Optical illumination device for use in a copying apparatus

• US 4,827,314 A
• Filed: 02/26/1988
• Issued: 05/02/1989
• Est. Priority Date: 03/03/1987
• Status: Expired due to Fees

• Current Assignee: Minolta Camera Kabushiki Kaisha
• Original Assignee: Minolta Camera Kabushiki Kaisha
• Inventors: Fujiwara, Takao
• Primary Examiner(s): Braun, Fred L.
• Application Number:
  US07/160,636
• Time in Patent Office: 431 Days
• Field of Search: 355/8, 355/14 E, 355/68, 355/69, 355/1
• US Class Current: 355/68
• CPC Class Codes: G03B 27/542 for copying cameras, reflex exposure lighting

Abstract

An optical illumination device for a copying apparatus which includes a light source, a series of reflectors, and a light detecting member for detecting the amount of light reflected off of the original document to control the intensity of the light source. The series of reflectors includes two reflectors on the opposite side of the optical path from the light source which are integrally formed to provide an L-shape configuration in cross section. One of the integrally formed reflectors reflects the light from the document onto the light detecting member.

Claims

1. An optical illumination device for use in a copying apparatus of the type wherein an object is illuminated and projected onto a photoconductive member by changing a relative position of said object and said photoconductive member, said device comprising:

a light source;

a first reflector conducting light from said light source to said object;

a second reflector positioned opposite said light source for conducting light from said light source to said object such that the illumination of said object passes through an optical path from said object to said photoconductive member;

a light detection element provided opposite said light source with respect to said path;

a third reflector conducting light reflected from said object to said light detection element;

illumination control means for controlling illumination of said light source in accordance with the amount of light received by said light detection element,

wherein said third reflector reflects light from the next portion of said object to be projected immediately thereafter,

and said second and third reflectors formed integrally to provide substantially an L-shape in its cross section.

2. The optical illumination device as claimed in claim 1, further comprising a support member supporting as an integrated unit said light source, said first reflector, said second reflector and said third reflector.

3. The optical illumination device for use in a copying apparatus of the type wherein an original document is illuminated and an image thereof is projected to a photoconductive member, said device comprising:

a light source;

a first reflector conducting light from said light source to said document;

a second reflector conducting light to said document and positioned opposite said light source with respect to an optical path from said document to said photoconductive member;

a light detection element provided opposite said light source with respect to said path;

a third reflector conducting light reflected from said document to said light detection element;

illumination control means for controlling illumination of said light source in accordance with the amount of light received by said light detection element;

a document platen for mounting said original document, said platen movable over said light source,

wherein said third reflector reflects light from the forward portion of said document relative to said path in a direction of movement of said document platen,

and said second and third reflectors formed integrally to provide substantially an L-shape in its cross section.

4. The optical illumination device as claimed in claim 3, further comprising a support member supporting as an integrated unit said light source, said first reflector, said second reflector and said third reflector.

5. An optical illumination device for use in a copying apparatus of the type wherein an object is illuminated and projected onto a photoconductive member by changing a relative position of said object and said photoconductive member, said device comprising:

a light source;

a first reflector conducting light from said light source to said object;

a second reflector conducting light to said object and positioned opposite said light source through an optical path from said object to said photoconductive member;

a light detection element provided opposite said light source through said path;

a third reflector conducting light reflected from said object to said light detection element;

illumination control means for controlling illumination of said light source in accordance with the amount of light received by said light detection element;

an object platen for mounting said object, said platen movable over said light source,

wherein said third reflector reflects light from the forward portion of said object relative to said device in a direction of movement of said object platen, and said second and third reflectors are formed integrally to provide substantially an L-shape in its cross section.

6. The optical illumination device as claimed in claim 5, further comprising a support member supporting as an integrated unit said light source, said first reflector, said second reflector and said third reflector.