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US 6,724,414 B2Granted
Imaging device array, optical writing unit and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorsKoji Masuda, Masahiro Itoh
Life of this patent
Estimating the term…
Abstract
An imaging device array of the present invention effectively reduces the influence of ghost light and flare light. An optical writing unit using the imaging device array and an image forming apparatus using the optical writing unit are also disclosed.
Claims28
An imaging device array comprising:
- a plurality of unit imaging devices each comprising a lens portion made up of a first lens surface to which a light beam for imaging is incident and a second lens surface from which said light beam is output, and a roof prism portion for reflecting said light beam incident via said first lens surface toward said second lens surface, said plurality of unit imaging devices being arranged integrally with each other such that first lens surfaces, second lens surfaces and roof prism portions each are arranged in a respective array;
- and
- light attenuating means each intervening between nearby lens portions for attenuating light propagating between said nearby lens portions;
- wherein said light attenuating means has an attenuation ratio α smaller than 0.25.
1 more element
An optical writing unit comprising:
- a light emitting portion array comprising a plurality of fine light emitting portions arranged in an array;
- and
- an imaging device array comprising:
- a plurality of unit imaging devices each comprising a lens portion made up of a first lens surface to which a light beam for imaging is incident and a second lens surface from which said light beam is output, and a roof prism portion for reflecting said light beam incident via said first lens surface toward said second lens surface, said plurality of unit imaging devices being arranged integrally with each other such that first lens surfaces, second lens surfaces and roof prism portions each are arranged in a respective array;
- and
- light attenuating means each intervening between nearby lens portions for attenuating light propagating between said nearby lens portions;
- wherein said light attenuating means has an attenuation ratio α smaller than 0.25.
4 more elements
An image forming apparatus comprising an optical writing unit for writing an image on a photoconductive element to thereby form an image, wherein said optical writing unit comprises:
- a light emitting portion array comprising a plurality of fine light emitting portions arranged in an array;
- and
- an imaging device array comprising:
- a plurality of unit imaging devices each comprising a lens portion made up of a first lens surface to which a light beam for imaging is incident and a second lens surface from which said light beam is output, and a roof prism portion for reflecting said light beam incident via said first lens surface toward said second lens surface, said plurality of unit imaging devices being arranged integrally with each other such that first lens surfaces, second lens surfaces and roof prism portions each are arranged in a respective array;
- and
- light attenuating means each intervening between nearby lens portions for attenuating light propagating between said nearby lens portions;
- wherein said light attenuating means has an attenuation ratio α smaller than 0.25.
4 more elements
An imaging device array comprising:
- a plurality of unit imaging devices each comprising a lens portion made up of a first lens surface to which a light beam for imaging is incident and a second lens surface from which said light beam is output, and a roof prism portion for reflecting said light beam incident via said first lens surface toward said second lens surface, said plurality of unit imaging devices being arranged integrally with each other such that first lens surfaces, second lens surfaces and roof prism portions each are arranged in a respective array;
- a rib formed at a corner where at least one of a face of said imaging device array where said first lens surface is positioned and a face where said second lens surface is positioned and a face where said roof prism portion is positioned join each other, said rib extending in a direction of arrangement of said unit imaging devices for guaranteeing mechanical strength;
- and
- light attenuating means each intervening between nearby lens portions for attenuating light propagating between said nearby lens portions;
- wherein said light attenuating means has an attenuation ratio α smaller than 0.25.
2 more elements
An imaging device array comprising:
- a plurality of unit imaging devices each comprising a lens portion made up of a first lens surface to which a light beam for imaging is incident and a second lens surface from which said light beam is output, and a roof prism portion for reflecting said light beam incident via said first lens surface toward said second lens surface, said plurality of unit imaging devices being arranged integrally with each other such that first lens surfaces, second lens surfaces and roof prism portions each are arranged in a respective array, wherein at least one of a face of said imaging device array where said first lens surface is positioned and a face where said second lens surface is positioned is processed for at least one of light attenuation and light scattering except for said first lens surface and said second lens surface;
- and
- light attenuating means each intervening between nearby lens portions for attenuating light propagating between said nearby lens portions;
- wherein said light attenuating means has an attenuation ratio α smaller than 0.25.
1 more element
An imaging device array comprising:
- a single transparent trigonal prism;
- a first lens array comprising a plurality of optically equivalent first lens surfaces arranged on a first face of said trigonal prism in an array in an axial direction;
- a second lens array comprising a plurality of optically equivalent second lens surfaces arranged on a second face of said trigonal prism in an array in the axial direction in one-to-one correspondence to said plurality of said first lens surfaces;
- a roof prism array comprising a plurality of optically equivalent roof prisms arranged on a third face of said trigonal prism in the axial direction with ridges extending perpendicularly to said axial direction;
- a plurality of unit imaging devices each comprising one of said first lens surfaces, one of said second lens surfaces and one of said roof prisms corresponding to each other;
- and
- a slit formed between nearby ones of pairs of said first lens surfaces and said second lens surfaces to thereby separate said pairs from each other, said slit having a rectangular section extending from a ridge between said first lens array and said second lens array toward said third face perpendicularly to the axial direction;
- wherein a distance D between a bottom of said slit and the ridge of said roof prism, a distance P between said pairs of said first lens surfaces and said second lens surfaces and a width W of said slit satisfy a relation:
- P/2<D<P/2+0.7{square root over ((W))}.
