Image generation unit and head-up display device

Abstract

The invention relates to an image generation unit and a head-up display device. In one aspect, there is provided an image generation unit including: a backlight device configured to provide backlight; a first liquid crystal panel disposed on a side of the backlight device providing backlight and configured to display an image; a dimming element disposed between the first liquid crystal panel and the backlight device and configured to adjust a transmittance of the backlight through the dimming element; and a control device configured to control the dimming element according to a display content of an image displayed by the first liquid crystal panel such that only a first region of the dimming element allows the backlight to pass therethrough to irradiate an entire second region of the first liquid crystal panel where the display content is displayed, where the first region corresponds in shape and size to the second region. Therefore, the damage of backlight to the display panel can be reduced, the display panel can bear larger sunlight backward flow energy, and the contrast ratio of a displayed image can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more specifically, to an image generation unit and a head-up display device including the image generation unit. Background Technology

[0002] Head-up display (HUD) devices are widely used in vehicles and other means of transportation. They are used to display vehicle information such as vehicle status on the windshield or composite mirror of the vehicle, so that the driver can obtain this information while maintaining continuous attention to road conditions.

[0003] Due to the light transmittance of the windshield, sunlight can pass through the windshield into the HUD device and travel along the reverse path of the display light to reach and enter the display panel of the Picture Generation Unit (PGU). This phenomenon is commonly referred to as sunlight backflow.

[0004] The PGU display panel of commonly used HUD devices is a single-layer LCD screen. The energy of sunlight shining on one side of the display panel will be absorbed by the display panel, and the energy of backlight shining on the opposite side of the display panel will also be absorbed by the display panel. This will cause the display panel temperature to rise, which may damage the display panel. Summary of the Invention

[0005] This section provides a general overview of this disclosure, rather than a full disclosure of the entire scope or all features of this disclosure.

[0006] One object of this disclosure is to provide a PGU that can reduce the damage of backlight to the display panel.

[0007] Another objective of this disclosure is to provide a PGU that enables a display panel to withstand greater solar backflow energy.

[0008] Another object of this disclosure is to provide a PGU that can improve the contrast of a displayed image.

[0009] To achieve at least one of the above objectives, according to one aspect of this disclosure, a PGU is provided, comprising:

[0010] Backlight device, configured to provide backlight;

[0011] A first liquid crystal panel is arranged on the side of the backlight device that provides backlight and is configured to display an image;

[0012] A dimming element is disposed between the first liquid crystal panel and the backlight device, and configured to adjust the transmittance of the backlight through the dimming element; and

[0013] The control device is configured to control a dimming element according to the display content of the image displayed on the first liquid crystal panel, such that only a first area of ​​the dimming element allows backlight to pass through to illuminate the entire second area of ​​the display content of the first liquid crystal panel, wherein the first area corresponds to the second area in shape and size.

[0014] In some implementations, the dimming element can be a second liquid crystal panel.

[0015] In some implementations, the resolution of the first liquid crystal panel may be higher than that of the second liquid crystal panel.

[0016] In some implementations, each pixel of the first liquid crystal panel may include a red subpixel, a green subpixel, and a blue subpixel, and the second liquid crystal panel may not include color subpixels.

[0017] In some implementations, the second liquid crystal panel may include two or more gray levels.

[0018] In some embodiments, the PGU may also include a diffuser sheet disposed between the first liquid crystal panel and the dimming element.

[0019] In some embodiments, the diffuser may have a structure for deflecting the central principal ray of the diverging beam formed therethrough.

[0020] In some embodiments, the PGU may also include a deflecting optical element disposed on the side of the dimming element near the backlight device to deflect light emitted therefrom.

[0021] In some embodiments, the second liquid crystal panel may include a first polarizing film and a second polarizing film. The first polarizing film is disposed on the side of the second liquid crystal panel near the backlight device, and the second polarizing film is disposed on the side of the second liquid crystal panel near the first liquid crystal panel. Both the first polarizing film and the second polarizing film are reflective polarizing films.

