Pupil expanding device and head-up display device

Abstract

The invention relates to a pupil expanding device and a head-up display device, the pupil expanding device comprises a first transmission part, a second transmission part and a reflection element, the first transmission part is provided with a first semi-transparent and semi-reverse surface and a first reflection surface which are oppositely arranged, and one side, facing the first reflection surface, of the first semi-transparent and semi-reverse surface is used for receiving light emitted by an optical machine; the first reflecting surface is used for reflecting at least part of light rays entering the first reflecting surface back to the first semi-transparent and semi-reverse surface, and the reflecting element is arranged on one side, opposite to the first reflecting surface, of the first semi-transparent and semi-reverse surface; the second transmission piece is arranged on the first semi-transparent and semi-reverse side and used for reflecting at least part of light emitted by the first semi-transparent and semi-reverse side to the second transmission piece, the second transmission piece is used for carrying out pupil expansion on the light, and the pupil expansion direction of the second transmission piece intersects with the first semi-transparent and semi-reverse side. According to the invention, the exit pupil area of the image can be increased, and the size is small.

Description

Technical Field

[0001] The present application relates to the technical field of head-up display, and in particular to a pupil expansion device and a head-up display apparatus. Background Art

[0002] Pupil dilation in head-up display technology refers to the use of specific optical designs to expand the exit pupil diameter in head-up display (HUD), allowing users to clearly see the displayed content within a larger range of eye movement. This technology is particularly important in HUD because it can provide a more comfortable visual experience and a wider field of view. In related technologies, pupil dilation structures such as optical waveguides are usually used to achieve pupil dilation.

[0003] However, the pupil expansion structure in the related art usually has a large size due to its structural design requirements, making it difficult to achieve a miniaturized design of the head-up display device. Summary of the invention

[0004] Based on this, it is necessary to provide a pupil expansion device and a head-up display device to address the problem of large pupil expansion structure size in related technologies.

[0005] According to one aspect of the present application, a pupil expansion device is provided, the pupil expansion device comprising:

[0006] A first transmission member, comprising a first semi-transparent and semi-reflective surface and a first reflective surface which are arranged opposite to each other, wherein the first semi-transparent and semi-reflective surface is used to receive light emitted by the optical machine on a side facing the first reflective surface and is capable of reflecting part of the light onto the first reflective surface, and the first reflective surface is used to reflect at least part of the light incident on the first reflective surface back to the first semi-transparent and semi-reflective surface;

[0007] a second transmission member; and

[0008] A reflective element is arranged on the side of the first semi-transparent and semi-reflective surface facing away from the first reflective surface, and is used to reflect at least part of the light emitted by the first semi-transparent and semi-reflective surface onto the second transmission element, the second transmission element is used to expand the pupil of the light, and the pupil expansion direction of the second transmission element intersects with the first semi-transparent and semi-reflective surface.

[0009] In one of the embodiments, a projection of the second transmission element on a plane perpendicular to the first direction covers a projection of the first transmission element and the reflective element on a plane perpendicular to the first direction;

[0010] The first direction is parallel to the direction of the first transmission member pointing to the second transmission member.

[0011] In one embodiment, the first transmission component also includes a first substrate, a first semi-transparent and semi-reflective layer and a first reflective layer, the first semi-transparent and semi-reflective layer and the first reflective layer are respectively arranged on two opposite sides of the first substrate, the first semi-transparent and semi-reflective surface is formed on the first semi-transparent and semi-reflective layer, the first reflective surface is formed on the first reflective layer, and the first substrate is formed with a first light entrance window for receiving light emitted by the optical machine, and the first light entrance window faces the first semi-transparent and semi-reflective surface.

[0012] In one of the embodiments, at least a partial area of ​​the first semi-transmissive and semi-reflective layer includes a plurality of first light-emitting sub-regions, and at least two of the first light-emitting sub-regions are configured to have different transmittances or reflectances.

[0013] In one of the embodiments, the first semi-transmissive and semi-reflective layer further includes a first light reflecting area arranged around the plurality of first light emitting sub-areas, and the first light reflecting area is configured to reflect light of a preset wavelength.

