Display device and vehicle

Abstract

The application relates to the technical field of head-up display, in particular to a display device and a vehicle. The display device is successfully constructed by limiting the first angle between the axis of the cylindrical grating 120 and the plane where the main optical axis of the image source 110 is located, and controlling the angle of the first angle in the first preset angle range of [-30 degrees, +30 degrees]. The display device not only has a simple structure and is easy to implement, but also can inhibit stray light through accurate angle control, and significantly improves the display performance and display effect of the display device.

Description

Technical Field

[0001] This application relates to the field of head-up display technology, and more particularly to display devices and vehicles. Background Technology

[0002] 3D display technology can recreate three-dimensional spatial information of a scene, providing a stereoscopic visual experience. It is a core technology in fields such as Virtual Reality (VR), Augmented Reality (AR), naked-eye 3D, and holographic projection, and is widely used in medical imaging, industrial inspection, education and entertainment, and automotive displays. Mainstream technologies include lenticular / cylindrical naked-eye 3D, integrated imaging 3D, light field display, and holographic 3D. Their core principle is to use optical elements to control the direction of light propagation, allowing the left and right eyes to receive images from different perspectives, which are then fused by the brain to form a stereoscopic perception.

[0003] In the context of in-vehicle displays, sunlight may shine through a baffle onto the display device, and then be reflected by the display device to form stray light. This stray light may overlap with the effective imaging light, resulting in a blurred final projected image.

[0004] Therefore, there is an urgent need for a display device that can eliminate stray light, thereby improving the display effect of 3D displays. Summary of the Invention

[0005] This application provides a display device and vehicle to solve the problem in the prior art that stray light may superimpose with effective imaging light, resulting in a blurred image in the final projected image.

[0006] In a first aspect, embodiments of this application provide a display device, the display device including an image source and a lenticular lens grating, the lenticular lens grating being composed of regularly arranged lenticular lens units; The light-incident side of the lenticular lens grating is disposed on the light-outcident side of the image source, and the light-incident surface of the lenticular lens grating faces the image source. The lenticular lens grating is used to refract the light emitted from the image source, so that the light emitted through the lenticular lens grating can enter the preset area after reflection. Wherein, the axis of the cylindrical lens unit along its length extension direction forms a first angle with the plane where the principal optical axis of the image source is located. The first angle is within a first preset angle range [-30 degrees, +30 degrees]. With the plane where the principal optical axis is located as a reference, the angle formed by the axis in the clockwise direction is a negative angle, and the angle formed by the axis in the counterclockwise direction is a positive angle. The plane is determined by the first propagation path of the principal optical axis from the image source to the reflection point and the second propagation path of the reflection point to the preset area.

[0007] In one possible implementation, the first included angle is the angle when the axis is parallel to the plane containing the principal optical axis of the image source.

[0008] In one possible implementation, the axis forms a second angle with a straight line perpendicular to the sub-pixel arrangement direction of the image source, and the second angle is set within a second preset angle range; the second preset angle range is determined by an angle in which the relative width of the moiré fringes generated by the coupling of the lenticular lens grating and the image source is less than 0.3; the relative width is the ratio of the moiré fringe width between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source at the current angle to the moiré fringe width between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source at a reference angle.

[0009] In one possible implementation, the first included angle is an angle that approaches 0 degrees within the range of the first preset included angle, provided that the axis satisfies the second included angle.

[0010] In one possible implementation, the width of each lenticular lens in the lenticular grating is determined based on the second included angle and a preset lenticular lens period.

[0011] In one possible implementation, the display device further includes a light shield disposed above the light-emitting side of the cylindrical lens grating for absorbing stray light reflected from the surface of the cylindrical lens.

[0012] In one possible implementation, the height of the light shield is positively correlated with the absolute value of the first included angle.

[0013] In one possible implementation, the cross-sectional shape of the cylindrical lens unit includes at least one of the following: a convex surface and a concave surface.

[0014] In one possible implementation, the first preset angle range is determined by angles where the normalized value of the reflection angle of the stray light by the cylindrical lens unit is less than 0.4.

