Reduced noise touch screen apparatus and method
First Claim
1. A touch screen for determination of a touch position with a resolution of less than one inch, comprising:
- a computer screen having a display region with an exterior and an interior surface;
a transparent conductive coating placed directly on said exterior surface of said computer screen; and
a plurality of electrodes placed directly on said exterior surface of said computer screen and near edges thereof, in the absence of electrodes spaced from said exterior surface or placed on said interior surface.
0 Assignments
0 Petitions
Accused Products
Abstract
A touch screen having a high or fine resolution at relatively low cost is provided. In one embodiment, electrodes are placed directly on the surface of a CRT screen without the need for an electrode positioned on the rear surface. The touch screen may include a conductive coating and a protective coating which are preferably provided in a single vacuum chamber step. A high gain system including a high-frequency sampling bandpass filter provide discrimination of the desired signal over noise. A screen calibration technique is used to achieve linearization in order to convert the electric signals obtained from the screen into data indicative of the position of a touch on the screen.
147 Citations
19 Claims
-
1. A touch screen for determination of a touch position with a resolution of less than one inch, comprising:
-
a computer screen having a display region with an exterior and an interior surface;
a transparent conductive coating placed directly on said exterior surface of said computer screen; and
a plurality of electrodes placed directly on said exterior surface of said computer screen and near edges thereof, in the absence of electrodes spaced from said exterior surface or placed on said interior surface. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of making a touch screen apparatus for detecting touch at a preselected location on a touch screen surface with a resolution of less than one inch, comprising:
-
providing a computer screen, having a front surface;
applying a plurality of bar electrodes directly to the front surface;
depositing a transparent conductive coating directly on the front surface to provide an electrical path between the bar electrodes; and
applying a transparent protective coating over the conductive coating, said computer screen being free of electrodes spaced from said front surface. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
Specification