downstream distinguished by the image light emission direction). The polarization selection layer 134 and / or the bandpass filter layer 135 are disposed on the side of the glass substrate layer 133 facing away from the microstructure film layer 132. For example, in the embodiment shown in FIG3, the microstructure film layer 132, the glass substrate layer 133, the polarization selection layer 134, and the bandpass filter layer 135 are stacked sequentially along the direction of image light. In some embodiments, the polarization selection layer 134 and / or the bandpass filter layer 135 may be disposed between the microstructure film layer 132 and the glass substrate layer 133. For example, the light blocking component 130 does not have a bandpass filter layer 135, and the microstructure film layer 132, the polarization selection layer 134, and the glass substrate layer 133 are stacked sequentially along the direction of image light. In some embodiments, the polarization selection layer 134 and the bandpass filter layer 135 are respectively disposed on both sides of the glass substrate layer 133. For example, the microstructure film layer 132, the polarization selection layer 134, the glass substrate layer 133, and the bandpass filter layer 135 are stacked sequentially along the direction of the image light.

[0053] Figures 5a-5d show schematic diagrams of different structural layers 131 of the light-blocking component 130 in the embodiment shown in Figure 3, respectively, for blocking sunlight. The principle and function of the light-blocking component 130 will be explained below with reference to Figures 5a-5d. When sunlight enters the light-blocking component 130, as shown in Figure 5a, the first stage of interception is performed by the bandpass filter layer 135 to filter out most of the energy in the sunlight and reduce the difficulty of subsequent light interception. Specifically, the bandpass filter layer 135 can transmit visible light in sunlight and reflect infrared light and ultraviolet light in sunlight. Among them, infrared light and ultraviolet light account for about 68% of the energy of sunlight.

[0054] When sunlight (visible light) passes through the bandpass filter layer 135, as shown in Figure 5b, it undergoes a second interception by the polarization selection layer 134. The polarization selection layer 134 can transmit S-polarized light in the sunlight (visible light) and filter P-polarized light in the sunlight (visible light). The polarization selection layer 134 can reduce the amount of sunlight (visible light) entering the subsequent system by more than 40%. Therefore, the polarization selection layer 134 can intercept more than 40% of the sunlight (visible light) energy.

[0055] When sunlight (P-polarized light) passes through the polarization selection layer 134, as shown in Figure 5c, it is intercepted by the glass substrate layer 133 as a third layer. The glass substrate layer 133 can reflect at least part of the sunlight. Specifically, the refractive index N1 of the glass substrate layer 133 is greater than the refractive index N2 of the microstructure film layer 132. The critical angle θ0 for sunlight to enter the microstructure film layer 132 from the glass substrate layer 133 is arcsin(N2 / N1). When sunlight enters the microstructure film layer 132 from the glass substrate layer 133, sunlight with an incident angle greater than the critical angle θ0 (such as sunlight with an incident angle of θ1 in Figure 5c) will not pass through the glass substrate layer 133, but will be totally reflected out of the glass substrate layer 133. Sunlight with an incident angle less than the critical angle θ0 is refracted into the microstructure film layer 132.

[0056] When sunlight passes through the glass substrate layer 133, as shown in Figure 5d, it is intercepted by the microstructure film layer 132 as a fourth layer. The microstructure film layer 132 can reflect at least part of the sunlight. Specifically, the refractive index N2 of the microstructure film layer 132 is greater than the refractive index N3 of air (N3 = 1). The critical angle θ2 = arcsin(N2) for sunlight to enter the air from the inclined surface 1323 of the teeth of the microstructure film layer 132 is when sunlight enters the air. When sunlight enters the air from the inclined surface 1323 of the teeth of the microstructure film layer 132, sunlight with an incident angle greater than the critical angle θ2 (for example, sunlight with an incident angle of θ3 in Figure 5c) will not pass through the microstructure film layer 132, but will be reflected out from the microstructure film layer 132. Sunlight with an incident angle less than the critical angle θ2 is refracted into the air by the inclined surface 1323.

