Driving system for display device

• US 20050190610A1
• Filed: 02/25/2005
• Published: 09/01/2005
• Est. Priority Date: 02/26/2004
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Shiomi, Makoto, Furukawa, Tomoo, Shigeta, Mitsuhiro, Shiraishi, Tai
• Granted Patent: US 7,738,000 B2
• Time in Patent Office: Days
• US Class Current: 365/189.05
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• 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 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/2055 the pattern being varied in time
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A driving system of the present invention for use in a displaying device is provided with a pseudo bit-depth extension section. In the pseudo bit-depth extension section, a noise pattern is added to upper-n-bit data of an input signal D0 in m-bit, where (i) m is an integer of 9 or greater, and (ii) n is an integer of 8 or greater, but less than m. Then, upper-n-bit of data D1 thus obtained from the D0 is outputted, as output data D2, from the pseudo bit-depth extension section. The driving system is further provided with an overshoot-driving section for carrying out an overshoot-driving with respect to each of pixels. A noise amount of the noise pattern is 1 or less in 8-bit data, and a calculation in the overshoot-driving section is carried out with n-bit data. With this driving system which adopts a combination of (a) a overshoot-driving method for enforcing liquid crystal to respond at a high speed, and (b) a bit-depth extension technology in which a number of grayscales is increased by adding noise, it is possible to provide, at a low cost, a high-definition displaying device such as a liquid crystal display, having a high-response-characteristics and a high quality of grayscale reproduction.

Claims

1. A driving system, for use in a displaying device capable of gradation display, comprising:

a pseudo bit-depth extension block for increasing visible gradation levels by (i) adding a noise pattern to upper-8-bits of input m-bit data (m being an integer not less than

     9), and (ii) outputting as output data upper-n-bit (n being an integer not less than 8 and less than m) of data obtained by adding the noise pattern to the upper-8 bits of the input m-bit data;

an overshoot-driving block for performing overshoot-driving in display operation,

an amount of the noise pattern being not more than 1 in 8-bit data, and

the overshoot-driving block for performing calculation on 8-bit basis.

2. The driving system as set forth in claim 1, wherein:

the pseudo bit-depth extension block is positioned in a preceding stage of the overshoot-driving block; and

the overshoot-driving block performs the calculation using upper-8-bit of input n-bit data of the overshoot-driving block.

3. The driving system as set forth in claim 1, wherein:

the pseudo bit-depth extension block is positioned in a following stage of the overshoot-driving block; and

the overshoot-driving block carries out the calculation using upper-8-bit of input m-bit data to the overshoot-driving block.

4. The driving system as set forth in claim 1, further comprising:

an independent γ

-processing block provided in a preceding stage of the pseudo bit-depth extension block, for respectively converting R, G and B signals into m-bit data.

5. The driving system as set forth in claim 1, further comprising:

an independent γ

-processing block provided in a preceding stage of the overshoot-driving block, for respectively converting R, G and B signals into m-bit data.

6. The driving system as set forth in claim 4, wherein:

the independent γ

-processing block is supplied with a signal ranging from 6-bits to m-bits.

7. The driving system as set forth in claim 5, wherein:

the independent γ

-processing block is supplied with a signal ranging from 6-bits to m-bits.

8. The driving system as set forth in claim 4, further comprising:

a grayscale cutting block provided in a preceding stage of the independent γ

-processing block, for cutting off a part of grayscales of an input grayscale signal, or for compressing the grayscales to a region where a part of the grayscales is excluded.

9. The driving system as set forth in claim 4, further comprising:

a grayscale cutting block provided in a following stage of the independent γ

-processing block, for cutting or compressing at least one of upper and/or lower grayscales represented by a grayscale signal.

10. The driving system as set forth in claim 8, further comprising:

a look-up-table containing a combination of a conversion rule applied in the independent γ

-processing block and a conversion rule applied in the grayscale cutting block.

11. The driving system as set forth in claim 9, further comprising:

a look-up-table containing a combination of a conversion rule applied in the independent γ

-processing block and a conversion rule applied in the grayscale cutting block.

12. The driving system as set forth in claim 4, further comprising:

a look-up-table containing a conversion rule determined according to (i) conversion data used in the independent γ

-processing block and (ii) an overshooting parameter of the overshoot-driving block.

13. The driving system as set forth in claim 4, further comprising:

a look-up-table specifying conversion data for use in the independent γ

-processing block; and

a look-up-table specifying an overshooting parameter of the overshoot-driving block.