[0015] Secondly, embodiments of this application also provide a vehicle including a display device as described in any of the preceding claims. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of the structure of a display device provided in an embodiment of this application; Figure 2 A schematic diagram of the plane containing the main optical axis provided in an embodiment of this application; Figure 3a A top view of the cylindrical lens grating 120 provided in an embodiment of this application; Figure 3b A side view of the cylindrical lens grating 120 provided in an embodiment of this application; Figure 4a A schematic diagram showing the cross-sectional shape of the cylindrical lens provided in the embodiments of this application as a convex surface; Figure 4b A schematic diagram showing the concave cross-sectional shape of the cylindrical mirror provided in the embodiments of this application; Figure 5 A schematic diagram illustrating the relationship between the first included angle obtained through optical simulation and the normalized value of the reflection angle of stray light, provided for embodiments of this application. Figure 6 This is a schematic diagram of diffuse reflection in the XZ section of the cylindrical lens grating 120 provided in an embodiment of this application; Figure 7 A schematic diagram illustrating the use of a light shield to block stray light in an embodiment of this application; Figure 8 The optical path diagram of stray light when the straight line along the extension direction of the cross section of the cylindrical lens grating provided in the embodiments of this application is parallel to the plane containing the principal optical axis; Figure 9a A schematic diagram illustrating a possible image source for an embodiment of this application; Figure 9b A schematic diagram illustrating another possible image source provided for an embodiment of this application; Figure 10 A schematic diagram illustrating the relationship between the relative width of the moiré fringes and the second included angle, obtained through optical simulation, for embodiments of this application; Figure 11 A simplified side view of the optical path of the vehicle-mounted HUD provided in the embodiments of this application; Figure 12 This is a schematic diagram showing the relationship between the width of the cylindrical lens unit and the cylindrical lens period provided in the embodiments of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The applicant discovered that stray light reflected from the display device may superimpose on the effective imaging light, causing black fields to turn gray and white fields to become hazy, resulting in a loss of stereoscopic effect and blurred details in 3D images. Stray light may also disrupt the separation of images between the left and right eyes, causing visual crosstalk and resulting in "ghosting" and double outlines, which are the main causes of 3D motion sickness. Furthermore, stray light may form halos and rainbow spots around strong light, causing loss of edge details in the image. In addition, stray light can easily cause depth information deviation during light field reconstruction, resulting in 3D model deformation and point cloud distortion. Long-term exposure to stray light can easily cause eye fatigue and eye pain. In head-up display (HUD) devices, stray light can disrupt the fusion of virtual and reality and reduce immersion.

[0020] In order to avoid the superposition of stray light and effective imaging light and improve the clarity and integrity of the final image, this application provides a display device and a vehicle.

[0021] In this embodiment, the display device includes a display component and a control component. The display component is configured with preset screen states corresponding to different eye box positions. The control component is used to determine a target screen state corresponding to the current eye box position based on the preset screen states corresponding to different eye box positions and the obtained current eye box position, and to control the display component to switch to the target screen state. Each preset screen state is configured to enable the corresponding eye box position to display a complete virtual image at a set content display distance. The type of the preset screen state is either the position state of the display component or the display area state of the display component.

[0022] Example 1: Figure 1 This is a schematic diagram of the structure of a display device provided in an embodiment of this application. The display device includes an image source 110 and a lenticular lens grating 120, wherein the lenticular lens grating 120 is composed of regularly arranged lenticular lens units 121. The light-incident side of the lenticular lens grating 120 is disposed on the light-outcident side of the image source 110, and the light-incident surface of the lenticular lens grating 120 faces the image source 110. The lenticular lens grating 120 is used to refract the light emitted from the image source 110, so that the light emitted from the lenticular lens grating 120 can enter the preset area after reflection. Wherein, the axis of the cylindrical lens unit 121 along the length extension direction forms a first angle with the plane where the principal optical axis of the image source 110 is located. The first angle is within a first preset angle range [-30 degrees, +30 degrees]. With the plane where the principal optical axis is located as a reference, the angle formed by the axis in the clockwise direction is a negative angle, and the angle formed by the axis in the counterclockwise direction is a positive angle. The plane is determined by the first propagation path of the principal optical axis from the image source 110 to the reflection point and the second propagation path of the reflection point to the preset area.

[0023] In one possible implementation, the cross-sectional shape of the cylindrical mirror includes at least one of the following: a convex surface and a concave surface.

[0024] In this embodiment, the display device includes an image source 110 and a lenticular lens grating 120. The image source 110 serves as the light-emitting reference for the display device, generating initial image light. The image source 110 can be a Liquid Crystal Display (LCD) panel, an Organic Light-Emitting Diode (OLED) screen, or a microdisplay chip, etc. The lenticular lens grating 120 consists of a series of regularly arranged lenticular lens units 121, which form a periodic optical interface at the microscopic level. Each lenticular lens unit 121 has a specific radius of curvature and cross-sectional shape, collectively constituting an optical lens array capable of refraction modulating incident light, i.e., the lenticular lens grating 120. The lenticular lens grating 120 is disposed on the light-emitting side of the image source 110, with its light-incident surface directly facing the image source 110, so that the light emitted from the image source 110 first passes through the lenticular lens grating 120 and undergoes refraction.

