Head-up display, head-up display system and vehicle

Abstract

The invention relates to a head-up display, a head-up display system and a vehicle, and the head-up display uses a polarization conversion part to change the polarization characteristic of one of first image light and second image light, so that the polarization characteristics of the first image light and the second image light are different. The image light with the first polarization characteristic is reflected by the polarization transflective part, the image light with the second polarization characteristic is transmitted by the polarization transflective part, a first virtual image is formed after the image light with the first polarization characteristic is reflected by the polarization transflective part, and a second virtual image is formed after the image light with the second polarization characteristic is transmitted by the polarization transflective part; the imaging light paths and the imaging positions of the first virtual image and the second virtual image are different, so that double-layer images imaged at different positions are realized, the problem of visual fatigue caused by visual convergence is solved, and the use experience of a user is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of head-up display, and in particular to a head-up display, a head-up display system and a vehicle. Background Art

[0002] A head up display (HUD), also known as a head-up display, projects the image light output by the image generation unit of the HUD onto the imaging part. The image light is reflected by the imaging part and reaches the eye box area. When the user's eyes are in the eye box area, the user can see the virtual image in front of the imaging part, avoiding the driver's distraction caused by looking down at the dashboard during driving, thereby improving driving safety and bringing a better driving experience.

[0003] In the related art, the imaging screen (i.e., virtual image) formed by the HUD is generally a single-layer screen, and the imaging position of the single-layer screen is basically fixed. When using it, the user needs to switch his or her line of sight between the single-layer screen at the fixed position of the HUD and the real scenes at different distances (such as the road ahead, the intersection ahead, the vehicle in front, etc.), which will cause visual convergence problems, causing the user to experience visual fatigue such as blurring, dizziness, and diplopia, which seriously reduces the user's experience. Summary of the invention

[0004] In order to solve the above technical problems, the present disclosure provides a head-up display, a head-up display system and a vehicle.

[0005] In a first aspect, the present disclosure provides a head-up display, comprising:

[0006] An image generating unit, configured to alternately output a first image light and a second image light according to a preset timing; the first image light and the second image light have a first polarization characteristic;

[0007] a polarization conversion unit, located in the outgoing light path of the image generating unit; the polarization conversion unit is used to convert the polarization characteristic of one of the first image light and the second image light into a second polarization characteristic based on the preset timing;

[0008] The polarization transflection section is located in the output light path of the polarization conversion section; the polarization transflection section is used to reflect image light with a first polarization characteristic, and the image light reflected by the polarization transflection section is used to form a first virtual image; the polarization transflection section is also used to transmit image light with a second polarization characteristic, and the image light transmitted by the polarization transflection section is used to form a second virtual image.

[0009] Optionally, a line connecting the virtual image center of the first virtual image and the center of the eye box area does not coincide with a line connecting the virtual image center of the second virtual image and the center of the eye box area.

[0010] Optionally, the polarization conversion unit includes an electrically controlled liquid crystal polarization element; the head-up display further includes: a first control module;

[0011] The first control module is used to control the on and off of the electrically-controlled liquid crystal polarization element based on the preset timing; wherein the electrically-controlled liquid crystal polarization element converts the polarization characteristics of one of the first image light and the second image light into a second polarization characteristic when powered on, and the electrically-controlled liquid crystal polarization element does not change the polarization characteristics of the first image light and the second image light when powered off.

[0012] Optionally, the electrically controlled liquid crystal polarization element comprises an incident surface, an exit surface and a liquid crystal box, and the liquid crystal box is located between the incident surface and the exit surface;

[0013] Among them, when the electrically-controlled liquid crystal polarization element is powered off, the liquid crystal molecules in the liquid crystal box remain in the first direction and do not change the polarization characteristics of the image light incident from the incident surface; when the electrically-controlled liquid crystal polarization element is powered on, the liquid crystal molecules in the liquid crystal box rotate from the first direction to the second direction, converting the polarization characteristics of the image light incident from the incident surface into the second polarization characteristics.

[0014] Optionally, the polarization conversion unit includes a movable polarization conversion element; the head-up display further includes: a second control module;

[0015] The second control module is used to control the movable polarization conversion element to switch between a first position and a second position based on the preset timing; wherein, when the movable polarization conversion element is located at the first position, the movable polarization conversion element is in the output light path of the image generating unit, and converts the polarization characteristics of the image light output by the image generating unit into the second polarization characteristics; when the movable polarization conversion element is located at the second position, the movable polarization conversion element is not in the output light path of the image generating unit, and does not change the polarization characteristics of the image light output by the image generating unit.

[0016] Optionally, the image light with the first polarization characteristic is horizontal linear polarized light, and the image light with the second polarization characteristic is vertical linear polarized light, and the polarization transflective portion is used to reflect the horizontal linear polarized light and transmit the vertical linear polarized light; or,

[0017] The image light with the first polarization characteristic is vertical linear polarized light, and the image light with the second polarization characteristic is horizontal linear polarized light. The polarization transflective portion is used to reflect the vertical linear polarized light and transmit the horizontal linear polarized light.

