Browse Prior Art Database

Color Indicating Position Locater for a CRT

IP.com Disclosure Number: IPCOM000039605D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 3 page(s) / 61K

Publishing Venue

IBM

Related People

Broockman, EC: AUTHOR [+2]

Abstract

A passive probe is provided with a retroreflective material and a graduated light filter material to provide, to an operator of a data processing terminal system, a means to input data into the system, for example, to change the color of the CRT display associated with the system, to display numerical data, or to input other information. Fig. 1 illustrates a known system for detecting the X-Y position of a probe 1 relative to the face of a CRT 2. A light source 3, such as a light emitting diode (LED), produces a beam which is directed by a mirror 4 to a rotating polygon mirror 5 which has two sets of facets, one causing the beam to scan across a bar code picket fence 6 surrounding three sides of the CRT as illustrated by solid lines 7A, 7B.

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Color Indicating Position Locater for a CRT

A passive probe is provided with a retroreflective material and a graduated light filter material to provide, to an operator of a data processing terminal system, a means to input data into the system, for example, to change the color of the CRT display associated with the system, to display numerical data, or to input other information. Fig. 1 illustrates a known system for detecting the X-Y position of a probe 1 relative to the face of a CRT 2. A light source 3, such as a light emitting diode (LED), produces a beam which is directed by a mirror 4 to a rotating polygon mirror 5 which has two sets of facets, one causing the beam to scan across a bar code picket fence 6 surrounding three sides of the CRT as illustrated by solid lines 7A, 7B. The other set of facets causes the beam to scan across the right and upper sides of 6 after being reflected off a mirror 9, as illustrated by broken lines 8A, 8B. The top half is removed from the left side of 6 to permit 8A, 8B to reach 9. Retroreflective light retraces from the picket fence 6 to a photodetector 10 via rotating polygon mirror 5, (5 and 9 for lines 8A, 8B) and a light-collecting lens 11. When probe 1 is placed against the CRT, the two sets of scanning lines are interrupted when they reach probe 1 and retroreflective light is not returned to photodetector 10. By counting the number of bars (on 6)

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detected after detection of the "home" bar code at 12, the directions of the lines 7 and 8 when they impinge upon 1 can be calculated by an associated processor
13. The X-Y position at the intersection of these two lines when they impinge upon 1 is then calculated by 13. The modifications to this known interactive system to achieve an additional operator data input will now be described. Fig. 2 is a cross section view of the preferred embodiment of the probe 1 which is cylindrical in shape. The outer layer 15 is a graduated light filter 15 surrounding an inner layer 16 of a retroreflective material. In the system of Fig. 1, 16 will cause a continuous reflection of the beam back to the photodetector 10 rather than interrupting the beam; however, this change from bar code reflections is similarly used to determine the X-Y position of 1 relative to the face of the CRT. The light filter material 15 is preferably fabricated by photographing the spectrum produced by a prism. The filter is then reproduced photographically. Fig. 3 shows the preferred form of light source 3 (Fig. 1) for producing a composite light beam comprised of two differing wavelengths. Thus, light sources 16 and 17 produce light beams of differing wavelengths which are combined into a single beam via lens 18 and 19, mirrors 20, 21, 22 and lens 23. In addition, a second photodetector 10A is provided to detect one of the two wavelengths while photodetector 10 detects the other. Appropriate filter...