Display device

• US 20070188431A1
• Filed: 08/03/2006
• Published: 08/16/2007
• Est. Priority Date: 08/05/2005
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takeuchi, Takeya, Sato, Tomohiko, Fukano, Tomoyuki, Itakura, Naoyuki
• Granted Patent: US 7,825,885 B2
• Time in Patent Office: Days
• US Class Current: 345/90
• CPC Class Codes: G09G 2310/0278 Details of driving circuits arranged to drive both scan and data electrodes
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• 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: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A display device having a pixel section pixel circuits, scan lines, capacity lines, a drive circuit driving the scan lines and the capacity lines selectively, a generation circuit generating a common voltage signal switching in level at a predetermined cycle, and a correction circuit correcting the signals driving the capacity lines of the drive circuit, wherein each pixel circuit contains a display element and holding capacitor, a first pixel electrode of the display element pixel cell, a first electrode of the holding capacitor, and one terminal of the switching element are connected, a second electrode of the holding capacitor is connected to the capacity lines arrayed in a corresponding row, and the common voltage signal is applied in a second pixel electrode of the display element. The correction circuit has a monitor circuit monitoring the pixel potential of the pixel section and correcting a signal driving the capacity lines taking into consideration the optical characteristics of the display element based on the monitor result of the monitor circuit.

Claims

1. A display device comprising:

a pixel section having a plurality of pixel circuits, each writing video pixel data propagated through a switching element over a signal line, arranged in a matrix,

a plurality of scan lines arranged so as to correspond to an array of rows of the pixel circuits and control conduction of the switching elements,

a plurality of capacity lines arranged so as to correspond to an array of rows of the pixel circuits,

a drive circuit for selectively driving the plurality of scan lines and the plurality of capacity lines,

a generation circuit for generating a common voltage signal switched in level at a predetermined cycle, and

a correction circuit for correcting the signals driving the capacity lines of the drive circuit, wherein

each pixel circuit arrayed at the pixel section includes

a display element having a first pixel electrode and second pixel electrode and

a holding capacitor having a first electrode and second electrode,

a first pixel electrode of the display element pixel cell and a first electrode of the holding capacitor are connected to one terminal of the switching element,

a second electrode of the storage capacitor is connected to the capacity line arrayed at a corresponding row,

a second pixel electrode of the display element is supplied with the common voltage signal, and

the correction circuit has a monitor circuit for monitoring the pixel potential of the pixel section and corrects the signals driving the capacity lines considering the optical characteristics of the display elements based on the results of monitoring of the monitor circuit.

2. A display device as set forth in claim 1, wherein the common voltage signal is a small amplitude signal.

3. A display device as set forth in claim 2, wherein the correction circuit performs weighting in accordance with temperature in the correction.

4. A display device as set forth in claim 3, wherein the correction circuit divides the temperature at a predetermined boundary into a high temperature region and low temperature region and performs different weighting in the two regions.

5. A display device as set forth in claim 4, wherein the correction circuit divides the temperature at a predetermined boundary into a high temperature region and low temperature region and sets the weighting value of the high temperature region to a value larger than the weighting value of the low temperature region in the correction.

6. A display device as set forth in claim 2, wherein the correction circuit performs rough adjustment and fine adjustment in a plurality of frames and selects a desired value.

7. A display device as set forth in claim 4, wherein the drive circuit drives the scan lines of the selected row, writes pixel data into the desired pixel circuits, and drives the capacity lines of the same row.

8. A display device as set forth in claim 7, wherein the drive circuit selects as a signal for driving a capacity line one of a first level and a second level lower than the first level and applies it to the corresponding capacity line.

