Time sequential lookup table arrangement for a display

• US 6,373,497 B1
• Filed: 05/14/1999
• Issued: 04/16/2002
• Est. Priority Date: 05/14/1999
• Status: Expired due to Term

• Current Assignee: Emerson Radio Corporation (Nimble Holdings Co. Ltd.)
• Original Assignee: Zight Corporation (Three-Five Systems, Inc.)
• Inventors: McKnight, Douglas J., Gorny, Douglas J., Bohn, Jr., Lowell F.
• Primary Examiner(s): Chauhan, Ulka J.
• Application Number:
  US09/312,196
• Time in Patent Office: 1,068 Days
• Field of Search: 345/519, 345/199, 345/155, 345/153, 345/204-206, 345/88, 345/600, 345/601, 345/602, 345/605, 345/536
• US Class Current: 345/602
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2330/04 Display protection
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables

Abstract

A method and apparatus employing lookup tables in a time sequential manner. A substrate has a display, a digital to analog converter, and a lookup table (LUT) formed thereon. The LUT is loaded with a LUT data set corresponding to an image subframe to be driven to the display. Successive LUT data sets corresponding to the next subframe are loaded after each subframe is driven to the display.

Claims

1. An apparatus comprising:

a display formed on a first substrate;

a digital to analog converter (DAC) coupled to the display and formed on the first substrate with the display; and

a lookup table (LUT) coupled to the DAC and formed on the first substrate.

2. The apparatus of claim 1 further comprising:

a storage device on a second substrate, the storage device storing a plurality of LUT data sets; and

a state machine to select which LUT data set of the plurality of LUT data sets to load into the LUT.

3. The apparatus of claim 2 wherein the state machine cycles through a sequence of LUT data sets selected from the group of R, G, B, {overscore (R)}, {overscore (G)}, {overscore (B)}.

4. The apparatus of claim 3 wherein the sequence includes the pattern R, {overscore (G)}, B, {overscore (R)}, G, {overscore (B)}.

5. The apparatus of claim 3 where the sequence alternates between a data set for a color and a data set for an inverted color.

6. The apparatus of claim 2 further comprising:

a parser that segregates incoming image data into monochrome subframes; and

a memory controller that stores the subframes in the storage device.

7. The apparatus of claim 2 wherein the LUT data sets map an m-bit value into an n-bit value where n>

m.

8. The apparatus of claim 2 wherein the LUT data sets adjust for non-linearity in the DAC and the liquid crystal.

9. The apparatus of claim 2 wherein the plurality of LUT data sets includes a data set corresponding to at least one of a temperature range, and a contrast control.

10. The apparatus of claim 2 wherein the state machine cycles through R, G, B LUT data sets and performs digital inversion of every second data set.

11. The apparatus of claim 1 wherein the display has a data path, the data path having a width of r pixels wherein one LUT and one DAC are formed on the substrate for each of the r pixels of the data path wherein r is a positive integer.

12. A method comprising:

retaining a plurality of lookup table (LUT) data sets in a storage device;

loading a first LUT data set of the plurality into a LUT;

receiving a first plurality of signals at the LUT corresponding to a subframe of an image to be displayed;

loading a next LUT data set of the plurality into the LUT; and

receiving a second plurality of signals corresponding to a next subframe of an image to be displayed.

13. The method of claim 12 wherein there are three LUT data sets in the plurality and wherein one of the LUT data sets corresponds to each of R, G, and B, and wherein said LUT is disposed on a semiconductor substrate and wherein the semiconductor substrate comprises display logic which forms an image on the semiconductor substrate.

14. The method of claim 13 wherein the LUT is loaded in a repetitive sequence having R, {overscore (G)}, B, {overscore (R)}, G, {overscore (B)} as a segment thereof.

15. The method of claim 12 wherein the storage device is formed on a different substrate from the LUT.

16. The method of claim 12 further comprising:

encoding the first plurality of signals based on the LUT data set currently in the LUT;

driving the display based on the encoding; and

illuminating the display with a corresponding light color.

17. The method of claim 12 further comprising:

repeatedly displaying subframes of a first frame until a second frame is available for display.

18. The method of claim 12 wherein the first plurality of signals is retained in a buffer, further comprising:

reloading the buffer with a next plurality of signals corresponding to a portion of the next frame during a non-displaying time of the first plurality of signals.

19. A system comprising:

a display formed on a first substrate;

a lookup table (LUT) coupled to the display and formed on the first substrate;

an image data source;

a storage unit to store a plurality of subframes of an image frame;

a plurality of LUT data sets corresponding to subframes, the LUT data sets stored external to the first substrate; and

a state machine that sequentially loads the LUT data sets into the lookup table on the first substrate.

20. The system of claim 19 wherein the storage unit and the state machine are formed on a second substrate.

21. The system of claim 20 wherein the LUT data sets are stored on the second substrate prior to loading into the LUT.

22. The system of claim 19 wherein the subframes include a red (R) subframe, a green (G) subframe, and a blue (B) subframe.

23. The system of claim 19 wherein a sequence in which the LUT is loaded alternates between a subframe data set and an inverted subframe data set.

24. The system of claim 19 wherein the plurality of LUT data sets comprise sets corresponding to inverted subframes.