TWI739644B - Augmented reality head up display - Google Patents

Abstract

An augmented reality head up display includes a display device and a light path mirror assembly with an electronically controlled liquid crystal polarization plate. By switching a power-on state and a power-off state of the electronically controlled liquid crystal polarization plate, the light path of a light provided from the display device is changed, so that a plurality of images provided by the display device forms a plurality of virtual images in different positions. Consequently, the user can see the plurality of virtual images at the same time.

Description

Augmented reality head-up display

The present invention relates to an augmented reality head up display (HUD), in particular to an augmented reality (AR) head up display.

The head-up display is a kind of flight aid instrument commonly used in aircraft. The head-up display can project flight information to the front of the windshield, so the pilot can see the flight information without lowering his head, avoiding interruption of attention and improving safety. Because of the convenience of a head-up display and its ability to improve safety, some automakers have also begun to install a head-up display in their cars. The head-up display can project the car's speed, rotation speed, navigation and other information to the front of the windshield, so the driver's vision can get car information without looking down, which improves driving safety. In order to combine images with real road conditions, augmented reality head-up displays have become a popular research direction.

In order to achieve the augmented reality effect, the current augmented reality head-up display requires two or more display devices to provide multiple images, thereby forming multiple virtual images at the far end and the near end. However, more display devices will not only increase the volume of the augmented reality head-up display, but also increase the cost of the augmented reality head-up display.

The purpose of the present invention is to provide an augmented reality head-up display, which uses one display device to form multiple virtual images at multiple locations.

According to the present invention, an augmented reality head-up display includes a display device and a light path Mirror group. The display device emits a light, and the optical path mirror group is arranged on an optical path of the light. The optical path mirror group includes an electrically controlled liquid crystal polarizer and a reflecting mirror. The electrically controlled liquid crystal polarizer is arranged on the light path. The reflecting mirror is arranged on the light path and located between the electrically controlled liquid crystal polarizer and the display device, and reflects the light from the display device to the electrically controlled liquid crystal polarizer. In a first period of time, the electrically controlled liquid crystal polarizer reflects the light from the mirror to form a first virtual image at a first position. In a second time period, the light from the reflector penetrates the electrically controlled liquid crystal polarizer to form a second virtual image at a second position.

According to the present invention, an augmented reality head-up display includes a display device and an optical path mirror group. The display device emits a light, and the optical path mirror group is arranged on an optical path of the light. The optical path mirror group includes an electrically controlled liquid crystal polarizer and a reflecting mirror. The electrically controlled liquid crystal polarizer and the reflecting mirror are both arranged on the light path, and the electrically controlled liquid crystal polarizer is located between the reflecting mirror and the display device. In a first period of time, the electrically controlled liquid crystal polarizer reflects light from the display device, and the reflector reflects the light from the electrically controlled liquid crystal polarizer to form a first virtual image at a first position. In a second time period, the light from the display device penetrates the electrically controlled liquid crystal polarizer to form a second virtual image at a second position.

According to the present invention, an augmented reality head-up display includes a display device and an optical path mirror group. The display device emits a light, and the optical path mirror group is arranged on an optical path of the light. The optical path mirror group includes a first electrically controlled liquid crystal polarizer and a second electrically controlled liquid crystal polarizer. The first electrically controlled liquid crystal polarizer and the second electrically controlled liquid crystal polarizer are both on the light path, and the second electrically controlled liquid crystal polarizer is located between the first electrically controlled liquid crystal polarizer and the display device. In a first period, the first electrically controlled liquid crystal polarizer reflects the light from the display device, and the second electrically controlled liquid crystal polarizer reflects the light from the first electrically controlled liquid crystal polarizer to a first The position forms a first virtual image. In a second time period, the first electrically controlled liquid crystal polarizer reflects the light from the display device, and the light from the first electrically controlled liquid crystal polarizer penetrates the second electrically controlled liquid crystal polarizer to form a first Two positions form a second virtual picture. In a third period, the light from the display device penetrates the first electrically controlled liquid crystal polarizer to form a third virtual image at a third position.

The augmented reality head-up display of the present invention only needs one display device to generate multiple virtual images in multiple positions. Therefore, the augmented reality head-up display of the present invention has a small volume and a low cost.

