Liquid crystal display device

• US 6,618,033 B2
• Filed: 12/08/2000
• Issued: 09/09/2003
• Est. Priority Date: 12/08/1999
• 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: Takafuji, Yutaka
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Shapiro, Leonid
• Application Number:
  US09/731,815
• Publication Number:
  US 20010003446A1
• Time in Patent Office: 1,005 Days
• Field of Search: 345/96, 345/97, 345/92, 345/87, 345/88, 345/89, 345/84, 345/90, 345/55, 345/50, 349/5, 349/7, 349/106, 349/108, 349/110, 349/111
• US Class Current: 345/96
• CPC Class Codes: G02F 1/136218 Shield electrodes
• CPC Class Codes: G02F 2202/104 poly-Si
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• 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 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• 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

Abstract

In an active-matrix-driven LCD device, a driver circuit and a display section are formed on one substrate and in which each of thin-film transistors included in the driver circuit and display section has an active layer made of a polysilicon that has been formed by enhancing its crystal growth. The driver circuit operates to write data of a same polarity to all pixels of an entire one-frame screen but write data of different polarities to different frames adjoining each other on a time base at a frame frequency of about 100 Hz or more.

Claims

1. An active-matrix-driven LCD device comprising:

a driver circuit and a display section are formed on one substrate and in which each of thin-film transistors included in the driver circuit and/or display section has an active layer made of a polysilicon that has been formed by enhancing crystal growth thereof, wherein

the driver circuit operates to write data of a same polarity to all pixels of an entire one-frame screen but write data of different polarities to different frames adjoining each other on a time base at a frame frequency of about 100 Hz or more; and

a capacitance is provided between immediately adjacent pixel electrodes in a direction in which a source line extends, wherein the capacitance is of a value that falls within a range of 0.5 to 10% of a storage capacitance value.

3. The LCD device according to claim 1, wherein

the driver circuit comprises a data driver, and the LCD device further comprises an electrically shielding means provided between the source bus line and the pixel electrodes, the source bus line supplying data coming from the data driver to each of the pixel electrodes of the display section.

4. The LCD device according to claim 1, wherein

the driver circuit comprises a data driver which performs a dot sequential drive by which a plurality of parallelized data are simultaneously sampled.

5. The LCD device according to claim 1, wherein

an array pitch of the pixels in the display section is about 25 μ

m×

25 μ

m or less.

9. The LCD device of claim 1, further comprising an electrically conductive light-shield layer at least partially overlapping with the adjacent pixel electrodes, said conductive light-shield layer being in electrical communication with a drain of a thin film transistor corresponding to one of the pixel electrodes and disposed at least partially under the adjacent pixel electrodes with an insulating film interposed therebetween.

2. An active-matrix-driven LCD device comprising:

a driver circuit and a display section formed on one substrate, each of thin-film transistors included in the driver circuit and display section has an active layer comprising polysilicon that has been formed by enhancing crystal growth thereof;

wherein the driver circuit operates to write data of a same polarity to all pixels of an entire one-frame screen but write data of different polarities to different frames adjoining each other on a time base at a frame frequency of about 100 Hz or more;

a gate bus line and an auxiliary-capacitance common line disposed in parallel and spatially spaced from each other, and

a space between the gate bus line and the auxiliary-capacitance common line corresponding to an identical pixel forms a light transmitting portion usable for display.

10. The LCD device of claim 2, wherein the auxiliary-capacitance common line is used in forming the storage capacitance.

6. An active-matrix-driven LCD device comprising:

a driver circuit and a disphiy section, wherein the driver circuit operates to write data of a same polarity to all pixels of an entire one-frame screen but write data of different polarities to different frames adjoining each other on a time base, and

a capacitance provided between pixel electrodes adjoining each other along a source bus line in the display section, said capacitance including an inter-electrode capacitance between adjacent pixel electrodes and a capacitance given by an overlap of an electrically conductive light-shield layer with the adjacent pixel electrodes, said conductive light-shield layer being in electrical communication with a drain of a thin film transistor corresponding to one of the pixel electrodes and disposed at least partially under the adjacent pixel electrodes with an insulating film interposed therebetween.

7. An active-matrix-driven LCD device comprising:

a driver circuit and a display section, wherein the driver circuit operates to write data of a same polarity to all pixels of an entire one-frame screen but write data of different polarities to different frames adjoining each other on a time base, and

a capacitance provided between pixel electrodes adjoining each other along a source bus line in the display section, said capacitance including an inter-electrode capacitance between adjacent pixel electrodes and/or a capacitance given by an overlap of an electrically conductive light-shield layer with the adjacent pixel electrodes, said conductive light-shield layer being in electrical communication with a drain of a thin film transistor and disposed at least partially under the adjacent pixel electrodes with an insulating film interposed therebetween; and

wherein a space between the pixel electrodes adjoining each other in a direction in which the source bus line extends is about 15% or less of a length(s) along the source bus line of each of the pixel electrodes so that the inter-electrode capacitance between the adjoining pixel electrodes is obtained.

8. An active-matrix-driven LCD device comprising:

a driver circuit and a display section, wherein the driver circuit operates to write data of a same polarity to all pixels of an entire one-frame screen but write data of different polarities to different frames adjoining each other on a time base, and

a capacitance provided between pixel electrodes adjoining each other along a source bus line in the display section, said capacitance including an inter-electrode capacitance between adjacent pixel electrodes and/or a capacitance given by an overlap of an electrically conductive light-shield layer with the adjacent pixel electrodes, said conductive light-shield layer being in electrical communication with a drain of a thin film transistor and disposed at least partially under the adjacent pixel electrodes with an insulating film interposed therebetween; and

wherein the display section has a storage capacitance for each of the pixels, and

a capacitance between pixel electrodes adjacent each other in a direction in which the source bus line extends is within a range of not less than 0.5% but not more than 10% of a storage capacitance associated with the pixel electrodes including a parasitic capacitance.