Optical system designs for generation of light fields using spatial light modulators

Patent metadata

Field	Value
Publication number	US-2016373701-A1
Application number	US-201615185699-A
Country	US
Kind code	A1
Filing date	Jun 17, 2016
Priority date	Jun 17, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

In described examples, a method of creating multiple light images uses spatially-separated light sources, arranged in an array, operated in multiplexed fashion, for driving a spatial light modulator. Each of the light sources is time-sequenced to direct light at the spatial light modulator during a predetermined time interval. The spatial light modulator is synchronized with the light sources and controlled to produce a desired image during each time interval. The resulting images are received by an optical lens system to provide light images along an image plane. Alternately, the optical lens system focuses the modulated light images on a hogel plane to produce a light field. The pixel count of the spatial light modulator is effectively multiplied by the number of light sources. Each light source may sequentially provide multiple colors to produce a full-color image. The light source array may, in turn, be driven by one or more remotely-located master light sources.

First claim

What is claimed is:

1 . A method of using a spatial light modulator to create multiple light images over a display cycle, the display cycle being divided into a plurality of time intervals, the method comprising:
providing a plurality of spatially-separated light source elements; providing a spatial light modulator; alternately selecting at least one of the plurality of light source elements to be operable during a corresponding time interval; directing light from the selected at least one light source element at the spatial light modulator; controlling the spatial light modulator to emit a predetermined light image during each time interval; and providing a plurality of spatially-separated lenses equal in number to the number of light source elements within the plurality of light source elements, each of such plurality of lenses receiving the predetermined light image emitted by the spatial light modulator during a corresponding time interval; wherein the plurality of lenses provide a corresponding plurality of light images along an image plane over a plurality of time intervals in each display cycle, while providing at least one light image during any particular time interval.

2 . The method of claim 1 , further comprising: synchronizing the selection of the plurality of light source elements with controlling the spatial light modulator.

3 . The method of claim 1 , wherein the spatial light modulator provides a predetermined number of pixels for each light source element during each time interval, and wherein the spatial light modulator provides a cumulative total of pixels during each display cycle equal to the number of light source elements multiplied by the predetermined number of pixels.

4 . The method of claim 1 , further comprising: providing a projection lens for receiving the plurality of light images provided along the image plane, magnifying such light images, and projecting such light images to form a high resolution image on a display surface.

5 . The method of claim 1 , further comprising: providing a projection lens for receiving the plurality of light images provided along the image plane, magnifying such light images, and projecting such light images upon a work surface.

6 . The method of claim 1 , wherein the spatial light modulator is a digital micromirror device.

7 . The method of claim 1 , wherein the plurality of spatially-separated light source elements are arranged in a two-dimensional array.

8 . The method of claim 7 , wherein the plurality of spatially-separated lenses are arranged in a two-dimensional array.

9 . The method of claim 1 , wherein each of the spatially-separated light source elements is adapted to provide a plurality of different colors at different times, and wherein each such light source element is operated to provide light of a first color during one time interval and light of a second color during a second time interval.

10 . The method of claim 1 , further comprising:
providing a transparent plate between the spatial light modulator and the plurality of spatially-separated lenses, the transparent plate having an index of refraction, the transparent plate being movable along a first axis between a first position relative to the spatial light modulator, and a second position relative to the spatial light modulator, for selectively refracting light rays passing from the spatial light modulator to the spatially-separated lenses; selecting at least one of the plurality of light source elements to be operable during first and second time intervals; directing light from the selected at least one light source element at the spatial light modulator during both the first and second time intervals; disposing the transparent plate at the first position during the first time interval, and controlling the spatial light modulator to emit a first group of light rays during the first time interval, for passage by the transparent plate with a lesser amount of refraction; and disposing the transparent plate at the second position during the second time interval, and controlling the spatial light modulator to emit a second group of light rays during the second time interval, for passage by the transparent plate with a greater amount of refraction.

11 . The method of claim 10 , wherein the transparent plate is also movable along a second axis relative to the spatial light modulator, the second axis lying orthogonal to the first axis.

12 . The method of claim 1 , further comprising:
providing a mirror between the spatial light modulator and the plurality of spatially-separated lenses, the mirror being movable along a first axis between a first angular position relative to the spatial light modulator, and a second angular position relative to the spatial light modulator, for reflecting light rays passing from the spatial light modulator to the spatially-separated lenses; selecting at least one of the plurality of light source elements to be operable during first and second time intervals; directing light from the selected at least one light source element at the spatial light modulator during both the first and second time intervals; disposing the mirror at the first position during the first time interval, and controlling the spatial light modulator to emit a first group of light rays during the first time interval, for reflection by the mirror at a first angle; and disposing the mirror at the second position during the second time interval, and controlling the spatial light modulator to emit a second group of light rays during the second time interval, for reflection by the mirror at a second angle.

13 . The method of claim 12 , wherein the mirror is also movable along a second axis relative to the spatial light modulator, the second axis lying orthogonal to the first axis.

14 . A method of creating light hogels within a light field display over a display cycle, the display cycle being divided into a plurality of time intervals, the method comprising:
providing a plurality of spatially-separated light source elements; providing a spatial light modulator; alternately selecting at least one of the plurality of light source elements to be operable during a corresponding time interval; directing light from the selected at least one light source element at the spatial light modulator; controlling the spatial light modulator to emit predetermined light rays during each time interval; and providing a lens element for receiving the predetermined light rays emitted by the spatial light modulator during a corresponding time interval, the lens element focusing received rays of light onto a hogel plane to provide a predetermined light hogel during each time interval, the predetermined light hogel having a location within the hogel plane corresponding to a location of the at least one light source element selected during a respective time interval; wherein a plurality of light hogels are provided along the hogel plane over a plurality of time intervals in each display cycle, while providing at least one hogel during any particular time interval.

15 . The method of claim 14 , further comprising: providing a mask with a plurality of apertures at the hogel plane, the apertures permitting light rays to pass therethrough while reducing passage of stray light and defining dimensions of each light hogel.

16 . The method of claim 14 , further comprising: synchronizing the selection of the plurality of light source elements with controlling the spatial light modulator.

17 . The method of claim 14 , wherein the spatia

Assignees

• Texas Instruments Inc

Inventors

• Ferri John Marshall
• Pettitt Gregory Scott

Classifications

• H04N9/312 Primary

  Driving therefor (driving of electronic spatial light modulators in displays other than projection devices G09G3/34, G09G3/36; control of liquid crystal elements G02F1/133; control of micromechanical modulators G02B26/08) · CPC title

• G03B35/16

  by sequential viewing · CPC title

• G03B21/005

  Projectors using an electronic spatial light modulator but not peculiar thereto · CPC title

• H04N13/32

  using arrays of controllable light sources; using moving apertures or moving light sources · CPC title

• H04N9/3161

  using laser light sources (using laser beams scanning the display screen H04N9/3129) · CPC title