[0014] In one embodiment, the second transmission member has a second semi-transparent and semi-reflective surface and a second reflective surface that are arranged opposite to each other, and the second reflective surface is arranged on the side of the second semi-transparent and semi-reflective surface facing the reflective element, and the second semi-transparent and semi-reflective surface is used to receive light from the reflective element and can reflect part of the light to the second reflective surface, and the second reflective surface is used to reflect at least part of the light incident on the second reflective surface back to the second semi-transparent and semi-reflective surface.

[0015] In one embodiment, the second transmission element includes a second substrate, a second semi-transparent and semi-reflective layer and a second reflective layer, the second semi-transparent and semi-reflective layer and the second reflective layer are respectively arranged on two opposite sides of the second substrate, the second semi-transparent and semi-reflective surface is formed on the second semi-transparent and semi-reflective layer, the second reflective surface is formed on the second reflective layer, the second substrate is formed with a second light incident window on the same side as the second reflective layer, and the reflective surface of the reflective element faces the second light incident window.

[0016] In one of the embodiments, the second semi-transmissive and semi-reflective layer includes a plurality of second light-emitting sub-regions, and at least two of the second light-emitting sub-regions are configured to have different transmittances or reflectances.

[0017] In one embodiment, the pupil expansion direction of the first transmission element is parallel to the second semi-transparent and semi-reflective surface.

[0018] According to another aspect of the present application, a head-up display device is provided, including an optical machine and a pupil expansion device as described in any of the above embodiments, wherein the first semi-transparent and semi-reflective surface is opposite to the light emitting side of the optical machine.

[0019] The pupil expansion device, through the cooperation of the first transmission member and the second transmission member, first expands the pupil of the imaging light in the first dimension, and then expands the pupil of the imaging light in the second dimension, so that the pupil of the imaging light can be expanded in two dimensions, greatly increasing the exit pupil area of ​​the image. At the same time, through the arrangement of the reflective element, the second transmission member can be arranged on one side of the first transmission member to achieve pupil expansion in two dimensions without occupying additional area, which can greatly reduce the size of the pupil expansion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a bottom view of a pupil expansion device in one embodiment of the present application.

[0021] Figure 2 A side view of a pupil expansion device in one embodiment of the present application from a perspective close to the optical machine.

[0022] Figure 3 This is a top perspective view of a pupil expansion device in one embodiment of the present application.

[0023] Figure 4 This is a schematic structural diagram of a first transmission component in an embodiment of the present application.

[0024] Figure 5 A side view of a pupil expansion device in an embodiment of the present application from a perspective away from the optical machine.

[0025] Fig. 6A It is a schematic diagram of imaging after the imaging light passes through the pupil expansion device in one embodiment of the present application.

[0026] Figure 6B It is a schematic diagram of imaging after the imaging light passes through the pupil expansion structure in the related art.

[0027] Description of Figure Numbers:

[0028] 100. Pupil dilation device;

[0029] 10. Optical machine;

[0030] 11, first transmission element; 111, first substrate; 112, first light entrance window; 113, first semi-transmissive and semi-reflective layer; 115A / 115B / 115C, first light emitting sub-region; 116, first light reflecting region; 117, first reflective layer;

[0031] 12. second transmission element; 121. second light incident window; 122. second semi-transmissive and semi-reflective layer; 123. second reflective layer;

[0032] 3. Reflective element;

[0033] F1, first direction. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0035] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0036] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0038] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0040] The head-up display (HUD) optical module requires several reflectors, so it is difficult to reduce the size. Therefore, it is a general trend to introduce optical waveguide technology into HUD to reduce the use of reflectors and reduce the size of the head-up display optical module. Pupil expansion technology plays an important role in optical waveguide, which allows users to clearly see the display content within a larger range of eye movement.

[0041] The geometric optical waveguide in the related art usually has a light output angle that is not perpendicular to the light output surface. If it is a one-dimensional pupil expansion, the process element (couple-in) that couples light from the light source into the optical waveguide needs to be placed close to the windshield or away from the windshield. These two sides are usually long sides. In this way, the volume of the optical element will be very large. If it is a two-dimensional pupil expansion, the pupil expansion in another dimension is prone to dark lines (blind effect) if a traditional geometric optical waveguide is used. If a diffraction optical waveguide is used, the efficiency is not high, usually only about 10%, and chromatic aberration is difficult to solve. That is, the efficiency of the pupil expansion structure in the related art, or the utilization rate of light, is low.

[0042] Based on this, the present application provides a pupil expansion device and a head-up display device, which can achieve better light utilization while expanding the exit pupil diameter, while also optimizing the structure and having a smaller size, which is conducive to miniaturized design.

