Touch controlled display device

• US 4,910,504 A
• Filed: 01/11/1988
• Issued: 03/20/1990
• Est. Priority Date: 01/30/1984
• Status: Expired due to Term

• Current Assignee: Touch Display Systems AB
• Original Assignee: Touch Display Systems AB
• Inventors: Eriksson, Soren G.
• Primary Examiner(s): OBERLEY, ALVIN E
• Application Number:
  US07/143,202
• Time in Patent Office: 799 Days
• Field of Search: 340/365 C, 340/365 VL, 340/712, 340/784, 340/765, 341/33, 341/23, 200/DIG. 1, 400/479.1
• US Class Current: 345/174
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 2219/012 programmable
• CPC Class Codes: H01H 2231/016 Control panel; Graphic display; Programme control
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

A touch controlled display device has, in one embodiment, two displaying segments disposed on the inside of a front cover window in an LCD unit. Further to causing the segments to display different sign information by providing them with different feeds, they are both utilized as sensing means included in a capacitative sensing circuit which is activable by the finger of an operator.

Claims

1. In a touch controlled display device having first and second display electrodes disposed on the inside of a front cover window of said device capable of displaying information and a counter-electrode within said device, wherein said first and second electrodes and said counter-electrode cooperate to form a display means, and wherein said counter-electrode activates the display of said information, the improvement comprising said first and second electrodes being adapted for inclusion in a capacitive sensing circuit, wherein the capacitance between said first and second electrodes is measured by said capacitive sensing circuit.

2. The display device of claim 1 wherein said display is an LCD display having at least one LCD segment being included in said capacitive sensing circuit.

3. The display device of claim 2 wherein said display is adapted as a touch-activated switch, which is self-indicating by the segments being disposed for displaying different information.

4. The display device of claim 3 wherein said switch includes an LCD drive unit integrated therewith, said LCD drive unit also being included in said sensing circuit and being formed with a plurality of types of outputs.

5. The display device of claim 3 wherein said switch is formed as a sign-displaying matrix and said sensing circuit is connectable to a microprocessor.

6. The display device of claim 3 wherein a plurality of said switches are provided to form a keyboard means.

7. A touch controlled display device, said device comprising:

at least one first electrode capable of displaying information;

at least one second electrode capable of displaying information and positioned adjacent said first electrode and having a predetermined electrical capacitance therebetween, said capacitance changing when said first and second electrodes come in close proximity to the user, wherein the change in said capacitance is measured;

a counter-electrode which cooperates with said first electrode and said second electrode to form a display means, wherein said counter-electrode activates the display of said information;

display control means coupled to said first and second electrodes for controlling the display operation of said first and second electrodes; and

detector means coupled to said first and second electrodes for detecting said electrical capacitance, wherein in response to said first and second electrodes coming in close proximity to the user, said detector means provides a first signal when said capacitance is below a predetermined level and a second signal when said capacitance is above a predetermined level.

8. The touch controlled display device of claim 7 wherein said display control means is coupled to said detector means and controls said first and second electrodes to display information corresponding to whether said first and second electrodes have been touched.

9. The touch controlled display device of claim 7 further including a display window, said first and second electrodes being mounted to a surface of said window and the information displayed by said first and second electrodes being visible through said window.

10. The touch controlled display device of claim 9 wherein in response to the surface of said window being touched, said capacitance between said first and second electrodes changes and said change is detected by said detector means.

11. The touch controlled display device of claim 7 wherein said first and second electrodes form an LCD display.

12. The touch controlled display device of claim 7 further including a plurality of first and second electrodes arranged such that certain ones of said electrodes display information different from others of said electrodes.

13. The touch controlled display device of claim 12 wherein said plurality of first and second electrodes are coupled to said control means and are controlled by said control means.

14. The touch controlled display device of claim 13 wherein said certain ones of said electrodes display said information in response to coming into close proximity with the user.

15. The touch controlled display device of claim 13 wherein said plurality of first and second electrodes, said control means and said detector means are arranged to provide a plurality display elements and corresponding switch elements, the electrodes which form a particular display element also being used to form the corresponding switch element.