Display panel and display device

• US 9,184,408 B2
• Filed: 12/20/2012
• Issued: 11/10/2015
• Est. Priority Date: 04/19/2012
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Saito, Nobuyoshi, Ueda, Tomomasa, Yamaguchi, Hajime, Miura, Kentaro, Nakano, Shintaro, Sakano, Tatsunori
• Primary Examiner(s): Dickey, Thomas L
• Application Number:
  US13/721,925
• Publication Number:
  US 20130277646A1
• Time in Patent Office: 1,055 Days
• Field of Search: 257/40, 257/72, 313/498, 349/114
• US Class Current: 1/1
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 59/121 characterised by the geometry or disposition of pixel elements
• CPC Class Codes: H10K 59/60 OLEDs integrated with inorganic light-sensitive elements, e.g. with inorganic solar cells or inorganic photodiodes

Abstract

According to one embodiment, a display panel includes a substrate, a switching element, a pixel electrode, an organic light emitting layer, an opposite electrode, a detecting electrode, and an insulating layer. The substrate has a major surface. The switching element is provided on the major surface. The switching element includes a semiconductor layer. The pixel electrode is provided on the major surface. The pixel electrode is electrically connected to the switching element. The organic light emitting layer is provided on the pixel electrode. The opposite electrode is provided on the organic light emitting layer. The detecting electrode is provided between the substrate and at least a part of the pixel electrode. The detecting electrode includes at least one element included in the semiconductor layer. The insulating layer is provided between the pixel electrode and the detecting electrode.

Claims

1. A display panel comprising:

a substrate having a major surface, the substrate being light transmissive;

a switching element provided on the major surface and including a semiconductor layer;

a pixel electrode provided on the major surface and electrically connected to the switching element, the pixel electrode being light transmissive;

an organic light emitting layer provided on the pixel electrode;

an opposite electrode provided on the organic light emitting layer;

a detecting electrode provided between the substrate and at least a part of the pixel electrode and including at least one element included in the semiconductor layer, the detecting electrode being light transmissive;

an insulating layer provided between the pixel electrode and the detecting electrode, the insulating layer being light transmissive, the pixel electrode, the detecting electrode, and the insulating layer forming a detecting capacitor;

an amplifier transistor having a gate electrode, the gate electrode being electrically connected to the detecting capacitor; and

an output signal line being electrically connected to the amplifier transistor, the amplifier transistor passing a current depending on a capacitance of the detecting capacitor to the output signal line,

wherein the semiconductor layer and the detecting electrode each independently comprise an amorphous oxide which comprises at least one of In, Ga, and Zn.

2. The panel according to claim 1, wherein a difference between a distance between the detecting electrode and the substrate along a first direction perpendicular to the major surface and a distance between the semiconductor layer and the substrate along the first direction is 10 nm or less.

3. The panel according to claim 1, wherein a thickness of the semiconductor layer is 10 nm or more and 100 nm or less.

4. The panel according to claim 1, wherein

the insulating layer includes an organic layer, and

a thickness of the organic layer along a first direction perpendicular to the major surface is 1 μ

m or more 10 μ

m or less.

5. The panel according to claim 1, wherein

the insulating layer includes a contact layer contacting the detecting electrode, and

the contact layer includes at least one of a silicon oxide film, a silicon oxynitride film, and a silicon nitride film.

6. The panel according to claim 5, wherein the contact layer includes hydrogen at a concentration of 1×

10¹⁹ atoms/cm³ or more.

7. The panel according to claim 5, wherein a thickness of the contact layer is 100 nm or more and 200 nm or less.

8. The panel according to claim 1, wherein

the substrate includes at least one of a polyimide resin and an aramid resin, and

the substrate is flexible.

9. The panel according to claim 1, wherein the opposite electrode includes at least one of Al and MgAg.

10. The panel according to claim 1, wherein a thickness of the opposite electrode is 5 nm or more 500 nm or less.

11. The panel according to claim 1, wherein the pixel electrode includes one of an ITO, an ITO/Ag/ITO stacked structure, and ZnO including Al.

12. The panel according to claim 1, wherein

the switching element includes

a gate electrode provided on the major surface,

a gate insulating film provided on the gate electrode,

the semiconductor layer provided on the gate insulating film, the semiconductor layer including a first region, a second region apart from the first region, and a third region provided between the first region and the second region,

a first conducting portion electrically connected to the first region and the pixel electrode, and

a second conducting portion provided apart from the first conducting portion and electrically connected to the second region.

13. The panel according to claim 12, wherein the detecting electrode is provided on the gate insulating film.

14. The panel according to claim 12, wherein

the switching element further includes a channel protection film provided at least on the third region.

15. The panel according to claim 1, further comprising a sealing layer provided on the opposite electrode,

the sealing layer including at least one of a silicon oxide film, a silicon oxynitride film, a silicon nitride film, alumina, and a tantalum oxide film.

16. The panel according to claim 1, wherein the semiconductor layer and the detecting electrode each independently comprise an amorphous oxide selected from the group consisting of an In—

Ga—

Zn—

O oxide semiconductor, an In—

Ga—

O oxide semiconductor, and an In—

Zn—

O oxide semiconductor.

17. The panel according to claim 1, wherein the semiconductor layer and the detecting electrode each comprise the same amorphous oxide.

18. A display device comprising:

a display panel including;

a substrate having a major surface, the substrate being light transmissive;

a switching element provided on the major surface and including a semiconductor layer;

a pixel electrode provided on the major surface and electrically connected to the switching element, the pixel electrode being light transmissive;

an organic light emitting layer provided on the pixel electrode;

an opposite electrode provided on the organic light emitting layer;

a detecting electrode provided between the substrate and at least a part of the pixel electrode and including at least one element included in the semiconductor layer, the detecting electrode being light transmissive;

an insulating layer provided between the pixel electrode and the detecting electrode, the insulating layer being light transmissive, the pixel electrode, the detecting electrode, and the insulating layer forming a detecting capacitor;

an amplifier transistor having a gate electrode, the gate electrode being electrically connected to the detecting capacitor;

an output signal line being electrically connected to the amplifier transistor, the amplifier transistor passing a current depending on a capacitance of the detecting capacitor to the output signal line; and

a control unit configured to control an operation of the switching element to control a light emitted from the organic light emitting layer and configured to detect a capacitance of a detecting capacitor formed of the pixel electrode, the detecting electrode, and the insulating film,

wherein the semiconductor layer and the detecting electrode each independently comprise an amorphous oxide which comprises at least one of In, Ga, and Zn.

19. The device according to claim 18, wherein the control unit inputs a signal to emit the light from the organic light emitting layer to the switching element, subsequent to the detecting the capacitance.

20. The device according to claim 19, wherein the control unit is configured to

input a first signal at a first timing to emit the light to the switching element;

and

input a second signal at a second timing to emit the light to the switching element, the second timing is after the first timing, and

the detecting is performed in a latter period between the first timing and the second timing.

21. The display device according to claim 18, wherein the semiconductor layer and the detecting electrode each independently comprise an amorphous oxide selected from the group consisting of an In—

Ga—

Zn—

O oxide semiconductor, an In—

Ga—

O oxide semiconductor, and an In—

Zn—

O oxide semiconductor.

22. The display device according to claim 18, wherein the semiconductor layer and the detecting electrode each comprise the same amorphous oxide.