[0018] Optionally, the head-up display further includes:

[0019] a reflective element, located in the optical path between the image generating unit and the polarized transflective portion, and configured to reflect the first image light and the second image light output by the image generating unit to the polarized transflective portion;

[0020] The polarization conversion section is located in the light path between the image generation unit and the reflective element, or in the light path between the reflective element and the polarization transflective section.

[0021] Optionally, the reflective element includes a plane reflector, or a first curved reflector, or a plane reflector and a first curved reflector.

[0022] Optionally, the head-up display further includes:

[0023] A second curved reflector is located in the reflective light path of the polarized reflective portion, and the image light reflected by the second curved reflector is used to form a first virtual image;

[0024] In the imaging optical path of the second virtual image, the image light output by the image generating unit for forming the second virtual image does not pass through the second curved reflector.

[0025] In a second aspect, the present disclosure further provides a head-up display system, comprising: a reflective imaging unit and any of the above-mentioned head-up displays;

[0026] The reflective imaging part is located in the reflective light path of the polarized transflective part, and is used to reflect the image light reflected by the polarized transflective part to the eye box area to form a first virtual image.

[0027] Optionally, in the imaging light path of the second virtual image, the image light output by the image generating unit for forming the second virtual image does not pass through the reflective imaging portion.

[0028] Optionally, the reflective imaging portion includes an imaging plate or a windshield.

[0029] In a third aspect, the present disclosure further provides a means of transportation, comprising: any one of the above-mentioned head-up display systems.

[0030] Compared with the prior art, the technical solution provided by the present invention has the following advantages:

[0031] The present disclosure provides a head-up display, a head-up display system and a vehicle. The head-up display uses a polarization conversion unit to change the polarization characteristics of one of the first image light and the second image light, so that the polarization characteristics of the first image light and the second image light are different, and then uses a polarization transmission and reflection unit to reflect the image light with the first polarization characteristic and transmit the image light with the second polarization characteristic. The image light with the first polarization characteristic is reflected by the polarization transmission and reflection unit to form a first virtual image, and the image light with the second polarization characteristic is transmitted by the polarization transmission and reflection unit to form a second virtual image. The imaging optical paths and imaging positions of the first virtual image and the second virtual image are different, thereby realizing a double-layer screen formed at different positions, solving the problem of visual fatigue caused by visual convergence and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0034] Figure 1 A schematic diagram of the structure of a head-up display system provided in an embodiment of the present disclosure;

[0035] Figure 2 A schematic diagram of the structure of another head-up display system provided in an embodiment of the present disclosure;

[0036] Figure 3 A schematic diagram of the structure of another head-up display system provided in an embodiment of the present disclosure;

[0037] Figure 4 A schematic diagram of the structure of another head-up display system provided in an embodiment of the present disclosure.

[0038] Among them, 100, head-up display; 1, image generating unit; 2, polarization conversion unit; 21, electrically controlled liquid crystal polarization element; 22, movable polarization conversion element; 3, polarization transflective unit; 4, reflecting element; 5, reflecting imaging unit; 6, first virtual image; 7, second virtual image. DETAILED DESCRIPTION

[0039] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0041] The head-up display, head-up display system and vehicle provided in the embodiments of the present disclosure are exemplarily described below with reference to the accompanying drawings.

[0042] In some embodiments, Figure 1-4 As shown in any figure, the head-up display 100 includes: an image generation unit 1, a polarization conversion unit 2 and a polarization transflection unit 3. The image generation unit 1 is used to alternately output a first image light and a second image light according to a preset timing; the first image light and the second image light have a first polarization characteristic; the polarization conversion unit 2 is located in the output light path of the image generation unit 1; the polarization conversion unit 2 is used to convert the polarization characteristic of one of the first image light and the second image light into a second polarization characteristic based on the preset timing; the polarization transflection unit 3 is located in the output light path of the polarization conversion unit 2; the polarization transflection unit 3 is used to reflect the image light with the first polarization characteristic, and the image light reflected by the polarization transflection unit 3 is used to form a first virtual image 6; the polarization transflection unit 3 is also used to transmit the image light with the second polarization characteristic, and the image light transmitted by the polarization transflection unit 3 is used to form a second virtual image 7.

[0043] Among them, the image generation unit 1 is a time-sequential electrically controlled image source, and the polarization conversion unit 2 is a time-sequential polarization conversion element, and both respond to the control of the same timing circuit. Based on the control instruction received, the image generation unit 1 outputs the image light corresponding to the image to be displayed; the control instruction includes the image information to be displayed and the preset timing, and the image generation unit 1 outputs the corresponding image light according to the preset timing. For example, at the Nth moment, the image generation unit 1 outputs the first image light; at the N+1th moment, the image generation unit 1 outputs the second image light, and so on; N is a positive integer greater than or equal to 1, and the time interval between adjacent moments is the time step of the image generation unit 1 outputting the image light, such as a frame interval. The image information carried in the first image light is different from the image information carried by the second image light, that is, the first image light and the second image light are used to form images with different contents.