6 more elements
An optical writing unit comprising:
- a light emitting portion array comprising a plurality of fine light emitting portions arranged in an array;
- and
- an imaging device array for focusing light incident from said light emitting portion array on a writing surface;
- said imaging device array comprising:
- a plurality of unit imaging devices each comprising a lens portion made up of a first lens surface to which a light beam for imaging is incident and a second lens surface from which said light beam is output, and a roof prism portion for reflecting said light beam incident via said first lens toward said second lens surface, said plurality of unit imaging devices being arranged integrally with each other such that first lens surfaces, second lens surfaces and roof prism portions each are arranged in a respective array;
- a rib formed at a corner where at least one of a face of said imaging device array where said first lens surface is positioned and a face where said second lens surface is positioned and a face where said roof prism portion is positioned join each other, said rib extending in a direction of arrangement of said unit imaging devices for guaranteeing mechanical strength;
- and
- light attenuating means each intervening between nearby lens portions for attenuating light propagating between said nearby lens portions;
- wherein said light attenuating means has an attenuation ratio a smaller than 0.25.
6 more elements
An image forming apparatus comprising an optical writing unit for writing an image on a photoconductive element to thereby form an image, wherein said optical writing unit comprises:
- a light emitting portion array comprising a plurality of fine light emitting portions arranged in an array;
- and
- an imaging device array for focusing light incident from said light emitting portion array on a writing surface;
- said imaging device array comprising:
- a plurality of unit imaging devices each comprising a lens portion made up of a first lens surface to which a light beam for imaging is incident and a second lens surface from which said light beam is output, and a roof prism portion for reflecting said light beam incident via said first lens toward said second lens surface, said plurality of unit imaging devices being arranged integrally with each other such that first lens surfaces, second lens surfaces and roof prism portions each are arranged in a respective array;
- a rib formed at a corner where at least one of a face of said imaging device array where said first lens surface is positioned and a face where said second lens surface is positioned and a face where said roof prism portion is positioned join each other, said rib extending in a direction of arrangement of said unit imaging devices for guaranteeing mechanical strength;
- and
- light attenuating means each intervening between nearby lens portions for attenuating light propagating between said nearby lens portions;
- wherein said light attenuating means has an attenuation ratio α smaller than 0.25.
6 more elements
An imaging device array comprising:
- a single transparent trigonal prism;
- a first lens array comprising a plurality of optically equivalent first lens surfaces arranged on a first face of said trigonal prism in an array in an axial direction;
- a second lens array comprising a plurality of optically equivalent second lens surfaces arranged on a second face of said trigonal prism in an array in the axial direction in one-to-one correspondence to said plurality of first lens surfaces;
- a roof prism comprising a plurality of optically equivalent roof prisms arranged on a third face of said trigonal prism in the axial direction with ridges extending perpendicularly to said axial direction;
- a plurality of unit imaging devices each comprising one of said first lens surfaces, one of said second lens surfaces and one of said roof prisms corresponding to each other;
- and
- a slit formed between nearby ones of pairs of said first lens surfaces and said second lens surfaces to thereby separate said pairs from each other, said slit having a rectangular section extending from a ridge between said first lens array and said second lens array toward said third face perpendicularly to the axial direction, wherein walls of said slit are processed for reducing internal reflection such that a distance D between a bottom of said slit and the ridge of said roof prism, a distance P between said pairs of said first lens surfaces and said second lens surfaces and a width W of said slit satisfy a relation:
- P/2<D<P/2+0.7{square root over ((W))};
- and
- a rib formed at a corner where at least one of a face of said imaging device array where said first lens array is positioned and a face where said second lens array is positioned and a face where said roof prism array is positioned join each other, said rib extending in a direction of arrangement of said unit imaging devices for guaranteeing mechanical strength.
7 more elements
An imaging device array comprising:
- a single transparent trigonal prism;
- a first lens array comprising a plurality of optically equivalent first lens surfaces arranged on a first face of said trigonal prism in an array in an axial direction;
- a second lens array comprising a plurality of optically equivalent second lens surfaces arranged on a second face of said trigonal prism in an array in the axial direction in one-to-one correspondence to said plurality of first lens surfaces;
- a roof prism array comprising a plurality of optically equivalent roof prisms arranged on a third face of said trigonal prism in the axial direction with ridges extending perpendicularly to said axial direction;
- a plurality of unit imaging devices each comprising one of said first lens surfaces, one of said second lens surfaces and one of said roof prisms corresponding to each other;
- a slit fanned between nearby ones of pairs of said first lens surfaces and said second lens surfaces to thereby separate said pairs from each other, said slit having a rectangular section extending from a ridge between said first lens array and said second lens array toward said third face perpendicularly to the axial direction, wherein walls of said slit are processed for reducing internal reflection such that a distance D between a bottom of said slit and the ridge of said roof prism, a distance P between said pairs of said first lens surfaces and said second lens surfaces and a width W of said slit satisfy a relation:
- P/2<D<P/2+0.7{square root over ((W))}
- wherein at least one of said first face and said second face is processed for at least one of light absorption and light scattering except for said lens surfaces.
5 more elements
Dependencies are inferred from the claim text.