Recursive feedback control of light modulating elements

• US 7,667,678 B2
• Filed: 05/10/2006
• Issued: 02/23/2010
• Est. Priority Date: 05/20/2003
• Status: Active Grant

• Current Assignee: Syndiant Incorporated
• Original Assignee: Syndiant Incorporated
• Inventors: Guttag, Karl M.
• Primary Examiner(s): Dharia; Prabodh M
• Application Number:
  US11/382,547
• Publication Number:
  US 20070132679A1
• Time in Patent Office: 1,385 Days
• Field of Search: 345/57, 345 84-100, 345/691, 345/530, 345/547, 382/274, 382/275, 324/536, 706/13, 700/1, 700/45, 700/42, 342/161, 342/89, 708/276, 708/300, 708/290, 708/306, 708/91, 708/307, 348/619, 386/21, 703/23
• US Class Current: 345/87
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 2310/0221 with use of split matrices G09G3/3644 and G09G3/3666 take precedence
• CPC Class Codes: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

In one embodiment, the present invention, one or more light modulating elements are controlled by a method comprising the following steps: controlling at least one pulse width using recursive feedback; and driving an electrode means using the pulse width to thereby control a light modulating element of an array of light modulating elements. In other embodiments, the present invention provides a method and system for determining a pulse wave form for each line of a two-dimensional array of drive bits using a recursive feedback process, wherein each drive bit in the array of drive bits is in an initialized state; and for turning all of the drive bits to an off state to thereby produce a blanking interval between fields for an image, wherein control of each of the pulse wave forms is staggered in time.

Claims

1. A method comprising the following steps:

(a) controlling at least one pulse width using recursive feedback; and

(b) driving an electrode using said pulse width to thereby control a light modulating element of an array of light modulating elements, wherein step (a) comprises a series of stages each having a stage value, wherein a plurality of bit locations are associated with a pixel value of said light modulating element, wherein at any given stage of said series of stages a subset of said bit locations are required to determine a next state of said light modulating element, and wherein said subset is determined based on said stage value.

2. The method of claim 1, wherein at a given stage only zeros in said stage value are required to determine said subset of said bit locations.

3. The method of claim 1, wherein at a given stage only ones in said stage value are required to determine said subset of said bit locations.

4. The method of claim 1, wherein said method further comprises the following step:

(c) logically combining said subset of said bit locations to form a logical combination, wherein said recursive feedback comprises combining said logical combination with a current output bit to determine a next output bit, and wherein in step (b) said next output bit is used to drive said electrode.

5. The method of claim 4, wherein said recursive feedback is explicit.

6. The method of claim 4, wherein said recursive feedback is implicit.

7. The method of claim 4, wherein at least some bit locations of said subset of said bit locations are held on a single substrate.

8. The method of claim 7, wherein all of said bit locations of said subset of bit locations are held on said single substrate.

9. The method of claim 7, wherein said substrate comprises a semiconductor material.

10. The method of claim 9, wherein said substrate comprises silicon.

11. The method of claim 1, wherein said next state of said modulating output is based on a sticky logical OR or a sticky logical AND of said subset of said bit locations.

12. The method of claim 1, wherein said light modulating elements are part of a visual display apparatus.

13. The method of claim 1, wherein said method is implemented in a computer system.

14. A method comprising:

determining a pulse wave form for each line of a two-dimensional array of drive bits using a recursive feedback process, wherein each drive bit in said array of drive bits is in an initialized state; and

turning all of said drive bits to an off state to thereby produce a blanking interval between fields for an image, wherein control of each of said pulse wave forms is staggered in time.

15. A system comprising:

means for determining a pulse wave form for each line of a two-dimensional array of drive bits using a recursive feedback process, wherein each drive bit in said array of drive bits is in an initialized state; and

means for turning all of said drive bits to an off state to thereby produce a blanking interval between fields for an image, wherein control of each of said pulse wave forms is staggered in time.