Virtual image display system, electronic equipment and vehicle

Abstract

The embodiment of the utility model provides a virtual image display system, electronic equipment and a vehicle, and relates to the technical field of display. The virtual image display system comprises a display, a transflective mirror and a spectroscope. The light-emitting surface of the display is used for emitting first circularly polarized light and faces the transflective mirror. The transflective mirror is provided with an incident surface and an emergent surface which are opposite to each other, and the incident surface faces the display. The transflective mirror is used for converting the first circularly polarized light incident from the incident plane into second circularly polarized light and emitting the second circularly polarized light through the incident plane. And the transflective mirror is also used for converting the second circularly polarized light incident from the incident surface into first linearly polarized light and emitting the first linearly polarized light through the emergent surface. The spectroscope is located between the display and the transflective mirror and is used for transmitting part of the first circularly polarized light emitted by the light-emitting surface, so that the first circularly polarized light is irradiated to the incident surface. The spectroscope is also used for reflecting a part of the second circularly polarized light emitted by the incident plane, so that the second circularly polarized light irradiates the incident plane. The included angle between the central normal of the spectroscope and the incident plane is larger than 45 degrees and smaller than 90 degrees.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of display technology, and in particular to a virtual image display system, electronic equipment and a vehicle. Background Art

[0002] The virtual image display system can project the virtual image of an object in front of the user's field of vision, so as to facilitate the user to see the object. For example, the head up display (HUD) system can project the vehicle's instrument information and navigation information in front of the driver's field of vision, so that the driver does not need to look down at the instrument panel or central control display under the steering wheel, but can see the instrument information and navigation information in front of the field of vision.

[0003] In the related art, a virtual image display system includes a display screen, a semi-transparent mirror, and a reflective polarizer arranged in sequence. The light emitted by the display screen can be folded between the semi-transparent mirror and the reflective polarizer, thereby shortening the optical path distance, thereby achieving the purpose of reducing the volume of the virtual image display system. However, the virtual image projected by the virtual image display system has ghost images and poor imaging quality. Utility Model Content

[0004] The embodiments of the present application provide a virtual image display system, an electronic device, and a vehicle, which can improve the problem of ghost images in the virtual images projected by the virtual image display system, thereby improving the imaging quality.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect of the present application, a virtual image display system is provided, which includes a display, a transflective mirror and a beam splitter. The display has a light emitting surface, which is used to emit a first circularly polarized light. The transflective mirror is located on one side of the display, and the light emitting surface faces the transflective mirror. The transflective mirror has an incident surface and an exit surface opposite to each other, and the incident surface faces the display. The transflective mirror is used to convert the first circularly polarized light incident on the incident surface into a second circularly polarized light, and emit it through the incident surface. The transflective mirror is also used to convert the second circularly polarized light incident on the incident surface into a first linearly polarized light, and emit it through the exit surface. The beam splitter is located between the display and the transflective mirror. The beam splitter is used to transmit part of the first circularly polarized light emitted from the light exit surface, so that the first circularly polarized light is irradiated onto the incident surface. The beam splitter is also used to reflect part of the second circularly polarized light emitted from the incident surface, so that the second circularly polarized light is irradiated onto the incident surface.

[0007] In this way, part of the light emitted from the light emitting surface of the display can pass through the beam splitter to irradiate the transflective mirror, and be reflected by the transflective mirror to the beam splitter. Part of the light reflected on the beam splitter will be reflected by the beam splitter to the transflective mirror, and then emitted through the transflective mirror to form a virtual image, thus realizing screen display.

[0008] However, due to the limitation of the performance of the reflector itself, it is difficult for all the light reflected by the beam splitter to the reflector to pass through the reflector. Among them, the part of the light that has not passed through the reflector will be reflected again by the reflector to the beam splitter, and part of the light will be reflected again by the beam splitter to the reflector, and then emitted through the reflector to form ghost image 1. In the process of forming ghost image 1, there is still part of the light that cannot pass through the reflector, and this part of the light will be reflected again by the reflector to the beam splitter, and part of the light will be reflected again by the beam splitter to the reflector, and then emitted through the reflector to form ghost image 2. Among them, ghost image 1 and ghost image 2 will have an adverse effect on the virtual image projected by the virtual image display system, resulting in poor imaging quality.

[0009] In the embodiment of the present application, the beam splitter has a central normal, the central normal is perpendicular to the surface of the beam splitter for reflecting the second circularly polarized light, and the geometric center of the surface of the beam splitter for reflecting the second circularly polarized light is located on the central normal. The angle between the incident surface and the central normal is greater than 45° and less than 90°. In this way, after the light emitted by the display is reflected by the transflector, the light path forming ghost image 1 and ghost image 2 will be separated from the light path forming the virtual image, so that ghost image 1 and ghost image 2 are separated from the virtual image, thereby reducing the adverse effects of ghost image 1 and ghost image 2 on the virtual image and improving the imaging quality.

