CN114089532A

CN114089532A - Display system

Info

Publication number: CN114089532A
Application number: CN202111384530.7A
Authority: CN
Inventors: 孙宜嶙; 黄达人; 王祖铠
Original assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; Yecheng Optoelectronics Wuxi Co Ltd; General Interface Solution Ltd
Current assignee: Interface Optoelectronics Shenzhen Co Ltd; Interface Technology Chengdu Co Ltd; General Interface Solution Ltd
Priority date: 2021-11-19
Filing date: 2021-11-19
Publication date: 2022-02-25
Also published as: TW202321773A; TWI803068B

Abstract

A display system includes a light source module, an imaging module, a curved mirror and an optical module. The light source module is configured to project a first polarized image and a second polarized image, wherein the first polarized image has a first polarization state and the second polarized image has a second polarization state different from the first polarization state. The imaging module is configured to form a first real image from the first polarized image at a first position and form a second real image from the second polarized image at a second position. The optical module is arranged between the curved mirror and the imaging module and is configured to project the first real image and the second real image to the curved mirror simultaneously, so that the first real image and the second real image generate a first virtual image and a second virtual image with different depths of field in the curved mirror. The display system can generate two virtual images at the same time, so that the display system is beneficial to providing multi-view images in a short time. In addition, the display system can be configured to provide more images at the same scanning frequency.

Description

Display system

Technical Field

The present disclosure relates to a display system, and more particularly, to a head-up display (HUD) system.

Background

The head-up display can be mounted in a vehicle and can project required information at a front glass window of the vehicle, so that an observer can obtain the projected information while watching the front, and the safety of road driving is improved. In addition, with the head-up display, specific information can be displayed in the form of Augmented Reality (AR). Augmented reality is a technique of rendering a three-dimensional virtual object overlaid on the real world as seen by the naked eye of an observer. However, existing heads-up display systems can only display a virtual image in a single space at a single time. Therefore, there is still a need for improvement of the existing head-up display system.

Disclosure of Invention

One aspect of the present disclosure is a display system.

According to some embodiments of the present disclosure, a display system includes a light source module, an imaging module, a curved mirror, and an optical module. The light source module is configured to project a first polarized image and a second polarized image, wherein the first polarized image has a first polarization state, and the second polarized image has a second polarization state different from the first polarization state. The imaging module is configured to form a first real image from the first polarized image at a first position and form a second real image from the second polarized image at a second position. The optical module is arranged between the curved mirror and the imaging module, and the optical module is configured to project the first real image and the second real image to the curved mirror simultaneously, so that the first real image and the second real image generate a first virtual image and a second virtual image with different depths of field in the curved mirror.

In some embodiments of the present disclosure, the image forming module includes a first diffusion plate and a second diffusion plate. The first diffusion sheet is arranged between the light source module and the optical module, wherein the first polarized image is scattered after passing through the first diffusion sheet to form a first real image, and the second polarized image is not scattered after passing through the first diffusion sheet. The second diffusion sheet is arranged between the first diffusion sheet and the optical module, wherein the second polarized image is scattered after passing through the second diffusion sheet to form a second real image, and the first polarized image is not scattered after passing through the second polarizing sheet.

In some embodiments of the present disclosure, the first diffusion plate and the second diffusion plate have different liquid crystal axes.

In some embodiments of the present disclosure, the imaging module further includes a polarization modulation element. The polarization modulation element is arranged between the second diffusion sheet and the optical module, wherein when the polarization modulation element is closed, the polarization modulation element is used for converting the first polarization image into a third polarization image with a second polarization state, and when the polarization modulation element is opened, the polarization modulation element is used for allowing the first polarization image to pass through and keeping the first polarization state.

In some embodiments of the present disclosure, when the polarization modulation element is turned off, the imaging module further generates a third virtual image with a different depth of field from the first virtual image in the curved mirror.

In some embodiments of the present disclosure, the optical module includes a prism. The prism has a plurality of faces, a first face of which is capable of reflecting the first polarized image and passing the second polarized image.

In some embodiments of the present disclosure, the optical module further includes a mirror and a polarization element. The reflector is arranged on the second surface of the prism surface and is configured to reflect the second polarization image polarization element, and the reflector is arranged between the second surface of the prism and the reflector and is configured to reflect the second polarization image and eliminate the first polarization image incident to the polarization element.

In some embodiments of the present disclosure, the total number of facets of the prism is an even number.

In some embodiments of the present disclosure, the light source module includes a first light source set, a second light source set and a light modulator. The first light source set is configured to generate a first polarized light beam having a first polarization state. The second light source set is configured to generate a second polarized light beam having a second polarization state. The light modulator is used for modulating the first polarized light beam into a first polarized image and modulating the second polarized light beam into a second polarized image.

In some embodiments of the present disclosure, the display system further comprises a collimating lens. The collimating lens is arranged between the light source module and the imaging module and is configured to collimate the first polarized image and the second polarized image.

According to the embodiment of the disclosure, the display system comprises the light source module, the imaging module, the curved mirror and the optical module, so that two virtual images can be generated at the same time, thereby being beneficial to providing multi-view images in a short time and further improving the safety of an observer in road driving. In addition, the display system of some embodiments of the present disclosure may be configured to provide more images at the same scan frequency than a display that provides a single image at a single time.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the disclosure.

Drawings

Aspects of the present disclosure can be understood from the following detailed description of the embodiments and the accompanying drawings.

FIG. 1 illustrates a schematic diagram of a display system according to some embodiments of the present disclosure.

