DISPLAY DEVICE

• US 20120044176A1
• Filed: 08/10/2011
• Published: 02/23/2012
• Est. Priority Date: 08/19/2010
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Toshiba Mobile Display Company Limited (Japan Display Incorporated)
• Inventors: Nakamura, Takashi, Tomita, Satoru, Fuchi, Masayoshi, Hayashi, Hirotaka, Ishikawa, Miyuki, Tada, Masahiro, Takahashi, Hideyuki, Imai, Takayuki, Okada, Takashi, Endo, Takahiko, Saruhashi, Yasuo, Saito, Keiichi
• Granted Patent: US 9,176,616 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

In one embodiment, a display device having a touch function includes an insulating substrate and a plurality of pixels formed on the insulating substrate and arranged in a matrix of rows and columns. The pixels form a plurality of pixel blocks formed of a plurality of rows and columns of the pixels. A sensor circuit is arranged in a space between adjacent pixels on the insulating substrate and includes a coupling electrode, a detection electrode arranged adjacent to the coupling electrode for forming a coupling capacitance therebetween, and a reading-out circuit to read out a potential of the detection electrode. At least one sensor circuit is arranged in each pixel block. The contact or non-contact by a fingertip or a nib is detected by a potential difference of the detection electrode.

Claims

1. A display device, comprising:

an insulating substrate;

a plurality of pixels formed on the insulating substrate and arranged in a matrix of rows and columns, the pixels forming a plurality of pixel blocks formed of a plurality of rows and columns of the pixels;

a sensor circuit arranged in a space between adjacent pixels on the insulating substrate and including a coupling electrode, a detection electrode arranged adjacent to the coupling electrode for forming a coupling capacitance therebetween, and a reading-out circuit to read out a potential of the detection electrode, wherein at least one sensor circuit is arranged in each pixel block;

a plurality of scanning lines extending along the pixels arranged in the row direction;

a plurality of signal lines extending along the pixels arranged in the column direction; and

a driver circuit for writing an image signal into the respective pixels through the signal lines by driving the scanning lines in a period to drive the pixels, wherein the signal lines are used as a precharge line to supply a precharge voltage to the detection electrode and a reading-out line to read out the potential of the detection electrode in a driving period for driving the sensor circuit.

2. The display device according to claim 1, wherein the sensor circuit includes an amplification circuit to read out the potential of the detection electrode.

3. The display device according to claim 2, wherein the sensor circuit further includes a read switch to read out the potential of the detection electrode.

4. The display device according to claim 1, wherein the driver circuit further includes a circuit device to supply a precharge voltage to the reading-out line.

5. The display device according to claim 1, wherein the driver circuit further includes a signal line driver, a scanning line driver, and a TCON (Timing Controller).

6. The display device according to claim 1, wherein the display device comprises a circuit substrate connected to the insulating substrate of the display device and provided with a TCON, a microcomputer, a memory, an A/D converter, and a comparison circuit.

7. The display device according to claim 6, wherein the output signal of the sensor circuit is compared with a reference voltage by the comparison circuit, then converted into digital signals by the A/D converter, and transmitted to the microcomputer to calculate a coordinate of a contacted position by a finger or a nib.

8. The display device according to claim 1, wherein the period to drive the sensor circuit is a period of a horizontal blanking period.

9. The display device according to claim 1, wherein the period to drive the sensor circuit is a period of a vertical blanking period.

10. The display device according to claim 1, wherein the driver circuit drives the sensor circuit after the writing operation of the image signal completes in each period of ½

vertical periods, and the sensor circuits arranged in even rows and the sensor circuits arranged in odd rows are alternately driven in every ½

vertical periods.

11. The display device according to claim 1, further comprising a counter substrate arranged opposing the insulating substrate, wherein the counter substrate is arranged opposing the pixels and includes an electric conductive layer formed on the counter substrate.

12. The display device according to claim 11, wherein the resistivity of the electric conductive layer is equal to or more than 1.0×

10⁹ (Ω

/m²).

13. The display device according to claim 2, further comprising a time detection device to detect for the output signal of the sensor circuit to reach to a reference voltage.

14. The display device according to claim 13, further comprising an adjustment device to adjust the time for the output signal of the sensor circuit to reach to the reference voltage by adjusting the precharge voltage.

15. The display device according to claim 1, further comprising a coupling line to change a potential of the coupling electrode, wherein a potential change of the detection electrode is read out by driving the coupling line.

16. The display device according to claim 15, wherein the coupling line is arranged in parallel to the scanning lines.

17. The display device according to claim 1, wherein the display device is formed of a liquid crystal display device or an organic electroluminescence display device.

18. A display device, comprising:

an insulating substrate;

a plurality of pixels formed on the insulating substrate and arranged in a matrix of rows and columns, the pixels forming a plurality of pixel blocks formed of a plurality of rows and columns of the pixels;

a sensor circuit arranged in a space between adjacent pixels on the insulating substrate and including a coupling electrode, a detection electrode arranged adjacent to the coupling electrode for forming a coupling capacitance therebetween, and a reading-out circuit to read out a potential of the detection electrode, wherein at least one sensor circuit is arranged in each pixel block;

a plurality of scanning lines extending along the pixels arranged in the row direction;

a plurality of signal lines extending along the pixels arranged in the column direction;

a driver circuit for writing an image signal into the respective pixels through the signal lines by driving the scanning lines in a period to drive the pixels, wherein the signal lines are used as a precharge line to supply a precharge voltage to the detection electrode and a reading-out line to read out the potential of the detection electrode in a driving period for driving the sensor circuit;

a coupling line to change a potential of the coupling electrode, wherein a potential change of the detection electrode is read out by driving the coupling line; and

a peripheral circuit including a TCON, a microcomputer, a memory, an A/D converter, and a comparison circuit to compare an output signal of the sensor circuit with a reference voltage.

19. The display device according to claim 18, wherein the sensor circuit includes an amplification circuit to read out the potential of the detection electrode.

20. The display device according to claim 18, wherein the display device is formed of a liquid crystal display device or an organic electroluminescence display device.