Display panel with pressure sensor and electronic device with pressing input function

• US 10,503,305 B2
• Filed: 11/04/2015
• Issued: 12/10/2019
• Est. Priority Date: 05/27/2013
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Ando, Masamichi, Tanimoto, Kazuhiro, Yoshida, Mitsunobu, Nishikawa, Shigeo
• Primary Examiner(s): Edouard, Patrick N
• Assistant Examiner(s): Fox, Joseph P
• Application Number:
  US14/931,947
• Publication Number:
  US 20160077649A1
• Time in Patent Office: 1,497 Days
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133531 characterised by the arrangement of polariser or analyser axes
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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: G09F 9/00 Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the variable information is permanently attached to a movable support G09F11/00; abacus G06C1/00; slide-rules G06G1/00

Abstract

An electronic device with pressing input function has a substantially rectangular parallelepiped-shaped housing. A display panel with pressure sensor and an arithmetic circuit module are disposed in the housing. The display panel with pressure sensor is composed of a pressure sensor and a display panel. In the display panel, a front polarizing plate is disposed on a front face of a liquid crystal panel. In the pressure sensor, electrodes are formed on both respective flat plate faces of a piezoelectric film having birefringence. The pressure sensor is disposed between the liquid crystal panel and the front polarizing plate of the display panel, and a uniaxial drawing direction of the piezoelectric film is parallel to a polarizing direction of the front polarizing plate.

Claims

1. A display panel comprising:

an image forming panel configured to control light emitted to a front face side to form a displayed image;

a front polarizing plate disposed adjacent the front face side of the image forming panel; and

a pressure sensor including a single film formed of only a single piezoelectric film that is a chiral polymer, wherein

the pressure sensor is disposed relative to the image forming panel such that a uniaxial drawing direction of the single film is parallel to or orthogonal to a polarizing direction of the front polarizing plate.

2. The display panel according to claim 1, wherein the pressure sensor is disposed between the front polarizing plate and the image forming panel.

3. The display panel according to claim 2, wherein only the front polarizing plate is present between an operation surface of the display panel and the pressure sensor.

4. The display panel according to claim 2, further comprising a position detecting sensor between the front polarizing plate and the pressure sensor.

5. An electronic device comprising:

the display panel according to claim 4;

an arithmetic unit configured to detect a pressing amount based on a first detection signal from the pressure sensor and a pressing position based on a second detection signal from the position detecting sensor; and

a housing defining a display surface, the housing being configured to accommodate the display panel and the arithmetic unit.

6. The display panel according to claim 1, wherein only the front polarizing plate is present between an operation surface of the display panel and the pressure sensor.

7. The display panel according to claim 1, wherein the chiral polymer is polylactic acid.

8. The display panel according to claim 7, wherein the polylactic acid is at least uniaxially drawn.

9. The display panel according to claim 1, further comprising a buffer member between the pressure sensor and the image forming panel.

10. The display panel according to claim 1, further comprising a position detecting sensor between the front polarizing plate and the image forming panel.

11. An electronic device comprising:

the display panel according to claim 10;

an arithmetic unit configured to detect a pressing amount based on a first detection signal from the pressure sensor and a pressing position based on a second detection signal from the position detecting sensor; and

a housing defining a display surface, the housing being configured to accommodate the display panel and the arithmetic unit.

12. The display panel according to claim 1, further comprising a position detecting sensor between the front polarizing plate and the pressure sensor.

13. An electronic device comprising:

the display panel according to claim 12;

an arithmetic unit configured to detect a pressing amount based on a first detection signal from the pressure sensor and a pressing position based on a second detection signal from the position detecting sensor; and

a housing defining a display surface, the housing being configured to accommodate the display panel and the arithmetic unit.

14. The display panel according to claim 1, wherein the pressure sensor includes a first set of electrodes configured to detect a pressure applied to the single piezoelectric film, and a second set of electrodes configured to detect a touch position of the single piezoelectric film.

15. An electronic device comprising:

the display panel according to claim 14;

an arithmetic unit configured to detect a pressing amount based on a first detection signal from the first set of electrodes and a pressing position based on a second detection signal from the second set of electrodes; and

a housing defining a display surface, the housing being configured to accommodate the display panel and the arithmetic unit.

16. The display panel according to claim 1, further comprising a rear polarizing plate disposed on a side of the image forming panel opposite to the front polarizing plate.

17. The display panel according to claim 16, further comprising a backlight disposed adjacent the rear polarizing plate.

18. An electronic device comprising:

the display panel according to claim 1;

an arithmetic unit configured to detect a pressing amount based on a detection signal from the pressure sensor; and

a housing defining a display surface, the housing being configured to accommodate the display panel and the arithmetic unit.