[0022] According to another aspect of this disclosure, a PGU is also provided, comprising:

[0023] Backlight device, configured to provide backlight;

[0024] A first liquid crystal panel is arranged on the side of the backlight device that provides backlight and is configured to display an image;

[0025] A dimming element is disposed between the first liquid crystal panel and the backlight device, and configured to adjust the transmittance of the backlight through the dimming element; and

[0026] The control device is configured to control a dimming element according to the display content of the image displayed on the first liquid crystal panel, such that only a first area of ​​the dimming element allows backlight to pass through to illuminate the entire second area of ​​the display content of the first liquid crystal panel, wherein the first area corresponds to the second area in shape and the first area is larger than the second area.

[0027] In some implementations, the distance by which the first region extends outward relative to the second region is 2 to 24 pixels.

[0028] According to another aspect of this disclosure, a HUD device is also provided, which includes the PGU according to any of the above embodiments.

[0029] According to the above technical solution, by setting an upper liquid crystal display panel and a lower dimming element, and according to the display content of the image displayed on the liquid crystal display panel, the dimming element is configured such that only a first area corresponding to the display content area in terms of shape and size allows backlight to pass through. The backlight provided by the backlight device does not substantially raise the temperature of the liquid crystal display panel, thereby reducing the possibility of thermal damage to the liquid crystal display panel caused by backlight exposure. Moreover, since most of the backlight energy is blocked by the dimming element, in the event of sunlight backflow, the liquid crystal display panel essentially only absorbs the energy of sunlight. Therefore, the liquid crystal display panel can withstand greater energy sunlight backflow without damage. In addition, since very little backlight reaches the background area of ​​the liquid crystal display panel, the brightness of the background of the displayed image is reduced, thereby obtaining an image with higher contrast. Furthermore, since sunlight passing through the display content area of ​​the liquid crystal display panel is partially absorbed by the dimming element, the damage to other components caused by sunlight energy backflow into the PGU can be reduced. Attached Figure Description

[0030] The features and advantages of embodiments of the present disclosure will become more readily understood from the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be enlarged or reduced to show details of specific components.

[0031] In the attached diagram:

[0032] Figure 1 This diagram illustrates how external sunlight flows back into the PGU of a HUD device based on relevant technology.

[0033] Figure 2 This is a schematic diagram of the structure of a PGU according to an embodiment of the present disclosure.

[0034] Figure 3 A schematic diagram of an exemplary pattern displayed on a first liquid crystal panel.

[0035] Figure 4This is a schematic diagram showing that the first region is larger than the second region.

[0036] Figure 5 This is a schematic diagram illustrating the diffusion of light within a certain angular range.

[0037] Figure 6 This is a schematic diagram of the structure of a PGU according to another embodiment of the present disclosure.

[0038] Figure 7 This is a schematic diagram of the structure of a PGU according to yet another embodiment of the present disclosure.

[0039] Figure 8 This is a schematic diagram of the structure of a PGU according to another embodiment of the present disclosure.

[0040] Figure 9 This is a schematic diagram of the structure of a PUG according to yet another embodiment of the present disclosure.

[0041] Figure 10 This is a schematic diagram of the structure of a HUD device according to an embodiment of the present disclosure.

[0042] In the accompanying drawings, the same or corresponding technical features or components are represented by the same or corresponding reference numerals. Detailed Implementation

[0043] The present disclosure will now be described in detail with reference to the accompanying drawings and exemplary embodiments. It should be noted that the following detailed description of the present disclosure is for illustrative purposes only and is not intended to limit the scope of the disclosure.

[0044] It should be noted that, for clarity, not all features of a particular embodiment are described or shown in the specification and drawings. Furthermore, to avoid unnecessary details obscuring the technical solutions of interest in this disclosure, only the device structure closely related to the technical solutions of this disclosure is described and shown in the specification and drawings, while other details that are not closely related to the technical content of this disclosure and are known to those skilled in the art are omitted.

[0045] Reference Figure 1 In related technologies, a HUD device 1' typically includes a PGU 10' (schematically shown with a dashed box), a first reflector 20', and a second reflector 30'. The PGU 10' emits display light S' carrying information such as vehicle status towards the first reflector 20'. The display light S' is reflected by the first reflector 20' to the second reflector 30', then by the second reflector 30' to the windshield 2', and finally by the windshield 2' to the eye box 3'. Thus, on the outer side of the windshield 2' (i.e., ...), Figure 1The image is displayed on the left side of the windshield 2' and a virtual image 4' is formed on the rearward extension line of the reflected display light S', for the driver to observe. It should be noted that the eye box 3' refers to the range of space within which the user's (e.g., the driver) eyes can move while maintaining a clear and complete view of the image.

