Display device, head-up display and motor vehicle

Abstract

Provided are a display device, a head-up display, and a motor vehicle. The display device includes a light source portion, a converging element, a diffusing element, a liquid crystal display panel, and a reflecting element; the light source portion is configured to emit light; the light emitted from the light source portion passes through the converging element, the diffusing element, the liquid crystal display panel, and the reflecting element to reach a first predetermined region; the converging element is configured to converge light passing through the converging element; the diffusing element is configured to diffuse a light beam passing through the diffusing element but not to change an optical axis of the light beam; the liquid crystal display panel is configured to convert light received thereby into image light and emit the image light; the reflecting element is configured to reflect and converge the image light; and the converging element is configured to, in the case where the diffusing element is removed from a light path from the light source portion to the first predetermined region, collect the light emitted from the light source portion into a second predetermined region within the first predetermined region, the second predetermined region having an area smaller than that of the first predetermined region. The display device can reduce power consumption and improve brightness.

Description

Technical Field

[0001] At least one embodiment of this disclosure relates to a display device, a head-up display, and a motor vehicle. Background Technology

[0002] A head-up display (HUD) uses a reflective optical design to project the light emitted from an image source onto an imaging window (image panel, windshield, etc.). The driver can see the image directly without looking down, avoiding the distraction caused by looking down at the instrument panel while driving, improving driving safety, and also providing a better driving experience. Summary of the Invention

[0003] At least one embodiment of this disclosure relates to a display device, a head-up display, and a motor vehicle.

[0004] At least one embodiment of this disclosure provides a display device including a light source, a converging element, a diffuser element, a liquid crystal display panel, and a reflective element; the light source is configured to emit light, and the light emitted from the light source passes through the converging element, the diffuser element, the liquid crystal display panel, and the reflective element to reach a first predetermined area; the converging element is configured to converge the light passing through the converging element; the diffuser element is configured to diffuse the light beam passing through the diffuser element without changing the optical axis of the light beam; the liquid crystal display panel is configured to convert the light it receives into image light and emit it; the reflective element is configured to reflect the image light and converge the image light; the converging element is configured to, when the diffuser element is removed from the optical path from the light source to the first predetermined area, focus the light emitted from the light source into a second predetermined area within the first predetermined area, the area of ​​the second predetermined area being smaller than the area of ​​the first predetermined area.

[0005] According to some embodiments of the present disclosure, the display device further includes a reflective element that reflects the image light before it reaches the first predetermined area, and the reflected light from the reflective element reaches the first predetermined area.

[0006] According to some embodiments of the present disclosure, in a display device, the diffusion element is located between the converging element and the liquid crystal display panel.

[0007] According to some embodiments of the present disclosure, the diffusion element has a diffusion angle ranging from 5° to 20° in a first direction, where the first direction is parallel to the diffusion element.

[0008] According to some embodiments of the present disclosure, the diffusion element has a diffusion angle range of 5° to 10° in a second direction, the second direction being parallel to the diffusion element and perpendicular to the first direction.

[0009] According to some embodiments of the present disclosure, the first direction and the second direction are both perpendicular to the arrangement direction of the converging element, the diffuser element and the liquid crystal display panel.

[0010] According to some embodiments of the present disclosure, the display device includes a light source and a reflective light guide element. The light source is configured to emit light, and the reflective light guide element is configured to reflect a portion of the light emitted by the light source that is incident on the reflective light guide element so that it is incident on the converging element.

[0011] According to some embodiments of the present disclosure, the reflective light guide element has a light inlet, the light source part further includes a light source substrate, the light source substrate is disposed at the light inlet, the light source is disposed on the light source substrate, and the light source substrate is inclined relative to the liquid crystal display panel.

[0012] According to some embodiments of the present disclosure, the angle between the light source substrate and the liquid crystal display panel is greater than 5° and less than or equal to 30°.

[0013] According to some embodiments of the present disclosure, the reflective light guide element has a light outlet, the light inlet and the light outlet are disposed opposite to each other, and the light inlet is disposed at an angle relative to the light outlet.

[0014] According to some embodiments of the present disclosure, the area of ​​the light inlet is smaller than the area of ​​the light outlet, the light inlet is trapezoidal in shape, and the light outlet is rectangular in shape.

[0015] According to some embodiments of the present disclosure, the reflective light guide element includes a first surface and a second surface, the first surface and the second surface are disposed opposite to each other, the angle between the first surface and the liquid crystal display panel is greater than the angle between the second surface and the liquid crystal display panel, the first surface is a surface including a trapezoidal light entrance port upper base, the second surface is a surface including a trapezoidal light entrance port lower base, and the length of the upper base of the trapezoid is less than the length of the lower base of the trapezoid.

[0016] According to some embodiments of the present disclosure, the light source unit further includes a collimating element located between the light source and the converging element, and the collimating element is configured to adjust a portion of the light emitted by the light source incident on the collimating element into collimated light.

[0017] According to some embodiments of the present disclosure, in the display device, the collimating element is located inside the reflective light guide element, and the maximum size of the collimating element is smaller than the size of the light outlet of the reflective light guide element; or, the collimating element is located outside the reflective light guide element, and the maximum size of the collimating element is greater than or equal to the size of the light outlet of the reflective light guide element.

[0018] According to some embodiments of the present disclosure, the converging element includes at least one of a convex lens, a Fresnel lens, and a lens combination.

[0019] According to some embodiments of the present disclosure, the diffusion element of the display device includes at least one of a diffractive optical element and a scattering optical element.

[0020] According to some embodiments of the present disclosure, the liquid crystal display panel includes a liquid crystal cell and a first polarizer and a second polarizer disposed on both sides of the liquid crystal cell. The first polarizer is located on the side of the liquid crystal cell closer to the diffusion element, and the second polarizer is located on the side of the liquid crystal cell away from the diffusion element.

[0021] According to some embodiments of the present disclosure, the display device further includes a polarization control element located between the light source and the liquid crystal display panel, wherein the transmission axis direction of the polarization control element is the same as the transmission axis direction of the first polarizer.

[0022] According to some embodiments of the present disclosure, the reflective element of the display device includes a curved mirror or a combination of a plane mirror and a curved mirror.

[0023] At least one embodiment of this disclosure also provides a head-up display, including any of the above-described display devices.

[0024] At least one embodiment of this disclosure also provides a motor vehicle including any of the above-described display devices. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0026] Figure 1 This is a schematic diagram of a HUD device;

[0027] Figure 2A This is a schematic diagram of a display device provided according to an embodiment of the present disclosure;

[0028] Figure 2BA schematic diagram of a display device provided in another embodiment of this disclosure;

[0029] Figure 2C A schematic diagram of a display device provided in another embodiment of this disclosure;

[0030] Figure 3 A schematic diagram of a first predetermined area and a second predetermined area in a display device provided according to an embodiment of the present disclosure;

[0031] Figure 4 A schematic diagram of a converging element in a display device according to an embodiment of this disclosure;

[0032] Figure 5 A schematic diagram of a diffusion element in a display device according to an embodiment of this disclosure;

[0033] Figure 6 This is a schematic diagram illustrating the diffusion of a light beam through a diffusion element in a display device according to an embodiment of this disclosure.

[0034] Figure 7 This is a schematic diagram of a light source section in a display device according to an embodiment of the present disclosure;

[0035] Figure 8 This is a schematic diagram of a display device having a collimation element according to an embodiment of the present disclosure;

[0036] Figures 9A to 9D This is a schematic diagram of a light source unit in a display device provided in some embodiments of the present disclosure;

[0037] Figure 10 A schematic diagram of a display device provided in another embodiment of this disclosure;

[0038] Figures 11A to 11D This is a schematic diagram of a light source unit in a display device provided in some embodiments of the present disclosure;

[0039] Figure 12 A schematic diagram of a liquid crystal display panel in a display device provided for some embodiments of this disclosure; and

[0040] Figure 13 This is a schematic diagram of a display device provided for some embodiments of the present disclosure. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0042] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as “including” or “comprising” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0043] Typical HUDs are based on reflection imaging using plane mirrors and curved mirrors. The light emitted from the HUD's image source is reflected sequentially by the plane mirror and the curved mirror before exiting behind the imaging window to form an image.

