Display device, driving method of the display device, and electronic device

• US 20060232600A1
• Filed: 04/04/2006
• Published: 10/19/2006
• Est. Priority Date: 04/14/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime, Shishido, Hideaki
• Granted Patent: US 8,633,919 B2
• Time in Patent Office: Days
• US Class Current: 345/605
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2320/0266 Reduction of sub-frame artefacts
• 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 3/204 the sub-frames being organized in consecutive sub-frame groups
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]

Abstract

To reduce a pseudo contour which occurs when displaying by a time gray scale method. When gradation is expressed with an n bit, the bits are divided into three bit groups, and one frame is divided into two subframe groups. Then, a (0<a<n) subframes corresponding to bits belonging to a first bit group are divided into three or more, each about half of which is arranged in each subframe group; b (0<b<n) subframes corresponding to bits belonging to a second bit group are divided into two, each one of which is arranged in each the subframe group; and c (0≦c<n and a+b+c=n) subframes corresponding to bits belonging to a third bit group are arranged in at least one of the subframe groups.

Claims

1. A driving method of a display device for expressing gradation by dividing one frame into a plurality of subframes, in the case where gradation is expressed with an n bit (here n is an integral number), comprising:

classifying bits each of which is shown by a binary of gray scales into three kinds of bit groups, that is, a first bit group, a second bit group, and a third bit group;

dividing the one frame into two subframe groups;

dividing each of a (here, a is an integral number satisfying 0<

a<

n) subframes corresponding to bits belonging to the first bit group into three or more, and arranging each about half of which in each of the two subframe groups of the one frame;

dividing each of b (here, b is an integral number satisfying 0<

b<

n) subframes corresponding to bits belonging to the second bit group into two, and arranging each one of which in each of the two subframe groups of the one frame; and

arranging c (here, c is an integral number satisfying 0≦

c<

n and a+b+c=n) subframes corresponding to bits belonging to the third bit group in at least one of the two subframe groups of the one frame,

wherein an appearance order of a plurality of subframes corresponding to bits belonging to the first bit group and a plurality of subframes corresponding to bits belonging to the second bit group is approximately the same between the two subframe groups of the one frame.

2. The driving method of a display device according to claim 1, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the first bit group light and then, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light.

3. The driving method of a display device according to claim 1, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light and then, all the subframes corresponding to the bits belonging to the first bit group light.

4. The driving method of a display device according to claim 1, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the first bit group lights, and at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, another one of the plurality of subframes corresponding to the bits belonging to the first bit group lights.

5. The driving method of a display device according to claim 1, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, and at least one of a plurality of subframes corresponding to higher-order bits lights, another one of the plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights.

6. A display device using the driving method according to claim 1.

7. An electronic device using the driving method according to claim 6.

8. A driving method of a display device for expressing gradation by dividing one frame into a plurality of subframes, in the case where gradation is expressed with an n bit (here n is an integral number), comprising:

classifying bits each of which is shown by a binary of gray scales into three kinds of bit groups, that is, a first bit group, a second bit group, and a third bit group;

dividing the one frame into k (here k is an integral number satisfying k=3) subframe groups;

dividing each of a (here, a is an integral number satisfying 0<

a<

n) subframes corresponding to bits belonging to the first bit group into (k+1) or more, and arranging each about half of which in each of the k subframe groups of the one frame;

dividing each of b (here, b is an integral number satisfying 0<

b<

n) subframes corresponding to bits belonging to the second bit group into k, and arranging each one of which in each of the k subframe groups of the one frame; and

dividing each of c (here c is an integral number satisfying 0≦

c<

n and a+b+c=n) subframes corresponding to bits belonging to the third bit group into in (k−

1) or less or not dividing, and arranging in at least one of the k subframe groups of the one frame,

wherein an appearance order of a plurality of subframes corresponding to bits belonging to the first bit group and a plurality of subframes corresponding to bits belonging to the second bit group is approximately the same among the k subframe groups of the one frame.

9. The driving method of a display device according to claim 8, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the first bit group light and then, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light.

10. The driving method of a display device according to claim 8, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light and then, all the subframes corresponding to the bits belonging to the first bit group light.

11. The driving method of a display device according to claim 8, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the first bit group lights, and at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, another one of the plurality of subframes corresponding to the bits belonging to the first bit group lights.

