Image projection apparatus and control method therefor

Patent metadata

Field	Value
Publication number	US-9262995-B2
Application number	US-201114353010-A
Country	US
Kind code	B2
Filing date	Dec 20, 2011
Priority date	Dec 20, 2011
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

The image projection apparatus of the present invention includes a light source that outputs coherent light; a phase modulator that performs phase modulation on the light output from the light source to create a Fourier transform image; an amplitude modulator that performs amplitude modulation on the Fourier transform image in accordance with an image signal; a projection optical system that projects the light that has been amplitude modulated, and a controller that divides the image represented by the image signal into a plurality of divided images, determines the target luminance value of each of the areas of the Fourier transform image that is divided corresponding to the division of the image, based on the image signal, and outputs phase data indicating the amount of phase modulation so as to make the luminance value of each area of the Fourier transform image acquire the target luminance value of the associated area.

First claim

What is claimed is:

1. An image projection apparatus for projecting an image represented by an input image signal, comprising:
a light source that outputs coherent light;
a phase modulator that performs phase modulation on the light output from said light source to create a Fourier transform image;
an amplitude modulator that performs amplitude modulation on the Fourier transform image in accordance with said image signal;
a projection optical system that projects the light that has been amplitude modulated by said amplitude modulator; and,
a controller that divides the image represented by the image signal into a plurality of divided images, determines a target luminance value of each of areas of the Fourier transform image that is divided corresponding to the division of the image, based on said image signal of the divided image corresponding to an area, and outputs phase data indicating an amount of phase modulation on the output light from said light source so as to make a luminance value of each area of the Fourier transform image acquire the target luminance value of the associated area.

2. The image projection apparatus according to claim 1 , wherein said controller controls the driving of said light source based on the target luminance value of each area of the Fourier transform image.

3. The image projection apparatus according to claim 1 , wherein said controller controls the driving of the amplitude modulator based on the target luminance value of each area of the Fourier transform image.

4. The image projection apparatus according to claim 1 , wherein
said controller stores in association with a light intensity profile that indicates the target luminance values of the individual areas of the Fourier transform image and the phase data that makes the luminance value of each area of the Fourier transform image acquire the target luminance value of each area indicated by the light intensity profile, determines the light intensity profile corresponding to said image signal, from the stored light intensity profiles, and outputs the phase data being stored in association with the determined light intensity profile, to said phase modulator.

5. The image projection apparatus according to claim 1 , wherein said controller divides one frame of an image represented by said image signal into a plurality of subframes, and determines the target luminance value of each area in the Fourier transform image, on a subframe basis.

6. The image projection apparatus according to claim 1 , wherein a plurality of said light sources are provided, and said phase modulator performs phase modulation on the light output from each of said plural light sources and radiates the light beams that have been output from said plural light sources and that has been phase modulated, onto different areas of said amplitude modulator.

7. The image projection apparatus according to claim 1 , wherein the phase modulator comprises a hologram.

8. A control method for an image projection apparatus that includes a light source that outputs coherent light to project an image represented by an input image signal by modulating the light output from said light source in accordance with said image signal, comprising:
performing phase modulation on the light output from said light source to create a Fourier transform image;
performing amplitude modulation on the Fourier transform image in accordance with said image signal; and
projecting the amplitude-modulated light, wherein the phase modulation is performed by dividing the image represented by said image signal into a plurality of divided images, determining a target luminance value of each of areas of the Fourier transform image that is divided corresponding to the division of the image, based on the image signal in the divided image corresponding to an area so as to make a luminance value of each area of the Fourier transform image acquire the target luminance value of the associated area.

Assignees

• Fujioka Nobuhide
• Nec Display Solutions Ltd

Inventors

• Fujioka Nobuhide

Classifications

• G02B27/1066 Primary

  for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view · CPC title

• G02B27/149

  using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes · 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

• G02B26/06

  for controlling the phase of light (G02B26/08 takes precedence {, measuring optical phase difference G01J9/00}) · CPC title

• H04N9/3155

  for controlling the light source (light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406) · CPC title