[0025] Furthermore, in this embodiment, the cylindrical lens unit 121 has a spatial angle, namely the first angle, between its axis along its length and the plane containing the principal optical axis of the image source 110. The principal optical axis refers to the reference ray pointing from the center point of the image source 110 to the observer or the center of the target imaging area. The plane containing the principal optical axis of the image source 110 is a spatial reference plane determined by the first propagation path from the principal optical axis from the image source 110 to the reflection point and the second propagation path from the reflection point to the preset area. For example, Figure 2 This is a schematic diagram of the plane containing the principal optical axis provided in the embodiments of this application, as shown below. Figure 2 As shown, the plane containing the principal optical axis is a spatial reference plane determined by the first propagation path from the image source to the reflection point and the second propagation path from the reflection point to the preset area. The preset area is the observation area where the human eye or sensor is located, and the reflection point is any point on a surface capable of reflecting light, such as a point on a windshield.

[0026] In this embodiment, the first included angle is strictly limited to a first preset included angle range [-30 degrees, +30 degrees]. This first preset included angle range is not arbitrarily set, but is an optimal solution range derived from a large amount of optical simulation and experimental data. When external light is incident on the surface of the cylindrical lens, it will be reflected and form reflected stray light. When the first included angle is 0 degrees, the axis of the cylindrical lens unit 121 is parallel to the plane where the principal optical axis is located. At this time, under the viewing angle perpendicular to the plane where the principal optical axis is located, the direction of the reflected light is relatively fixed and the divergence angle is also small. At this time, the stray light can be completely eliminated by means of a light shield or the like. However, this embodiment allows the angle of the first included angle to be adjusted between ±30 degrees, so that the cylindrical lens unit 121 can rotate clockwise or counterclockwise relative to the reference plane, thereby avoiding moiré fringes caused by the edge of the cylindrical lens unit 121 being parallel to the straight line perpendicular to the sub-pixel arrangement direction of the image source 110. In the coordinate system definition of this application embodiment, with the plane containing the principal optical axis as a reference, the angle formed by the axis in the clockwise direction is defined as a negative angle, and the angle formed in the counterclockwise direction is defined as a positive angle. This first preset angle range provides great freedom for optical design, allowing designers to flexibly optimize parameters according to the specific image source 110 size, light emission angle, and required target field of view.

[0027] It should be noted that, in the embodiments of this application, the first preset included angle range is determined based on the reflection angle of stray light.

[0028] Figure 3a This is a top view of the cylindrical lens grating 120 provided in an embodiment of this application. Figure 3a As shown, assuming the top view of the lenticular lens grating 120 is the XY plane, each lenticular lens element 121 in the lenticular lens grating 120 presents a rectangle in the XY plane, wherein... Figure 3a The Y direction in the figure is the axis of the cylindrical lens unit 121 along the length extension direction. Figure 3b This is a side view schematic diagram of the cylindrical lens grating 120 provided in an embodiment of this application. Figure 3b As shown, assuming the side view of the lenticular lens grating 120 is the XZ plane, the surface shape of the lenticular lens grating 120 can be understood as a combination curve composed of multiple arcs or approximately arcs in the XZ plane, stretched parallel to the Y axis in the Y direction.

[0029] The cylindrical lens unit extends along its length as described above. Figure 3a and Figure 3b in the Y direction.

[0030] It should be noted that, in the embodiments of this application, the cross-sectional shape of the cylindrical lens is either convex or concave. For example, Figure 4aA schematic diagram showing the cross-sectional shape of the cylindrical lens provided in the embodiments of this application as a convex surface; Figure 4b This is a schematic diagram of a cylindrical mirror with a concave cross-sectional shape provided in an embodiment of this application.

[0031] In order to improve the shielding effect on stray light, based on the above embodiments, in this embodiment, the first preset angle range is determined by the angle where the normalized value of the reflection angle of the stray light by the cylindrical lens unit is less than 0.4.