[0043] See also Figure 1 , Figure 2 and Figure 3 As shown, Figure 1 It is a bottom view of the pupil expansion device 100 in one embodiment of the present application. Figure 2 This is a side view of the pupil expansion device 100 in one embodiment of the present application from a perspective close to the optical machine 10. Figure 3 1 is a top perspective view of a pupil expansion device 100 in one embodiment of the present application.

[0044] The pupil dilation device 100 provided in the present application includes a first transmission component 11, a second transmission component 12 and a reflective element 3. The pupil dilation device 100 of the present application is arranged on the light-emitting side of the optical machine 10, and emits imaging light through the optical machine 10. Among them, the first transmission component 11 is arranged on the light-emitting side of the optical machine 10, and first receives the imaging light. The first transmission component 11 has a first semi-transparent and semi-reflective surface and a first reflective surface that are relatively arranged. The side of the first semi-transparent and semi-reflective surface facing the first reflective surface is used to receive the light emitted by the optical machine, and can reflect part of the light onto the first reflective surface. The first reflective surface is used to reflect at least part of the light incident on the first reflective surface back to the first semi-transparent and semi-reflective surface. Thereby, the imaging light emitted by the optical machine 10 is pupil dilated in the first dimension through the first transmission component 11. It can be understood that the imaging light emitted by the optical machine 10 enters the first transmission element 11 and is first incident on the first semi-transparent and semi-reflective surface, and part of the imaging light passes through the first semi-transparent and semi-reflective surface, and the remaining part of the light is reflected by the first semi-transparent and semi-reflective surface to the first reflective surface, and part of the light reflected to the first reflective surface is then reflected by the first reflective surface to the first semi-transparent and semi-reflective surface, and part of the light passes through the first semi-transparent and semi-reflective surface, and the remaining part of the light is reflected by the first semi-transparent and semi-reflective surface to the first reflective surface. In this way, part of the imaging light is repeatedly reflected back and forth between the first semi-transparent and semi-reflective surface and the first reflective surface, and in the process of back and forth reflection, part of the light incident on the first semi-transparent and semi-reflective surface can pass through the first semi-transparent and semi-reflective surface, thereby performing transverse beam expansion on the imaging light to obtain a one-dimensional expanded beam. Therefore, the imaging light has a relatively increased exit pupil area after pupil expansion in the first dimension.

[0045] The second transmission member 12 is disposed on one side of the first transmission member 11, and is used to dilate the pupil of the light passing through the first transmission member 11 in a second dimension. It can be understood that the second dimension is another dimension different from the first dimension. After the imaging light passes through the pupil dilation in the first dimension, it passes through the pupil dilation in the second dimension again, so that the imaging light emitted by the optical machine 10 can be dilated in two dimensions through the first transmission member 11 and the second transmission member 12, which greatly increases the exit pupil area of ​​the image.

[0046] The reflective element 3 is arranged on the side of the first semi-transparent and semi-reflective surface facing away from the first reflective surface, and is used to reflect at least part of the light emitted from the first semi-transparent and semi-reflective surface onto the second transmission element 12, and the pupil expansion direction of the second transmission element intersects with the first semi-transparent and semi-reflective surface. The light is dilated in the second dimension through the second transmission element 12. It can be understood that, through the arrangement of the reflective element 3, the positions of the first transmission element 11 and the reflective element 3 can be located on the same side of the second transmission element 12, that is, the side of the first semi-transparent and semi-reflective surface facing away from the first reflective surface, which is conducive to reducing the lateral size of the pupil expansion device 100, and allowing the light emitted from the first transmission element 11 to smoothly enter the second transmission element 12, so that the pupil expansion device 100 can perform two-dimensional pupil expansion on the imaging light and increase the exit pupil area of ​​the image.

[0047] It can be understood that the first dimension of the pupil expansion performed by the first transmission member 11 on the imaging light in the first dimension, or the direction of the pupil expansion performed by the first transmission member 11, is parallel to the first semi-transparent and semi-reflective surface, and the pupil expansion direction of the second transmission member 12 is parallel to the second semi-transparent and semi-reflective surface, so as to expand the exit pupil area in these two dimensions. In some embodiments, the two pupil expansion directions not only intersect but also can be perpendicular to each other, and no excessive restrictions are made here.

