DISPLAY DEVICE, DISPLAY MODULE, AND ELECTRONIC DEVICE

• US 20150301422A1
• Filed: 04/13/2015
• Published: 10/22/2015
• Est. Priority Date: 04/22/2014
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: MIYAKE, Hiroyuki, KUSUNOKI, Koji, ISHITANI, Tetsuji, HATSUMI, Ryo
• Granted Patent: US 10,345,661 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

To provide a display device with a novel structure that can achieve both thickness reduction and favorable display quality. In a structure of a display device including a liquid crystal layer between a pixel electrode and a counter electrode, a common electrode and an electrode of a capacitor in a touch sensor on the counter electrode side are formed integrally and supplied with a pulse signal. On the element substrate side, a signal to be supplied to a capacitor line that forms a capacitance with the pixel electrode is in conjunction with the pulse signal so as to cancel a change in an electric field applied to the liquid crystal layer. Such a structure can achieve a display device with a touch sensor function that can cancel a change in an electric field applied to a liquid crystal layer even when the electric field is changed by a pulse signal.

Claims

1. A display device comprising a first substrate, a second substrate, and a liquid crystal layer, further comprising:

a first transistor;

a first capacitor;

a first wiring;

a first electrode;

a second transistor;

a second electrode;

a second capacitor; and

a third electrode,

wherein the liquid crystal layer is provided between the first electrode and the third electrode,

wherein the first transistor, the first capacitor, the first wiring, and the first electrode are provided for the first substrate,

wherein the first transistor is electrically connected to the first electrode,

wherein the first electrode has a function as a pixel electrode of the liquid crystal layer,

wherein one electrode of the first capacitor is electrically connected to the first electrode,

wherein the other electrode of the first capacitor is electrically connected to the first wiring,

wherein the first wiring is configured to be supplied with a first signal,

wherein the second transistor, the second electrode, the second capacitor, and the third electrode are provided for the second substrate,

wherein one of a source and a drain of the second transistor is electrically connected to the second electrode,

wherein the second electrode has a function as one electrode of the second capacitor,

wherein the third electrode has a function as the other electrode of the second capacitor,

wherein the third electrode has a function as a counter electrode of the liquid crystal layer,

wherein the third electrode is configured to be supplied with a second signal, and

wherein the second signal is synchronized with the first signal.

2. The display device according to claim 1,

wherein the second substrate includes a third transistor and a fourth transistor,

wherein a gate of the third transistor is electrically connected to the second electrode,

wherein the other of the source and the drain of the second transistor is electrically connected to a second wiring,

wherein the second wiring is configured to be supplied with a constant potential,

wherein one of a source and a drain of the third transistor is electrically connected to one of a source and a drain of the fourth transistor,

wherein the other of the source and the drain of the fourth transistor is electrically connected to a third wiring, and

wherein the third wiring is configured to change a potential thereof depending on a potential of the second electrode.

3. The display device according to claim 2,

wherein the second transistor and the third transistor include an oxide semiconductor layer.

4. The display device according to claim 3,

wherein the second electrode is provided in the same layer as the oxide semiconductor layer in the second transistor.

5. The display device according to claim 1,

wherein the first transistor includes an oxide semiconductor layer which includes a first metal element,

wherein the other electrode of the first capacitor includes the first metal element and oxygen,

wherein the oxide semiconductor layer includes a region having a first hydrogen concentration, and

wherein the other electrode of the first capacitor includes a region having a second hydrogen concentration which is different from the first hydrogen concentration.

6. A display module comprising:

the display device according to claim 1; and

a printed board electrically connected to the display device.

7. An electronic device comprising:

the display module according to claim 6; and

an operation button.

8. A display device comprising:

a first transistor and a first capacitor electrically connected to each other;

a liquid crystal element over the first transistor and the first capacitor, the liquid crystal element comprising a first electrode and a second electrode with a liquid crystal layer interposed therebetween;

a second transistor and a second capacitor electrically connected to each other, the second transistor and the second capacitor being over the liquid crystal layer; and

a third electrode electrically connected to the second transistor, the third electrode being included in the second capacitor,

wherein the first electrode is electrically connected to the first transistor and the first capacitor,

wherein the second electrode is one of electrodes of the second capacitor, and

wherein the display device is configured so that signals input to the second electrode and one of electrodes of the first capacitor are synchronized with each other.

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

a third transistor and a fourth transistor,

wherein a gate of the third transistor is electrically connected to the third electrodes of the second capacitor,

wherein one of a source and a drain of the second transistor is electrically connected to a first wiring,

wherein the first wiring is configured to be supplied with a constant potential,

wherein one of a source and a drain of the third transistor is electrically connected to one of a source and a drain of the fourth transistor,

wherein the other of the source and the drain of the fourth transistor is electrically connected to a second wiring, and

wherein the second wiring is configured to change a potential thereof depending on a potential of the second electrode.

10. The display device according to claim 9,

wherein the second transistor and the third transistor include an oxide semiconductor layer.

11. The display device according to claim 10,

wherein the third electrode of the second capacitor is provided in the same layer as the oxide semiconductor layer in the second transistor.

12. The display device according to claim 8,

wherein the first transistor includes an oxide semiconductor layer which includes a first metal element,

wherein the one of the electrodes of the first capacitor includes the first metal element and oxygen,

wherein the oxide semiconductor layer includes a region having a first hydrogen concentration, and

wherein the one of the electrodes of the first capacitor includes a region having a second hydrogen concentration which is different from the first hydrogen concentration.

13. A display module comprising:

the display device according to claim 8; and

a printed board electrically connected to the display device.

14. An electronic device comprising:

the display module according to claim 13; and

an operation button.