Dynamic aperture for display systems

• US 20070133208A1
• Filed: 12/09/2005
• Published: 06/14/2007
• Est. Priority Date: 12/09/2005
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Marshall, Stephen, Smith, Steven
• Application Number:
  US11/298,257
• Publication Number:
  US 20070133208A1
• Time in Patent Office: Days
• US Class Current: 362/284
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G03B 33/08 Sequential recording or projection G03B33/02, G03B33/04, G03B33/06 take precedence
• CPC Class Codes: H04N 9/3155 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

Abstract

System and apparatus for improving the display quality of display systems. A preferred embodiment comprises a planar object configured to variably pass light produced by a light source located on a first side of the planar object to a second side of the planar object, and a motor coupled to the planar object, the motor to rotate the planar object and change the amount of light passed by the planar object. The planar object includes a semi-circular beveled portion formed on a first side of the planar object. A slot with monotonically increasing width is cut along a spine of the semi-circular beveled portion and through the planar object and depending upon a width of the slot that is in front of the light source, the planar object passes a different amount of light. The motor is a DC brushless motor or a limited angular torque motor.

Claims

1. An apparatus comprising:

a planar object having a first side with a semi-circular beveled portion formed near at least a portion of a perimeter of the planar object, the semi-circular beveled portion having a tapered cross-section; and

a slot cut along a spine of the semi-circular beveled portion of the planar object and through the planar object, the slot having an inner edge with an inner radius and an outer edge with an outer radius, wherein at least the inner radius or the outer radius changes with a length of the slot.

2. The apparatus of claim 1, wherein a surface of the tapered cross-section of the semi-circular beveled section along the inner edge recedes from the inner edge and a surface of the tapered cross-section of the semi-circular beveled section along the outer edge of the slot recedes from the outer edge.

3. The apparatus of claim 1, wherein arcs formed by the inner edge of the slot and the outer edge of the slot are Archimedes arcs.

4. The apparatus of the claim 3, wherein a width of the slot changes monotonically along the length of the slot.

5. The apparatus of the claim 3, wherein the radius of the inner edge and the radius of the outer edge of the slot change in a complementary fashion along the length of the slot.

6. The apparatus of claim 1, wherein the disc is made from a metallic material.

7. The apparatus of claim 1, wherein the first side of the disc is coated with a reflective material.

8. A dynamic aperture comprising:

a planar object configured to variably pass light produced by a light source located on a first side of the side of the planar object to a second side of the planar object, wherein the planar object comprises a semi-circular beveled portion formed on a first side of the planar object, the semi-circular beveled portion formed along at least a portion of a perimeter of the planar object; and

a motor coupled to the planar object, the motor configured to rotate the planar object and change the amount of light passed by the planar object.

9. The dynamic aperture of claim 8, wherein the semi-circular beveled portion has a tapered cross-section, and wherein planar object comprises a slot cut along a spine of the semi-circular beveled portion of the planar object and through the planar object, the slot having an inner edge with an inner radius and an outer edge with an outer radius, wherein at least the inner radius or the outer radius changes along with a length of the slot.

10. The dynamic aperture of claim 9, wherein the inner edge of the slot and the outer edge of the slot are Archimedes spirals.

11. The dynamic aperture of claim 8, wherein the planar object is coupled to the motor via a drive shaft.

12. The dynamic aperture of claim 8, wherein the planar object further comprises a drive shaft located at a center of the disc, and wherein a belt couples the drive shaft to the motor.

13. The dynamic aperture of claim 8, wherein a transmission couples the planar object to the motor.

14. The dynamic aperture of claim 8, wherein the motor is a DC brushless motor.

15. The dynamic aperture of claim 8, wherein the motor is a limited angular torque motor.

16. The dynamic aperture of claim 8, wherein the semi-circular beveled portion is formed on a perimeter of the dynamic aperture, and wherein a radius describing the perimeter of the dynamic aperture varies with a length of the semi-circular beveled portion.

17. A display system for displaying images, the display system comprising:

an array of light modulators configured to create images comprised of pixels by setting each light modulator in the array of light modulators into a state needed to properly display the images;

a light source to illuminate the array of light modulators, wherein a light from the light source reflecting off the array of light modulators forms the images on an image plane; and

a dynamic aperture positioned in an optical path of the display system, wherein the dynamic aperture rotates to variably pass light produced by the light source located on a first side of the dynamic aperture to a second side of the dynamic aperture, the dynamic aperture configured to attenuate the light produced by the light source, the dynamic aperture comprising a planar object with a semi-circular beveled portion formed on the first side of the planar object.

18. The display system of claim 17, wherein the semi-circular beveled portion has a tapered cross-section, and wherein planar object comprises a slot cut along a spine of the semi-circular beveled portion of the planar object and through the planar object, the slot having an inner edge with an inner radius and an outer edge with an outer radius, wherein at least the inner radius or the outer radius changes along with a length of the slot.

19. The display system of claim 17, wherein the dynamic aperture is positioned between the light source and the array of light modulators.

20. The display system of claim 17, wherein the array of light modulators is an array of spatial light modulators.

21. The display system of claim 20, wherein the array of light modulators is a digital micromirror device.