DISPLAY DEVICE, DISPLAY SYSTEM, VIDEO OUTPUT DEVICE, AND DISPLAY DEVICE CONTROL METHOD

• US 20160117970A1
• Filed: 05/31/2013
• Published: 04/28/2016
• Est. Priority Date: 05/31/2013
• Status: Active Grant

• Current Assignee: Sharp NEC Display Solutions, Ltd.
• Original Assignee: NEC Display Solutions, Ltd. (NEC Corporation)
• Inventors: Matsui, Katsuyuki
• Granted Patent: US 9,779,648 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/048 using evaluation of the usage time
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/08 Arrangements within a display terminal for setting, manually or automatically, display parameters of the display terminal
• CPC Class Codes: G09G 2360/14 Detecting light within display terminals, e.g. using a single or a plurality of photosensors
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 9/73 Colour balance circuits, e.g. white balance circuits or colour temperature control camera processing pipelines for colour balance H04N23/88
• CPC Class Codes: H04N 9/77 Circuits for processing the brightness signal and the chrominance signal relative to each other, e.g. adjusting the phase of the brightness signal relative to the colour signal, correcting differential gain or differential phase circuits for matrixing H04N9/67

Abstract

A display device includes: a generating unit that generates display chromaticity based on a degradation value, a set chromaticity and device chromaticity, the display chromaticity being chromaticity of a white point to be displayed on the display device, the degradation value indicating a degree of degradation of a backlight, the set chromaticity being chromaticity of a white point based on user setting, the device chromaticity being chromaticity of a white point at which brightness becomes highest in the display device. The generating unit makes the display chromaticity approach the device chromaticity from the set chromaticity, as the degree of degradation indicated by the degradation value increases.

Claims

1. A display device comprising:

a generating unit that generates display chromaticity based on a degradation value, a set chromaticity and device chromaticity, the display chromaticity being chromaticity of a white point to be displayed on the display device, the degradation value indicating a degree of degradation of a backlight, the set chromaticity being chromaticity of a white point based on user setting, the device chromaticity being chromaticity of a white point at which brightness becomes highest in the display device,

wherein the generating unit makes the display chromaticity approach the device chromaticity from the set chromaticity, as the degree of degradation indicated by the degradation value increases.

2. The display device according to claim 1, wherein the generating unit increases a color difference between the set chromaticity and the display chromaticity and decreases a color difference between the device chromaticity and the display chromaticity, as the degree of degradation increases, to generate the display chromaticity.

3. The display device according to claim 1, further comprising:

a video signal adjusting unit that adjusts a gain of a video signal or a drive value for driving the backlight, based on the display chromaticity generated by the generating unit.

4. The display device according to claim 1, wherein the generating unit uses, as the device chromaticity, a value calculated based on at least one of:

a predetermined fixed value;

an operating time of the backlight;

chromaticity of the backlight for when the backlight emits light with a predetermined drive value; and

a drive value for when the backlight is driven so as to have predetermined brightness.

5. The display device according to claim 1, wherein the generating unit uses, as the degradation value, a value is calculated based on at least one of:

a difference or ratio between an initial value and a current value of a drive value for driving the backlight;

a difference or ratio between an initial value and a current value of chromaticity of the backlight;

a difference or ratio between an initial value and a current value of brightness of the backlight; and

an operating time of the backlight from an initial state until present.

6. The display device according to claim 1, wherein the generating unit uses, as the degradation value, a value approaching 0 from 1 with an increase of the degree of degradation, and generates the display chromaticity by using a following expression:

the degradation value×

the set chromaticity+(1−

the degradation value)×

the device chromaticity.

7. A display system comprising a display device and a video output device, wherein

the display device includes:

a backlight that includes a light source; and

a drive unit that drives the backlight,

the video output device includes;

a generating unit that generates display chromaticity based on a degradation value, a set chromaticity and device chromaticity, the display chromaticity being chromaticity of a white point to be displayed on the display device, the degradation value indicating a degree of degradation of the backlight, the set chromaticity being chromaticity of a white point based on user setting, the device chromaticity being chromaticity of a white point at which brightness becomes highest in the display device; and

a video signal adjusting unit that adjusts a gain of a video signal or a drive value for driving the backlight, based on the display chromaticity generated by the generating unit, and

the generating unit makes the display chromaticity approach the device chromaticity from the set chromaticity, as the degree of degradation indicated by the degradation value increases.

8. A video output device comprising:

a generating unit that generates display chromaticity based on a degradation value, a set chromaticity and device chromaticity, the display chromaticity being chromaticity of a white point to be displayed on a display device, the degradation value indicating a degree of degradation of a backlight of the display device, the set chromaticity being chromaticity of a white point based on user setting, the device chromaticity being chromaticity of a white point at which brightness becomes highest in the display device;

a video signal adjusting unit that adjusts a gain of a video signal or a drive value for driving the backlight based on the display chromaticity generated by the generating unit; and

an output unit that outputs the video signal or the drive value that has been adjusted by the video signal adjusting unit, to the display device,

wherein the generating unit makes the display chromaticity approach the device chromaticity from the set chromaticity, as the degree of degradation indicated by the degradation value increases.

9. A method for controlling a display device, the method comprising:

generating display chromaticity based on a degradation value, a set chromaticity and device chromaticity, the display chromaticity being chromaticity of a white point to be displayed on the display device, the degradation value indicating a degree of degradation of a backlight of the display device, the set chromaticity being chromaticity of a white point based on user setting, the device chromaticity being chromaticity of a white point at which brightness becomes highest in the display device; and

adjusting a gain of a video signal or a drive value for driving the backlight based on the display chromaticity generated by the generating,

wherein the display chromaticity is made to approach the device chromaticity from the set chromaticity, as the degree of degradation indicated by the degradation value increases.