IP Library Granted Patent US 6,856,447
Granted Patent B2
US 6,856,447 · App. 10/407,061 · Granted Feb 15, 2005

Methods and apparatus for selectively updating memory cell arrays

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Quick Facts
Patent No.
US 6,856,447
App. No.
10/407,061
Granted
Feb 15, 2005
Kind
B2
Abstract

Methods and apparatus for selectively updating memory cells of a memory cell array are provided. The memory cells of each row of the memory cell array are provided with a plurality of wordlines. Memory cells of the row are activated and updated by separated wordlines. In an application of display systems using memory cell arrays for controlling the pixels of the display system and pulse-width-modulation (PWM) technique for displaying grayscales, the pixels can be modulated by different PWM waveforms. The perceived dynamic-false-contouring artifacts are reduced thereby. In another application, the provision of multiple wordlines enables precise measurements of voltages maintained by memory cells of the memory cell array.

Claims (20)

1. A projector, comprising:

a light source;

a spatial light modulator, comprising:

an array of micromirrors; and

a plurality of wordlines, wherein each wordline is connected to every other

micromirror in a row of the micromirror array;

a set of optical elements; and

a display target.

2. The projector of claim 1 , wherein adjacent micromirrors in a row of the array are connected to separate wordlines of the plurality of wordlines for the row.

3. The projector of claim 2 , wherein at least two wordlines are connected to the micromirrors of a row of the micromirror array, wherein each wordline is connected to every other micromirror of the row of the micromirror array; and the wordlines are connected to different micromirrors.

4. The projector of claim 1 , wherein four wordlines are connected to micromirrors of a 2×3 micromirror sub-array of the micromirror away.

5. The projector of claim 1 , wherein each micromirror of the micromirror array is associated with a memory cell connected to an electrode, and wherein each micromirror comprises a deflectable reflective mirror plate that is coupled to the electrode end memory cell.

6. The projector of claim 5 , wherein the memory cell is a charge-pump memory cell.

7. The projector of claim 5 , wherein the memory cell is a DRAM.

8. The projector of claim 5 , wherein the micromirror and the memory cell are formed on a semiconductor substrate.

9. The projector of claim 5 , wherein the micromirror and the memory cell are formed on separate substrates.

10. The projector of claim 9 , wherein the micromirror is formed on a tight transmissive substrate.

11. The projector of claim 9 , wherein the memory cell comprises a transistor and a capacitor farmed on a semiconductor substrate.

12. The projector of claim 1 , further comprising: a color wheel.

13. The projector of claim 1 , further comprising: a light pipe.

Assignments (3)
RELEASE OF SECURITY INTEREST Recorded Jul 11, 2006
From: VENTURE LENDING & LEASING IV, INC.
To: REFLECTIVITY, INC.
Reel/Frame 017906/0887 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 10, 2006
From: REFLECTIVITY, INC.
To: TEXAS INSTRUMENTS INCORPORATED
Reel/Frame 017897/0553 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 28, 2005
From: REFLECTIVITY, INC.
To: VENTURE LENDING & LEASING IV, INC.
Reel/Frame 016800/0574 →