[0010] In an optional implementation, the angle between the incident plane and the center normal is greater than or equal to 50°, and less than or equal to 85°. On the one hand, when the angle between the incident plane and the center normal is less than 50°, the virtual image deviates from the center normal of the beam splitter by a large distance, and the virtual image will be deformed to a large extent, resulting in poor imaging quality. On the other hand, when the angle between the incident plane and the center normal is greater than 85°, the ghost image deviates from the virtual image by a large distance, and some ghost images cannot be separated from the virtual image well, resulting in poor imaging quality. Based on this, setting the angle between the incident plane and the center normal to be greater than or equal to 50°, and less than or equal to 85°, can improve imaging quality.

[0011] In an optional implementation, the two ends of the incident surface in the first direction are respectively a first end and a second end, and the first end is inclined relative to the second end toward a direction close to the beam splitter. The first direction is perpendicular to the central normal line, and the first direction is parallel to the reference plane; the central normal line is located in the reference plane, and the incident surface is perpendicular to the reference plane.

[0012] In an optional implementation, the center of the light emitting surface is located in the reference plane, and the light emitting surface is perpendicular to the reference plane. The two ends of the light emitting surface in the first direction are the third end and the fourth end, respectively, and the third end and the first end are located on the same side of the reference line. Among them, the center of the light emitting surface is located on the reference line, and the intersection of the center normal and the incident surface is located on the reference line. On this basis, the third end is inclined relative to the fourth end in a direction away from the beam splitter, that is, the light emitting surface and the incident surface are inclined in the same direction relative to the center normal. In this way, the virtual image formed by the virtual image display system can be closer to being perpendicular to the center normal. In this way, it is helpful to reduce the degree of deformation of the virtual image, thereby obtaining higher imaging quality.

[0013] In an optional implementation, the angle between the light emitting surface and the first direction is less than or equal to twice the angle between the incident surface and the first direction.

[0014] In an optional implementation, the center of the light emitting surface is located on the side of the center normal line close to the second end, and the angle between the center normal line and the reference line is less than or equal to twice the angle between the incident surface and the first direction. In this way, the distance between the center of the virtual image formed by the virtual image display system and the center normal line can be reduced. In this way, it is helpful to reduce the degree of deformation of the virtual image, thereby facilitating obtaining higher imaging quality.

[0015] In an optional implementation, the display includes a display module and a first quarter wave plate. The display module is used to emit a first polarized light. The first quarter wave plate is located between the display module and the beam splitter, and the first quarter wave plate is used to convert the first polarized light emitted by the display module into a first circularly polarized light. The surface of the first quarter wave plate facing away from the display module is a light emitting surface.

[0016] In an optional implementation, the transflector includes a second 1 / 4 wave plate and a polarized reflective film. The surface of the second 1 / 4 wave plate close to the beam splitter is the incident surface. The second 1 / 4 wave plate is used to convert the first circularly polarized light into the second linearly polarized light, and to convert the second linearly polarized light into the second circularly polarized light, and to convert the second circularly polarized light into the first linearly polarized light. The second 1 / 4 wave plate is located between the polarized reflective film and the beam splitter. The polarized reflective film is used to transmit the first linearly polarized light, and to reflect the second linearly polarized light. In this way, after passing through the beam splitter, part of the first circularly polarized light emitted by the display will enter the second 1 / 4 wave plate and be converted into the second linearly polarized light, and then irradiate the polarized reflective film. The second linearly polarized light irradiated on the polarized reflective film will be reflected back to the second 1 / 4 wave plate by the polarized reflective film, and will be converted into the second circularly polarized light, and then transmitted to the beam splitter. Part of the second circularly polarized light transmitted to the beam splitter will be reflected back to the second 1 / 4 wave plate by the beam splitter, and will be converted into the first linearly polarized light, and then emitted through the polarized reflective film.

[0017] In an optional implementation, the transflective mirror further includes a substrate layer, the polarizing reflective film is located between the second 1 / 4 wave plate and the substrate layer, and the polarizing reflective film is connected to the second 1 / 4 wave plate and the substrate layer. The substrate layer can provide support and protection for the polarizing reflective film.

[0018] In an optional implementation, the beam splitter is a curved mirror and is concave toward the direction close to the display. The curved mirror can increase the size of the virtual image projected by the virtual image display system to obtain an enlarged virtual image.

[0019] In an optional implementation, the beam splitter is a free-form surface mirror, which is beneficial to improving imaging quality.

[0020] In an optional implementation, the beam splitter includes a light-transmitting mirror and a beam splitter film, and the beam splitter film is attached to the light-transmitting mirror. The beam splitter film is used to transmit part of the first circularly polarized light emitted from the light-emitting surface and to reflect part of the second circularly polarized light emitted from the incident surface.

[0021] In an optional implementation, the splitting ratio of the splitter film is 5:5.

[0022] The second aspect of the present application provides an electronic device, which includes the virtual image display system in the first aspect. The electronic device has the same technical effect as the virtual image display system provided in any embodiment of the first aspect, and will not be described in detail here.

