Transmission type color gradation chart, transmission type color gradation chart device and gray gradation chart

Patent metadata

Field	Value
Publication number	US-12130182-B2
Application number	US-202017768606-A
Country	US
Kind code	B2
Filing date	Oct 12, 2020
Priority date	Oct 15, 2019
Publication date	Oct 29, 2024
Grant date	Oct 29, 2024

Abstract

A transmission type color gradation chart comprising: a color chart member including at least one color bar wherein transmitted light exhibits chromatic color; and a gray gradation chart member wherein transmitted light exhibits achromatic color, and includes a plurality of transmission regions with different brightness, wherein the color chart member and the gray gradation chart member are stacked so that there is a duplicative transmission region wherein the color bar and the plurality of transmission regions overlap in planar view.

First claim

The invention claimed is:

1. A transmission type color gradation chart comprising:
a color chart member including at least one color bar wherein transmitted light exhibits chromatic color; and
a gray gradation chart member wherein transmitted light exhibits achromatic color, and includes a plurality of transmission regions with different brightness,
wherein the color chart member and the gray gradation chart member are stacked so that there is a duplicative transmission region wherein the color bar and the plurality of transmission regions overlap in planar view.

2. The transmission type color gradation chart according to claim 1 , wherein a covered portion in the plurality of transmission regions is formed using a black colorant or a metal.

3. The transmission type color gradation chart according to claim 1 , wherein the plurality of transmission regions is constituted with a dotted region having transmissivity wherein light shielding dots are randomly placed.

4. The transmission type color gradation chart according to claim 1 , wherein a spacer is placed between the color chart member and the gray gradation chart member, and the spacer includes an opening portion in the duplicative transmission region.

5. The transmission type color gradation chart according to claim 1 , wherein a field angle determination mark for determining a field angle of an imaging device to be calibrated by the transmission type color gradation chart, is formed on a main surface, different from a gray gradation chart member side main surface, of the color chart member.

6. The transmission type color gradation chart according to claim 1 , wherein a distance between the adjacent transmission regions in the plurality of transmission regions is a half or more of the width of the transmission region.

7. A transmission type color gradation chart device comprising:
two protective substrates; and
the transmission type color gradation chart according to claim 1 sandwiched between the two protective substrates.

8. A gray gradation chart comprising stacked gray gradation chart structures including a plurality of transmission regions with different brightness placed therein so that the plurality of transmission regions overlap in planar view, and
the plurality of transmission regions is constituted with a dotted region having transmissivity wherein light shielding dots are randomly placed.

9. The gray gradation chart according to claim 8 , wherein a distance between the adjacent dotted regions is a half or more of the width of the dotted region.

10. A method for color calibrating an imaging device, the method comprises:
preparing a transmission type color gradation chart including a color chart member including at least one color bar wherein transmitted light exhibits chromatic color, and a gray gradation chart member wherein transmitted light exhibits achromatic color, and includes a plurality of transmission regions with different brightness, wherein the color chart member and the gray gradation chart member are stacked so that there is a duplicative transmission region wherein the color bar and the plurality of transmission regions overlap in planar view; a lighting equipment; and an imaging device;
photographing an image of the transmission type color gradation chart, with the imaging device, from one surface side of the transmission type color gradation chart by irradiating light, using the lighting equipment as a light source, from another surface side of the transmission type color gradation chart; and
color calibrating the imaging device based on the photographed image photographed with the imaging device.

11. The method for color calibrating an imaging device according to claim 10 , wherein, in the transmission type color gradation chart, the color chart member is placed on the imaging device side.

Assignees

• Dainippon Printing Co Ltd

Inventors

• Maeda Akihiro
• Ogino Yoshihiko
• Kajimura Yoichi

Classifications

• G01J3/52 Primary

  using colour charts · CPC title

• H04N23/88

  for colour balance, e.g. white-balance circuits or colour temperature control · CPC title

• H04N23/86

  for controlling the colour saturation of colour signals, e.g. automatic chroma control circuits · CPC title

• H04N23/841

  to modify gamut · CPC title

• H04N23/83 Primary

  specially adapted for colour signals · CPC title