Reducing angular spread in digital image projection

• US 9,503,711 B2
• Filed: 10/19/2012
• Issued: 11/22/2016
• Est. Priority Date: 10/20/2011
• Status: Active Grant

• Current Assignee: IMAX Corporation
• Original Assignee: IMAX Corporation
• Inventors: Iversen, Steen Svendstorp, Bowron, John W.
• Primary Examiner(s): Chowdhury, Sultan
• Assistant Examiner(s): Cruz, Magda
• Application Number:
  US14/351,816
• Publication Number:
  US 20140300708A1
• Time in Patent Office: 1,495 Days
• US Class Current: 1/1
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration
• CPC Class Codes: G03B 21/147 Optical correction of image distortions, e.g. keystone
• CPC Class Codes: G03B 21/567 for colour projection G03B21/58, G03B21/60 take precedence
• CPC Class Codes: G03B 37/06 involving anamorphosis G03B37/02, G03B37/04 take precedence
• CPC Class Codes: H04N 13/324 Colour aspects
• CPC Class Codes: H04N 13/332 Displays for viewing with the aid of special glasses or head-mounted displays [HMD]
• CPC Class Codes: H04N 13/334 using spectral multiplexing
• CPC Class Codes: H04N 13/363 using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 5/7416 involving the use of a spatial light modulator, e.g. a light valve, controlled by a video signal
• CPC Class Codes: H04N 9/3102 using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• CPC Class Codes: H04N 9/3158 for controlling the spectrum
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129
• CPC Class Codes: H04N 9/317 Convergence or focusing systems electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53
• CPC Class Codes: H04N 9/3182 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 Class Codes: H04N 9/3185 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 Class Codes: H04N 9/3194 including sensor feedback

Abstract

Chromatic aberration can be reduced and extreme projection angles can be allowed in a projection system by modifying one color channel of light having a wavelength bandwidth with image data to produce imaged light, causing the imaged light to spread angularly when displaying the imaged light through an optical distorting element onto a screen, and reducing angular spread of the imaged light exiting the optical distorting element by adjusting the wavelength bandwidth.

Claims

1. A method of digital projection, comprising:

modifying one color channel of light having a wavelength bandwidth with image data to produce imaged light;

causing the imaged light to spread angularly when displaying the imaged light through an optical distorting element onto a screen, wherein the optical distorting element causes an angular color separation of the imaged light; and

reducing angular spread of the imaged light exiting the optical distorting element by adjusting the wavelength bandwidth that reduces the angular color separation of the imaged light appearing on the screen.

2. The method of claim 1, wherein the optical distorting element is a single prism anamorphic adaptor.

3. The method of claim 2, further comprising modifying a magnification of the imaged light in the vertical dimension by the single prism anamorphic adaptor.

4. The method of claim 2, further comprising modifying a magnification of the imaged light in the horizontal dimension by the single prism anamorphic adaptor.

5. The method of claim 1, further comprising:

modifying a second color channel of light with the image data,

wherein the image data is modified to cause the imaged light of at least one color channel exiting the optical distorting element to converge on a screen with imaged light from the second color channel exiting the optical distorting element by a color warping processor.

6. The method of claim 1, further comprising designing into light source emissions a required wavelength bandwidth of light of the at least one color channel.

7. A system for digital projection, the system comprising;

a spatial light modulator adapted for modifying light having a wavelength bandwidth and from at least one color channel with image data to produce imaged light;

a projection lens adapted to project the imaged light; and

a single prism anamorphic adaptor at the output of the projection lens and through which the imaged light is configured to be projected for display on a screen, wherein the single prism anamorphic adaptor is configured for causing the light from the at least one color channel to spread angularly,

wherein the system is adapted for reducing angular spread of the imaged light exiting the optical distorting element by adjusting the wavelength bandwidth.

8. The system of claim 7, further comprising a light source adapted for being designed to include a required wavelength bandwidth into emissions of the light source.

9. The system of claim 8, wherein the light source is a laser light source.

10. The system of claim 9, wherein the laser light source is a laser diode light source.

11. The system of claim 7, further comprising:

a color warping processor adapted for causing the imaged light exiting the single prism anamorphic to converge on the screen with second imaged light from a second color channel exiting the single prism anamorphic adaptor by modifying the image data.

12. The system of claim 7, further comprising the screen, wherein the screen is a dome screen.

13. The system of claim 7, wherein the system is disposed in a dual projector system.

14. The system of claim 7, wherein the spatial light modulator is a 4K spatial light modulator,

wherein the wavelength bandwidth of a light source for one color is configured for being reduced to less than ten nanometers.

15. The system of claim 7, wherein the wavelength bandwidth of a light source is configured for being reduced to less than twenty nanometers.