[0046] As mentioned earlier, due to the light transmittance of the windshield 2', external sunlight 5' will pass through the windshield 2' and enter the HUD device 1', and will essentially follow the reverse path of the emission path of the display light S'. Figure 1 (Shown in dashed line) propagates (also known as backflow) to PGU10'.

[0047] like Figure 1 As shown, PGU10' includes a backlight device 11' and a display panel 12'. The backlight device 11' provides backlight to the display panel 12', which is used to display images. Typically, the display panel 12' is a single-layer LCD display. In the event of backlighting, the outer surface of the display panel 12', i.e., the side away from the backlight device 11', absorbs the energy of the sunlight shining on it, while the inner surface of the display panel 12', i.e., the side closer to the backlight device 11', absorbs the energy of the backlight shining on it. This causes the temperature of the display panel 12' to rise, and may therefore cause thermal damage to the display panel 12'.

[0048] In response, according to embodiments of this disclosure, a PGU for HUD devices is proposed. Hereinafter, reference will be made to... Figure 2 and Figure 3 The PGU10 according to an embodiment of the present disclosure will be described.

[0049] First, refer to Figure 2 The diagram illustrates the schematic internal structure of the PGU10. The PGU10 includes a backlight device 11, a first liquid crystal panel 12, a dimming element 13, and a control device (not shown).

[0050] The backlight device 11 is arranged on the inner side of the first liquid crystal panel 12 with respect to the PGU10, that is, Figure 2 The backlight device 11 is located below the first liquid crystal panel 12 for providing backlight to the first liquid crystal panel 12. Exemplarily, the backlight device 11 may include a circuit board and light-emitting diodes (LEDs) disposed on the circuit board for providing backlight towards the first liquid crystal panel 12 via the LEDs. It is conceivable that the backlight device 11 may also take any other suitable form.

[0051] The first liquid crystal panel 12 is arranged on the side of the backlight device 11 that provides backlight, that is, Figure 2The backlight device 11 is positioned above the central backlight unit 11 and configured to display an image. Specifically, the light provided by the backlight unit 11 passes through the first liquid crystal panel 12 to form display light S carrying information such as vehicle conditions, thereby displaying an image. For example, as Figure 3 As shown, the first liquid crystal panel 12 displays an image 120 when illuminated by backlight. The content of the image 120 includes road information on the upper side indicating the road being traveled, speed information on the lower left side indicating the travel speed, and direction information on the lower right side indicating the road direction.

[0052] A dimming element 13 is disposed between the first liquid crystal panel 12 and the backlight device 11, and the dimming element 13 is configured to adjust the transmittance of the backlight provided by the backlight device 11 through the dimming element 13. For example, some areas of the dimming element 13 may have lower transmittance to the backlight, while some areas may have higher transmittance to the backlight.

[0053] The control device is configured to control the dimming element 13 according to the display content of the image displayed on the first liquid crystal panel 12, such that only a first area of ​​the dimming element 13 allows backlight to pass through to illuminate the entire area of ​​the first liquid crystal panel 12 displaying the display content (hereinafter referred to as the second area), wherein the first area corresponds to the second area in shape and size.

[0054] For example, when the image to be displayed by the first liquid crystal panel 12 is Figure 3 When the image 120 shown is displayed, the control device controls the dimming element 13 so that only the first area of ​​the dimming element 13, which corresponds in shape and size to the second area of ​​the display content of the image 120 on the first liquid crystal panel 12 (i.e., the road information on the upper side, the speed information on the lower left side, and the direction information on the lower right side), allows backlight to pass through so as to illuminate the entire second area, thereby allowing the first liquid crystal panel 12 to display the aforementioned display content. Meanwhile, the other areas of the dimming element 13 do not allow backlight to pass through, that is, the transmittance of the aforementioned other areas of the dimming element 13 to backlight is zero.

