Display device

• US 10,429,984 B2
• Filed: 05/25/2017
• Issued: 10/01/2019
• Est. Priority Date: 06/01/2016
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Matsumoto, Yuko, Naganuma, Tomohiko
• Primary Examiner(s): Tung, David
• Application Number:
  US15/604,764
• Publication Number:
  US 20170351358A1
• Time in Patent Office: 859 Days
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• 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
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens

Abstract

A sensing circuit is configured to measure a first physical quantity corresponding to a first capacitance being a parasitic capacitance formed in at least one of electrode groups including a plurality of first electrodes and a plurality of second electrodes, to thereby detect that significant change has occurred in the first capacitance due to touching of a conductor when an obtained first measurement value is out of a first range. The sensing circuit is further configured to measure a second physical quantity corresponding to a second capacitance formed between each of the plurality of first electrodes and each of the plurality of second electrodes, to thereby detect that significant change has occurred in the second capacitance due to compression of an insulating elastic layer based on a pressing force when an obtained second measurement value is out of a second range.

Claims

1. A display device, comprising:

a substrate;

a plurality of pixels on the substrate;

a light emitting element layer at each of the plurality of pixels and having a structure in which a light emitting layer is sandwiched between a cathode and an anode;

an inorganic insulating layer on the light emitting element layer;

a plurality of first electrodes laminated on the inorganic insulating layer, the plurality of first electrodes extending in a first direction and being adjacent to each other in a second direction intersecting with the first direction;

a plurality of second electrodes laminated on the inorganic insulating layer, the plurality of second electrodes extending in the second direction and being adjacent to each other in the first direction,

a plurality of elastic layers interposed between the plurality of first electrodes and the plurality of second electrodes in order to secure an interval between the plurality of first electrodes and the plurality of second electrodes, each of the plurality of elastic layers having an island-shape and overlapping with a corresponding one of the first electrodes and a corresponding one of the second electrodes in a plan view; and

a sensing circuit,

the sensing circuit being configured to measure a first physical quantity corresponding to a first capacitance being a parasitic capacitance formed in each of electrodes including the plurality of first electrodes and the plurality of second electrodes, to thereby detect that significant change has occurred in the first capacitance due to touching of a conductor when an obtained first measurement value is out of a first range,

the sensing circuit being further configured to measure a second physical quantity corresponding to a second capacitance formed between each of the plurality of first electrodes and each of the plurality of second electrodes, to thereby detect that significant change has occurred in the second capacitance due to compression of the plurality of elastic layers based on a pressing force when an obtained second measurement value is out of a second range, wherein

each of the plurality of pixels is positioned between a corresponding pair of the plurality of elastic layers.

2. The display device according to claim 1,

wherein the first physical quantity corresponds to a capacitance between each of the plurality of first electrodes and each of the plurality of second electrodes, and

wherein the first measurement value is out of the first range when the first measurement value is smaller than a first predetermined value.

3. The display device according to claim 1,

wherein the first physical quantity corresponds to a capacitance between a reference potential and each of the electrodes including the plurality of first electrodes and the plurality of second electrodes, and

wherein the first measurement value is out of the first range when the first measurement value is larger than a first predetermined value.

4. The display device according to claim 1, wherein the second measurement value is out of the second range when the second measurement value is larger than a second predetermined value.

5. The display device according to claim 1,

wherein the plurality of elastic layers are formed by dispersing particles in an organic layer, and

wherein the particles are more flexible than the organic layer.

6. The display device according to claim 5, wherein the organic layer is made of a resin.

7. The display device according to claim 6, wherein the particles are made of an organic material.

8. The display device according to claim 6, wherein the organic layer and the particles are made of the same material.

9. The display device according to claim 1, wherein, in the plan view, the plurality of elastic layers are prevented from being located at least at a part of positions at which the plurality of elastic layers and at least one group of the plurality of first electrodes and the plurality of second electrodes do not overlap each other.

10. The display device according to claim 1, wherein the insulating elastic layers comprise solid elastic layers and fluid elastic layers, respectively,

wherein, in the plan view, the solid elastic layers and the plurality of first electrodes are prevented from overlapping each other, and the solid elastic layers and the plurality of second electrodes overlap each other, and

wherein, in the plan view, the fluid elastic layers and overlapping regions of the plurality of first electrodes and the plurality of second electrodes overlap each other.

11. The display device according to claim 10,

wherein the plurality of second electrodes are fixedly bonded to the solid elastic layers, and

wherein the display device further comprises, on an opposite side to the insulating elastic layers and the plurality of first electrodes, a film fixedly bonded to the plurality of second electrodes.

12. The display device according to claim 10, wherein the fluid elastic layer comprises non-volatile liquid.

13. The display device according to claim 1, wherein

the plurality of second electrodes have a plurality of first areas overlapping with the plurality of elastic layers and the plurality of first electrodes,

the plurality of second electrodes have a second area overlapping with neither the plurality of elastic layers nor the plurality of first electrodes,

the plurality of first areas are changeable in height from the substrate, due to the compression of the plurality of elastic layers, and

the second area is unchangeable in height from the substrate, despite the pressing force, due to lack of the plurality of elastic layers under the second area.

14. The display device according to claim 1, wherein the elastic layer is made of a dielectric material.

15. The display device according to claim 14, wherein the dielectric material is polyurethane or cellulose acetate.