[0023] The third aspect of the present application provides a vehicle, which includes the virtual image display system in the first aspect. The vehicle has the same technical effects as the virtual image display system provided in any embodiment of the first aspect, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the principle of a virtual image display system provided for related technologies;

[0025] Figure 2 A schematic diagram of an optical path for forming a virtual image in a virtual image display system provided in the related art;

[0026] Figure 3 A schematic diagram of the optical path of a virtual image display system forming a ghost image is provided for the related technology;

[0027] Figure 4 A schematic diagram of the optical path of a virtual image display system forming a second ghost image is provided for the related technology;

[0028] Figure 5 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0029] Figure 6A schematic diagram of the structure of a display provided in an embodiment of the present application;

[0030] Figure 7 A schematic diagram of the structure of a display provided in an embodiment of the present application;

[0031] Figure 8 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0032] Fig. 9 A schematic diagram of the structure of a spectroscope provided in an embodiment of the present application;

[0033] Fig.10 A schematic diagram of a light path for forming a virtual image in a virtual image display system provided in an embodiment of the present application;

[0034] Fig.11 A schematic diagram of a light path for forming a virtual image in a virtual image display system provided in an embodiment of the present application;

[0035] Fig.12 A schematic diagram of an optical path for forming a ghost image in a virtual image display system provided in an embodiment of the present application;

[0036] Fig.13 A schematic diagram of a light path for forming a second ghost image in a virtual image display system provided in an embodiment of the present application;

[0037] Fig.14 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0038] Fig.15 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0039] Fig.16 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0040] Fig.17 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0041] Fig.18 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0042] Fig.19 A schematic diagram of the structure of a virtual image display system provided in an embodiment of the present application;

[0043] Fig. 20 A schematic structural diagram of a transflective mirror provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0045] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "plurality" means two or more.

[0046] In addition, in the present application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they may change accordingly according to the changes in the orientation of the components in the drawings.

[0047] Virtual image display system is a display technology that uses optical principles to generate virtual images in the air. It is usually used in flight simulators, car driving simulations, virtual reality (VR) experience and augmented reality (AR) applications. Figure 1 As shown, Figure 1 A schematic diagram of the principle of a virtual image display system 01 provided for related technologies. This display technology does not rely on a physical screen, but uses a series of complex optical components (such as curved mirrors) to guide the light emitted by the image display unit and construct an image that seems to be suspended in space, which is a virtual image. The virtual image display system 01 can use the optical virtual image display magnification characteristics to obtain a larger display frame with a smaller volume. At the same time, since the imaging distance is often far, it can provide users with a more comfortable viewing experience.

[0048] At present, the pancake architecture is a widely used technology route in the field of virtual image magnification display technology. It mainly uses polarization optics to fold the imaging light path to achieve the purpose of reducing the volume of the virtual image display system.

[0049] In the related art, see Figure 2 , Figure 2A virtual image display system 01 provided for related technology forms a schematic diagram of the optical path of a virtual image. The virtual image display system 01 adopts a pancake architecture, and the virtual image display system 01 includes a display unit 011, a first 1 / 4 wave plate 012, a semi-transparent and semi-reflective mirror 013, a second 1 / 4 wave plate 014 and a polarized reflective film 015 arranged in sequence. Among them, the display unit 011 is used to emit linear polarized light, and the linear polarized light is converted into a first circularly polarized light through the first 1 / 4 wave plate 012, and part of the first circularly polarized light passes through the semi-transparent and semi-reflective mirror 013 and is converted into S polarized light through the second 1 / 4 wave plate 014. After the S polarized light is irradiated onto the polarized reflective film 015, it is reflected by the polarized reflective film 015 onto the second 1 / 4 wave plate 014, and then converted into a second circularly polarized light through the second 1 / 4 wave plate 014. Among them, part of the second circularly polarized light will be reflected by the semi-transparent and semi-reflective mirror 013 onto the second 1 / 4 wave plate 014, and then converted into P polarized light through the second 1 / 4 wave plate 014. The P polarized light can pass through the polarizing reflective film 015 to form a virtual image to realize picture display.

[0050] However, if Figure 3 As shown, Figure 3 A schematic diagram of the optical path of a virtual image display system 01 provided for related technology to form a ghost image. Affected by the performance of the polarizing reflective film 015 itself, the above-mentioned P polarized light cannot completely pass through the polarizing reflective film 015, and part of the P polarized light will be reflected by the polarizing reflective film 015 to the second 1 / 4 wave plate 014, and then converted into the first circular polarized light through the second 1 / 4 wave plate 014, and irradiated onto the semi-transparent and semi-reflective mirror 013. Among them, part of the first circular polarized light will be reflected by the semi-transparent and semi-reflective mirror to the second 1 / 4 wave plate 014, and then converted into S polarized light through the second 1 / 4 wave plate 014. Part of the S polarized light will pass through the polarizing reflective film 015, thereby forming an inverted ghost image on the side of the polarizing reflective film 015 away from the semi-transparent and semi-reflective mirror 013.

[0051] like Figure 4 As shown, Figure 4 A schematic diagram of the optical path of a virtual image display system 01 that forms a second ghost image is provided for the related art. Another part of the S polarized light will be reflected by the polarizing reflective film 015 onto the second 1 / 4 wave plate 014, and then converted into a second circularly polarized light by the second 1 / 4 wave plate 014, and irradiated onto the semi-transparent and semi-reflective mirror 013. Among them, part of the second circularly polarized light will be reflected by the semi-transparent and semi-reflective mirror 013 onto the second 1 / 4 wave plate 014, and then converted into a P polarized light by the second 1 / 4 wave plate 014. This part of the P polarized light can pass through the polarizing reflective film 015, and then form another inverted ghost image 2 between the semi-transparent and semi-reflective mirror 013 and the second 1 / 4 wave plate 014. Ghost image 1 and ghost image 2 will have an adverse effect on the virtual image projected by the virtual image display system 01, resulting in poor imaging quality.

