Image display device

• US 20050225546A1
• Filed: 03/31/2005
• Published: 10/13/2005
• Est. Priority Date: 04/07/2004
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Akimoto, Hajime
• Granted Patent: US 7,786,986 B2
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2360/14 Detecting light within display terminals, e.g. using a single or a plurality of photosensors
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

The invention is to provided an integrated, optical touch panel type image display device free from crosstalk with displayed images. The image display device according to the invention comprises a plurality of pixels having display brightness modulation means controlled with display signals, a display unit in which the plurality of pixels are arrayed, and a plurality of optical detecting means provided within the display unit wherein each of the optical detecting means comprises an optical detection diode for converting incident lights into signal electric-carriers, signal electric-carrier resetting means for resetting the signal electric-carriers, and output impedance modulating means for detecting the signal electric-carriers and modulating output impedances. The output impedance modulating means in the optical detecting elements are connected, in series between each other, to a Y output line and an X output line.

Claims

1. An image display device comprising:

a plurality of pixels having display brightness modulation means controlled with display signals,

a display unit in which said plurality of pixels are arrayed, and

a plurality of optical detecting means provided within said display unit, wherein;

each of said optical detecting means comprises optical sense means for converting incident lights into signal electric-carriers, signal electric-carrier resetting means for resetting said signal electric-carriers, output impedance modulating means for detecting said signal electric-carriers and modulating output impedances, and

the output impedance modulating means of said plurality of optical detecting means are connected in series to each other.

2. The image display device according to claim 1, wherein:

said optical sense means is comprised of a TFT.

3. The image display device according to claim 1, wherein:

said optical sense means is comprised of a diode.

4. The image display device according to claim 1, wherein:

said signal electric-carrier resetting means is comprised of a TFT.

5. The image display device according to claim 4, wherein:

said optical sense means and said signal electric-carrier resetting means are composed by sharing the same TFT.

6. The image display device according to claim 1, wherein:

said output impedance modulating means is comprised of a TFT to whose gate said signal electric-carriers are inputted and which outputs the output impedance between its drain and source terminals.

7. The image display device according to claim 6, wherein:

said output impedance modulating means is comprised of an n-channel TFT.

8. The image display device according to claim 6, wherein:

said output impedance modulating means is comprised of a p-channel TFT.

9. The image display device according to claim 1, wherein:

one end of each of said plurality of output impedance modulating means connected in series is connected to a DC voltage source, and another end is connected to a display position detection circuit via a scanning circuit.

10. The image display device according to claim 1, wherein:

said plurality of output impedance modulating means are connected in series in the row and column directions.

11. The image display device according to claim 1, wherein:

the display brightness of said plurality of pixels is uniform when said optical detecting means are driven.

12. The image display device according to claim 11, wherein:

the display brightness of said plurality of pixels is at its maximum when optical detecting means are driven.

13. The image display device according to claim 11, wherein:

the display brightness of said plurality of pixels is at its minimum when said optical detecting means is driven.

14. The image display device according to claim 1, wherein:

each of said plurality of pixels uses an organic EL element for light emission.

15. The image display device according to claim 14, wherein:

said image display device consecutively performs, within one frame period, writing of display signals into each of said pixels, light emitting display of pixels, and optical detection.

16. The image display device according to claim 14, wherein:

a power source for said organic EL element is used in common with said signal electric-carrier resetting means.

17. The image display device according to claim 1, wherein:

each of said plurality of pixel modulates the emission of back light by using a liquid crystal element.

18. An image display device comprising:

memory means for holding input data,

display signal generating means for generating displays on the basis of said data,

a plurality of pixels having display brightness modulation means controlled with said display signals,

a display unit in which said plurality of pixels are arrayed, and

a plurality of optical detecting means provided within said display unit, wherein;

each of said plurality of optical detecting means has;

optical sense means for converting incident lights into signal electric-carriers,

signal electric-carrier resetting means for resetting said signal electric-carriers,

output impedance modulating means for detecting said signal electric-carriers and modulating output impedances, and

the output impedance modulating means of said plurality of optical detecting means are connected in series to each other.

19. The image display device according to claim 18, wherein:

said incident light position within the display unit is detected on the basis of the output result of said optical detecting means, and said display signals are altered on the basis of input information on said incident light position.