# US 2021/0333545 A1 · Display apparatus, display method thereof, and head-up display apparatus

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- Number: US 2021/0333545 A1
- Document ID: US20210333545A1
- Status: Published application
- Kind: A1
- Application number: 16/344,520
- Filed: 2018-09-19
- Published: 2021-10-28
- Earliest claimed: 2018-01-02
- Assignees: Boe Technology Group Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.
- Inventors: Tao Hong
- Web page: https://patentgrep.com/patent/US20210333545A1

## CPC

- G02B 27/0101: {characterised by optical features (G02B27/0172 takes precedence)}
- G02B 27/0172: {characterised by optical features}
- G02B 5/3083: {Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001)}
- G02B 27/283: {used for beam splitting or combining}
- G02B 27/286: {for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34)}
- G02F 1/13756: {the liquid crystal selectively assuming a light-scattering state (G02F1/1334, G02F1/13718 take precedence)}
- G02B 2027/014: {comprising information/image processing systems}
- G02B 2027/0185: {Displaying image at variable distance}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

A display apparatus includes a display unit (2) and an image processing unit (3). The display unit may be configured to project light for a display image. The image processing unit may be configured to change polarization direction of the light for the display image and to selectively scatter or transmit the light for the display image based on the polarization direction of the light for the display image.

## Claims

### Claim 1

A display apparatus, comprising
a display unit; and
an image processing unit,
wherein the display unit is configured to project light for a display image; and the image processing unit is configured to change polarization direction of the light for the display image and to selectively scatter or transmit the light for the display image based on the polarization direction of the light for the display image.

### Claim 2 (depends on 1)

The display apparatus according to claim 1, wherein the display apparatus is configured to display the display image at different distances from a user.

### Claim 3 (depends on 1)

The display apparatus according to claim 1, wherein the image processing unit comprises a first polarization conversion element, a first lens element, and a liquid crystal dispersing element,
wherein the first polarization conversion element is configured to convert the polarization direction of the light for the display image into a first polarization direction or a second polarization direction;
the first lens element is configured to deflect the light of the first polarization direction and not to change direction of the light of the second polarization direction; and
the liquid crystal dispersing element is configured to scatter the light of the first polarization direction and transmit the light of the second polarization direction.

### Claim 4 (depends on 3)

The display apparatus according to claim 3, the image processing unit further comprising a first polarization beam splitter,
wherein the first polarization beam splitter is configured to receive the light of the first polarization direction scattered by the liquid crystal dispersing element or the light of the second polarization direction transmitted by the liquid crystal dispersing element, and to cause an exit direction of the light of the first polarization direction to be different from an exit direction of the light of the second polarization direction.

### Claim 5 (depends on 1)

The display apparatus according to claim 1, wherein the image processing unit comprises a second polarization conversion element, a second lens element, a second polarization beam splitter, and a scattering element,
wherein the second polarization conversion element is configured to convert the polarization direction of the light for the display image into a first polarization direction or a second polarization direction;
the second lens element is configured to deflect the light of the first polarization direction and not to change direction of the light of the second polarization direction; and
the scattering element is configured to scatter the light of the first polarization direction emitted by the second polarization beam splitter.

### Claim 6 (depends on 3)

The display apparatus according to claim 3, wherein the display unit projects light for a first display image, light for a second display image, or light for the first display image and light for the second display image alternatively according to a timing diagram; and
in case that the display unit projects the light for the first display image, the first polarization conversion element or the second polarization conversion element converts the polarization direction of the light for the first display image into the first polarization direction, and in case that the display unit projects the light for the second display image, the first polarization conversion element or the second polarization conversion element converts the polarization direction of the light for the second display image into the second polarization direction.

### Claim 7 (depends on 3)

The display apparatus according to claim 3, further comprising a control unit, wherein the liquid crystal dispersing element comprises a polymer dispersed liquid crystal element, and the control unit is configured to turn on the polymer dispersed liquid crystal element to scatter the light of the first polarization direction or turn off the polymer dispersed liquid crystal element to transmit the light of the second polarization direction.

### Claim 8 (depends on 3)

The display apparatus according to claim 3, wherein the first lens element comprises a birefringent lens, the birefringent lens comprising a hollow refractive material and a filler, a refractive index of the hollow refractive material being smaller than that of the filler with respect to incident light of the first polarization direction, and the refractive index of the hollow refraction material being the same as that of the filler with respect to incident light of the second polarization direction.