FIG. 2 is a schematic view of the light source module shown in FIG. 1.

FIG. 3 is a schematic diagram illustrating optical paths of the display system of FIG. 1 at a first timing according to some embodiments of the present disclosure.

FIG. 4 is a schematic diagram illustrating optical paths of the display system of FIG. 1 at a second timing according to some embodiments of the present disclosure.

FIG. 5A is a diagram illustrating the polarization modulation device of FIG. 1 in an operating state.

FIG. 5B is a diagram illustrating the polarization modulation device of FIG. 1 in another operating state.

Fig. 6-9 illustrate cross-sectional views of methods of manufacturing a diffuser plate at various steps according to some embodiments of the present disclosure.

FIG. 10A is a schematic diagram of the first diffusion plate of FIG. 1 in an operating state.

FIG. 10B is a schematic diagram of the first diffusion plate of FIG. 1 in another operation state.

FIG. 11A is a schematic diagram of the second diffusion plate of FIG. 1 in an operating state.

FIG. 11B is a schematic view of the second diffusion plate of FIG. 1 in another operation state.

FIG. 12 is a cross-sectional view illustrating a method of manufacturing a diffusion sheet according to another embodiment of the present disclosure.

FIG. 13A is a schematic diagram of a first diffuser plate in an operating state according to another embodiment of the present disclosure.

FIG. 13B is a schematic diagram of a first diffuser plate in another operating state according to another embodiment of the present disclosure.

FIG. 14A is a schematic diagram of a second diffuser plate in an operating state according to another embodiment of the present disclosure.

FIG. 14B is a schematic diagram of a second diffuser plate in another operating state according to another embodiment of the present disclosure.

Reference numerals:

10 display system 100 light source module

110, controller 112B, spectroscope

112G spectroscope 112R spectroscope

120 controller 122B spectroscope

122G spectroscope 122R spectroscope

130 light modulator 132 scanning track

200 collimating lens 300 imaging module

310 a first diffusion sheet 310', a first diffusion sheet

311 first substrate 312 first conductive film

313 first polymer layer 313a first polymer layer

313T upper surface 314 first alignment film

314a first alignment film 315 and alignment process

316a liquid crystal 316b liquid crystal

316c liquid crystal 316d liquid crystal

316e liquid crystal 316f liquid crystal

316g liquid crystal 316h liquid crystal

317e optical axis 317f optical axis

317g, optical axis 317h, optical axis

318 second alignment film 318a second alignment film

319 second Polymer layer 319a second Polymer layer

320 the second diffusion sheet 320

322 second conductive film 324 second substrate

330 polarization modulation element 400 optical module

402 mirror 404 mirror

406 mirror 408 mirror

410 prism 420 reflector

430 polarizing element 500 curved mirror

600 reflector 700 observer

702 line of sight 704 line of sight

B1 light source B2 light source

E electric axis G1 light source

G2 illuminant I1 first virtual image

I2 second virtual image I3 virtual image

I4 virtual image P1 first polarized image

P2 second polarized image PB1 first polarized beam

PB2 second polarized Beam PS1 first position

PS2 second position R roller

R1 light source R2 light source

S1 first light source group S2 second light source group

Detailed Description

In the following description, numerous implementation details are set forth in order to provide a thorough understanding of the present disclosure. It should be understood, however, that these implementation details are not to be interpreted as limiting the disclosure. That is, in some embodiments of the disclosure, these implementation details are not necessary, and thus should not be used to limit the disclosure. In addition, for the sake of simplicity, some conventional structures and elements are shown in the drawings. In addition, the dimensions of the various elements in the drawings are not necessarily to scale, for the convenience of the reader.

Furthermore, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to another element, as illustrated. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. Thus, the exemplary term "lower" can include both an orientation of "lower" and "upper," depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "below" or "beneath" may include both an orientation of above and below.

FIG. 1 illustrates a schematic diagram of a display system 10 according to some embodiments of the present disclosure. The display system 10 includes a light source module 100, an imaging module 300, an optical module 400, and a curved mirror 500.

The light source module 100 is configured to project a first polarized image P1 and a second polarized image P2. First polarized image P1 has a first polarization state and second polarized image P2 has a second polarization state different from the first polarization state. For example, the second polarization state is orthogonal to the first polarization state. In some embodiments, the first polarization state is 0 degree polarization and the second polarization state is 90 degree polarization. The imager module 300 is configured to form a first real image from the first polarized image P1 at a first position (e.g., the first position PS1 shown in fig. 3 and 4), and form a second real image from the second polarized image P2 at a second position (e.g., the second position PS2 shown in fig. 3 and 4). The optical module 400 is disposed between the curved mirror 500 and the imaging module 300. The optical module 400 is configured to project the first real image and the second real image onto the curved mirror 500 simultaneously, so that the first real image and the second real image generate a first virtual image I1 and a second virtual image I2 with different depths of field in the curved mirror 500. In this way, the display system 10 can generate two virtual images at the same time, which is helpful for providing multi-view images in a short time, thereby improving the safety of the observer 700 in driving on the road. In addition, the configuration of the display system 10 of some embodiments of the present disclosure may provide more images at the same scanning frequency than a display that provides a single image at a single time.

Fig. 2 is a schematic view of the light source module 100 of fig. 1. Refer to fig. 1 and 2 together. In some embodiments, the light source module 100 includes a first light source group S1, a second light source group S2, and a light modulator 130. The first light source group S1 is configured to generate a first polarized light beam PB1 with a first polarization state, and the second light source group S2 is configured to generate a second polarized light beam PB2 with a second polarization state. The light modulator 130 is configured to modulate the first polarized light beam PB1 into a first polarized image P1, and modulate the second polarized light beam PB2 into a second polarized image P2.

