Browse Prior Art Database

Multiplexed Optical Sensing Arrangement

IP.com Disclosure Number: IPCOM000088832D
Original Publication Date: 1977-Aug-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Rohen, JE: AUTHOR

Abstract

Pairs of light transmitters and receivers are arranged to have the light beams between transmitters and receivers interrupted by a movable vane to thereby provide a digital output indicative of the location of the vane. Where such pairs are closely spaced, a problem of cross-talk can arise. A solution to this problem is to provide suitable multiplexing and strobing of the sensing pairs so that only the particular light source associated with a particular receiver is energized at any given time.

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 100% of the total text.

Page 1 of 2

Multiplexed Optical Sensing Arrangement

Pairs of light transmitters and receivers are arranged to have the light beams between transmitters and receivers interrupted by a movable vane to thereby provide a digital output indicative of the location of the vane. Where such pairs are closely spaced, a problem of cross-talk can arise. A solution to this problem is to provide suitable multiplexing and strobing of the sensing pairs so that only the particular light source associated with a particular receiver is energized at any given time.

The drawing shows an array of transmitters and receivers, such as A-H, with a vane 3 mounted on a pivot 5. As vane 3 sweeps through its arc, it interrupts the light between the transmitters and receivers at the different sensor locations. The sensor pairs are located in staggered relationship to provide increased resolution. The pairs (transmitter and associated receiver) can then be strobed sequentially, i,e,, A, B, C, D,...etc., and repetitively, and thus the light from each transmitter will not cause cross-talk in the adjacent receivers,

If sets of such paired sensors are arranged at right angles to each other, and a rotatable ball is used as a bearing 5, an optically.oriented X-Y joystick control can be obtained.

1

Page 2 of 2

2

[This page contains 1 picture or other non-text object]