Intrusion detection system for operating industrial machines with variable sensitivity

Claim 2

An optical intrusion detection system for enabling and/or disabling the operation of an associated industrial machine when an appropriate intrusion is detected, said system comprising: light transmitter means for generating a plurality of light beams so as to form a light curtain; light receiver means for sensing said light beams generated by said light transmitter means; and control means for operating said light transmitter means and light receiver means and controlling operation of the industrial machine, said control means comprising logic circuits for selectively (a) generating a first control signal for selectively enabling or disabling said machine when X or more light beams are blocked during a first phase of the operation of said machine, and (b) generating a second control signal for selectively enabling or disabling said machine when Y or more light beams are blocked during a second phase of the operation of said machine, wherein X and Y are both integers, X and Y are both >0, and X≠Y.

Claim 3

An optical intrusion detection system according to claim wherein said control means generates said first control signal for enabling said machine when X or more light beams are blocked and then unblocked during an idle phase of said machine, and generates said second control signal for disabling said machine when Y or more light beams are blocked during an operating phase of said machine.

Claim 4

An optical intrusion detection system according to claim 2 wherein X>1 and Y=1, whereby said control means will start said machine after said light curtain is momentarily interrupted by a relatively large object, and will stop said machine when said light curtain is thereafter interrupted by a relatively small object.

Claim 5

An optical intrusion detection system according to claim 1 wherein said logic circuits of said control means comprise means for determining whether an odd-numbered or even-numbered light beam is interrupted.

Claim 6

An optical intrusion detection system according to claim 1 wherein said control means comprises a microprocessor.

Claim 7

An optical intrusion detection system according to claim 2 wherein X>Y.

Claim 8

An optical intrusion detection system for enabling and/or disabling the operation of an associated industrial machine when an appropriate intrusion is detected, said system comprising: light transmitter means for generating a plurality of parallel spaced light beams so as to form a light curtain; light receiver means for sensing said light beams generated by said light transmitter means; and control means for operating said light transmitter means and light receiver means and controlling operation of the industrial machine, said control means comprising logic circuits for selectively (a) generating a first control signal for enabling said machine when X or more light beams are blocked and then unblocked during a first idle phase of the operation of said machine, and (b) generating a second control signal for disabling said machine when Y or more light beams are blocked during a second later operating phase of the operation of said machine, wherein X and Y are both integers, X and Y are both >0, and X>1 and Y=1, whereby said control means will start said machine after said light curtain is momentarily interrupted by a relatively large object, and will stop said machine when said light curtain is thereafter interrupted by a relatively small object.

Claim 9

An optical intrusion detection system for enabling and/or disabling the operation of an associated industrial machine when an appropriate intrusion is detected, said system comprising: light transmitter means for generating a plurality of parallel spaced light beams so as to form a light curtain; light receiver means for sensing said light beams generated by said light transmitter means; and control means for operating said light transmitter means and light receiver means and controlling operation of the industrial machine, said control means comprising logic circuits for selectively (a) generating a first control signal for enabling said machine when X or more light beams are blocked and then unblocked during a first idle phase of the operation of said machine, and (b) generating a second control signal for disabling said machine when Y or more light beams are blocked during a second later operating phase of the operation of said machine, wherein X and Y are both integers, X and Y are both >0, and X>1 and Y=1, whereby said control means will start said machine after said light curtain is momentarily interrupted by a relatively large object, and will stop said machine when said light curtain is thereafter interrupted by a relatively small object.

Claim 12

A method according to claim 8 wherein said machine is enabled when X or more light beams are blocked and then unblocked during an idle phase of said machine, and said machine is disabled when Y or more light beams are blocked during an operating phase of said machine.

Claim 13

A method according to claim 9 wherein X>Y.

Claim 14

A method according to claim 10 wherein X>1 and Y=1, whereby said machine will be enabled after said light curtain is momentarily interrupted by a relatively large object, and said machine will be disabled when said light curtain is thereafter interrupted by a relatively small object.

Claim 17

An optical intrusion detection system according to claim 1 wherein said light transmitter means generates a plurality of parallel spaced light beams.

Claim 18

An optical intrusion detection system for enabling and/or disabling the operation of an associated industrial machine when an appropriate intrusion is detected, said system comprising: light transmitter means for generating a plurality of light beams so as to form a light curtain; light receiver means for sensing said light beams generated by said light transmitter means; and control means for operating said light transmitter means and light receiver means and controlling operation of the industrial machine, said control means comprising logic circuits for selectively (a) generating a first control signal for selectively enabling said machine when X or more light beams are blocked during a first phase of the operation of said machine, and (b) generating a second control signal for selectively disabling said machine when Y or more light beams are blocked during a second phase of the operation of said machine, wherein X and Y are both integers, X and Y are both >0, and X≠Y.

Claim 19

An optical intrusion detection system for enabling and/or disabling the operation of an associated industrial machine when an appropriate intrusion is detected, said system comprising: light transmitter means for generating a plurality of light beams so as to form a light curtain; light receiver means for sensing said light beams generated by said light transmitter means; and control means for operating said light transmitter means and light receiver means and controlling operation of the industrial machine, said control means comprising logic circuits for selectively (a) generating a first control signal for selectively enabling said machine when X or more light beams are blocked during a first phase of the operation of said machine, and (b) generating a second control signal for selectively disabling said machine when Y or more light beams are blocked during a second phase of the operation of said machine, wherein X and Y are both integers, X and Y are both >0, and X≠Y.