14. The driving system as set forth in claim 1, wherein the noise pattern is defined by a local coordination of a region whose sized is 4×

4×

RGB, 8×

8×

RGB, or 16×

16×

RGB.

15. The driving system as set forth in claim 1, wherein the noise pattern is defined by information contained in lower (m-n)-bit data of the m-bit data, and a frame counter.

16. The driving system as set forth in claim 1, wherein a block of the noise pattern has a time period of 8 frames or 16 frames.

17. The driving system as set forth in claim 1, wherein:

the overshoot-driving block outputs 8-bit data resulted from overshoot-driving that is performed by using a current frame data and a previous frame, the current frame data being 8-bit data processed in the pseudo bit-depth extension block, and the previous frame being data which has been stored in a frame memory.

18. The driving system as set forth in claim 8, wherein:

the overshoot-driving block outputs 8-bit data resulted from overshoot-driving that is performed by using a current frame data and a previous frame,

the current frame data being 8-bit data processed by (a) the grayscale cutting block, the independent γ

-processing block, and the pseudo bit-depth extension block in this order, or by (b) the independent γ

-processing block, the grayscale cutting block, and the pseudo bit-depth extension block in this order, and

the previous frame data being data which has been stored in a frame memory.

19. The driving system as set forth in claim 9, wherein:

the overshoot-driving block outputs 8-bit data resulted from overshoot-driving that is performed by using a current frame data and a previous frame,

the current frame data being 8-bit data processed by (a) the grayscale cutting block, the independent γ

-processing block, and the pseudo bit-depth extension block in this order, or by (b) the independent γ

-processing block, the grayscale cutting block, and the pseudo bit-depth extension block in this order, and

the previous frame data being data which has been stored in a frame memory.

28. The driving system as set forth in claim 1, wherein:

a default γ

-value of luminance property of the displaying device is not less than an output γ

-value whose value is estimated based on an input signal.

29. The driving system as set forth in claim 28, wherein the output γ

-value is between 2.5 and 3.0.

30. The driving system as set forth in claim 8, wherein:

a γ

-value is set high for grayscales between a highest grayscale and a grayscale corresponding to a maximum output of the grayscale cutting block; and

a γ

-value is set relatively low for other grayscales.

41. The driving system as set forth in claim 9, wherein:

a γ

-value is set high for grayscales between a highest grayscale and a grayscale corresponding to a maximum output of the grayscale cutting block; and

a γ

-value is set relatively low for other grayscales.

20. A driving system for use in a displaying device capable of gradation display with respect to each of pixels, wherein:

input data for producing grayscales is k-bit data, where k is an integer and 6≦

k<

m (where m is an integer not less than

     9);

when k≦

7, 0 is added to lower-(8-K) bit of the input k-bit data, and data obtained by adding 0 is stored in a frame memory;

when k≧

8, upper-8-bits of the k-bit data is stored in the frame memory;

the input k-bit-data is converted into m-bit-data in an independent γ

-processing block;

overshoot-driving is carried out based on current frame data and previous frame data wherein the current frame data is upper-8-bit data of the γ

-processing data, and the previous frame data is data stored in the frame memory;

lower-(m-8) bit data of the current frame data is added to data resulted from the overshoot-driving so that m-bit overshoot-driving data is created; and

the m-bit overshoot-driving data is processed in a pseudo bit-depth extension block, and is outputted in the form of 8-bit data.

26. The driving system as set forth in claim 20, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

27. The driving system as set forth in claim 20, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

21. A driving system for use in a displaying device capable of gradation display with respect to each of pixels, wherein:

input data for producing grayscales is k-bit data, where k is an integer and 6≦

k<

m (where m is an integer not less than

     9);

when k≦

7, 0 is added to lower-(8-K) bit of the input k-bit data, and data obtained by adding 0 is stored in a frame memory;

when k≧

8, upper-8-bits of the k-bit data is stored in the frame memory;

the input k-bit-data is converted into 8-bit data by an independent γ

-processing block and pseudo bit-depth extension block in this order;

overshoot-driving is carried out based on current frame data and previous frame data wherein the current frame data is the 8-bit-data obtained through the independent γ

-processing block and the pseudo bit-depth extension block, and the previous frame data is data stored in the frame memory;

data resulted from the overshoot driving is outputted in the form of 8-bit data.