[0044] Figure 1 This is a schematic diagram of a HUD device. Figure 1 As shown, the HUD device includes an image source 01, a reflective element 02, and a transflective element 03. The image source 01 includes a light source 011, a reflector 012, and a display panel 013. Part of the light emitted from the light source 011 is directly incident on the display panel 013, and part is reflected by the reflector 012. The light incident on the display panel 013 is converted into image light and emitted. The image light is incident on the reflective element 02, reflected by the reflective element 02 to the transflective element 03, and then reflected by the transflective element 03 to form an image. Figure 1 The eyebox region EB0 is shown. A human eye located within the eyebox region EB0 can observe a virtual image located on the other side of the transflective element 03.

[0045] like Figure 1 As shown, the image source of a HUD device is generally just a reflector cup 012 set in the light-emitting direction of the light source 011. The light emitted by the light source is controlled by the reflector cup alone. However, the light control effect of the reflector cup is poor. Some light rays have a large emission angle, which causes some light rays to fail to reach the eye box area EB0 and thus cannot be effectively utilized. Figure 1After the light beam L01 is reflected by the reflector 012, its large exit angle prevents it from reaching the eye box area EB0, thus wasting some of the light emitted by the light source. This results in low light utilization, low overall light efficiency, and insufficient screen brightness in typical HUD devices, while achieving sufficient screen brightness requires high power consumption. Furthermore, even by narrowing the light exit aperture of the reflector to reduce its exit angle range, the emitted light may still have irregular angles and fail to reach the intended observation area, further reducing light utilization efficiency.

[0046] Therefore, when the light emitted by the light source is controlled solely by the reflector cup, some light cannot reach the eye box area EB0, resulting in low brightness in the eye box area EB0, or the power consumption of the light source 011 is high in order to make the eye box area EB0 have sufficient brightness.

[0047] Figure 2A This is a schematic diagram of a display device provided according to an embodiment of the present disclosure. Figure 2A As shown, the image source 10 includes a light source 101, a converging element 102, a diffusing element 103, a liquid crystal display panel 104, and a reflective element 20. For example... Figure 2A As shown, the light source 101 is configured to emit light. The light emitted from the light source 101 passes through the converging element 102, the diffusing element 103, the liquid crystal display panel 104, and the reflecting element 20 before reaching the first predetermined area R1. The first predetermined area R1 is a planar observation area.

[0048] like Figure 2A As shown, the converging element 102 is configured to converge the light passing through it. Figure 2A As shown, the light emitted from the light source 101 is focused by the focusing element 102, so that more light can reach the first predetermined area R1, thereby improving the light utilization rate. The focusing element 102 changes the optical axis of the light beam to converge multiple light rays, making the propagation direction of the light controllable, so that more light rays can reach the first predetermined area R1. For example, the focusing element 102 can focus the light rays so that multiple light rays can be focused to a single point, but it is not limited to this.

[0049] like Figure 2AAs shown, the diffuser element 103 is configured to diffuse the light beam passing through it without altering the optical axis of the beam. Light focused by the converging element 10 is diffused by the diffuser element 103 to expand the observation area. The light rays in the beam passing through the diffuser element 103 disperse outwards, but the optical axis of the beam remains unchanged. For example, the primary propagation direction of the light passing through the diffuser element 103 remains unchanged. For example, the cross-sectional area of ​​the beam incident on the diffuser element 103 is smaller than the cross-sectional area of ​​the beam after passing through the diffuser element 103. For example, in embodiments of this disclosure, "optical axis" refers to the centerline of the beam, which may refer to the primary propagation direction of the light.

[0050] like Figure 2A As shown, the liquid crystal display panel 104 is configured to convert the light it receives into image light for emission. Figure 2A As shown, light is diffused by the diffusion element 103 and then incident on the liquid crystal display panel 104, forming image light L10 after passing through the liquid crystal display panel 104.

[0051] like Figure 2A As shown, the reflecting element 20 is configured to reflect and converge the image light L10. For example, the reflecting element 20 is a mirror or a combination of mirrors, including at least one curved mirror. The reflecting element can be a curved mirror, or a combination of a plane mirror and a curved mirror, such as... Figure 2A The following explanation uses a curved reflector as an example; a freeform reflector can be used. The purpose of setting up a curved reflector is to further concentrate the light, ensuring that all light rays are ultimately focused within the first predetermined area R1, thereby improving the light utilization rate of the display device. Furthermore, a plane mirror can be added to the curved reflector to fold the light path and save installation space. For example, a freeform surface can refer to a surface that cannot be mathematically represented by a simple surface function. In the embodiments of this disclosure, a freeform reflector can be used to concentrate more light rays into the first predetermined area R1.

[0052] like Figure 2A As shown, the display device includes an image source 10, which is configured to emit image light L10. For example, as Figure 2A As shown, the display device also includes a reflective element 30, which reflects the image light L10 before it reaches the first predetermined area R1. For example, as Figure 2A As shown, before the image light L10 reaches the reflective element 30, it is reflected by the reflective element 20 to change its propagation direction. For example, the image light L10 is reflected by the reflective element 20 to the reflective element 30, and then reflected by the reflective element 30 to the first predetermined region R1. Figure 2A The image light L10 is shown as reflected light LR1 obtained by reflecting the image light L10 by the reflective element 20. The reflected light LR1 is incident on the transflective element 30 to obtain reflected light LR2, and the reflected light LR2 is emitted to the first predetermined area R1.

[0053] For example, the reflective element 30 can be a windshield or an imaging window. Imaging through the windshield results in a W-HUD (windshield-HUD), while imaging through the imaging window results in a C-HUD. The imaging window is generally a curved imaging plate made of transparent material with a certain curvature. Because the windshield is a free-form surface, the windshield or the curved imaging window will further control the light, causing the reflected light to converge towards the first predetermined area R1. Optionally, when the reflective element is a windshield, a wedge-shaped film can be added. The wedge-shaped film is set in the interlayer of the windshield, and the wedge-shaped film can eliminate ghosting.

[0054] like Figure 2A As shown, the converging element 102 is configured to focus the light emitted from the light source 101 onto a second predetermined region R2 within the first predetermined region R1 when the diffuser element 103 is removed from the optical path from the light source 101 to the first predetermined region R1. The area of ​​the second predetermined region R2 is smaller than the area of ​​the first predetermined region R1. For example, in embodiments of this disclosure, removing the diffuser element 103 from the optical path from the light source 101 to the first predetermined region R1 means that, compared to the case where the diffuser element 103 is not removed from the optical path from the light source 101 to the first predetermined region R1, only the diffuser element 103 is removed from the optical path from the light source 101 to the first predetermined region R1, while other elements besides the diffuser element 103 are retained. For example, Figure 2A In the display device shown, the case where the diffusion element 103 is removed from the light path from the light source 101 to the first predetermined area R1 is the case where the diffusion element 103 is removed, and the light source 101, the converging element 102, the liquid crystal display panel 104, the reflective element 20, and the transflective element 30 are retained.

[0055] Figure 2B This is a schematic diagram of a display device provided for another embodiment of this disclosure. Figure 2A Compared to the display device shown, Figure 2B The display device in the middle does not have a reflective element 30. Of course, it can also be... Figure 2B The display device in the middle is equipped with a reflective element 30.

[0056] For example, the display device could be a head-up display (HUD). Figure 2A The display device shown is a head-up display. Figure 2B The display device shown is a head-up display consisting of an image source and a reflective element. The following explanation uses a head-up display as an example.

