Display device

• US 6,563,482 B1
• Filed: 07/19/2000
• Issued: 05/13/2003
• Est. Priority Date: 07/21/1999
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei, Yamagata, Hirokazu
• Primary Examiner(s): Liang, Regina
• Application Number:
  US09/619,731
• Time in Patent Office: 1,028 Days
• Field of Search: 345/84, 345/87-89, 345/94, 345/96-99, 345/204, 345/209, 345/210, 345/92, 348/790, 349/42, 349/43, 349/46, 349/47
• US Class Current: 345/87
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 2320/0219 Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 29/78672 Polycrystalline or microcrystalline silicon transistor

Abstract

Display bright in contrast can be obtained without discrination and flicker in the display device of the direct vision type whose pixel pitches are short to 20 μm or less. A liquid crystal panel is driven through the frame inverse driving method, and the vertical frame frequency is set to 120 Hz or more. Also, each of the pixels is arranged to correspond to one of R, G and B of color filters disposed on a TFT substrate side.

Claims

1. A display device, comprising:

at least one driver circuit comprising a plurality of driver TFTs formed over a substrate;

a pixel portion comprising a plurality of pixel TFTs, a plurality of gate signal lines, a plurality of source signal lines, and a plurality of pixel electrodes formed over the substrate, the pixel TFTs and the pixel electrodes disposed on the respective portions where the gate signal lines and the source signal lines cross each other,

wherein each n-channel TFT of the driver TFTs has at least one LDD region (low-density imparity region) overlapping with a gate electrode thereof, and each of the pixel TFTs has LDD regions not overlapping with a gate electrode thereof,

wherein first video signals of the same polarity are supplied to said plurality of pixel electrodes through said plurality of source signal lines during a first frame period,

wherein second video signals of the polarity opposite to that of said first video signal are supplied to said plurality of pixel electrodes through said plurality of source signal lines during a second frame period subsequent to said first frame period, and

wherein a length of said first frame period and said second frame period is set to 8.3 msec or less.

2. A device according to claim 1, wherein intervals of said plurality of gate signal lines or said plurality of source signal lines are set to 20 μ

m or less.

3. A device according to claim 1, further comprising a second substrate having color filters of three colors.

4. A device according to claim 3, wherein each of said plurality of pixel electrodes corresponds to one of the three colors of said color filters.

5. A device according to claim 3, wherein liquid crystal is disposed between said substrate and said second substrate.

6. A goggle type display having a said display device according to claim 1.

7. A goggle type display having two display device according to claim 1.

8. A mobile computer having a display device according to claim 1.

9. A notebook type personal computer having a display device according to claim 1.

10. A video camera having a display device according to claim 1.

11. A DVD player having a display device according to claim 1.

12. A game machine having a display device according to claim 1.

13. A display device, comprising:

at least one driver circuit comprising a plurality of driver TFTs formed over a substrate;

a pixel portion comprising a plurality of pixel TFTs, a plurality of gate signal lines, a plurality of source signal lines, and a plurality of pixel electrodes formed over the substrate, the pixel TFTs and the pixel electrodes disposed on the respective portions where the gate signal lines and the source signal lines cross each other,

wherein each n-channel TFT of the driver TFTs has at least one LDD region (low-density imparity region) overlapping with a gate electrode thereof, and each of the pixel TFTs has LDD regions not overlapping with a gate electrode thereof,

wherein video signals of the same polarity are supplied to said plurality of pixel electrodes through said plurality of source signal lines,

wherein said polarity of said video signals changes for each one-frame period, and

wherein a length of said one-frame period is set to 8.3 msec or less.

14. A device according to claim 13, wherein intervals of said plurality of gate signal lines or said plurality of source signal lines are set to 20 μ

m or less.

15. A device according to claim 13, further comprising a second substrate having color filters of three colors.

16. A device according to claim 15, wherein each of said plurality of pixel electrodes corresponds to one of the three colors of said color filters.

17. A device according to claim 15, wherein liquid crystal is disposed between said substrate and said second substrate.

18. A goggle type display having a said display device according to claim 13.

19. A goggle type display having two display device according to claim 13.

20. A mobile computer having a display device according to claim 13.

21. A notebook type personal computer having a display device according to claim 13.

22. A video camera having a display device according to claim 13.

23. A DVD player having a display device according to claim 13.

24. A game machine having a display device according to claim 13.

25. A display device, comprising:

at least one driver circuit comprising a plurality of driver TFTs formed over a substrate;

a pixel portion comprising a plurality of pixel TFTs, a plurality of gate signal lines, a plurality of source signal lines, and a plurality of pixel electrodes formed over the substrate, the pixel TFTs and the pixel electrodes disposed on the respective portions where the gate signal lines and the source signal lines cross each other,

wherein each n-channel TFT of the driver TFTs has at least one LDD region (low-density imparity region) overlapping with a gate electrode thereof, and each of the pixel TFTs has LDD regions not overlapping with a gate electrode thereof,

wherein video signals of the same polarity are supplied to said plurality of switching elements through said plurality of source signal lines,

wherein select signals which select said video signals are supplied to said plurality of switching elements through said plurality of gate signal lines,

wherein video signals selected by said select signals are supplied to said plurality of pixel electrodes through said plurality of switching elements,

wherein said polarity of said video signal changes for each one-frame period, and

wherein a length of said one-frame period is set to 8.3 msec or less.

26. A device according to claim 25, wherein intervals of said plurality of gate signal lines or said plurality of source signal lines are set to 20 μ

m or less.

27. A device according to claim 25,

wherein one of said gate signal lines is connected to said gate electrode of the pixel TFT, and

wherein any one of said source signal lines is connected to one of source and drain regions of the pixel TFT.

28. A device according to claim 25, further comprising a second substrate having color filters of three colors.

29. A device according to claim 28, wherein each of said plurality of pixel electrodes corresponds to one of the three colors of said color filters.

30. A device according to claim 28, wherein liquid crystal is disposed between said substrate and said second substrate.

31. A goggle type display having a said display device according to claim 25.

32. A goggle type display having two display device according to claim 25.

33. A mobile computer having a display device according to claim 25.

34. A notebook type personal computer having a display device according to claim 25.

35. A video camera having a display device according to claim 25.

36. A DVD player having a display device according to claim 25.

37. A game machine having a display device according to claim 25.

38. A display device, comprising:

at least one driver circuit comprising a plurality of driver TFTs formed over a substrate;

a pixel portion comprising a plurality of pixel TFTs, a plurality of gate signal lines, a plurality of source signal lines, and a plurality of pixel electrodes formed over the substrate, the pixel TFTs and the pixel electrodes disposed on the respective portions where the gate signal lines and the source signal lines cross each other,

wherein each n-channel TFT of the driver TFTs has at least one LDD region (low-density imparity region) overlapping with a gate electrode thereof, and each of the pixel TFTs has LDD regions not overlapping with a gate electrode thereof,

wherein video signals of the same polarity are supplied to said plurality of pixel electrodes through said plurality of source signal lines,

wherein said polarity of said video signals changes for each one-frame period, and

wherein a frame frequency is set to 120 Hz or more.

39. A device according to claim 38, wherein intervals of said plurality of gate signal lines or said plurality of source signal lines are set to 20 μ

m or less.

40. A device according to claim 38, further comprising a second substrate having color filters of three colors.