Optical sensor device, display apparatus, and method for driving optical sensor device

• US 8,368,677 B2
• Filed: 03/30/2011
• Issued: 02/05/2013
• Est. Priority Date: 03/31/2010
• Status: Active Grant

• Current Assignee: Solas OLED Limited (Atlantic IP Services Limited)
• Original Assignee: Casio Computer Company Limited
• Inventors: Yamamoto, Takumi
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Sadio, Insa
• Application Number:
  US13/075,203
• Publication Number:
  US 20110242075A1
• Time in Patent Office: 678 Days
• Field of Search: 345/156, 345/157, 345/163, 345/166, 345/175, 345/204, 345/207, 345/690, 345/697, 178/18.01, 178/18.03, 178/18.09
• US Class Current: 345/207
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An optical sensor device includes a plurality of optical sensor units two-dimensionally arranged, a scan driver, and a detection driver. The scan driver sets optical sensor units, in each row, in a selected state. The detection driver acquires detection signals corresponding to illuminance of incident light on the optical sensor units. Each of the optical sensor units comprises a first optical sensor including a first photoelectric conversion section blocked from light and a second optical sensor including a second photoelectric conversion section configured to change the illuminance in response to an externally applied external force. The detection driver maintains each voltage of electrodes of the first optical sensors and each voltage of electrodes of the second optical sensors in equal voltage levels to each other, and acquires a plurality of voltage signals in parallel.

Claims

1. An optical sensor device comprising:

a first substrate;

a plurality of optical sensor units two-dimensionally arranged on a surface of the first substrate;

a scan driver which sets the optical sensor units disposed in each row in a selected state; and

a detection driver which acquires detection signals corresponding to illuminance of incident light on the optical sensor units set in the selected state, wherein each of the optical sensor units comprises a first optical sensor including a first photoelectric conversion section blocked from light and a second optical sensor including a second photoelectric conversion section configured to change the illuminance in response to an externally applied external force, and the detection driver maintains each voltages of electrodes of the first optical sensors and each voltages of electrodes of the second optical sensors, which are set in the selected state, in equal voltage levels to each other, and acquires a plurality of voltage signals in parallel as the detection signals, wherein each of the voltage signals corresponds to current flowing in accordance with the illuminance on each of the second optical sensors set in the selected state.

2. The optical sensor device according to claim 1, further comprising:

a second substrate comprising a surface located opposite to the surface of the first substrate and being provided at a predetermined distance from the surface of the first substrate;

light blocking walls provided on the surface of the first substrate and the surface of the second substrate at positions surrounding the second semiconductor layer and configured to block visible light; and

a gap formed between an upper end of the light blocking walls and the surface of the first substrate and the surface of the second substrate,

wherein the gap forms an optical valve configured to narrow to block light to the second photoelectric conversion section of the second thin-film-transistor optical sensors when the external force is applied to the first substrate or the second substrate.

3. The optical sensor device according to claim 1, wherein

the first optical sensors and the second optical sensors are made by thin-film-transistors, and

the first photoelectric conversion section and the second photoelectric conversion section include semiconductor layers.

4. The optical sensor device according to claim 3, further comprising:

a plurality of sensor-gate-lines which are disposed in the row direction and connected in common to gate electrodes of the first optical sensors and the second optical sensors which are disposed in the row direction;

a plurality of first-sensor-first-signal-lines which are disposed in the column direction and connected to one of drain electrodes and source electrodes of the first optical sensors which are disposed in the column direction;

a plurality of first-sensor-second-signal-lines which are disposed in the column direction and connected to the other one of the drain electrodes and the source electrodes of the first optical sensors which are disposed in the column direction;

a plurality of second-sensor-first-signal-lines which are disposed in the column direction and connected to one of drain electrodes and source electrodes of the second optical sensors which are disposed in the column direction; and

a plurality of second-sensor-second-signal-lines which are disposed in the column direction and connected to the other one of the drain electrodes and the source electrodes of the second optical sensors which are disposed in the column direction;

wherein the scan driver outputs, to each of the sensor-gate-lines, a sensor scan signal having a signal level at which the first optical sensors and the second optical sensors are turned on.

