CPC H04N 1/02835 (2013.01) [G02B 6/0068 (2013.01); G02B 6/0076 (2013.01); H04N 1/02805 (2013.01); H04N 1/02885 (2013.01)] | 10 Claims |
1. An image sensor lighting unit comprising:
at least one light guide extending in a main scanning direction and configured to emit light in a predetermined direction;
a first light source group facing a first end surface of at least two end surfaces of the at least one light guide in the main scanning direction; and
a second light source group facing a second end surface of the at least two end surfaces,
the first light source group including a first light source configured to emit light having a predetermined wavelength band,
the second light source group including a second light source configured to emit light having a same wavelength band as the light emitted from the first light source,
with an XY-coordinate system consisting of a Y-axis and an X-axis set with the at least one light guide viewed from the first end surface side in the main scanning direction, an X-coordinate of the first light source in a corresponding XY-coordinate system being equal in absolute value to an X-coordinate of the second light source in a corresponding XY-coordinate system,
the Y-axis set on an optical axis of emitted light and being positive in a traveling direction of the emitted light, and
the X-axis formed by rotating the Y-axis clockwise by 90° with a center of an end surface of the corresponding light guide in the main scanning direction taken as an axis of rotation.
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