IP Library Granted Patent US 8,334,862
Granted Patent B2
US 8,334,862 · App. 11/889,910 · Granted Dec 18, 2012

Display panel drive technique for reducing power consumption

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Quick Facts
Patent No.
US 8,334,862
App. No.
11/889,910
Granted
Dec 18, 2012
Kind
B2
Abstract

A method is provided for operating a display apparatus in which one source output of a source driver is connected with first to N-th data lines through first to N-th time division switches, which method includes: driving a first pixel positioned in a first horizontal line and connected with one of the first to N-th data lines, by feeding a first drive voltage to the one of the first to N-th data lines from the one source output with associated one of the first to N-th time division switches; and driving a second pixel positioned in a second horizontal line next to the first horizontal line and connected with the one of the first to N-th data lines, by feeding a second drive voltage to the one of the first to N-th data lines from the source output with associated one of the first to N-th time division switches. The associated one time division switch is kept turned on during a time period from a start time of the driving the first pixel to a start time of the driving the second pixel.

Claims (26)

1. A method of operating a display apparatus in which one source output of a source driver is connected with first to N-th data lines through first to N-th time division switches, said method comprising:

driving a first pixel positioned in a first horizontal line and connected with one of said first to N-th data lines, by feeding a first drive voltage to said one of said first to N-th data lines from said one source output with an associated one of said first to N-th time division switches turned on; and

driving a second pixel positioned in a second horizontal line next to said first horizontal line and connected with said one of said first to N-th data lines, by feeding a second drive voltage to said one of said first to N-th data lines from said source output with the associated one of said first to N-th time division switches,

wherein said associated one time division switch is kept turned on during a time period from a start time of said driving said first pixel to a start time of said driving said second pixel from a first horizontal period to a second horizontal period,

wherein a second time division switch is kept turned on through a transition from the second horizontal period to a third horizontal period such that at least one of the time division switches is kept turned on periodically for each transition of a horizontal period.

2. The method according to claim 1 , further comprising:

precharging said first to N-th data lines during a precharge period which is a part of said time period from said start time of said driving said first pixel to said start time of said driving said second pixel, by connecting said first to N-th data lines with a precharge line of a predetermined precharge voltage with said source output set to high impedance.

3. The method according to claim 1 , further comprising:

precharging said first to N-th data lines during a precharge period which is a part of said time period from said start time of said driving said first pixel to said start time of said driving said second pixel, by outputting a predetermined precharge voltage from said source output with said first to N-th time division switches turned on.

4. The method according to claim 1 , further comprising:

precharging said first to N-th data lines during a precharge period which is a part of said time period from said start time of said driving said first pixel to said start time of said driving said second pixel, by outputting a predetermined precharge voltage from said source output with said first to N-th data lines electrically connected through at least one neutralization switch.

5. The method according to claim 4 , wherein said first to N-th data lines are precharged with one(s) of said first to N-th time division switches other than said associated one of said first to N-th time division switches turned off.

6. The method according to claim 1 , wherein when a first to N-th output switches are turned to an off state, the one source output is set into a high impedance state.

7. The method according to claim 1 , wherein the associated one time division switch is kept turned on during a time period from a start time of said driving said first pixel to a start time of said driving said second pixel to reduce a total number of switchings performed by the first to N-th time division switches for a predetermined time period.

8. A display panel driver for driving a display panel including a plurality of pixels, first to N-th time division switches and first to N-th data lines disposed along columns of said plurality of pixels, respectively, the display panel driver comprising:

a source output adapted to be connected with said first to N-th data lines through said first to N-th time division switches;

a driver circuit adapted to output drive voltages for driving said plurality of pixels from said source output; and

a control circuit adapted to control said first to N-th time divisional switches,

wherein said control circuit turns on one of said first to N-th time division switches in a first drive period for driving a first pixel of said plurality of pixels, which is positioned in a first horizontal line and connected with one of said first to N-th data lines,

wherein said drive circuit drives said first pixel by feeding a first drive voltage from said source output to said first pixel through said one of said first to N-th time division switches in said first drive period,

wherein said control circuit turns on said one of said first to N-th time division switches in a second drive period for driving a second pixel of said plurality of pixels, which is positioned in a second horizontal line next to said first horizontal line and connected with said one of said first to N-th data lines,

wherein said drive circuit drives said second pixel by feeding a second drive voltage from said source output to said pixel through said one of said first to N-th time division switches in said second drive period, and

wherein said control circuit keeps said one of said first to N-th time division switches turned on during a time period from a timing when said first pixel starts to be driven to a timing when said second pixel stops being driven,

wherein a second time division switch is kept turned on through a transition from the second drive period to a third drive period such that at least one of the time division switches is kept turned on periodically for each transition of a drive period.

9. The display panel driver according to claim 8 , wherein when a first to N-th output switches are turned to an off state, the one source output is set into a high impedance state.

10. The display panel driver according to claim 8 , wherein the associated one time division switch is kept turned on during a time period from a start time of said driving said first pixel to a start time of said driving said second pixel to reduce a total number of switchings performed by the first to N-th time division switches for a predetermined time period.

Assignments (3)
CHANGE OF ADDRESS Recorded Nov 29, 2017
From: RENESAS ELECTRONICS CORPORATION
To: RENESAS ELECTRONICS CORPORATION
Reel/Frame 044928/0001 →
CHANGE OF NAME Recorded Nov 2, 2010
From: NEC ELECTRONICS CORPORATION
To: RENESAS ELECTRONICS CORPORATION
Reel/Frame 025235/0233 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 17, 2007
From: SHIRAI, HIROAKI
To: NEC ELECTRONICS CORPORATION
Reel/Frame 019758/0589 →