10: Augmented reality head-up display

12: display device

14: Optical path mirror group

16: reflector

18: Electronically controlled liquid crystal polarizer

182: Polarization rotator

1822: incident surface

1824: exit surface

1826: LCD box

184: reflective polarizer

20: Human Eye

22: Windshield

30: Augmented reality head-up display

32: display device

34: Optical path mirror group

36: Electronically controlled liquid crystal polarizer

362: Polarization Rotator

364: reflective polarizer

38: Mirror

40: Augmented reality head-up display

42: display device

44: Optical path mirror group

46: The first electronically controlled liquid crystal polarizer

462: Polarization Rotator

464: reflective polarizer

48: The second electrically controlled liquid crystal polarizer

482: Polarization Rotator

484: reflective polarizer

A: The first virtual image

A’: Image

B: The second virtual image

B’: Image

C: The third virtual image

C’: Image

L1: light

LP: Polarization direction

LS: Polarization direction

RPP: Optical axis

Fig. 1 shows the first embodiment of the augmented reality head-up display of the present invention.

Figure 2 shows an embodiment of an electrically controlled liquid crystal polarizer.

Figure 3 shows an embodiment when the electrically controlled liquid crystal polarizer is not energized.

Figure 4 shows an embodiment when the electrically controlled liquid crystal polarizer is energized.

FIG. 5 shows an embodiment in which the display device in FIG. 1 outputs two different images.

Fig. 6 shows the second embodiment of the augmented reality head-up display of the present invention.

Fig. 7 shows a third embodiment of the augmented reality head-up display of the present invention.

FIG. 8 shows an embodiment in which the display device in FIG. 7 outputs three different images.

Fig. 1 shows the first embodiment of the augmented reality head-up display of the present invention. In FIG. 1, the augmented reality head-up display 10 includes a display device 12 and an optical path mirror group 14. The display device 12 is used for emitting light L1 to the optical path lens group 14 to form a first virtual image A or a second virtual image B in front of the windshield 22, where the light L1 can be an image, and the light L1 is an S-polarized light or a P polarized light. Generally speaking, the polarization direction LS of S-polarized light is the vertical direction, and the polarization direction LP of P-polarized light is the horizontal direction. The display device 12 may be, but is not limited to, a display or a projection device. The light path mirror group 14 is arranged on the light path. The light path mirror group 14 can change the light path to project the light L1 to different positions, and then form a first virtual image A at the first position in front of the windshield 22 or on the windshield The second position before 22 forms a second virtual image B. Optical path lens group 14 contains A mirror 16 and an electrically controlled liquid crystal polarizer 18. The reflecting mirror 16 and the electrically controlled liquid crystal polarizer 18 are both arranged on the light path, and the reflecting mirror 16 is located between the electrically controlled liquid crystal polarizer 18 and the display device 12. The mirror 16 reflects the light L1 from the display device 12. The light L1 reflected by the reflector 16 can pass through the electrically controlled liquid crystal polarizer 18 or be reflected by the electrically controlled liquid crystal polarizer 18.

FIG. 2 shows an embodiment of the electrically controlled liquid crystal polarizer 18. The electrically controlled liquid crystal polarizer 18 includes a polarization rotator 182 and a reflective polarizer 184. The polarization rotator 182 has an entrance surface 1822, an exit surface 1824, and a liquid crystal cell 1826. The liquid crystal cell 1826 is sandwiched between the entrance surface 1822 and the exit surface 1824. Electrodes are provided on the entrance surface 1822 and the exit surface 1824. The electrodes can be, but not limited to, indium tin oxide transparent electrodes, external control voltage modules (not shown) Applying a voltage to the electrodes causes the liquid crystal molecules in the liquid crystal cell 1826 to rotate to a predetermined alignment direction, thereby switching the state in which the electrically controlled liquid crystal polarizer can pass or reflect polarized light. The reflective polarizer 184 is disposed on the exit surface 1824 side of the polarization rotator 182 and is attached to the exit surface 1824, and the reflective polarizer 184 has an optical axis RPP. The reflective polarizer 184 is parallel to the polarization rotator 182. When the polarization direction of the light L1 emitted from the exit surface 1824 is parallel to the optical axis RPP of the reflective polarizer 184, the light L1 will pass through the reflective polarizer 184. When the polarization direction of the light L1 emitted from the exit surface 1824 is perpendicular to the optical axis RPP of the reflective polarizer 184, the light L1 will be reflected by the reflective polarizer 184.