Specifically, in some embodiments, the first light source set S1 includes a controller 110, a beam splitter (beam splitter)112B, a beam splitter 112G and a beam splitter 112R, and a light source B1, a light source G1 and a light source R1. In some embodiments, light source R1 is a red laser diode, light source G1 is a green laser diode, and light source B1 is a blue laser diode. The light source R1, the light source G1 and the light source B1 can respectively generate red light, green light and blue light. The controller 110 is connected to the light source R1, the light source G1, and the light source B1, and is configured to drive the light source R1, the light source G1, and the light source B1 to emit red light, green light, and blue light with a first polarization state, respectively, which are incident to the beam splitter 112R, the beam splitter 112G, and the beam splitter 112B, respectively. The beam splitter 112B can reflect blue light, the beam splitter 112G can reflect green light and let blue light pass, and the beam splitter 112R can reflect red light and let blue light and green light pass, so that light emitted from the light source R1, the light source G1, and the light source B1 meet after passing through the beam splitter 112B, the beam splitter 112G, and the beam splitter 112R and become a first polarized light beam PB1 with a first polarization state.

Similarly, the second light source group S2 includes a controller 120, a second beam splitter 122B, a beam splitter 122G, a beam splitter 112R, a light source B2, a light source G2, and a light source R2. In some embodiments, light source R2 is a red laser diode, light source G2 is a green laser diode, and light source B2 is a blue laser diode. The light source R2, the light source G2 and the light source B2 can respectively generate red light, green light and blue light. The controller 120 is connected to the light source R2, the light source G2, and the light source B2, and is configured to drive the light source R2, the light source G2, and the light source B2 to emit red light, green light, and blue light with a second polarization state, respectively, which are incident to the beam splitter 122R, the beam splitter 122G, and the beam splitter 122B, respectively. The beam splitter 122B can reflect blue light, the beam splitter 122G can reflect green light and let blue light pass, and the beam splitter 122R can reflect red light and let blue light and green light pass, so that the light emitted from the light source R2, the light source G2, and the light source B2 is combined into the second polarized light beam PB2 with the second polarization state after passing through the beam splitter 122B, the beam splitter 122G, and the beam splitter 122R.

The light modulator 130 is used for modulating the first polarized light beam PB1 into a first polarized image P1 and modulating the second polarized light beam PB2 into a second polarized image P2. In some embodiments, the first polarized image P1 with the first polarization state can be modulated on the imager module 300 as an inverted triangle, and the second polarized image P2 with the second polarization state can be modulated on the imager module 300 as a regular triangle, wherein the two polarizations do not interfere with each other. It should be noted that the above-mentioned patterns (inverted triangle and regular triangle) are only examples and are not intended to limit the present disclosure. In other embodiments, the first polarized image P1 and the second polarized image P2 can be images with different viewing angles, respectively.

In some embodiments, the light source module 100 is a Laser Beam Scanning (LBS). Light modulator 130 may be a mirror of a micro-electromechanical system (MEMS) element. As shown in FIG. 2, the first polarized beam PB1 and the second polarized beam PB2 are incident on the light modulator 130 at the same time, and the light modulator 130 directs the first polarized beam PB1 and the second polarized beam PB2 to the imaging module 300. The light modulator 130 rotates its reflective surface to sequentially direct the first polarized beam PB1 and the second polarized beam PB2 to different positions of the imaging module 300. For example, the reflective surface of light modulator 130 is rotated to form a scanning track 132 on imaging module 300. When the scanning track 132 reaches the position of the first polarized image P1, the controller 110 of the first light source group S1 turns on at least one of the light sources B1, G1 and R1, so that the first polarized light beam PB1 strikes the position of the first polarized image P1. Similarly, when the scanning track 132 reaches the position of the second polarized image P2, the controller 120 of the second light source group S2 turns on at least one of the light source B2, the light source G2 and the light source R2, so that the second polarized light beam PB2 strikes the position of the second polarized image P2. When the scanning track 132 is located at a position other than the first polarized image P1 and the second polarized image P2, the controller 110 turns off all the light sources B1, G1 and R1, and the controller 120 turns off all the light sources B2, G2 and R2.

Returning to fig. 1. In some embodiments, display system 10 further comprises a collimating lens 200. The collimating lens 200 is disposed between the light source module 100 and the imaging module 300. The collimating lens 200 is configured to collimate the first polarized image P1 and the second polarized image P2, so that the first polarized image P1 and the second polarized image P2 incident on the collimating lens 200 can be collimated into parallel light.

