Transparent touch switching system

• US 4,516,112 A
• Filed: 02/22/1982
• Issued: 05/07/1985
• Est. Priority Date: 02/22/1982
• Status: Expired due to Fees

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Chen, Chee G.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US06/351,081
• Time in Patent Office: 1,170 Days
• Field of Search: 340/365 R, 340/365 A, 340/712, 340/711, 340/365 VL, 310/311, 310/330-332, 310/328, 310/325, 310/317, 310/319, 310/339, 310/800, 400/479.1, 400/479.2, 200/DIG. 1, 364/709, 179/90 K, 178/17 C
• US Class Current: 341/34
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• CPC Class Codes: H01H 2201/02 Piezo element
• CPC Class Codes: H01H 2219/012 programmable
• CPC Class Codes: Y10S 310/80 Piezoelectric polymers, e.g. PVDF

Abstract

A transparent touch switching system is provided for direct overlay on a display screen to enable operator input by merely touching the screen. A piezoelectric polymer film is supported above the screen for selective localized depression towards the screen. The film has transparent flexible conductive coatings on opposite sides thereof for voltage generation in response to depression of the film.

Claims

1. A transparent touch switching system comprising a display screen, a transparent flexible piezoelectric polymer film supported above said screen for selective localized bending depression by a user'"'"'s finger or the like towards said screen, said film having transparent flexible conductive coatings on opposite sides thereof for voltage generation in response to bending depression of said film, wherein said transparent flexible conductive coating on one side of said film is a continuous sheet, and said transparent flexible conductive coating on the other side of said film comprises a plurality of separate discrete sheet segments at selected separate areas, and comprising spacer means formed by a nonconductive transparent sheet supporting said piezoelectric polymer film above said screen and having a plurality of apertures through said sheet forming a waffle-like grid or matrix with each aperture aligned beneath a designated said discrete sheet segment, and including circuit connection means connected to said coatings for using said voltage as a trigger signal to drive designated circuitry.

2. A transparent touch switching system comprising:

a display screen;

a transparent flexible piezoelectric polymer film coated on one side with a continuous transparent flexible conductive sheet and coated on the other side at selected separate areas with a plurality of discrete transparent flexible conductive sheet segments;

spacer means supporting said piezoelectric polymer film above said screen, with designated said discrete sheet segments above designated sections of said screen, said spacer means comprising a nonconductive transparent sheet with a plurality of apertures therethrough forming a waffle-like grid or matrix, each said aperture aligned beneath a designated said discrete sheet segment such that said film may be bendingly depressed toward said screen in the localized areas of said discrete sheet segments; and

circuit connection means having a common terminal connected to said continuous sheet on said one side of said piezoelectric polymer film, and having a plurality of separate dedicated terminals each connected to a respective one of said discrete sheet segments on said other side of said piezoelectric polymer film, such that bending depression of said piezoelectric polymer film by a finger or the like above one of said designated sections of said screen causes a voltage to be developed between said common terminal and the dedicated terminal connected to the corresponding discrete sheet segment, said voltage being usable as a trigger signal to drive designated circuitry.

3. The invention according to claim 2 comprising a front flexible transparent protective cover above said piezoelectric polymer film and its top side coating for touch actuation by a user.