12. The driving method of a display device according to claims 8, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, and at least one of a plurality of subframes corresponding to higher-order bits lights, another one of the plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights.

13. A display device using the driving method according to claim 8.

14. An electronic device using the driving method according to claim 13.

15. A driving method of a display device for expressing gradation by dividing one frame into a plurality of subframes, in the case where gradation is expressed with an n bit (here n is an integral number), comprising:

classifying bits each of which is shown by a binary of gray scales into three kinds of bit groups, that is, a first bit group, a second bit group, and a third bit group;

dividing the one frame into two subframe groups;

dividing each of a (here, a is an integral number satisfying 0<

a<

n) subframes corresponding to bits belonging to the first bit group into three or more, and arranging each about half of which in each of the two subframe groups of the one frame;

dividing each of b (here, b is an integral number satisfying 0<

b<

n) subframes corresponding to bits belonging to the second bit group into two, and arranging each one of which in each of the two subframe groups of the one frame; and

arranging c (here, c is an integral number satisfying 0≦

c<

n and a+b+c=n) subframes corresponding to bits belonging to the third bit group in at least one of the two subframe groups of the one frame,

wherein an appearance order of a plurality of subframes corresponding to bits belonging to the first bit group and a plurality of subframes corresponding to bits belonging to the second bit group is approximately the same between the two subframe groups of the one frame,

wherein luminance is changed linearly in a region of a low gray scale level and in the other region of the other gray scale levels, luminance is changed nonlinearly.

16. The driving method of a display device according to claim 15, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the first bit group light and then, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light.

17. The driving method of a display device according to claim 15, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light and then, all the subframes corresponding to the bits belonging to the first bit group light.

18. The driving method of a display device according to claim 15, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the first bit group lights, and at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, another one of the plurality of subframes corresponding to the bits belonging to the first bit group lights.

19. The driving method of a display device according to claim 15, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, and at least one of a plurality of subframes corresponding to higher-order bits lights, another one of the plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights.

20. A display device using the driving method according to claim 15.

21. An electronic device using the driving method according to claim 20.

22. A driving method of a display device for expressing gradation by dividing one frame into a plurality of subframes, in the case where gradation is expressed with an n bit (here n is an integral number), comprising:

classifying bits each of which is shown by a binary of gray scales into three kinds of bit groups, that is, a first bit group, a second bit group, and a third bit group;

dividing the one frame into k (here k is an integral number satisfying k=3) subframe groups;

dividing each of a (here, a is an integral number satisfying 0<

a<

n) subframes corresponding to bits belonging to the first bit group into (k+1) or more, and arranging each about half of which in each of the k subframe groups of the one frame;

dividing each of b (here, b is an integral number satisfying 0<

b<

n) subframes corresponding to bits belonging to the second bit group into k, and arranging each one of which in each of the k subframe groups of the one frame; and

dividing each of c (here c is an integral number satisfying 0≦

c<

n and a+b+c=n) subframes corresponding to bits belonging to the third bit group into in (k−

1) or less or not dividing, and arranging in at least one of the k subframe groups of the one frame,

wherein an appearance order of a plurality of subframes corresponding to bits belonging to the first bit group and a plurality of subframes corresponding to bits belonging to the second bit group is approximately the same among the k subframe groups of the one frame,

wherein luminance is changed linearly in a region of a low gray scale level and in the other region of the other gray scale levels, luminance is changed nonlinearly.

23. The driving method of a display device according to claim 22, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the first bit group light and then, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light.

24. The driving method of a display device according to claim 22, wherein in at least one of the plurality of subframe groups of the one frame, all the subframes corresponding to the bits belonging to the second bit group or the third bit group light and then, all the subframes corresponding to the bits belonging to the first bit group light.

25. The driving method of a display device according to claim 22, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the first bit group lights, and at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, another one of the plurality of subframes corresponding to the bits belonging to the first bit group lights.

26. The driving method of a display device according to claim 22, wherein in at least one of the plurality of subframe groups of the one frame, after at least one of a plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights, and at least one of a plurality of subframes corresponding to higher-order bits lights, another one of the plurality of subframes corresponding to the bits belonging to the second bit group or the third bit group lights.

27. A display device using the driving method according to claim 22.

28. An electronic device using the driving method according to claim 27.