[0048] In some embodiments, the projection of the second transmission element 12 on the plane perpendicular to the first direction F1 covers the projections of the first transmission element 11 and the reflective element 3 on the plane perpendicular to the first direction F1. In other words, the plane perpendicular to the first direction F1 is defined as a reference plane, and the projection of the second transmission element 12 on the reference plane covers the projections of the first transmission element 11 and the reflective element 3 on the reference plane, wherein the first direction F1 is parallel to the direction of the first transmission element 11 pointing to the second transmission element 12. Figure 2 As shown, in this embodiment, the first transmission member 11 and the reflective element 3 are both located on the same side of the second transmission member 12 along the first direction F1, so that the lateral size of the pupil expansion device 100 is the size of the second transmission member 12, and the first transmission member 11 and the reflective element 3 do not occupy additional size, thereby being able to greatly reduce the lateral size of the pupil expansion device 100, which is conducive to the miniaturization design of the pupil expansion device 100.

[0049] In some embodiments, the first direction can be parallel to the first semi-transparent and semi-reflective surface, and at the same time parallel to the first reflective surface, and also perpendicular to the second semi-transparent and semi-reflective surface and the second reflective surface. In this embodiment, the first semi-transparent and semi-reflective surface can be parallel to the first reflective surface, and the second semi-transparent and semi-reflective surface can be parallel to the second reflective surface, and no excessive restrictions are made here.

[0050] In some embodiments, in conjunction with Figure 4 As shown, Figure 4This is a schematic diagram of the structure of the first transmission component 11 in an embodiment of the present application. The first transmission component 11 also includes a first substrate 111. The first semi-transparent and semi-reflective surface and the first reflective surface are respectively arranged on both sides of the first substrate 111 along the light emitting direction of the optical machine 10. The first substrate 111 includes a first light entrance window 112. The first light entrance window 112 faces the first semi-transparent and semi-reflective surface. The optical machine 10 is arranged at the first light entrance window 112 to emit imaging light into the first substrate 111. The first light entrance window 112 can be on the same side as the first reflective surface. The arrangement of the first substrate 111 is conducive to improving the propagation efficiency of the light propagating therein, and is conducive to improving the utilization rate of the light. The first semi-transparent and semi-reflective layer 113 and the first reflective layer 117 can be coated on both sides of the first substrate 111 by a coating process, thereby forming the first semi-transparent and semi-reflective surface and the first reflective surface, which is conducive to improving the convenience of preparation and reducing the preparation cost.

[0051] In some embodiments, the pupil expansion direction of the first transmission element 11 is parallel to the second semi-transparent and semi-reflective surface. It can also be understood that the first substrate 111 has an extension direction, and the extension direction of the first substrate 111 is parallel to the reference plane. Figure 3 The extension direction of the first substrate 111 can also be understood as the overall propagation direction of the light in the first transmission member 11. In this way, the first substrate 111 extends horizontally and does not occupy too much vertical space, or does not occupy much space along the first direction F1. Therefore, the pupil expansion device 100 of the present application has better integration characteristics in both the horizontal and vertical directions, occupies less space, and is conducive to realizing the miniaturization design of the pupil expansion device 100.

[0052] In some embodiments, the first substrate 111 may be made of glass or plastic, which has the advantages of low cost and easy shaping.

[0053] In some embodiments, the first transmission member further includes a first semi-transmissive and semi-reflective layer 113, and the first semi-transmissive and semi-reflective layer 113 is provided on one side of the first substrate 111 along the light emitting direction of the optical machine 10, and the first semi-transmissive and semi-reflective surface is formed on the first semi-transmissive and semi-reflective layer 113. In this embodiment, the first semi-transmissive and semi-reflective layer 113 can be formed on the first substrate 111 by optical coating.

[0054] At least part of the first semi-transmissive and semi-reflective layer 113 includes a plurality of first light-emitting sub-regions, at least two of which are configured to transmit light of different wavelengths, that is, at least two of which are configured to have different transmittances, or at least two of which are configured to have different reflectances. That is, different first light-emitting sub-regions of the first semi-transmissive and semi-reflective layer 113 can be designed to reflect light of specific wavelengths according to actual design requirements, such as Figure 4In the embodiment, the first light-emitting sub-region 115A can reflect light of the first wavelength band and transmit light of other wavelength bands, the first light-emitting sub-region 115B can reflect light of the second wavelength band and transmit light of other wavelength bands, and the first light-emitting sub-region 115C can reflect light of the third wavelength band and transmit light of other wavelength bands. The first wavelength band, the second wavelength band and the third wavelength band are different wavelength bands. The specific design can be based on specific needs, such as reflecting red light, green light or light of other wavelength bands separately.

