Display device and driving method for display device

• US 8,913,212 B2
• Filed: 10/04/2011
• Issued: 12/16/2014
• Est. Priority Date: 10/14/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Wakimoto, Kenichi
• Primary Examiner(s): Caley, Michael
• Assistant Examiner(s): PAN, JIA X
• Application Number:
  US13/252,228
• Publication Number:
  US 20120092587A1
• Time in Patent Office: 1,169 Days
• Field of Search: 349 61- 69, 362/97.3, 362/600, 362/615, 362/612, 345/84, 345/87, 345/102
• US Class Current: 349/62
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

An object is to suppress degradation of an image quality of a display image. A plurality of display circuits arranged in M rows (M is a natural number of 2 or more) and N columns (N is a natural number) and a light unit are included; the light unit includes a plurality of light-emitting diode groups arranged in X rows (X is a natural number of 2 or more), overlaps with a display circuit in at least different one or more rows every row, and includes a light-emitting diode emitting red light, a light-emitting diode emitting green light and a light-emitting diode emitting blue light and a light guide plate formed between the plurality of display circuits and the plurality of light-emitting diode groups. The light guide plate includes X light guide members which transmits the light of the light-emitting diode groups in the rows different from each other.

Claims

1. A display device comprising:

a plurality of display circuits arranged in M rows (M is a natural number of 2 or more) and N columns (N is a natural number), wherein the M rows include a first group of consecutive rows of the M rows, and a second group of consecutive rows of the M rows, and wherein the first group does not overlap with the second group; and

a light unit overlapping with the plurality of display circuits, the light unit comprising;

a plurality of light-emitting diode groups arranged in X rows (X is a natural number of 2 or more), wherein the plurality of light-emitting diode groups arranged in one of the X rows overlaps with one row of the first group of the plurality of display circuits, the plurality of light-emitting diode groups arranged in another one of the X rows overlaps with one row of the second group of the plurality of display circuits, and each of the light-emitting diode groups includes a light-emitting diode emitting red light, a light-emitting diode emitting green light, and a light-emitting diode emitting blue light; and

a light guide plate formed between the plurality of display circuits and the plurality of light-emitting diode groups and in contact with the plurality of light-emitting diode groups, the light guide plate comprising X light guide members arranged in a column direction of the light-emitting diode groups so that each member corresponds to one of the rows of light-emitting diodes,

the display device being configured so that

the one row of the first group of the plurality of display circuits is in a writing state to be input with first display data signals corresponding to a first color or combination of colors at the same time as the one row of the second group of the plurality of display circuits is in the writing state to be input with second display data signals corresponding to a second color or combination of colors different from the first color or combination of colors, and

during the writing state, the light-emitting diodes arranged in the one row of the X rows and the light-emitting diodes arranged in the another row of the X rows are in an off state,

wherein each of the X light guide members overlaps a corresponding one of the X rows of light-emitting diodes,

wherein side surfaces of the X light guide members have light-reflective properties, and

wherein top and bottom surfaces of the X light guide members have light-transmitting properties.

2. The display device according to claim 1,

wherein the plurality of light-emitting diode groups is arranged in a grid pattern.

3. The display device according to claim 1,

wherein the plurality of light-emitting diode groups is arranged in a staggered pattern.

4. The display device according to claim 1,

wherein each of the plurality of display circuits includes a display selection transistor and a liquid crystal element.

5. The display device according to claim 1, further comprising a diffusion sheet overlapping with the plurality of light-emitting diode groups with the light guide plate interposed therebetween,

wherein the diffusion sheet is a sheet by which light is diffused in a circular pattern or an elliptic pattern.

6. The display device according to claim 1, further comprising a diffusion sheet overlapping with the plurality of light-emitting diode groups with the light guide plate interposed therebetween,

wherein a distance between the light guide plate and the diffusion sheet is 5 mm or smaller.

7. The display device according to claim 1,

wherein a light-reflecting film with a thickness of 0.2 μ

m or larger is formed on each of the side surfaces of the X light guide members.