5. The optical sensor device according to claim 4, wherein

the plurality of optical sensor units are divided in a plurality of optical sensor groups which are two-dimensionally arranged,

each of the plurality of optical sensor groups include predetermined number of the optical sensor units disposed in predetermined number of rows and predetermined number of columns,

a predetermined number of the sensor gate lines which are connected to each of the optical sensor groups arranged in a row direction, are connected to a common-sensor-gate-line in common and connected to the scan driver through the common-sensor-gate-line,

a predetermined number of the first-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-first-sensor-first-signal-line in common and connected to the detection driver through the common-first-sensor-first-signal-line,

a predetermined number of the second-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-sensor-first-signal-line in common and connected to the detection driver through the common-second-sensor-first-signal-line,

a predetermined number of the first-sensor-second-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-first-sensor-second-signal-line in common and connected to the detection driver through the common-first-sensor-second-signal-line,

a predetermined number of the second-sensor-second-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-sensor-second-signal-line in common and connected to the detection driver through the common-second-sensor-second-signal-line.

6. The optical sensor device according to claim 4, wherein

the plurality of optical sensor units are divided in a plurality of optical sensor groups which are two-dimensionally arranged,

each of the plurality of optical sensor groups include predetermined number of the optical sensor units disposed in predetermined number of rows and predetermined number of columns,

a predetermined number of the sensor gate lines which are connected to each of the optical sensor groups arranged in a row direction, are connected to a common-sensor-gate-line in common and connected to the scan driver by the common-sensor-gate-line,

a predetermined number of the first-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-first-sensor-first-signal-line in common and connected to the detection driver by the common-first-sensor-first-signal-line,

a predetermined number of the second-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-sensor-first-signal-line in common and connected to the detection driver by the common-second-sensor-first-signal-line,

a predetermined number of the first-sensor-second-signal-lines and a predetermined number of the second-sensor-second-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-signal-line in common and connected to the detection driver by the common-second-signal-line.

7. The optical sensor device according to claim 4, further comprising:

a plurality of display pixels which are two-dimensionally arranged on the surface of the first substrate and each have an optical element;

a plurality of scan lines which are disposed in the row direction and connected to the display pixels which are disposed in the row direction; and

a plurality of signal lines which are disposed in the column direction and connected to the display pixels which are disposed in the column direction,

wherein the display pixels comprise a predetermined number of subpixels in different colors disposed in the row direction, and

the first optical sensors and the second optical sensors are each provided in an area between the display pixels disposed in the row direction.

8. The optical sensor device according to claim 3, further comprising:

a plurality of current sources which are connected to each of the first-sensor-first-signal-lines and supply a current to each of the first-sensor-first-signal-lines;

a plurality of buffer circuits which are provided between each of the second-sensor-first-signal-lines and each of the first-sensor-first-signal-lines adjacent to one another and a input terminal of the buffer circuit is connected to each of the second-sensor-first-signal-lines and an output terminal of the buffer circuit is connected to each of the first-sensor-first-signal-lines;

a voltage source which is connected to each of the first-sensor-second-signal-lines and supply a voltage to the each of the first-sensor-second-signal-lines;

a plurality of current-to-voltage conversion circuits which are connected to each of the first-sensor-second-signal-lines and each of the second-sensor-second-signal-lines adjacent to one another and convert a current flowing through each of the second-sensor-second-signal-line into a plurality of voltage signals; and

a parallel-to-serial conversion circuit which supplied the plurality of voltage signals in a form of parallel signals from the plurality of current-to-voltage conversion circuits and convert the parallel signals into a serial signal.

9. The optical sensor device according to claim 3, wherein the detection driver comprises:

a plurality of current sources which are connected in common to each of the first-sensor-first-signal-lines and each of the second-sensor-first-signal-lines adjacent to each other and supply a current to each of the first-sensor-first-signal-lines and each of the second-sensor-first-signal-lines;

a voltage source which is connected to each of the first sensor second signal lines and supply a voltage to each of the first sensor second signal lines;

a plurality of current-to-voltage conversion circuits which are connected to each of the first-sensor-second-signal-lines and each of the second-sensor-second-signal-lines adjacent to one another and convert a current flowing through each of the second-sensor-second-signal-line into a plurality of voltage signals; and

a parallel-to-serial conversion circuit which supplied the plurality of voltage signals in a form of parallel signals from the plurality of current-to-voltage conversion circuits and convert the parallel signals into a serial signal.