[0055] The second area of ​​the display content of the display image 120 on the first liquid crystal panel 12 refers to the area occupied by the display content on the first liquid crystal panel 12. For example, in Figure 3In the diagram, the second region comprises the area occupied by the road sign on the upper side, the area occupied by the speed sign on the lower left side, and the area occupied by the direction sign on the lower right side. The first region of the dimming element 13 is a portion of the backlight-illuminated area of ​​the dimming element 13, and its position is set such that the backlight transmitted through the first region can illuminate the entire second region of the first liquid crystal panel 12. This allows light to pass through the second region, be reflected by subsequent lenses, and finally enter the eye box area, enabling the first liquid crystal panel 12 to display the content and allowing the entire image to be seen in the eye box. For example, the first region can be perpendicular to the surface of the first liquid crystal panel 12 (e.g., the second region is perpendicular to the surface of the first liquid crystal panel 12). Figure 2 The first region (as shown in the vertical direction) is directly opposite the second region, or the first region may be slightly offset relative to the second region, that is, slightly offset, not completely opposite, as long as the backlight transmitted through the first region can illuminate the entire second region. Furthermore, the correspondence between the first region and the second region in shape and size means that the first region and the second region are substantially the same or matched in shape and size; that is, ideally, the first region and the second region are completely identical or matched in shape and size. However, considering possible installation errors, light deflection, etc., the first region and the second region may have slight differences in shape and size. Therefore, the areas of the dimming element 13 illuminated by backlight, excluding the first region, correspond to the areas of the first liquid crystal panel 12 excluding the second region (i.e., the background area corresponding to the background of image 120), and backlight transmission is not allowed; that is, the transmittance of the aforementioned other areas of the dimming element 13 for backlight is zero.

[0056] The image may be transmitted from the host computer or may be user-defined. The control device may be configured to acquire the image through communication with the host computer, and the control device may also control the first liquid crystal panel 12 to display the image and control the dimming element 13 to allow backlight to pass through only a first area based on the acquired image.

[0057] By allowing backlight to pass through only the first area of ​​the dimming element 13, the backlight S1 illuminating other areas of the dimming element 13 cannot pass through the dimming element 13 to illuminate the first liquid crystal panel 12 (for example, the backlight may be absorbed by the aforementioned other areas of the dimming element 13). Therefore, the temperature of the first liquid crystal panel 12 will not rise. Moreover, since most of the area of ​​the image that is usually displayed is an area without display content, the aforementioned other areas of the dimming element 13 occupy most of the entire area of ​​the dimming element 13, so that most of the backlight provided by the backlight device 11 cannot pass through the dimming element 13 to illuminate the first liquid crystal panel 12, and thus will not affect the temperature of the first liquid crystal panel 12.

[0058] The backlight S2 that illuminates the first area of ​​the dimming element 13 can pass through the first area to form the backlight S3 that illuminates the second area of ​​the first liquid crystal panel 12, and can pass through the second area to form the display light S of the display image 120. Since the first area and the second area correspond, the backlight S3 will not illuminate the background area of ​​the first liquid crystal panel 12, so it will not cause the temperature of the first liquid crystal panel 12 to rise significantly. Moreover, since the backlight that passes through the first area of ​​the dimming element 13 is only a small part of the backlight provided by the backlight device 11, even if it illuminates other areas of the first liquid crystal panel 12, it will not have a significant impact on the temperature of the first liquid crystal panel 12.

[0059] Furthermore, sunlight S10 that illuminates the background area of ​​the first liquid crystal panel 12 will be absorbed by the background area of ​​the first liquid crystal panel 12, while sunlight S11 that illuminates the second area of ​​the first liquid crystal panel 12 will pass through the second area and be partially absorbed by the dimming element 13.

[0060] In this way, the backlight provided by the backlight device 11 is essentially not used to raise the temperature of the display panel, i.e., the first liquid crystal panel 12, which displays the image. This reduces the possibility of thermal damage to the first liquid crystal panel 12 due to backlight exposure. Furthermore, since most of the backlight energy is blocked by the dimming element 13 and not absorbed by the first liquid crystal panel 12, in the event of sunlight backflow, the first liquid crystal panel 12 essentially only absorbs the energy of sunlight. Therefore, the first liquid crystal panel 12 can withstand greater sunlight backflow, or in other words, can withstand a greater temperature rise without damage. In addition, since very little backlight reaches the background area of ​​the first liquid crystal panel 12, the brightness of the background of the displayed image is lower, resulting in an image with higher contrast. Moreover, since the sunlight S11 passing through the second area of ​​the first liquid crystal panel 12 is partially absorbed by the dimming element 13, the damage to other components, such as the LEDs of the backlight device 11, caused by sunlight backflow into the PGU10 can be reduced.

