Photo detector array with thin-film resistor-capacitor network for use with a display device

• US 7,960,679 B2
• Filed: 07/13/2007
• Issued: 06/14/2011
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Shanghai Xuanyang Electronic Technologies Inc.
• Original Assignee: Integrated Digital Technologies, Inc. (InterDigital, Inc.)
• Inventors: Fann, Sen-Shyong
• Primary Examiner(s): Le; Que T
• Assistant Examiner(s): BUI PHO, PASCAL M
• Application Number:
  US11/777,887
• Publication Number:
  US 20080087796A1
• Time in Patent Office: 1,432 Days
• Field of Search: 250/208.1, 250/214.1, 250/214.R, 345/92, 345/157, 345/158, 345173-175, 257/428, 257/431, 257/443, 257/444, 349/42, 178/18.01, 178/18.03, 178/18.09
• US Class Current: 250/214.00R
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: H01L 31/1136 the device being a metal-insulator-semiconductor field-effect transistor
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof

Abstract

A photo detector device configured for use with a display device, the photo detector device comprising a photosensitive transistor formed on a substrate of the display device, the photosensitive transistor being capable of detecting an optical signal and converting the optical signal into a current signal, and a converter formed on the substrate of the display device, the converter being capable of receiving the current signal on a first conductive line and converting the current signal into a voltage signal, the converter comprising a first resistive device coupled between the first conductive line and a reference voltage line, and a first capacitive device coupled in parallel with the first resistive device between the first conductive line and the reference voltage line.

Claims

1. A photo detector device configured for use with a display device, the photo detector device comprising:

a photosensitive transistor formed on a substrate of the display device, the photosensitive transistor being capable of detecting an optical signal and converting the optical signal into a current signal;

a converter formed on the substrate of the display device, the converter being capable of receiving the current signal on a first conductive line and converting the current signal into a voltage signal, the voltage signal being used to determine the position of an optical source, the converter comprising;

a first resistive device coupled between the first conductive line and a reference voltage line, wherein the first resistive device includes a first transistor, the first transistor including a gate coupled to the first conductive line, a drain coupled to the first conductive line, and a source coupled to the reference voltage line; and

a first capacitive device coupled in parallel with the first resistive device between the first conductive line and the reference voltage line.

2. The device of claim 1, wherein the photosensitive transistor includes a gate coupled to a second conductive line, and a source coupled to the first conductive line, the first conductive line and the second conductive line being orthogonal to one another.

3. The device of claim 1 further comprising a switching transistor capable of driving the photosensitive transistor.

4. The device of claim 3, wherein the switching transistor includes a gate connected with a gate of a switching transistor of the display device.

5. The device of claim 3, wherein the switching transistor includes a gate coupled to a second conductive line and a source coupled to the first conductive line, the first conductive line and the second conductive line, the first conductive line and the second conductive line being orthogonal to one another.

6. The device of claim 5, wherein the photosensitive transistor includes a gate coupled to a voltage source, a drain coupled to the voltage source, and a source coupled to a drain of the switching transistor.

7. The device of claim 3, wherein the switching transistor includes a gate coupled to a second conductive line and a drain coupled to a voltage source, the second conductive line and the first conductive line being orthogonal to one another.

8. The device of claim 7, wherein the photosensitive transistor includes a gate coupled to a source of the switching transistor, and a source coupled to the first conductive line.

9. The device of claim 1, wherein the first resistive device includes a first metal region electrically coupled to the first conductive line, a second metal region electrically coupled to the reference voltage line, and a first amorphous silicon region defined between the first metal region and the second metal region.

10. The device of claim 1, wherein the converter further comprises a second resistive device, the second resistive device including a third metal region electrically coupled to the source of the transistor, a fourth metal region electrically coupled to the reference voltage line, and a second amorphous silicon region defined between the third metal region and the fourth metal region.

11. The device of claim 1, wherein the converter further comprises a second transistor, the second transistor including a gate coupled to the first conductive line, and a source coupled to a circuit that determines the position of the optical source.

12. The device of claim 11, wherein the converter further comprises a third transistor, the third transistor including a gate coupled to the source of the second transistor, a drain coupled to the source of the second transistor, and a source coupled to the reference voltage line.