10. The display apparatus according to claim 9, further comprising:

a plurality of sensor-gate-lines which are disposed in the row direction and connected in common to gate electrodes of the first optical sensors and the second optical sensors which are disposed in the row direction;

a plurality of first-sensor-first-signal-lines which are disposed in the column direction and connected to one of drain electrodes and source electrodes of the first optical sensors which are disposed in the column direction;

a plurality of first-sensor-second-signal-lines which are disposed in the column direction and connected to the other one of the drain electrodes and the source electrodes of the first optical sensors which are disposed in the column direction;

a plurality of second-sensor-first-signal-lines which are disposed in the column direction and connected to one of drain electrodes and source electrodes of the second optical sensors which are disposed in the column direction; and

a plurality of second-sensor-second-signal-lines which are disposed in the column direction and connected to the other one of the drain electrodes and the source electrodes of the second optical sensors which are disposed in the column direction;

wherein the scan driver outputs, to each of the sensor-gate-lines, a sensor scan signal having a signal level at which the first optical sensors and the second optical sensors are turned on.

11. A display apparatus comprising:

a substrate;

a plurality of display pixels two-dimensionally arranged on a surface of the substrate;

a plurality of optical sensor units two-dimensionally arranged on the surface of the substrate, each of the display pixels comprising an optical element;

a scan driver which sets the optical sensor units disposed in each row in a selected state; and

a detection driver which acquires detection signals corresponding to illuminance of incident light on the optical sensor units set in the selected state, wherein each of the optical sensors comprise units a first optical sensor including a first photoelectric conversion section blocked from light and a second optical sensor including a second photoelectric conversion section configured to change the illuminance in response to an externally applied external force, and the detection driver maintains each voltages of electrodes of the first optical sensors and each voltages of electrodes of the second optical sensors, which are set in the selected state, in equal voltage levels to each other, and acquires a plurality of voltage signals in parallel as the detection signals, wherein each of the voltage signals corresponds to current flowing in accordance with the illuminance on the second optical sensor set in the selected state.

12. The display apparatus according to claim 11, wherein

the first optical sensors and the second optical sensors are made by thin-film-transistors,

the first photoelectric conversion section and the second photoelectric conversion section include semiconductor layers.

13. The display apparatus according to claim 12, wherein

the plurality of optical sensor units are divided in a plurality of optical sensor groups which are two-dimensionally arranged,

each of the plurality of optical sensor groups include predetermined number of the optical sensor units disposed in predetermined number of rows and predetermined number of columns,

a predetermined number of the sensor gate lines which are connected to each of the optical sensor groups arranged in a row direction, are connected to a common-sensor-gate-line in common and connected to the scan driver by the common-sensor-gate-line,

a predetermined number of the first-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-first-sensor-first-signal-line in common and connected to the detection driver by the common-first-sensor-first-signal-line,

a predetermined number of the second-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-sensor-first-signal-line in common and connected to the detection driver by the common-second-sensor-first-signal-line,

a predetermined number of the first-sensor-second-signal-lines and a predetermined number of the second-sensor-second-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-signal-line in common and connected to the detection driver by the common-second-signal-line.

14. The display apparatus according to claim 11, wherein

the plurality of optical sensor units are divided in a plurality of optical sensor groups which are two-dimensionally arranged,

each of the plurality of optical sensor groups include predetermined number of the optical sensor units disposed in predetermined number of rows and predetermined number of columns,

a predetermined number of the sensor gate lines which are connected to each of the optical sensor groups arranged in a row direction, are connected to a common-sensor-gate-line in common and connected to the scan driver through the common-sensor-gate-line,

a predetermined number of the first-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-first-sensor-first-signal-line in common and connected to the detection driver through the common-first-sensor-first-signal-line,

a predetermined number of the second-sensor-first-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-sensor-first-signal-line in common and connected to the detection driver through the common-second-sensor-first-signal-line,

a predetermined number of the first-sensor-second-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-first-sensor-second-signal-line in common and connected to the detection driver through the common-first-sensor-second-signal-line,

a predetermined number of the second-sensor-second-signal-lines connected to each of the optical sensor groups arranged in a column direction are connected to a common-second-sensor-second-signal-line in common and connected to the detection driver through the common-second-sensor-second-signal-line.

