Browse Prior Art Database

Coordinate Locator

IP.com Disclosure Number: IPCOM000084279D
Original Publication Date: 1975-Oct-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 3 page(s) / 47K

Publishing Venue

IBM

Related People

Hoo, SK: AUTHOR

Abstract

In certain display devices and particularly in interactive terminals, it is desirable to provide a locate function in which a user uses a light pen or stylus to point at a spot on the display surface and the locator gives the X-Y coordinates of this spot.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Coordinate Locator

In certain display devices and particularly in interactive terminals, it is desirable to provide a locate function in which a user uses a light pen or stylus to point at a spot on the display surface and the locator gives the X-Y coordinates of this spot.

A method for providing this function in displays such as in electrostatic or deformographic storage display tubes, graphic data tablets, or plasma display panels operates as follows: The locator consists of two sections, a visually transparent surface containing a coded grid mounted over the working area such as a display surface, and a reader in the form of a light pen which illuminates and reads the coded grid to identify the specific location.

The coded grid is a two-tone (black and white) image, which contains the explicit X-Y coordinates of all the points that a user may wish to point at on the display surface. A transparent surface 3 can be of any material such as glass plate, film, etc., on the surface of which a virtually transparent microscopic code is deposited. The coded grid can be formed by a thin-metallic film deposited using the normal photoetching process, in which every coordinate of interest on the surface has a code which identifies its explicit location.

The light pen contains two main devices, a light-emitting diode (LED) light source 5 and focusing optics 7 which collects and images the reflected light generated by the LED light source onto a self-scanned area sensor array 9. The sensor array 9 reads the light reflected from the codes deposited on transparent surface 3, and in a preferred embodiment comprises a charge-coupled device.

When the light pen is depressed against the surface 3, a normally open contact switch 11 is closed. This in turn turns on the LED light source 5 and sends a start...