Coating control system

Claim 2

A control system for controlling resistivity of a deposit formed by deposition of metal on a moving substrate comprising transport means for continuously moving said substrate, deposition means mounted adjacent said substrate for depositing metal thereon, monitoring means mounted adjacent said substrate for monitoring a characteristic of the metal deposited thereon which is a function of resistivity thereof, said monitoring means providing a control signal, comparator means coupled with said monitoring means for receiving said control signal, said comparator means including a plurality of comparators for providing discrete output signals as a function of variation of said control signal respectively above and below a preset value representing a desired value of said characteristic, and coupling means coupling said comparator means to said deposition means and responsive to said output signals for controlling said deposition means upon the occurrence of predetermined changes of said characteristic for controlling said resistivity.

Claim 3

A control system as in claim 1 wherein said plurality of comparators comprises first and second comparators for providing discrete output signals when said control signal is a first magnitude respectively above and below said preset value, and comprises third and fourth comParators for providing discrete output signals when said control signal is a second magnitude respectively above and below said preset value, said second magnitude being greater than said first magnitude, and said coupling means couples the output signals of said first and second comparators to said deposition means to compensate for long term resistivity changes, and couples the output signals of said third and fourth comparators to said deposition means to compensate for short term resistivity changes.

Claim 4

A control system as in claim 1 wherein said characteristic monitored by said monitoring means includes electromagnetic transmission of the metallized substrate, and said desired value thereof is a percentage transmission value.

Claim 5

A control system as in claim 2 wherein said coupling means includes electromechanical means operating impedance means, said impedance means being coupled to control said deposition means, and said first and second comparators are coupled to said electromechanical means to control the operation thereof, and means couple said third and fourth comparators to said impedance means for affecting the impedance thereof.

Claim 6

A control system as in claim 2 wherein said coupling means includes a motor controlled impedance, the motor being controlled by said output signals of said first and second comparators and said impedance being coupled to control said deposition means, and fifth comparator means responsive to said monitoring means for controlling the speed of operation of said motor as a function of said characteristic of said metal deposit.

Claim 7

A control system for maintaining a variable substantially constant comprising means for monitoring said variable to detect a characteristic thereof and to provide a control signal which varies as a function of change of said characteristic comparator means coupled with said monitoring means for receiving said control signal, said comparator means comprising a first pair of comparators responsive to the limits of a first range of said control signal and respectively providing discrete output signals when said control signal varies to said limits, and a second pair of comparators for receiving said control signal and responsive to deviation thereof over a second greater range for providing discrete output signals when said control signal respectively reaches the limits of said second range, means for controlling said variable, and coupling means coupled between said comparator means and said means for controlling said variable and responsive to said discrete output signals from said first pair of comparators for compensating for long term drifts in said variable and responsive to said discrete output signals of said second pair of comparators for compensating for short term changes in said variable while providing non-electrically conductive path between said comparator means and said means for controlling said variable.

Claim 8

A control system for maintaining a variable substantially constant comprising means for monitoring said variable to detect a characteristic thereof and to provide a control signal which varies as a function of change of said characteristic comparator means coupled with said monitoring means for receiving said control signal, said comparator means comprising a first pair of comparators responsive to the limits of a first range of said control signal and respectively providing discrete output signals when said control signal varies to said limits, and a second pair of comparators for receiving said control signal and responsive to deviation thereof over a second greater range for providing discrete output signals when said control signal respectively reaches the limits of said second range, means for controlling said variable, and coupling means coupled between said comparator means and said means for controlling said variable and responsive to said discrete output signals from said first pair of comparators for compensating for long term drifts in said variable and responsive to said discrete output signals of said second pair of comparators for compensating for short term changes in said variable while providing non-electrically conductive path between said comparator means and said means for controlling said variable.

Claim 9

A control system for monitoring resistivity of a deposit formed by deposition of metal on a moving film substrate comprising means adapted to contain coating metal adjacent to the path of the moving film substrate, means for delivering vaporizing energy to said metal, means for supplying electric power to said means for delivering vaporizing energy, said means for supplying electric power being coupled with vaporizing energy control means, detection means adjacent said film substrate for continuously monitoring electromagnetic radiation emanant from the coated film substrate after deposition for providing an electrical signal, the magnitude of said signal being empirically related to the resistivity of the coated film substrate, comparison means coupled with said detection means for receiving said electrical signal, said comparison means including a comparator network for providing output signals as a function of variation of said electrical signal from first and second predetermined reference levels, and means operated by the control signal from said comparison means for operating said vaporizing energy control means whereby power to said means for delivering vaporizing energy is varied to control the resistivity of the deposit.