[0052] Based on this, see Figure 5 , Figure 5 The structure diagram of a virtual image display system 100 provided in an embodiment of the present application is shown in FIG. The virtual image display system 100 provided in an embodiment of the present application is used to reduce the adverse effects of ghost image 1 and ghost image 2 on the virtual image projected by the virtual image display system, thereby improving the imaging quality.

[0053] The virtual image display system 100 includes a display 1, which may be a liquid crystal display (LCD), a light emitting diode (LED), an organic light emitting diode (OLED), or a combination thereof.

[0054] The following takes the display 1 being an LCD as an example to exemplarily illustrate some embodiments of the present application.

[0055] The display 1 has a light emitting surface 11, and the light emitting surface 11 is used for emitting the first circularly polarized light.

[0056] Among them, see Figure 6 , Figure 6 A schematic diagram of the structure of a display 1 provided in an embodiment of the present application. The display 1 may include a display module 12 and a first quarter wave plate 13, wherein the display module 12 is used to emit a first polarized light, and the first quarter wave plate 13 may convert the first polarized light emitted by the display module 12 into a first circularly polarized light.

[0057] For example, Figure 6 As shown, the display module 12 has a display surface 121 and a back surface 122 facing each other, and the first quarter wave plate 13 is disposed on the side of the display surface 121 away from the back surface 122, and the first quarter wave plate 13 is attached to the display surface 121. At this time, the surface of the first quarter wave plate 13 away from the display module 12 is the light exit surface 11. In this way, the first polarized light emitted by the display module 12 can be incident into the first quarter wave plate 13, and is converted into the first circularly polarized light through the first quarter wave plate 13, and then emitted through the light exit surface 11.

[0058] like Figure 7 As shown, Figure 7A schematic diagram of the structure of a display 1 provided in an embodiment of the present application. The display module 12 may include a display screen 123 and a polarizer 124, and the display screen 123 is used to emit non-polarized light. The polarizer 124 is located between the display screen 123 and the first 1 / 4 wave plate 13, and the polarizer 124 is used to convert the non-polarized light emitted by the display screen 123 into a first polarized light. In this case, the non-polarized light emitted by the display screen 123 can be converted into the first polarized light through the polarizer 124, and then converted into the first circularly polarized light through the first 1 / 4 wave plate 13, and then emitted through the light emitting surface 11.

[0059] It is understandable that the polarizing plate 124 can be configured to fit the display screen 123 and the first quarter wave plate 13 .

[0060] In some embodiments, see Figure 5 The virtual image display system 100 further includes a beam splitter 2, which is disposed on one side of the display 1 and is used to transmit part of the first circularly polarized light emitted from the light emitting surface 11 of the display 1. That is, after the first circularly polarized light emitted from the display 1 is irradiated onto the beam splitter 2, part of the first circularly polarized light can pass through the beam splitter 2.

[0061] For example, Figure 8 As shown, Figure 8 A schematic diagram of the structure of a virtual image display system 100 provided in an embodiment of the present application. The light-emitting surface 11 of the display 1 faces the beam splitter 2. For example, when the display 1 includes a first 1 / 4 wave plate 13 and a display module 12, the first 1 / 4 wave plate 13 is located between the display module 12 and the beam splitter 2. In this way, it is convenient to make the first circularly polarized light emitted by the display 1 irradiate the beam splitter 2, and then make part of the first circularly polarized light pass through the beam splitter 2.

[0062] In some embodiments, Figure 8 As shown, the beam splitter 2 is a curved mirror, and is concave toward the direction close to the display 1. The curved mirror can increase the size of the virtual image projected by the virtual image display system 100, thereby obtaining an enlarged virtual image. In this way, it is convenient for users to watch and is conducive to improving the user experience.

[0063] On this basis, the beam splitter 2 can be a free-form surface mirror. It can be understood that the free-form surface mirror can effectively correct phase difference, which is beneficial to improving imaging quality.

[0064] It is understandable that the beam splitter 2 may also be a plane mirror, which may be selected according to actual conditions, and the present application does not make any specific limitation thereto.

[0065] In some embodiments, see Fig. 9 , Fig. 9The schematic diagram of the structure of a beam splitter 2 provided in an embodiment of the present application is as follows. The beam splitter 2 comprises a light-transmitting mirror 22 and a beam splitting film 23 , and the beam splitting film 23 is bonded to the light-transmitting mirror 22 .

[0066] The light splitting film 23 can be arranged on the light transmitting mirror 22 and the display 1 (such as Figure 8 As shown), it can also be set on the side of the light-transmitting mirror 22 away from the display 1. The specific selection can be made according to actual conditions, and this application does not make any specific limitation on this.

[0067] In the following, some embodiments of the present application are exemplarily described by taking the case where the light-splitting film 23 is disposed on the side of the light-transmitting mirror 22 facing away from the display 1 as an example.