[0061] In some implementations, where the first region corresponds in shape to the second region, the first region may be larger than the second region.

[0062] Specifically, such as Figure 4As shown, the first region Q1 can be obtained by slightly enlarging the second region Q2, that is, the first region is slightly larger than the second region, so that a certain illumination redundancy can be formed when the backlight transmitted through the first region illuminates the second region. Installation errors, range expansion caused by the compensation diffusion angle, distortion, and deflection angle may cause pixel misalignment, resulting in the second region of the first liquid crystal panel 12 not being fully illuminated, and thus the display light emitted from the first liquid crystal panel 12 cannot be observed within the entire eye box. By obtaining the aforementioned illumination redundancy, the display light emitted from the first liquid crystal panel 12 can be observed within the entire eye box, thereby achieving a good visual experience.

[0063] For example, the distance by which the first region extends outward relative to the second region can be from 2 pixels to 24 pixels.

[0064] like Figure 4 As shown, W indicates the distance by which the first region Q1 extends outward relative to the second region Q2. When this distance W is less than 2 pixels, it may not be able to effectively compensate for pixel misalignment, causing some areas of the displayed image to become dark; while when this distance W is greater than 24 pixels, although it can effectively compensate for pixel misalignment, it will waste too much energy and may affect the temperature rise of the first liquid crystal panel 12 and the contrast of the image due to excessive illumination of dark areas near the displayed content.

[0065] In some embodiments, the dimming element 13 may be a liquid crystal panel, hereinafter referred to as a second liquid crystal panel. However, the dimming element 13 may also take other forms. For example, the dimming element 13 may be a mechanical structure capable of adjusting the transmittance of the backlight.

[0066] In some embodiments, the resolution of the first liquid crystal panel 12 may be higher than the resolution of the second liquid crystal panel 13. For example, the resolution of the first liquid crystal panel 12 is M*N (e.g., 1280*640), and the resolution of the second liquid crystal panel 13 is m*n (e.g., 640*320), where M≥m and N≥n.

[0067] By making the resolution of the second liquid crystal panel 13 lower than that of the first liquid crystal panel 12, the light transmittance of the second liquid crystal panel 13 can be improved, enabling the second liquid crystal panel 13 to provide higher brightness, thereby further enhancing the contrast of the displayed image.

[0068] In some embodiments, each pixel of the first liquid crystal panel 12 may include a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and the second liquid crystal panel 13 may not include color sub-pixels.

[0069] In this configuration, the first liquid crystal panel 12 can display a full-color image using red, green, and blue sub-pixels, while the second liquid crystal panel 13 can provide higher brightness by excluding color sub-pixels, thereby further enhancing the contrast of the displayed image and increasing its color saturation.

[0070] In some embodiments, the second liquid crystal panel 13 may include two gray levels.

[0071] The first liquid crystal panel 12 can control the grayscale of its pixels, i.e., the display brightness, so that the displayed image has different levels of brightness, i.e., grayscale levels. For example, the first liquid crystal panel 12 may include at least 8 levels, totaling 256 (2 8 The second liquid crystal panel 13 can have one gray level. Each gray level represents a brightness level. More gray levels mean that the image can display richer details in both light and dark areas and smoother transitions, thus achieving a more realistic and delicate display effect. The second liquid crystal panel 13 can include one gray level, for a total of two gray levels. These two gray levels typically correspond to two states: on and off. In the on state, light can pass through the second liquid crystal panel 13, while in the off state, light cannot pass through the second liquid crystal panel 13. For example, the gray levels of the first area of ​​the second liquid crystal panel 13 can correspond to the on state, while the gray levels of other areas can correspond to the off state. In this way, the transmittance of backlight passing through the second liquid crystal panel 13 can be adjusted in a simple and low-cost manner.

