Lighting apparatus and image reading apparatus

Patent metadata

Field	Value
Publication number	US-9894233-B2
Application number	US-201515126516-A
Country	US
Kind code	B2
Filing date	Mar 3, 2015
Priority date	Mar 17, 2014
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A lighting apparatus includes a first illumination portion and a second illumination portion. The first illumination portion and the second illumination portion respectively include a bar-like light guide whose shape of an end face of an end portion includes a part of a circle, an ellipse or a parabola, and light source elements that are provided to face the end face of the end portion of the light guide. In the light guide of the second illumination portion, light enters a determined range in which a focus of the shape of the end face of the end portion of the light guide is included. In the light guide of the first illumination portion, light enters a range that is not the determined range in which the focus of the shape of the end face of the light guide is included.

First claim

The invention claimed is:

1. A lighting apparatus comprising a first illumination portion and a second illumination portion, each including a bar-like light guide that includes an end face of a peripheral shape that includes at least a part of a circle, an ellipse or a parabola, and light source elements provided to face an end face of the light guide,
wherein light enters the light guide of the second illumination portion in a determined range in which a focus of the circle, the ellipse or the parabola included in the shape of the end face of the light guide is included, and
wherein in the first illumination portion, the light source elements are disposed in a range that is not the determined range in which the focus of the shape of the end face of the light guide is included and light enters the light guide of the first illumination portion in the range that is not the determined range in which the focus of the circle, the ellipse or the parabola included in the shape of the end face of the light guide is included.

2. The lighting apparatus according to claim 1 , wherein
in the second illumination portion, the light source elements are disposed in the determined range in which the focus of the shape of the end face of the light guide is included.

3. An image scanning apparatus comprising:
the lighting apparatus according to claim 2 to irradiate light onto a scanning object and extends in a main scanning direction;
a rod lens array to image light irradiated from the lighting apparatus and reflected by the scanning object or the light transmitted through the scanning object; and
a photoelectric conversion element array to convert light imaged by the rod lens array into an electrical signal, wherein
the first illumination portion irradiates a first reading area with the light that is inclined at a determined angle from a normal direction of the scanning object, and
the second illumination portion irradiates a second reading area away from the first reading area in a sub-scanning direction with light in the normal direction of the scanning object.

4. The lighting apparatus according to claim 1 , wherein
the first illumination portion and the second illumination portion further comprise light blocking members disposed between the light guide and the light source elements,
in the first illumination portion, the light entering the determined range, in which the focus of the shape of the end face of the light guide is included, is blocked by the light blocking member, and
in the second illumination portion, the light entering the range that is not the determined range, in which the focus of the shape of the end face of the light guide is included, is blocked by the light blocking member.

5. An image scanning apparatus comprising:
the lighting apparatus according to claim 4 to irradiate light onto a scanning object and extends in a main scanning direction;
a rod lens array to image light irradiated from the lighting apparatus and reflected by the scanning object or the light transmitted through the scanning object; and
a photoelectric conversion element array to convert light imaged by the rod lens array into an electrical signal, wherein
the first illumination portion irradiates a first reading area with the light that is inclined at a determined angle from a normal direction of the scanning object, and
the second illumination portion irradiates a second reading area away from the first reading area in a sub-scanning direction with light in the normal direction of the scanning object.

6. The lighting apparatus according to claim 1 , wherein
in the first illumination portion, a light blocking area is provided in the determined range in which the focus of the shape of an end face of a light incidence plane of the light guide is included, and
in the second illumination portion, a light blocking area is provided in the range that is not the determined range in which the focus of the shape of the end face of the light incidence plane of the light guide is included.

7. An image scanning apparatus comprising:
the lighting apparatus according to claim 6 to irradiate light onto a scanning object and extends in a main scanning direction;
a rod lens array to image light irradiated from the lighting apparatus and reflected by the scanning object or the light transmitted through the scanning object; and
a photoelectric conversion element array to convert light imaged by the rod lens array into an electrical signal, wherein
the first illumination portion irradiates a first reading area with the light that is inclined at a determined angle from a normal direction of the scanning object, and
the second illumination portion irradiates a second reading area away from the first reading area in a sub-scanning direction with light in the normal direction of the scanning object.

8. An image scanning apparatus comprising:
the lighting apparatus according to claim 1 to irradiate light onto a scanning object and extends in a main scanning direction;
a rod lens array to image light irradiated from the lighting apparatus and reflected by the scanning object or the light transmitted through the scanning object; and
a photoelectric conversion element array to convert light imaged by the rod lens array into an electrical signal, wherein
the first illumination portion irradiates a first reading area with the light that is inclined at a determined angle from a normal direction of the scanning object, and
the second illumination portion irradiates a second reading area away from the first reading area in a sub-scanning direction with light in the normal direction of the scanning object.

Assignees

• Mitsubishi Electric Corp

Inventors

• Matsuzawa Taku
• Fujiuchi Akiko
• Shoji Toshiaki

Classifications

• G03B27/72

  Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus · CPC title

• G02B6/0006

  Coupling light into the fibre (in general G02B6/4298) · CPC title

• H04N1/02885

  Means for compensating spatially uneven illumination, e.g. an aperture arrangement · CPC title

• G02B13/0095

  Relay lenses or rod lenses (in instruments for viewing the inside of hollow bodies G02B23/2446) · CPC title

• H04N2201/0081

  Image reader (H04N2201/0091 - H04N2201/0094 take precedence) · CPC title