Display device

• US 20090002341A1
• Filed: 06/06/2008
• Published: 01/01/2009
• Est. Priority Date: 06/07/2007
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Japan Display Incorporated
• Inventors: Sato, Hideo, Nishitani, Shigeyuki, Saito, Teruaki
• Granted Patent: US 8,570,302 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens
• CPC Class Codes: H10K 59/60 OLEDs integrated with inorganic light-sensitive elements, e.g. with inorganic solar cells or inorganic photodiodes

Abstract

It is an object of the present invention to allow a specified function to be readily selected in a mobile telephone or the like without performing a complicated operation. A liquid crystal (30) is sandwiched between a TFT substrate (10) and a color filter substrate (20). A photosensor TFT (130) for selecting the function is disposed on the periphery of an effective screen of the TFT substrate (10). A window (24) is provided in a portion of the color filter substrate corresponding to the photosensor TFT (130), and the outside light is blocked as a result of the user touching a finger to the window. A signal from the photosensor is used for selecting the function. A correction sensor TFT (133) is disposed adjacent to the photosensor TFT (130), to thereby eliminating noise caused by the temperature distribution, stray light, or the like, and erroneous operation of the photosensor is prevented.

Claims

1. A display device having a substrate on which pixels are disposed in the form of a matrix on an effective screen, and an image signal applied to each of the pixels is controlled by a thin-film transistor corresponding to the respective pixels, wherein

a photosensor formed using a thin-film transistor is disposed on the substrate on an outside of the effective screen, the photosensor generates a signal as a result of outside light being blocked, and the signal from the photosensor causes the display device to perform a specified function;

and

a correction sensor formed using a thin-film transistor is formed in the vicinity of the photosensor.

2. The display device of claim 1, wherein a light-blocking layer for blocking the outside light is formed on the outside of the effective screen, the light-blocking layer is not formed in an area corresponding to the photosensor, and the light-blocking layer is formed in an area corresponding to the correction sensor.

3. The display device of claim 1, wherein the photosensor and the correction sensor are constructed using a thin-film transistor formed by the same process as for the thin-film transistor corresponding to each of the pixels.

4. The display device of claim 1, wherein the thin-film transistor of the photosensor has a diode structure in which a gate of the thin-film transistor of the photosensor is connected to a drain or source of the thin-film transistor of the photosensor, and the thin-film transistor of the correction sensor has a diode structure in which a gate of the thin-film transistor of the correction sensor is connected to a drain or source of the thin-film transistor of the correction sensor.

5. The display device of claim 1, wherein the thin-film transistor of the photosensor and the thin-film transistor of the correction sensor are the same size.

6. The display device of claim 1, wherein the photosensor and the correction sensor are formed adjacent to each other.

7. The display device of claim 1, wherein the photosensor and correction sensor are formed so as to constitute a mutual pair, and a plurality of these pairs are formed for each of the functions.

18. The display device of claim 1, wherein an organic EL layer is formed on the pixels.

8. A display device having a substrate on which pixels are disposed in the form of a matrix on an effective screen, and an image signal applied to each of the pixels is controlled by a thin-film transistor corresponding to the respective pixels, wherein

a photosensor formed using a thin-film transistor is disposed on the substrate on an outside of the effective screen, the photosensor generates a signal as a result of outside light being blocked, and the signal from the photosensor causes the display device to perform a specified function;

a correction sensor formed using a thin-film transistor is formed in the vicinity of the photosensor; and

the thin-film transistor of the photosensor is covered by a light-blocking layer for blocking the outside light, except for the drain part, and the thin-film transistor of the correction sensor is covered by a light-blocking layer for blocking the outside light.

9. The display device of claim 8, wherein the photosensor and the correction sensor operate as a pair.

10. The display device of claim 8, wherein a plurality of photosensors and correction sensors are formed for each function.

11. The display device of claim 8, wherein the photosensor and the correction sensor are formed adjacent to each other.

12. The display device of claim 8, wherein the photosensor and the correction sensor are formed by the same process as for the thin-film transistor corresponding to the pixels.

13. The display device of claim 8, wherein the thin-film transistor of the photosensor and the thin-film transistor of the correction sensor are the same size.

19. The display device of claim 8, wherein an organic EL layer is formed on the pixels.

14. A liquid crystal display device having a TFT substrate on which a pixel electrode and a thin-film transistor that controls a signal voltage applied to the pixel electrode are formed in an effective screen, a color filter substrate on which a color filter and a black matrix are formed in an effective screen, a liquid crystal display panel in which an image is formed using a liquid crystal sandwiched between the TFT substrate and the color filter substrate, and a backlight, wherein

a photosensor formed using a thin-film transistor is formed on the TFT substrate on an outside of the effective screen, the photosensor generates a signal as a result of outside light being blocked, and the signal from the photosensor causes the display device to perform a specified function;

and

a correction sensor formed using a thin-film transistor is formed in the vicinity of the photosensor.

15. The liquid crystal display device of claim 14, wherein the photosensor and the correction sensor are formed by the same process as for the thin-film transistor used for the pixel electrode.

16. The liquid crystal display device of claim 14, wherein a light-blocking film for blocking outside light is formed on the color filter substrate in a part corresponding to the photosensor and the correction sensor formed on the TFT substrate, and an opening part in the light-blocking film is formed in a drain part of the thin-film transistor constituting the photosensor.

17. The liquid crystal display device of claim 14, wherein the photosensor and the correction sensor operate as a pair.