# US 11,079,626 B2 · Liquid crystal display device

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- Number: US 11,079,626 B2
- Document ID: US11079626B2
- Status: Granted
- Kind: B2
- Application number: 16/586,624
- Filed: 2019-09-27
- Published: 2020-04-02
- Granted: 2021-08-03
- Earliest claimed: 2018-10-01
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Sharp Kabushiki Kaisha
- Inventors: Yuichi Kawahira; Koji Murata; Takako Koide; Masahiro Hasegawa; Akira Sakai; Kiyoshi Minoura
- Web page: https://patentgrep.com/patent/US11079626B2

## CPC

- G02F 1/133602: {Direct backlight}
- G02F 1/13318: {Circuits comprising a photodetector}
- G02F 1/133502: {Antiglare, refractive index matching layers}
- G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)}
- G09G 5/10: Intensity circuits
- G02F 1/133638: {Waveplates, i.e. plates with a retardation value of lambda/n}
- G09G 2300/02: Composition of display devices
- G09G 2320/064: by time modulation of the brightness of the illumination source
- G09G 2330/021: Power management, e.g. power saving
- G09G 2360/144: the light being ambient light
- 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
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

A liquid crystal display device includes: a liquid crystal panel; a backlight; an illuminance sensor; and a display controller. The liquid crystal panel includes, in order toward the backlight, an antireflection layer, a first linearly polarizing plate, a first λ/4 retardation layer, a first substrate, a second λ/4 retardation layer, a liquid crystal layer, a second substrate, and a second linearly polarizing plate. The liquid crystal panel has a reflectance within a predetermined range in irradiating the liquid crystal panel with light from an antireflection layer side. The liquid crystal display device satisfies a predetermined relation in the following X and Y, where X (unit: lx) is defined as an environmental illuminance detected by the illuminance sensor, and Y (unit: nit) is defined as a luminance of the backlight, adjusted by the display controller.

## Claims

### Claim 1

A liquid crystal display device comprising:
a liquid crystal panel;
a backlight;
an illuminance sensor that detects an environmental illuminance in a surrounding environment of the liquid crystal panel; and
a display controller configured to increase a luminance of the backlight as the environmental illuminance detected by the illuminance sensor increases,
the liquid crystal display device is a transmission liquid crystal display device,
the liquid crystal panel including, in order toward the backlight, an antireflection layer, a first linearly polarizing plate, a first λ/4 retardation layer, a first substrate, a second λ/4 retardation layer, a liquid crystal layer, a second substrate, and a second linearly polarizing plate,
an in-plane slow axis of the first λ/4 retardation layer and a transmission axis of the first linearly polarizing plate forming an angle of 42° to 48°,
the liquid crystal panel having a reflectance of higher than 0% and 0.5% or lower in irradiating the liquid crystal panel with light from an antireflection layer side, and
the liquid crystal display device satisfying 39.002X0.4225≤Y≤220.42X0.2918 with X≥10000, where X (unit: lx) is defined as the environmental illuminance detected by the illuminance sensor, and Y (unit: nit) is defined as the luminance of the backlight, adjusted by the display controller.

### Claim 2 (depends on 1)

The liquid crystal display device according to claim 1, wherein the liquid crystal panel is a liquid crystal panel in a horizontal electric field mode.

### Claim 3

A liquid crystal display device comprising:
a liquid crystal panel;
a backlight;
an illuminance sensor that detects an environmental illuminance in a surrounding environment of the liquid crystal panel; and
a display controller configured to increase a luminance of the backlight as the environmental illuminance detected by the illuminance sensor increases,
the liquid crystal display device is a transmission liquid crystal display device,
the liquid crystal panel including, in order toward the backlight, an antireflection layer, a first linearly polarizing plate, a first λ/4 retardation layer, a first substrate, a second λ/4 retardation layer, a liquid crystal layer, a second substrate, and a second linearly polarizing plate,
an in-plane slow axis of the first λ/4 retardation layer and the transmission axis of the first linearly polarizing plate forming an angle of 42° to 48°,
the liquid crystal panel having a reflectance of higher than 0.5% and 1.3% or lower in irradiating the liquid crystal panel with light from an antireflection layer side, and
the liquid crystal display device satisfying 136.17X0.3891≤Y≤477.54X0.3086 with X≥10000, where X (unit: lx) is defined as the environmental illuminance detected by the illuminance sensor, and Y (unit: nit) is defined as the luminance of the backlight, adjusted by the display controller.

### Claim 4 (depends on 3)

The liquid crystal display device according to claim 3, wherein the liquid crystal panel is a liquid crystal panel in a horizontal electric field mode.

### Claim 5

A liquid crystal display device comprising:
a liquid crystal panel;
a backlight;
an illuminance sensor that detects an environmental illuminance in a surrounding environment of the liquid crystal panel; and
a display controller that adjusts a luminance of the backlight, based on the environmental illuminance detected by the illuminance sensor,
the liquid crystal panel including, in order toward the backlight, an antireflection layer, a first linearly polarizing plate, a first λ/4 retardation layer, a first substrate, a second λ/4 retardation layer, a liquid crystal layer, a second substrate, and a second linearly polarizing plate,
the liquid crystal panel having a reflectance of higher than 1.3% and 1.8% or lower in irradiating the liquid crystal panel with light from an antireflection layer side, and
the liquid crystal display device satisfying 172.05X0.3979≤Y≤640.09X0.3122 with X≥90, where X (unit: lx) is defined as the environmental illuminance detected by the illuminance sensor, and Y (unit: nit) is defined as the luminance of the backlight, adjusted by the display controller.

### Claim 6 (depends on 5)

The liquid crystal display device according to claim 5, wherein the liquid crystal panel is a liquid crystal panel in a horizontal electric field mode.