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US 6,607,129 B1Granted
Optical scanner and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorManabu Kato
Life of this patent
Estimating the term…
Abstract
An optical scanner to be used for an image forming apparatus such as a digital copying machine includes a light source, such as a semiconductor laser, for emitting a light beam; a deflection element, such as a rotary polygon mirror, for deflecting the emitted light beam; and a scanning optical system for focusing the deflected light beam on a surface to be scanned, typically a photosensitive drum surface. The scanning optical system includes at least first and second optical elements as well as a reflector mirror arranged on the optical path between the first optical element and the second optical element for reflecting the light beam coming from the former and leading the light beam to the latter so that any displacement of the scanning spot in the sub-scanning direction may effectively be eliminated.
Claims20
An optical scanner comprising:
- a light source;
- a deflection element for deflecting a light beam emitted from said light source;
- a scanning optical system including at least first and second optical elements and adapted to focus the light beam deflected by said deflection element onto a surface to be scanned;
- a reflector mirror disposed in an optical path between said first optical element and said second optical element to reflect the light beam from said first optical element to said second optical element;
- and
- an incidence optical system adapted to focus the light beam emitted from said light source onto a deflecting surface of said deflection element and to produce a linear image extending in a main-scanning direction.
3 more elements
An optical scanner comprising:
- a light source;
- a deflection element for deflecting a light beam emitted from said light source;
- a scanning optical system including at least first and second optical elements and adapted to focus the light beam deflected by said deflection element onto a surface to be scanned;
- and
- a reflector mirror disposed in an optical path between said first optical element and said second optical element to reflect the light beam from said first optical element to said second optical element,
- wherein a front focal point of said first optical element is located close to a deflecting surface of said deflection element and a rear focal point of said second optical element is located close to the surface to be scanned in a sub-scanning direction.
3 more elements
An optical scanner comprising:
- a light source;
- a deflection element for deflecting a light beam emitted from said light source;
- a scanning optical system including at least first and second optical elements and adapted to focus the light beam deflected by said deflection element onto a surface to be scanned;
- and
- a reflector mirror disposed in an optical path between said first optical element and said second optical element to reflect the light beam from said first optical element to said second optical element,
- wherein, if a rear focal length of said second optical element in a sub-scanning direction is f2S, and a distance between a rear principal plane of said second optical element in the sub-scanning direction and a surface to be scanned is h2s, f25 and h2S satisfy the following relationships:
- 0.5<h2s/f2s<2.0.
4 more elements
An optical scanner comprising:
- a light source;
- a deflection element for deflecting a light beam emitted from said light source;
- a scanning optical system including at least first and second optical elements and adapted to focus the light beam deflected by said deflection element onto a surface to be scanned;
- and
- a reflector mirror disposed in an optical path between said first optical element and said second optical element to reflect the light beam from said first optical element to said second optical element,
- wherein said scanning optical system establishes an optically conjugated relationship between a deflecting surface of said deflection element and the surface to be scanned in a sub-scanning direction.
3 more elements
An optical scanner comprising:
- a light source;
- a deflection element for deflecting a light beam emitted from said light source;
- a scanning optical system including at least first and second optical elements and adapted to focus the light beam deflected by said deflection element onto a surface to be scanned;
- and
- a reflector mirror disposed in an optical path between said first optical element and said second optical element to reflect the light beam from said first optical element to said second optical element,
- wherein said second optical element includes a diffraction grating provided on at least a surface thereof.
3 more elements
An optical scanner comprising:
- a light source;
- a deflection element for deflecting a light beam emitted from said light source;
- a scanning optical system including at least first and second optical elements and adapted to focus the light beam deflected by said deflection element onto a surface to be scanned;
- and
- a reflector mirror disposed in an optical path between said first optical element and said second optical element to reflect the light beam from said first optical element to said second optical element,
- wherein said reflector mirror is supported so as to make controllable a posture of said reflector mirror.
3 more elements
An optical scanner comprising:
- a light source;
- a deflection element for deflecting a light beam emitted from said light source;
- a scanning optical system including at least first and second optical elements and adapted to focus the light beam deflected by said deflection element onto a surface to be scanned;
- and
- a reflector mirror disposed in an optical path between said first optical element and said second optical element to reflect the light beam from said first optical element to said second optical element,
- wherein said light source includes a multi-beam semiconductor laser adapted to emit a plurality of laser beams.
3 more elements
Dependencies are inferred from the claim text.