Claim 10

A control system for monitoring resistivity of a deposit formed by deposition of metal on a moving film substrate comprising means adapted to contain coating metal adjacent to the path of the moving film substrate, means for delivering vaporizing energy to said metal, means for supplying electric power to said means for delivering vaporizing energy, said means for supplying electric power being coupled with vaporizing energy control means, detection means adjacent said film substrate for continuously monitoring electromagnetic radiation emanant from the coated film substrate after deposition for providing an electrical signal, the magnitude of said signal being empirically related to the resistivity of the coated film substrate, comparison means coupled with said detection means for receiving said electrical signal, said comparison means including a comparator network for providing output signals as a function of variation of said electrical signal from first and second predetermined reference levels, and means operated by the control signal from said comparison means for operating said vaporizing energy control means whereby power to said means for delivering vaporizing energy is varied to control the resistivity of the deposit.

Claim 11

A control system for a vacuum deposition system for the maintenance of the required surface resistivity distribution of the deposit formed by vapor deposition of metal on a moving film substrate comprising means adapted to contain coating metal adjacent to the path of the film substrate, means for delivering vaporizing energy to said metal, means for supplying electric power to said means for delivering vaporizing energy, said means for supplying electric power being coupled with vaporizing energy control means, detection means adjacent said film substrate for continuously monitoring the electromagnetic radiation emanant from the coated film substrate after deposition for providing an electrical signal, the magnitude of said signal being functionally related to the resistivity of the coated film substrate, first and second comparison means coupled with said detection means for comparing said electrical signal (1) with a first predetermined reference level, and (2) with a second predetermined reference level, said first predetermined reference level corresponding to a narrower range of electromagnetic radiation percentage emanant from the coated substrate than said second predetermined reference level, each said comparison means providing a control signal when the magnitude of the electrical signal from the detection means deviates from a specific value related to its respective predetermined reference level, and means operated by the control signal from said first comparison means for varying an output signal applied to said vaporizing energy control means to compensate for long term drifts in said resistivity, and means operated by said second comparison means for affecting said output signal to compensate for short term changes in said resistivity whereby vaporizing energy is varied to achieve the required surface resistivity distribution of the deposit.

Claim 12

A control system for a vacuum deposition system for the maintenance of the required surface resistivity distribution of the deposit formed by vapor deposition of metal on a moving film substrate comprising means adapted to contain coating metal adjacent to the path of the film substrate, means for delivering vaporizing energy to said metal, means for supplying electric power to said means for delivering vaporizing energy, said means for supplying electric power being coupled with vaporizing energy control means, detection means adjacent said film substrate for continuously monitoring the electromagnetic radiation emanant from the coated film substrate after deposition for providing an electrical signal, the magnitude of said signal being functionally related to the resistivity of the coated film substrate, first and second comparison means coupled with said detection means for comparing said electrical signal (1) with a first predetermined reference level, and (2) with a second predetermined reference level, said first predetermined reference level corresponding to a narrower range of electromagnetic radiation percentage emanant from the coated substrate than said second predetermined reference level, each said comparison means providing a control signal when the magnitude of the electrical signal from the detection means deviates from a specific value related to its respective predetermined reference level, and means operated by the control signal from said first comparison means for varying an output signal applied to said vaporizing energy control means to compensate for long term drifts in said resistivity, and means operated by said second comparison means for affecting said output signal to compensate for short term changes in said resistivity whereby vaporizing energy is varied to achieve the required surface resistivity distribution of the deposit.

Claim 13

A control system as in claim 8 wherein said means operated by the control signal from said first comparison means comprises motor means coupled with potentiometer means, said potentiometer means being coupled to said vaporizing energy control means for supplying said output signal to said vaporizing energy control means, and said means operated by said second comparison means comprises controllable impedance means coupled with said potentiometer.

Claim 14

A control system as in claim 9 wherein said means for delivering vaporizing energy to said metal comprises an electron beam gun, and said electromagnetic radiation is infrared radiation.

Claim 15

A control system as in claim 8 wherein said first and second comparison means include electromechanical means providing conducting electrical isolation between said detection means and the means operated by the control signals from said first and second comparison means.