[0057] The aforementioned phrase "light emitted from the light source 101 can reach the first predetermined area R1 after passing through the converging element 102, the diffuser 103, the liquid crystal display panel 104, and the reflective element 20" can refer to light emitted from the light source 101 directly reaching the first predetermined area R1 after passing through the converging element 102, the diffuser 103, the liquid crystal display panel 104, and the reflective element 20 (e.g., light emitted from the light source 101 can directly reach the first predetermined area R1 after passing through the converging element 102, the diffuser 103, the liquid crystal display panel 104, and the reflective element 20). Figure 2B As shown), it can also reach the first predetermined area R1 after being processed by other optical elements (such as...). Figure 2A (As shown).

[0058] Figure 2C This is a schematic diagram of a display device provided in another embodiment of the present disclosure. Figure 2C The image shows the mirror position R11 of the first predetermined region R1 relative to the transflective element 30, the mirror position R21 of the second predetermined region R2 relative to the transflective element 30, and the mirror position EB1 of the eye box region EB relative to the transflective element 30. Figure 2C The display device shown is illustrated using a plane mirror as the reflective element. However, the reflective element is not limited to a plane mirror. For example, the reflective element can also be a curved surface, and more specifically, a free-form surface. For instance, when the reflective element adopts a free-form surface, it is more conducive to focusing the reflected light onto the eye box area EB.

[0059] The aforementioned "first predetermined area" refers to a planar observation area. Light emitted from the light source unit 101 passes through the converging element 102, the diffusing element 103, the liquid crystal display panel 104, and the reflecting element 20 before reaching the plane where the first predetermined area is located. Most of the light is concentrated in the first predetermined area of ​​this plane (for example, more than 90% of the light intensity of the light beam incident on the plane where the first predetermined area is located is concentrated in the first predetermined area, or more than 80% of the light intensity of the light beam incident on the plane where the first predetermined area is located is concentrated in the first predetermined area, or more than 60% of the light intensity of the light beam incident on the plane where the first predetermined area is located is concentrated in the first predetermined area), and the light incident on the first predetermined area is distributed throughout the first predetermined area.

[0060] Regarding the first predetermined region R1 and the second predetermined region R2, when the diffusion element 103 is removed from the optical path from the light source 101 to the first predetermined region R1, the light incident on the first predetermined region is substantially concentrated in the second predetermined region R2 located within the first predetermined region R1. For example, the second predetermined region R2 can be a very small area. For example, the second predetermined region R2 can be a point. For example, the ratio of the area of ​​the first predetermined region R1 to the area of ​​the second predetermined region R2 can be 5 to 100, but is not limited to this. Further, for example, the ratio of the area of ​​the first predetermined region R1 to the area of ​​the second predetermined region R2 can be 20 to 200. The larger the ratio of the area of ​​the first predetermined region R1 to the area of ​​the second predetermined region R2, the more power consumption can be reduced while maintaining the brightness of the image. Therefore, in Figure 2A In the display device shown, without the diffuser element 103, the light emitted from the light source unit 101 can be precisely reflected to the second predetermined region R2. Without the diffuser element 103, the light emitted from the light source unit passes through the converging element, the liquid crystal display panel, and the reflective element before reaching the plane containing the second predetermined region. Most of the light, except for stray light, is concentrated in the second predetermined region of this plane, and the light concentrated in the second predetermined region is distributed throughout the second predetermined region. For example, the optical axes of the light beams focused by the converging element are all concentrated in the second predetermined region, and light from other angles (such as stray light) may not concentrate in the second predetermined region.

[0061] The display device provided in the embodiments of this disclosure can expand the second predetermined region R2 into a first predetermined region R1 by providing a diffusion element 103 in the optical path of the light emitted from the light source 101 to the second predetermined region. For example, when the diffusion element 103 has a precise and controllable diffusion function, the first predetermined region R1 is also a region obtained by precisely and controllably expanding the second predetermined region R2, thereby avoiding the light beam from reaching an unwanted position, thereby increasing the brightness of the image and / or reducing the power consumption of the light source.

[0062] and Figure 1 Compared to the HUD shown, the display device provided in the embodiments of this disclosure, with the same field of view (FOV) and the same LED power consumption, has an imaging brightness greater than or equal to 2000 nits. Figure 1The HUD shown has an imaging brightness of less than 2000 nits. For example, the display device provided in the embodiments of this disclosure has an imaging brightness of up to 13000 nits. Brightness can be measured using an imaging brightness meter. Brightness is the brightness of the image seen within the eye box region EB after reflection by the transflective element. For example, the experimental conditions for the above comparison were a FOV of 8.4° × 3.3° and a light source power consumption of 4.6W. 8.4° × 3.3° represents a horizontal FOV of 8.4° and a vertical FOV of 3.3°.

[0063] In the embodiments of this disclosure, a light source unit 101 is provided for a liquid crystal display panel 104. That is, the backlight of a liquid crystal display panel 104 comes from a light source unit 101.

[0064] For example, image source 10 emits image light L10, which, after one or more reflections by reflective element 20, is emitted to transmissive element 30 and reflected thereon. The reflected light is then emitted to a first predetermined region R1. Figure 2A As shown, the image light emitted from the image source 10 is reflected by the reflective element 20 (shown as a freeform mirror in the figure) and then emitted to the transflective element 30. The reflected light obtained by the transflective element 30 can cover the first predetermined area R1 to improve the performance of the display device.

[0065] Without a diffuser, the light emitted from the light source 101 passes through the converging element 102 and the liquid crystal display panel 104, is reflected by the reflecting element 20, and finally reflected by the transflective element 30. The reflected light then converges and falls into the second predetermined area R2. In this case, although the light is used efficiently, the image can only be observed within this very small area, the second predetermined area R2. Therefore, a diffuser 103 is needed. The diffuser 103 can precisely diffuse the light, allowing the diffused light to cover the first predetermined area R1. For example, with the diffuser 103, the light reflected by the transflective element 30 precisely covers the first predetermined area R1, achieving high light efficiency without affecting normal observation. In other words, the combined effect of the converging element 102 focusing the light beam and the diffuser 103 diffusing the light beam allows the light to be distributed in a predetermined area (which could be the eyepiece area), thereby improving light utilization and light efficiency.

[0066] like Figure 2A As shown, Figure 2AThe dashed lines represent the original propagation direction of light without the diffusion element. It can be seen that the light converges in the second predetermined area R2. After the diffusion element is installed, the light covers the first predetermined area R1. It can be understood that the diffused beam can be larger than the first predetermined area R1, as long as it completely covers it. For example, after installing the diffusion element 103, the diffused beam exactly covers the first predetermined area R1, at which point the display device has the highest luminous efficiency. For example, in some embodiments, by providing the converging element 102 and the diffusion element 103, most of the light emitted by the light source 101a can reach the first predetermined area R1, thereby improving imaging brightness or reducing the power consumption of the light source.

[0067] Figure 2A In the diagram, the dashed line indicates that when the diffuser element 103 is removed from the optical path from the light source 101 to the first predetermined region R1, the light emitted from the light source 101 is focused into the second predetermined region R2. Figure 2A The example uses a second predetermined region R2 as a point. In other embodiments, the second predetermined region R2 can be a region within the first predetermined region R1 with an area smaller than the first predetermined region R1.

[0068] The display device provided by the embodiments of this disclosure efficiently utilizes the light emitted by the light source, improving image brightness while reducing the power consumption of the light source. The display device provided by the embodiments of this disclosure achieves efficient light utilization and realizes high-brightness imaging with low energy consumption.

[0069] For example, it can be Figure 2A Based on the display device shown, additional optical elements that facilitate imaging are added.

[0070] For example, an observer's (e.g., a driver or passenger) eye can be positioned in a first predetermined region R1 to see a virtual image located on the side of the reflective element away from the first predetermined region R1. For example, the area the observer needs to view the image, i.e., the eyebox region EB, can be preset according to actual needs. Figure 2A (As shown) refers to the planar area where the observer's eyes are located and where they can see the image displayed by the display device. For example, the first predetermined area R1 may include the eye box area. For example, even if the observer's eyes are deviated from the center of the eye box area EB by a certain distance, such as moving a certain distance up and down or left and right, the observer can still see the image displayed by the display device as long as their eyes are still within the eye box area EB.