13. A photo detector device configured for use with a display device, the photo detector device comprising:

a plurality of first conductive lines extending in parallel with each other;

a plurality of second conductive lines extending in parallel with each other and being orthogonal to the plurality of first conductive lines;

an array of photosensitive transistors formed on a substrate of the display device, each of the photosensitive transistors being disposed near one of the plurality of first conductive lines and one of the plurality of the second conductive lines and being capable of detecting an optical signal and converting the optical signal into a current signal;

an array of converters formed on the substrate of the display device, each of the converters being capable of receiving the current signal on one of the first conductive lines, converting the current signal into a voltage signal, the voltage signal being used to determine the position of an optical source, and comprising;

a first resistive device coupled between the first conductive line and a reference voltage line, wherein the first resistive device includes a first transistor, the first transistor including a gate coupled to the first conductive line, a drain coupled to the first conductive line, and a source coupled to the reference voltage line; and

a first capacitive device coupled in parallel with the first resistive device between the first conductive line and the reference voltage line.

14. The device of claim 13, further comprising a circuit including a multiplexer capable of selecting a voltage signal from one of the converters.

15. The device of claim 14, wherein the circuit includes an amplifier circuit capable of amplifying a voltage signal from the multiplexer, and an analog-to-digital converter for converting the voltage signal into a digital signal.

16. The device of claim 15, wherein the circuit includes a processor capable of calculating the coordinates of an optical source based on the digital signal.

17. The device of claim 13, wherein the first resistive device includes a first metal region electrically coupled to the first conductive line, a second metal region electrically coupled to the reference voltage line, and a first amorphous silicon region defined between the first metal region and the second metal region.

18. The device of claim 17, wherein each of the converters further comprises a transistor, the transistor including a gate coupled to the first conductive line, and a source coupled to a circuit that determines the position of the optical source.

19. The device of claim 18, wherein each of the converters further comprises a second resistive device, the second resistive device including a third metal region electrically coupled to the source of the transistor, a fourth metal region electrically coupled to the reference voltage line, and a second amorphous silicon region defined between the third metal region and the fourth metal region.

20. The device of claim 13, wherein each of the converters further comprises a second transistor, the second transistor including a gate coupled to the first conductive line, a drain coupled to the first conductive line, and a source coupled to the circuit.

21. The device of claim 20, wherein each of the converters further comprises a third transistor, the third transistor including a gate coupled to the source of the second transistor, a drain coupled to the source of the second transistor, and a source coupled to the reference voltage line.

22. A photo detector device configured for use with a display device, the photo detector device comprising:

a photosensitive transistor formed on a substrate of the display device, the photosensitive transistor being capable of detecting an optical signal and converting the optical signal into a current signal;

a switching transistor formed on the substrate of the display device, the switching transistor being capable of driving the photosensitive transistor and being disposed near an intersection of a first conductive line and a second conductive line, the first conductive line and the second conductive line being orthogonal to one another; and

a converter formed on the substrate of the display device, the converter being capable of receiving the current signal on the first conductive line and converting the current signal into a voltage signal, the voltage signal being used to determine the position of an optical source, the converter comprising;

a first resistive device coupled between the first conductive line and a reference voltage line, wherein the first resistive device includes a first transistor, the first transistor including a gate coupled to the first conductive line, a drain coupled to the first conductive line, and a source coupled to the reference voltage line; and

a first capacitive device coupled in parallel with the first resistive device between the first conductive line and the reference voltage line.

23. The device of claim 22, wherein the switching transistor includes a gate connected with a gate of a switching transistor of the display device.

24. The device of claim 22, wherein the switching transistor includes a gate coupled to the second conductive line and a source coupled to the first conductive line.

25. The device of claim 24, wherein the photosensitive transistor includes a gate coupled to a voltage source, a drain coupled to the voltage source, and a source coupled to a drain of the switching transistor.

26. The device of claim 22, wherein the switching transistor includes a gate coupled to the second conductive line and a drain coupled to a voltage source.

27. The device of claim 26, wherein the photosensitive transistor includes a gate coupled to a source of the switching transistor, a drain coupled to the source of the switching transistor, and a source coupled to the first conductive line.