[0044] Due to the persistence of vision phenomenon, although the image generating unit 1 outputs the first image light and the second image light alternately, that is, the image generating unit 1 does not output the first image light and the second image light at the same time, the human eye can still see the first virtual image 6 and the second virtual image 7 at the same time.

[0045] The polarization characteristics of the first image light and the second image light are the same, and the polarization characteristics of both are the first polarization characteristics. The first polarization characteristic includes one of horizontal linear polarization and vertical linear polarization, and the second polarization characteristic includes the other of horizontal linear polarization and vertical linear polarization. Exemplarily, the polarization direction of the first polarization characteristic is perpendicular to the polarization direction of the second polarization characteristic. If the image light with the first polarization characteristic is vertical linear polarization light (i.e., S polarization light), the image light with the second polarization characteristic is horizontal linear polarization light (i.e., P polarization light); if the image light with the first polarization characteristic is P polarization light, the image light with the second polarization characteristic is S polarization light.

[0046] Among them, according to the preset timing of the image light output by the image generating unit 1, the polarization conversion unit 2 is controlled to work within the target timing, which can change the polarization characteristics of the image light output by the image generating unit 1 at the target timing, so that the polarization characteristics of the image light are converted from the first polarization characteristics to the second polarization characteristics; the polarization characteristics of the image light output by the image generating unit 1 at the non-target timing will not be changed, and will still be the first polarization characteristics, so that the polarization characteristics of the first image light emitted from the polarization conversion unit 2 at different timings are different from the polarization characteristics of the second image light.

[0047] Exemplarily, the timing of the image generation unit 1 outputting the first image light is determined to be the target timing, the timing of the second image light is determined to be the non-target timing, the polarization conversion unit 2 works at the target timing and does not work at the non-target timing, so that the first image light emitted from the polarization conversion unit 2 is converted from the first polarization characteristic to the second polarization characteristic, and the second image light emitted from the polarization conversion unit 2 still has the first polarization characteristic. For example, at the Nth moment, the image generation unit 1 outputs the first image light with the first polarization characteristic, the polarization conversion unit 2 changes the polarization characteristic of the first image light, and the first image light emitted from the polarization conversion unit 2 has the second polarization characteristic; at the N+1th moment, the image generation unit 1 outputs the second image light with the first polarization characteristic, the polarization conversion unit 2 does not change the polarization characteristic of the second image light, and the second image light emitted from the polarization conversion unit 2 still has the first polarization characteristic.

[0048] Exemplarily, the timing of the image generation unit 1 outputting the second image light is determined to be the target timing, the timing of the first image light output is determined to be the non-target timing, the polarization conversion unit 2 works at the target timing and does not work at the non-target timing, so that the second image light emitted from the polarization conversion unit 2 is converted from the first polarization characteristic to the second polarization characteristic, and the first image light emitted from the polarization conversion unit 2 still has the first polarization characteristic. For example, at the Nth moment, the image generation unit 1 outputs the first image light with the first polarization characteristic, the polarization conversion unit 2 does not change the polarization characteristic of the first image light, and the first image light emitted from the polarization conversion unit 2 still has the first polarization characteristic; at the N+1th moment, the image generation unit 1 outputs the second image light with the first polarization characteristic, the polarization conversion unit 2 changes the polarization characteristic of the second image light, and the second image light emitted from the polarization conversion unit 2 has the second polarization characteristic.

[0049] The polarized reflective section 3 has the function of reflecting image light with a first polarization characteristic and transmitting image light with a second polarization characteristic, so that the image light with the first polarization characteristic and the image light with the second polarization characteristic propagate along different optical paths, thereby forming two virtual images with different imaging positions and imaging distances. The image light with the first polarization characteristic is used to form the first virtual image 6, and the image light with the second polarization characteristic is used to form the second virtual image 7. In the imaging optical path of the first virtual image 6, the image light used to form the first virtual image 6 is reflected when incident on the polarized reflective section 3; and the image light used to form the second virtual image 7 is transmitted through the polarized reflective section 3 when incident on the polarized reflective section 3, and the imaging optical paths of the first virtual image 6 and the second virtual image 7 are different.

[0050] For example, Figure 1-4 As shown in any figure, the image light output by the image generating unit 1 is S polarized light (marked as "S light" in the figure), that is, the first image light and the second image light output from the image generating unit 1 are both S polarized light. After passing through the polarization conversion unit 2, one of the first image light and the second image light is converted from S polarized light to P polarized light (marked as "P light" in the figure), and the other is still S polarized light. The polarization transflective unit 3 reflects the S polarized light to form a first virtual image 6, and the polarization transflective unit 3 transmits the P polarized light to form a second virtual image 7. The imaging positions and imaging optical paths of the first virtual image 6 and the second virtual image 7 are different, and visually produce the effect of two virtual images with different depths of field, that is, a double-layer picture with imaging at different positions is realized, which solves the problem of visual fatigue caused by visual convergence and improves the user experience.