[0057] As shown in Figures 5c, 5d, and 6, the light reflected by the total internal reflection of the glass substrate layer 133 is light that travels from the glass substrate layer 133 to the microstructure film layer 132 at a relatively large incident angle (i.e., the portion of light incident from the left half of the first reflector 121). The light reflected by the sawtooth structure 1321 of the microstructure film layer 132 is light that travels from the light blocking component 130 at a relatively small incident angle (i.e., the portion of light incident from the right half of the first reflector 121) and enters the air from the inclined surface 1323 of the teeth of the microstructure film layer 132 at a relatively large incident angle. These two processes complement each other and can block most of the light from outside the optical module 100, especially the portion of light incident from the left and right halves of the first reflector 121. In addition, by selecting materials with appropriate refractive indices to fabricate the glass substrate layer 133 and the microstructure film layer 132, the critical angles θ1 and θ2 can be narrowed, further improving the light blocking efficiency of the light blocking component 130 in blocking light from outside the optical module 100.

[0058] According to an embodiment of the present invention, as shown in FIG2, the angle between the light-emitting surface of the light-blocking component 130 and the light-emitting surface of the image generating unit 110 is 10-50°. As shown in FIG6, when sunlight is reflected by the reflector 120 to the light-blocking component 130 and the image generating unit 110, it is in a converging state. That is to say, the direction of sunlight from the left and right halves of the first reflector 121 to the image imaging unit 110 is opposite (the left and right halves of the first reflector 121 in FIG6 correspond to the upper and lower halves of the first reflector 121 in FIG1, respectively). By tilting the light-blocking component 130 at a certain angle, the light-blocking efficiency of the light-blocking component 130 can be improved, and the risk of the image generating unit 110 being burned by sunlight backflow can be reduced.

[0059] Specifically, as shown in Figure 6, the glass substrate layer 133 can totally reflect at least a portion of the sunlight incident on the image generation unit from the left half of the first reflector 121, and the microstructure film layer 132 can totally reflect at least a portion of the sunlight incident on the image generation unit from the right half of the first reflector 121. By tilting the light-blocking component 130, more sunlight (especially sunlight incident on the image generation unit from the left half of the first reflector 121) can be totally reflected from the glass substrate layer 133 at an incident angle greater than the critical angle θ0, and more sunlight (especially sunlight incident on the image generation unit from the right half of the first reflector 121) can be totally reflected from the sawtooth structure 1321 of the microstructure film layer 132 at an incident angle greater than the critical angle θ2. This allows the light-blocking component 130 to more effectively block sunlight from entering the image generation unit 110, reducing the risk of the image generation unit 110 being burned by backflow of sunlight.

[0060] According to an embodiment of the present invention, as shown in FIG3, the refractive index of the plurality of structural layers 131 increases sequentially along the image light emission direction to improve the light blocking component 130's interception efficiency of light from outside the optical module 100. Specifically, when light (sunlight) from outside the optical module 100 enters another structural layer 131 from one structural layer 131, at least a portion of the light is totally reflected.

[0061] According to one embodiment of the present invention, the projected area of ​​the light-emitting surface of the light-blocking component 130 on the image generating unit 110 (projected in reverse along the image light) is larger than the area of ​​the light-emitting surface of the image generating unit 110, so that the light-blocking component 130 can block more sunlight, reduce the possibility that sunlight will directly enter the image generating unit 110 without being filtered by the light-blocking component 130, and reduce the probability of sunlight entering the image generating unit 110.

[0062] According to one embodiment of the present invention, as shown in FIG1, the reflective assembly 120 includes a first reflector 121 and a second reflector 122, with the first reflector 121 located upstream of the second reflector 122. The first reflector 121 is configured to receive image light transmitted by the light-blocking assembly 130 and reflect the image light towards the second reflector 122. The second reflector 121 is configured to receive image light reflected from the first reflector and reflect the image light in a predetermined direction.

[0063] According to an embodiment of the present invention, as shown in Figures 2 and 6, the first reflector can be a curved mirror or a plane mirror, and the second reflector can be a curved mirror. By using a curved mirror as the second reflector, sunlight can be concentrated when reflected by the reflector 120 to the light-blocking assembly 130 and the image generation unit 110, which is beneficial for the light-blocking assembly 130 to block sunlight.