[0068] The first circularly polarized light emitted by the display 1 can be irradiated onto the light-transmitting mirror 22, and then irradiated onto the dichroic film 23 through the light-transmitting mirror 22, and the dichroic film 23 can transmit part of the first circularly polarized light. For example, part of the first circularly polarized light irradiated onto the dichroic film 23 is transmitted through the dichroic film 23, and the other part is reflected by the dichroic film 23.

[0069] The splitting ratio of the splitter film 23 may be any one of 2:8, 3:7, 4:6 and 5:5, or the splitting ratio of the splitter film 23 may be other ratios, which may be selected according to actual conditions, and the present application does not make any specific limitation on this.

[0070] Exemplarily, the splitting ratio of the prismatic film 23 is 5:5, that is, the transmittance and reflectance of the prismatic film 23 are both 50%. At this time, the prismatic film 23 can be regarded as a semi-transmissive and semi-reflective film.

[0071] In some embodiments, see Figure 5 The virtual image display system 100 further includes a transflective mirror 3, which is located at one side of the display 1, and the light emitting surface 11 faces the transflective mirror 3. The transflective mirror 3 has an incident surface 31 and an emitting surface 32 which are opposite to each other, and the incident surface 31 faces the display 1.

[0072] The reflective mirror 3 can convert the first circularly polarized light incident on the incident surface 31 into the second circularly polarized light, and emit it through the incident surface 31. The reflective mirror 3 can also convert the second circularly polarized light incident on the incident surface 31 into the first linearly polarized light, and emit it through the exit surface 32. In other words, the first circularly polarized light irradiated on the incident surface 31 will be converted into the second circularly polarized light by the reflective mirror 3, and then reflected by the reflective mirror 3; the second circularly polarized light irradiated on the incident surface 31 will be converted into the first linearly polarized light by the reflective mirror 3, and then pass through the reflective mirror 3 and emit it from the exit surface 32.

[0073] like Figure 5As shown, the beam splitter 2 is located between the display 1 and the transflector 3. On the one hand, the beam splitter 2 is used to transmit part of the first circularly polarized light emitted from the light output surface 11, so that the first circularly polarized light is irradiated onto the incident surface 31. On the other hand, the beam splitter 2 is used to reflect part of the second circularly polarized light emitted from the incident surface 31, so that the second circularly polarized light is irradiated onto the incident surface 31.

[0074] In this way, if Fig.10 As shown, Fig.10 A schematic diagram of the optical path of a virtual image formed by a virtual image display system 100 provided in an embodiment of the present application. Part of the first circularly polarized light emitted from the light exiting surface 11 of the display 1 can pass through the beam splitter 2 and irradiate onto the incident surface 31 of the transflector 3, and then be converted into the second circularly polarized light by the transflector 3, and be reflected by the transflector 3 and emitted from the incident surface 31. Afterwards, the second circularly polarized light emitted from the incident surface 31 will irradiate the beam splitter 2, and part of the second circularly polarized light will be re-reflected by the beam splitter 2 onto the incident surface 31, and then be converted into the first linear polarized light by the transflector 3, and pass through the transflector 3 and be emitted from the exit surface 32. Among them, the first linear polarized light emitted from the exit surface 32 can form a virtual image, so that the virtual image display system 100 can realize screen display.

[0075] For example, Figure 8 As shown, the transflector 3 includes a second 1 / 4 wave plate 33 and a polarizing reflective film 34, and the second 1 / 4 wave plate 33 is located between the polarizing reflective film 34 and the beam splitter 2. In this case, the surface of the second 1 / 4 wave plate 33 close to the beam splitter 2 is the incident surface 31.

[0076] Among them, the second 1 / 4 wave plate 33 can convert the first circularly polarized light into the second linearly polarized light, that is, the first circularly polarized light irradiated on the second 1 / 4 wave plate 33 will be converted into the second linearly polarized light by the second 1 / 4 wave plate 33, and pass through the second 1 / 4 wave plate 33. The second 1 / 4 wave plate 33 can also convert the second linearly polarized light into the second circularly polarized light, that is, the second linearly polarized light irradiated on the second 1 / 4 wave plate 33 will be converted into the second circularly polarized light by the second 1 / 4 wave plate 33, and pass through the second 1 / 4 wave plate 33. The second 1 / 4 wave plate 33 can also convert the second circularly polarized light into the first linearly polarized light, that is, the second circularly polarized light irradiated on the second 1 / 4 wave plate 33 will be converted into the first linearly polarized light by the second 1 / 4 wave plate 33, and pass through the second 1 / 4 wave plate 33.

[0077] In addition, the polarizing reflective film 34 can transmit the first linear polarized light and reflect the second linear polarized light. That is, the first linear polarized light irradiated on the polarizing reflective film 34 can pass through the polarizing reflective film 34, while the second linear polarized light irradiated on the polarizing reflective film 34 is reflected by the polarizing reflective film 34.