FIG. 3 is a schematic diagram illustrating optical paths of the display system 10 of FIG. 1 at a first timing according to some embodiments of the present disclosure. Referring to fig. 1 and 3 together, in some embodiments, the image forming module 300 includes a first diffusion plate 310 and a second diffusion plate 320. The first diffusion sheet 310 is disposed between the light source module 100 and the optical module 400, and the second diffusion sheet 320 is disposed between the first diffusion sheet 310 and the optical module 400. In some embodiments, the first diffusion sheet 310 and the second diffusion sheet 320 have different liquid crystal axial directions, such that the first polarized image P1 is scattered by the first diffusion sheet 310 to form a first real image, and the second polarized image P2 is not scattered after passing through the first diffusion sheet 310. The second polarized image P2 is scattered after passing through the second diffusion sheet 320 to form a second real image, and the first polarized image P1 is not scattered (transmitted) after passing through the second polarizing sheet. In detail, when a voltage is not applied to the first diffusion sheet 310, the first diffusion sheet 310 has a liquid crystal axis direction parallel to the first polarization state and perpendicular to the second polarization state, so that the first polarization image P1 having the first polarization state is scattered after passing through the first diffusion sheet 310, and the second polarization image P2 is not scattered after directly penetrating through the first diffusion sheet 310. When a voltage is applied to the first diffusion sheet 310, the first diffusion sheet 310 has a liquid crystal axis direction parallel to the traveling direction of the first polarized image P1 and the second polarized image P2, so that both the first polarized image P1 and the second polarized image P2 directly penetrate through the first diffusion sheet 310 without scattering. In addition, when a voltage is not applied to the second diffusion sheet 320, the second diffusion sheet 320 has a liquid crystal axis direction perpendicular to the first polarization state and parallel to the second polarization state, the first polarization image P1 directly penetrates the second diffusion sheet 320 without being scattered, and the second polarization image P2 is scattered after passing through the second diffusion sheet 320. When a voltage is applied to the second diffusion sheet 320, the second diffusion sheet 320 has a liquid crystal axis direction parallel to the traveling direction of the first polarized image P1 and the second polarized image P2, so that the first polarized image P1 and the second polarized image P2 both directly penetrate through the second diffusion sheet 320 and are not scattered.

When the display system 10 is in the first timing, the first diffusion sheet 310 and the second diffusion sheet 320 are turned off (no voltage is applied to the first diffusion sheet 310 and the second diffusion sheet 320). The first polarized image P1 having the first polarization state is scattered after passing through the first diffusion sheet 310 to form a first real image at the first position PS1, and is not scattered after passing through the second diffusion sheet 320. Furthermore, the second polarized image P2 with the second polarization state is not scattered by the first diffusion plate 310 and is scattered by the second diffusion plate 320 to form a second real image at the second position PS 2. In some embodiments, the image forming position is controlled by switching the long and short axes of the liquid crystals of the first or

second diffusion sheet

310 or 320 to achieve the characteristic of the first or second polarized image P1 or P2 scattering after passing through the diffusion sheet (the first or second diffusion sheet 310 or 320). In detail, the first diffusion sheet 310 and the second diffusion sheet 320 may include a first glass layer, a first conductive film on the first glass layer, a liquid crystal on the first conductive film, a second conductive film on the liquid crystal, and a second glass layer on the second conductive film, respectively. When the refractive index of the short axis of the liquid crystal of the first diffusion sheet 310 or the second diffusion sheet 320 is equal to the refractive index of the glass layer and the refractive index of the long axis of the liquid crystal is greater than the refractive index of the glass layer, the first polarized image P1 or the second polarized image P2 is scattered after passing through the diffusion sheet (the first diffusion sheet 310 or the second diffusion sheet 320), and when the refractive index of the long axis of the liquid crystal is equal to the refractive index of the glass layer, the first polarized image P1 or the second polarized image P2 is not scattered after passing through the diffusion sheet (the first diffusion sheet 310 or the second diffusion sheet 320).

In some embodiments, the imaging module 300 further comprises a polarization modulation element 330. The polarization modulation element 330 is disposed between the second diffusion sheet 320 and the optical module 400. The polarization modulation element 330 is used to change the polarization states of the first polarized image P1 and the second polarized image P2. In some embodiments, the polarization modulation element 330 can be, for example, a twisted nematic liquid crystal cell (TN cell) that can change the polarization state of the incident polarized images (the first polarized image P1 and the second polarized image P2). The polarization modulation element 330 is turned on by applying a voltage to the polarization modulation element 330, or the polarization modulation element 330 is turned off by removing the voltage from the polarization modulation element 330, so as to change the polarization state of the polarization image incident to the polarization modulation element 330 or keep the polarization state of the polarization image unchanged. In other words, when the polarization modulation element 330 is turned on, the polarization modulation element 330 is used to pass the first polarization image P1 and maintain the first polarization state, and pass the second polarization image P2 and maintain the second polarization state. When the polarization modulation element 330 is turned off (details will be described in fig. 4), the polarization modulation element 330 is used to convert the first polarized image P1 into the third polarized image P3 with the second polarization state and convert the second polarized image P2 into the fourth polarized image P4 with the first polarization state. In some embodiments, the polarization modulation element 330 may include two transparent substrates, a liquid crystal disposed between the two transparent substrates, and a driving element for adjusting the polarization direction.

When the display system 10 is in the first timing sequence, the polarization modulation element 330 is turned on (for example, a voltage is applied to the polarization modulation element 330), and the polarization modulation element 330 does not change the polarization states of the first polarization image P1 and the second polarization image P2. In other words, the first polarized image P1 still maintains the first polarization state after passing through the polarization modulation element 330, and the second polarized image P2 still maintains the second polarization state after passing through the polarization modulation element 330, and then the first polarized image P1 and the second polarized image P2 are incident to the optical module 400 together.