[0051] The specific process of image light forming the first virtual image 6 and the second virtual image 7 is as follows: at the Nth moment, the image generating unit 1 outputs the first image light, and after passing through the polarization conversion unit 2, the first image light is converted from S polarized light to P polarized light, and the first image light emitted from the polarization conversion unit 2 is incident on the polarization transmission and reflection unit 3, and the polarization transmission and reflection unit 3 transmits the first image light to form the second virtual image 7; at the N+1th moment, the image generating unit 1 outputs the second image light, and after passing through the polarization conversion unit 2, the polarization characteristic of the second image light does not change and is still S polarized light, and the second image light emitted from the polarization conversion unit 2 is incident on the polarization transmission and reflection unit 3, and the polarization transmission and reflection unit 3 reflects the second image light. , to form a first virtual image 6; or, at the Nth moment, the image generating unit 1 outputs the first image light, and after passing through the polarization conversion unit 2, the polarization characteristics of the first image light do not change, and are still S-polarized light, the first image light emitted from the polarization conversion unit 2 is incident on the polarization transflection unit 3, and the polarization transflection unit 3 reflects the first image light to form the first virtual image 6; at the N+1th moment, the image generating unit 1 outputs the second image light, and after passing through the polarization conversion unit 2, the S-polarized light of the second image light is converted into P-polarized light, the second image light emitted from the polarization conversion unit 2 is incident on the polarization transflection unit 3, and the polarization transflection unit 3 transmits the second image light to form the second virtual image 7. In addition, the first virtual image 6 is formed by S-polarized light, and the second virtual image 7 is formed by P-polarized light. The second virtual image 7 is used to display important information such as instruments. In the scenario where the user wears polarized sunglasses (transmitting P-polarized light and filtering S-polarized light), the user can still view the second virtual image 7 normally, which is convenient for the user to view important information such as instruments displayed in the second virtual image, thereby improving driving safety.

[0052] In some embodiments, an imaging distance (Virtual Image Distance, VID) of the first virtual image 6 is greater than an imaging distance of the second virtual image 7 , the first virtual image 6 is used to display augmented reality information, and the second virtual image 7 is used to display non-augmented reality information.

[0053] It should be noted that the embodiment of the present disclosure does not limit the polarization characteristics of the image light output by the image generating unit 1. Figure 1-4 It is only shown by way of example that the image light output by the image generating unit 1 is S polarized light. In other embodiments, the image light output by the image generating unit 1 may also be P polarized light. In this case, the first virtual image 6 is formed by P polarized light, and the second virtual image 7 is formed by S polarized light.

[0054] The head-up display 100 provided in the embodiment of the present disclosure utilizes the polarization conversion unit 2 to change the polarization characteristics of one of the first image light and the second image light, so that the polarization characteristics of the first image light and the second image light are different, and then utilizes the polarization transmission and reflection unit 3 to reflect the image light with the first polarization characteristic and transmit the image light with the second polarization characteristic. The image light with the first polarization characteristic is reflected by the polarization transmission and reflection unit 3 to form a first virtual image 6, and the image light with the second polarization characteristic is transmitted by the polarization transmission and reflection unit 3 to form a second virtual image 7. The imaging optical paths and imaging positions of the first virtual image 6 and the second virtual image 7 are different, thereby realizing a double-layer screen formed at different positions, solving the problem of visual fatigue caused by visual convergence, and improving the user experience.

[0055] In some embodiments, a line connecting the virtual image center of the first virtual image 6 and the center of the eye box area does not coincide with a line connecting the virtual image center of the second virtual image 7 and the center of the eye box.

[0056] In this embodiment, the imaging positions and imaging distances of the first virtual image 6 and the second virtual image 7 are different, and the two virtual images are not coaxial, and the first virtual image 6 and the second virtual image 7 are used to display different contents. For example, the near-layer virtual image (virtual image with a small imaging distance) is used to display information such as instant messaging and phone notifications, and the far-layer virtual image (virtual image with a large imaging distance) is used to display audio and video content, augmented reality information, etc.

[0057] In some embodiments, Figure 1 As shown in or 3, the polarization conversion unit 2 includes an electrically controlled liquid crystal polarization element 21; the head-up display 100 also includes: a first control module (not shown in the figure); the first control module is used to control the on and off of the electrically controlled liquid crystal polarization element 21 based on a preset timing; wherein, the electrically controlled liquid crystal polarization element 21 will change the polarization characteristics of the image light incident to the electrically controlled liquid crystal polarization element 21 under the energized condition, that is, convert the polarization characteristics of one of the first image light and the second image light into the second polarization characteristics, and the electrically controlled liquid crystal polarization element 21 will not change the polarization characteristics of the image light incident to the electrically controlled liquid crystal polarization element 21 under the energized condition.