[0078] In this way, if Fig.11 As shown, Fig.11 A schematic diagram of the optical path of a virtual image formed by a virtual image display system 100 provided in an embodiment of the present application. Part of the first circularly polarized light emitted from the light exiting surface 11 of the display 1 can be irradiated onto the incident surface 31 of the second 1 / 4 wave plate 33 through the beam splitter 2, and then converted into the second linear polarized light by the second 1 / 4 wave plate 33, and irradiated onto the polarizing reflective film 34 through the second 1 / 4 wave plate 33. Afterwards, the second linear polarized light irradiated onto the polarizing reflective film 34 is reflected back to the second 1 / 4 wave plate 33 by the polarizing reflective film 34, and then converted into the second circular polarized light by the second 1 / 4 wave plate 33, and irradiated onto the beam splitter 2 through the second 1 / 4 wave plate 33. Part of the second circularly polarized light irradiated onto the beam splitter 2 is reflected by the beam splitter 2 onto the incident surface 31 of the second 1 / 4 wave plate 33, and then converted into the first linear polarized light by the second 1 / 4 wave plate 33, and irradiated onto the polarizing reflective film 34 through the second 1 / 4 wave plate 33. The first linear polarized light irradiated onto the polarizing reflective film 34 can pass through the polarizing reflective film 34 to form a virtual image, so that the virtual image display system 100 can realize picture display.

[0079] like Fig.12 As shown, Fig.12 FIG. 1 is a schematic diagram of the optical path of a virtual image display system 100 provided in an embodiment of the present application to form a ghost image. Due to the limitation of the performance of the reflective mirror 3, part of the light emitted by the display 1 can pass through Fig.12 The light path shown forms a ghost image 1. For details, please refer to the description of the ghost image 1 formation process in the above text, which will not be repeated here.

[0080] In addition, if Fig.13 As shown, Fig.13 Schematic diagram of the light path of a virtual image display system 100 provided in an embodiment of the present application to form a second ghost image. Due to the limitation of the performance of the reflective mirror 3 itself, part of the light emitted by the display 1 can pass through Fig.13 The light path shown forms ghost image 2. For details, please refer to the description of the process of ghost image 2 formation in the above text, which will not be repeated here.

[0081] In some embodiments of the present application, see Figure 8 , the beam splitter 2 has a central normal line 21, wherein the central normal line 21 is perpendicular to the surface of the beam splitter 2 for reflecting the second circularly polarized light, and the geometric center of the surface of the beam splitter 2 for reflecting the second circularly polarized light is located on the central normal line 21. For example, in the case where the beam splitter 2 includes a light-transmitting mirror 22 and a beam splitter film 23, the central normal line 21 is perpendicular to the beam splitter film 23, and the geometric center of the beam splitter film 23 is located on the central normal line 21.

[0082] It should be noted that, when the beam splitter 2 is a curved mirror, the surface of the beam splitter 2 used to reflect the second circularly polarized light is a curved surface. At this time, the central normal 21 is perpendicular to the surface of the beam splitter 2 used to reflect the second circularly polarized light, which means that the central normal 21 is perpendicular to the tangent plane at the intersection of the curved surface and the central normal 21.

[0083] On this basis, see Fig.14 , Fig.14 The schematic diagram of the structure of a virtual image display system 100 provided in an embodiment of the present application. The angle θ between the incident surface 31 of the reflector 3 and the central normal 21 of the beam splitter 2 is greater than 45° and less than 90°. In this way, after the light emitted by the display 1 is reflected by the reflector 3, the light path forming the ghost image 1 and the ghost image 2 will be separated from the light path forming the virtual image, so that the ghost image 1 and the ghost image 2 are separated from the virtual image. In this way, the adverse effects of the ghost image 1 and the ghost image 2 on the virtual image can be reduced, and the imaging quality can be improved.

[0084] In some other embodiments of the present application, the angle θ between the incident surface 31 of the reflector 3 and the center normal 21 of the beam splitter 2 is greater than or equal to 50° and less than or equal to 85°. On the one hand, when the angle θ between the incident surface 31 and the center normal 21 is less than 50°, the virtual image deviates from the center normal 21 of the beam splitter 2 by a large distance, and the virtual image will be deformed to a large extent, resulting in poor imaging quality. On the other hand, when the angle θ between the incident surface 31 and the center normal 21 is greater than 85°, the ghost image deviates from the virtual image by a small distance, and some ghost images cannot be separated from the virtual image well, resulting in poor imaging quality. Based on this, setting the angle θ between the incident surface 31 and the center normal 21 to be greater than or equal to 50° and less than or equal to 85° can improve the imaging quality.

[0085] It is understandable that the smaller the divergence angle of the display 1 is, the larger the angle θ between the incident surface 31 and the central normal 21 needs to be set, that is, the smaller the inclination angle of the incident surface 31 relative to the beam splitter 2 can be set. In this way, the ghost image can be completely separated from the virtual image, thereby improving the imaging quality.

[0086] In some embodiments, Fig.14 As shown, the incident surface 31 is perpendicular to the reference surface S, and the light emitting surface 11 is perpendicular to the reference surface S. The center and the center normal 21 of the light emitting surface 11 are located in the reference surface S, that is, the reference surface S is the plane where the center and the center normal 21 of the light emitting surface 11 are located.

[0087] In this way, the center of the virtual image projected by the virtual image display system 100 can be kept within the reference plane S where the center normal line 21 is located. This is helpful to reduce the degree of deformation of the virtual image, thereby obtaining higher imaging quality.