Returning to fig. 1. In some embodiments, optical module 400 includes a prism 410. The prism 410 is disposed corresponding to the polarization modulation element 330, and the prism 410 has a mirror 402, and the mirror 402 can reflect the first polarized image P1 and let the second polarized image P2 pass through. In detail, when first polarized image P1 has the first polarization state, first polarized image P1 is reflected by mirror 402 of prism 410. When second polarized image P2 has the second polarization state, second polarized image P2 is transmitted through mirror 402 of prism 410. Mirror 402 has a polarization-selective coating, such as a highly polarized conversion film (APCF) or a Dual Brightness Enhancement Film (DBEF), thereon, such that a polarized light beam having the second polarization state is transmitted therethrough and a polarized light beam having the first polarization state is reflected. In some embodiments, prism 410 further has mirror 404 coupled to mirror 402, mirror 406 coupled to mirror 404, and mirror 408 coupled to mirror 402 and mirror 406. When the polarized light beam has the second polarization state, the polarized light beam (e.g., the second polarized image P2) passes through the mirror 402, reaches the mirror 404, is reflected to the mirror 406, reaches the mirror 406, is reflected to the mirror 408, reaches the mirror 408, and is reflected to pass through the mirror 402.

In some embodiments, the optical module 400 further includes a mirror 420 and a polarization element 430. The mirror 420 is disposed on the mirror surface 404 of the prism 410 and configured to reflect the second polarized image P2. The polarization element 430 is disposed between the mirror surface 404 of the prism 410 and the reflection mirror 420, and is spaced apart from the mirror surface 402, and the polarization element 430 is configured to eliminate stray light. Specifically, polarizing element 430 is configured to reflect second polarized image P2 and eliminate first polarized image P1 incident on polarizing element 430. Therefore, if some of the first polarized image P1 passes through the mirror 402 to reach the mirror 404, the first polarized image P1 incident on the polarizer 430 is eliminated by the polarizer 430, and only the second polarized image P2 can be reflected by the polarizer 430, so that the polarizer 430 can be used to purify the image of the second polarized image P2, thereby reducing the image interference between the first polarized image P1 and the second polarized image P2.

The first polarized image P1 and the second polarized image P2 passing through the optical module 400 then reach the curved mirror 500. In some embodiments, the curved mirror 500 can be a partially transmissive partially reflective optical element coated with a highly reflective dielectric material. In some embodiments, the shape of the reflective surface of the curved mirror 500 is curved (freeform) or non-freeform), segmented, progressive focal length and/or segmented prism, or fresnel lens molding, and may be metallic or holographic coated. In some embodiments, the curved mirror 500 is a curved mirror, lens, or combination thereof having a particular magnification.

In some embodiments, the display system 10 further comprises a mirror 600. The first polarized image P1 and the second polarized image P2 reflected from the curved mirror 500 are incident on the mirror 600, and the first polarized image P1 and the second polarized image P2 are reflected by the mirror 600 to the observer 700 (in the eye), so that the observer 700 can observe the first virtual image I1 and the second virtual image I2. The first virtual image I1 and the second virtual image I2 can be formed simultaneously at the same time sequence, and correspond to the first polarized image P1 and the second polarized image P2 with different polarization states, respectively. In some embodiments, the first virtual image I1 is aligned with the second virtual image I2 on the line of

sight

702 or 704 of the observer 700 corresponding to the mirror 600. In some embodiments, the mirror 600 is made of glass.

Reference is also made to fig. 1 and 3. In some embodiments, after the first polarized image P1 forms the first real image at the first position PS1, the optical path between the first real image and the curved mirror 500 is the sum of the path passing through the second diffusion sheet 320 and the polarization modulation element 330, the path from the polarization modulation element 330 to the mirror surface 402 of the prism 410, and the path reflected by the mirror surface 402 to the curved mirror 500, and the optical module 400 is configured to project the first real image into the curved mirror 500 to generate the first virtual image I1. After the second polarized image P2 forms the second real image at the second position PS2, the optical path between the second real image and the curved mirror 500 is the sum of the path from the polarization modulation element 330 to the mirror 402 of the prism 410, the path in the prism 410, and the path reflected by the mirror 402 to the curved mirror 500, and the optical module 400 is configured to project the second real image into the curved mirror 500 to generate the second virtual image I2. In some embodiments, the optical module 400 projects the first real image and the second real image to the curved mirror 500 simultaneously. As described above, since the optical path between the first real image and the curved mirror 500 is different from the optical path between the second real image and the curved mirror 500, the first virtual image I1 and the second virtual image I2 with different depths of field are generated in the curved mirror 500 by the first real image and the second real image, that is, the distance from the second virtual image I2 to the observer 700 is greater than the distance from the first virtual image I1 to the observer 700, so that the observer 700 can simultaneously obtain visual images with different depths of field, and therefore, the safety of the observer 700 in road driving can be improved.

In some embodiments, display system 10 may display more than two virtual images. FIG. 4 is a schematic diagram illustrating optical paths of the display system 10 of FIG. 1 at a second timing different from the first timing according to some embodiments of the present disclosure. Referring to fig. 1 and 4 together, when the display system 10 is at the second timing, the first diffusion plate 310 and the second diffusion plate 320 are turned off (no voltage is applied to the first diffusion plate 310 and the second diffusion plate 320), the first polarized image P1 with the first polarization state is scattered after passing through the first diffusion plate 310 to form a first real image at the first position PS1, and is not scattered after passing through the second diffusion plate 320. Furthermore, the second polarized image P2 with the second polarization state is not scattered by the first diffusion sheet 310 and is scattered by the second diffusion sheet 320 to form a second real image at the second position PS 2.