In order to make it easier to understand, an embodiment is used to illustrate the non-energized state and the energized state of the electrically controlled liquid crystal polarizer 18. Assuming that the light L1 emitted by the display device 12 is P-polarized light and the optical axis RPP of the reflective polarizer 184 is in the horizontal direction, when the electrically controlled liquid crystal polarizer 18 is not energized, the liquid crystal molecules in the liquid crystal cell 1826 will not rotate. As shown in Figure 3, after the light L1 enters the liquid crystal cell 1826 from the incident surface 1824, the polarization direction LP of the light L1 will not be changed, so the polarization direction LP of the light L1 emitted from the exit surface 1824 is parallel to the reflective polarizer 184 The optical axis RPP can penetrate the reflective polarizer 184. In other words, when the electrically controlled liquid crystal polarizer 18 is not energized, the polarization direction LP of the light L1 emitted from the exit surface 1824 is parallel to the optical axis RPP of the reflective polarizer 184, so the light L1 emitted by the display device 12 can penetrate Electrically controlled liquid crystal polarizer 18. When the electrically controlled liquid crystal polarizer 18 is energized, the liquid crystal molecules in the liquid crystal cell 1826 are turned As shown in Figure 4, after the light L1 enters the liquid crystal cell 1826 from the incident surface 1824, the light L1 will change from P-polarized light to S-polarized light, that is, from the polarization direction LP to the polarization direction LS, so from the exit surface The polarization direction LS of the light L1 emitted by 1824 is perpendicular to the optical axis RPP of the reflective polarizer 184, which causes the reflective polarizer 184 to reflect the light L1 emitted from the exit surface 1824. In other words, when the electrically controlled liquid crystal polarizer 18 is energized, the polarization direction LS of the light L1 emitted from the exit surface 1824 is perpendicular to the optical axis RPP of the reflective polarizer 184, so the light L1 emitted by the display device 12 will be electrically controlled The liquid crystal polarizer 18 reflects.

In another embodiment, it is assumed that the optical axis RPP of the reflective polarizer 184 is still in the horizontal direction, but the light L1 emitted by the display device 12 is S-polarized light. When the electrically controlled liquid crystal polarizer 18 is not energized, the liquid crystal molecules in the liquid crystal cell 1826 will not rotate. After the light L1 enters the liquid crystal cell 1826 from the incident surface 1824, the polarization direction LS of the light L1 will not be changed. The polarization direction LS of the light L1 emitted from the exit surface 1824 is perpendicular to the optical axis RPP of the reflective polarizer 184, which causes the reflective polarizer 184 to reflect the light L1 emitted from the exit surface 1824. In other words, when the electrically controlled liquid crystal polarizer 18 is not energized, the polarization direction LS of the light L1 emitted from the exit surface 1824 is perpendicular to the optical axis RPP of the reflective polarizer 184, so the light L1 emitted by the display device 12 will be electrically charged. Control the reflection of the liquid crystal polarizer 18. When the electrically controlled liquid crystal polarizer 18 is energized, the liquid crystal molecules in the liquid crystal cell 1826 are rotated. After the light L1 enters the liquid crystal cell 1826 from the incident surface 1824, the light L1 will change from S-polarized light to P-polarized light, so from the exit surface The polarization direction LP of the light L1 emitted by 1824 is parallel to the optical axis RPP of the reflective polarizer 184, and the light L1 emitted from the exit surface 1824 will pass through the reflective polarizer 184. In other words, when the electrically controlled liquid crystal polarizer 18 is energized, the polarization direction LP of the light L1 emitted from the exit surface 1824 is parallel to the optical axis RPP of the reflective polarizer 184, so the light L1 emitted by the display device 12 can penetrate the electricity.控LCD polarizer 18.

As described in the above two embodiments, the non-energized state and the energized state of the electrically controlled liquid crystal polarizer 18 can change the light path of the light L1. By changing the light path of the light L1 by the electrically controlled liquid crystal polarizer 18, the present invention enables the display device 12 The provided images are projected at different locations near and far. The above two embodiments are to explain why the electrically controlled liquid crystal polarizer 18 can change the path of the light L1 when it is not energized and when it is energized. The present invention does not Limited to the above two embodiments, for example, in other embodiments, the optical axis RPP of the reflective polarizer 184 may also be in the vertical direction.

Next, it will be described how the augmented reality head-up display 10 in FIG. 1 forms two virtual images A and B. 1 to 5, in the first time period T1, the display device 12 outputs an image A'. At this time, the light L1 emitted by the display device 12 is reflected by the mirror 16 to the electrically controlled liquid crystal polarizer 18. It is assumed that the light L1 emitted by the display device 12 is P-polarized light, the optical axis RPP of the reflective polarizer 184 is in the horizontal direction, and the electrically controlled liquid crystal polarizer 18 is energized at time T1. As shown in FIG. 4, applying a voltage to the liquid crystal cell 1826 through an external control voltage module (not shown) causes the liquid crystal molecules in the liquid crystal cell 1826 to rotate to a predetermined alignment direction, for example, the polarization direction LS. Therefore, the polarization rotator The polarization direction LP of the light L1 entering the incident surface 1822 of the 182 will be changed to the polarization direction LS by the liquid crystal cell 1826. Since the polarization direction LS is perpendicular to the optical axis RPP of the reflective polarizer 184, the light L1 emitted from the exit surface 1824 is reflected by the reflective polarizer 184 to the windshield 22. Finally, the light L1 is reflected by the windshield 22 to the human eye 20, and the user can see that the first virtual image A is located at a first position in front of the windshield 22. Simply put, in the first time period T1, the optical path mirror group 14 switches the electrically controlled liquid crystal polarizer 18 to the energized state, so as to switch the optical path of the light L1 to the first sub-light path, which is from the display device 12 reaches the human eye 20 through the mirror 16, the electrically controlled liquid crystal polarizer 18, and the windshield 22 in sequence. The first virtual image A is located far in front of the windshield 22, so the first virtual image A may be, but not limited to, navigation path information.

