Liquid crystal display driving method/driving circuit capable of being driven with equal voltages

• US 7,038,649 B2
• Filed: 05/07/2002
• Issued: 05/02/2006
• Est. Priority Date: 10/15/1992
• Status: Expired due to Fees

• Current Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Original Assignee: Hitachi, Ltd., Hitachi Video & Information System Incorporated
• Inventors: Furuhashi, Tsutomu, Ikeda, Makiko, Futami, Toshio, Kasai, Naruhiko, Suzuki, Tetsuya
• Primary Examiner(s): CHANG, KENT WU
• Application Number:
  US10/139,266
• Publication Number:
  US 20020154086A1
• Time in Patent Office: 1,456 Days
• Field of Search: 345/96, 345/87, 345/92, 345/94, 345/205, 345/206, 345/98, 345/100, 345/95, 345/93
• US Class Current: 345/96
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• 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 2310/0281 Arrangement of scan or data electrode driver circuits at the periphery of a panel not inherent to a split matrix structure
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• 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 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• 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 3/3688 suitable for active matrices only

Abstract

A display apparatus comprising a plurality of pixel portions arranged in a matrix, a signal driver circuit which generates apply voltages corresponding to display data, and applies the apply voltages to the pixel portions, a scan driver circuit which applies a selecting voltage to selected ones of the pixel portions, and a level shifter circuit which converts a voltage level of the display data into a drive voltage level of the signal driver circuit, thereby producing level-shifted display data. The signal driver circuit generates the apply voltages based on the level-shifted display data.

Claims

1. A display apparatus comprising:

a plurality of pixel portions arranged in a matrix;

a controller which generates an alternating signal for control of alternating of polarity of voltages at the pixel portions;

a signal driver circuit which generates apply voltages on the basis of display data, and applies the apply voltages to the pixel portions;

a scan driver circuit which applies a selective voltage to selected ones of the pixel portions; and

a lever shifter circuit which converts a voltage level of the display data into a drive voltage level of the signal driver circuit based upon the alternating signal, thereby producing level-shifted display data;

wherein the signal driver circuit generates the apply voltages based upon the level-shifted display data.

2. A display apparatus according to claim 1, wherein the signal driver circuit includes a latch circuit which latches the level-shifted display data in line units.

3. A display apparatus according to claim 1, wherein the controller generates a signal driver circuit timing signal for driving the signal driver circuit, and a scan driver circuit timing signal for driving the scan driver circuit.

4. A display apparatus according to claim 3, wherein the level shift circuit converts a voltage level of said signal driver circuit timing signal into the driving voltage level of the signal driver circuit.

5. A display apparatus according to claim 1, wherein the signal driver circuit is a low-voltage drain driver which is capable of generating, for each of the pixel portions, a voltage representing the luminance of the pixel portion and having either positive polarity or negative polarity.

6. a display apparatus according to claim 5, wherein polarity of voltages at the pixel portions is alternated by the alternating signal at frame internals.

7. A display apparatus according to claim 5, wherein the pixel portions are grounded into lines of pixel portions;

and

wherein the low-voltage drain driver changes a polarity of the voltage representing the luminance of the pixel portion for pixel portions in each of the lines of pixel portions.

8. A display apparatus according to claim 1, further comprising a polarity inverting circuits which periodically invert a polarity of the display data.

9. A display apparatus according to claim 1, wherein the scan driver circuit applies the selected voltage to the selected ones of the pixel portions in one line period of a frame period, and applies a non-selective voltage to the selected ones of the pixel portions in the one frame period for the one line period.

10. A display apparatus according to claim 1, wherein said display apparatus is a liquid crystal display apparatus.

14. A display apparatus according to claim 1, wherein the level shifter circuit converts a voltage level of the display data into a first drive voltage level of the signal driver circuit when the alternating signal indicates that the polarity of the voltage at the pixel portions is positive, and into a second drive voltage level of the signal driver circuit when the alternating signal indicates that the polarity of the voltage at the pixel portions is negative.

15. A display apparatus according to claim 14, wherein the first drive voltage level is higher than the second drive voltage level.

16. A display apparatus according to claim 14, wherein the first drive voltage level is lower than the second drive voltage level.

11. A display apparatus comprising:

a plurality of pixel portions arranged in a matrix;

a signal driver circuit which generates apply voltages corresponding to display data, and applies the apply voltages to the pixel portions;

a scan driver circuit which applies a selective voltage to selected ones of the pixel portions; and

a level shifter circuit which shifts a voltage level of the display area,

wherein a polarity of the voltage at the pixel portions is periodically changed, and

wherein the level shifter circuit converts a voltage level of the display data into a drive voltage level of the signal driver circuit based upon the polarity of the voltage at the pixel portions, thereby producing level-shifted display data.

12. A display apparatus according to claim 11, further comprising a reference voltage generating circuit which generates a reference voltage;

wherein the level shifter circuit shifts the voltage level of the display data using the reference voltage.

13. A display apparatus according to claim 12, wherein the level shifter circuit shifts the voltage level of the display data by adding the reference voltage to the display data.

17. A display apparatus according to claim 11, wherein the polarity of the voltage at the pixel portions is changed in one frame period.

18. A display apparatus according to claim 11,

wherein the reference voltage includes a first reference voltage in a case that the polarity of the voltage at the pixel portions is positive and a second reference voltage in a case that the polarity of the voltage at the pixel portions is negative, and

wherein the level shifter circuit shifts the voltage level of the display data using the first reference voltage when the polarity of the voltage at the pixel portions is positive, and shifts the voltage level of the display data using the second reference voltage when the polarity of the voltage at the pixel portions is negative.

19. A display apparatus according to claim 18, wherein the first reference voltage is higher than the second reference voltage.

20. A display apparatus according to claim 18, wherein the first reference voltage is lower than the second reference voltage.