Organic EL Display Device

• US 20080252223A1
• Filed: 03/13/2008
• Published: 10/16/2008
• Est. Priority Date: 03/16/2007
• Status: Abandoned Application

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Kasai, Naruhiko, Murakami, Hajime, Toyoda, Hironori
• Application Number:
  US12/047,337
• Publication Number:
  US 20080252223A1
• Time in Patent Office: Days
• US Class Current: 315/169.3
• CPC Class Codes: G09G 2300/043 Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements

Abstract

The present invention provides an organic EL display device with high detection accuracy which can enhance both of light emission efficiency and light reception efficiency. In an organic EL display device which includes organic thin film elements, a power source line is connected to the organic thin film elements via drive TFTs, a signal line is connected to a gate of the drive TFT to supply a potential corresponding to a gray scale signal, a switch is provided for connecting the signal line and the organic thin film element, and the switch is controlled to allow an electric current which is obtained by photoelectric conversion with the organic thin film element to flow in the signal line and the organic thin film element during a period in which a gray scale signal is not applied to the signal line.

Claims

1. An organic EL display device forming a plurality of pixels in a display region, wherein

the pixel includes a signal line, a capacitor, a first switch, a second switch, a power source line, and an organic thin film element,

the organic thin film element includes a pixel electrode which is separated for every pixel, a counter electrode overlapping with the pixel electrode, and an organic layer sandwiched between the pixel electrode and the counter electrode,

a gray-scale signal is supplied to the signal line,

a potential difference corresponding to the gray scale signal is held in the capacitor,

a first switch which controls a quantity of electric current flowing between the power source line and the organic thin film element corresponding to the potential difference held by the capacitance is connected between the power source line and the organic thin film element,

a second switch is connected between the signal line and the power source line, and

the second switch is controlled to connect the signal line and the organic thin film element during a period in which the gray scale signal is not supplied to the signal line.

2. An organic EL display device comprising:

a drive circuit arranged outside a display region and outputting a gray-scale signal;

signal lines extending to the inside of the display region from the outside of the display region;

power source lines extending to the inside of the display region from the outside of the display region; and

a plurality of pixels arranged in the inside of the display region, wherein

the pixel includes a first switch and a second switch constituted of a thin film transistor and an organic thin film element,

the organic thin film element includes a pixel electrode which is separated for every pixel, a counter electrode overlapping with a plurality of pixel electrodes, and an organic layer sandwiched between the pixel electrode and the counter electrode,

the power source line is electrically connected with the organic thin film element via the first switch,

the signal line is electrically connected with a control terminal of the first switch,

the signal line is electrically connected with the organic thin film element via the second switch,

a gray scale signal is supplied to the signal line from the drive circuit during a first period, and

the second switch is turned on and a signal corresponding to an external light from the organic thin film element is supplied to the signal line during a second period different from the first period.

3. An organic EL display device comprising:

light emitting elements; and

light receiving element, wherein

the light emitting element includes a pair of electrodes and an organic layer sandwiched therebetween,

the light receiving element includes a pair of electrodes and an organic layer sandwiched therebetween, and

the organic layer of the light emitting element and the organic layer of the light receiving element differ from each other in the layered structure.

5. An organic EL display device according to claim 5, wherein the organic layer of the light receiving element includes a material layer equal to a portion of the organic layer of the light emitting element.

4. An organic EL display device according to claim 5, wherein the organic layer of the light receiving element is a layer which does not emit light with an external light.

6. An organic EL display device according to claim 5, wherein the light receiving elements are arranged within a display region surrounded by the light emitting elements in a matrix array.

7. An organic EL display device according to claim 5, wherein the light receiving elements are arranged outside an effective display region surrounded by the light emitting elements.

8. An organic EL display device according to claim 5, wherein the organic layer of the light emitting element includes an organic light emitting layer, and

the organic layer of the light receiving element is constituted of only a material layer different from the organic light emitting layer or includes a material layer made of the same material as the organic light emitting layer and having a layer thickness different from a layer thickness of the organic light emitting layer.