Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Minolta Camera Co., Ltd.

Satoshi Iwasaki

Takayuki Nabeshima

Toshihiko Ueda

Makoto Kumagai

Toshio Naiki

Nobuo Kanai

Kenji Takeshita

Kunihiko Konoma

Hiroki Kinoshita

Keijiro Sakamoto

Sanae Watanabe

Kazuharu Kagoshima

To read an image with high resolution via a CCD linear sensor having a limited pixel count, an image reading apparatus includes: a CCD linear sensor having arranged in a main-scanning direction photoelectric conversion elements for receiving a light reflected from an original; a piezoelectric element for providing a relative displacement between a light receiving surface of the CCD linear sensor and an object's image formed on the light receiving surface, according to a predetermined oscillation function and in the main-scanning direction; and a sensor drive circuit timing the CCD linear sensor's charge accumulation. The sensor drive circuit uses a distance from a center of an amplitude of the relative displacement to the CCD linear sensor and a time period of charge accumulation by the CCD linear sensor to determine a time point to start charge accumulation. The apparatus also includes a signal synthesizing circuit using image signals output from the CCD linear sensor during one period of the predetermined oscillation function to reconstruct an image signal of one line.

Image reading apparatus and scanner using photoelectric conversion unit with limited pixel count to read images with high resolution and method thereof

In order to correct chromatic aberration accurately and read out a document original properly, an image reader apparatus includes a chromatic aberration correction chart, a CCD linear sensor, and a correction processing unit. A chromatic aberration correction chart includes a high reflectance portion and a low reflectance portion lower than the high reflectance portion. A CCD linear sensor receives light reflected from the chromatic aberration correction chart. A correction processing unit corrects chromatic aberration of image data according to a light receiving position in the photoelectric conversion unit receiving light of a first wavelength included in the reflected light from the chromatic aberration correction chart and a light receiving position in the photoelectric conversion unit receiving light of a second wavelength included in the reflected light from the chromatic aberration correction chart.

Image reading apparatus that can correct chromatic aberration caused by optical system and chromatic aberration correction method

A two-dimensional area tilted illumination system has a long light source for emitting a light flux and a reflecting mirror having a generating line generally parallel to a longitudinal axis of the light source. A surface of the reflecting mirror has a first area for illuminating an illumination area after the light flux is first reflected and converged. The first area is shaped such that an intersection point of the light rays, reflected at two ends of the first area, is a position which results in the light rays impinging a center of the illumination area.

Two-dimensional area tilted illumination system having curved reflecting mirror

In a scanning optical system in which a plurality of light beams emitted from a plurality of light sources are, after being formed into beams converging in a predetermined manner, deflected by a single deflector and are then shone, through scanning lens systems provided one for each light beam, onto a scanned surface so that the scanned surface is scanned by the light beams for image formation, at least one of the scanning lens systems satisfies the condition 0&lt;-{(L-HH')+k}/k.ltoreq.0.2, where L represents the distance from the point of deflection of the light beam to the scanned surface, HH' represents the distance from the front-side principal point to the rear-side principal point of the scanning lens system, and k (k&lt;0) represents the constant of proportionality defined by the formula y'=k.theta., where y' represents the image height on the scanned surface in the main scanning direction, and .theta. represents the angle of deflection, that is, the angle that the light beam, after being deflected by the deflector, forms with respect to the optical axis of the scanning lens system.

Scanning optical system and a scanning optical apparatus

A radial gradient index lens system has a refractive index distribution. The refractive index decreases from an optical axis along a height. The lens system has two meniscus lens elements whose convex surfaces have a larger radius of curvature than concave surfaces. The meniscus lens elements are arranged symmetrically with respect to an aperture stop so that the convex surfaces thereof face an object side and an image side, respectively. The gradient index lens system is for use in a copying apparatus or as a reading optical system.

Gradient index lens system

A collimator lens system has a single plano-convex lens and a plane parallel plate. An aspherical surface of the single plano-convex lens is convex to the magnification-larger-than-unity side. The collimator lens system fulfills the following conditions: ##EQU1## where n represents a refractive index of the single plano-convex lens, d represents an axial thickness of the single plano-convex lens, f represents a focal length of the single plano-convex lens and dg represents a thickness of the plane parallel plate.

Single aspherical plano-convex collimator lens

An illumination system for use in an image projection apparatus, having a light source assembly which includes a lamp and a concave reflector for producing convergent light, and an illumination lens group which includes, in order from the light source assembly side, a first lens unit of a negative power movable along the optical axis, a second lens unit of a positive power and a third lens unit of a positive power. The illumination lens group fulfills the following equation,

Illumination system for use in image projection apparatus

A zoom lens system including, from an enlargement side, a first lens unit of a positive power, a second lens unit of a positive power and a third lens unit of a negative power. The first and third lens units monotonously move toward a reduction side during a zooming operation from the longest focal length condition to the shortest focal length condition, while the second lens unit which is closest to the third lens unit at the longest focal condition moves so as to be most proximate to the first lens unit at the shortest focal length condition. The zoom lens system fulfills the following conditions,

Zoom lens system

A zoom lens system comprising, in order from an enlargement side, a first lens unit of a positive power, a second lens unit of a positive power, a third lens unit of a negative power, and a fourth lens unit of a positive power. During a magnification varying operation from a longest focal length condition to a shortest focal length condition, the first lens unit, the third lens unit and the fourth lens unit are movable simply from the enlargement side to a reduction side. The second lens unit is closest to the third lens unit in the longest focal length condition, and closest to the first lens unit in the shortest focal length condition. This zoom lens system satisfies the following conditions:

A zoom lens system comprising, in order from an enlargement side, a first lens unit of a negative power, a second lens unit of a positive power and a third lens unit of a negative power. The first lens unit is fixed during a zooming operation from a longest focal length condition to a shortest focal length condition. The second and third lens units are movable from the enlargement side to a reduction side during the zooming operation, with a distance therebetween changing from a decrease to an increase.

Zoom lens system for use in a microfilm projection apparatus

An illumination system for use in an image projection apparatus, having a light source assembly which includes a lamp and a concave reflector for producing convergent light, and an illumination lens group which includes, in order from the light source assembly side, a first lens unit of a negative power, a second lens unit of a positive power movable along the optical axis and a third lens unit of a positive power. The illumination lens group fulfills the following equation,

A zoom lens system for use in a microfilm projection apparatus, having from enlargement side a first lens unit of a negative refractive power, a second lens unit of a positive refractive power and a third lens unit of a negative refractive power and including an aperture stop positioned within the second lens unit or in the vicinity thereof. The first lens unit consists of one or more meniscus lens elements each having a concave surface faced to the reduction side and the third lens unit consists of one or more meniscus lens elements each having a concave surface faced to the enlargement side. Zooming operation from the longest focal length side to the shortest focal length side is carried out by linearly moving both the second and third lens units to the reduction side along the optical axis while first lens unit is fixed. Such structure reduces a distortion as well as a variation thereof during the zooming operation. Moreover, the fixed location of the first lens unit reduces the length of the whole zoom lens system to thereby provide it being compact.

Zoom lens system for use in microfilm projection apparatus

There is disclosed a lens system for projecting images of microfilm onto a screen or the like. The lens system is characterized by five lens components, that is, a first positive meniscus lens component convex to the magnification side, a second negative meniscus lens component concave to the magnification side, a third biconvex lens component, a fourth biconcave lens component having a powerful concave surface faced to the magnification side, and a fifth biconvex lens component.

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Toyokawa, Japan

Satoshi Iwasaki