[0058] In this embodiment, the polarization conversion unit 2 is an electrically controlled liquid crystal polarization element 21. By controlling the on and off of the electrically controlled liquid crystal polarization element 21, one of the first image light and the second image light is converted from the first polarization characteristic to the second polarization characteristic, and the polarization characteristic of the other does not change and remains the first polarization characteristic, so that the polarization characteristics of the first image emitted from the polarization conversion unit 2 are different from the polarization characteristics of the second image.

[0059] Exemplarily, the first image light and the second image light output by the image generating unit 1 are S-polarized light. At the moment when the image generating unit 1 outputs the first image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be energized, and the electrically-controlled liquid crystal polarization element 21 converts the incident first image light into P-polarized light and then outputs it. At the moment when the image generating unit 1 outputs the second image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be deenergized, and the electrically-controlled liquid crystal polarization element 21 will not change the deflection characteristics of the incident second image light, and the second image light is still S-polarized light after being emitted by the electrically-controlled liquid crystal polarization element 21; or, at the moment when the image generating unit 1 outputs the first image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be deenergized, and the electrically-controlled liquid crystal polarization element 21 will not change the deflection characteristics of the incident first image light, and the first image light is still S-polarized light after being emitted by the electrically-controlled liquid crystal polarization element 21. At the moment when the image generating unit 1 outputs the second image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be energized, and the electrically-controlled liquid crystal polarization element 21 converts the incident second image light into P-polarized light and then outputs it.

[0060] Exemplarily, the first image light and the second image light output by the image generating unit 1 are P-polarized light. At the moment when the image generating unit 1 outputs the first image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be energized, and the electrically-controlled liquid crystal polarization element 21 converts the incident first image light into S-polarized light and then outputs it. At the moment when the image generating unit 1 outputs the second image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be deenergized, and the electrically-controlled liquid crystal polarization element 21 will not change the deflection characteristics of the incident second image light, and the second image light is still P-polarized light after being emitted by the electrically-controlled liquid crystal polarization element 21; or, at the moment when the image generating unit 1 outputs the first image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be deenergized, and the electrically-controlled liquid crystal polarization element 21 will not change the deflection characteristics of the incident first image light, and the first image light is still P-polarized light after being emitted by the electrically-controlled liquid crystal polarization element 21. At the moment when the image generating unit 1 outputs the second image light, the electrically-controlled liquid crystal polarization element 21 is controlled to be energized, and the electrically-controlled liquid crystal polarization element 21 converts the incident second image light into S-polarized light and then outputs it.

[0061] In some embodiments, the electrically-controlled liquid crystal polarization element 21 includes an incident surface, an exit surface and a liquid crystal box, and the liquid crystal box is located between the incident surface and the exit surface; wherein, when the electrically-controlled liquid crystal polarization element 21 is powered off, the liquid crystal molecules in the liquid crystal box remain in the first direction and do not change the polarization characteristics of the image light incident from the incident surface; when the electrically-controlled liquid crystal polarization element 21 is powered on, the liquid crystal molecules in the liquid crystal box rotate from the first direction to the second direction, converting the polarization characteristics of the image light incident from the incident surface into the second polarization characteristics.

[0062] In this embodiment, the electrically controlled liquid crystal polarization element 21 includes an incident surface, an exit surface, and a liquid crystal box, the liquid crystal box is sandwiched between the incident surface and the exit surface, and electrodes are arranged on the incident surface and the exit surface. When the first control module controls the electrically controlled liquid crystal polarization element 21 to be powered off, there is no voltage on the electrodes, the liquid crystal molecules in the liquid crystal box will not rotate and remain in the first direction, at this time, the polarization characteristics of the image light incident from the incident surface will not be changed, and the image light is emitted from the exit surface. When the first control module controls the electrically controlled liquid crystal polarization element 21 to be powered on, a voltage is applied to the electrodes, the liquid crystal molecules in the liquid crystal box rotate from the first direction to the second direction, at this time, the image light incident from the incident surface is converted from the first polarization characteristic to the second polarization characteristic, and is emitted from the exit surface.

[0063] The electrically controlled liquid crystal polarizing element 21 includes an electrically controlled liquid crystal polarizing plate, and the electrodes include indium tin oxide (ITO) transparent electrodes, and also include all electrodes known to those skilled in the art, which are not limited here.

[0064] In some embodiments, Figure 2 As shown in or 4, the polarization conversion unit 2 includes a mobile polarization conversion element 22; the head-up display 100 also includes: a second control module (not shown in the figure); the second control module is used to control the mobile polarization conversion element 22 to switch between a first position and a second position based on a preset timing; wherein, when the mobile polarization conversion element is located at the first position, the mobile polarization conversion element 22 is in the output light path of the image generation unit 1, and converts the polarization characteristics of the image light output by the image generation unit 1 into a second polarization characteristic; when the mobile polarization conversion element 22 is located at the second position, the mobile polarization conversion element 22 is not in the output light path of the image generation unit 1, and does not change the polarization characteristics of the image light output by the image generation unit 1.