15. The display apparatus according to claim 11, wherein each of the display pixels comprises a liquid crystal display pixel as the optical element.

16. The display apparatus according to claim 11, wherein each of the display pixels comprises an organic electroluminescence element as the optical element.

17. a display apparatus comprising:

a substrate;

a plurality of display pixels which are two-dimensionally arranged on the surface of the substrate and each have an optical element; and

a plurality of optical sensor units two-dimensionally arranged on the surface of the substrate, each of the display pixels comprising an optical element a scan driver which sets the optical sensor units disposed in each row in a selected state;

a detection driver which acquires detection signals corresponding to illuminance of incident light un the optical sensor units set in the selected state, wherein each of the optical sensor units comprises a first optical sensor including a first photoelectric conversion section blocked from light and a second optical sensor including a second photoelectric conversion section configured to chance the illuminance in response to an externally applied external force, the display pixels comprise a predetermined number of subpixels in different colors disposed in the row direction, the first optical sensors and the second optical sensors are each provided in an area between the display pixels disposed in the row direction; and

the detection driver maintains each voltages of electrodes of the first optical sensors and each voltages of electrodes of the second optical sensor, which are set in the selected state in equal voltage levels to each other, and acquires a plurality of voltage signals in parallel as the detection signals, wherein each of the voltage signals corresponds to current flowing in accordance with the illuminance on each of the second optical sensors set in the selected state.

18. The display apparatus according to claim 17, wherein

the first optical sensors and the second optical sensors are made by thin-film-transistors,

the first photoelectric conversion section and the second photoelectric conversion section include semiconductor layers.

19. The display apparatus according to claim 18, further comprising:

a plurality of scan lines which are disposed in the row direction and connected to the display pixels which are disposed in the row direction;

a plurality of signal lines which are disposed in the column direction and connected to the display pixels which are disposed in the column direction;

a plurality of sensor-gate-lines which are disposed in the row direction and connected in common to gate electrodes of the first optical sensors and the second optical sensors which are disposed in the row direction;

a plurality of first-sensor-first-signal-lines which are disposed in the column direction and connected to one of drain electrodes and source electrodes of the first optical sensors which are disposed in the column direction;

a plurality of first-sensor-second-signal-lines which are disposed in the column direction and connected to the other one of the drain electrodes and the source electrodes of the first optical sensors which are disposed in the column direction;

a plurality of second-sensor-first-signal-lines which are disposed in the column direction and connected to one of drain electrodes and source electrodes of the second optical sensors which are disposed in the column direction; and

a plurality of second-sensor-second-signal-lines which are disposed in the column direction and connected to the other one of the drain electrodes and the source electrodes of the second optical sensors which are disposed in the column direction.

20. The display apparatus according to claim 19, further comprising a plurality of first display pixel groups two-dimensionally arranged,

each of the first display pixel groups include an even number of the display pixels disposed adjacent to one another in the column direction,

the first optical sensors and the second optical sensors are alternately disposed along the row direction in areas between the first display pixel groups arranged adjacent to each other in the row direction,

the sensor-gate-lines are provided in areas between half number of the display pixels of the first display pixel group, and

the scan lines are provided in areas between each of the first display pixel groups in the column direction.

21. The display apparatus according to claim 20, wherein length of the first and second optical sensors in the column direction are equal to or smaller than length of the first display pixel group in the column direction.