8. A display device comprising:

a plurality of display circuits arranged in M rows (M is a natural number of 2 or more) and N columns (N is a natural number), wherein the M rows include a first group of consecutive rows of the M rows, and a second group of consecutive rows of the M rows, and wherein the first group does not overlap the second group; and

a light unit overlapping with the plurality of display circuits, the light unit comprising;

a plurality of light-emitting diode groups arranged in X rows (X is a natural number of 2 or more), wherein the plurality of light-emitting diode groups arranged in one of the X rows overlaps with one row of the first group of the plurality of display circuits, the plurality of light-emitting diode groups arranged in another one of the X rows overlaps with one row of the second group of the plurality of display circuits, and each of the light-emitting diode groups includes a light-emitting diode emitting red light, a light-emitting diode emitting green light, and a light-emitting diode emitting blue light; and

a light guide plate formed between the plurality of display circuits and the plurality of light-emitting diode groups and in contact with the plurality of light-emitting diode groups, the light guide plate comprising X light guide members overlapping with light-emitting diodes in successive plural rows out of the plurality of light-emitting diode groups; and

the display device being configured so that

the one row of the first group of the plurality of display circuits is in a writing state to be input with first display data signals corresponding to a first color or combination of colors at the same time as the one row of the second group of the plurality of display circuits is in the writing state to be input with second display data signals corresponding to a second color or combination of colors different from the first color or combination of colors, and

during the writing state, the light-emitting diodes arranged in the one row of the X rows and the light-emitting diodes arranged in the another row of the X rows are in an off state,

wherein each of the X light guide members overlaps a corresponding one of the X rows of light-emitting diodes,

wherein side surfaces of the X light guide members have light-reflective properties, and

wherein top and bottom surfaces of the X light guide members have light-transmitting properties.

9. The display device according to claim 8,

wherein the plurality of light-emitting diode groups is arranged in a grid pattern.

10. The display device according to claim 8,

wherein the plurality of light-emitting diode groups is arranged in a staggered pattern.

11. The display device according to claim 8,

wherein each of the plurality of display circuits includes a display selection transistor and a liquid crystal element.

12. The display device according to claim 8, further comprising a diffusion sheet overlapping with the plurality of light-emitting diode groups with the light guide plate interposed therebetween,

wherein the diffusion sheet is a sheet by which light is diffused in a circular pattern or an elliptic pattern.

13. The display device according to claim 8, further comprising a diffusion sheet overlapping with the plurality of light-emitting diode groups with the light guide plate interposed therebetween,

wherein a distance between the light guide plate and the diffusion sheet is 5 mm or smaller.

14. The display device according to claim 8,

wherein a light-reflecting film with a thickness of 0.2 μ

m or larger is formed on each of the side surfaces of the X light guide members.

15. A display device comprising:

a plurality of display circuits arranged in M rows (M is a natural number of 2 or more) and N columns (N is a natural number), wherein the M rows include a first group of consecutive rows of the M rows, and a second group of consecutive rows of the M rows, and wherein the first group does not overlap the second group; and

a light unit overlapping with the plurality of display circuits, the light unit comprising;

a plurality of light-emitting diode groups arranged in X rows (X is a natural number of 2 or more), wherein the plurality of light-emitting diode groups arranged in one of the X rows overlaps with one row of the first group of the plurality of display circuits, the plurality of light-emitting diode groups arranged in another one of the X rows overlaps with one row of the second group of the plurality of display circuits, and each of the light-emitting diode groups includes a light-emitting diode emitting red light, a light-emitting diode emitting green light, and a light-emitting diode emitting blue light; and

a light guide plate formed between the plurality of display circuits and the plurality of light-emitting diode groups and in contact with the plurality of light-emitting diode groups, the light guide plate comprising X light guide members arranged in a column direction of the light-emitting diode groups so that each member corresponds to one of the X rows of light-emitting diodes,

the display device being configured so that

the one row of the first group of the plurality of display circuits is in a writing state to be input with first display data signals corresponding to a first color or combination of colors at the same time as the one row of the second group of the plurality of display circuits is in the writing state to be input with second display data signals corresponding to a second color or combination of colors different from the first color or combination of colors,

during the writing state, the light-emitting diodes arranged in the one row of the X rows and the light-emitting diodes arranged in the another row of the X rows are in an off state, and

during the writing state, the light-emitting diodes arranged in a third one of the X rows emit light,

wherein each of the X light guide members overlaps a corresponding one of the X rows of light-emitting diodes,

wherein side surfaces of the X light guide members have light-reflective properties, and

wherein top and bottom surfaces of the X light guide members have light-transmitting properties.

16. The display device according to claim 15,

wherein the plurality of light-emitting diode groups is arranged in a grid pattern.

17. The display device according to claim 15,

wherein the plurality of light-emitting diode groups is arranged in a staggered pattern.

18. The display device according to claim 15,

wherein each of the plurality of display circuits includes a display selection transistor and a liquid crystal element.