LIGHT GUIDE, ILLUMINATING DEVICE HAVING THE LIGHT GUIDE, AND IMAGE READING DEVICE AND INFORMATION PROCESSING APPARATUS HAVING THE ILLUMINATING DEVICE

• US 20090284810A1
• Filed: 07/23/2009
• Published: 11/19/2009
• Est. Priority Date: 01/19/1993
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Itabashi, Satoshi, Takeda, Shinichi, Hamamoto, Osamu, Iso, Toshimitsu, Kawai, Tatsundo
• Application Number:
  US12/508,085
• Publication Number:
  US 20090284810A1
• Time in Patent Office: Days
• US Class Current: 358/475
• CPC Class Codes: G02B 2006/0098 for scanning
• CPC Class Codes: G02B 6/0001 specially adapted for lighting devices or systems lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00
• CPC Class Codes: G02B 6/0013 Means for improving the coupling-in of light from the light source into the light guide coupling light into light guides in general G02B6/42
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/10 of the optical waveguide type G02B6/02, G02B6/24 take precedence; devices or arrangements for the control of light by electric, magnetic, electro-magnetic or acoustic means G02F1/00; transferring the modulation of modulated light G02F2/00; optical logic elements G02F3/00; optical analogue/digital converters G02F7/00
• CPC Class Codes: G02B 6/42 Coupling light guides with opto-electronic elements
• CPC Class Codes: H04N 1/02815 Means for illuminating the original, not specific to a particular type of pick-up head
• CPC Class Codes: H04N 1/0282 Using a single or a few point light sources, e.g. a laser diode
• CPC Class Codes: H04N 1/02835 in combination with a light guide, e.g. optical fibre, glass plate light-guides per se G02B6/00
• CPC Class Codes: H04N 1/0284 in combination with a light integrating, concentrating or diffusing cavity
• CPC Class Codes: H04N 1/02885 Means for compensating spatially uneven illumination, e.g. an aperture arrangement
• CPC Class Codes: H04N 1/0289 Light diffusing elements, e.g. plates or filters optical diffusing elements per se G02B5/02
• CPC Class Codes: H04N 1/03 with photodetectors arranged in a substantially linear array
• CPC Class Codes: H04N 1/0313 Direct contact pick-up heads, i.e. heads having no array of elements to project the scanned image elements onto the photodectors
• CPC Class Codes: H04N 1/0316 : illuminating the scanned image elements through the plane of the photodetector, e.g. back-light illumination
• CPC Class Codes: H04N 1/0318 : Integral pick-up heads, i.e. self-contained heads whose basic elements are a light-source, a lens array and a photodetector array which are supported by a single-piece frame
• CPC Class Codes: H04N 2201/03112 : Light source
• CPC Class Codes: H04N 2201/03125 : Light guide upstream of the scanned picture elements
• CPC Class Codes: H04N 2201/03129 : Transparent cover or transparent document support mounted on the head
• CPC Class Codes: H04N 2201/03141 : Photodetector lens
• CPC Class Codes: H04N 2201/03145 : Photodetector

Abstract

In an illumination device, a light guide is adapted to emit the light from a face thereof and is provided with an area, on a face opposite to the light emitting face, for diffusing and/or reflecting the light introduced into the light guide from an end face thereof or is provided with uneven light emitting characteristics along the longitudinal direction of the light guide, and the center of the light source positioned at the end of the light guide is placed at a position aberrated from the normal line to the area, whereby attained are compactness, a low cost, a low electric power consumption, a high efficiency of utilization of the light emitted by the light source, and excellent and uniform illumination characteristics. An image reading device and an information processing apparatus can also be equipped with the above-mentioned illumination device.

Claims

1. An information processing apparatus comprising:

an illumination device provided with a longitudinal light guide, for guiding light introduced from a light source and for emitting the light along a longitudinal side thereof, having a longitudinal reflection member arranged along said light guide for reflecting the light from said light source;

a photoelectric converting device having a plurality of photoelectric conversion elements for reading an image illuminated by said illumination device and for outputting an image signal; and

a processor for processing the image signal output from said photoelectric converting device.

2. An information processing apparatus comprising:

an illumination device provided with a longitudinal light guide, for guiding light introduced from a plurality of light sources and for emitting the light along a longitudinal side thereof, having a longitudinal reflection member arranged along said light guide for reflecting the light from said plurality of light sources;

a photoelectric converting device having a plurality of photoelectric conversion elements for reading an image illuminated by said illumination device and for outputting an image signal; and

a processor for processing the image signal output from said photoelectric converting device.