In the second time period T2 in FIG. 5, the display device 12 outputs the image B'. At this time, the light L1 emitted by the display device 12 is also reflected by the mirror 16 to the electrically controlled liquid crystal polarizer 18. Since the electrically controlled liquid crystal polarizer 18 is not energized at the time T2, the liquid crystal molecules in the liquid crystal cell 1826 are not rotated, as shown in FIG. 3. The polarization direction LP of the light L1 entering from the incident surface 1822 of the polarization rotator 182 will not be changed. Since the polarization direction LP is parallel to the optical axis RPP of the reflective polarizer 184, the light L1 emitted from the exit surface 1824 will penetrate the reflective polarizer 184 and be projected to the human eye 20, and the user can see that the second virtual image B is located at In a second position in front of the windshield 22. Simply put, in the second time period T2, the optical path mirror group 14 will be electrically controlled The liquid crystal polarizer 18 is switched to a non-energized state to switch the optical path of the light L1 to a second sub-light path. The second sub-path goes from the display device 12 through the mirror 16 and the electrically controlled liquid crystal polarizer 18 to the human eye in sequence 20. The first position is farther than the second position, that is, the distance between the first position and the windshield 22 is greater than the distance between the second position and the windshield 22. The second virtual image B is located closer to the front of the windshield 22, so the second virtual image B can be, but is not limited to, vehicle speed information.

When the human eye views an object, the image of the object will be imaged on the retina and input into the human brain by the optic nerve, so that people can feel the image of the object. When the object is removed, the impression of the optic nerve on the object will not disappear immediately, and the human eye can still retain the image for about 0.1-0.4 seconds. This phenomenon is called persistence of vision. The present invention utilizes this visual persistence feature to allow human eyes to see the first virtual image A and the second virtual image B at the same time, thereby achieving a display device 12 that simultaneously displays multiple images. Therefore, the display device 12 in FIG. 1 repeatedly outputs the image A'and the image B', and the time interval between the two images A'(ie the second period T2) and the time interval between the two images B'(ie the first period T1) ) Are less than or equal to 0.1 seconds. In other words, the frame rate of the image A'and the image B'(or the frame rate of the first virtual image A and the second virtual image B) is greater than or equal to 10 fps.

Fig. 6 shows the second embodiment of the augmented reality head-up display of the present invention. In FIG. 6, the augmented reality head-up display 30 includes a display device 32 and an optical path mirror group 34. The display device 32 is used for emitting light L1 to the optical path lens group 34 to form a first virtual image A or a second virtual image B in front of the windshield 22, where the light L1 can be an image, and the light L1 is an S-polarized light or a P polarized light. Generally speaking, the polarization direction LS of S-polarized light is the vertical direction, and the polarization direction LP of P-polarized light is the horizontal direction. The display device 32 may be, but is not limited to, a display or a projection device. The light path mirror group 34 is arranged on a light path of the light L1. The light path mirror group 34 can change the light path to project the light L1 to different positions, and then form a first virtual image A at the first position in front of the windshield 22 or The second position in front of the windshield 22 forms a second virtual image B. The optical path mirror group 34 includes an electrically controlled liquid crystal polarizer 36 and a reflecting mirror 38. The electrically controlled liquid crystal polarizer 36 and the mirror 38 are both arranged on the light path, and the electrically controlled liquid crystal polarizer 36 is located between the mirror 38 and the display device 32. The light L1 from the display device 32 can pass through the electrically controlled liquid crystal polarizer 36 or be reversed by the electrically controlled liquid crystal polarizer 36. The reflecting mirror 38 reflects the light L1 from the electrically controlled liquid crystal polarizer 36. The electrically controlled liquid crystal polarizer 36 includes a polarization rotator 362 and a reflective polarizer 364, and the reflective polarizer 364 is attached to the exit surface of the polarization rotator 362. The structure and operating principle of the electrically controlled liquid crystal polarizer 36 can be referred to FIG. 2, FIG. 3, and FIG. 4, and will not be repeated here.

