Method of adjusting white balance, white balance adjustment apparatus, and display device

Patent metadata

Field	Value
Publication number	US-10229624-B2
Application number	US-201815888108-A
Country	US
Kind code	B2
Filing date	Feb 5, 2018
Priority date	Feb 22, 2017
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

A shift amount between a measurement value of a color value of white color and a calculation value of the color value of white color is calculated. Generated is a math formula in which the shift amount is reflected. Calculated is gradation values after the WB adjustment which the gradation values after the correction take in a case where the calculation value of the color value of the displayed color is a target color value of white color in the math formula. Contents of the WB correction are adjusted so that the gradation values after the correction is adjusted to be the gradation values after the WB adjustment in the case where the gradation values before the correction are specific gradation values.

First claim

What is claimed is:

1. A method of adjusting white balance, comprising:
a) acquiring a measurement value of a color value of white color, in a display device performing a white balance correction of correcting first to n th gradation values before a correction to be first to n th gradation values after the correction and displaying a displayed color in accordance the first to n th gradation values after the correction, n indicating an integral number of three or larger, in a case where the first to n th gradation values after the correction are first to n th specific gradation values for making the display device display white color, respectively, and the displayed color is white color;
b) calculating a shift amount between the measurement value of the color value of white color and a calculation value of a color value of white color derived from the first to n th specific gradation values;
c) performing a generation of a math formula for deriving a calculation value of a color value of a displayed color from the first to n th gradation values after the correction, the reflection of the shift amount being performed on the math formula so that the calculation value of a color value of a displayed color is brought close to a measurement value of a color value of a displayed color;
d) calculating first to n th gradation values after a white balance adjustment which the first to n th gradation values after the correction take, respectively, in a case where the calculation value of the color value of the displayed color is a target color value of white color in the math formula; and
e) adjusting contents of the white balance correction so that the first to n th gradation values after the correction are adjusted to the first to n th gradation values after the white balance adjustment, respectively, in a case where the first to n th gradation values before the correction are the first to n th specific gradation values, respectively.

2. The method of adjusting white balance according to claim 1 , wherein
the shift amount includes contribution of all the first to n th specific gradation values,
the math formula includes first to n th coefficients respectively indicating degrees of contribution of the first to n th gradation values after the correction to the calculation value of the color value of the displayed color, and
the reflection is performed by dividing the shift amount into first to n th correction amounts, respectively corresponding to contribution rates of the first to n th specific gradation values contributing to the correction amount, and respectively setting the first to n th correction amounts to be factors included in the first to n th coefficients.

3. The method of adjusting white balance according to claim 2 , wherein
the generation is performed by estimating an estimated shift amount between a measurement value of a color value of white color after the step e) is executed and a calculation value of a color value of white color derived from the first to n th specific gradation values, and then reducing the estimated shift amount.

4. The method of adjusting white balance according to claim 1 , wherein
the generation is performed by estimating an estimated shift amount between a measurement value of a color value of white color after the step e) is executed and a calculation value of a color value of white color derived from the first to n th specific gradation values, and then reducing the estimated shift amount.

5. A white balance adjustment apparatus, comprising:
a white color measurement value acquisition unit to acquire a measurement value of a color value of white color, in a display device performing a white balance correction of correcting first to n th gradation values before a correction to be first to n th gradation values after the correction and displaying a displayed color in accordance the first to n th gradation values after the correction, n indicating an integral number of three or larger, in a case where the first to n th gradation values after the correction are first to n th specific gradation values for making the display device display white color, respectively, and the displayed color is white color;
a shift amount calculation unit to calculate a shift amount between the measurement value of the color value of white color and a calculation value of a color value of white color derived from the first to n th specific gradation values;
a math formula generation unit to perform a generation of a math formula for deriving a calculation value of a color value of a displayed color from the first to n th gradation values after the correction, the reflection of the shift amounts being performed on the math formula so that the calculation value of a color value of a displayed color is brought close to a measurement value of a color value of a displayed color;
a gradation value calculation unit to calculate first to n th gradation values after a white balance adjustment which the first to n th gradation values after the correction take, respectively, in a case where the calculation value of the color value of the displayed color is a target color value of white color in the math formula; and
a white balance adjustment unit to adjust contents of the white balance correction so that the first to n th gradation values after the correction are adjusted to the first to n th gradation values after the white balance adjustment, respectively, in a case where the first to n th gradation values before the correction are the first to n th specific gradation values, respectively.

6. A display device, comprising:
a display mechanism performing a white balance correction of correcting first to n th gradation values before a correction to be first to n th gradation values after the correction and displaying a displayed color in accordance the first to n th gradation values after the correction, n indicating an integral number of three or larger;
a white color measurement value acquisition unit to acquire a measurement value of a color value of white color in a case where the first to n th gradation values after the correction are first to n th specific gradation values for making the display mechanism display white color, respectively, and the displayed color is white color;
a shift amount calculation unit to calculate a shift amount between the measurement value of the color value of white color and a calculation value of a color value of white color derived from the first to n th specific gradation values;
a math formula generation unit to perform a generation of a math formula for deriving a calculation value of a color value of a displayed color from the first to n th gradation values after the correction, the reflection of the shift amounts being performed on the math formula so that the calculation value of a color value of a displayed color is brought close to a measurement value of a color value of a displayed color;
a gradation value calculation unit to calculate first to n th gradation values after a white balance adjustment which the first to n th gradation values after the correction take, respectively, in a case where the calculation value of the color value of the displayed color is a target color value of white color in the math formula; and
a white balance adjustment unit to adjust contents of the white balance correction so that the first to n th gradation values after the correction are adjusted to the first to n th gradation values after the white balance adjustment, respectively, in a case where the first to n th gradation values before the correction are the first to n th specific gradation values, respectively.

Assignees

• Mitsubishi Electric Corp
• Mistubishi Electric Corp

Inventors

• Tanaka Shogo

Classifications

• G09G2320/0242

  Compensation of deficiencies in the appearance of colours · CPC title

• G09G3/3677

  suitable for active matrices only · CPC title

• G09G3/3688

  suitable for active matrices only · CPC title

• G09G2320/0276

  for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction · CPC title

• G09G3/2003 Primary

  Display of colours (specific for liquid crystal displays G09G3/3607) · CPC title