DISPLAY DEVICE, DISPLAY MODULE, AND ELECTRONIC DEVICE

• US 20160232834A1
• Filed: 10/28/2015
• Published: 08/11/2016
• Est. Priority Date: 10/31/2014
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KIMURA, Hajime, MIYAKE, Hiroyuki
• Granted Patent: US 10,002,564 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/043 Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/046 Dealing with screen burn-in prevention or compensation of the effects thereof
• CPC Class Codes: G09G 2330/045 Protection against panel overheating
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/325 the data current flowing through the driving transistor during a setting phase, e.g. by using a switch for connecting the driving transistor to the data driver

Abstract

To provide a display device which can perform external correction and has a reduced area occupied by a read circuit. The display device includes a pixel and the read circuit. The pixel includes a transistor and a display element. The read circuit includes a function selection portion and an operational amplifier. The transistor is electrically connected to the function selection portion through a wiring. The operational amplifier is electrically connected to the function selection portion. The function selection portion includes at least one switch and can select the function of the read circuit by switching of the switch.

Claims

1. A display device comprising:

a pixel comprising a transistor and a display element;

a first circuit comprising a second circuit and an operational amplifier, the second circuit comprising a switch; and

a wiring,

wherein the transistor is electrically connected to the switch of the second circuit through the wiring,

wherein the operational amplifier is electrically connected to the switch of the second circuit,

wherein the first circuit is configured to perform a plurality of functions, and

wherein the second circuit is configured to select one of the plurality of functions by controlling a conduction state of the switch.

2. The display device according to claim 1, wherein the second circuit includes a passive element.

3. The display device according to claim 1, wherein the first circuit is a read circuit in a driver circuit portion of the display device.

4. The display device according to claim 1,

wherein the plurality of functions include a function as an integrator circuit, a function as a voltage follower circuit, a function as a comparator circuit, and a function as a circuit to supply a predetermined voltage to the pixel.

5. The display device according to claim 1, wherein the display element is a light-emitting element.

6. A display device comprising:

a pixel comprising a transistor and a display element;

a first circuit comprising a second circuit and an operational amplifier electrically connected to the second circuit, the second circuit comprising a capacitor;

a first wiring; and

a second wiring,

wherein the transistor is electrically connected to the second circuit through the first wiring,

wherein one electrode of the capacitor is electrically connected to an inverting input terminal of the operational amplifier,

wherein the other electrode of the capacitor is electrically connected to an output terminal of the operational amplifier,

wherein the second circuit is configured to select whether the inverting input terminal of the operational amplifier is electrically connected to the first wiring or to the output terminal of the operational amplifier, and

wherein the second circuit is configured to select whether a non-inverting input terminal of the operational amplifier is electrically connected to the first wiring or to the second wiring.

7. The display device according to claim 6,

wherein the second circuit includes a first switch, a second switch, a third switch, and a fourth switch,

wherein the inverting input terminal of the operational amplifier is electrically connected to the first wiring through the first switch,

wherein the non-inverting input terminal of the operational amplifier is electrically connected to the first wiring through the second switch,

wherein the non-inverting input terminal of the operational amplifier is electrically connected to the second wiring through the third switch, and

wherein the output terminal of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier through the fourth switch.

8. The display device according to claim 6, wherein the first circuit is a read circuit in a driver circuit portion of the display device.

9. The display device according to claim 6,

wherein the first circuit is configured to perform a plurality of functions, and

wherein the second circuit is configured to select one of the plurality of functions, the plurality of functions including a function as an integrator circuit, a function as a voltage follower circuit, a function as a comparator circuit, and a function as a circuit to supply a predetermined voltage to the pixel.

10. The display device according to claim 6, wherein the display element is a light-emitting element.

11. The display device according to claim 6, wherein the second wiring is configured to supply a reference potential.

12. A display device comprising:

a pixel comprising a transistor and a display element;

a first circuit comprising a second circuit and an operational amplifier electrically connected to the second circuit, the second circuit comprising a resistor;

a first wiring; and

a second wiring,

wherein the transistor is electrically connected to the second circuit through the first wiring,

wherein one electrode of the resistor is electrically connected to an output terminal of the operational amplifier,

wherein the second circuit is configured to select whether an inverting input terminal of the operational amplifier is electrically connected to the first wiring and the other electrode of the resistor or to the output terminal of the operational amplifier, and

wherein the second circuit is configured to select whether a non-inverting input terminal of the operational amplifier is electrically connected to the first wiring or to the second wiring.

13. The display device according to claim 12,

wherein the second circuit includes a first switch, a second switch, a third switch, a fourth switch, and a fifth switch,

wherein the inverting input terminal of the operational amplifier is electrically connected to the first wiring through the first switch,

wherein the non-inverting input terminal of the operational amplifier is electrically connected to the first wiring through the second switch,

wherein the non-inverting input terminal of the operational amplifier is electrically connected to the second wiring through the third switch,

wherein the output terminal of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier through the fourth switch, and

wherein the other electrode of the resistor is electrically connected to the inverting input terminal of the operational amplifier through the fifth switch.

14. The display device according to claim 12, wherein the first circuit is a read circuit in a driver circuit portion of the display device.

15. The display device according to claim 12,

wherein the first circuit is configured to perform a plurality of functions, and

wherein the second circuit is configured to select one of the plurality of functions, the plurality of functions including a function as a current-voltage converter circuit and a function as a voltage follower circuit.

16. The display device according to claim 12, wherein the display element is a light-emitting element.

17. The display device according to claim 12, wherein the second wiring is configured to supply a reference potential.

18. A display device comprising:

a pixel comprising a transistor and a display element;

a first circuit comprising a second circuit and an operational amplifier electrically connected to the second circuit, the second circuit comprising a capacitor, a resistor, and a first switch;

a first wiring; and

a second wiring,

wherein the transistor is electrically connected to the second circuit through the first wiring,

wherein one electrode of the capacitor is electrically connected to an output terminal of the operational amplifier,

wherein one electrode of the resistor is electrically connected to the output terminal of the operational amplifier,

wherein an inverting input terminal of the operational amplifier is electrically connected to the first wiring,

wherein a non-inverting input terminal of the operational amplifier is electrically connected to the second wiring,

wherein the output terminal of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier through the first switch, and

wherein the second circuit is configured to select whether the inverting input terminal of the operational amplifier is electrically connected to the other electrode of the capacitor or to the other electrode of the resistor.

19. The display device according to claim 18,

wherein the second circuit further includes a second switch and a third switch,

wherein the inverting input terminal of the operational amplifier is electrically connected to the other electrode of the capacitor through the second switch, and

wherein the inverting input terminal of the operational amplifier is electrically connected to the other electrode of the resistor through the third switch.

20. The display device according to claim 18, wherein the first circuit is a read circuit in a driver circuit portion of the display device.

21. The display device according to claim 18,

wherein the first circuit is configured to perform a plurality of functions, and

wherein the second circuit is configured to select one of the plurality of functions, the plurality of functions including a function as an integrator circuit, a function as a voltage follower circuit, a function as a comparator circuit, and a function as a circuit to supply a predetermined voltage to the pixel.

22. The display device according to claim 18, wherein the display element is a light-emitting element.

23. The display device according to claim 18, wherein the second wiring is configured to supply a reference potential.

24. A display module comprising:

the display device according to claim 18; and

a circuit board, an FPC, or a touch sensor.

25. An electronic device comprising:

the display device according to claim 18; and

a speaker, a microphone, an operation key, or a housing.