US 6,788,469 B2Granted

Automated lamp focus

AssigneeTexas Instruments Incorporated

InventorsDuane Scott Dewald, William B. Werner, Frank J. Poradish

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Abstract

Methods for measuring and automatically controlling the light distribution and overall brightness in electronic-based spatial light modulator projection display systems. One method takes a small fraction of the projected light from a partial turning mirror 407 in the projector's optics path and focuses this light on to a detector 420 for use in controlling the light distribution and brightness of the system. Another method uses an array of embedded light sensors 518-522 at chosen locations on the surface of a display screen 517 to control the light distribution and brightness parameters of the projection system. Both methods use a micro-controller, servomotors, and an adjustable power supply, controlled by the detector/sensor outputs, to maintain the desired light distribution and brightness in the projected image.

Claims22

Dependent claims

An optics/controller sub-assembly for automated focus and brightness control in a spatial light modulator projection system, comprising:

a lamp/reflector providing white light along a first light path, said light brought to a focus point at the entrance to a light integrator;
a first relay lens receiving light from said light integrator and sizing said light to the entrance of a second group of relay lenses;
light from said relay lenses continuing along said first light path, striking the surface of a partial folding mirror;
primary light reflecting off said partial folding mirror along a second light path and partial light passing through said partial folding mm-or exiting along a third light path;
a third relay lens placed in said second light path, receiving said reflected primary light from said partial folding mirror and resizing said light to match said system's total internal reflective prism;
light passing through said total internal reflective prism to red-green-blue splitting prisms;
spatial light modulators positioned to receive said red-green-blue light, respectively, from said color prisms, said light being modulated and reflected from said respective spatial light modulators into recombining optics, through a projection lens, and on to a display screen;
a third relay lens located in said third light path, receiving said partial light passing trough said partial folding mirror, sizing, and directing said light on to the surface of secondary folding mirror;
a light detector receiving said reflected light from said secondary folding minor, a micro-controller coupled to the output of said detector;
first, second, and third outputs from said micro-controller coupled to lamp x, y, z focus servomotors, respectively;
a fourth output from said micro-controller coupled to a lamp power supply;
and
a fifth output from said micro-controller to enable a maintenance notification function.

10 more elements

A spatial light modulator based electronic projection system with automated lamp focus control, comprising:

a light source emitting light along a first light path;
a light integrator on said first light path receiving said light;
a first relay lens directing light from said integrator to a second series of relay lenses and on to the surface of a partial turning mirror;
primary light reflected from said partial turning mirror directed along a second light path through a third relay lens and through a total internal reflective prism on to the surface of red-green-blue color splitting prisms, respectively;
three spatial light modulators positioned to receive red-green-blue light, respectively, from said color prisms;
modulated light reflected from said spatial light modulators directed through recombining optics and projected by means of a projection lens, on to a display screen;
secondary light passing through said partial turning minor directed along a third light path, through a focusing lens and reflecting off a secondary turning mirror onto the surface of a light detector,
a micro-controller coupled to the output of said light detector, wherein the output of said light detector is used to control the brightness and light distribution of said light source.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/039,127Filed 31 Dec 2001 · us provisional application
Priority: 30 Dec 2000
Published: US 2002/0085288 A14 Jul 2002
Granted: 7 Sep 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H04N 9/3105
Using two-dimensional electronic spatial light modulators: for displaying all colours simultaneously, e.g. by using two or more electronic spatial…
H04N 9/3155
Modulator illumination systems: for controlling the light source
H04N 9/3194
Testing thereof: including sensor feedback
H04N
Pictorial communication