Image projection apparatus

Patent metadata

Field	Value
Publication number	US-10921701-B2
Application number	US-201816207554-A
Country	US
Kind code	B2
Filing date	Dec 3, 2018
Priority date	Dec 22, 2017
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

An image projection apparatus includes: a projector; a projection control apparatus; and a color tone sensor. The projector projects an image. The projection control apparatus causes the projector to perform a projection on a surface of a target serving as a projection target. The color tone sensor detects a color tone of the surface of the target on which an image is projected. The projection control apparatus adjusts a color tone of an image to be projected on a basis of a detection result of the color tone sensor such that the color tone detected by the color tone sensor has a predetermined value.

First claim

The invention claimed is:

1. An image projection apparatus comprising:
a projector configured to project an image;
a projection control apparatus configured to cause the projector to perform a projection on a surface of a target serving as a projection target; and
a color tone sensor configured to repeatedly detect a color tone of the projected image on the surface of the target,
wherein the projection control apparatus performs color tone adjustment in an iteration process in which:
the projection control apparatus repeatedly compares a target color with each detected color tone to determine a difference between the target color and the detected color tone, and repeatedly changes a color tone of a projection light based on the determined difference, until the target color agrees with the detected color tone, and wherein the projection control apparatus is configured to:
generate projection data to be projected on the surface by calibrating a shape that is indicated in the image according to a shape of a curved surface of the target and a position of the projector in relation to the target, and
cause the projector to perform the projection on the surface in accordance with the projection data.

2. The image projection apparatus of claim 1 , wherein the projection control apparatus repeatedly compares an intensity of respective components of RGB in the target color with an intensity of respective components of RGB in each detected color tone to determine an RGB intensity difference, and repeatedly changes the color tone of the projection light based on the determined RGB intensity difference, until the target color agrees with the detected color tone.

3. The image projection apparatus according to claim 1 , wherein the projection control apparatus is configured to:
divide the image into lattice, and
generate the projection data by calibrating a shape that is indicated in the divided image according to a shape of the curved surface where the divided image is projected on.

4. The image projection apparatus according to claim 3 , comprising:
a first projector configured to irradiate a first surface of the target with a first projection light, and
a second projector configured to irradiate a second surface other than the first surface of the target with a second projection light,
wherein the projection control apparatus is configured to cause the first projection light of the first projector and the second projection light of the second projector to be combined to display the image on a whole surface of the target.

5. The image projection apparatus according to claim 4 , wherein the first projection light of the first projector and the second projection light of the second projector are configured to overlap with each other to display the image.

6. The image projection apparatus according to claim 5 , wherein the projection control apparatus is configured to generate:
first projection data to be transmitted to the first projector by blending the first projection data with second projection data of an overlapping area to be transmitted to the second projector, and
second projection data to be transmitted to the second projector by blending the second projection data with the first projection data of the overlapping area.

7. The image projection apparatus of claim 1 , wherein the projection control apparatus is configured to:
compare a balance between respective components of RGB in the target color with a balance between respective components of RGB in each detected color tone,
extract a difference for each component, and
change the color tone of the projection light by the extracted difference.

8. The image projection apparatus of claim 7 , wherein the projection control apparatus is configured to project the projection light of which the color tone is changed by the extracted difference.

9. The image projection apparatus of claim 1 , wherein the projection control apparatus is configured to continuously repeat the following steps until the target color agrees with any color tone detected by the color tone sensor:
acquire a new color tone detected by the color tone sensor,
compare a balance between respective components of RGB in the target color with a balance between respective components of RGB in the new color tone,
extract a difference for each component,
change the color tone of the projection light by the extracted difference, and
project the projection light of which the color tone is changed by the extracted difference.

Assignees

• Subaru Corp

Inventors

• Suzuki Kei
• Murata Iwao
• Nagai Yuichi
• Shibao Yasunori
• Kikuchi Marosuke

Classifications

• H04N9/3147 Primary

  Multi-projection systems (video walls G06F3/1446) · CPC title

• H04N9/3185

  Geometric adjustment, e.g. keystone or convergence (optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14) · CPC title

• H04N9/3188

  Scale or resolution adjustment (scaling in general G06T3/40; resolution modifying circuits for displays in general G09G5/391) · CPC title

• H04N9/3194

  including sensor feedback · CPC title

• H04N9/3182

  Colour adjustment, e.g. white balance, shading or gamut (white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607) · CPC title