[0065] The movable polarization conversion element 22 includes all components with polarization conversion characteristics known to those skilled in the art, such as a polarizer or a half-wave plate, which is not limited here.

[0066] For example, Figure 2 Or as shown in 4, at the Nth moment, the movable polarization conversion element 22 is located at the second position (i.e., the dotted line position in the figure), and the image light output by the image generating unit 1 does not pass through the movable polarization conversion element 22, so that the polarization characteristics of the image light will not be changed; at the N+1th moment, the movable polarization conversion element 22 moves along the moving direction shown in the figure to the first position (i.e., the solid line position in the figure), and the image light output by the image generating unit 1 passes through the movable polarization conversion element 22, and the polarization characteristics of the image light are changed, and the polarization characteristics are converted from the first polarization characteristics to the second polarization characteristics.

[0067] In some embodiments, the image light with the first polarization characteristic is horizontal linear polarized light (ie, P polarized light), the image light with the second polarization characteristic is vertical linear polarized light (ie, S polarized light), and the polarization transflective portion 3 is used to reflect P polarized light and transmit S polarized light.

[0068] In some embodiments, Figure 1-4 As shown in any figure, the image light with the first polarization characteristic is vertical linear polarized light (ie, S polarized light), and the image light with the second polarization characteristic is horizontal linear polarized light (ie, P polarized light). The polarization transflective portion 3 is used to reflect the S polarized light and transmit the P polarized light.

[0069] In some embodiments, the polarization transflective portion 3 includes a polarization transflective film.

[0070] In some embodiments, Figure 1 As shown in FIG. 2 , the head-up display 100 further includes: a reflective element 4, which is located in the optical path between the image generation unit 1 and the polarized transflective portion 3, and is used to reflect the first image light and the second image light output by the image generation unit 1 to the polarized transflective portion 3. The polarization conversion portion 2 is located in the optical path between the image generation unit 1 and the reflective element 4.

[0071] For example, Figure 1 Or as shown in 2, at the Nth moment, the image generating unit 1 outputs the first image light (taking S polarized light as an example), the first image light is incident on the polarization conversion unit 2 controlled by the timing circuit, the timing circuit controls the polarization conversion unit 2 not to change the polarization characteristics of the incident image light, the first image light passes through the polarization conversion unit 2 and then is incident on the reflecting element 4, is reflected by the reflecting element 4 to the polarization transmission and reflection unit 3, the polarization transmission and reflection unit 3 reflects the first image light to form a first virtual image 6; at the N+1th moment, the image generating unit 1 outputs the second image light (also S polarized light), the second image light is incident on the polarization conversion unit 2 controlled by the timing circuit, the timing circuit controls the polarization conversion unit 2 to change the polarization characteristics of the incident image light, the second image light is converted into P polarized light by the polarization conversion unit 2 and emitted, the second image light converted into P polarized light is reflected by the reflecting element 4 to the polarization transmission and reflection unit 3, the second image light converted into P polarized light is transmitted through the polarization transmission and reflection unit 3 to form a second virtual image 7.

[0072] In some embodiments, Figure 3 As shown in FIG. 4 , in the head-up display 100 , the polarization conversion part 2 is located in the optical path between the reflective element 4 and the polarization transflective part 3 .

[0073] For example, Figure 3Or as shown in 4, at the Nth moment, the image generating unit 1 outputs the first image light (taking S polarized light as an example), the first image light is reflected by the reflecting element 4 to the polarization conversion part 2, the timing circuit controls the polarization conversion part 2 not to change the polarization characteristics of the incident image light, and the first image light is incident on the polarization transmission and reflection part 3 after being emitted by the polarization conversion part 2, the polarization transmission and reflection part 3 reflects the first image light, and the first image light is reflected by the polarization transmission and reflection part 3 to form a first virtual image 6; at the N+1th moment, the image generating unit 1 outputs the second image light (also S polarized light), the second image light is reflected by the reflecting element 4 to the polarization conversion part 2, the timing circuit controls the polarization conversion part 2 to change the polarization characteristics of the incident image light, the second image light is converted into P polarized light by the polarization conversion part 2 and emitted, the second image light converted into P polarized light is emitted toward the polarization transmission and reflection part 3, and is transmitted through the polarization transmission and reflection part 3 to form a second virtual image 7.

[0074] In some embodiments, Figure 1-4 As shown in any of the figures, the reflective element 4 includes a plane reflective mirror.

[0075] In some embodiments, the reflective element 4 comprises a first curved reflector.

[0076] In some embodiments, the reflective element 4 includes a plane reflector and a first curved reflector.

