GB1496336A - Colour copying apparatus - Google Patents

Abstract

1496336 Control of copying apparatus CANON KK 13 Dec 1974 [13 Dec 1973 19 Dec 1973 (2) 20 Dec 1973 (2)] 54004/74 Heading B6C Colour copying apparatus comprises a movable electrostatically charged photosensitive medium, exposure means for projecting an original image on to said medium to form electrostatic latent images thereon, filter means including a predetermined number of colour resolving filter units selectively movable on to the projection path of the exposure means so that latent images having colour components of the original image are sequentially formed on the medium, and program control means to cause said exposure means and filter means to co-operate together. As shown, light from an original on a carriage 1 is projected on to a rotatable photoconductive drum 14 by scanning lamps 3 and mirrors 4, 5, a lens system 6 and fixed mirrors 8, 9, the light passing through a selected filter 7a of red, green, blue and neutral density filters of a rotatable filter means 7, the latent image being developed by a corresponding developing unit of units 15a-15d having cyan, magenta, yellow and black toners. A transfer medium of a selected size is fed from a cassette 40 by rolls 36, 35, 32-33, 31 and a guide 41 into contact with a rotatable transfer roll 24 to which it is electrostatically attracted and is urged against the charged dust image on drum 14 which image is thereby transferred to the medium P. Image formation on drum 14 and image transfer on to medium P are repeated for each different colour filter. The transfer medium is then fed to a heat fixing device 48. Transfer roll 24 and drum 14 are then cleared by devices 30, 51. The control means may cause the length to be scanned to vary with the size of transfer medium. The apparatus may be used for monochromatic reproduction. Details of the drives and control circuits of the various parts are disclosed.