3 and 6, in the first time period T1, the display device 32 outputs the image A'. Assuming that the light L1 emitted by the display device 32 is P-polarized light, the optical axis RPP of the reflective polarizer 364 is in the horizontal direction, and the electrically controlled liquid crystal polarizer 36 is energized at time T1. As shown in FIG. 4, after the polarization rotator 362 is energized, the liquid crystal molecules of the liquid crystal cell of the polarization rotator 362 are rotated, so the light L1 entering from the incident surface of the polarization rotator 362 (incident surface 1822 in FIG. 4) The polarization direction LP will be changed to the polarization direction LS. Since the polarization direction LS is perpendicular to the optical axis RPP of the reflective polarizer 364, the light L1 emitted from the exit surface of the polarization rotator 362 (the exit surface 1824 in FIG. 4) is reflected by the reflective polarizer 364 to the mirror 38. The mirror 38 then reflects the light L1 from the electrically controlled liquid crystal polarizer 36 to the windshield 22. Finally, the light L1 is reflected by the windshield 22 to the human eye 20, and the user can see that the first virtual image A is located at a first position in front of the windshield 22. To put it simply, in the first time period T1, the optical path mirror group 34 switches the electrically controlled liquid crystal polarizer 36 to the energized state, so as to switch the optical path of the light L1 to the first sub-light path from the display device 32 sequentially passes through the electrically controlled liquid crystal polarizer 36, the reflector 38, and the windshield 22 to reach the human eye 20. The first virtual image A is located far in front of the windshield 22, so the first virtual image A may be, but not limited to, navigation path information.

In the second time period T2, the display device 32 outputs the image B', and the electrically controlled liquid crystal polarizer 36 is not energized. Since the polarization rotator 362 of the electrically controlled liquid crystal polarizer 36 is not energized, the liquid crystal molecules of the liquid crystal cell of the polarization rotator 362 are not rotated. The polarization direction LP of the light L1 entering from the incident surface of the polarization rotator 362 (such as the incident surface 1822 in FIG. 3) will not be changed. The polarization direction LP is parallel to the optical axis RPP of the reflective polarizer 184, so the light L1 emitted from the exit surface (exit surface 1824 in FIG. 3) will pass through the reflective polarizer 364 and be projected to the windshield 22. Finally, the windshield 22 reflects the light L1 to the human eye 20, The user can thus see that the second virtual image B is located at a second position in front of the windshield 22. To put it simply, in the second time period T2, the optical path mirror group 34 switches the electrically controlled liquid crystal polarizer 36 to the non-energized state, so as to switch the optical path of the light L1 to the second sub-optical path, which is changed from the display The device 32 reaches the human eye 20 through the electrically controlled liquid crystal polarizer 36 and the windshield 22 in sequence. The first position is farther than the second position, that is, the distance between the first position and the windshield 22 is greater than the distance between the second position and the windshield 22. The second virtual image B is located closer to the front of the windshield 22, so the second virtual image B can be, but is not limited to, vehicle speed information.

The display device 32 in FIG. 6 repeatedly outputs the image A'and the image B', and the time interval between the two images A'(ie the second time period T2) and the time interval between the two images B'(ie the first time period T1) Both are less than or equal to 0.1 seconds. In other words, the frame rate of the image A'and the image B'(or the frame rate of the first virtual image A and the second virtual image B) is greater than or equal to 10 fps. According to the visual persistence characteristics, the augmented reality head-up display 30 of FIG. 6 can allow the user to see the first virtual image A and the second virtual image B at the same time, thereby achieving a display device 32 to display multiple images at the same time.