The first real image and the second real image are incident on the polarization modulation element 330. When the display system 10 is at the second timing, the polarization modulation element 330 is turned off (e.g., no voltage is applied to the polarization modulation element 330), and the polarization modulation element 330 changes the polarization states of the first polarization image P1 and the second polarization image P2. In other words, the polarization modulation element 330 is used to convert the first polarized image P1 with the first polarization state into the third polarized image P3 with the second polarization state, and convert the second polarized image P2 with the second polarization state into the fourth polarized image P4 with the first polarization state. Next, since mirror 402 of prism 410 has a polarization-selective coating, third polarized image P3 having the second polarization state is allowed to pass through, and fourth polarized image P4 having the first polarization state is reflected. Since the optical path of the third polarized image P3 in the prism 410 is the same as the optical path of the second polarized image P2 (fig. 3), and the optical path of the fourth polarized image P4 in the prism 410 is the same as the optical path of the first polarized image P1 (fig. 3), further description is omitted here. In some embodiments, the optical path between the first real image and the curved mirror 500 at the second timing is the sum of the path passing through the second diffusion sheet 320 and the polarization modulation element 330, the path from the polarization modulation element 330 to the mirror 402 of the prism 410, the path in the prism 410, and the path reflected by the mirror 402 to the curved mirror 500, and the optical module 400 is configured to project the first real image into the curved mirror 500 to generate the third virtual image I3. The optical path between the second real image and the curved mirror 500 at the second timing is the sum of the path from the polarization modulation element 330 to the mirror 402 of the prism 410 and the path reflected by the mirror 402 to the curved mirror 500, and the optical module 400 is configured to project the second real image into the curved mirror 500 to generate the fourth virtual image I4. In some embodiments, the optical module 400 projects the first real image and the second real image to the curved mirror 500 simultaneously. As described above, since the optical path between the first real image and the curved mirror 500 is different from the optical path between the second real image and the curved mirror 500, the first real image and the second real image generate the third virtual image I3 and the fourth virtual image I4 with different depths of field in the curved mirror 500, that is, the distance from the third virtual image I3 to the observer 700 is greater than the distance from the fourth virtual image I4 to the observer 700, so that the observer 700 can simultaneously obtain visual images with different depths of field, and therefore, the safety of the observer 700 in road driving can be improved.

In some embodiments, as shown in fig. 3 and 4, by rapidly switching the first timing sequence and the second timing sequence, the observer can see four virtual images (the first virtual image I1 to the fourth virtual image I4), so that the observer can simultaneously obtain visual images with different depths of field, thereby improving the safety of the observer in road driving. For example, when the polarization modulation element 330 is turned off, the imaging module 300 may enable the first real image to generate a third virtual image I3 with a different depth of field from the first virtual image I1 in the curved mirror 500, and enable the second real image to generate a fourth virtual image I4 with a different depth of field from the second virtual image I2 in the curved mirror 500, so that the observer 700 sees multiple virtual images with different distances and distances simultaneously. Because the polarization modulation device 330 has a fast response characteristic, the observer 700 can see a plurality of images with different distances at the same time by fast switching the first polarized image P1 and the second polarized image P2 with two different polarization states, thereby improving the safety of the observer 700 in driving on the road.

FIG. 5A is a schematic diagram of the polarization modulation element 330 of FIG. 1 in one operating state, and FIG. 5B is a schematic diagram of the polarization modulation element 330 of FIG. 1 in another operating state. As shown in fig. 5A, when the polarization modulation element 330 is turned off (for example, no voltage is applied to the polarization modulation element 330), the polarization modulation element 330 changes the polarization state of the polarized light beam, so that the polarization state of the polarized light beam incident on the polarization modulation element 330 is different from the polarization state of the polarized light beam after passing through the polarization modulation element 330. Specifically, the polarization modulation element 330 changes the polarization state of the polarized light beam to rotate the polarization of the polarized light beam by 90 degrees. After being incident on the polarization modulation element 330, the first polarization image P1 with the first polarization state is converted into a third polarization image P3 with the second polarization state by the polarization modulation element 330. After being incident on the polarization modulation element 330, the second polarization image P2 with the second polarization state is converted into a fourth polarization image P4 with the first polarization state by the polarization modulation element 330.

As shown in fig. 5B, when the polarization modulation element 330 is turned on (e.g., a voltage is applied to the polarization modulation element 330), the polarization modulation element 330 does not change the polarization state of the polarized light beam, so that the polarization state of the polarized light beam incident on the polarization modulation element 330 is the same as the polarization state of the polarized light beam after passing through the polarization modulation element 330. Specifically, the first polarization image P1 with the first polarization state still maintains the first polarization state after being incident on the polarization modulation element 330. The second polarization image P2 with the second polarization state still maintains the second polarization state after being incident on the polarization modulation element 330.

Fig. 6 to 9 are cross-sectional views illustrating a method of manufacturing a diffusion sheet according to some embodiments of the present disclosure at various steps, wherein the diffusion sheet may correspond to the first diffusion sheet 310 or the second diffusion sheet 320 in fig. 1 to 4. Referring to fig. 6, a first conductive film 312 is formed on the first substrate 311. In some embodiments, the first conductive film 312 is formed on the first substrate 311 by coating. The first substrate 311 may be a substrate that transmits visible light and has an insulating surface. In some embodiments, the first substrate 311 is a glass substrate, and an alkali-free glass substrate such as barium borosilicate glass, aluminoborosilicate glass, or aluminosilicate glass can be used. In some other embodiments, the first substrate 311 is a quartz substrate, a sapphire substrate, or other suitable substrate. The first conductive film 312 is a light-transmitting conductive film, such as an oxide conductive film. In some embodiments, the first conductive film 312 comprises indium oxide containing tungsten oxide, indium tin oxide containing tungsten oxide, indium oxide containing titanium oxide, Indium Tin Oxide (ITO), indium zinc oxide, indium tin oxide with silicon oxide added, or other suitable materials.

