Active matrix assembly with signal line crossing to equalize stray capacitance

• US 5,616,936 A
• Filed: 03/10/1995
• Issued: 04/01/1997
• Est. Priority Date: 05/17/1988
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Oshima, Hiroyuki, Misawa, Toshiyuki
• Primary Examiner(s): JACKSON JR, JEROME
• Application Number:
  US08/402,054
• Time in Patent Office: 753 Days
• Field of Search: 345/80, 345/99, 345/92, 257/72, 257/776, 359/85
• US Class Current: 257/72
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136254 Checking; Testing
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2330/12 Test circuits or failure detection circuits included in a display system, as permanent part thereof
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes
• 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 2224/48091 Arched
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 23/4825 for devices consisting of semiconductor layers on insulating or semi-insulating substrates, e.g. silicon on sapphire devices, i.e. SOS
• 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 29/78618 : characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/12032 : Schottky diode
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: Y10S 257/923 : with means to optimize electrical conductor current carrying capacity, e.g. particular conductor aspect ratio
• CPC Class Codes: Y10S 345/904 : Display with fail/safe testing feature

Abstract

An active matrix panel including a matrix of driving electrodes couples through thin film transistor switches to a corresponding source line and gate line and at least one of a driver circuit including complementary thin film transistors for driving the source and/or gate lines of the picture elements on the substrate. The thin film transistors of the active matrix have the same cross-sectional structure as the P-type or the N-type thin film transistors forming the driver circuit and are formed during the same patterning process.

Claims

1. An active matrix assembly for an electro-optical device comprising:

a picture element matrix, the picture element matrix including a plurality of source lines and a plurality of picture elements electrically coupled to the plurality of source lines; and

a source line driving circuit electrically coupled to the picture element matrix through the plurality of source lines, the source line driving circuit comprising a shift register, at least a first clock signal line and a second clock signal line and a signal bus electrically coupled to the picture element matrix and the source line driving circuit, wherein the first clock signal line crosses the second clock signal line at substantially center points of the first and second clock signal lines so as to substantially equalize an average distance between the first clock signal line and the signal bus and an average distance between the second clock signal line and the signal bus.

2. The active matrix assembly of claim 1, wherein each of the plurality of picture elements includes a thin film transistor as a switching element.

3. The active matrix assembly of claim 1, wherein a capacitance between the first clock signal line and the signal bus is substantially equal to a capacitance between the second clock signal line and the signal bus.

6. The active matrix assembly of claim 1, wherein a rising edge of a first clock signal transmitted on the first clock signal line occurs at substantially a same time as a falling edge of a second clock signal transmitted on the second clock signal line and a falling edge of the first clock signal occurs at substantially a same time as a rising edge of the second clock signal.

7. The active matrix assembly of claim 1, wherein the shift register of the source line driving circuit includes CMOS thin film transistors.

4. An active matrix assembly for an electro-optical device comprising:

a picture element matrix, the picture element matrix including a plurality of source lines and a plurality of picture elements coupled to the plurality of source lines; and

a source line driving circuit coupled to the picture element matrix through the plurality of source lines, the source line driving circuit comprising a shift register, at least a first clock signal line and a second clock signal line and a signal bus coupled to the picture element matrix and the source line driving circuit, wherein the first clock signal line crosses the second clock signal line at more than one point substantially equalizing an average distance between the first clock signal line and the signal bus and an average distance between the second clock signal line and the signal bus.

5. The active matrix assembly of claim 4, wherein a capacitance between the first clock signal line and the signal bus is substantially equal to a capacitance between the second clock signal line and the signal bus.

9. The active matrix assembly of claim 4, wherein each of the plurality of picture elements includes a thin film transistor as a switching element.

10. The active matrix assembly of claim 4, wherein a rising edge of a first clock signal transmitted on the first clock signal line occurs at substantially a same time as a falling edge of a second clock signal transmitted on the second clock signal line and a falling edge of the first clock signal occurs at substantially a same time as a rising edge of the second clock signal.

11. The active matrix assembly of claim 4, wherein the shift register of the source line driving circuit includes CMOS thin film transistors.

8. An active matrix assembly for an electro-optical device comprising:

a picture element matrix, the picture element matrix including a plurality of source lines and a plurality of picture elements coupled to the plurality of source lines; and

a source line driving circuit coupled to the picture element matrix through the plurality of source lines, the source line driving circuit comprising a shift register, at least a first clock signal line and a second clock signal line for driving the shift register, and a signal bus coupled to the picture element matrix and the source line driving circuit, wherein the first clock signal line crosses the second clock signal line so as to substantially equalize an average distance between the first clock signal line and the signal bus, and an average distance between the second clock signal line and the signal bus, and to substantially equalize a capacitance between the first clock signal line and the signal bus and a capacitance between the second clock signal line and the signal bus.

12. An active matrix assembly for an electro-optical device comprising:

A picture element matrix, the picture element matrix including a plurality of source lines and a plurality of picture elements electrically coupled to the plurality of source lines; and

a source line driving circuit electrically coupled to the picture element matrix through the plurality of source lines, the source line driving circuit comprising a shift register, at least a first clock signal line and a second clock signal line and a signal bus electrically coupled to the picture element matrix and the source line driving circuit, wherein the first clock signal line crosses the second clock signal line and a capacitance between the first clock signal line and the signal bus is substantially equal to a capacitance between the second clock signal line and the signal bus.

13. A projection type color display device including a light source, at least one light valve, and at least one projecting optical system for projecting a color image, the at least one light valve including a plurality of liquid crystal cells, wherein data signals are supplied to the plurality of liquid crystal cells through a plurality of field effect transistors arranged in a plurality of picture elements, the light valve comprising:

a picture element matrix, the picture element matrix including a plurality of source lines and a plurality of picture elements electrically coupled to the plurality of source lines; and

a source line driving circuit electrically coupled to the picture element matrix through the plurality of source lines, the source line driving circuit comprising a shift register, at least a first clock signal line and a second clock signal line and a signal bus electrically coupled to the picture element matrix and the source line driving circuit, wherein the first clock signal line crosses the second clock signal line and a capacitance between the first clock signal line and the signal bus is substantially equal to a capacitance between the second clock signal line and the signal bus.

14. The projection type color display device of claim 13, wherein each of the plurality of picture elements includes a thin film transistor as a switching element.

15. The projection type color display device of claim 13, wherein a rising edge of a first clock signal transmitted on the first clock signal line occurs at substantially a same time as a falling edge of a second clock signal transmitted on the second clock signal line and a falling edge of the first clock signal occurs at substantially a same time as a rising edge of the second clock signal.

16. The projection type color display device of claim 13, wherein the shift register of the source line driving circuit includes CMOS thin film transistors.