22. The optical sensor device according to claim 19, further comprising a plurality of second display pixel groups two-dimensionally arranged,

each of the second display pixel groups include an even number of the display pixels disposed adjacent to one another in the row direction,

the first optical sensors and the second optical sensors are alternately provided along the row direction in areas between half number of the display pixels of the second display pixel group,

the first-sensor-first-signal-lines, the first sensor-second-signal-lines, the second-sensor-first-signal-lines, and the second-sensor-second-signal-lines are provided in areas between half number of the display pixels of the second display pixel group, and

the signal lines are provided in areas except the areas between half number of the display pixels of the second display pixel group.

23. The display apparatus according to claim 22, wherein length of the first and second optical sensors in the column direction are equal to or smaller than length of the display pixel in the column direction.

24. The optical sensor device according to claim 19, further comprising a plurality of third display pixel groups two-dimensionally arranged,

each of the third display pixel groups include an even number of the display pixels disposed in each of the column direction and the row direction,

the first optical sensors and the second optical sensors are alternately provided along the row direction in areas between half number of the display pixels of the third display pixel group in the row direction,

the sensor-gate-lines are provided in areas between half number of the display pixels of the third display pixel group in the column direction,

the first-sensor-first-signal-lines, the first sensor-second-signal-lines, the second-sensor-first-signal-lines, and the second-sensor-second-signal-lines are provided in areas between half number of the display pixels of the third display pixel group in the row direction,

the scan lines are provided in areas between each of the third display pixel groups in the column direction, and

the signal lines are provided in areas except the areas between half number of the display pixels of the third display pixel group in the row direction.

25. The display apparatus according to claim 24, wherein length of the first and second optical sensors in the column direction are equal to or smaller than the third display pixel group in the column direction.

26. A method for driving an optical sensor device comprising a plurality of optical sensor units two-dimensionally arranged, each of the optical sensor units comprising a first optical sensor including a first semiconductor layer blocked from light and a second optical sensor including a second semiconductor layer configured to change an illuminance of incident light in response to an externally applied external force, the method comprising:

setting the first optical sensors and the second optical sensors disposed in each of the rows in a selected state; and

maintaining each voltages of electrodes of the first optical sensors and second optical sensors and each voltages of electrodes of the second optical sensors, which are set in the selected state, in equal voltage levels to each other, and then acquiring a plurality of voltage signals in parallel, the voltage signals corresponding to currents flowing in accordance with the illuminance on the second optical sensors.

27. The method for driving an optical sensor device according to claim 26, further comprising acquiring the plurality of voltage signals as parallel signals, and converting the parallel signals into a serial signal, and outputting the serial signal.

28. The method for driving an optical sensor device according to claim 26, wherein the first optical sensors and the second optical sensors are made by thin-film-transistors, the acquiring comprises:

supplying a current to one of the drain electrode and source electrode of each of the first optical sensors;

outputting a floating voltage of the one of the drain electrode and source electrode of each of the first optical sensors set in the selected state which the floating voltage is generated by a current flowing between the drain electrode and source electrode of each of the first optical sensors, to one of the drain electrode and source electrode of each of the corresponding second optical sensors via a buffer circuit;

applying a voltage to the other of the drain electrode and source electrode of each of the first optical sensors;

subjecting the other of the drain electrode and source electrode of each of the first optical sensors set in the selected state and the other of the drain electrode and source electrode of each of the second optical sensors to imaginary short-circuiting by a operational amplifier and to set them in an equal voltage level; and

converting a current flowing between the drain electrode and source electrode of each of the second optical sensor into the voltage signal.

29. The method for driving an optical sensor device according to claim 26, wherein the first optical sensors and the second optical sensors are made by thin-film-transistors, the acquiring comprises:

connecting one of the drain electrode and source electrode of each of the first optical sensors to one of the drain electrode and source electrode of each of the corresponding second optical sensors to a connection point and supplying a current to the connection point;

applying a voltage to the other of the drain electrode and source electrode of each of the first optical sensors;

subjecting the other of the drain electrode and source electrode of each of the first optical sensors set in the selected state and the other of the drain electrode and source electrode of each of the second optical sensors to imaginary short-circuiting by a operational amplifier and to set them in an equal voltage level; and

converting a current flowing between the drain electrode and source electrode of each of the second optical sensor into the voltage signal.