[0072] However, the second LCD panel 13 can also include more gray levels.

[0073] In this case, these gray levels can be coordinated with the pulse width modulation (PWM) brightness levels of the LEDs of the backlight device 11 to achieve a wider range of image brightness display.

[0074] For example, the maximum brightness of a conventional LED image is 12,000 nits, but due to the limitations of the PWM design, the minimum brightness is 12 nits ((1 / 1000) * 12,000 nits). With the second LCD panel 13 including four gray levels (0, 1, 2, and 3), the minimum brightness can reach 4 nits (12 * (1 / 3) nits). This achieves a wider range of image brightness display.

[0075] As mentioned earlier, the eye box is the area within a HUD device where the user's eyes can move, and within this area, the user can clearly see the complete image. If the light does not cover the eye box, the image seen by the user may be blurry, distorted, or incomplete, affecting the visual experience. Therefore, the display light emitted from the PGU10 needs to diffuse within a certain angle range to cover the entire eye box.

[0076] Therefore, such as Figure 5 As shown, the dimming element 13 can be controlled so that the direction of some of the light emitted through the dimming element 13 is tilted relative to the direction of the incident light incident on the dimming element 13, so that the display light S emitted from the first liquid crystal panel 12 (i.e., emitted from PGU10) diffuses within a certain angle range, thereby covering the entire eye box.

[0077] However, in order to create display light that diffuses within a certain angle range, it may be necessary to increase the size of the first region of the dimming element 13. For example, for the dimming element 13 of a liquid crystal panel, in addition to the pixels in the first region corresponding to the second region, it may be necessary to illuminate several more pixels, such as... Figure 5 As shown, in addition to the vertical light rays emitted through the middle pixel, two more light rays are needed, one each emitted through the left and right pixels, to diffuse the displayed light within a certain angle range. This results in an increase in the amount of light illuminating the first liquid crystal panel 12, which is detrimental to reducing the temperature of the first liquid crystal panel 12. Moreover, the light may illuminate the peripheral areas of the first liquid crystal panel 12 outside the second area, thereby reducing the contrast between the displayed image content and the background.

[0078] In some implementation methods, reference is made to this. Figure 6 The PGU10 may also include a diffuser 14 disposed between the first liquid crystal panel 12 and the dimming element 13.

[0079] The diffuser 14 is used to diffuse the light emitted from it to form a diverging beam. By placing the diffuser 14 between the first liquid crystal panel 12 and the dimming element 13, light emitted from the dimming element 13 enters the diffuser 14 and passes through the first liquid crystal panel 12 in the form of a diverging beam. Figure 6 As shown, this creates a display light that diffuses within a certain angle range, thus covering the entire eye box.

[0080] Due to the arrangement of the diffuser 14, when the first and second regions are of the same size, the displayed light can be diffused within a certain angle range to cover the eye box. Furthermore, by appropriately setting the divergence angle of the emitted beam formed by the diffuser 14, the first region can be made slightly smaller than the second region, thereby further reducing the amount of light transmitted through the dimming element 13. For example, for a dimming element 13 that is a liquid crystal panel, such as... Figure 6 As shown, the display light can be diffused within a certain angle range by passing only light through a single pixel. Therefore, the amount of light illuminating the first liquid crystal panel 12 can be reduced without increasing or even decreasing the amount of light, thereby lowering the temperature of the first liquid crystal panel 12. Furthermore, since the first region is not enlarged, and the light emitted from the dimming element 13 is not tilted but diffused through the diffuser 14, it will not illuminate the peripheral area outside the second region, thus preventing a decrease in contrast.

[0081] In some implementations, refer to Figure 7 The diffuser 14 may have a structure for deflecting the central principal ray of the diverging beam formed therethrough.

[0082] like Figure 7 As shown, the diverging light beam S20 formed by the diffuser 14 has a divergence angle β, and the central principal ray S21 of the diverging light beam S20 is a ray located on the angle bisector of its divergence angle β. The central principal ray S21 forms an angle θ with the normal L of the first liquid crystal panel 12. Figure 6 In the case shown, the central principal ray S21 of the diverging beam S20 is not deflected, and the aforementioned included angle is zero.

