Electroluminescent display device

• US 7,289,088 B2
• Filed: 09/24/2004
• Issued: 10/30/2007
• Est. Priority Date: 09/30/2003
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsumoto, Shoichiro
• Primary Examiner(s): DHARIA, PRABODH M
• Application Number:
  US10/948,742
• Publication Number:
  US 20050093466A1
• Time in Patent Office: 1,131 Days
• Field of Search: 345/76, 345/77, 345/173, 345/35, 345/36, 345/158, 345178-183, 345/89, 315/169.3, 178/18.01, 178/18.03, 178 1805- 1807, 356/621, 353/122, 341/13, 250/205, 362/545
• US Class Current: 345/76
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An organic electroluminescent (EL) display device has a touch panel function and includes a display panel that has first and second light sources disposed along sides of the display portion and first and second light detecting portions disposed on sides of the display portion opposite the light sources. The display device includes a plurality of organic EL display elements disposed in a matrix on the display portion and a plurality of organic EL light source elements disposed in a row in each of the light source portions. The light detecting portions include a plurality of detection light sensors and a reference light sensor disposed in a row in each of the light detecting portions. The display device also includes a comparator that compares an output of the detection light sensors with the output of the reference light sensor.

Claims

1. An electroluminescent display device comprising:

a display portion comprising a plurality of display electroluminescent elements disposed in a matrix;

a first light source portion comprising a plurality of light source electroluminescent elements disposed along a first side of the display portion;

a first light detecting portion comprising a plurality of detection light sensors disposed along a side opposite from the first side;

a second light source portion comprising a plurality of light source electroluminescent elements disposed along a second side of the display portion;

a second light detecting portion comprising a plurality of detection light sensors disposed along a side opposite from the second side;

a reference light sensor disposed in the first light detecting portion or the second light detecting portion; and

a comparator connected to the reference light sensor and at least two of the detection light sensors of a corresponding light detecting portion in which the reference light sensor is disposed.

2. The electroluminescent display device of claim 1, wherein the display portion, the first and second light source portions and the first and second light detecting portions are disposed on a substrate.

3. The electroluminescent display device of claim 1, wherein each of the detection light sensors and the reference light sensor comprises a photodiode.

4. The electroluminescent display device of claim 1, wherein each of the detection light sensors and the reference light sensor comprises a plurality of photodiodes connected in parallel.

5. The electroluminescent display device of claim 1, wherein the electroluminescent display device is of active type having a switching element in each of the display electroluminescent elements, and the switching elements and the detection light sensors have a same structure.

6. The electroluminescent display device of claim 1, wherein the display electroluminescent elements and the light source electroluminescent elements have a same structure.

7. The electroluminescent display device of claim 1, wherein the detection light sensors and the reference light sensor have a same structure.

8. The electroluminescent display device of claim 1, further comprising a shift resistor that activates the detection light sensors sequentially.

9. An electroluminescent display device comprising:

a display portion comprising a plurality of display electroluminescent elements disposed in a matrix;

a first light source portion comprising a plurality of light source electroluminescent elements disposed along a first side of the display portion;

a first light detecting portion comprising a plurality of detection light sensors disposed along a side opposite from the first side;

a second light source portion comprising a plurality of light source electroluminescent elements disposed along a second side of the display portion;

a second light detecting portion comprising a plurality of detection light sensors disposed along a side opposite from the second side;

a pair of first light reflecting boards for leading light emitted by the first light source portion to the first light detecting portion;

a pair of second light reflecting boards for leading light emitted by the second light source portion to the second light detecting portion;

a reference light sensor disposed in the first light detecting portion or the second light detecting portion; and

a comparator connected to the reference light sensor and at least two of the detection light sensors of a corresponding light detecting portion in which the reference light sensor is disposed.

10. The electroluminescent display device of claim 9, wherein the display portion, the first and second light source portions and the first and second light detecting portions are disposed on a substrate.

11. The electroluminescent display device of claim 9, wherein each of the detection light sensors and the reference light sensor comprises a photodiode.

12. The electroluminescent display device of claim 9, wherein each of the detection light sensors and the reference light sensor comprises a plurality of photodiodes connected in parallel.

13. The electroluminescent display device of claim 9, wherein the electroluminescent display device is of active type having a switching element in each of the display electroluminescent elements, and the switching elements and the detection light sensors have a same structure.

14. The electroluminescent display device of claim 9, wherein the display electroluminescent elements and the light source electroluminescent elements have a same structure.

15. The electroluminescent display device of claim 9, wherein the detection light sensors and the reference light sensor have a same structure.

16. The electroluminescent display device of claim 9, further comprising a shift resistor that activates the detection light sensors sequentially.