A system for incorporating, in the production of a stream of images by an image transfer device upon a moving web, post-production operations upon the web at various locations, said system comprising:
- an image transfer device for applying images to a continuous web output therefrom, the image transfer device including means for generating electronic pulses as predetermined length increments of the web pass through the image transfer device;
- first means for counting the electronic pulses from the first means for generating;
- first means, responsive to the first means for counting, for indicating a page of the web having an image thereon based upon a predetermined number of pulses;
- a post-production device positioned downstream of the image transfer device and receiving the web output from the image transfer device, the post-production device performing a post-production process on the web received thereby;
- second means for generating electronic pulses as predetermined length increments of the web pass through the post-production device, the length increments of web passing through the post-production device being equal in length to the predetermined length increments passing through the image transfer device;
- second means for counting the electronic pulses from the second means for generating;
- second means, responsive to the second means for counting, for indicating a page of the web having an image thereon based upon a predetermined number of pulses;
- a shift register having a plurality of blocks for storing values therein, a number of blocks in the shift register equal to a number of pages on the web positioned between the image transfer device and the post-production device, the values in each of the blocks of the shift register corresponding to one of a plurality of specific post-production operations and the blocks being arranged so that the values shift therealong from an upstream end to a downstream end of the shift register as pages pass from the image transfer device to the post-production device;
- means from shifting the values in each of the blocks downstream by one block as each page passes through the post-production device;
- means for adding a block to the upstream end of the shift register when a page is output from the image transfer device before a page is input to the post-production device;
- means for removing a block from the upstream end of the shift register when a page is input to the post-production device and before a page is output from the image transfer device;
- and
- means for reading the value of the downstream block and for instructing the post-production device to perform the post-production process corresponding to the value in the downstream block on the web as the page corresponding to the downstream block is input into the post-production device.