SENSING CIRCUIT, METHOD OF DRIVING SENSING CIRCUIT, DISPLAY DEVICE, METHOD OF DRIVING DISPLAY DEVICE, AND ELECTRONIC APPARATUS

• US 20090273580A1
• Filed: 04/21/2009
• Published: 11/05/2009
• Est. Priority Date: 05/02/2008
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: OTA, Hitoshi, KANDA, Eiji
• Granted Patent: US 8,319,750 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• 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: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A display device includes: a first substrate and a second substrate that face each other; electro-optical elements that are interposed between the first substrate and the second substrate; light detecting units that are provided between the first substrate and the second substrate and output first detection signals having levels corresponding to the amount of incident light; and capacitance detecting units that include capacitive elements each having a first electrode and a second electrode provided between the first substrate and the second substrate, output second detection signals having levels corresponding to the capacitance values of the capacitive elements, and are provided separately from the light detecting units.

Claims

1. A display device comprising:

a first substrate and a second substrate that face each other;

electro-optical elements that are interposed between the first substrate and the second substrate;

light detecting units that are provided between the first substrate and the second substrate and output first detection signals having levels corresponding to the amount of incident light; and

capacitance detecting units that include capacitive elements each having a first electrode and a second electrode provided between the first substrate and the second substrate, output second detection signals having levels corresponding to the capacitance values of the capacitive elements, and are provided separately from the light detecting units.

2. The display device according to claim 1,

wherein each of the capacitive elements includes the first electrode provided on a surface of the first substrate facing the second substrate, the second electrode provided on a surface of the second substrate facing the first substrate, and an electro-optical material interposed between the first electrode and the second electrode, and

each of the second electrodes is provided on the surface of the second substrate facing the first substrate so as to cover a first protruding portion that protrudes toward the first substrate.

3. The display device according to claim 1,

wherein the first electrodes and the second electrodes are provided on the first substrate,

each of the capacitive elements includes the first electrode, the second electrode, and an electro-optical material provided between the first and second electrodes and the second substrate, and

first protruding portions that protrude toward the first substrate are provided on a surface of the second substrate facing the first substrate such that each of the first protruding portions faces at least a portion of the first electrode and the second electrode.

4. The display device according to claim 2, further comprising:

spacers each of which includes a second protruding portion that is provided at a different position from the light detecting unit and the capacitance detecting unit on the surface of the first substrate facing the second substrate and protrudes toward the second substrate and a third protruding portion that is provided at a position facing the second protruding portion on the surface of the second substrate facing the first substrate and protrudes toward the first substrate,

wherein the second protruding portion and the third protruding portion come into contact with each other to form the spacer, and

the first protruding portion and the third protruding portion have the same height.

5. The display device according to claim 4,

wherein the light detecting unit includes a light detecting element that is provided on the surface of the first substrate facing the second substrate, and

the second protruding portion includes a second light detecting element having the same structure as the light detecting element.

6. The display device according to claim 2, further comprising:

second spacers,

wherein the light detecting unit includes a light detecting element that is provided on the surface of the first substrate facing the second substrate,

each of the second spacers includes the light detecting element and a fourth protruding portion that is provided at a position facing the light detecting element on the surface of the second substrate facing the first substrate so as to protrude toward the first substrate,

the light detecting element and the fourth protruding portion come into contact with each other to form the second spacer, and

the fourth protruding portion and the first protruding portion have the same height.

7. The display device according to claim 6,

wherein the fourth protruding portion is made of a translucent material.

8. The display device according to claim 1, further comprising:

a detecting circuit that detects contact between an object and the display device on the basis of the first detection signal and the second detection signal.

14. An electronic apparatus comprising the display device according to claim 1.

9. A sensing circuit comprising:

a first substrate and a second substrate that face each other;

a dielectric material that is interposed between the first substrate and the second substrate;

a plurality of scanning lines that extend along the first substrate or the second substrate between the first substrate and the second substrate; and

a plurality of capacitance sensing circuits and a plurality of light sensing circuits that are arranged in a matrix along the first substrate or the second substrate between the first substrate and the second substrate,

wherein the light sensing circuits are connected to the scanning lines to which the plurality of capacitance sensing circuits are not connected, and output light measurement signals having levels corresponding to the amount of incident light, and

the capacitance sensing circuits are connected to the scanning lines to which the plurality of light sensing circuits are not connected, include capacitive elements each having the dielectric material, a first electrode, and a second electrode, and output capacitance measurement signals having levels corresponding to the capacitance values of the capacitive elements.

10. The sensing circuit according to claim 9, further comprising:

a plurality of sensing lines that extend along the first substrate or the second substrate between the first substrate and the second substrate,

wherein the capacitance sensing circuits and the light sensing circuits are connected to the sensing lines.

11. The sensing circuit according to claim 9,

wherein the number of light sensing circuits is larger than that of capacitance sensing circuits.

12. The sensing circuit according to claim 9, further comprising:

a shift register for light to which the scanning lines connected to the plurality of light sensing circuits are connected; and

a shift register for capacitance to which the scanning lines connected to the plurality of capacitance sensing circuits are connected,

wherein the number of stages of the shift register for capacitance is smaller than that of the shift register for light.

13. A display device comprising:

the sensing circuit according to claim 9; and

a plurality of pixel circuits that are arranged in a matrix along the first substrate or the second substrate between the first substrate and the second substrate,

wherein each of the pixel circuits includes the dielectric material, and

the dielectric material is liquid crystal.

15. A method of driving the sensing circuit according to claim 9, comprising:

driving the plurality of capacitance sensing circuits;

driving the plurality of light sensing circuits; and

alternately performing the driving of the capacitance sensing circuits and the driving of the light sensing circuits.

16. A method of driving the display device according to claim 13, comprising:

driving the plurality of pixel circuits and the plurality of capacitance sensing circuits;

driving the plurality of pixel circuits and the plurality of light sensing circuits; and

alternately performing the driving of the pixel circuits and the capacitance sensing circuits and the driving of the pixel circuits and the light sensing circuits.

17. An electronic apparatus comprising the sensing circuit according to claim 9.