Light emitting display apparatus

• US 8,592,815 B2
• Filed: 06/30/2009
• Issued: 11/26/2013
• Est. Priority Date: 07/03/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tateishi, Yoshinori, Ofuji, Masato, Kumomi, Hideya, Hayashi, Ryo
• Primary Examiner(s): Lee, Hsien Ming
• Application Number:
  US13/001,000
• Publication Number:
  US 20110101346A1
• Time in Patent Office: 1,610 Days
• Field of Search: 438/22, 438/24, 438/29, 438/34, 438/39, 257/43, 257/59, 257/72, 257/81, 257/83, 257/222
• US Class Current: 257/59
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/78633 with a light shield
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs

Abstract

There is provided a light emitting display apparatus including at least a light emitting element and a thin film transistor (TFT) for driving the light emitting element, characterized in that a mechanism is provided in which a semiconductor constituting the TFT is irradiated with at least a part of light whose wavelength is longer than a predetermined wavelength among the light emitted by the light emitting element.

Claims

1. A light emitting display apparatus including at least a light emitting element and a thin film transistor (TFT) for driving the light emitting element, the apparatus comprising:

a mechanism including a light transmission region configured to irradiate, onto a semiconductor constituting the TFT, with at least a part of light whose wavelength is longer than a predetermined wavelength among the light emitted by the light emitting element,

wherein a light shielding film is provided between the light emitting element and the semiconductor, and

wherein an areal ratio of the light transmission region to the light shielding film is determined from the wavelength of the light emitted by the light emitting element.

2. The light emitting display apparatus according to claim 1, wherein the wavelength of the light with which the semiconductor constituting the TFT is irradiated is longer than an absorption edge wavelength of the semiconductor.

3. The light emitting display apparatus according to claim 1, further comprising a unit for shielding the semiconductor from the light whose wavelength is shorter than an absorption edge wavelength of the semiconductor.

4. The light emitting display apparatus according to claim 3, wherein the shielding unit is a color filter.

5. The light emitting display apparatus according to claim 1, wherein a surface density of in-gap level of the semiconductor is 10¹³ cm⁻

2 eV<sup>−

1</sup> or less.

6. The light emitting display apparatus according to claim 1, wherein the semiconductor is an oxide semiconductor including one of In, Ga, Zn and Sn.

7. The light emitting display apparatus according to claim 1, wherein the TFT at least includes a gate electrode formed on a substrate, an insulating film formed to cover the gate electrode, a semiconductor formed on the insulating film and a source electrode and a drain electrode formed on the semiconductor,

and

the mechanism includes the light transmissive region formed in at least a part of the light shielding film.

8. The light emitting display apparatus according to claim 7, wherein the light transmissive region is a slit.

9. The light emitting display apparatus according to claim 1, wherein the mechanism is a reflector that reflects at least a part of light whose wavelength is longer than a predetermined wavelength among the light emitted by the light emitting element and provided in a position where the reflector can reflect the light to the semiconductor of the TFT.

10. The light emitting display apparatus according to claim 1, wherein the TFT includes at least a source and drain electrodes formed over a substrate, the semiconductor formed to extend over the source and drain electrodes, an insulating film formed to cover the semiconductor and a gate electrode formed on the insulating film, and

the mechanism includes the light transmissive region provided in at least a part of the gate electrode.