Referring to fig. 7, a first polymer layer 313 is formed on the first conductive film 312. In some embodiments, the first polymer layer 313 is formed on the first conductive film 312. The first polymer layer 313 may comprise a conductive polymer, such as polyaniline and its derivatives, polyparaffins and its derivatives, polysilphins and its derivatives, combinations of the foregoing, or other suitable materials.

Referring to fig. 8, the roller R is pressed on the upper surface 313T of the first polymer layer 313, such that the upper surface 313T of the first polymer layer 313 forms a non-flat rough surface. For example, the first polymer layer 313 has a non-uniform thickness. In some embodiments, the roller R is used to stamp the upper surface 313T of the first polymer layer 313, and the surface of the first polymer layer 313 can be printed with at least one parallel groove, so that the subsequently formed liquid crystal can be aligned along the direction of the groove, and the liquid crystal can be aligned along the same direction. After the roller R is imprinted on the upper surface 313T of the first polymer layer 313, a curing process is performed on the upper surface 313T of the first polymer layer 313.

Referring to fig. 9, a first alignment film 314 is formed on the first polymer layer 313. In some embodiments, the first alignment film 314 is formed on the first polymer layer 313 in a coating manner. The first alignment film 314 may include polyimide (polyimide). In some embodiments, the alignment process 315 is performed on the first alignment film 314, so that the liquid crystal on the first alignment film 314 can be oriented by the interaction between the molecules, thereby controlling the alignment of the liquid crystal molecules according to a specific direction and a predetermined tilt angle. For example, when the first diffusion sheet 310 and the second diffusion sheet 320 are manufactured, the alignment directions of the first alignment film 314 are different, so that the liquid crystals of the first diffusion sheet 310 and the second diffusion sheet 320 have different axial directions.

Fig. 10A is a schematic view of the first diffusion sheet 310 of fig. 1 in one operation state, and fig. 10B is a schematic view of the first diffusion sheet 310 of fig. 1 in another operation state. The first diffusion sheet 310 includes a first substrate 311, a first conductive film 312, a first polymer layer 313, a first alignment film 314, a liquid crystal 316a, a second alignment film 318, a second polymer layer 319, a second conductive film 322, and a second substrate 324, which are sequentially arranged, wherein the liquid crystal 316a is located between the first alignment film 314 and the second alignment film 318. As shown in fig. 10A, when a voltage is not applied to the first diffusion sheet 310, the liquid crystal 316a has a liquid crystal axis direction parallel to the incident surface and extending in the left-right direction of the drawing.

Referring to fig. 10B, when a voltage is applied to the first diffusion sheet 310, the liquid crystal 316B has a liquid crystal axis direction parallel to the incident surface and perpendicular to the length direction of the first substrate 311 and the second substrate 324.

Fig. 11A is a schematic view illustrating the second diffusion sheet 320 of fig. 1 in one operation state, and fig. 11B is a schematic view illustrating the second diffusion sheet 320 of fig. 1 in another operation state. The material and arrangement details of the second diffusion plate 320 are substantially the same as or similar to those of the first diffusion plate 310, and thus are not repeated here. As shown in fig. 11A, when a voltage is not applied to the second diffusion sheet 320, the liquid crystal 316c has a liquid crystal axis direction parallel to the incident surface and going in and out of the paper surface.

Referring to fig. 11B, when a voltage is applied to the second diffusion sheet 320, the liquid crystal 316d has a liquid crystal axis direction perpendicular to the incident surface and perpendicular to the length direction of the first substrate 311 and the second substrate 324.

Fig. 12 is a cross-sectional view illustrating a method of manufacturing a diffusion sheet according to another embodiment of the present disclosure, where the diffusion sheet may correspond to the first diffusion sheet 310 or the second diffusion sheet 320 of fig. 1. After the step of fig. 7, a first alignment film 314a is formed on the first polymer layer 313 a. Then, an alignment process 315 is performed on the first alignment film 314a, so that the liquid crystal on the first alignment film 314a can achieve an alignment effect due to the interaction between the molecules, thereby controlling the liquid crystal molecules to be aligned in a specific direction and a predetermined tilt angle. In some embodiments, the embodiment of fig. 12 is different from the embodiment of fig. 9 in that the first polymer layer 313a and the first alignment film 314a of fig. 12 both have substantially flat upper surfaces. Specifically, after the first polymer layer 313a is formed on the first conductive film 312, the first polymer layer 313a is not subjected to an imprinting process (e.g., a roller R is imprinted on the first polymer layer 313a as shown in fig. 8), so the first polymer layer 313a and the first alignment film 314a do not have a non-flat rough upper surface and have a substantially uniform thickness. The diffuser of FIG. 12 is substantially the same or similar in material and arrangement to the diffuser of FIG. 9 and will not be repeated here.