[0071] For example, if different locations within the eyebox area are used as observation points, such as the center or edge of the eyebox, the observed virtual image positions will also be different, but the differences are small and can be ignored. It can be assumed that when observing an image within the eyebox area, the position of the virtual image is basically fixed, and the position where the light beam is reflected on the transflective structure is also basically fixed.

[0072] The display device provided by some embodiments of this disclosure enables the light emitted from the light source to accurately cover the first predetermined area R1 after a series of propagations. Almost all the light reflected by the transflective element 30 can enter the first predetermined area R1, making efficient use of the light and thus achieving high-brightness imaging with low power consumption.

[0073] like Figure 2A As shown, the light source unit 101 includes a light source 101a and a reflective light guide element 101b. The light source 101a is configured to emit light, and the reflective light guide element 101b is configured to reflect a portion of the light emitted by the light source 101a that is incident on the reflective light guide element 101b so that it is incident on the converging element 102. Light rays emitted by the light source with a certain dispersion angle are emitted to the reflective light guide element, which converges the large-angle light rays emitted by the light source. The converged light rays are emitted to the converging element, which focuses the light rays to a predetermined range. The converged light rays are emitted to a diffuser element, which diffuses the light rays into a beam with a predetermined cross-sectional shape. The diffused light rays are emitted to the liquid crystal display panel and converted into image light. Figure 2A The light emitted by the light source 101a shown has a certain divergence angle. For example... Figure 2A As shown, the portion of light incident on the reflective light guide element 101b is the large-angle light emitted by the light source 101a, while the small-angle light emitted by the light source 101a can be directly incident on the converging element 102. Of course, in other embodiments, the small-angle light emitted by the light source 101a can also be processed by other elements before being incident on the converging element 102.

[0074] In the embodiments of this disclosure, light includes multiple light rays, or in other words, light includes multiple light beams, each light beam including multiple light rays. For example, light can be light emitted by light source 101a or light emitted by light source unit 101, but is not limited thereto.

[0075] Figure 3 This is a schematic diagram of a first predetermined area and a second predetermined area in a display device provided according to an embodiment of the present disclosure. Figure 3 As shown, the area of ​​the second predetermined region R2 is smaller than the area of ​​the first predetermined region R1. Figure 3In the illustrated embodiment, the second predetermined region R2 is used as an example point. Of course, the second predetermined region R2 can also be a region located within the first predetermined region R1, with an area smaller than the first predetermined region R1. For example, the second predetermined region R2 could be the center of the first predetermined region R1, but it is not limited to this.

[0076] For example, such as Figure 2A As shown, the diffuser element 103 is located between the converging element 102 and the liquid crystal display panel 104, but it is not limited thereto. In other embodiments, the position of the diffuser element 103 can be adjusted. For example, in some embodiments, the diffuser element 103 is not located between the converging element 102 and the liquid crystal display panel 104, but is located on the side of the liquid crystal display panel 104 away from the converging element 102. In other embodiments, the diffuser element 103 can be provided both between the converging element 102 and the liquid crystal display panel 104 and on the side of the liquid crystal display panel 104 away from the converging element 102 to better diffuse the light.

[0077] For example, in some embodiments, the converging element 102 is bonded to the diffuser element 103, and the diffuser element 103 is bonded to the liquid crystal display panel 104, but this is not the only embodiment. In other embodiments, the converging element 102, the diffuser element 103, and the liquid crystal display panel 104 may also be an integral structure, formed as a single unit.

[0078] For example, such as Figure 2A As shown, the area where the light emitted by the light source is reflected on the reflective light guide element is only a small part close to the light source. Therefore, in other embodiments, the reflective light guide element can retain only the part near the light source and remove the part far away from the light source.

[0079] The display device provided in the embodiments of this disclosure adjusts the direction of light by using a converging element, a reflecting element, and a transflective element to focus light emitted from a light source with a large divergence angle to a second predetermined area, thereby achieving efficient utilization of light. Furthermore, by setting a diffusion element, the light is diffused to cover a first predetermined area, so that the eyes of an observer, such as a driver, can observe the HUD image over a large range, thereby improving light efficiency and achieving a better user experience.

[0080] In practical applications, the light emitted from the image source is further altered in its propagation direction after being reflected by curved mirrors, plane mirrors, and windshields. In some embodiments of this disclosure, the light direction is controlled multiple times by converging elements, diffusing elements, reflecting elements (mainly curved mirrors), and transmissive elements, ultimately converging the light and causing it to fall into the first predetermined region R1.

[0081] Figure 4 This is a schematic diagram of a converging element in a display device according to an embodiment of this disclosure. Figure 4 As shown, the converging element 102 is used to control the direction of the light emitted from the light source unit 100, focusing the light to a predetermined range. This can concentrate the light and improve its utilization rate. Figure 4 As shown. The converging element can be a lens or a combination of lenses, such as a convex lens, a Fresnel lens, or a combination of lenses. A lens combination may include a combination of multiple convex lenses, a combination of multiple Fresnel lenses, or a combination of at least one convex lens and at least one Fresnel lens. Figure 4 The following illustration uses a convex lens as an example of a converging element. For instance, when the converging element 102 is a single lens, its focal length is 60mm-200mm. When the converging element 102 uses a combination of lenses, its equivalent focal length is 60mm-200mm. It can be understood that the predetermined range can be a point, such as the focal point of a convex lens, or it can be a small area. The purpose of setting the converging element is to focus the large-angle light emitted from the light source 101, thereby improving light utilization. The converging element 102 can be in the form of a circular, rectangular, or cylindrical lens, but is not limited to these forms. Figure 4 The example described uses one converging element 102 corresponding to one light source unit 101. In other embodiments, one converging element 102 may correspond to multiple light source units 101.

[0082] Figure 5 This is a schematic diagram of a diffusion element in a display device according to an embodiment of the present disclosure. Figure 5 As shown, the diffuser element 103 diffuses a beam of light propagating in the same direction into a beam with a certain distribution angle. The smaller the diffusion angle, the higher the brightness of the beam; the larger the diffusion angle, the lower the brightness of the beam. The diffuser element 103 is used to diffuse the focused light at a certain angle to increase the degree of light diffusion, so that the light can be distributed within a certain area. For example, the diffuser element 103 includes at least one of a diffractive optical element and a scattering optical element.

[0083] For example, the diffuser element 103 can be a low-cost scattering optical element, such as a homogenizer or diffuser. When a light beam passes through a scattering optical element such as a homogenizer, scattering and a small amount of diffraction will occur, but scattering plays a major role, and the light beam will form a large spot after passing through the scattering optical element.

[0084] For example, the diffusion element 103 can also be a diffractive optical element (DOE) with more precise control over the diffusion effect, such as a beam shaper. For instance, a diffractive optical element, by designing microstructures on its surface, diffuses the light beam through diffraction, resulting in a smaller beam with controllable size and shape. After passing through the beam shaper, the light diffuses and forms a beam with a predetermined cross-sectional shape, including but not limited to linear, circular, elliptical, square, or rectangular shapes. By controlling the microstructure of the diffractive optical element, the diffusion angle and cross-sectional shape of the light can be precisely controlled, achieving precise control over the diffusion effect. For example, the predetermined cross-sectional shape of the diffused beam directed towards the first predetermined region R1 after passing through the diffusion element 103 corresponds to the shape of the first predetermined region R1. For example, the diffractive optical element splits a single beam into a two-dimensional array beam with a predetermined intensity distribution. Those skilled in the art can design corresponding microstructures based on the desired predetermined cross-sectional shape of the beam; therefore, the specific structure of the microstructure is not described in detail in the embodiments of this disclosure.

