Imaging system

• US 4,728,185 A
• Filed: 02/20/1987
• Issued: 03/01/1988
• Est. Priority Date: 07/03/1985
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Thomas, David A.
• Primary Examiner(s): HAROIAN, HARRY
• Application Number:
  US07/018,795
• Time in Patent Office: 375 Days
• Field of Search: 353/121, 353/122, 358/233, 350/360, 350/359
• US Class Current: 353/122
• CPC Class Codes: H04N 1/036 for optical reproduction

Abstract

Optical systems for imaging activated pixels of a linear cantilever beam light valve (14) on a receptor or screen (24) are disclosed. The systems include a light source (12), a condenser lens (16) and pupil mask (26) forming a beam (32) from the output of the light source (12), a relay lens (18) for the beam (32) to image the pupil mask (26) onto the linear cantilever beam light valve (14), and an imaging lens (22) with an optional iris diaphragm (50) for imaging the portion of the beam (32) reflected from activated pixels of the light valve (14) onto the receptor or screen (24) while blocking the portion of the beam (32) reflected or diffracted from the remainder of the light valve (14).

Claims

1. An optical system for a light valve, comprising:

(a) a source of light;

(b) a lens system, said lens system directing a beam of light from said source onto a light valve;

(c) said light valve reflecting said beam, with the portion of said reflected beam unmodulated by said light valve forming an image of said source plus diffraction orders at a first region in a plane and with the portion of said reflected beam modulated by said light valve forming an image of said source at a second region in said plane, said first and second regions disjoint; and

(d) an imaging system located at said plane, said imaging system imaging said light valve onto a receptor with said reflected beam.

2. The optical system of claim 1, wherein:

(a) said imaging system included an imaging lens in said plane and centered at said second region and disjoint from said first region.

3. The optical system of claim 2, wherein:

(a) said first region is cross-shaped with each cross arm a plurality of circular regions linearly arranged;

(b) said second region is circular and centered on a line through the center of said cross-shaped first region and at an angle of 45°

to the cross arms; and

(c) said imaging lens has a pupil approximately equal to said second region.

4. The optical system of claim 1, wherein:

(a) said imaging system includes an imaging lens in said plane and centered at said second region and with an iris diaphragm disjoint from said first region.

5. The optical system of claim 4, wherein:

(a) said first region is cross-shaped with each cross arm a plurality of circular regions linearly arranged;

(b) said second region is circular and centered on a line through the center of said cross-shaped first region and at an angle of 45°

to the cross arms; and

(c) said imaging lens has said iris diaphragm approximately equal to said second region.

6. The optical system of claim 1, wherein:

(a) said imaging system included an imaging lens in said plane and centered at said first region.

7. The optical system of claim 6, wherein:

(a) said first region is cross-shaped with each cross arm a plurality of circular regions linearly arranged with a common circular region at the crossing of the cross arms;

(b) said second region has a plurality of subregions, each of said subregions is circular and centered on a line through the center of said cross-shaped first region and at an angle of 45°

to the cross arms; and

(c) said imaging lens has a pupil approximately equal to the said common circular region of said first region.

8. The optical system of claim 8, wherein:

(a) said imaging system includes an imaging lens in said plane and centered at said second region and with said light valve centered on the optic axis of said imaging lens.

9. The optical system of claim 8, wherein:

(a) said lens system includes;

(i) a condenser lens for said source, (ii) a pupil mask for said condenser lens to define said beam, (iii) a source mask in said beam and conjugate to said source by said condenser lens, and (iv) a relay lens directing said beam onto said light valve and imaging said source mask onto said plane.