Display device having a photosensor and a correction sensor
View Patent ↗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 photosensoris prevented.
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;
a correction sensor formed using a thin-film transistor is formed in the vicinity of the photosensor, and
a light-blocking film is formed over the thin-film transistor of the photosensor for blocking the outside light, wherein an opening part in the light-blocking film is defined only over a drain region of the thin-film transistor of the photosensor such that a photo-electric current is generated in the drain region of the thin-film transistor of the photosensor, and a light-blocking layer is formed over the thin-film transistor of the correction sensor for blocking the outside light.
2. The display device of claim 1 , wherein the photosensor and the correction sensor operate as a pair.
3. The display device of claim 1 , further comprising:
a plurality of photosensors formed using thin-film transistors being disposed on the substrate on an outside of the effective screen, each generating a signal as a result of outside light being blocked, the signals from the plurality of photosensors causing the display device to perform respective specified functions; and
a plurality of correction sensors formed using thin-film transistors being formed in the vicinity of the plurality of photosensors respectively,
wherein a light-blocking film is formed over the thin-film transistor of each of the plurality of photosensors for blocking the outside light, wherein an opening part in the light-blocking film is defined only over a respective drain region of each of the thin-film transistors of the plurality of photosensors such that a photo-electric current is generated in the respective drain region of each of the thin-film transistors of the plurality of photosensors, and a light-blocking layer is formed over the thin-film transistor of each of the plurality of correction sensors for blocking the outside light.
4. The display device of claim 1 , wherein the photosensor and the correction sensor are formed adjacent to each other.
5. The display device of claim 1 , wherein the photosensor and the correction sensor are formed by the same process as for the thin-film transistor corresponding to the pixels.
6. 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.
7. 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;
a correction sensor formed using a thin-film transistor is formed in the vicinity of the photosensor; and
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, wherein
an opening part in the light-blocking film is formed only in a drain region of the thin-film transistor constituting the photosensor such that a photo-electric current is generated in the drain region of the thin-film transistors constituting the photosensor.
8. The liquid crystal display device of claim 7 , wherein the photosensor and the correction sensor are formed by the same process as for the thin-film transistor used for the pixel electrode.
9. The liquid crystal display device of claim 7 , wherein the photosensor and the correction sensor operate as a pair.
10. The display device of claim 1 , wherein an organic EL layer is formed on the pixels.
11. 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.
12. The display device of claim 11 , wherein the thin-film transistor of the photosensor is connected in series with the thin-film transistor of the correction sensor.
13. The display device of claim 12 , further comprising an output line which outputs the signal, and a second thin-film transistor a drain or source of which is connected to the output line, wherein
the drain or source of the thin-film transistor of the photosensor is connected to the drain or source of the thin-film transistor of the correction sensor via a connecting line; and
a gate of the second thin-film transistor is connected to the connecting line.