Fig. 7 shows a third embodiment of the augmented reality head-up display of the present invention. In FIG. 7, the augmented reality head-up display 40 includes a display device 42 and an optical path mirror group 44. The display device 42 is used for emitting light L1 to the optical path lens group 44 to form a first virtual image A, a second virtual image B, or a third virtual image C in front of the windshield 22, where the light L1 can be an image, and the light L1 is a S polarized light or one P polarized light. Generally speaking, the polarization direction LS of S-polarized light is the vertical direction, and the polarization direction LP of P-polarized light is the horizontal direction. The display device 42 may be, but is not limited to, a display or a projection device. The light path mirror group 44 is arranged on the light path of the light L1, and the light path mirror group 44 can change the light path. In order to project the light L1 to different positions, the first virtual image A is formed at the first position in front of the windshield 22, the second virtual image B is formed at the second position in front of the windshield 22, or the first virtual image B is formed in front of the windshield 22. Three positions form a third virtual image C. The optical path mirror group 44 includes a first electrically controlled liquid crystal polarizer 46 and a second electrically controlled liquid crystal polarizer 48. The first electrically controlled liquid crystal polarizer 46 and the second electrically controlled liquid crystal polarizer 48 are both arranged on the light path, and the second electrically controlled liquid crystal polarizer 48 is located between the first electrically controlled liquid crystal polarizer 46 and the display device 42. The light L1 from the display device 42 can penetrate the electronically controlled liquid crystal The polarizer 46 may be reflected by the electrically controlled liquid crystal polarizer 46. The light L1 from the electrically controlled liquid crystal polarizer 46 can pass through the electrically controlled liquid crystal polarizer 48 or be reflected by the electrically controlled liquid crystal polarizer 48. The first electrically controlled liquid crystal polarizer 46 includes a polarization rotator 462 and a reflective polarizer 464. The reflective polarizer 464 is attached to the exit surface of the polarization rotator 462. The second electrically controlled liquid crystal polarizer 48 includes a polarization rotator 482 and a reflective polarizer 484, and the reflective polarizer 484 is attached to the exit surface of the polarization rotator 482. The structure and operation principle of the first electrically controlled liquid crystal polarizer 46 and the second electrically controlled liquid crystal polarizer 48 can be referred to FIG. 2, FIG. 3, and FIG. 4, which will not be repeated here.

FIG. 8 shows an embodiment in which the display device 42 in FIG. 7 outputs three different images, and the display device 12 sequentially outputs image A', image B', and image C'. 7 and 8, in the first time period T1, the display device 42 outputs the image A'. It is assumed that the light L1 emitted by the display device 42 is P-polarized light, and the first electrically controlled liquid crystal polarizer 46 and the second electrically controlled liquid crystal polarizer 48 are energized at time T1. As shown in FIG. 4, after the polarization rotator 462 of the first electrically controlled liquid crystal polarizer 46 is energized, the liquid crystal molecules of the liquid crystal cell of the polarization rotator 462 are rotated, so from the incident surface of the polarization rotator 462 (as shown in FIG. 4) The polarization direction LP of the light L1 entering the incident surface 1822) will be changed to the polarization direction LS. Since the polarization direction LS is perpendicular to the optical axis RPP of the reflective polarizer 464, the light L1 emitted from the exit surface of the polarization rotator 462 (the exit surface 1824 in FIG. 4) is reflected by the reflective polarizer 464 to the second electronic control panel. Liquid crystal polarizer 48. Because the polarization rotator 482 of the second electrically controlled liquid crystal polarizer 48 is also energized, the liquid crystal molecules of the liquid crystal cell of the polarization rotator 482 are rotated and enter from the incident surface of the polarization rotator 482 (the incident surface 1822 in FIG. 4). The polarization direction LP of the light L1 will be changed to the polarization direction LS. Since the polarization direction LS is perpendicular to the optical axis RPP of the reflective polarizer 484, the light L1 emitted from the exit surface of the polarization rotator 482 (the exit surface 1824 in FIG. 4) is reflected by the reflective polarizer 484 to the windshield twenty two. Finally, the light L1 is reflected by the windshield 22 to the human eye 20, and the user can see that the first virtual image A is located at a first position in front of the windshield 22. Simply put, in the first time period T1, the optical path mirror group 44 switches the first electrically controlled liquid crystal polarizer 46 and the second electrically controlled liquid crystal polarizer 48 to the energized state, so as to switch the optical path of the light L1 to the first sub Light path, the first sub-path passes through the display device 42 sequentially The first electrically controlled liquid crystal polarizer 46, the second electrically controlled liquid crystal polarizer 48 and the windshield 22 reach the human eye 20 afterwards.

In the second period T2, the display device 42 outputs the image B'. Assume that during the second time period T2, the first electrically controlled liquid crystal polarizer 46 is energized, but the second electrically controlled liquid crystal polarizer 48 is not energized. As mentioned above, the first electrically controlled liquid crystal polarizer 46 that is energized will reflect the light L1 from the display device 42 to the second electrically controlled liquid crystal polarizer 48. Since the polarization rotator 482 of the second electrically controlled liquid crystal polarizer 48 is not energized, the polarization direction LP of the light L1 entering from the incident surface of the polarization rotator 482 (such as the incident surface 1822 in FIG. 3) will not be changed. The polarization direction LP is parallel to the optical axis RPP of the reflective polarizer 484, so the light L1 emitted from the exit surface of the polarization rotator 482 (the exit surface 1824 in FIG. 3) will penetrate the reflective polarizer 484 and be projected to the human eye 20. Therefore, the user can see that the second virtual image B is located at a second position in front of the windshield 22. To put it simply, in the second time period T2, the optical path lens group 44 switches the first electrically controlled liquid crystal polarizer 46 to the energized state and the second electrically controlled liquid crystal polarizer 48 to the non-energized state, so as to reduce the light of the light L1. The path is switched to a second sub-light path, which goes from the display device 42 to the human eye 20 through the first electrically controlled liquid crystal polarizer 46 and the second electrically controlled liquid crystal polarizer 48 in sequence.

