DISPLAY DRIVER CIRCUIT, DISPLAY DEVICE, AND DISPLAY DRIVING METHOD

• US 20100128009A1
• Filed: 07/14/2008
• Published: 05/27/2010
• Est. Priority Date: 10/16/2007
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Sasaki, Yasushi, Okada, Atsushi
• Granted Patent: US 8,305,369 B2
• Time in Patent Office: Days
• US Class Current: 345/205
• 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 2310/08 Details of timing specific for flat panels, other than clock recovery
• 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 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2330/026 Arrangements or methods related to booting a display
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• 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 3/3677 suitable for active matrices only

Abstract

One embodiment of the present invention includes: a gate line drive circuit that outputs, in a horizontal scanning period which is sequentially allocated to each one of rows, a gate signal for turning on the switching element on one row; a source bus line drive circuit that outputs a source signal of which polarity is reversed in sync with the horizontal scanning period for each of the rows and of which polarity is opposite in an adjacent horizontal scanning period on one and the same row; a CS bus line drive circuit that outputs, after the horizontal scanning period for each of the rows, a CS signal of which potential is switched along a direction (from low level to high level or from high level to low level) determined according to the polarity of the source signal in the horizontal scanning period concerned, wherein the CS bus line drive circuit outputs the CS signal in a first frame so that a potential of the CS signal at a time of on-to-off switching of the switching element on the one row is different from a potential of a CS signal on an adjacent row. This eliminates the occurrence of lateral stripes in the first frame from which display corresponding to a video signal is started in CC driving premised on line inversion driving.

Claims

1. A display drive circuit for carrying out display with a tone corresponding to a potential of a pixel electrode by driving a display panel including a plurality of rows each including a scan signal line, a switching element that is turned on/off by the scan signal line, the pixel electrode connected to one end of the switching element, and a capacitive coupling interconnection capacitively-coupled to the pixel electrode, and further including a data signal line connected to the other end of the switching element on each of the rows,

the display drive circuit comprising:

a scan signal line drive circuit that outputs, in a horizontal scanning period which is sequentially allocated to the each of the rows, a scan signal for turning on the switching element on one row;

a data signal line drive circuit that outputs a data signal of which polarity is reversed in sync with the horizontal scanning period for the each of the rows and of which polarity is opposite in an adjacent horizontal scanning period on one and the same row;

a capacitive coupling interconnection drive circuit that outputs, after the horizontal scanning period for the each of the rows, a potential shift signal of which potential is switched between two potential levels along a direction determined according to the polarity of the data signal in the horizontal scanning period concerned, wherein

the capacitive coupling interconnection drive circuit outputs the potential shift signal, in a first vertical scanning period from which output of a data signal corresponding to a video image to be displayed is started, so that a potential of the potential shift signal at a time of on-to-off switching of the switching element on the one row is different from a potential of a potential shift signal on an adjacent row.

2. The display drive circuit according to claim 1, wherein

the capacitive coupling interconnection drive circuit outputs the potential shift signal so that the potential of the potential shift signal on the one row is different between when the switching element on the one row is turned on and when the switching element on a row subsequent to the one row is turned on.

3. The display drive circuit according to claim 2, wherein

the capacitive coupling interconnection drive circuit includes:

a first input section that receives a scan signal on the one row and a scan signal on a row subsequent to the one row;

a second input section that receives a polarity signal of which polarity is reversed in sync with the horizontal scanning period for the each of the rows, the polarity signal corresponding to the potential of the potential shift signal; and

an output section that outputs the potential shift signal on the one row, and

a first polarity of the polarity signal inputted to the second input section when the scan signal on the one row is inputted to the first input section is outputted as a first potential of the potential shift signal, while a second polarity of the polarity signal inputted to the second input section when the scan signal on the row subsequent to the one row is inputted to the first input section is outputted as a second potential of the potential shift signal.

4. The display drive circuit according to claim 3, wherein

the capacitive coupling interconnection drive circuit comprises D-latch circuits.

5. The display drive circuit according to claim 1, wherein

the capacitive coupling interconnection drive circuit outputs the potential shift signal so that a potential of the potential shift signal in an initial state is different between adjacent rows.

6. The display drive circuit according to claim 5, further comprising:

a control circuit that controls the signal line drive circuits and the capacitive coupling interconnection drive circuit,

the control circuit inputting to the capacitive coupling interconnection drive circuit a control signal which is different between the adjacent rows, the control signal corresponding to a polarity signal of which polarity is reversed in sync with the horizontal scanning period for the each of the rows, so that the potential of the potential shift signal in the initial state is different between the adjacent rows.

7. The display drive circuit according to claim 6, wherein

the control circuit outputs a first control signal if the polarity signal is of the first polarity when the scan signal on the one row is turned on in the first vertical scanning period, while the control circuit outputs a second control signal if the polarity signal is of the second polarity when the scan signal on the one row is turned on in the first vertical scanning period.

8. The display drive circuit according to claim 7, wherein

the capacitive coupling interconnection drive circuit comprises D-latch circuits, and

the control circuit inputs to the capacitive coupling interconnection drive circuit a reset signal as the first control signal if the polarity of the polarity signal when the scan signal on the one row is turned on in the first vertical scanning period is in low level, while the control circuit inputs to the capacitive coupling interconnection drive circuit a set signal as the second control signal if the polarity of the polarity signal when the scan signal on the one row is turned on in the first vertical scanning period is in high level.

9. The display drive circuit according to claim 6, wherein

the capacitive coupling interconnection drive circuit includes:

a first input section that receives a scan signal on a row subsequent to the one row;

a second input section that receives a polarity signal of which polarity is reversed in sync with the horizontal scanning period for the each of the rows, the polarity signal corresponding to the potential level of the potential shift signal; and

an output section that outputs the potential shift signal on the one row, and

the capacitive coupling interconnection drive circuit changes the potential of the potential shift signal in accordance with a polarity of the polarity signal inputted to the second input section when the scan signal on the row subsequent to the one row is inputted to the first input section.

10. A display device comprising a display drive circuit according to claim 1 and the display panel.

11. The display device according to claim 10, wherein

the display device is a liquid crystal display device.

12. A display driving method for carrying out display with a tone corresponding to a potential of a pixel electrode by driving a display panel including a plurality of rows each including a scan signal line, a switching element that is turned on/off by the scan signal line, the pixel electrode connected to one end of the switching element, and a capacitive coupling interconnection capacitively-coupled to the pixel electrode, and further including a data signal line connected to the other end of the switching element on each of the rows,

the display driving method comprising:

a scan signal line driving process of outputting, in a horizontal scanning period which is sequentially allocated to the each of the rows, a scan signal for turning on the switching element on one row;

a data signal line driving process of outputting a data signal of which polarity is reversed in sync with the horizontal scanning period for the each of the rows and of which polarity is opposite in an adjacent horizontal scanning period on one and the same row; and

a capacitive coupling interconnection driving process of outputting, after the horizontal scanning period for the each of the rows, a potential shift signal of which potential is switched between two potential levels along a direction determined according to the polarity of the data signal in the horizontal scanning period concerned, wherein

the capacitive coupling interconnection drive circuit outputs the potential shift signal, in a first vertical scanning period from which output of a data signal corresponding to a video image to be displayed is started, so that a potential of the potential shift signal at a time of on-to-off switching of the switching element on the one row is different from a potential of a potential shift signal on an adjacent row.