# US 12,001,089 B2 · Display system and vehicle

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- Number: US 12,001,089 B2
- Document ID: US12001089B2
- Status: Granted
- Kind: B2
- Application number: 18/336,246
- Filed: 2023-06-16
- Published: 2023-10-12
- Granted: 2024-06-04
- Earliest claimed: 2020-04-28
- Assignees: Japan Display Inc.
- Applicants: Japan Display Inc.
- Inventors: Toshiharu Matsushima
- Web page: https://patentgrep.com/patent/US12001089B2

## CPC

- G02F 1/1323: {Arrangements for providing a switchable viewing angle}
- B60K 35/22: Display screens
- B60K 35/415: {Glare prevention}
- G02F 1/13318: {Circuits comprising a photodetector}
- G02F 1/133528: {Polarisers}
- G02F 1/13471: {in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells (G02F1/13475 takes precedence)}
- B60K 35/00: Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
- B60K 35/658: {the instruments being ergonomically adjustable to the user}
- B60K 35/81: for controlling displays
- B60K 2360/1523: Matrix displays
- 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
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES

## Abstract

According to one embodiment, a display system includes an external light sensor, a display panel, a viewing angle control panel including a liquid crystal layer containing liquid crystal molecules twist-aligned, configured such that a drive voltage applied to the liquid crystal layer is controlled based on an external light intensity detected by the external light sensor, and a polarization axis rotation element disposed between the viewing angle control panel and the display panel. The drive voltage when the external light intensity is less than a threshold value is greater than the drive voltage when the external light intensity is greater or equal to than the threshold value.

## Claims

### Claim 1

A display system comprising:
an optical light sensor detecting a light intensity;
a display panel;
a first polarizer disposed on a front side of the display panel;
a viewing angle control panel comprising a liquid crystal layer containing liquid crystal molecules twist-aligned; and
a polarization axis rotation element disposed between the viewing angle control panel and the display panel, and rotating a polarization axis of light transmitted through the viewing angle control panel, wherein
the liquid crystal molecules twist-aligned include an alignment direction which is substantially parallel to a first transmission axis of the first polarizer,
the viewing angle control panel is configured that a luminance of a transmitted light in the alignment direction decreases as a drive voltage applied to the liquid crystal layer increases,
in a first mode which the light intensity is less than or equal to a threshold value, the drive voltage is set to a first voltage,
in a second mode which the light intensity is greater than the threshold value, the drive voltage is set to a second voltage, and
the first voltage is different from the second voltage.

### Claim 2 (depends on 1)

The display system of claim 1, further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element in the first mode is equal to the luminance level of the light-emitting element in the second mode.

### Claim 3 (depends on 1)

The display system of claim 1, further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element in the first mode is greater than the luminance level of the light-emitting element in the second mode.

### Claim 4 (depends on 1)

The display system of claim 1, further comprising:
a second polarizer disposed between the display panel and the polarization axis rotation element; and
a third polarizer disposed between the polarization axis rotation element and the viewing angle control panel, wherein
the second polarizer has a second transmission axis,
the third polarizer has a third transmission axis, and
the polarization axis rotation element is configured to impart a retardation of ½ wavelength to a transmitted light, and has an optical axis in a direction halfway between a direction of the second transmission axis and a direction of the third transmission axis.

### Claim 5

A vehicle comprising:
a front window disposed in a front part of the vehicle;
a driver seat and a passenger seat;
a display device; and
an optical light sensor detecting a light intensity, wherein
the display device comprises:
a display panel;
a first polarizer disposed on a front side of the display panel; and
a viewing angle control panel comprising a liquid crystal layer containing liquid crystal molecules twist-aligned, and
the liquid crystal molecules twist-aligned include an alignment direction which is substantially parallel to a first transmission axis of the first polarizer,
the viewing angle control panel is configured that a luminance of a transmitted light in the alignment direction decreases as a drive voltage applied to the liquid crystal layer increases,
in a first mode which the light intensity is less than or equal to a threshold value, the drive voltage is set to a first voltage,
in a second mode which the light intensity is greater than the threshold value, the drive voltage is set to a second voltage, and
the first voltage is different from the second voltage.

### Claim 6 (depends on 5)

The vehicle of claim 5, wherein
the driver seat and the passenger seat are arranged in a first direction, and
the alignment direction is substantially orthogonal to the first direction.

### Claim 7 (depends on 5)

The vehicle of claim 5, further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element in the first mode is equal to the luminance level of the light-emitting element in the second mode.

### Claim 8 (depends on 5)

The vehicle of claim 5, further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element in the first mode is greater than the luminance level of the light-emitting element in the second mode.

### Claim 9 (depends on 5)

The vehicle of claim 5, further comprising a polarization axis rotation element disposed between the viewing angle control panel and the display panel, and configured to rotate a polarization axis of light transmitted through the viewing angle control panel.

### Claim 10 (depends on 9)

The vehicle of claim 9, further comprising:
a second polarizer disposed between the display panel and the polarization axis rotation element; and
a third polarizer disposed between the polarization axis rotation element and the viewing angle control panel, wherein
the second polarizer has a second transmission axis,
the third polarizer has a third transmission axis, and
the polarization axis rotation element is configured to impart a retardation of ½ wavelength to a transmitted light, and has an optical axis in a direction halfway between a direction of the second transmission axis and a direction of the third transmission axis.