Exposure system

An exposure system for light sensitive materials comprising

• a vacuum frame to hold the light sensitive materials,
• a light source to provide light to expose said light sensitive materials, and
• a filter housing interposed between said light source and said vacuum frame, said filter housing having at least three filters selectively positionable between said light source and light sensitive materials in said vacuum frame,
• including means to position said filters between said light and said vacuum frame singularly or in multiples and
• opposed channels facing one another across an open area wherein said positioning means for each filter includes a frame for said filter having opposed sides and mounted for reciprocation in said opposed channels of said housing and a cable connected to either side of said frame and passing through said housing to be driven to position said frame and a motor driving a sheave around which the cable is trained to drive said frame and its filter into or out of position by actuation of said motor, said cable and sheave being selected of materials and configured so that said cable can slip around said sheave to prevent injury to things in the way of a driven filter or to permit the movement of said filter by hand without actuation of said motor and including a spring in said cable to limit the tension on the cable, and limit switches on said housing actuable by the positioning of the filter either in or out of position to stop the actuation of said motor, and further comprising a memory unit to recall a particular arrangement of filter positions and a program actuation means to actuate said motor to position said filters in accordance with a recalled arrangement.

An exposure system for light sensitive materials comprising

• a vacuum frame to hold the light sensitive materials
• a light source to provide light to expose said light sensitive materials
• a filter housing interposed between said light source and said vacuum frame, said filter housing
• having at least three filters selectively positionable between said light source and light sensitive materials in said vacuum frame,
• including means to position said filters between said light and said vacuum frame singularly or in multiples including a plurality of selectively positionable frames, at least one of said filters being removably mountable in at least one of said frames.

An exposure light for light sensitive materials, particularly for materials requiring a particular spectral distribution of incident light, comprising

• an electrically powered light source,
• an electrical energy supply to said light source,
• a voltage drop sampling means across said light source,
• a blower arranged with respect to said light source to blow cooling air towards said light source, and
• a speed control device for said blower to control the speed of said blower in response to sampled voltages to maintain the temperature of said light source at a desired level wherein said electrically powered light source has a length and two ends and said blower provides air at said ends of said electrically powered light source at an acute angle to the light source length, to form a helical airflow around said light source.

An exposure system for light sensitive materials, particularly for materials requiring a particular spectral distribution of incident light, comprising

• an electrical light source having an operating temperature of at least 900 degrees celsius, two ends and a mid-portion,
• a control unit to control operating parameters of a plurality of subsystem units of the exposure system such as exposure level, chainable control lines from said control unit to the subsystem units including a plurality of physically equivalent, but electrically unique pin socket outputs each having a plurality of electrical leads on said control unit,physically equivalent, but electrically unique pin sockets each having a plurality of electrical leads on the subsystem units, and a plurality of cables having physically and electrically identical terminations such that any of said cables may be used to connect a pin socket of said control unit to a pin socket of a subsystem unit,
• said control unit including an electronic memory storage means and means responsive to signals stored in said electronic memory storage means to control said subsystem units,
• a keyboard input to said memory storage means of variables to be stored and including function keys to select the variable to be assigned a value and numeric keys to assign a numeric value to a selected numeric variable,
• a power supply to said light source, said power supply having the capacity to supply several kilowatts of electrical power to said light source and having the capacity to supply reduced power to said light source, reduced by increments of about one hundred watts and having a power consumption monitor to continuously monitor the power consumed in said light source and to modify the power supplied to said light source to compensate for any fluctuations in power consumption by said light source to maintain the power consumption at a constant level and being connected to said light source through a switch, a voltage drop sampling means across said electrical light source,
• a housing supporting said electrically powered light source and having air exhaust openings proximate said mid-portion of said light source and having an open face through which light from said light source passes when said shutter is open and a removable pane covering said open face with an indicator to indicate the presence of said pane covering said open face,
• a metal shutter in said housing having a black ceramic surface adjacent the light source to selectively expose light sensitive materials to light from said high temperature light source,
• a blower arranged with respect to said light source in said housing to blow cooling air towards said ends of said electrically powered light source at an acute angle to the light source length, to form a helical airflow around said light source and out said air exhaust openings, a speed control for said blower to control the speed of said blower in response to sampled voltages to maintain the voltage and therefore the temperature of said light source at a desired level, said control means being adapted to control said light source and said shutter and including a timer and being responsive to said switch to hold said shutter closed for a period of time after said switch is opened long enough to permit cooling of said light source and to open said shutter after expiration of the period and wherein said control means actuates said blower during the period after said switch is opened to hasten the cooling of said light source and including means responsive to said indicator and said switch to close said shutter when said indicator senses removal of said pane while power is being supplied to said light source to prevent access to said light source while power is being supplied to said light source.

A method of controlling the spectral output of a high temperature electrically powered light source having two ends and a mid-portion for an exposure system comprising

• supporting the electrically powered light source in a housing having air exhaust openings proximate the mid-portion of the light source,
• supplying electrical energy to the light source,
• sampling the voltage drop across the light source,
• blowing air towards the ends of the electrically powered light source at an acute angle to the light source length, to form a helical airflow around the light source and out the air exhaust openings, and
• controlling the rate of air blowing towards the light source in response to sampled voltages to maintain the voltage and therefore the temperature and spectral output of the light source at a desired level.

A method of controlling an exposure system for light sensitive materials comprising the steps of

• a) providing
• i) an electronic memory and means responsive to signals stored in the electronic memory to control variables,
• ii) a keyboard input to the electronic memory of variables to be stored and including function keys to select the variable to be assigned a value and numeric keys to assign a numeric value to a selected numeric variable, and
• iii) a plurality of signal lights connected to the electronic memory and arranged to display during data input to the electronic memory which variable is next to be assigned a value or selected,
• b) recording in the electronic memory values for a plurality of the variables by pressing function keys corresponding to a function to be remembered as prompted by the signal light corresponding to the function and pressing a numeric key corresponding to a value to be assigned to a function, and
• c) actuating the exposure system so that the functions and values recorded in the electronic memory are used to control the corresponding functioning portion of the exposure system.