Touch panel and electronic device

• US 10,156,930 B2
• Filed: 08/23/2016
• Issued: 12/18/2018
• Est. Priority Date: 04/07/2014
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kano, Hidekazu, Mori, Kenichi
• Primary Examiner(s): Dharia, Prabodh M
• Application Number:
  US15/244,445
• Publication Number:
  US 20160357331A1
• Time in Patent Office: 847 Days
• Field of Search: 345156-184, 349 42, 381 55
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 touch panel includes a capacitive touch panel unit and a pressure sensor unit. The capacitive touch panel unit includes a film and touch panel electrodes, and the pressure sensor unit includes a film and pressure sensor electrodes. An electrode layer in which the pressure sensor electrode is formed is the same as an electrode layer in which the touch panel electrode is formed. An electrode layer in which the pressure sensor electrode is formed has a non-formation portion where the pressure sensor electrode is not formed at the position opposite to the touch panel electrode.

Claims

1. A touch panel, comprising:

a capacitive unit including first and second sets of touch panel electrodes separated by a dielectric flat film and lying in first and second planes, respectively, the individual electrodes of the second set extending parallel to one another with respective gaps located between adjacent touch panel electrodes of the second set; and

a pressure sensor unit including first and second sets of parallel pressure sensor electrodes separated by a piezoelectric flat film and lying in the second and a third plane, respectively, each pressure sensitive electrode of the first set being located in a respective one of the gaps between the individual touch panel electrodes of the second set, each pressure sensor electrode of the second set opposing a respective pressure sensitive electrode of the first set with the piezoelectric film located there between so as to define an opposing pair of pressure sensitive electrodes, each pressure sensitive electrode of the second set having a respective length and width, the length of each pressure sensitive electrode of the second set being longer than its width, none of the pressure sensitive electrodes of the second set overlapping any of the touch panel electrodes of the second set by more than ten percent of its width.

2. The touch panel according to claim 1, wherein there is a respective gap in the third plane between each adjacent pairs of second pressure sensor electrodes, each gap opposing a respective one of the second touch panel electrodes, and there is no active electrode formed in the gaps between the adjacent pairs of second pressure sensor electrodes.

3. The touch panel according to claim 1, wherein the first, second and third planes are parallel to one another.

4. The touch panel according to claim 1, wherein the first set of touch panel, electrodes run parallel to one another and perpendicular to the second set of touch panel electrodes.

5. The touch panel according to claim 1, wherein each of the second pressure sensor electrodes extends entirely across a respective one of the gaps between adjacent touch panel electrodes of the second set of touch panel electrodes.

6. The touch panel according to claim 1, further comprising a pressure detection circuit connected to the first and second sets of pressure sensor electrodes.

7. The touch panel according to claim 6, wherein one of the first and second sets of pressure sensitive electrodes are connected to a ground potential.

8. The touch panel according to claim 6, wherein at least two of the opposing pairs of pressure sensitive electrodes are coupled to the pressure detection circuit in parallel to one another.

9. The touch panel according to claim 1, wherein the piezoelectric film is rectangular in shape and extends in a longitudinal direction and a lateral direction and the first and second sets of pressure sensitive electrodes extend in the longitudinal direction.

10. The touch panel display of claim 9, further comprising first and second pressure detection circuits, a first plurality of opposing pairs of pressure sensitive electrodes being connected to the first pressure detection circuit, a second plurality of opposing pairs of pressure sensitive electrodes being connected to the second pressure detection circuit, the location of the first plurality of opposing pairs of pressure sensitive electrodes being closer to the middle of the piezoelectric film in the longitudinal direction than the location of the second plurality of pairs of pressure sensitive electrodes.

11. The touch panel according to claim 9, wherein the pressure sensor has a charge inversion region adjacent longitudinal ends of the rectangular piezoelectric film and wherein at least some of the second pressure sensitive electrodes located in the inversion region have sections with narrowed widths.

12. The touch panel according to claim 1, wherein the piezoelectric film is made of polylactic acid which has been subjected to a stretching process in at least uniaxial direction.

13. The touch panel according to claim 1, wherein the electrode width of each of the first pressure sensor electrodes is smaller than the electrode width of each of the second pressure sensor electrodes.

14. The touch panel according to claim 1, wherein the electrode width of each of the second pressure sensor electrodes is smaller than the electrode width of each of the first pressure sensor electrodes.

15. The touch panel according to claim 1, further comprising a ground electrode located in the second plane and between a respective adjacent pair of first pressure sensor and second touch panel electrodes.

16. The touch panel according to claim 1, wherein there is a respective gap between respective adjacent second pressure sensitive electrodes in the third plane, a respective dummy electrode located in each gap in the third plane such that each respective dummy electrode opposes a respective second touch panel electrode, each dummy electrode being electrically isolated from the other electrodes.

17. The touch panel according to claim 1, wherein the second set of touch panel electrodes are formed on a surface of a third film located between the dielectric and piezoelectric films.

18. The touch panel according to claim 17, wherein the second pressure sensor electrodes are formed on a fourth film located adjacent the piezoelectric film but not between the piezoelectric and dielectric films.

19. An electronic device comprising:

the touch panel according to claim 1, and

a control unit receiving an output from the touch panel as an operation signal.

20. A touch panel, comprising:

a capacitive unit including first and second sets of touch panel electrodes separated by a dielectric flat film and lying in first and second planes, respectively, the individual electrodes of the second set extending parallel to one another with respective gaps located between adjacent touch panel electrodes of the second set; and

a pressure sensor unit including first and second sets of parallel pressure sensor electrodes separated by a piezoelectric flat film and lying in the second and a third plane, respectively, each pressure sensitive electrode of the first set being located in a respective one of the gaps between the individual touch panel electrodes of the second set, each pressure sensor electrode of the second set extending parallel to the pressure sensitive electrodes of the first set and opposing a respective pressure sensitive electrode of the first set with the piezoelectric film located there between so as to define an opposing pair of pressure sensitive electrodes.