Paper feed system for photographic printer

In a photographic printer, a photosensitive paper web feed system comprising:

• a paper deck;
• feed idler roller means from which a photosensitive paper web is fed to the paper deck;
• take-up driven roller means for taking up the paper web from the paper deck;
• paper mask means for masking a portion of the paper web at the paper deck;
• feed metering idler roller means positioned between the feed idler roller means and the paper mask means over which the paper web is fed from the feed idler roller means to the paper deck, advancement of the paper web from the feed idler roller means across the paper deck to the take-up driven roller means, causing rotation of the feed metering idler roller means;
• paper feed sensing means for sensing the rotation of the feed metering idler roller means while permitting free rotation thereof and producing an electrical pulse for each increment of rotation of the feed metering idler roller means during a paper feed cycle;
• motor means for driving, during the paper feed cycle, only the take-up driven roller means to supply the only driving force by which the paper web is fed from the feed idler roller means, across the paper deck, and to the take-up driven roller means;
• paper feed length determining means for producing a digital electrical signal, prior to initiation of the paper feed cycle, indicative of the number of electrical pulses from the paper feed sensing means required to produce a desired paper feed length of the paper web during the paper feed cycle;
• means for providing a cycle initiate electrical signal for initiating a paper feed cycle;
• and
• control means for initiating operation of the motor means in response to the cycle initiate electrical signal to start the paper feed cycle and for controlling operation of the motor means during the paper feed cycle as a function of the digital electrical signal from the paper feed length determining means and the electrical pulses from the paper feed sensing means, the control means including electronic counter means for counting from an initial count to a final count in response to the electrical pulses from the paper feed sensing means, the electronic counter means providing control signals to the motor means which cause the motor means, and thus the paper feed cycle, to halt when the final count is attained, the number of electrical pulses from the paper feed sensing means required for the electrical counter means to count from the initial count to the final count being determined by the digital electrical signal from the paper feed length determining means.