DISPLAY APPARATUS AND METHOD OF DRIVING PIXEL THEREOF

• US 20120062135A1
• Filed: 09/08/2011
• Published: 03/15/2012
• Est. Priority Date: 09/13/2010
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tamaki, Junya, Sato, Nobuhiko
• Application Number:
  US13/228,148
• Publication Number:
  US 20120062135A1
• Time in Patent Office: Days
• US Class Current: 315/210
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/364 with use of subpixels
• CPC Class Codes: H05B 44/00 Circuit arrangements for operating electroluminescent light sources for operating light emitting diodes H05B45/00
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A display apparatus includes a plurality of pixels each including first and second organic EL elements whose emitting periods are controlled by respective emitting-period control TFTs. The second organic EL element has a front luminance lower than that of the first organic EL element. An electric charge charged in a storage capacitor as a gradation display signal in a previous frame is erased through an erasing TFT and the second organic EL element.

Claims

1. A method of driving a pixel of a display apparatus including a plurality of pixels,

wherein each of the plurality of pixels includes:

a plurality of sub-pixels of the same hue each composed of a respective organic electroluminescent element, an emitting-period control transistor that controls an emitting period of each of the organic electroluminescent elements, a driving transistor that supplies a current to the organic electroluminescent element through the emitting-period control transistor, a storage capacitor that is connected to a gate terminal of the driving transistor and that stores display information, and an erasing transistor that is connected between the storage capacitor and a route from the driving transistor to the emitting-period control transistor, and

wherein the plurality of sub-pixels comprises a first sub-pixel and a second sub-pixel having a front luminance lower than that of the first sub-pixel,

the method comprising;

erasing display information stored in the storage capacitor as a gradation display signal in a previous frame in the pixel through the organic electroluminescent element of the second sub-pixel of the plurality of sub-pixels included in the pixel.

2. The method of driving a pixel of a display apparatus according to claim 1, wherein the first sub-pixel includes a condensing lens.

3. A display apparatus comprising:

a plurality of pixels,

wherein each of the plurality of pixels includes;

a plurality of sub-pixels of the same hue each composed of a respective organic electroluminescent element, an emitting-period control transistor that controls an emitting period of each of the organic electroluminescent elements, a driving transistor that supplies a current to the organic electroluminescent element through the emitting-period control transistor, a storage capacitor that is connected to a gate terminal of the driving transistor and that stores display information, and an erasing transistor that is connected between the storage capacitor and a route from the driving transistor to the emitting-period control transistor,

wherein the plurality of sub-pixels comprises a first sub-pixel and a second sub-pixel having a front luminance lower than that of the first sub-pixel, and

wherein display information stored in the storage capacitor as a gradation display signal in a previous frame in the pixel is erased through the organic electroluminescent element of the second sub-pixel of the plurality of sub-pixels included in the pixel.

4. The display apparatus according to claim 3, wherein the first sub-pixel includes a condensing lens.