US 7,612,749 B2Granted

Driving circuits for displays

AssigneesChi Mei Optoelectronics Corp., KYOCERA Corporation

InventorsFrank Robert Libsch, James Lawrence Sanford

Life of this patent

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Abstract

A pixel circuit includes a light emitting device, a storage device configured to represent a level of illumination, and a driving device used to drive the light emitting device. Configuring the storage device includes changing a voltage difference across the storage device to a level larger than a threshold voltage of the driving device. The driving device reduces driving of the light emitting device while the storage device is being configured. After the storage device has been configured, the driving device is permitted to drive the light emitting device to emit light having a luminance level corresponding to the level of illumination represented by the storage device.

Claims24

Dependent claims

A method of driving a pixel circuit that includes a light emitting device, a storage device, a driving device for driving the light emitting device, and a switch, the method comprising:

during a first time period, charging the storage device to cause the storage device to store a voltage level representing a threshold voltage of the driving device by flowing a current through the driving device and the switch;
after the first time period and before a second time period, switching the switch for reducing a current which is to flow to or from the light emitting device in the second time period;
during the second time period, charging the storage device to cause the storage device to store a voltage level representing a sum of a threshold voltage of the driving device and a data voltage representing a level of illumination of the light emitting device;
and
after the second time period, switching the switch to permit the driving device to drive the light emitting device based on the voltage level stored in the storage device.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/379,481Filed 4 Mar 2003
Published: US 2004/0174349 A19 Sep 2004
Granted: 3 Nov 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H10D 30/6734
Multi-gate TFTs: having gate electrodes arranged on both top and bottom sides of the channel, e.g. dual-gate TFTs
G09G 3/3233
Using an active matrix: with pixel circuitry controlling the current through the light-emitting element
H10D 86/00
Integrated devices formed in or on insulating or conducting substrates
G09G 2300/0819
Several active elements per pixel in active matrix panels: used for counteracting undesired variations, e.g. feedback or autozeroing

Family

US 2004/0174349 A1Pre-grant publication · published 9 Sep 2004
US 7,612,749 B2This patent

From the US filing history. Foreign family members aren’t listed.

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