[0032] In this embodiment, the first preset angle range of the first included angle is an optimal solution range derived from a large amount of optical simulation and experimental data. Optionally, a large candidate first preset angle range can be preset, and then the reflection angle of the cylindrical grating for stray light is simulated for each angle within the candidate first preset angle range. Then, the first preset angle range is determined according to the pre-configured allowable stray light reflection angle. The preset candidate angle range can be [+90 degrees, -90 degrees] or other angle ranges, which are not limited here.

[0033] Example, Figure 5 This illustration shows the relationship between the first included angle obtained through optical simulation and the normalized value of the reflection angle of stray light, as provided in the embodiments of this application. The candidate first preset included angle range can be set to [+90 degrees, -90 degrees]. Through optical simulation, each lenticular grating set based on each included angle within this candidate first preset included angle range is simulated, and the same stray light is used to simulate the reflection angle of stray light on each lenticular grating, thus obtaining... Figure 5 The optical simulation results are shown.

[0034] In this embodiment, a corresponding angle range can be selected as the first preset angle range based on the required reflection angle of stray light. Specifically, this embodiment specifies that a normalized value of the stray light reflection angle less than 0.4 will not affect the display effect; therefore, according to... Figure 5 Based on the optical simulation results, the first preset included angle range is set to [-30 degrees, +30 degrees].

[0035] In summary, this embodiment of the application successfully constructed a display device by defining a specific first angle between the axis of the lenticular lens grating 120 and the plane containing the principal optical axis of the image source 110, and controlling this first angle within a first preset angle range of [-30 degrees, +30 degrees]. This display device is not only simple in structure and easy to implement, but also significantly improves its display performance and effect by suppressing stray light through precise angle control.

[0036] Example 2: In order to improve the effect of blocking stray light, based on the above embodiments, in this embodiment of the application, the first included angle is the angle when the axis is parallel to the plane where the main optical axis of the image source 110 is located.

[0037] In the above Figure 3a and Figure 3b As shown in the three-dimensional diagram of the cylindrical lens grating 120, when sunlight shines back onto the cylindrical lens grating 120, the reflection of light on the surface of the cylindrical lens in the XZ section will form a diffuse reflection effect, which will increase the range of angles of the reflected light. The steeper the surface of the cylindrical lens unit 121, the more severe the diffuse reflection effect. However, this phenomenon will not occur in the YZ section because the cross-sectional shape is flat.

[0038] Example, Figure 6 This is a schematic diagram of diffuse reflection within the XZ section of the lenticular lens grating 120 provided in an embodiment of this application. Figure 6 As shown, when sunlight shines back onto the cylindrical lens grating 120, the range of stray light reflected by the cylindrical lens unit 121 of the cylindrical lens grating 120 is significantly increased due to the influence of the incident angle of the light and the steepness of the surface shape of the cylindrical lens unit 121.

[0039] In practical applications, to block stray light, the display device is not perpendicular to the main optical axis, but rather at a certain angle. This way, without the cylindrical lens grating 120, sunlight reflected off the display device can be completely blocked by the light shield. For example, Figure 7 This is a schematic diagram of a light shield for blocking stray light, provided as an embodiment of this application. Figure 7 As shown, the display device is tilted at a certain angle to the main optical axis, and the sunlight flowing back into the display device can be completely blocked by the light shield after being reflected by the display device.

[0040] Based on the above analysis, considering that the cylindrical lens unit 121 has a fixed direction that will produce the above-mentioned diffuse reflection effect, in this embodiment, the axis of the cylindrical lens unit 121 along the length extension direction should be parallel to the plane where the main optical axis is located. In this way, the diffuse reflection effect occurs in the direction perpendicular to the plane where the main light ray is located. At this time, due to the effect of the tilt of the display device, the diffuse reflection light generated by the cylindrical lens unit 121 will still be completely blocked by the light shield, thereby better blocking stray light.

[0041] Otherwise, if the straight line along the cross-section of the cylindrical grating 120 is parallel to the plane containing the principal optical axis, then the diffuse reflection effect occurs when the principal optical axis is in the plane, and some light rays will inevitably hit the windshield and be reflected into the human eye. For example... Figure 8 The stray light path diagram of the cylindrical lens grating provided in this application embodiment when the straight line along the cross-sectional extension direction is parallel to the plane containing the principal optical axis is as follows. Figure 8 As shown, the diffuse reflection effect occurs when the principal optical axis is in the plane, meaning some light rays can hit the windshield and then be reflected into the human eye. The cross-sectional direction of the cylindrical grating is... Figure 3a and Figure 3b The X direction in the equation.