[0088] For example, Fig.15 As shown, Fig.15 A schematic diagram of the structure of a virtual image display system 100 provided in an embodiment of the present application. The two ends of the incident surface 31 in the first direction are respectively the first end 311 and the second end 312, and the two ends of the light emitting surface 11 in the first direction are respectively the third end 111 and the fourth end 112. The first direction is perpendicular to the center normal 21, and the first direction is parallel to the reference plane S. In addition, the third end 111 and the first end 311 are located on the same side of the reference line L, wherein the center of the light emitting surface 11 is located on the reference line L, and the intersection of the center normal 21 and the incident surface 31 is located on the reference line L.

[0089] On this basis, the first end 311 is inclined relative to the second end 312 toward the direction close to the beam splitter 2, and the third end 111 is inclined relative to the fourth end 112 toward the direction away from the beam splitter 2. In other words, the light emitting surface 11 and the incident surface 31 are inclined relative to the center normal 21 in the same direction.

[0090] The angle α between the light emitting surface 11 and the first direction is less than or equal to twice the angle β between the incident surface 31 and the first direction. In this way, the virtual image formed by the virtual image display system 100 can be closer to being perpendicular to the central normal line 21. In this way, it is helpful to reduce the degree of deformation of the virtual image, thereby obtaining a higher imaging quality.

[0091] For example, Fig.16 As shown, Fig.16 A schematic diagram of the structure of a virtual image display system 100 provided in an embodiment of the present application. The angle α between the light emitting surface 11 and the first direction is equal to twice the angle β between the incident surface 31 and the first direction. In this case, the virtual image formed by the virtual image display system 100 is perpendicular to the central normal 21, so that higher imaging quality can be obtained.

[0092] In some embodiments, see Fig.17 , Fig.17 A schematic diagram of the structure of a virtual image display system 100 provided in an embodiment of the present application. The center of the light emitting surface 11 is located on the side of the center normal 21 close to the second end 312, and the angle γ between the center normal 21 and the reference line L is less than or equal to twice the angle β between the incident surface 31 and the first direction. For example, the angle γ between the center normal 21 and the reference line L is equal to the angle β between the incident surface 31 and the first direction, and for another example, the angle γ between the center normal 21 and the reference line L is equal to twice the angle β between the incident surface 31 and the first direction.

[0093] By setting in this way, the distance between the center of the virtual image formed by the virtual image display system 100 and the center normal 21 can be reduced, so that the position of the eye box is close to the center normal 21 and close to being perpendicular to the center normal 21. The position of the eye box refers to the area where the user's pupil can receive a focused and clear image. In this way, it is helpful to reduce the degree of deformation of the virtual image, thereby obtaining a higher imaging quality.

[0094] For example, Fig.18 As shown, Fig.18 A schematic diagram of the structure of a virtual image display system 100 provided in an embodiment of the present application. The angle γ between the center normal line 21 and the reference line L is equal to twice the angle β between the incident surface 31 and the first direction. In this case, the center of the virtual image formed by the virtual image display system is located on the center normal line 21, so that higher imaging quality can be obtained.

[0095] In other embodiments, see Fig.19 , Fig.19 A schematic diagram of the structure of a virtual image display system 100 provided in an embodiment of the present application. The center of the light emitting surface 11 is located on the side of the center normal 21 close to the second end 312, the angle α between the light emitting surface 11 and the first direction is equal to twice the angle β between the incident surface 31 and the first direction, and the angle γ between the center normal 21 and the reference line L is equal to twice the angle β between the incident surface 31 and the first direction. In this case, the virtual image formed by the virtual image display system 100 is perpendicular to the center normal 21, and the center of the virtual image is located on the center normal 21. In this way, higher imaging quality can be obtained.

[0096] In this case, the distance H between the center of the light emitting surface 11 and the center normal 21 satisfies: H=X*sinγ=X*sin2β=X*sin2α; wherein X is the distance between the intersection of the center normal 21 and the incident surface 31 and the center of the light emitting surface 11, γ is the angle between the center normal 21 and the reference line L, β is the angle between the incident surface 31 and the first direction, and α is the angle between the light emitting surface 11 and the first direction.

[0097] In some embodiments, see Fig. 20 , Fig. 20 The schematic diagram of the structure of a transflective mirror 3 provided in an embodiment of the present application. The transflective mirror 3 further includes a substrate layer 35, a polarizing reflective film 34 is located between the second quarter wave plate 33 and the substrate layer 35, and the polarizing reflective film 34 is connected to the second quarter wave plate 33 and the substrate layer 35. The substrate layer 35 can be made of transparent materials such as glass and acrylic, and the substrate layer 35 can provide support and protection for the polarizing reflective film 34.

[0098] For example, Fig. 20As shown, the polarizing reflective film 34 is attached to the substrate layer 35. For example, the polarizing reflective film 34 is bonded to the surface of the substrate layer 35 by optical adhesive. In this way, the substrate layer 35 can provide better support for the polarizing reflective film 34, reduce the risk of wrinkles on the polarizing reflective film 34, and help improve the optical performance of the transflective mirror 3.

[0099] In addition, the polarizing reflective film 34 may also be attached to the second quarter wave plate 33. For example, the polarizing reflective film 34 is bonded to the surface of the second quarter wave plate 33 by optical adhesive.