[0085] Figure 6 This is a schematic diagram illustrating the diffusion of a light beam through a diffusion element in a display device according to an embodiment of this disclosure. The light beam L11 diffuses into a rectangular beam L12 after passing through the diffusion element 103. That is, the light diffuses at a specific diffusion angle after passing through the diffusion element, and this diffusion angle is precisely controllable. Figure 6 As shown, the optical axis of the diffused beam L12 is on the same straight line as the optical axis of the beam L11 incident on the diffuser element 103. That is, the optical axis of the beam passing through the diffuser element 103 remains unchanged, and the edge rays of the diffused beam L12 diffuse out at a certain angle along its optical axis.

[0086] For example, such as Figure 6 As shown, the diffusion angle β1 of the diffusion element 103 in the first direction D1 ranges from 5° to 20°, but is not limited to this. The first direction D1 is a direction parallel to the diffusion element 103. The diffusion angle β1 of the diffusion element 103 in the first direction D1 refers to the angle between the two maximum line-of-sight axes of the diffusion element 103 in the first direction D1. The diffusion angle β1 of the diffusion element 103 in the first direction D1 can also adopt other numerical ranges as needed.

[0087] For example, such as Figure 6As shown, the diffusion angle β2 of the diffusion element 103 in the second direction D2 ranges from 5° to 10°, but is not limited to this. The second direction D2 is parallel to the diffusion element 103 and perpendicular to the first direction D1. The diffusion angle β2 of the diffusion element 103 in the second direction D2 is the angle between the two maximum line-of-sight axes of the diffusion element 103 in the second direction D2. The diffusion angle β2 of the diffusion element 103 in the second direction D2 can also adopt other numerical ranges as needed.

[0088] For example, if the diffusion element 103 has a plate-like appearance, the direction parallel to the diffusion element 103 refers to the direction parallel to the plate surface of the diffusion element 103. If the diffusion element 103 comprises multiple microstructures, the direction parallel to the diffusion element 103 refers to the direction parallel to the flat plate surface of the diffusion element 103.

[0089] For example, the first direction D1 is perpendicular to the arrangement direction of the converging element 102, the diffuser element 103, and the liquid crystal display panel 104, and the second direction D2 is perpendicular to the arrangement direction of the converging element 102, the diffuser element 103, and the liquid crystal display panel 104. (Reference) Figure 2A and Figure 6 The alignment direction D0 of the converging element 102, the diffuser element 103, and the liquid crystal display panel 104 is perpendicular to the first direction D1 and the second direction D2. Direction D0 is perpendicular to the light-transmitting surface of the diffuser element 103. Figure 6 Taking the example of beam L11 being incident perpendicularly on diffuser element 103, the incident angle of the beam can also be other. Figure 2A The first direction D1 is perpendicular to the plane of the paper. For example, the first direction D1 is horizontal and the second direction D2 is vertical, but it is not limited to this.

[0090] For example, the light spot formed after beam L11 passes through diffuser 103 can be rectangular. The first direction is the extension direction of the long side of the rectangle, and the second direction is the extension direction of the short side of the rectangle. The diffusion angle in the first direction refers to the angle β1 between the light rays connecting the two ends of the long side of the rectangular light spot, and the diffusion angle in the second direction refers to the angle β2 between the light rays connecting the two ends of the short side of the rectangular light spot. For example, when the light spot formed after beam L11 passes through diffuser 103 is a circular light spot, the diffusion angle is the angle between the light ray at the edge of the light spot and the optical axis, and the diffusion angle is the same in all directions.

[0091] For example, after passing through the diffuser element 103, the light beam L11 will diffuse into a light spot with a predetermined size and shape and a uniform energy distribution. The size and shape of the light spot can be precisely controlled by the microstructure designed on the surface of the diffuser element 103. The predetermined shape may include, but is not limited to, linear, circular, elliptical, square, and rectangular shapes.

[0092] For example, for the diffuser element 103, the propagation angle and spot size of the diffused beam determine the brightness and viewing angle of the final image. The smaller the diffusion angle, the higher the image brightness and the smaller the viewing angle; and vice versa.

[0093] For example, the shape of the eye box area is generally rectangular. Therefore, the rectangular light spot formed by the diffusion element 103 corresponds to the rectangular eye box area, which can improve the light efficiency. When the size of the rectangular light spot is exactly equal to the size of the eye box area and completely covers it, the light efficiency can be further improved.

[0094] Figure 7 This is a schematic diagram of a light source unit in a display device according to an embodiment of the present disclosure. For example, refer to... Figure 2A and Figure 7 The cross-section of the reflective light guide element 101b gradually increases from one end (light inlet b0) to the other end (light outlet b1), and the reflective light guide element 101b has a light outlet b1, such as Figure 7 As shown, in order to improve the utilization rate of light from the light source, most of the light emitted from the light outlet b1 is incident on the converging element 102. For example, approximately 80% or more of the light emitted from the light outlet b1 is incident on the converging element 102, but this is not limited to this. The more light emitted from the light outlet b1 is incident on the converging element 102, the more controllable light there is, and the greater the brightness of the image / virtual image observed within the first predetermined region R1.

[0095] After the light source 101a is reflected from the inner surface of the reflective light guide element 101b, a virtual image of the light source is formed, such as... Figure 7 As shown, the main light rays forming the virtual image (the light rays shown by the dotted lines in the figure) will converge and diffuse again in the light path, with a certain diffusion angle. That is, the presence of a virtual image of the light source (equivalent to a virtual light source array) will cause the light emitted by the light source to diffuse at a diffusion angle θ, relative to the case without the reflective light guide element. In other words, the reflective light guide element 101b plays the role of improving light efficiency and diffusing light, but this diffusion effect cannot be precisely controlled.

[0096] Figure 7 In the image, a1 and a2 represent the virtual images of light source 101a, respectively. Figure 7 The angle θ shown is the diffusion angle of the reflective light guide element 101b. It can be understood that the diffusion process caused by the reflective light guide element reflecting the light source is uncontrollable and the diffusion degree is small. However, the diffusion element in the display device provided in the embodiments of this disclosure diffuses the light precisely and controllably, and the diffusion degree is large. That is, in the embodiments of this disclosure, the light is diffused and ultimately covers the first predetermined area R1 through two diffusion processes.

[0097] Figure 8This is a schematic diagram of a display device having a collimation element according to an embodiment of the present disclosure. For example, such as Figure 8 As shown, the light source unit 101 also includes a collimating element 101c, which is located between the light source 101a and the focusing element 102. The collimating element 101c is configured to adjust a portion of the light emitted by the light source 101a into collimated light. In a display device with a collimating element 101c, the focusing element 102 is easier to control for collimated light.

[0098] For example, such as Figure 8 As shown, the light source 101a is set at the focal position of the collimating element 101c. The light emitted by the light source 101a is divided into two parts. One part of the light (light at a small angle) is directly incident on the collimating element 101 and is collimated into parallel light by the collimating element 101. The other part of the light (light at a large angle) is reflected by the reflective light guide element 101b to the collimating element 101, and after being adjusted by the collimating element 101, it is incident on the converging element 102.

[0099] For example, the collimating element 101c can be a collimating lens or a collimating film. The collimating lens includes one or more of the following: a convex lens, a Fresnel lens, and a lens combination (e.g., a combination of a convex lens and a concave lens, a combination of a Fresnel lens and a concave lens, etc.). For example, the collimating lens can be a convex lens, and the light source 101a can be set at the focal point of the convex lens that serves as the collimating lens 101c. That is, the distance between the convex lens that serves as the collimating lens 101c and the position of the light source 101a is the focal length of the convex lens, so that some of the light rays emitted from the light source 101a in different directions can be emitted in parallel after passing through the collimating element 101c. The collimating lens is set inside the reflective light guide element 101b, and the size of the collimating lens 101c is smaller than the size of the light outlet b1 of the reflective light guide element 101b. It can be set in the cavity inside the reflective light guide element 101b, or it can be set at the light outlet b1 of the reflective light guide element 101b. The collimating film can be a BEF film (Brightness Enhancement Film), which is used to adjust the emission direction of the light to a preset angle range, such as focusing the light within an angle range of ±35° of the collimating film normal.