[0042] As can be seen from the above analysis, the smaller the angle between the axis of the cylindrical lens unit 121 of the cylindrical lens grating 120 along its length extension direction and the plane containing the principal optical axis of the image source 110, the better the stray light blocking effect. Based on this, in order to better block stray light, in this embodiment of the application, the axis of the cylindrical lens unit 121 of the cylindrical lens grating 120 along its length extension direction can be parallel to the plane containing the principal optical axis of the image source 110. This arrangement can block stray light to the greatest extent.

[0043] Example 3: To avoid moiré fringes, based on the above embodiments, in this embodiment, the axis forms a second angle with a straight line perpendicular to the sub-pixel arrangement direction of the image source 110, and the second angle is set within a second preset angle range; the second preset angle range is determined by the angle where the relative width of the moiré fringes generated by the coupling between the cylindrical lens grating 120 and the image source 110 is less than 0.3; the relative width is the ratio of the moiré fringe width between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110 at the current angle to the moiré fringe width between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110 at a reference angle.

[0044] In practical applications, moiré fringes are easily generated during the coupling process between the image source 110 and the lenticular lens grating 120. Specifically, in an optical superposition system, when two objects with periodic structures are parallel in space, such as the edge of the lenticular lens unit 121 in this embodiment and a straight line perpendicular to the sub-pixel arrangement direction of the image source 110, a new type of low-frequency interference fringe, namely moiré fringes, will be generated. Moiré fringes appear as large-area wavy or cloud-like patches on the displayed image, which can severely degrade the image's detail and clarity.

[0045] Based on this, in order to suppress moiré patterns, this application embodiment proposes to configure the relationship between the cylindrical lens unit 121 and the image source 110 such that the axis of the cylindrical lens unit 121 along the length extension direction forms a second angle with a straight line perpendicular to the sub-pixel arrangement direction of the image source 110. The existence of this second angle avoids the edge of the cylindrical lens unit 121 from being parallel to the straight line perpendicular to the sub-pixel arrangement direction of the image source 110, thereby suppressing moiré patterns and improving the display effect.

[0046] The image source comprises multiple pixels, and each pixel further comprises multiple sub-pixels, such as sub-pixels R, G, and B. The sub-pixels in each pixel are arranged in the same direction; the sub-pixel arrangement direction in the above embodiment is the same as the arrangement direction of multiple sub-pixels in a single pixel.

[0047] Furthermore, in this embodiment, if the subpixel arrangement direction is considered as a row, the image source includes at least one row of pixels and at least one column of pixels. The subpixel arrangement direction of all pixels in the image source is consistent, and the subpixel arrangement order of each pixel in the same row is consistent; the subpixel arrangement order of each pixel in different rows may be consistent or inconsistent.

[0048] Example, Figure 9a This is a schematic diagram of a possible image source provided in an embodiment of this application, as shown below. Figure 9a As shown, each pixel of the image source includes sub-pixel R, sub-pixel G, and sub-pixel B. The sub-pixel arrangement order of all pixels in the image source is the same, which is sub-pixel R-sub-pixel G-sub-pixel B. The direction corresponding to this sub-pixel arrangement order is the sub-pixel arrangement direction of this embodiment.

[0049] Figure 9b A schematic diagram of another possible image source provided for an embodiment of this application, as shown below. Figure 9b As shown, each pixel of the image source includes sub-pixel R, sub-pixel G, and sub-pixel B. The sub-pixel arrangement order of each pixel in different rows of the image source is different. The sub-pixel arrangement order of any row is any one of sub-pixel R-sub-pixel G-sub-pixel B, sub-pixel B-sub-pixel R-sub-pixel G, and sub-pixel G-sub-pixel B-sub-pixel R.

[0050] In this embodiment of the application, the second angle between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110 is set within a second preset angle range. The second preset angle range is determined based on the condition that the relative width of the moiré fringes generated by the coupling between the cylindrical lens grating 120 and the image source 110 is less than 0.3, provided that the first angle is within the first preset angle range.

[0051] The relative width of the moiré fringe is the ratio of the width of the moiré fringe at the current angle between the axis of the grating unit along its length extension direction and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110, to the width of the moiré fringe at a reference angle between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110. This reference angle is a pre-designed initial state, such as 0 degrees. In determining the second angle, the moiré fringe width measured at the reference angle can be used as the denominator. During actual debugging, when the second angle is changed, the numerator becomes the moiré fringe width at the current angle. This ratio is calculated and used as the relative width of the moiré fringe to characterize the suppression effect of the current angle setting on the moiré fringes.