### Claim 9 (depends on 3)

The display apparatus according to claim 3, further comprising a first reflection unit including a first mirror assembly, wherein the first reflection unit is configured to reflect the light of the first polarization direction scattered by the liquid crystal dispersion element and/or the light of the second polarization direction transmitted through the liquid crystal dispersion element to form the display image at different distances from an user, respectively.

### Claim 10 (depends on 3)

The display apparatus according to claim 3, further comprising a second reflection unit including a second mirror assembly and a third mirror assembly,
wherein the second mirror assembly is configured to reflect the light of the first polarization direction emitted by the first polarization beam splitter to form the display image; and
the third mirror assembly is configured to reflect the light of the second polarization direction emitted by the first polarization beam splitter to the second mirror assembly.

### Claim 11 (depends on 5)

The display apparatus according to claim 5, further comprising a third reflection unit including a fourth mirror assembly and a fifth mirror assembly,
wherein the fourth mirror assembly is configured to reflect the light of the first polarization direction scattered by the scattering element to form the display image; and
the fifth mirror assembly is configured to reflect the light of the second polarization direction emitted by the second polarization beam splitter to the fourth mirror assembly.

### Claim 12 (depends on 1)

The display apparatus according to claim 1, further comprising a mode selection unit,
wherein the mode selection unit is configured to select a display mode, the display mode including a first distance display mode, a second distance display mode, and a dual-distance display mode.

### Claim 13 (depends on 12)

The display apparatus according to claim 12, wherein in the first distance display mode, the display unit projects light for a first display image; the image processing unit converts polarization direction of the light for the first display image into the first polarization direction and scatters the light for the first display image to display the first display image at a first distance;
in the second distance display mode, the display unit projects light for a second display image; the image processing unit converts the polarization direction of the light for the second display image into the second polarization direction and transmits the light for the second display image to display the second display image at a second distance; and
in the dual-distance display mode, the display unit projects light for the first display image and light for the second display image alternatively, and the image processing unit displays the first display image and the second display image at the first distance and the second distance, respectively.

### Claim 14

A display method, comprising:
projecting a light for a display image; and
changing polarization direction of the light for the display image and selectively scattering or transmitting the light for the display image based on the polarization direction of the light for the display image.

### Claim 15 (depends on 14)

The display method according to claim 14, wherein changing polarization direction of the light for the display image and selectively scattering or transmitting the light for the display image based on the polarization direction of the light for the display image comprises:
converting the polarization direction of the light for the display image into a first polarization direction or a second polarization direction;
deflecting the light of the first polarization direction and/or maintaining the direction of the light of the second polarization direction; and
scattering the deflected light of the first polarization direction and/or transmitting the light of the second polarization direction.

### Claim 16 (depends on 14)

The display method according to claim 14, wherein changing polarization direction of the light for the display image and selectively scattering or transmitting the light for the display image based on the polarization direction of the light for the display image comprises:
converting the polarization direction of the light for the display image into a first polarization direction or a second polarization direction;
deflecting the light of the first polarization direction and/or maintaining the direction of the light of the second polarization direction;
causing an exit direction of the light of the first polarization direction to be different from an exit direction of the light of the second polarization direction; and
scattering the light of the first polarization direction.

### Claim 17 (depends on 15)

The display method according to claim 15, wherein the display image comprises a first display image and a second display image, the display method comprising:
projecting a light for the first display image, a light for the second display image, or the light for the first display image and the light for the second display image alternatively;
converting polarization direction of the light for the first display image into the first polarization direction in case that the light for the first display image is projected; and
converting polarization direction of the light for the second display image into the second polarization direction in case that the light for the second display image is projected.

### Claim 18 (depends on 17)

The display method according to claim 17, further comprising:
selecting one of display modes, and the display modes including a first distance display mode, a second distance display mode, and a dual-distance display mode.

### Claim 19 (depends on 18)

The display method according to claim 18, wherein in the first distance display mode, the display unit projects the light for the first display image; the image processing unit converts polarization direction of the light for the first display image into the first polarization direction and scatters the light for the first display image to display the first display image at a first distance;
in the second distance display mode, the display unit projects the light for the second display image; the image processing unit converts the polarization direction of the light for the second display image into the second polarization direction and transmits the light for the second display image to display the second display image at a second distance; and
in the dual-distance display mode, the display unit projects the light for the first display image and the light for the second display image alternatively, and the image processing unit displays the first display image and the second display image at the first distance and the second distance respectively.

### Claim 20 (depends on 1)

A head-up display apparatus comprising the display apparatus according to claim 1.