GB1313015A - Copying apparatus - Google Patents

Abstract

1313015 Photographic projection apparatus XEROX CORP 21 Sept 1970 [22 Sept 1969] 44852/70 Headings G2H G2A and G2J In a photographic projection apparatus, as described, a xerographic copier, for imaging a stationary original, e.g. a book 68, onto a moving image receiving surface 10 utilizing a scanning lens 18 and a scanning light source 15, an original support platen 14 defines a corner with a support member 63 of the apparatus and the light source is substantially opaque, only having a single light transmitting aperture 72 arranged to direct a band of illumination forward of said lamp 15 towards said corner as the lamp is moved to scan the original for copying. A platen cover (not shown) is provided. The lamp is held by a carriage 71 movably supported between a drive shaft 58 having a helical groove (79) Fig. 6, (not shown) therein and a support rod 59. As the shaft 58 is rotated by the main drive of the apparatus in synchronism with the drive to a drum 11 carrying the surface 10, a pin (78) Fig. 1, (not shown) following the groove (79) causes the carriage to move. The carriage first rapidly accelerates to the scanning velocity, then moves linearly across the platen until, at the end of the scanning motion, it is rapidly decelerated to zero velocity. A faster return motion is imparted by rotation of the groove (79). A counterweight (88) is provided so as to overcome the moment of the carriage 71 about the shaft 58. The carriage also trips limit switches (74, 73) to energize and de-energize the lamp at the beginning and end of a scanning movement. More than one lamp may be provided Fig.10, (not shown), the apertures (72) of each directing light onto the same position of the platen. The scanning apparatus so described can look into corners or other inaccessible areas. An optical system receiving reflected light image from the scanned original comprises the horizontally adjustable scanning lens 18, two mirrors 19, 20 both of which are adjustably supported, and a slotted light shield 110 defining an exposure aperture 111. As shown, the system is arranged to give non-magnified images, but the lens may be positioned to give magnified images. The lens movement is synchronized with that of charged drum 11 Fig.3, (not shown), thus when the drum stops, the lens and light also stop. This means that the area of the drum adjacent the aperture 111 maybe continually exposed to ambient light, thereby affecting the photo-conductive properties of the drum. Accordingly, an automatic shutter (140) Fig. 4, (not shown) is provided, which shutter moves to close the aperture 111 when the drum surface is not in motion.