In the third period T3, the display device 42 outputs the image C'. It is assumed that during the third time period T3, the first electrically controlled liquid crystal polarizer 46 and the second electrically controlled liquid crystal polarizer 48 are not energized. Since the polarization rotator 462 of the first electrically controlled liquid crystal polarizer 46 is not energized, the polarization direction LP of the light L1 entering from the incident surface of the polarization rotator 462 (incident surface 1822 in FIG. 3) will not be changed. The polarization direction LP is parallel to the optical axis RPP of the reflective polarizer 464, so the light L1 emitted from the exit surface of the polarization rotator 462 (the exit surface 1824 in FIG. 3) will penetrate the reflective polarizer 464 and be projected to the windshield Glass 22. Finally, the windshield 22 reflects the light L1 to the human eye 20 so that the user can see that the third virtual image C is located at a third position in front of the windshield 22. To put it simply, in the third time period T3, the optical path mirror group 44 switches the first electrically controlled liquid crystal polarizer 46 and the second electrically controlled liquid crystal polarizer 48 to the non-energized state, so as to switch the optical path of the light L1 to the third A sub-light path, the third sub-path from the display device 42 to the human eye 20 through the first electrically controlled liquid crystal polarizer 46 and the windshield 22 in sequence. The first position is farther than the third position, and the third position is farther than the second position. In other words, the distance between the first position and the windshield 22 is greater than the distance between the third position and the windshield 22, and the distance between the third position and the windshield 22 is greater than the distance between the second position and the windshield 22.

The display device 42 in FIG. 7 repeatedly outputs image A', image B', and image C', and the time interval between two images A'(ie T2+T3) and the time interval between two images B'(ie T1+ T3) and the time interval between the two images C′ (ie, T1+T2) are both less than or equal to 0.1 second. In other words, the frame rate of the image A', the image B', and the image C'(or the frame rate of the first virtual image A, the second virtual image B, and the third virtual image C) is greater than or equal to 10 fps. According to the visual persistence characteristic, the augmented reality head-up display 40 of FIG. 7 can allow the user to see the first virtual image A, the second virtual image B, and the third virtual image C at the same time, thereby achieving a display device 42 that simultaneously displays multiple images.

The above are only the embodiments of the present invention and do not limit the present invention in any form. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field, Without departing from the scope of the technical solution of the present invention, when the technical content disclosed above can be used to make slight changes or modification into equivalent embodiments with equivalent changes, but any content that does not depart from the technical solution of the present invention is based on the technical essence of the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

10: Augmented reality head-up display

12: display device

14: Optical path mirror group

16: reflector

18: Electronically controlled liquid crystal polarizer

182: Polarization rotator

184: reflective polarizer

20: Human Eye

22: Windshield

A: The first virtual image

B: The second virtual image

L1: light

Claims (16)