[0052] In the specific implementation process, the first included angle and the second included angle have a common side, namely the axis of the cylindrical lens unit 121. Based on this, given the known first preset included angle range of the first included angle, the position of the axis can be adjusted accordingly based on the first preset included angle range. When the axis satisfies the first preset included angle range, the included angle range between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110 is determined, and this included angle range is used as the candidate second preset included angle range of the second included angle.

[0053] For example, if a straight line perpendicular to the sub-pixel arrangement direction of image source 110 is parallel to the plane containing the main optical axis, then the candidate second preset angle range is consistent with the first preset angle range.

[0054] It should be noted that there may be angles in the above-mentioned candidate second preset angle range where the relative width of the generated moiré fringes is greater than or equal to 0.3. Therefore, it is necessary to further filter the candidate second preset angle range based on the relative width of the moiré fringes to obtain the second preset angle range. Each angle in the second preset angle range satisfies that the relative width of the generated moiré fringes is less than or equal to 0.3.

[0055] For example, image source 110 can be driven to display a specific test pattern, such as a full white field or a grayscale image of a specific frequency, so that the optical inspection device can capture an image of the moiré fringes. Using a high-resolution imaging colorimeter, the system can accurately measure the width of the moiré fringes in the current field of view, and then calculate the relative width by dividing the width of the moiré fringes at that angle by the width of the moiré fringes at a reference angle.

[0056] Specifically, based on the candidate second preset angle range, the position of the axis can be adjusted sequentially. The second angle formed by the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110 can be adjusted, and a characteristic curve of relative width versus the second angle can be plotted. This characteristic curve typically contains several minimum and maximum points, where the minimum points correspond to the thinnest relative width of the moiré fringes, and the maximum points correspond to the thickest relative width of the moiré fringes. A second preset angle range with a relative width less than 0.3 can be selected from this characteristic curve.

[0057] Example, Figure 10 This is a schematic diagram illustrating the relationship between the relative width of the moiré fringes and the second included angle obtained through optical simulation, as provided in the embodiments of this application. Figure 10 As shown, if the candidate second preset angle range is [-45 degrees, +45 degrees], then the relative width of the moiré fringes generated by each angle within this candidate second preset angle range is as follows: Figure 10 As shown, it can be based on this Figure 10 The relationship between the relative width of the moiré fringes and the second included angle is shown, and the range of the second preset included angle is determined as [-45 degrees, -42.5 degrees]∪[-37.5 degrees, -32 degrees]∪[-27 degrees, -25 degrees]∪[-21 degrees, -9 degrees]∪[-5 degrees, -2.5 degrees]∪[+2.5 degrees, +5 degrees]∪[+9 degrees, +21 degrees]∪[+25 degrees, +27 degrees]∪[+32 degrees, +37.5 degrees]∪[+42.5 degrees, +45 degrees].

[0058] In this embodiment of the application, the moiré fringes generated are considered acceptable as long as the second angle formed by the axis of the grating unit along the length extension direction and the straight line perpendicular to the sub-pixel arrangement direction of the image source 110 is within the range of the second preset angle.

[0059] To further eliminate the influence of stray light, based on the above embodiments, in this embodiment, the first included angle is an angle that approaches 0 degrees within the range of the first preset included angle, provided that the axis satisfies the second included angle.

[0060] In actual large-scale industrial production and precision optical assembly, simply pursuing the theoretical minimum moiré fringe width often leads to extremely high manufacturing difficulties and costs. This is because the target angle for minimizing the moiré fringe width is often an extremely narrow singularity, which is highly sensitive to assembly errors.

[0061] To resolve this technical contradiction, this application proposes a preferred principle that approaches 0 degrees. Specifically, in this application embodiment, the first included angle is configured to select the angle that is numerically closest to 0 degrees, provided that the second included angle is within a second preset included angle range.

[0062] The fact that the first included angle is close to 0 degrees means that the extension direction of the cylindrical grating 120 is as parallel or nearly parallel as possible to the principal optical axis plane of the image source 110 on a macroscopic scale. If the first included angle is too large, it will result in a larger reflection angle of stray light, increasing the design difficulty of peripheral structures such as the light shield.

[0063] The specific implementation steps of this application embodiment are as follows: by optical simulation or experimental measurement, the angle of the first angle corresponding to each second angle within the second preset angle range is determined, and then based on the angle of each first angle, an angle close to 0 degrees is selected as the final set value of the first angle.

