Generating load/reset sequences for spatial light modulator

• US 6,008,785 A
• Filed: 11/20/1997
• Issued: 12/28/1999
• Est. Priority Date: 11/28/1996
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Hewlett, Gregory J., Doherty, Donald B.
• Primary Examiner(s): Powell, Mark R.
• Assistant Examiner(s): Kovalick, Vincent E.
• Application Number:
  US08/975,377
• Time in Patent Office: 768 Days
• Field of Search: 345/48, 345/84, 345/85, 345/108, 345/148, 345/204, 348/755, 348/770, 349/24, 349/25
• US Class Current: 345/85
• CPC Class Codes: G09G 2310/0205 Simultaneous scanning of several lines in flat panels
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2033 with splitting one or more sub-frames corresponding to the most significant bits into two or more sub-frames
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833

Abstract

A method of automatically generating a load/reset sequence for a display system having a spatial light modulator whose display elements that are loaded with data and reset between loads (FIG. 7). Bit-planes of data are classified according to their display times as normal, short, or reset-release (FIG. 5). Extra time of normal bit-planes is calculated (FIG. 5). The display times of normal bit-planes are adjusted by subtracting or adding extra time, such that any normal bit-plane displayed before a short or reset-release bit-plane includes sufficient extra time to allow for loading the short or reset-release bit-plane (FIG. 7). Also, reset conflicts are detected and avoided (FIGS. 7, 8, 9A and 9B).

Claims

1. A method for automatically providing a load/reset sequence for a divided reset display system having a divided reset spatial light modulator, whose display elements are addressed with data by means of loads and resets, said data being formatted in bit-planes, each bit-plane to be loaded as one or more segments during a frame time, and said spatial light modulator having a minimum load time, comprising the steps of:

storing a display order of said segments;

classifying each of said segments as having a normal display time or a short display time, said normal display time being at least as long as said minimum load time, and said short display time being less than said minimum load time;

subtracting said minimum load time from each said normal display time, thereby determining extra time for each said normal display time;

assigning an actual display time to each of said segments, such that each normal display time is given only said minimum load time;

adding at least part of said extra time to any said normal display time occurring before one of said short display times;

distributing any remaining extra time; and

setting a start time for each said load and reset of each of said segments.

2. The method of claim 1, further comprising the step of classifying at least one of said segments as having a reset-release display time.

3. The method of claim 2, wherein said setting step further comprises setting a start time for one or more reset release signals.

4. The method of claim 2, further comprising the step of placing one of said segments having a reset-release display time at the end of said frame time.

5. The method of claim 1, further comprising the step of globally resetting said display elements to begin said display time of at least one of said segments.

6. The method of claim 1, further comprising the step of calculating a used frame time representing the total display time and comparing said used frame time with a desired frame time.

7. The method of claim 1, wherein said adding step is performed by adding an amount of extra time sufficient to compensate the difference between said short display time and said minimum display time.

8. The method of claim 1, wherein said display elements have a hold time and a load time and wherein said short display time is at least as long as said reset time plus said hold time.

9. A method for automatically providing a load/reset sequence for a display system having a global reset spatial light modulator, whose display elements are addressed with data by means of loads and resets, said data being formatted in bit-planes, each bit-plane to be loaded as one or more segments during a frame time, and said spatial light modulator having a minimum load time, comprising the steps of:

storing a display order of said segments;

classifying each of said segments as having a normal display time or a short display time, said normal display time being at least as long as said minimum load time, and said short display time being less than said minimum load time;

dividing said frame time into said display times;

placing a clear after each said segment having a short display time; and

setting a start time for each said load, reset, and clear of each of said segments.

10. The method of claim 9, further comprising the step of classifying at least one of said segments as having reset-release display time.

11. The method of claim 10, wherein said setting step further comprises setting a start time for one or more reset release signals.

12. The method of claim 9, further comprising the step of calculating a used frame time representing the total display time and comparing said used frame time with a desired frame time.

13. The method of claim 12, wherein said short display times are at least as long as said hold time plus time for said clear.

14. The method of claim 9, wherein said display elements have a hold time and wherein said normal display time is at least as long as said hold time plus said minimum load time.

15. A method for automatically providing a load/reset sequence for a display system having a divided reset spatial light modulator, whose display elements are addressed with data by means of loads and resets, said data being formatted in bit-planes, each bit-plane to be loaded as one or more segments during a frame time, and said spatial light modulator having a minimum load time, comprising the steps of:

storing a display order of said segments;

determining whether resetting of any said segment results in a reset conflict with the resetting of a next said segment, thereby identifying a conflicting segment;

determining whether said conflicting segment is of a bit-plane having multiple segments; and

if said conflicting segment is of a bit-plane having multiple segments, avoiding said reset conflict by adjusting said display time of said conflicting segment and counter adjusting another segment of the associated bit-plane; and

setting start times for each load and reset of each said segment.

16. The method of claim 15, further comprising the step of avoiding said reset conflict by adjusting the reset skews of said conflicting segment and of said next said segment, if said conflicting segment is not of a bit-plane having multiple segments.

17. The method of claim 15, further comprising the step of determining whether said conflicting segment is bordered by segments of the same bit-plane and, if not, counter adjusting reset skews elsewhere during said frame time.

18. The method of claim 15, wherein said conflicting segment has a reset-release display time, such that said segment is terminated with a reset release signal, and wherein said step of avoiding said reset conflict is accomplished by adjusting the hold time of said conflicting segment.