[0083] By providing the diffuser 14 with the aforementioned deflection structure, the central principal ray S21 of the diverging beam S20 can be deflected (i.e., the included angle θ is not zero), thereby enabling the display light emitted from the first liquid crystal panel 12 to diffuse within a more suitable angle range for covering the eye box, so as to better cover the entire eye box.

[0084] For example, the deflection structure described above can be an inclined microlens, which can simultaneously deflect and diffuse light; or, the deflection structure described above can be an inclined microprism that serves as one surface of the diffuser 14 for deflecting light, in which case the diffuser 14 can also have a microstructure that serves as another surface for diffusering light.

[0085] In some implementations, refer to Figure 8 The PGU10 may also include a deflecting optical element 15, which is arranged on the side of the dimming element 13 near the backlight device 11 to deflect the light emitted therefrom.

[0086] In this case, a diffuser 14 can still be provided between the first liquid crystal panel 12 and the dimming element 13, and the diffuser 14 can only serve to diffuse the light emitted from it. By providing a deflecting optical element 15 on the side of the dimming element 13 near the backlight device 11, the backlight light S2 can be deflected before passing through the dimming element 13. Thus, through the diffusion effect of the diffuser 14, a diverging beam with the central main light beam deflected can be formed, thereby enabling the display light emitted from the first liquid crystal panel 12 to diffuse within a more suitable angle range for covering the eye box, so as to better cover the entire eye box.

[0087] In some implementations, refer to Figure 9 PGU10 may also include a first polarizing film 16 and a second polarizing film 17. The first polarizing film 16 is disposed on the side of the second liquid crystal panel 13 near the backlight device 11, and the second polarizing film 17 is disposed on the side of the second liquid crystal panel 13 near the first liquid crystal panel 12. Both the first polarizing film 16 and the second polarizing film 17 are reflective polarizing films.

[0088] Liquid crystal panels typically only allow polarized light to pass through, while the backlight provided by the backlight device 11 is usually natural light. Therefore, by providing a first polarizing film 16 on the side of the second liquid crystal panel 13 near the backlight device 11, the natural light emitted by the backlight device 11 can be converted into polarized light, allowing it to pass through the second liquid crystal panel 13 and illuminate the first liquid crystal panel 12. A second polarizing film 17, provided on the side of the second liquid crystal panel 13 near the first liquid crystal panel 12, can work together with the first polarizing film 16 and the liquid crystal layer to control the transmission and blocking of backlight light.

[0089] Furthermore, the reflective polarizing film can reflect light in one polarization direction and allow light in another polarization direction to pass through. By making both the first polarizing film 16 and the second polarizing film 17 reflective polarizing films, light in one polarization direction that would otherwise be absorbed by the second liquid crystal panel 12 can be reflected, thereby reducing the impact of backlight on the temperature of the second liquid crystal panel 12, and consequently also reducing the impact of backlight on the temperature of the first liquid crystal panel 12.

[0090] The control device will now be described in further detail.

[0091] In some examples, the control device has communication capabilities and can access wired or wireless networks. In some examples, the control device can receive data based on the accessed wired or wireless network. It is understood that the control device undertakes the calculation and processing work of the technical solutions disclosed herein, and this disclosure does not limit it in this regard.

[0092] In some examples, the control device has communication capabilities, accesses a wired or wireless network, obtains the temperature, time, and sunshine conditions at the vehicle's location, and outputs a solar backflow protection strategy based on whether there is solar backflow. For example, by using the PGU according to an embodiment of this disclosure, the display panel's tolerance to solar backflow energy is improved.

[0093] The control device disclosed herein may include one or more of the following components: a processor and a memory. Optionally, the processor connects various parts within the control device using various interfaces and lines, and performs various functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory, and by calling data stored in the memory. Optionally, the processor may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), Neural-network Processing Unit (NPU), and baseband chip. The CPU primarily handles the operating system, UI, and applications; the GPU is responsible for rendering and drawing the content to be displayed on the touch screen; the NPU implements Artificial Intelligence (AI) functions; and the baseband chip handles wireless communication. It is understood that the baseband chip may also be implemented as a separate chip without being integrated into the processor.