[0064] In one possible implementation, based on the above embodiments, in this application embodiment, the width of each cylindrical lens unit 121 in the cylindrical lens grating 120 is determined based on the second included angle and a preset cylindrical lens period.

[0065] To ensure the lenticular lens effect, in this embodiment, regardless of how the first and second included angles are set, the lenticular lens period of the lenticular lens unit 121 along the screen edge direction remains unchanged. However, the presence of the first and second included angles causes a change in the width of the lenticular lens unit 121.

[0066] Therefore, in this embodiment of the application, before determining the first included angle and the second included angle, it is necessary to first determine the period, surface shape, etc. of the cylindrical lens grating. Figure 11 This is a simplified side view of the optical path of an in-vehicle HUD provided in an embodiment of this application. Figure 11 As shown, the lenticular lens grating is attached to the surface of the display screen. Each lenticular lens period of the lenticular lens grating covers a certain number of screen sub-pixels. The lenticular lens period is determined by the sub-pixel period and the number of sub-pixels covered. Its size is generally between 0.05 and 0.3 mm. The larger the sub-pixel period and the more sub-pixels covered, the larger the period is generally. The shape of the lenticular lens needs to ensure that the light emitted from the screen pixel can be focused and imaged at the human eye. Its shape can be an arc or an aspherical surface. The corresponding sag is positively correlated with the period and is generally between 4 and 30 μm.

[0067] Example, Figure 12 This is a schematic diagram showing the relationship between the width and period of the cylindrical lens unit provided in the embodiments of this application. Figure 12 As shown, the width T' of the cylindrical lens unit 121 and the cylindrical lens period T satisfy the following formula:

[0068] Where T' represents the width of the cylindrical lens unit 121, and T represents the cylindrical lens period. This indicates the second included angle.

[0069] Example 4: In order to reduce the influence of stray light, based on the above embodiments, in this embodiment of the application, the display device further includes a light shield, which is disposed above the light-emitting side of the cylindrical lens grating 120 and is used to absorb stray light reflected by the surface of the cylindrical lens.

[0070] In practical applications, when the axis of the lenticular lens grating 120 is set at a first angle to the plane containing the principal optical axis of the image source 110, the stray light generated by sunlight shining on the surface of the lenticular lens grating 120 and being reflected by the lenticular lens grating 120 will not enter the preset observation area, but will instead be directed towards the frame, inner wall of the casing, or other non-display areas of the display device. After multiple diffuse reflections inside the device, this light will form a uniform background light screen, superimposed on the normal display image. This phenomenon is particularly noticeable when displaying black or dark scenes, causing the black levels of the image to rise, the contrast to drop significantly, and making the image appear hazy and lacking in transparency.

[0071] To solve this technical problem, the embodiments of this application provide a specific light-absorbing structure or light-absorbing texture in the non-optical area of ​​the lenticular lens grating 120, that is, the non-effective area for light emission or the inner wall of the display device housing. In other words, the display device provided in the embodiments of this application also includes a light shield, which is disposed above the light-emitting side of the lenticular lens grating 120 to absorb stray light reflected by the surface of the lenticular lens.

[0072] Specifically, the distribution trajectory of stray light that fails to enter the eye box can be determined using techniques such as ray tracing simulation. This stray light is typically concentrated at the edge of the field of view, and its exit angle is closely related to the deflection angle of the cylindrical grating 120. Based on this, an embodiment of this application incorporates a light shield in the propagation path of the stray light.

[0073] Secondly, the light shield in this application embodiment can be a flat surface coated with black, or it can be a light-trapping design using micro-nano structures. Specifically, micron-scale pyramid arrays or inverted conical holes can be fabricated on the surface of the light shield. When stray light is incident on these microstructures, it will undergo multiple reflections within the structure. According to the principles of geometric optics, each reflection absorbs some energy. After multiple reflections, the energy of the light is almost completely absorbed. This design has a better light absorption effect than traditional black frosted coatings and can effectively prevent light from escaping due to specular reflection.

[0074] Furthermore, since the first included angle determines the deflection direction of the light by the lenticular lens grating 120, the distribution of stray light is also directional. In this embodiment, the distribution density and angle of the light shield can be dynamically adjusted according to the specific value of the first included angle. For example, if the first included angle causes the stray light to be deflected mainly to the left, then the density and thickness of the light-absorbing structure on the left edge will increase accordingly, while the density on the right edge will decrease appropriately. This asymmetrical light-shielding design ensures optimal stray light absorption while maximizing internal space savings, which is beneficial for the thinner and lighter design of the display device.