[0055] In some embodiments, continue to refer to Figure 4 As shown, the first semi-transmissive and semi-reflective layer 113 also includes a first light reflecting area 116 arranged around the plurality of first light emitting sub-areas, and the first light reflecting area 116 enables the light incident thereon to be reflected back into the first substrate 111, so that the light can be emitted within a preferred light emitting range, which is beneficial to improving the utilization rate of the light. The first light reflecting area 116 is configured to reflect light of a preset wavelength.

[0056] In some embodiments, optical film layers with different parameters may be deposited at different positions on one side of the first substrate 111 to form a first semi-transmissive and semi-reflective layer 113 having a first light emitting area 114 and a first light reflecting area 116 .

[0057] In some embodiments, continue to refer to Figure 4 As shown, a first reflective layer 117 is provided on the side of the first substrate 111 away from the first semi-transmissive and semi-reflective layer 113, that is, the first semi-transmissive and semi-reflective layer 113 and the first reflective layer 117 are respectively provided on two opposite sides of the first substrate 111. The first reflective surface is formed on the first reflective layer 117. The first reflective layer 117 can be configured to reflect light of a specific wavelength. Thereby cooperating with the above-mentioned first semi-transmissive and semi-reflective layer 113 to achieve pupil expansion of the imaging light in the first dimension. The first substrate 111 is formed with the above-mentioned first light entrance window 112 on the same side as the first reflective layer 117 and for receiving light emitted by the optical machine.

[0058] In some embodiments, continue to refer to Figure 1 As shown, the first semi-transparent and semi-reflective surface is tilted with respect to the light emitting direction of the optical machine 10 , so that light can be incident into the first substrate 111 at a preset angle, and part of the light can be repeatedly reflected along its overall direction or the extension direction of the first substrate 111 .

[0059] In some embodiments, see Figure 5 As shown, Figure 5This is a side view of the pupil expansion device 100 in one embodiment of the present application from a perspective away from the optical machine 10. Similar to the first output element 11, the second transmission element 12 has a second semi-transparent and semi-reflective surface and a second reflective surface that are arranged opposite to each other. The second reflective surface is arranged on the side of the second semi-transparent and semi-reflective surface facing the reflective element 3. The second semi-transparent and semi-reflective surface is used to receive light from the reflective element 3 and can reflect part of the light to the second reflective surface. The second reflective surface is used to reflect at least part of the light incident on the second reflective surface back to the second semi-transparent and semi-reflective surface. This is to achieve pupil expansion in the second dimension for the imaging light emitted by the first transmission element.

[0060] In some embodiments, see Figure 5 As shown, the second transmission element 12 includes a second substrate, a second semi-transparent and semi-reflective layer 122 and a second reflective layer 123. The second semi-transparent and semi-reflective layer 122 and the second reflective layer 123 are respectively arranged on two opposite sides of the second substrate or on two sides along the first direction F1. The second semi-transparent and semi-reflective surface is formed on the second semi-transparent and semi-reflective layer 122, and the second reflective surface is formed on the second reflective layer 123. The second substrate includes a second light incident window 121 on the same side as the second reflective layer 123, and the reflective surface of the reflective element faces the second light incident window 121.

[0061] It can be understood that the imaging light emitted from the first transmission element 11 enters the second substrate and is first incident on the second semi-transmissive and semi-reflective layer 122, and part of the imaging light passes through the second semi-transmissive and semi-reflective layer 122, and the remaining part of the light is reflected by the second semi-transmissive and semi-reflective layer 122 to the second reflective layer 123, and part of the light reflected to the second reflective layer 123 is reflected by the second reflective layer 123 to the second semi-transmissive and semi-reflective layer 122, and part of the light passes through the second semi-transmissive and semi-reflective layer 122, and the remaining part of the light is reflected by the second semi-transmissive and semi-reflective layer 122 to the second reflective layer 123. In this way, part of the imaging light emitted from the first transmission element 11 is repeatedly reflected back and forth between the second semi-transmissive and semi-reflective layer 122 and the second reflective layer 123, and in the process of back and forth reflection, part of the light incident on the second semi-transmissive and semi-reflective layer 122 can also pass through the second semi-transmissive and semi-reflective layer 122, thereby expanding the imaging light beam in the second dimension to obtain a two-dimensional expanded light beam. Thus, the imaging light has a relatively larger exit pupil area after the pupil is expanded in the first dimension and the pupil is expanded in the second dimension. The second substrate, the second semi-transmissive and semi-reflective layer 122 and the second reflective layer 123 are arranged similarly to the first substrate 111, the first semi-transmissive and semi-reflective layer 113 and the first reflective layer 117, and can be referred to Figure 4 , I will not go into details here.

