Illumination means for use in photocopying machine

Abstract

An illumination means for use in association with a SELFOC image transmitter in a photocopying machine. The illumination means comprises at least one light generator in the form of a tubular fluorescent lamp or similar means emitting light through a slit disposed parallel to the longitudinal axis thereof, and an associated light-guide which is made of glass, plastic, or other material having a high refractive index, is generally equal in length to the light-generator, has a generally trapezoidal cross-section, and directs light emitted by the light-generator into an illumination slot or shutter means provided in or below a document rest for illumination of successive portions of a document to be copied, the light-guide broad base and narrow base being proximate to, in line with, and generally equal in width to the light-generator slit and the document rest slot, respectively. Preferably the sides of the light-guide are coated with a reflective film, and a certain area of the central portion of the base thereof may be coated with a reflective patch to eliminate extra light, and so counteract the characteristic tendency of a tubular lamp to produce a greater quantity of light at the centre. The means of the invenion presents the advantages that there is an even distribution of light for illumination of documents to be copied, that there is less consumption of electricity and less generation of heat, and that the means consists of unitary elements which may be easily assembled.

Dependencies are inferred from the claim text.