Active matrix display panel and image display device adapting same

• US 6,937,220 B2
• Filed: 09/23/2002
• Issued: 08/30/2005
• Est. Priority Date: 09/25/2001
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kitaura, Kazuo, Washio, Hajime
• Primary Examiner(s): Shankar, Vijay
• Assistant Examiner(s): DHARIA, PRABODH M
• Application Number:
  US10/251,857
• Publication Number:
  US 20030058231A1
• Time in Patent Office: 1,072 Days
• Field of Search: 345/90, 345/97, 345/92, 345/98, 345/32, 345/76, 345/80, 345/87, 345/100, 345204-206, 345/101, 349/33, 349/42, 349/48, 349/143, 359/54, 359/55, 359/59, 315/169.4, 315/169, 257/72
• US Class Current: 345/90
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2340/0492 Change of orientation of the displayed image, e.g. upside-down, mirrored
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

An active matrix display panel has (1) a plurality of row electrode lines; (2) a plurality of column electrode lines; (3) a first MOS transistor for each pixel; and (4) a second MOS transistor for each pixel. The first MOS transistor has (a) a first terminal connected to each of the column electrode line, (b) a second terminal connected to a liquid crystal, (c) a control terminal connected to each of the row electrode line, wherein an ON potential is higher than a signal potential supplied to the row electrode line. The second MOS transistor has (a) a first terminal connected to each of the row electrode line, (b) a second terminal connected to the electro-optic element, and (c) a control terminal connected to the column electrode line, wherein an ON potential is higher than a signal potential supplied to the column electrode line.

Claims

1. An active matrix display panel comprising:

a plurality of row electrode lines;

a plurality of column electrode lines arranged in a matrix with respect to said row electrode lines;

a pixel including an electro-optic element, arranged in a vicinity of each intersection of said row electrode lines and said column electrode lines;

a first switching element provided to each of the pixels, having (a) a first terminal connected to one of said column electrode lines, (b) a second terminal connected to said electro-optic element, and (c) a control terminal for ON/OFF control connected to one of said row electrode lines, wherein an ON potential at which said first switching element is switched ON when the potential is supplied to the control terminal is higher than a signal potential supplied to said row electrode line; and

a second switching element provided to each of the pixels, having (a) a first terminal connected to the one of said row electrode lines, (b) a second terminal connected to said electro-optic element, and (c) a control terminal for ON/OFF control connected to the one of said column electrode lines, wherein an ON potential at which said second switching element is switched ON when the potential is supplied to the control terminal is higher than a signal potential supplied to said column electrode line.

2. The active matrix display panel as set forth in claim 1, wherein:

the control terminal of said first switching element is connected to said row electrode line of a pixel at which said first switching element is provided or said row electrode line of a pixel adjacent to the pixel; and

the control terminal of said second switching element is connected to said column electrode line of a pixel at which said second switching element is provided or said column electrode line of a pixel adjacent to the pixel.

3. The active matrix display panel as set forth in claim 1, wherein:

said electro-optic element comprises a liquid crystal element.

4. The active matrix display panel as set forth in claim 1, wherein:

said electro-optic element comprises an organic electroluminescence element.

5. The active matrix display panel as set forth in claim 1, wherein:

said first and second switching elements are a thin film transistor comprised of polycrystalline silicon.

6. The active matrix display panel as set forth in claim 1, wherein:

said first and second switching elements are a thin film transistor comprised of continuous grain silicon.

7. An image display device having said active matrix display panel as set forth in claim 1, wherein:

one end of each of said column electrode lines is connected to a first source drive circuit, and another end of each of said column electrode lines is connected to a second gate drive circuit; and

one end of each of said row electrode lines is connected to a first gate drive circuit, and another end of each of said row electrode lines is connected to a second source drive circuit,

wherein said first and second source drive circuits and said first and second gate drive circuits have high output impedance in inactive states.