[0075] Furthermore, this application embodiment also uses a black polymer composite material doped with carbon nanotubes to prepare the light shield. The carbon nanotubes have extremely low reflectivity and extremely high thermal conductivity, which not only absorbs light, but also converts the absorbed light energy into heat energy and dissipates it rapidly, preventing local overheating caused by prolonged high-brightness display, which in turn causes thermal deformation of the cylindrical lens grating 120.

[0076] To further reduce the influence of stray light, based on the above embodiments, in this embodiment, the height of the light shield is positively correlated with the absolute value of the first included angle.

[0077] In the above embodiments, the width of the moiré fringes can be compressed to an acceptable range by adjusting the position of the axis of the lenticular lens grating 120, provided that the first included angle is within the range of the first preset included angle. Furthermore, the smaller the first included angle, the more concentrated the direction of stray light, resulting in a better effect of the light shield in blocking stray light, and the height can be made lower, occupying less space, which is beneficial for the miniaturization of the entire display device. In actual installation, if the first included angle deviates and thus stray light is not completely eliminated, the height and shape of the light shield can be appropriately changed to completely eliminate stray light.

[0078] Specifically, in this embodiment, the height of the light shield is positively correlated with the absolute value of the first included angle. The smaller the first included angle, the lower the height of the light shield; the larger the first included angle, the higher the height of the light shield.

[0079] Example 5: The above description primarily focuses on the display device provided in this application from an equipment perspective. It is understood that the display device can also be deployed in vehicles.

[0080] Based on the same inventive concept as the display device embodiments, this application also provides a vehicle that integrates a display device as described in any of the above embodiments. Related features can be found in the above method embodiments and will not be repeated here. This display device can serve as a core component of a HUD system, installed inside the dashboard or below the windshield.

[0081] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0082] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0083] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0085] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A display device, characterized in that, The display device includes an image source and a lenticular lens grating, wherein the lenticular lens grating is composed of regularly arranged lenticular lens units; The incident light side of the lenticular lens grating is disposed on the emitting light side of the image source, and the incident light surface of the lenticular lens grating faces the image source. The lenticular lens grating is used to refract the light emitted from the image source, so that the light emitted through the lenticular lens grating can enter the preset area after reflection. Wherein, the axis of the cylindrical lens unit along its length extension direction forms a first angle with the plane where the principal optical axis of the image source is located. The first angle is within a first preset angle range [-30 degrees, +30 degrees]. With the plane where the principal optical axis is located as a reference, the angle formed by the axis in the clockwise direction is a negative angle, and the angle formed by the axis in the counterclockwise direction is a positive angle. The plane is determined by the first propagation path of the principal optical axis from the image source to the reflection point and the second propagation path of the reflection point to the preset area.

2. The display device according to claim 1, characterized in that, The first included angle is the angle when the axis is parallel to the plane containing the principal optical axis of the image source.

3. The display device according to claim 1, characterized in that, The axis forms a second angle with a straight line perpendicular to the sub-pixel arrangement direction of the image source, and the second angle is set within a second preset angle range; the second preset angle range is determined by the angle where the relative width of the moiré fringes generated by the coupling of the lenticular lens grating and the image source is less than 0.3; the relative width is the ratio of the moiré fringe width between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source at the current angle to the moiré fringe width between the axis and the straight line perpendicular to the sub-pixel arrangement direction of the image source at a reference angle.

4. The display device according to claim 3, characterized in that, The first included angle is an angle that approaches 0 degrees within the range of the first preset included angle, provided that the axis satisfies the second included angle.

5. The display device according to claim 3, characterized in that, The width of each cylindrical lens in the cylindrical lens grating is determined based on the second included angle and the preset cylindrical lens period.

6. The display device according to claim 1, characterized in that, The display device further includes a light shield, which is disposed above the light-emitting side of the cylindrical lens grating and is used to absorb stray light reflected by the surface of the cylindrical lens.

7. The display device according to claim 6, characterized in that, The height of the light shield is positively correlated with the absolute value of the first included angle.

8. The display device according to claim 1, characterized in that, The cross-sectional shape of the cylindrical lens unit includes at least one of the following: convex and concave.

9. The display device according to claim 1, characterized in that, The first preset angle range is determined by the angle where the normalized value of the reflection angle of the stray light by the cylindrical lens unit is less than 0.

4.

10. A vehicle, characterized in that, Includes the display device as described in any one of claims 1-9.

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