[0100] Some embodiments of the present application also provide an electronic device, which may be a head mounted display (HMD), a head up display (HUD), a flight simulator (CNFS), a tablet computer, a television, a projector and other devices.

[0101] The electronic device includes the virtual image display system 100 in any of the above embodiments. The electronic device has the same technical effects as the virtual image display system 100 provided in any of the above embodiments, which will not be described in detail here.

[0102] Some embodiments of the present application further provide a vehicle, which includes the virtual image display system 100 in any of the above embodiments. The vehicle has the same technical effects as the virtual image display system 100 provided in any of the above embodiments, which will not be described in detail here.

[0103] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A virtual image display system, characterized in that: include: A display, wherein the display has a light emitting surface, and the light emitting surface is used to emit a first circularly polarized light; a transflective mirror, the transflective mirror being located at one side of the display, and the light emitting surface facing the transflective mirror; the transflective mirror having an incident surface and an exiting surface facing each other, the incident surface facing the display; the transflective mirror being used to convert the first circularly polarized light incident on the incident surface into a second circularly polarized light, and emit the light through the incident surface; and the transflective mirror being used to convert the second circularly polarized light incident on the incident surface into a first linearly polarized light, and emit the light through the exiting surface; a beam splitter, the beam splitter being located between the display and the transflective mirror; the beam splitter being used to transmit a portion of the first circularly polarized light emitted from the light emitting surface so that the first circularly polarized light is irradiated onto the incident surface; and the beam splitter being used to reflect a portion of the second circularly polarized light emitted from the incident surface so that the second circularly polarized light is irradiated onto the incident surface; The beam splitter has a central normal line, and an angle between the incident surface and the central normal line is greater than 45° and less than 90°.

2. The virtual image display system according to claim 1, characterized in that: An included angle between the incident surface and the central normal is greater than or equal to 50° and less than or equal to 85°.

3. The virtual image display system according to claim 1, characterized in that: Two ends of the incident surface in the first direction are respectively a first end and a second end, and the first end is inclined relative to the second end toward a direction close to the beam splitter; The first direction is perpendicular to the central normal and parallel to a reference plane; the central normal is located within the reference plane, and the incident plane is perpendicular to the reference plane.

4. The virtual image display system according to claim 3, characterized in that: The center of the light emitting surface is located within the reference plane, and the light emitting surface is perpendicular to the reference plane; the two ends of the light emitting surface in the first direction are respectively a third end and a fourth end, and the third end and the first end are located on the same side of the reference line; the center of the light emitting surface is located on the reference line, and the intersection of the center normal and the incident surface is located on the reference line; The third end is inclined relative to the fourth end toward a direction away from the beam splitter.

5. The virtual image display system according to claim 4, characterized in that: The angle between the light emitting surface and the first direction is less than or equal to twice the angle between the incident surface and the first direction.

6. The virtual image display system according to claim 4 or 5, characterized in that: The center of the light emitting surface is located on a side of the center normal line close to the second end, and an angle between the center normal line and the reference line is less than or equal to twice an angle between the incident surface and the first direction.

7. The virtual image display system according to any one of claims 1 to 5, characterized in that: The display comprises: A display module, wherein the display module is used to emit a first polarized light; a first 1 / 4 wave plate, which is located between the display module and the beam splitter, and is used to convert the first polarized light emitted by the display module into the first circularly polarized light; Wherein, the surface of the first quarter wave plate facing away from the display module is the light emitting surface.

8. The virtual image display system according to any one of claims 1 to 5, characterized in that: The transflective mirror comprises: a second 1 / 4 wave plate, wherein the surface of the second 1 / 4 wave plate close to the beam splitter is the incident surface; the second 1 / 4 wave plate is used to convert the first circularly polarized light into a second linearly polarized light, and to convert the second linearly polarized light into the second circularly polarized light, and to convert the second circularly polarized light into the first linearly polarized light; A polarizing reflective film, wherein the second 1 / 4 wave plate is located between the polarizing reflective film and the beam splitter; the polarizing reflective film is used to transmit the first linear polarized light and to reflect the second linear polarized light.

9. The virtual image display system according to claim 8, characterized in that: The transflective mirror further comprises: The substrate layer, the polarizing reflective film is located between the second 1 / 4 wave plate and the substrate layer, and the polarizing reflective film is connected to the second 1 / 4 wave plate and the substrate layer.

10. The virtual image display system according to claim 1, characterized in that: The beam splitter is a curved mirror and is concave toward the direction approaching the display.

11. The virtual image display system according to claim 10, characterized in that: The beam splitter is a free-form surface mirror.

12. The virtual image display system according to claim 10 or 11, characterized in that: The spectroscope comprises: Translucent mirror; A beam splitter film is bonded to the light-transmitting mirror; the beam splitter film is used to transmit part of the first circularly polarized light emitted from the light-emitting surface, and to reflect part of the second circularly polarized light emitted from the incident surface.

13. The virtual image display system according to claim 12, characterized in that: The splitting ratio of the splitting film is 5:

5.

14. An electronic device, characterized in that: The virtual image display system comprises the virtual image display system as claimed in any one of claims 1 to 13.

15. A vehicle, characterized in that: The virtual image display system comprises the virtual image display system as claimed in any one of claims 1 to 13.

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