Abstract: A method is described for exposing both sides of a light sensitive sheet such as a printed circuit board panel according to imaging data. The method uses a device that has an optical system for scanning the sensitive sheet by one or more beams. The optical system scans both sides with the scan lines on one side mutually positioned with respect to the scan lines on the other side. According to one implementation, the optical system includes two optical scanning units driven by a single source, with a switch alternating the beam from the source to one then the other optical scanning unit.

Abstract: A device is described for exposing both sides of a light sensitive sheet such as a printed circuit board panel according to imaging data. The device comprises an optical system for scanning the sensitive sheet by one or more beams. The optical system scans both sides with the scan lines on one side mutually positioned with respect to the scan lines on the other side. According to one implementation, the optical system includes two optical scanning units driven by a single source, with a switch alternating the beam from the source to one then the other optical scanning unit.

Abstract: A device is described for exposing both sides of a light sensitive sheet such as a printed circuit board panel according to imaging data. The device comprises an optical system for scanning the sensitive sheet by one or more beams. The optical system scans both sides with the scan lines on one side mutually positioned with respect to the scan lines on the other side. According to one implementation, the optical system includes two optical scanning units driven by a single source, with a switch alternating the beam from the source to one then the other optical scanning unit.

Abstract: A method and apparatus for use in improving the accuracy of scanning systems is disclosed and claimed. Systems such as internal drum photoplotters include a raster scanner responsive to control signals for advancing relative to a substrate an optical beam across a substrate surface in a first direction forming a scan line of pixels and for cooperatively advancing relative to the substrate the optical beam in a second direction substantially perpendicular to the first direction. The clock signal which is provided to a spinner to advance the optical beam across the scan line is independent from the pixel clock signal which is provided to control the generation of pixels. There is a memory for storing error compensation signals indicative of compensation needed to remove deviations of the separation between adjacent pixels in said scan line from preferred values thereof.