Graphic forms overlay apparatus

Abstract

A graphic forms overlay apparatus to be used with non-impact printers requiring the use of a movable light sensitive medium such as laser printers is disclosed. Laser printers use a sweeping laser beam and a movable light sensitive medium to image data from a data processing source for printing. A graphic forms pattern is overlayed on the data imaged on the light sensitive medium for simultaneous printing of the data and pattern. To accomplish this a negative of the pattern is mounted on a hollow rotatable forms drum, and inside the drum a fluorescent tube is fixedly mounted for illuminating the negative. A linear portion of the light image of the negative formed thereby is reflected by an optical system of lenses and mirrors onto adjacent linear portions of the light sensitive medium being swept by the laser beam for imaging of data. Synchronism between rotation of the forms drum and information being written on the movable light sensitive medium is provided by logic circuitry connected between the printer and a stepping motor which is coupled to the forms drum for rotation of the forms drum. A top of page signal from the printer cooperates with the logic circuitry to start synchronous rotation of the forms drum. An alignment signal from an alignment means within the overlay apparatus cooperates with the logic circuitry to stop rotation of the forms drum in an initial position ready for the next top of page signal. Adjustable counter circuitry provides a means for externally varying the rotational speed of the forms drum.