An augmented reality head-up display, comprising: a display device for emitting a light; and an optical path mirror group arranged on a light path of the light, including an electrically controlled liquid crystal polarizer arranged on the light path: wherein, The electrically controlled liquid crystal polarizer includes: a polarization rotator having an entrance surface and an exit surface, wherein when the polarization rotator is energized, the polarization rotator changes the polarization direction of the light entering from the entrance surface; and A reflective polarizer is disposed on the exit surface, and the reflective polarizer has an optical axis, wherein when the polarization direction of the light emitted from the exit surface is parallel to the optical axis, the light emitted from the exit surface The light penetrates the reflective polarizer, and when the polarization direction of the light emitted from the exit surface is perpendicular to the optical axis, the reflective polarizer reflects the light emitted from the exit surface; wherein, the reflective polarizer The polarizer is parallel to the polarization rotator; wherein, in a first period, the electrically controlled liquid crystal polarizer reflects the light to form a first virtual image in a first position; wherein, in a second period, the light penetrates The electrically controlled liquid crystal polarizer forms a second virtual image at a second position. For example, the augmented reality head-up display of claim 1, wherein the optical path mirror group further includes a reflector disposed on the optical path and located between the electronically controlled liquid crystal polarizer and the display device, and the reflector is used to transmit data from the The light from the display device is reflected to the electrically controlled liquid crystal polarizer. For example, the augmented reality head-up display of claim 1, wherein the optical path lens group further includes a mirror The reflecting mirror is arranged on the light path, and the electrically controlled liquid crystal polarizer is located between the reflecting mirror and the display device, wherein in the first period of time, the reflecting mirror reflects the light from the electrically controlled liquid crystal polarizer to The first virtual image is formed at the first position. For example, the augmented reality head-up display of claim 1, wherein the display device is a display or a projection device. For example, the augmented reality head-up display of claim 1, wherein the light emitted by the display device is an S-polarized light or a P-polarized light. For example, the augmented reality head-up display of claim 1, wherein the frame rate of the first virtual image and the second virtual image is greater than or equal to 10 fps. For example, the augmented reality head-up display of claim 1, wherein the first position is farther than the second position. Such as the augmented reality head-up display of claim 1, wherein the light path includes a first sub-light path and a second sub-light path, and the light path lens group switches the energized state and the non-energized state of the electrically controlled liquid crystal polarizer to In the first time period, the light path is switched to the first sub-light path to form the first virtual image, and in the second time period the light path is switched to the second sub-light path to form the second virtual image. An augmented reality head-up display, including: a display device for emitting a light; and a light path mirror group, arranged on a light path of the light, including: a first electrically controlled liquid crystal polarizer, arranged on the light path On; and a second electrically controlled liquid crystal polarizer disposed on the light path and located between the first electrically controlled liquid crystal polarizer and the display device; wherein, in a first period of time, the first electrically controlled liquid crystal polarizer The sheet reflects the light from the display device, and the second electrically controlled liquid crystal polarizer reflects from the first electrically controlled liquid crystal polarizer The light of the vibrating plate forms a first virtual image at a first position; wherein, in a second period of time, the first electrically controlled liquid crystal polarizer reflects the light from the display device and comes from the first electrically controlled liquid crystal The light of the polarizer penetrates the second electrically controlled liquid crystal polarizer to form a second virtual image at a second position; wherein, in a third period of time, the light from the display device penetrates the first electrically controlled liquid crystal The polarizer forms a third virtual image at a third position. For example, the augmented reality head-up display of claim 9, wherein the first electrically controlled liquid crystal polarizer includes: a polarization rotator having an incident surface and an exit surface, wherein the light from the display device is incident on the incident surface, and When the polarization rotator is energized, the polarization rotator changes the polarization direction of the light entering from the incident surface; and a reflective polarizer is disposed on the exit surface, and the reflective polarizer has an optical axis, Wherein when the polarization direction of the light emitted from the exit surface is parallel to the optical axis, the light emitted from the exit surface penetrates the reflective polarizer, and when the polarization direction of the light emitted from the exit surface is When perpendicular to the optical axis, the reflective polarizer reflects the light emitted from the exit surface. For example, the augmented reality head-up display of claim 9, wherein the second electrically controlled liquid crystal polarizer includes: a polarization rotator having an incident surface and an exit surface, wherein the light from the first electrically controlled liquid crystal polarizer is incident on The incident surface, and when the polarization rotator is energized, the polarization rotator changes the polarization direction of the light entering from the incident surface; and a reflective polarizer is disposed on the exit surface, and the reflective polarizer Has an optical axis, wherein when the polarization direction of the light emitted from the exit surface is parallel to the optical axis, The light emitted from the exit surface penetrates the reflective polarizer, and when the polarization direction of the light emitted from the exit surface is perpendicular to the optical axis, the reflective polarizer reflects the light emitted from the exit surface . For example, the augmented reality head-up display of claim 9, wherein the display device is a display or a projection device. For example, the augmented reality head-up display of claim 9, wherein the light emitted by the display device is an S-polarized light or a P-polarized light. For example, the augmented reality head-up display of claim 9, wherein the frame rate of the first virtual image, the second virtual image, and the third virtual image is greater than or equal to 10 fps. Such as the augmented reality head-up display of claim 9, wherein the first position is farther than the third position, and the third position is farther than the second position. For example, the augmented reality head-up display of claim 9, wherein the light path includes a first sub-light path, a second sub-light path, and a second sub-light path, and the light path mirror group switches the first electronically controlled liquid crystal polarizer and The energized state and the non-energized state of the second electrically controlled liquid crystal polarizer to switch the light path to the first sub-light path during the first time period to form the first virtual image, and the light path during the second time period Switching to the second sub-light path to form the second virtual image, and switching the light path to the third sub-light path during the third time period to form the third virtual image.

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