[0077] It should be noted that Figure 4 The number of the reflective element is only one, which does not constitute a limitation on the head-up display provided by the embodiment of the present disclosure. In other embodiments, the number of the reflective elements may also be two, three or more, which is not limited here.

[0078] In some embodiments, the head-up display 100 further includes: a second curved reflector (not shown in the figure), the second curved reflector is located in the reflection light path of the polarization transflective portion 3, and the image light reflected by the second curved reflector is used to form a first virtual image 6.

[0079] In the imaging optical path of the second virtual image, the image light output by the image generation unit 1 for forming the second virtual image is transmitted through the polarization transflection unit 3, and does not pass through the second curved reflector. The imaging optical paths of the first virtual image 6 and the second virtual image 7 are different, and the imaging distance of the first virtual image 6 is greater than the imaging distance of the second virtual image 7, visually producing the effect that the two virtual images have different depths of field, that is, realizing a double-layer screen with imaging at different positions, solving the problem of visual fatigue caused by visual convergence, and improving the user experience.

[0080] On the basis of the above-mentioned implementation manner, the embodiment of the present disclosure further provides a head-up display system, which includes any of the above-mentioned head-up displays 100 and has corresponding beneficial effects. To avoid repeated description, they are not described here again.

[0081] In some embodiments, Figure 1-4 As shown in any of the figures, the head-up display system also includes: a reflective imaging unit 5; wherein the reflective imaging unit 5 is located in the reflective light path of the polarized transflective unit 3, and is used to reflect the image light reflected by the polarized transflective unit 3 to the eye box area to form a first virtual image 6; in the imaging light path of the second virtual image 7, the image light output by the image generation unit 1 for forming the second virtual image 7 does not pass through the reflective imaging unit 5.

[0082] In some embodiments, the polarized transflective portion 3 is used to reflect image light having a first polarization characteristic to the reflective imaging portion 5, so that the reflective imaging portion 5 reflects the image light incident to the reflective imaging portion 5 to the eye box area, and the image light reflected by the reflective imaging portion 5 is used to form a first virtual image 6; the polarized transflective portion 3 is also used to transmit image light having a second polarization characteristic to the eye box area, and the image light transmitted by the polarized transflective portion 3 is used to form a second virtual image 7.

[0083] In some embodiments, the second curved reflector is located in the light path between the polarized transflective portion 3 and the reflective imaging portion 5; the second curved reflector is used to reflect the image light reflected by the polarized transflective portion 3 to the reflective imaging portion 5, so that the reflective imaging portion 5 reflects the image light incident to the reflective imaging portion 5 to the eye box area.

[0084] For example, in the head-up display system, if Figure 1-4 As shown in any of the figures, the image light output by the image generating unit 1 is S polarized light (marked as "S light" in the figure), that is, the first image light and the second image light output from the image generating unit 1 are both S polarized light. After passing through the polarization conversion unit 2, one of the first image light and the second image light is converted from S polarized light to P polarized light (marked as "P light" in the figure), and the other is still S polarized light. The polarized reflection part 3 reflects the S polarized light to the reflective imaging part 5, and the reflective imaging part 5 reflects the S polarized light to the eye box area to form a first virtual image 6. The polarized reflection part 3 transmits the P polarized light to form a second virtual image 7 on the side of the polarized reflection part 3 away from the eye box area. The imaging positions and imaging optical paths of the first virtual image 6 and the second virtual image 7 are different, and visually produce the effect of two virtual images with different depths of field, that is, a double-layer picture formed at different positions is realized, which solves the problem of visual fatigue caused by visual convergence and improves the user experience.

[0085] In some embodiments, the reflective imaging portion 5 includes an imaging plate or a windshield.

[0086] In the related art, the windshield is usually used as the reflective imaging part 5. When the windshield is damaged, the head-up display system cannot be used normally. Before replacing the windshield, if the head-up display system is to be used, the imaging optical path needs to be redesigned.

[0087] The head-up display system provided in this embodiment can form a first virtual image 6 and a second virtual image 7 on different axes (that is, the line connecting the virtual image center of the first virtual image 6 and the center of the eye box area does not coincide with the line connecting the virtual image center of the second virtual image 7 and the center of the eye box area), and the imaging light path of the second virtual image does not pass through the reflective imaging part 5 (that is, the windshield), which reduces the dependence of the virtual image on the windshield. When the windshield is damaged, the second virtual image 7 can be used to display important information to ensure that the basic functions of the head-up display system can still be used normally.

[0088] Among them, the head-up display system also includes all components known to those skilled in the art, such as a transflective film arranged in the reflective imaging part 5, which is used to increase the reflectivity of the image light with the first polarization characteristic to increase the brightness of the first virtual image 6, which is not limited here.

[0089] On the basis of the above-mentioned implementation manner, the embodiment of the present disclosure further provides a means of transportation, including: any one of the above-mentioned head-up display systems, which has corresponding beneficial effects, and will not be described again here to avoid repeated description.