[0062] Among them, the setting of the second substrate is conducive to improving the propagation efficiency of light propagating therein, and is conducive to improving the utilization rate of light. The second semi-transparent and semi-reflective layer 122 and the second reflective layer 123 can be coated on both sides of the second substrate by a coating process, which is conducive to improving the convenience of preparation and reducing the preparation cost.

[0063] In this embodiment, the second semi-transmissive and semi-reflective layer 122 and the second reflective layer 123 can be formed on the first substrate 111 by optical coating.

[0064] In some embodiments, the first reflective surface is formed on the side of the first reflective layer 117 facing the first semi-transmissive reflective layer 113, the first semi-transmissive reflective surface is formed on the side of the first semi-transmissive reflective layer 113 facing the first reflective layer 117, the second reflective surface is formed on the side of the second reflective layer 123 facing the second semi-transmissive reflective layer 122, and the second semi-transmissive reflective surface is formed on the side of the second semi-transmissive reflective layer 122 facing the second reflective layer 123. This is conducive to reducing the loss of light propagating in the reflective layer and the semi-transmissive reflective layer, and is conducive to improving the light utilization rate.

[0065] In some embodiments, the second substrate may also be made of glass or plastic, which has the advantages of low cost and easy shaping.

[0066] In some embodiments, the second semi-transparent and semi-reflective layer 122 includes a plurality of second light-emitting sub-areas and a second light-reflecting area, and the second light-reflecting area is arranged on the peripheral side of the plurality of second light-emitting sub-areas. At least two second light-emitting sub-areas are configured to transmit light of different wavelengths, that is, at least two second light-emitting sub-areas are configured to have different transmittances, or at least two second light-emitting sub-areas are configured to have different reflectivities. That is, the different second light-emitting sub-areas of the second semi-transparent and semi-reflective layer 122 can be designed to reflect light of specific wavelengths respectively according to actual design requirements. It can be specifically designed according to specific requirements, such as reflecting red light, green light or light of other wavelengths separately. The second light-reflecting area enables the light incident thereon to be reflected back into the second substrate, so that the light can be emitted within a better light-emitting range, which is conducive to improving the utilization rate of the light.

[0067] In some embodiments, optical film layers with different parameters may be deposited at different positions on one side of the second substrate to form a second semi-transmissive and semi-reflective layer 122 having a second light emitting region and a second light reflecting region.

[0068] In some embodiments, the second reflective layer 123 and the second reflective area are configured to reflect light of a specific wavelength, thereby cooperating with the second semi-transmissive and semi-reflective layer 122 to achieve pupil expansion in the second dimension for the imaging light.

[0069] The present application also provides a head-up display device, including the pupil expansion device 100, the optical machine 10 and the housing in any of the above embodiments, wherein the pupil expansion device 100 and the optical machine 10 are both arranged in the housing, and the pupil expansion device 100 is arranged on the light exit side of the optical machine. The head-up display device provided by the present application greatly increases the exit pupil area of ​​the image through the pupil expansion device 100, and has a smaller size, which is conducive to the miniaturization design of the head-up display device.

[0070] The pupil expansion device 100 and the head-up display device of the present application, through the cooperation of the first transmission member 11 and the second transmission member 12, first expand the pupil of the imaging light in the first dimension, and then expand the pupil of the imaging light in the second dimension, so that the pupil of the imaging light can be expanded in two dimensions, which greatly increases the exit pupil area of ​​the image. At the same time, through the setting of the reflective element 3, the second transmission member 12 can be set on one side of the first transmission member 11 to achieve pupil expansion in two dimensions without occupying additional area, which can greatly reduce the size of the pupil expansion device 100. Fig. 6A and Figure 6B As shown, Fig. 6A It is a schematic diagram of imaging after the imaging light passes through the pupil expansion device in one embodiment of the present application. Figure 6B It is a schematic diagram of imaging after the imaging light passes through the pupil expansion structure in the related art. It can be seen that the pupil expansion device 100 of the present application can also improve the uniformity and brightness of the image, and it can be seen that the pupil expansion device 100 of the present application has a better pupil expansion effect on the imaging light.