[0100] For example, the collimating element 101c is located inside the reflective light guide element 101b, and the maximum size of the collimating element 101c is smaller than the size of the light outlet b1 of the reflective light guide element 101b; or, the collimating element 101c is located outside the reflective light guide element 101b, and the maximum size of the collimating element 101c is greater than or equal to the size of the light outlet of the reflective light guide element.

[0101] Figures 9A to 9D This is a schematic diagram of a light source unit in a display device provided for some embodiments of this disclosure. Figures 9A to 9CThis is a perspective view of a light source unit in a display device provided for some embodiments of the present disclosure. Figure 9D This is a plan view of a light source unit in a display device provided for some embodiments of the present disclosure. Figure 9D This is a top view schematic diagram of a light source unit in a display device provided for some embodiments of this disclosure.

[0102] like Figure 9A As shown, a light source 101a is disposed within a reflective light guide element 101b. For example, as Figure 9A As shown, the light source 101a is located at the center of the light inlet b0 of the reflective light guide element 101b, opposite to the light outlet b1. Figure 9B As shown, multiple light sources 101a are located at the light inlet b0, and the multiple light sources 101a are arranged in an array. Figure 9B This explanation uses a two-row, three-column array as an example, but is not limited to this. For example... Figure 9C As shown, multiple light sources 101a are located at the light inlet b0 of the reflective light guide element 101b, and the multiple light sources 101a are arranged linearly. Figure 9C The example given is three light sources 101a located on a straight line, but it is not limited to this.

[0103] For example, there may be one or more light sources 101 in the reflective light guide element 101b. When there is only one light source 101 in the reflective light guide element 101b, the light emitted by a point light source is easier to control and more conducive to improving the utilization rate of light.

[0104] For example, light source 101a is a light-emitting element, including electroluminescent light source, thermal radiation light source, and gas discharge light source. For example, in some embodiments, light source 101a is an electroluminescent light source, which may be a light-emitting diode (LED) light source.

[0105] A reflective light guide element 101b is positioned in the light-emitting direction of the light source 101a. Part of the light emitted from the light source propagates within the reflective light guide element and exits to the converging element. The inner surface of the reflective light guide element has a reflective surface. Large-angle light emitted from the light source is reflected and converged by the reflective surface, improving the utilization rate of the light source. Figure 9B and Figure 9C As shown, when there are multiple light sources, the light sources can be arranged in a matrix or in a linear arrangement at the end of the reflective light guide element. Furthermore, the multiple light sources can be respectively equipped with at least one of red LED, green LED and blue LED.

[0106] For example, the reflective light guide element is a hollow shell with an internal reflective surface. The shell includes a light inlet b0 for housing a light source and a light outlet b1 for emitting light. The shell can be in the shape of a triangular pyramid, a square pyramid, or a parabolic surface. For example, in some embodiments, the shell is in the shape of a square pyramid, such as... Figures 9A to 9C As shown. The cross-section of a square pyramid shape can be rectangular, square, trapezoidal, or parallelogram. Figures 9A to 9D A reflective light guide element with a rectangular cross-section and a pyramidal shape is shown. For example... Figures 9A to 9D As shown, the cross-section of the light outlet b1 and the light inlet b0 of the reflective light guide element 101b are both rectangular. In the embodiments of this disclosure, the shape of the reflective light guide element is not limited to... Figures 9A to 9D As shown.

[0107] Figure 10 This is a schematic diagram of a display device provided for another embodiment of this disclosure. Figure 2A Compared to the display device shown, Figure 10 The illustrated display device shows a light source substrate 101c, with a light source 101a disposed on the light source substrate 101c. To ensure that the direction of light emitted from the liquid crystal display panel 104 naturally points to a first predetermined region R1 (which may include an eye-box region EB), the light source substrate 101c is inclined relative to the liquid crystal display panel 104; that is, the light source substrate 101c and the liquid crystal display panel 104 have a non-zero angle. For example, in some embodiments, the angle A0 between the light source substrate 101c and the liquid crystal display panel 104 is greater than 5° and less than or equal to 30°, but is not limited thereto. Figure 10 In the diagram, the dashed line DL1 represents a plane parallel to the liquid crystal display panel 104. For example, the light source substrate 101c being tilted relative to the liquid crystal display panel 104 means that the light source substrate 101c is tilted relative to the light-emitting surface of the liquid crystal display panel 104. For example, the angle between the light source substrate 101c and the liquid crystal display panel 104 refers to the angle between the light source substrate 101c and the light-emitting surface of the liquid crystal display panel 104. For example, the light-emitting surface of the liquid crystal display panel 104 refers to the surface of the liquid crystal display panel 104 where the displayed image is located.

[0108] For example, such as Figure 10 As shown, the liquid crystal display panel 104 is parallel to the diffuser element 103 and also parallel to the light emission port b1 of the reflective light guide element 101b. Of course, in other embodiments, the liquid crystal display panel 104 may not be parallel to the light emission port b1 of the reflective light guide element 101b. For example, as... Figure 10 As shown, in order to allow more light to reach the first predetermined area R1, the light inlet b0 of the reflective light guide element 101b is tilted relative to the liquid crystal display panel 104.

[0109] Figures 11A to 11D This is a schematic diagram of a light source unit in a display device according to another embodiment of the present disclosure, which can be used as... Figure 10 A schematic diagram of the light source section is shown. Figure 11A , Figure 11B and Figure 11D This is a perspective view of a light source unit in a display device according to an embodiment of the present disclosure. Figure 11B This is a plan view, for example a top view, of a light source unit in a display device according to an embodiment of the present disclosure. Figure 11C This is a side view schematic diagram of a light source unit in a display device provided for some embodiments of this disclosure.

[0110] like Figure 11A , Figure 11B and Figure 11D As shown, in order to match the tilted light source substrate 101c, the light inlet b0 of the reflective light guide element 101b is trapezoidal in shape, and the light outlet b1 of the reflective light guide element 101b is rectangular in shape, with the area of ​​the light outlet b1 being larger than the area of ​​the light inlet b0.

[0111] In the embodiments of this disclosure, the shape of the light-emitting port b1 can match the shape of the liquid crystal display panel 104, that is, the shape of the light-emitting port b1 can be the same as the shape of the liquid crystal display panel 104. For example, in some embodiments, the shape of the light-emitting port b1 and the shape of the liquid crystal display panel 104 are both rectangular, but it is not limited to this. In other embodiments, the shape of the light-emitting port b1 and the shape of the liquid crystal display panel 104 can also be circular, square, or other shapes.

[0112] For example, such as Figure 11C As shown, the light-emitting port b1 of the reflective light guide element 101b is rectangular to match the shape of the rectangular liquid crystal display panel, but is not limited to this. The liquid crystal display panel can also adopt other shapes, and correspondingly, the light-emitting port b1 of the reflective light guide element 101b is also adjusted to the same shape as the liquid crystal display panel.

[0113] like Figure 10 and Figure 11C As shown, the light source 101a is disposed on the side of the light source substrate 101c near the reflective light guide element 101b. In some embodiments of this disclosure, the liquid crystal display panel 104 is parallel to the light outlet b1 of the reflective light guide element 101b. To ensure that the direction of light emitted from the liquid crystal display panel naturally points towards the eye box region, the light source substrate 101c is inclined relative to the light outlet b1 of the reflective light guide element 101b, and the light source substrate 101c and the light outlet b1 of the reflective light guide element 101b have a non-zero angle. For example, in some embodiments, the angle A1 between the light source substrate 101c and the light outlet b1 of the reflective light guide element 101b is greater than 5° and less than or equal to 30°, but is not limited thereto. Figure 11C In the diagram, the dashed line DL2 represents a plane parallel to the light outlet b1 of the reflective light guide element 101b. For example, as... Figure 11C As shown, to accommodate the tilted light source substrate 101c, the light inlet b0 of the reflective light guide element 101b is trapezoidal in shape. This allows light emitted from the liquid crystal display panel to naturally point towards the eye box, and after passing through reflective elements (such as curved mirrors) and transflective elements (such as windshields), as much light as possible is concentrated in the eye box area. Figure 11A , Figure 11B and Figure 11C As shown, the length of the upper base of the trapezoidal light inlet b0 is shorter than the length of the lower base. For example, the trapezoidal light inlet b0 can be an isosceles trapezoid, but it is not limited to this.