[0090] Among them, transportation vehicles include but are not limited to land transportation vehicles such as vehicles, as well as air transportation vehicles such as aircraft, or water or underwater transportation vehicles.

[0091] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0092] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A head-up display, It is characterized in that include: An image generating unit, configured to alternately output a first image light and a second image light according to a preset timing; the first image light and the second image light have a first polarization characteristic; a polarization conversion unit, located in the outgoing light path of the image generating unit; the polarization conversion unit is used to convert the polarization characteristic of one of the first image light and the second image light into a second polarization characteristic based on the preset timing; The polarization transflection section is located in the output light path of the polarization conversion section; the polarization transflection section is used to reflect image light with a first polarization characteristic, and the image light reflected by the polarization transflection section is used to form a first virtual image; the polarization transflection section is also used to transmit image light with a second polarization characteristic, and the image light transmitted by the polarization transflection section is used to form a second virtual image.

2. The head-up display according to claim 1, It is characterized in that A line connecting the virtual image center of the first virtual image and the center of the eye box area does not coincide with a line connecting the virtual image center of the second virtual image and the center of the eye box area.

3. The head-up display according to claim 1, It is characterized in that The polarization conversion unit includes an electrically controlled liquid crystal polarization element; the head-up display further includes: a first control module; The first control module is used to control the on and off of the electrically-controlled liquid crystal polarization element based on the preset timing; wherein the electrically-controlled liquid crystal polarization element converts the polarization characteristics of one of the first image light and the second image light into a second polarization characteristic when powered on, and the electrically-controlled liquid crystal polarization element does not change the polarization characteristics of the first image light and the second image light when powered off.

4. The head-up display according to claim 3, It is characterized in that The electrically controlled liquid crystal polarization element comprises an incident surface, an exit surface and a liquid crystal box, wherein the liquid crystal box is located between the incident surface and the exit surface; Among them, when the electrically-controlled liquid crystal polarization element is powered off, the liquid crystal molecules in the liquid crystal box remain in the first direction and do not change the polarization characteristics of the image light incident from the incident surface; when the electrically-controlled liquid crystal polarization element is powered on, the liquid crystal molecules in the liquid crystal box rotate from the first direction to the second direction, converting the polarization characteristics of the image light incident from the incident surface into the second polarization characteristics.

5. The head-up display according to claim 1, It is characterized in that The polarization conversion unit includes a movable polarization conversion element; the head-up display further includes: a second control module; The second control module is used to control the movable polarization conversion element to switch between a first position and a second position based on the preset timing; wherein, when the movable polarization conversion element is located at the first position, the movable polarization conversion element is in the output light path of the image generating unit, and converts the polarization characteristics of the image light output by the image generating unit into the second polarization characteristics; when the movable polarization conversion element is located at the second position, the movable polarization conversion element is not in the output light path of the image generating unit, and does not change the polarization characteristics of the image light output by the image generating unit.

6. The head-up display according to claim 1, It is characterized in that The image light with the first polarization characteristic is horizontal linear polarization light, and the image light with the second polarization characteristic is vertical linear polarization light, and the polarization transflective portion is used to reflect the horizontal linear polarization light and transmit the vertical linear polarization light; or, The image light with the first polarization characteristic is vertical linear polarized light, and the image light with the second polarization characteristic is horizontal linear polarized light. The polarization transflective portion is used to reflect the vertical linear polarized light and transmit the horizontal linear polarized light.

7. The head-up display according to claim 1, It is characterized in that Also includes: a reflective element, located in the optical path between the image generating unit and the polarized transflective portion, and configured to reflect the first image light and the second image light output by the image generating unit to the polarized transflective portion; The polarization conversion section is located in the light path between the image generation unit and the reflective element, or in the light path between the reflective element and the polarization transflective section.

8. The head-up display according to claim 7, It is characterized in that The reflective element includes a plane reflector, or a first curved reflector, or a plane reflector and a first curved reflector.

9. The head-up display according to any one of claims 1 to 8, It is characterized in that Also includes: A second curved reflector is located in the reflective light path of the polarized reflective portion, and the image light reflected by the second curved reflector is used to form a first virtual image; In the imaging optical path of the second virtual image, the image light output by the image generating unit for forming the second virtual image does not pass through the second curved reflector.

10. A head-up display system, It is characterized in that include: A reflective imaging unit and a head-up display as claimed in any one of claims 1 to 9; The reflective imaging part is located in the reflective light path of the polarized transflective part, and is used to reflect the image light reflected by the polarized transflective part to the eye box area to form a first virtual image.

11. The head-up display system according to claim 10, It is characterized in that In the imaging optical path of the second virtual image, the image light output by the image generating unit for forming the second virtual image does not pass through the reflective imaging portion.

12. A means of transportation, It is characterized in that include: A head-up display system as claimed in claim 10 or 11.

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