Multi-channel position detection system

The invention is a multi-channel position detection system which utilizes several separate emitters and a single photodetector to, for example, align a multi-lead component manipulator with a predetermined location in a printed circuit board. An oscillator circuit generates a modulated signal for each emitter and a multiplier circuit develops an output signal based upon the oscillator output and the photodetector output. The photodetector provides an output responsive to the emitter signal as attenuated by the circuit board location relative to the emitter. When the lead hole of the circuit board is aligned with the emitter and photodetector minimum attenuation of the signal occurs.

What is claimed is:

1. A multi-channel position detection system for an industrial manipulator which has individual means for engaging and manipulating each of the separate leads of a multi-lead component for the insertion of said leads into a predetermined hole pattern location in a circuit board, said system comprising:

a first emitter means in one of said lead engaging means proximate the component lead and at least a second emitter means in another of said lead engaging means;

a photodetector disposed below the predetermined hole pattern location of the circuit board;

circuit means for generating a distinct modulated signal for each of said emitters whereby each of said emitters generates a modulated output to which said photodetector is responsive, said emitter output received by the photodetector being attenuated according to whether the emitter output passes through the circuit board hole or is at least in part blocked by the circuit board and whereby said photodetector generates an output responsive to said emitter output; and

circuit means responsive to each said modulated signal and said detector output signal as based on each attenuated emitter output signals for generating a separate output signal for each said emitter output, whereby minimal attenuation of each modulated emitter output indicates lead relationship to the predetermined circuit board hole locations.

2. The multi-channel position detection system according to claim 1 wherein the industrial manipulator engaging means include motive means for effecting the movement thereof and the component lead and wherein said motive means are responsive to the output of the circuit means responsive to the modulated signal and photodetector output signal.

3. The multi-channel position detection system according to claim 2 wherein the circuit means responsive to each modulated signal and the detector output signal is a frequency division multiplexing circuit which provides an output to which the motive means of the engaging means is responsive.

4. The multi-channel position detection system according to claim 3 wherein the industrial manipulator has three individual lead engaging means and an emitter means is disposed in each of said lead engaging means and wherein the circuit means for generating a modulated signal for each said emitter includes an oscillator circuit means and an infrared emitter driver circuit means.

5. The multi-channel position detector system according to claim 4 wherein the circuit means responsive to the detector output signal includes preamp circuit means and filter means.

6. A method for locating a predetermined hole pattern in a circuit board for the insertion of each of the separate leads of a multi-lead component thereinto by an industrial manipulator which has individual means for engaging and manipulating each of the separate leads, and which manipulator has a first emitter means in one of the individual lead engaging means proximate the component lead and at least a second emitter means in another of the individual lead engaging means and wherein a photodetector means is disposed below the predetermined hole pattern location of the circuit board, said method comprising the steps of:

generating a first distinct modulated signal and at least a second distinct modulated signal, each of said signals being detected by said photodetector means;

emitting said first distinct modulated signal from the at least first emitter means and emitting the at least second distinct modulated signal from the at least second emitter means, whereby the emitted signals are directed toward the photodetector means;

effecting relative movement between the signals and the circuit board whereby signals passing through a hole therein are received by the photodetector means and attenuated according to whether the emitter output passes through the hole or is at least in part blocked by the circuit board; and

determining the degree of attenuation of each signal received by the photodetector means whereby minimized attentuation of each modulated emitter output indicates alignment with a pretermined hole pattern in the circuit board.