31. The driving system as set forth in claim 21, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

36. The driving system as set forth in claim 21, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

22. A driving system for use in a displaying device capable of gradation display with respect to each of pixels, wherein:

input data for producing grayscales is k-bit data, where k is an integer and 6≦

k<

m (where m is an integer not less than

     9);

when k≧

7, 0 is added to lower-(8-K) bit of the input k-bit data, and data obtained by adding 0 is stored in a frame memory;

when k≧

8, upper-8-bits of the k-bit data is stored in the frame memory;

the input k-bit-data is converted into m-bit data by (i) a grayscale cutting block and an independent γ

-processing block in this order, or (ii) an independent γ

-processing block and a grayscale cutting block in this order;

overshoot-driving is carried out based on current frame data and previous frame data wherein the current frame data is upper-8-bit-data of the m-bit data, and the previous frame data is data stored in the frame memory;

lower-(m-8) bit data of the current frame data is added to data resulted from the overshoot-driving so that m-bit overshoot-driving data is created; and

the m-bit data obtained by adding the lower-(m-8) bit data is added is processed in a pseudo bit-depth extension block, and is outputted in the form of 8-bit data.

32. The driving system as set forth in claim 22, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

37. The driving system as set forth in claim 22, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

42. The driving system as set forth in claim 22, wherein:

a γ

-value is set high for grayscales between a highest grayscale and a grayscale corresponding to a maximum output of the grayscale cutting block; and

a γ

-value is set relatively low for other grayscales.

23. A driving system for use in a displaying device capable of gradation display with respect to each of pixels, wherein;

input data for producing grayscales is k-bit data, where k is an integer and 6≦

k<

m (where m is an integer not less than

     9);

when k≦

7, 0 is added to lower-(8-K) bit of the input k-bit data, and data obtained by adding 0 is stored in a frame memory;

when k≧

8, upper-8-bits of the k-bit data is stored in the frame memory;

the input k-bit-data is converted into m-bit-data in an independent γ

-processing block;

overshoot-driving is carried out based on current frame data and previous frame data wherein the current frame data is upper-8-bit data of the m-bit γ

-processing data, and the previous frame data is data stored in the frame memory;

lower-(m-8) bit data of the current frame data is added to data resulted from the overshoot-driving so that m-bit is created; and

the m-bit data to which the lower-(m-8) bit data is added is processed in a pseudo bit-depth extension block, and is outputted in the form of 8-bit data.

33. The driving system as set forth in claim 23, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

38. The driving system as set forth in claim 23, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

43. The driving system as set forth in claim 23, wherein:

a γ

-value is set high for grayscales between a highest grayscale and a grayscale corresponding to a maximum output of the grayscale cutting block; and

a γ

-value is set relatively low for other grayscales.

24. A driving system for use in a displaying device capable of gradation display with respect to each of pixels, wherein:

input data for producing grayscales is k-bit data, where k is an integer and 6≦

k <

m (where m is an integer not less than

     9);

when k≦

7, 0 is added to lower-(8-K) bit of the input k-bit data, and data obtained by adding 0 is stored in a frame memory;

when k≧

8, upper-8-bits of the k-bit data is stored in the frame memory;

the input k-bit data is converted into 8-bit data by (i) a grayscale cutting block, an independent γ

-processing block and a pseudo bit-depth extension block in this order, or (ii) the independent γ

-processing block, the grayscale cutting block, and the pseudo bit-depth extension block in this order;

overshoot-driving is carried out based on current frame data and previous frame data wherein the current frame data is the 8-bit-data converted from the input k-bit data, and the previous frame data is data stored in the frame memory;

data resulted from the overshoot driving is outputted in the form of 8-bit data.

34. The driving system as set forth in claim 24, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

39. The driving system as set forth in claim 24, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

25. A driving system for use in a displaying device capable of gradation display with respect to each of pixels, wherein:

input data for producing grayscales is k-bit data, where k is an integer and 6≦

k<

m (where m is an integer not less than

     9);

when k≦

7, 0 is added to lower-(8-K) bit of the input k-bit data, and data obtained by adding 0 is stored in a frame memory;

when k≧

8, upper-8-bits of the k-bit data is stored in the frame memory;

overshoot-driving is carried out based on current frame data and previous frame data wherein the current frame data is the 8-bit-data obtained through the independent γ

-processing block and the pseudo bit-depth extension block, and the previous frame data is data stored in the frame memory;

data resulted from the overshoot driving is outputted in the form of 8-bit data.

35. The driving system as set forth in claim 25, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.

40. The driving system as set forth in claim 25, wherein:

a part of look-up-tables for use in processes by the blocks, sequentially arranged without interposing a memory, is used as a common look up table for all of the blocks, so that the blocks form one conversion block.