[0114] For example, such as Figures 11A to 11C As shown, the reflective light guide element 101b includes a first surface S1 and a second surface S2, which are arranged opposite to each other. The angle A2 between the first surface S1 and the light outlet b1 of the reflective light guide element 101b is less than 90°, and the angle A3 between the second surface S2 and the light outlet b1 of the reflective light guide element 101b is less than 90°. Figures 11A to 11C As shown, the angle A2 between the first surface S1 of the reflective light guide element 101b and the light outlet b1 of the reflective light guide element 101b is greater than the angle A3 between the second surface S2 of the reflective light guide element 101b and the light outlet b1 of the reflective light guide element 101b. Figure 11A and Figure 11B A third surface S3 and a fourth surface S4 are also shown. The third surface S3 and the fourth surface S4 are arranged opposite to each other, with the third surface S3 connecting the sides of the first surface S1 and the second surface S2 on the same side, and the fourth surface S4 connecting the sides of the first surface S1 and the second surface S2 on the other side. For example, the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4 may all be inner surfaces and together constitute the inner surface of the reflective light guide element 101b, but this is not a limitation. In other embodiments, the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4 may all be outer surfaces and together constitute the outer surface of the reflective light guide element 101b.

[0115] For example, refer to Figure 10 and Figure 11C The angle A2 between the first surface S1 of the reflective light guide element 101b and the liquid crystal display panel 104 is less than 90°, and the angle A3 between the second surface S2 of the reflective light guide element 101b and the liquid crystal display panel 104 is less than 90°. For example... Figures 11A to 11CAs shown, the angle A2 between the first surface S1 of the reflective light guide element 101b and the liquid crystal display panel 104 is greater than the angle A3 between the second surface S2 of the reflective light guide element 101b and the liquid crystal display panel 104. Figure 10 In this example, the light outlet b1 of the reflective light guide element 101b is parallel to the liquid crystal display panel 104.

[0116] For example, such as Figure 11C As shown, in order to match the tilted light source substrate 101c, the light inlet b0 of the reflective light guide element 101b is not parallel to the light outlet b1 of the reflective light guide element 101b. That is, the plane where the light inlet b0 of the reflective light guide element 101b is located is not parallel to the plane where the light outlet b1 of the reflective light guide element 101b is located.

[0117] For example, such as Figure 11C As shown, the light source substrate 101c is parallel to the plane containing the light entrance b0. For example, as Figure 11C As shown, the angle A4 between the light source substrate 101c and the first surface S1 of the reflective light guide element 101b is greater than 90°, and the angle A5 between the light source substrate 101c and the second surface S2 of the reflective light guide element 101b is greater than 90°.

[0118] and Figure 11A Compared to the light source unit of the display device shown, Figure 11D The light source section of the display device shown includes multiple light sources 101a. The multiple light sources 101a are arranged in an array. Figure 11A Four light sources 101a are shown, but the number of light sources 101a is not limited to this and can be determined as needed.

[0119] Figure 10 , Figures 11A to 11D The reflective light guide element 101b shown is illustrated with the first surface S1 on top and the second surface S2 on the bottom as an example, but it is not limited to this. The reflective light guide element 101b can also be arranged in other ways, as needed. For example, in some embodiments, the first surface S1 is on the bottom and the second surface S2 is on top in the light source section 101.

[0120] For example, such as Figures 11A to 11D As shown, the first surface S1 is the surface including the upper base of the trapezoidal light entrance b0, the second surface S2 is the surface including the lower base of the trapezoidal light entrance b0, and the third surface S3 and the fourth surface S4 are the surfaces including the two sides of the trapezoidal light entrance b0, respectively. The length of the upper base of the trapezoid is less than the length of the lower base of the trapezoid.

[0121] refer to Figure 2A , Figure 6 , Figures 9A to 9D , Figure 10 as well as Figures 11A to 11D In the embodiments of this disclosure, the cross-section of the reflective light guide element 101b in a plane parallel to the arrangement direction D0 and parallel to the second direction D2 can be a symmetrical shape or an asymmetrical shape, depending on the needs. For example, Figures 9A to 9D The cross-section of the reflective light guide element 101b shown is axisymmetric in a plane parallel to the arrangement direction D0 and parallel to the second direction D2. Figures 11A to 11D The cross-section of the reflective light guide element 101b shown is not symmetrical in the plane parallel to the arrangement direction D0 and the second direction D2. In embodiments of this disclosure, the cross-section of the reflective light guide element 101b in the plane parallel to the liquid crystal display panel 104 may or may not be symmetrical, depending on the requirements. For example, Figures 9A to 9D The reflective light guide element 101b shown has an axisymmetric cross-section in a plane parallel to the liquid crystal display panel 104. Figures 11A to 11D The cross-section of the reflective light guide element 101b shown is symmetrical in a plane parallel to the liquid crystal display panel 104. The plane parallel to the liquid crystal display panel 104 refers to the plane parallel to the light-emitting surface of the liquid crystal display panel 104. The plane parallel to the liquid crystal display panel 104 can be a plane parallel to both the first direction D1 and the second direction D2.

[0122] exist Figure 2A and Figure 10 In the diagram, the first direction D1 is perpendicular to the paper. The plane that is parallel to the arrangement direction D0 and parallel to the second direction D2 can be a plane parallel to the paper. The arrangement direction D0, the first direction D1, and the second direction D2 are as described above and will not be repeated here.

[0123] For example, in an embodiment of this disclosure, the angle between a certain element and the light-emitting port b1 of the reflective light guide element 101b refers to the angle between the element and the plane containing the light-emitting port b1 of the reflective light guide element 101b.

[0124] Figure 12 This is a schematic diagram of a liquid crystal display panel in a display device provided in some embodiments of this disclosure. For example... Figure 12 As shown, the liquid crystal display panel 104 includes a liquid crystal cell CL, which includes a first substrate SBS1 and a second substrate SBS2. The first substrate SBS1 and the second substrate SBS2 are disposed opposite to each other, with a liquid crystal layer LCL sandwiched between them. The liquid crystal layer LCL is sealed within the liquid crystal cell CL by a sealant SLT.

[0125] like Figure 12As shown, the liquid crystal display panel 104 also includes a first polarizer POL1 and a second polarizer POL2 disposed on both sides of the liquid crystal cell CL. The first polarizer POL1 is located on the side of the liquid crystal cell CL closer to the light source 101, and the second polarizer is located on the side of the liquid crystal cell CL away from the light source 101.

[0126] refer to Figure 2A and Figure 12 The light source unit 101 is configured to provide backlight BL to the liquid crystal cell CL. The backlight BL is converted into image light L10 after passing through the liquid crystal display panel.

[0127] For example, the transmission axis of the first polarizer and the transmission axis of the second polarizer may be perpendicular to each other, but this is not a limitation. For example, the first polarizer may allow first linearly polarized light to pass through, and the second polarizer may allow second linearly polarized light to pass through, but this is not a limitation. For example, the polarization direction of the first linearly polarized light may be perpendicular to the polarization direction of the second linearly polarized light.

[0128] Figure 13 This is a schematic diagram of a display device provided for some embodiments of this disclosure. Figure 2A Compared to the display device shown, Figure 13 The display device shown also includes a polarization control element 105, which is located between the light source unit 101 and the liquid crystal display panel 104. The transmission axis of the polarization control element 105 is the same as the transmission axis of the first polarizer. This ensures that light that cannot pass through the first polarizer is removed in advance, preventing the liquid crystal display panel from absorbing and generating heat, thus affecting the lifespan of the liquid crystal display panel. Of course, in Figure 2B and Figure 10 In the display device shown, a polarization control element 105 may also be provided between the light source unit 101 and the liquid crystal display panel 104.