[0071] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A pupil expansion device, characterized in that: The pupil expansion device comprises: A first transmission member, comprising a first semi-transparent and semi-reflective surface and a first reflective surface which are arranged opposite to each other, wherein the first semi-transparent and semi-reflective surface is used to receive light emitted by the optical machine on a side facing the first reflective surface and is capable of reflecting part of the light onto the first reflective surface, and the first reflective surface is used to reflect at least part of the light incident on the first reflective surface back to the first semi-transparent and semi-reflective surface; a second transmission member; and A reflective element is arranged on the side of the first semi-transparent and semi-reflective surface facing away from the first reflective surface, and is used to reflect at least part of the light emitted by the first semi-transparent and semi-reflective surface onto the second transmission element, the second transmission element is used to expand the pupil of the light, and the pupil expansion direction of the second transmission element intersects with the first semi-transparent and semi-reflective surface.

2. The pupil expansion device according to claim 1, characterized in that: The projection of the second transmission member on the plane perpendicular to the first direction covers the projections of the first transmission member and the reflective element on the plane perpendicular to the first direction; The first direction is parallel to the direction of the first transmission member pointing to the second transmission member.

3. The pupil expansion device according to claim 2, characterized in that: The first transmission component also includes a first substrate, a first semi-transparent and semi-reflective layer and a first reflective layer. The first semi-transparent and semi-reflective layer and the first reflective layer are respectively arranged on two opposite sides of the first substrate. The first semi-transparent and semi-reflective surface is formed on the first semi-transparent and semi-reflective layer. The first reflective surface is formed on the first reflective layer. The first substrate is formed with a first light entrance window for receiving light emitted by the optical machine, and the first light entrance window faces the first semi-transparent and semi-reflective surface.

4. The pupil expansion device according to claim 3, characterized in that: At least a partial area of ​​the first semi-transmissive and semi-reflective layer includes a plurality of first light-emitting sub-regions, and at least two of the first light-emitting sub-regions are configured to have different transmittances or reflectances.

5. The pupil expansion device according to claim 4, characterized in that: The first semi-transmissive and semi-reflective layer further includes a first light reflecting area arranged around the plurality of first light emitting sub-areas, and the first light reflecting area is configured to reflect light of a preset wavelength.

6. The pupil expansion device according to claim 1, characterized in that: The second transmission component has a second semi-transparent and semi-reflective surface and a second reflective surface that are arranged opposite to each other. The second reflective surface is arranged on the side of the second semi-transparent and semi-reflective surface facing the reflective element. The second semi-transparent and semi-reflective surface is used to receive light from the reflective element and can reflect part of the light to the second reflective surface. The second reflective surface is used to reflect at least part of the light incident on the second reflective surface back to the second semi-transparent and semi-reflective surface.

7. The pupil expansion device according to claim 6, characterized in that: The second transmission component includes a second substrate, a second semi-transmissive and semi-reflective layer and a second reflective layer, the second semi-transmissive and semi-reflective layer and the second reflective layer are respectively arranged on two opposite sides of the second substrate, the second semi-transmissive and semi-reflective surface is formed on the second semi-transmissive and semi-reflective layer, the second reflective surface is formed on the second reflective layer, the second substrate is formed with a second light incident window on the same side as the second reflective layer, and the reflective surface of the reflective element faces the second light incident window.

8. The pupil expansion device according to claim 7, characterized in that: The second semi-transmissive and semi-reflective layer includes a plurality of second light-emitting sub-regions, and at least two of the second light-emitting sub-regions are configured to have different transmittances or reflectances.

9. The pupil expansion device according to claim 6, characterized in that: The pupil expansion direction of the first transmission element is parallel to the second semi-transparent and semi-reflective surface.

10. A head-up display device, characterized in that: It comprises an optical machine and a pupil expansion device as described in any one of claims 1 to 9, wherein the first semi-transmissive and semi-reflective surface is opposite to the light output side of the optical machine.

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