Fig. 13A illustrates a schematic view of a first diffusion sheet 310 'according to another embodiment of the present disclosure in one operation state, and fig. 13B illustrates a schematic view of a first diffusion sheet 310' according to another embodiment of the present disclosure in another operation state. The first diffusion sheet 310' includes a first substrate 311, a first conductive film 312, a first polymer layer 313a, a first alignment film 314a, a liquid crystal 316e, a second alignment film 318a, a second polymer layer 319a, a second conductive film 322, and a second substrate 324, which are sequentially arranged, wherein the liquid crystal 316e is located between the first alignment film 314a and the second alignment film 318 a. The difference between the first diffusion sheet 310' of fig. 13A and the first diffusion sheet 310 of fig. 10A is that the first polymer layer 313A, the first alignment film 314a, the second polymer layer 319a, and the second alignment film 318a further include liquid crystal 316 e. As shown in FIG. 13A, liquid crystal 316e is a polymer-dispersed liquid crystal (PDLC) liquid crystal, and an optical axis 317e in liquid crystal 316e represents a liquid crystal axis direction in liquid crystal 316 e. When no voltage is applied to the first diffusion sheet 310', the electric axis E is not parallel to the optical axis 317E of the liquid crystal 316E. In addition, the directions of the optical axes 317e of the liquid crystals 316e are random and non-uniform. Wherein the electric axis E is the direction of the electric field after the voltage is applied to the first conductive film 312 and the second conductive film 322.

As shown in fig. 13B, when a voltage is applied to the first diffusion sheet 310', the electrical axis E is parallel to the optical axis 317f of the liquid crystal 316 f. Therefore, by applying/not applying a voltage to the first conductive film 312 and the second conductive film 322, the directions of the optical axes (optical axis 317 e/optical axis 317f) of the liquid crystals (liquid crystals 316 e/liquid crystals 316f) can be changed, thereby changing the transmittance of the first diffusion sheet 310'.

Fig. 14A illustrates a schematic view of a second diffusion sheet 320 'according to another embodiment of the present disclosure in one operation state, and fig. 14B illustrates a schematic view of a second diffusion sheet 320' according to another embodiment of the present disclosure in another operation state. The material and the arrangement details of the second diffusion plate 320 'are substantially the same as or similar to those of the first diffusion plate 310', and thus, a description thereof will not be repeated. As shown in fig. 14A, when a voltage is not applied to the second diffusion sheet 320', the electric axis E is not parallel to the optical axis 317g of the liquid crystal 316 g. In addition, the directions of the optical axes 317g of the liquid crystals 316g are random and non-uniform.

As shown in fig. 14B, when a voltage is applied to the second diffusion sheet 320', the optical axis 317h of the liquid crystal 316h is in a parallel substrate direction, and the electrical axis E is perpendicular to the optical axis 317 h. Therefore, by applying/not applying a voltage to the first conductive film 312 and the second conductive film 322, the direction of the optical axis (optical axis 317 g/optical axis 317h) of the liquid crystal (liquid crystal 316 g/liquid crystal 316h) can be changed, thereby changing the transmittance of the second diffusion sheet 320'.

Although the present disclosure has been described with reference to exemplary embodiments, other embodiments are possible and are not intended to limit the present disclosure. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

Those skilled in the art can make various changes and substitutions without departing from the spirit and scope of the present disclosure, and therefore all such changes and substitutions are intended to be included within the scope of the present disclosure as set forth in the appended claims.

Claims

1. A display system, comprising:

a light source module configured to project a first polarized image and a second polarized image, wherein the first polarized image has a first polarization state and the second polarized image has a second polarization state different from the first polarization state;

the imaging module is configured to form a first real image of the first polarized image at a first position and form a second real image of the second polarized image at a second position;

a curved mirror; and

the optical module is arranged between the curved mirror and the imaging module, and the optical module is configured to project the first real image and the second real image to the curved mirror simultaneously, so that the first real image and the second real image generate a first virtual image and a second virtual image which have different depths of field in the curved mirror.

2. The display system of claim 1, wherein the imaging module comprises:

the first diffusion sheet is arranged between the light source module and the optical module, wherein the first polarized image is scattered after passing through the first diffusion sheet to form the first real image, and the second polarized image is not scattered after passing through the first diffusion sheet; and

and the second diffusion sheet is arranged between the first diffusion sheet and the optical module, wherein the second polarized image is scattered after passing through the second diffusion sheet to form the second real image, and the first polarized image is not scattered after passing through the second polarization sheet.

3. A display system as recited in claim 2, wherein the first diffuser and the second diffuser have different liquid crystal axes.

4. The display system of claim 2, wherein the imaging module further comprises:

and the polarization modulation element is arranged between the second diffusion sheet and the optical module, is used for converting the first polarization image into a third polarization image with the second polarization state when the polarization modulation element is closed, and is used for allowing the first polarization image to pass through and keeping the first polarization state when the polarization modulation element is opened.

5. The display system of claim 4, wherein the imaging module further causes the first real image to generate a third virtual image in the curved mirror with a depth of field different from the first virtual image when the polarization modulation element is turned off.

6. The display system of claim 1, wherein the optical module comprises:

a prism having a plurality of faces, a first face of the faces capable of reflecting the first polarized image and passing the second polarized image.

7. The display system of claim 6, wherein the optical module further comprises:

a mirror disposed on a second face of the prism and configured to reflect the second polarized image; and

a polarizing element disposed between the second face of the prism and the mirror and configured to reflect the second polarized image and to eliminate the first polarized image incident to the polarizing element.

8. The display system of claim 6, wherein the total number of faces of the prism is an even number.

9. The display system of claim 1, wherein the light source module comprises:

a first light source set configured to generate a first polarized light beam having the first polarization state;

a second light source set configured to generate a second polarized light beam having the second polarization state; and

and the light modulator is used for modulating the first polarized light beam into the first polarized image and modulating the second polarized light beam into the second polarized image.

10. The display system of claim 1, further comprising a collimating lens disposed between the light source module and the imaging module and configured to collimate the first polarized image and the second polarized image.