[0129] For example, such as Figure 13 As shown, the polarization control element 105 is disposed between the liquid crystal display panel 104 and the diffusion element 103. Of course, the polarization control element 105 can also be disposed at other locations between the light source section 101 and the liquid crystal display panel 104. For example, in some embodiments, the polarization control element 105 may be located between the converging element 102 and the diffusion element 103. For example, in some embodiments, the polarization control element 105 may be located between the reflective light guide element 101b and the converging element 102.

[0130] For example, the first polarizer POL1 can transmit first linearly polarized light, and the second polarizer POL2 can transmit second linearly polarized light. Therefore, the polarization control element 105 can transmit the first linearly polarized light and reflect / absorb the second linearly polarized light. The first linearly polarized light is the light that the liquid crystal display panel can directly utilize. Because the liquid crystal display panel can only utilize light with a predetermined polarization state, and the light emitted by a general light source is unpolarized, approximately 50% of the light can be utilized by the liquid crystal display panel, while the other 50% is absorbed by the liquid crystal display panel and generates heat, affecting its lifespan.

[0131] Therefore, by adding a polarization control element before the liquid crystal display panel, polarized light that cannot be utilized by the liquid crystal layer (i.e., second-polarized light) will be reflected / absorbed, preventing the liquid crystal layer from overheating and extending its lifespan. For example, the polarization control element is a polarizing reflective film, which can be DBEF (3M trade name), BEF (3M trade name), or a photonic crystal with selective transmittance for polarization and incident angle.

[0132] Embodiments of this disclosure also provide a motor vehicle including any of the aforementioned display devices. The motor vehicle provided in this disclosure, employing any of the aforementioned display devices, allows the driver to directly view richer information, such as navigation maps and complex safety information, without having to look down at the instrument panel while driving. Furthermore, because the display device incorporates a converging element 102 and a diffusing element 103, it features low power consumption, and the display in the first predetermined area R1 has high brightness. Therefore, it can better meet the driver's needs for controlling various information while the vehicle is in motion.

[0133] Where there is no conflict, features of the same embodiment and different embodiments of this disclosure may be combined with each other.

[0134] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

[0135] For all purposes, this patent application claims priority to Chinese Patent Application No. 201910412245.8, filed on May 17, 2019, the disclosure of which is incorporated herein by reference in its entirety as part of embodiments of this disclosure.

Claims

1. A display device, comprising a light source, a converging element, a diffusing element, a liquid crystal display panel, and a reflective element; wherein, The light source is configured to emit light, and the light emitted from the light source passes through the converging element, the diffuser element, the liquid crystal display panel, and the reflective element before reaching the first predetermined area; The converging element is configured to converge light passing through it; The diffusion element is configured to diffuse the light beam passing through the diffusion element without changing the optical axis of the light beam; The liquid crystal display panel is configured to convert the light it receives into image light for emission; The reflective element is configured to reflect the image light and converge the image light; The converging element is configured to focus the optical axis of the light emitted from the light source onto a second predetermined region within the first predetermined region when the diffusion element is removed from the optical path from the light source to the first predetermined region. The area of ​​the second predetermined region is smaller than the area of ​​the first predetermined region, and the first predetermined region corresponds to the observation area of ​​the display device. In this case, when the diffusion element is removed from the optical path from the light source to the first predetermined area, the image light emitted from the liquid crystal display panel is converged.

2. The display device according to claim 1 further includes a transflective element, wherein, Before the image light reaches the first predetermined area, it is reflected by the reflective element, and the reflected light from the reflective element reaches the first predetermined area.

3. The display device according to claim 1, wherein, The diffusion element is located between the converging element and the liquid crystal display panel.

4. The display device according to claim 1, wherein, The diffusion angle of the diffusion element in the first direction ranges from 5° to 20°, and the first direction is a direction parallel to the diffusion element.

5. The display device according to claim 4, wherein, The diffusion angle of the diffusion element in the second direction ranges from 5° to 10°, the second direction is parallel to the diffusion element, and the second direction is perpendicular to the first direction.

6. The display device according to claim 5, wherein, Both the first direction and the second direction are perpendicular to the arrangement direction of the converging element, the diffuser element, and the liquid crystal display panel.

7. The display device according to claim 1, wherein, The light source includes a light source and a reflective light guide element. The light source is configured to emit light, and the reflective light guide element is configured to reflect a portion of the light emitted by the light source that is incident on the reflective light guide element so that it is incident on the converging element.

8. The display device according to claim 7, wherein, The reflective light guide element has a light inlet, and the light source part further includes a light source substrate. The light source substrate is disposed at the light inlet, and the light source is disposed on the light source substrate. The light source substrate is tilted relative to the liquid crystal display panel.

9. The display device according to claim 8, wherein, The angle between the light source substrate and the liquid crystal display panel is greater than 5° and less than or equal to 30°.

10. The display device according to claim 8, wherein, The reflective light guide element has a light outlet, the light inlet and the light outlet are arranged opposite to each other, and the light inlet is inclined relative to the light outlet.

11. The display device according to claim 10, wherein, The area of ​​the light inlet is smaller than the area of ​​the light outlet. The light inlet is trapezoidal in shape, and the light outlet is rectangular in shape.

12. The display device according to claim 11, wherein, The reflective light guide element includes a first surface and a second surface, which are disposed opposite to each other. The angle between the first surface and the liquid crystal display panel is greater than the angle between the second surface and the liquid crystal display panel. The first surface is a surface including the upper base of a trapezoidal light entrance, and the second surface is a surface including the lower base of a trapezoidal light entrance. The length of the upper base of the trapezoid is less than the length of the lower base of the trapezoid.

13. The display device according to claim 7, wherein, The light source unit further includes a collimating element located between the light source and the converging element. The collimating element is configured to adjust the portion of the light emitted by the light source that is incident on the collimating element into collimated light.

14. The display device according to claim 13, wherein, The collimating element is located inside the reflective light guide element, and the maximum size of the collimating element is smaller than the size of the light outlet of the reflective light guide element; or, the collimating element is located outside the reflective light guide element, and the maximum size of the collimating element is greater than or equal to the size of the light outlet of the reflective light guide element.

15. The display device according to any one of claims 1-14, wherein, The converging element includes at least one of a convex lens, a Fresnel lens, and a lens combination.

16. The display device according to any one of claims 1-14, wherein, The diffusion element includes at least one of a diffractive optical element and a scattering optical element.

17. The display device according to any one of claims 1-14, wherein, The liquid crystal display panel includes a liquid crystal cell and a first polarizer and a second polarizer disposed on both sides of the liquid crystal cell. The first polarizer is located on the side of the liquid crystal cell closer to the diffusion element, and the second polarizer is located on the side of the liquid crystal cell farther from the diffusion element.

18. The display device according to claim 17, further comprising a polarization control element, wherein, The polarization control element is located between the light source and the liquid crystal display panel, and the transmission axis direction of the polarization control element is the same as the transmission axis direction of the first polarizer.

19. The display device according to any one of claims 1-14, wherein, The reflective element includes a curved mirror, or a combination of a plane mirror and a curved mirror.

20. The display device according to any one of claims 1-14, wherein, Light with an intensity of more than 60% of the light intensity of the light beam incident on the plane where the first predetermined area is located is concentrated in the first predetermined area; or, light with an intensity of more than 80% of the light intensity of the light beam incident on the plane where the first predetermined area is located is concentrated in the first predetermined area; or, light with an intensity of more than 90% of the light intensity of the light beam incident on the plane where the first predetermined area is located is concentrated in the first predetermined area.

21. The display device according to any one of claims 1-14, wherein, The ratio of the area of ​​the first predetermined area to the area of ​​the second predetermined area is 20 to 200; or, the ratio of the area of ​​the first predetermined area to the area of ​​the second predetermined area is 5 to 100.

22. A head-up display comprising a display device according to any one of claims 1-21.

23. A motor vehicle comprising the head-up display of claim 22.

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