Light guide, light source device, and image reading device

• US 9,946,009 B2
• Filed: 08/30/2016
• Issued: 04/17/2018
• Est. Priority Date: 12/20/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Fujiuchi, Akiko, Arimoto, Hironobu, Matsuzawa, Taku
• Primary Examiner(s): Lee, Cheukfan
• Application Number:
  US15/251,219
• Publication Number:
  US 20160370532A1
• Time in Patent Office: 595 Days
• Field of Search: None
• CPC Class Codes: G02B 19/0047 for use with a light source G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 3/02 with non-spherical faces G02B3/10 takes precedence
• CPC Class Codes: G02B 6/0045 by shaping at least a portion of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G03B 15/03 Combinations of cameras with lighting apparatus; Flash units
• CPC Class Codes: H04N 1/02825 in combination with at least one reflector which is fixed in relation to the light source H04N1/02835 and H04N1/0284 take precedence
• 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 2201/0081 Image reader H04N2201/0091 - H04N2201/0094 take precedence

Abstract

A light guide includes a first exit portion emitting first exiting light, a second exit portion emitting second exiting light in a different direction than the first exiting light, and a reflecting portion reflecting light entering the light guide to each of the first and second exit portions. The first and second exit portions respectively have first and second curved surfaces each having a convex cross section perpendicular to the long axis direction. The second exit portion is connected to the first exit portion in the direction perpendicular to the long axis direction. The reflecting portion is provided, in a plane facing the first exit portion and the second exit portion, at a position shifted in the direction perpendicular to the long axis direction from a position where a normal to the plane passes through a connection portion between the first and second exit portions.

Claims

1. A light guide extending in a long axis direction and having an end in the long axis direction from which light enters the light guide, the light guide comprising:

a first exit portion having a first curved surface having a convex cross section perpendicular to the long axis direction, and emitting first exiting light;

a second exit portion having a second curved surface having a convex cross section perpendicular to the long axis direction, being connected to the first exit portion in a direction perpendicular to the long axis direction, and emitting second exiting light in a direction different from a direction of the first exiting light;

a first reflecting portion disposed in a first plane portion facing the first exit portion;

a second reflecting portion disposed in a second plane portion facing the second exit portion; and

at least one recess of;

a recess extending in the long axis direction and disposed between the first exit portion and the second reflecting portion; and

a recess extending in the long axis direction and disposed between the second exit portion and the first reflecting portion,

the at least one recess being formed by planes extending in the long axis direction and intersecting each other,

the at least one recess being formed by a plane parallel to an optical axis of the first exiting light and by a plane intersecting the plane parallel to the optical axis of the first exiting light.

2. The light guide according to claim 1, wherein the intersection angle between the planes forming the at least one recess is 90 degrees.

3. The light guide according to claim 1, wherein the intersection angle between the planes forming the at least one recess is an obtuse angle.

4. The light guide according to claim 1, further comprising a light blocking member disposed in a corresponding one of the at least one recess.

5. A light guide extending in a long axis direction and having an end in the long axis direction from which light enters the light guide, the light guide comprising:

a first exit portion having a first curved surface having a convex cross section perpendicular to the long axis direction, and emitting first exiting light;

a second exit portion having a second curved surface having a convex cross section perpendicular to the long axis direction, being connected to the first exit portion in a direction perpendicular to the long axis direction, and emitting second exiting light in a direction different from a direction of the first exiting light;

a first reflecting portion disposed in a first plane portion facing the first exit portion;

a second reflecting portion disposed in a second plane portion facing the second exit portion; and

at least one recess of;

a recess extending in the long axis direction and disposed between the first exit portion and the second reflecting portion; and

a recess extending in the long axis direction and disposed between the second exit portion and the first reflecting portion,

the at least one recess being formed by planes extending in the long axis direction and intersecting each other,

the recess disposed between the first exit portion and the second reflecting portion being formed by a plane parallel to an optical axis of the first exiting light and by a plane intersecting the plane parallel to the optical axis of the first exiting light, and

the recess disposed between the second exit portion and the first reflecting portion being formed by a plane parallel to an optical axis of the second exiting light and by a plane intersecting the plane parallel to the optical axis of the second exiting light.

6. The light guide according to claim 5, wherein the intersection angle between the planes forming the at least one recess is 90 degrees.

7. The light guide according to claim 5 wherein the intersection angle between the planes forming the at least one recess is an obtuse angle.

8. The light guide according to claim 5, further comprising a light blocking member disposed in a corresponding one of the at least one recess.