Back to results
US 6,724,537 B2Granted
Lens array for unity magnification imaging, and image reading apparatus using the same array
AssigneeNippon Sheet Glass Co., Ltd.
InventorShuya Ogi
Life of this patent
Estimating the term…
Abstract
A miniaturized lens array for unity magnification imaging comprises a plurality of rod lenses arranged in one row. An arrangement pitch D of the rod lenses is defined to satisfy (2 m+1)·D≦2.1 mm or 2.5 mm. An angle of aperture θ of the rod lens is defined to satisfy αD/6×{n·cos−1(−α/2/m)+(4 m2/α2−1)1/2}≦θ≦αD/2×(4/m2/α2−1)1/2. The arrangement pitch D and angle of aperture θ are defined in this manner, and it is therefore possible to obtain the lens array whose difference between a total width and effective lens width is equal to or smaller than 2.1 mm or 2.5 mm.
Claims14
A lens array for unity magnification imaging, comprising:
- a plurality of rod lenses arranged in at least one row at a lens arrangement pitch D, each rod lens having an angle of aperture θ, the lens arrangement pitch D being defined to satisfy the following equation (1):
- (2 m+1)·D≦2.1 mm (1),
- wherein m is an overlap degree of the plurality of rod lenses,
- the angle of aperture θ of the rod lens being defined to satisfy the following equation (2):
- αD/6×{n·cos−1(−α/2/m)+(4 m2/α2−1)1/2}≦θ≦αD/2×(4 m2/α2−1)1/2 (2),
- wherein n is a refractive index on an optical axis of the rod lens, d is an effective diameter of the rod lens, α is a filling factor of the lens array, the overlap degree m is set in a range of 1.53 to 3.00 when the plurality of rod lenses are arranged in odd-numbered rows, and the overlap degree is set in a range of 1.10 to 3.00 when the plurality of rod lenses are arranged in even-numbered rows.
3 more elements
A lens array for unity magnification imaging, comprising:
- a plurality of rod lenses arranged in at least one row at a lens arrangement pitch D, each rod lens having an angle of aperture θ, the lens arrangement pitch D being defined to satisfy the following equation (1):
- (2 m+1)·D≦2.5 mm (1),
- wherein m is an overlap degree of the plurality of rod lenses,
- the angle of aperture θ of the rod lens being defined to satisfy the following equation (2):
- αD/6×{n·cos−1(−α/2/m)+(4 m2/α2−1)1/2}≦θ≦αD/2×(4 m2/α2−1)1/2 (2),
- wherein n is a refractive index on an optical axis of the rod lens, d is an effective diameter of the rod lens, α is a filling factor of the lens array, the overlap degree m is set in a range of 1.53 to 3.00 when the plurality of rod lenses are arranged in odd-numbered rows, and the overlap degree is set in a range of 1.10 to 3.00 when the plurality of rod lenses are arranged in even-numbered rows.
3 more elements
An image reading apparatus comprising:
- a light source for irradiating an original copy with illuminating light;
- a lens array for unity magnification imaging, for forming the light reflected by the original copy into an image;
- and
- a photoelectric conversion unit disposed in an image formation point of the lens array, the lens array for unity magnification imaging including:
- a plurality of rod lenses arranged in at least one row at a lens arrangement pitch D, each rod lens having an angle of aperture θ, the lens arrangement pitch D being defined to satisfy the following equation (1):
- (2 m+1)·D≦2.1 mm (1),
- wherein m is an overlap degree of the plurality of rod lenses,
- the angle of aperture θ of the rod lens being defined to satisfy the following equation (2):
- αD/6×{n·cos−1(−α/2/m)+(4 m2/α2−1)1/2}≦θ≦αD/2×(4 m2/α2−1)1/2 (2),
- wherein n is a refractive index on an optical axis of the rod lens, d is an effective diameter of the rod lens, α is a filling factor of the lens array, the overlap degree m is set in a range of 1.53 to 3.00 when the plurality of rod lenses are arranged in odd-numbered rows, and the overlap degree is set in a range of 1.10 to 3.00 when the plurality of rod lenses are arranged in even-numbered rows.
7 more elements
An image reading apparatus comprising:
- a light source for irradiating an original copy with illuminating light;
- a lens array for unity magnification imaging, for forming the light reflected by the original copy into an image;
- and
- a photoelectric conversion unit disposed in an image formation point of the lens array, the lens array for unity magnification imaging including:
- a plurality of rod lenses arranged in at least one row at a lens arrangement pitch D, each rod lens having an angle of aperture θ, the lens arrangement pitch D being defined to satisfy the following equation (1):
- (2 m+1)·D≦2.5 mm (1),
- wherein m is an overlap degree of the plurality of rod lenses,
- the angle of aperture θ of the rod lens being defined to satisfy the following equation (2):
- αD/6×{n·cos−1(−α/2/m)+(4 m2/α2−1)1/2}≦θ≦αD/2×(4 m2/α2−1)1/2 (2),
- wherein n is a refractive index on an optical axis of the rod lens, d is an effective diameter of the rod lens, α is a filling factor of the lens array, the overlap degree m is set in a range of 1.53 to 3.00 when the plurality of rod lenses are arranged in odd-numbered rows, and the overlap degree is set in a range of 1.10 to 3.00 when the plurality of rod lenses are arranged in even-numbered rows.
7 more elements
Dependencies are inferred from the claim text.