9. A display device as set forth in claim 1, wherein the pixel circuit has display elements having liquid crystal cells.

10. A display device comprising:

a pixel section having a plurality of pixel circuits, each writing video pixel data propagated through a switching element over a signal line, arranged in a matrix,

a plurality of scan lines arranged so as to correspond to an array of rows of the pixel circuits and control conduction of the switching elements,

a plurality of capacity lines arranged so as to correspond to an array of rows of the pixel circuits,

a drive circuit for selectively driving the plurality of scan lines and the plurality of capacity lines,

a generation circuit for generating a common voltage signal switched in level at a predetermined cycle, and

a correction circuit for correcting the signals driving the capacity lines of the drive circuit, wherein

each pixel circuit arrayed at the pixel section includes

a display element having a first pixel electrode and second pixel electrode and

a holding capacitor having a first electrode and second electrode,

a first pixel electrode of the display element pixel cell and a first electrode of the holding capacitor are connected to one terminal of the switching element,

a second electrode of the holding capacitor is connected to the capacity line arrayed at a corresponding row,

a second pixel electrode of the display element is supplied with the common voltage signal, and

the drive circuit has a capacity line driver which drives a corresponding capacity line independently for each row based on a polarity signal at the time of a pixel write operation.

11. A display device as set forth in claim 10, wherein the common voltage signal is a small amplitude signal.

12. A display device as set forth in claim 11, wherein the drive circuit has a capacity line driver which determines a polarity of a signal driving a capacity line based on the polarity at the time of a pixel write operation.

13. A display device as set forth in claim 12, wherein

the drive circuit has a scan line driver including a shift register for shifting a predetermined signal in a column direction and a buffer receiving the signal of the shift register and driving the corresponding scan line, and

the capacity line driver includes a first latch latching the polarity signal based on an output signal of the shift register to the buffer and a second latch latching and outputting the polarity signal latched by the first latch based on a shift signal to a next stage of the shift register.

14. A display device as set forth in claim 13, wherein the drive circuit drives the scan lines of the selected row, writes pixel data into the desired pixel circuits, then drives the capacity lines of the same row.

15. A display device as set forth in claim 14, wherein the drive circuit selects as a signal for driving a capacity line one of a first level and a second level lower than the first level and applies it to the corresponding capacity line.

16. A display device as set forth in claim 11, wherein the pixel circuit has display elements including liquid crystal cells.

17. A display device comprising:

a pixel section having a plurality of pixel circuits, each writing video pixel data propagated through a switching element over a signal line, arranged in a matrix,

a plurality of scan lines arranged so as to correspond to an array of rows of the pixel circuits and control conduction of the switching elements,

a plurality of capacity lines arranged so as to correspond to an array of rows of the pixel circuits,

a first drive circuit for selectively driving the plurality of scan lines and the plurality of capacity lines from first ends,

a second drive circuit for selectively driving the plurality of scan lines and a plurality of the capacity lines among the plurality of capacity lines from other ends, and

a generation circuit for generating a common voltage signal switched in level at a predetermined cycle, wherein

each pixel circuit arrayed at the pixel section includes

a display element having a first pixel electrode and second pixel electrode and

a holding capacitor having a first electrode and second electrode,

a first pixel electrode of the display element pixel cell and a first electrode of the storage capacitor are connected to one terminal of the switching element,

a second electrode of the storage capacitor is connected to the capacity line arrayed at a corresponding row, and

a second pixel electrode of the display element is supplied with the common voltage signal.

18. A display device as set forth in claim 17, wherein the common voltage signal is a small amplitude signal.

19. A display device as set forth in claim 18, wherein the first and second drive circuits have capacity line drivers which drive the corresponding capacity lines independently for each row based on the polarity signal at the time of a pixel write operation.

20. A display device as set forth in claim 19, wherein the second drive circuit has a capacity line driver which drives corresponding capacity lines in response to a drive signal from the first drive circuit propagated through scan lines of the corresponding row.

21. A display device as set forth in claim 20, wherein each of the drive circuits drives the scan lines of the selected row, writes pixel data into the desired pixel circuits, then drives the capacity lines of the same row.

22. A display device as set forth in claim 21, wherein each of the drive circuits selects as a signal for driving a capacity line one of a first level and a second level lower than the first level and applies it to the corresponding capacity line.

23. A display device as set forth in claim 17, wherein the pixel circuit has display elements having liquid crystal cells.