Touch panel data entry device for thin film electroluminescent panels

• US 4,740,781 A
• Filed: 02/08/1985
• Issued: 04/26/1988
• Est. Priority Date: 02/08/1985
• Status: Expired due to Term

• Current Assignee: ITT Corporation (ITT, Inc.)
• Original Assignee: ITT Gilfillan
• Inventors: Brown, Kenneth A.
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): Fatahiyar, Mahmoud
• Application Number:
  US06/699,971
• Time in Patent Office: 1,173 Days
• Field of Search: 340/712, 340/365 C, 340/781, 340/760, 178/18, 178/19, 315/169.3, 315/169.4
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A touch-sensitive device for computer data entry from the presentation on a scanned, thin-film, electroluminescent display. A transparent conductive film is suspended over the display face. Touching that film at a predetermined point in the display capacitively couples scanning voltages (which are time-base synchronous and related to the touched point) to an amplifier and then to a utilization device (computer, for example).

Claims

1. A display system with touch-panel, soft-key switch for discrete data identification and touch selection, comprising:

a TFEL panel display having an electro-luminescent member and a non-conductive, transparent substrate through which said display is viewed;

a matrix of electrodes within said TFEL display arranged to be responsive to electrical scanning signals;

scanning means connected to said matrix to provide said scannig signals for producing a moving electric field normal to the plane of said luminescent member in synchronism with an externally supplied time base for image production;

and a flexible, transparent, insulating, touch membrane arranged parallel to said non-conductive, transparent substrate, and spaced therefrom, said membrane including a transparent conductive layer facing said transparent substrate whereby capacitance coupled signals produced by said scanning signals are extant at said conductive layer and appear in greater amplitude corresponding to the increased capacitive coupling at a location where said membrane is depressed toward said transparent substrate and

mean conductively attached to said membrane conductive layer to provide a signal output terminal.

3. A system according to claim 1 in which said TFEL panel display luminescent member is a zinc sulfide:

manganese phosphor film.

5. A system according to claim 1 in which said transparent conductive layer on said touch membrane is an indium tin oxide film.

7. A system according to claim 1 in which said TFEL panel display is further defined as including a pair of dielectric layers, said layers being disposed, one against each face of said planar luminescent member thereby to insulate said luminescent member from said electrode matrix.

9. The system according to claim 1 in which said matrix of electrodes comprises first and second close-spaced pluralities of discrete, generally parallel, narrow, conductive film elements, said first film elements extending in a first direction and said second film elements extending in a second direction substantially normal to said first direction.

11. The system according to claim 1 in which said transparent conductive layer comprises a plurality of generally parallel strips of indium tin oxide film, said strips being arranged to overlay predetermined areas of said panel display.

13. The system of claim 7 in which said transparent substrate is glass, and in which a base layer of black insulating material is provided, and said glass substrate and said base layer sandwich said electroluminescent member, said electrode matrix and said dielectric layers therebetween.

15. The system according to claim 1 in which a dielectric separator layer is inserted between said conductive layer and said transparent substrate, said separator layer having a plurality of apertures at predetermined locations, thereby to maintian the spacing of said touch membrane conductive layer from said transparent substrate except where said touch membrane is depressed in an area subtended by one of said apertures.

18. The combination according to claim 5 includes a high input impedance amplifier having its input connected to said touch membrane transparent conductive layer, the output of said amplifier providing a signal output to a utilization device.

2. A touch panel, soft-key switch system operatively associated with a TFEL panel display, said display including a planar luminescent member and a non-conductive transparent substrate through which said display is viewed, comprising:

a two coordinate matrix of electrodes within said TFEL display arranged to be responsive to corresponding two-coordinate electrical scanning signals, said electrodes corresponding to each of said coordinates being electrically insulated from each other;

first means responsive to an externally generated time base for generating and applying scanning signals to said matrix of electrodes to produce a moving electric field in two coordinates, said first means including means for amplitudes modulating said scanning signals to a level producing luminescence of said luminescent member in accordance with a data input signal to provide a corresponding visual data presentation on said panel display;

second means comprising a flexible planar, transparent touch membrane disposed parallel to and spaced from said transparent substrate, said second means including a transparent conductive layer carried by said touch member on its surface nearest said transparent substrate; and

third means comprising an amplifier having its input connected to said touch membrane conductive layer for producing an output signal including a substantially uniform fraction of said scanning signals capacitively coupled into said touch member conductive layer, said capacitively coupled signals being increased in amplitude when said touch membrane is deflected toward said transparent substrate, said signals of increased amplitude thereby corresponding to the area of said deflection on said touch membrane.

4. A system according to claim 2 wherein said TFEL panel display planar luminescent member is a zinc sulfide:

manganese phosphor film.

6. A system according to claim 2 in which said transparent conductive layer carried by said touch membrane is an indium tin oxide film.

8. A system according to claim 2 in which said TFEL panel display is further defined as including a pair of dielectric layers, said layers being disposed, one against each face of said planar luminescent member thereby to insulate said luminescent member from said electrode matrix.

10. The system according to claim 2 in which said electrode matrix comprises first and second close-spaced pluralities of discrete, generally parallel, narrow, conductive film elements, said first film elements extending in a first direction and said second film elements extending in a second direction substantially normal to said first direction.

12. The system according to claim 2 in which said touch membrane transparent conductive layer comprises a plurality of generally parallel strips of indium tin oxide film, said strips being arranged to overlay predetermined areas of said panel display.

14. The system of claim 8 in which said transparent substrate is glass, and in which a base layer of black insulating material is provided, and said glass substrate and said base layer sandwich said electroluminescent member, said elecrode matrix and said dielectric layers therebetween.

16. The system according to claim 2 in which a dielectric separator layer is inserted between said touch membrane conductive layer and said transparent substrate, said separator layer having a plurality of apertures at predetermined locations, thereby to maintain the spacing of said touch membrane conductive layer from said transparent substrate except where said touch membrane is depressed in an area subtended by one of said apertures.

17. The system according to claim 2 further defined in that said amplifier is a high input impedance amplifier.