Browse Prior Art Database

Copier Illumination Device

IP.com Disclosure Number: IPCOM000089664D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Abbott, TD: AUTHOR [+3]

Abstract

An illumination system for a copier employs a multi-segment mask whose position is manually adjustable, during copier manufacture, to compensate for illumination parts tolerance variations.

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Copier Illumination Device

An illumination system for a copier employs a multi-segment mask whose position is manually adjustable, during copier manufacture, to compensate for illumination parts tolerance variations.

The illumination system of the copier machine includes a stationary, point light source 11, whose light rays are reflected from a stationary paraboloid surface 13 onto a scanning parabolic reflector 15. Reflector 15 moves in the scan direction shown by arrow 16. Light source 11 is located at the focus of paraboloid surface 13, causing the surface's reflected rays 17 to be parallel to one another. The parallel rays striking parabolic reflector 15 are reflected to the line-like focus thereof located on stationary original-document plane 19. The light rays 21 form a line of light 23 which scans an original document (not shown) in direction 16, as the parabolic reflector 15 moves. Light reflected from document plane 19 passes through lens 25 and is focused thereby onto a photoreceptive surface (not shown). This optical system is described in U.S. Patent 3,758,774.

Multi-segment, black mask 27 blocks some of the light rays 17 between paraboloid surface 13 and parabolic reflector 15, thereby causing more light to be reflected from the ends of parabolic reflector 15 than from the center thereof. The extra intensity at the edges of the line of light 23 compensates for the light falloff characteristics of the copier's lens 25.

Mask 27 may be positioned immedi...