[0064] Embodiments of the present invention also provide a head-up display. The head-up display includes the optical module 100 as described above.

[0065] Windshield-type head-up displays have a lower magnification, resulting in a relatively milder problem with sunlight backflow. This can be effectively addressed by using solutions in related technologies to intercept P-polarized light, infrared light, and ultraviolet light. Augmented reality head-up displays have a magnification 3-5 times that of windshield-type displays. Even after intercepting P-polarized light, infrared light, and ultraviolet light from sunlight using related technologies, a significant amount of sunlight energy still converges into the optical engine, potentially causing overheating and damage. This invention provides an optical module 10 that, by placing a light-blocking component 130 between the image generation unit 110 and the reflection component 120, can effectively intercept infrared light, ultraviolet light, P-polarized light (or S-polarized light), and sunlight at a certain incident angle. It has a higher interception efficiency for external light and can effectively prevent the image generation unit 110 from burning out due to sunlight backflow. This module is suitable for both windshield-type and augmented reality head-up displays.

[0066] Finally, it should be noted that the above descriptions are merely embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An optical module, comprising: The image generation unit is configured to emit image light carrying image information; A reflective component is configured to receive image light emitted by the image generation unit and reflect it to the outside of the optical module; A light-blocking component is disposed between the light-emitting side of the image generating unit and the reflective component, and configured to allow the image light to pass through and at least partially block light from outside the optical module from entering the image generating unit. The light-blocking component includes multiple structural layers stacked along the direction of the image light, wherein the refractive index of at least two adjacent structural layers increases along the direction of the image light. The multiple structural layers include a microstructure film layer, wherein the microstructure film layer is closest to the image generating unit, and the side of the microstructure film layer facing the image generating unit is configured with a sawtooth structure.

2. The optical module according to claim 1, wherein, The serrated structure includes one or more teeth, each tooth having a vertical surface and an inclined surface.

3. The optical module according to claim 1, wherein, The plurality of structural layers further include a glass substrate layer, a polarization selection layer and / or a bandpass filter layer; the bandpass region of the bandpass filter layer is the visible light band; the image light is S-polarized light, and the polarization selection layer is configured to transmit S-polarized light and filter P-polarized light, or the image light is P-polarized light, and the polarization selection layer is configured to transmit P-polarized light and filter S-polarized light.

4. The optical module according to claim 3, wherein, The refractive index of the structural layer located upstream of and adjacent to the glass substrate layer is less than that of the glass substrate layer.

5. The optical module according to claim 4, wherein, The microstructure film layer is adjacent to the glass substrate layer, and the polarization selection layer and / or the bandpass filter layer are disposed on the side of the glass substrate layer facing away from the microstructure film layer.

6. The optical module according to claim 4, wherein, The polarization selection layer and / or bandpass filter layer are disposed between the microstructure film layer and the glass substrate layer.

7. The optical module according to claim 4, wherein, The polarization selection layer and the bandpass filter layer are respectively disposed on both sides of the glass substrate layer.

8. The optical module according to any one of claims 1-7, wherein, The angle between the light-emitting surface of the light-blocking component and the light-emitting surface of the image generation unit is 10-50°.

9. The optical module according to any one of claims 1-7, wherein, The refractive index of the multiple structural layers increases sequentially along the direction of the image light.

10. The optical module according to any one of claims 1-7, wherein, The projected area of ​​the light-emitting surface of the light-blocking component on the image generating unit is larger than the area of ​​the light-emitting surface of the image generating unit.

11. The optical module according to any one of claims 1-7, wherein, The reflective component includes a first reflector and a second reflector. The first reflector is configured to receive the image light transmitted by the light-blocking component and reflect the image light toward the second reflector. The second reflector is configured to receive the image light reflected from the first reflector and reflect the image light toward a preset direction.

12. The optical module according to claim 11, wherein, The first reflecting mirror is a curved mirror or a plane mirror; the second reflecting mirror is a curved mirror.

13. A head-up display comprising the optical module according to any one of claims 1-12.

Images