8. The image display device as set forth in claim 7, wherein:

said active matrix display panel is in a square shape;

said first source drive circuit and said second source drive circuit are respectively provided along adjacent sides of said active matrix display panel; and

data signal line systems of said first and second source drive circuits are connected with each other via a data signal line.

9. The image display device as set forth in claim 7, wherein:

said active matrix display panel is in a square shape;

said first gate drive circuit and said second gate drive circuit are respectively provided along adjacent sides of said active matrix display panel; and

address signal line systems of said first and second gate drive circuits are connected with each other via an address signal line.

10. The image display device as set forth in claim 7, comprising:

control means (a) for activating a pair of said first source and gate drive circuits and for inactivating a pair of said second source and gate drive circuits while said active matrix display panel displays an erect image, and (b) for inactivating the pair of said first source and gate drive circuits and for activating the pair of said second source and gate drive circuits while said active matrix display panel displays an image which rotated the erect image 90 degrees.

11. The image display device as set forth in claim 7, wherein:

said row electrode lines are gate bus lines and said column electrode lines are source bus lines while a pair of said first source and gate drive circuits are operated and a pair of said second source and gate drive circuits are not operated; and

said row electrode lines are source bus lines and said column electrode lines are gate bus lines while the pair of said first source and gate drive circuits are not operated and the pair of said second source and gate drive circuits are operated.

12. The image display device as set forth in claim 7, wherein:

said first and second switching elements are a thin film transistor composed of continuous grain silicon; and

a transistor comprising said first and second source drive circuits and said first and second gate drive circuits are made of continuous grain silicon.

13. The image display device as set forth in claim 7, comprising:

a controller (a) for activating a pair of said first source and gate drive circuits and for inactivating a pair of said second source and gate drive circuits while said active matrix display panel displays on erect image, and (b) for inactivating the pair of said first source and gate drive circuits and for activating the pair of said second source and gate drive circuits while said active matrix display panel displays an image which rotated the erect image 90 degrees.

14. An active matrix display panel comprising:

a plurality of row electrode lines and a plurality of column electrode lines arranged in a matrix, each of the row and column electrode lines functioning as a source bus line and a gate bus line; and

a pixel including an electro-optic element, arranged in a vicinity of an intersection of one of said row electrode lines and one of said column electrode lines,

wherein each pixel includes;

a first switching element which operates as a switching element for driving the pixel while the one said row electrode line is the gate bus line and the one said column electrode line is the source bus line; and

a second switching element which operates as a switching element for driving the pixel while the one said row electrode line is the source bus line and the one said column electrode line is the gate bus line.

15. The active matrix display panel as set forth in claim 14, wherein:

said second switching element is switched OFF while said first switching element is switched ON; and

said first switching element is switched OFF while said second switching element is switched ON.

16. The active matrix display panel as set forth in claim 14, wherein:

said first switching element has (a) a first terminal connected to one of said column electrode lines, (b) a second terminal connected to said electro-optic element, and (c) a control terminal for ON/OFF control connected to one of said row electrode lines, wherein an ON potential at which said first switching element is switched ON when the potential is supplied to the control terminal is higher than a signal potential supplied to said row electrode line.

17. The active matrix display panel as set forth in claim 14, wherein:

said second switching element has (a) a first terminal connected to the one of said row electrode lines, (b) a second terminal connected to said electro-optic element, and (c) a control terminal for ON/OFF control connected to the one of said column electrode lines, wherein an ON potential at which said second switching element is switched ON when the potential is supplied to the control terminal is higher than a signal potential supplied to said column electrode line.

18. An image display device having said active matrix display panel as set forth in claim 14, wherein:

one end of each of said column electrode lines is connected to a first source drive circuit, and another end of each of said column electrode lines is connected to a second gate drive circuit; and

one end of each of said row electrode lines is connected to a first gate drive circuit, and another end of each of said row electrode lines is connected to a second source drive circuit.

19. The image display device as set forth in claim 18, wherein:

said first and second source drive circuits and said first and second gate drive circuits have high output impedance in inactive states.