[0094] The memory may include random access memory (RAM) or read-only memory (ROM). Optionally, the memory may include a non-transitory computer-readable storage medium. The memory can be used to store instructions, programs, code, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch functionality, sound playback functionality, image playback functionality, etc.), instructions for implementing the various method embodiments described above, etc., and the data storage area may store data created based on the use of the control device, etc.

[0095] In addition, those skilled in the art will understand that the control device may include more or fewer components than those described above, or combine certain components, or have different component arrangements. For example, the control device may also include a display screen, camera assembly, radio frequency circuit, input unit, sensor, audio circuit, WiFi module, power supply, Bluetooth module, etc., which will not be described in detail here.

[0096] According to another aspect of this disclosure, such as Figure 10 As shown, a HUD device 1 is also provided, which includes the aforementioned PGU10.

[0097] In addition, the HUD device 1 may also include a reflecting device, such as a first reflector 20 and a second reflector 30, so that the display light S emitted by the PGU10 can be emitted from the HUD device 1 after being reflected by the second reflector 30 and the first reflector 20 in sequence.

[0098] In this disclosure, the terms "first," "second," etc., are used merely for descriptive purposes and should not be considered restrictive. Furthermore, although this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the specific embodiments described and shown herein. Various changes to the exemplary embodiments can be made by those skilled in the art without departing from the scope defined by the claims of this disclosure.

[0099] The features mentioned and / or shown in the foregoing description of exemplary embodiments of this disclosure may be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. Such combinations or substitutions should also be considered as including within the scope of protection of this disclosure.

Claims

1. An image generation unit characterized by comprising: including: a backlight device configured to provide a backlight; a first liquid crystal panel disposed on a side of the backlight device on which the backlight is provided and configured to display an image; a light adjusting element disposed between the first liquid crystal panel and the backlight device and configured to adjust a transmittance of the backlight transmitted through the light adjusting element; and a control device configured to control the light adjusting element so that only a first region of the light adjusting element allows the backlight to be transmitted to irradiate an entire second region of the first liquid crystal panel that displays a display content of the image displayed by the first liquid crystal panel, according to the display content of the image displayed by the first liquid crystal panel, wherein the first region corresponds to the second region in shape and size. The light adjusting element is a second liquid crystal panel.

2. The image generation unit of claim 1, wherein, A resolution of the first liquid crystal panel is higher than a resolution of the second liquid crystal panel.

3. The image generation unit of claim 2, wherein, Each pixel of the first liquid crystal panel includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and the second liquid crystal panel does not include a color sub-pixel.

4. The image generation unit of claim 2, wherein, The second liquid crystal panel includes two or more gray scales.

5. The image generation unit of claim 2, wherein, Further including a diffusion sheet disposed between the first liquid crystal panel and the light adjusting element.

6. The image generation unit of claim 1, wherein, The diffusion sheet has a structure for deflecting a central chief ray of a diverging light beam formed therethrough.

7. The image generation unit of claim 6, wherein, Further including a deflection optical element disposed on a side of the light adjusting element close to the backlight device for deflecting light rays emerging therefrom.

8. The image generation unit of claim 6, wherein, The second liquid crystal panel includes a first polarizing film disposed on a side of the second liquid crystal panel close to the backlight device and a second polarizing film disposed on a side of the second liquid crystal panel close to the first liquid crystal panel, and the first and second polarizing films are both reflective polarizing films.

9. The image generation unit of claim 2, wherein, including:

10. An image generation unit characterized by comprising: a backlight device configured to provide a backlight; a first liquid crystal panel disposed on a side of the backlight device on which the backlight is provided and configured to display an image; a light adjusting element disposed between the first liquid crystal panel and the backlight device and configured to adjust a transmittance of the backlight transmitted through the light adjusting element; and a control device configured to control the light adjusting element so that only a first region of the light adjusting element allows the backlight to be transmitted to irradiate an entire second region of the first liquid crystal panel that displays a display content of the image displayed by the first liquid crystal panel, according to the display content of the image displayed by the first liquid crystal panel, wherein the first region corresponds to the second region in shape and size. The first region is expanded outward relative to the second region by a distance of 2 to 24 pixels. including the image generation unit according to any one of claims 1 to 11.

11. The image generation unit of claim 10, wherein, ​ 12. A head-up display device, characterized by ​

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