Abstract: Obtained are an imaging optical system having a simple structure in which imaging position deviation due to deformation caused by a weight of an off-axial optical element is reduced and an image reading apparatus using the same. According to an imaging optical system for image reading, image information on an original surface is imaged on a sensor, and is read by the sensor. The imaging optical system includes reflection-type off-axial optical elements, each of which has an outer shape whose lengths in directions orthogonal to each other are different from each other and whose thickness is smaller than a length of the outer shape in a short-direction thereof and is made of a resin material. The plurality of off-axial optical elements are disposed such that mirror surfaces thereof are opposed to each other and constructed to satisfy a conditional expression.

Abstract: A light guide optical system guides a plurality of light beams emitted from a plurality of point light sources arranged linearly to a predetermined surface. The light guide optical system has a plurality of optical surfaces arranged periodically in the arrangement direction of the plurality of point light sources. Each of the plurality of optical surfaces has power in the arrangement direction of the plurality of point light sources.

Abstract: An image reading apparatus in which an original is illuminated with visible light and with infrared light, and in which a lens assembly forms an image of the original on the surface of a reading device such as a CCD. The lens assembly is housed in a lens barrel. A focus correcting device such as a flat glass or resin plate is movably mounted to the lens barrel, so as to correct defocus of the original on the surface of the reading device due to differences in wavelength between the visible light and the infrared light. The lens assembly includes a resin lens which is disposed on a side of the lens assembly nearest to the reading device, and which is mounted in close proximity to the focus correcting device.

Abstract: Obtained are an imaging optical system having a simple structure in which imaging position deviation due to deformation caused by a weight of an off-axial optical element is reduced and an image reading apparatus using the same. According to an imaging optical system for image reading, image information on an original surface is imaged on a sensor, and is read by the sensor. The imaging optical system includes reflection-type off-axial optical elements, each of which has an outer shape whose lengths in directions orthogonal to each other are different from each other and whose thickness is smaller than a length of the outer shape in a short-direction thereof and is made of a resin material. The plurality of off-axial optical elements are disposed such that mirror surfaces thereof are opposed to each other and constructed to satisfy a conditional expression.

Abstract: An image reading apparatus with an image reading lens configured to reduce a field curvature and a magnification error in the sub-scan direction, includes a photoelectric conversion element having picture elements arrayed in the main-scan direction, and an image reading lens for imaging imagewise information on a surface of an original, upon a light receiving surface of the photoelectric conversion element, the image reading lens including at least one anamorphic lens having anamorphic surfaces formed at a light entrance surface and a light exist surface thereof, respectively, wherein, when a sectional shape of the anamorphic surface in a main-scan section which contains an optical axis of the image reading lens and the main-scan direction, is taken as a meridional, a curvature of a sagittal of the anamorphic surface defined within a plane being perpendicular to the main-scan section and containing a normal to the anamorphic surface at an arbitrary position in the meridional direction, changes continuously al

Abstract: Obtained are an imaging optical system having a simple structure in which imaging position deviation due to deformation caused by a weight of an off-axial optical element is reduced and an image reading apparatus using the same. According to an imaging optical system for image reading, image information on an original surface is imaged on a sensor, and is read by the sensor. The imaging optical system includes reflection-type off-axial optical elements, each of which has an outer shape whose lengths in directions orthogonal to each other are different from each other and whose thickness is smaller than a length of the outer shape in a short-direction thereof and is made of a resin material. The plurality of off-axial optical elements are disposed such that mirror surfaces thereof are opposed to each other and constructed to satisfy a conditional expression.

Abstract: A lens unit and an image reading apparatus configured to hold an anamorphic lens precisely with a simple structure, without a lens spacing error or eccentric error: the lens unit including a barrel member configured to hold at least one rotationally symmetric lens having a rotationally symmetric shape with respect to an optical axis; an anamorphic lens having at least one anamorphic surface circumscribing an end portion of the barrel member; a coaxiality maintaining device configured to engage the anamorphic lens and the barrel member with each other to align central axes of the anamorphic lens and the barrel member with each other, and arranged relatively rotate the anamorphic lens and the barrel member relative to each other with reference to the aligned central axes of them; and an elastic member configured to push the anamorphic lens against the barrel member.

Abstract: An image reading apparatus with an image reading lens configured to reduce a field curvature and a magnification error in the sub-scan direction, includes a photoelectric conversion element having picture elements arrayed in the main-scan direction, and an image reading lens for imaging imagewise information on a surface of an original, upon a light receiving surface of the photoelectric conversion element, the image reading lens including at least one anamorphic lens having anamorphic surfaces formed at a light entrance surface and a light exist surface thereof, respectively, wherein, when a sectional shape of the anamorphic surface in a main-scan section which contains an optical axis of the image reading lens and the main-scan direction, is taken as a meridional, a curvature of a sagittal of the anamorphic surface defined within a plane being perpendicular to the main-scan section and containing a normal to the anamorphic surface at an arbitrary position in the meridional direction, changes continuously al

Abstract: An image reading apparatus including a light source for illuminating an original, a plurality of mirrors for reflecting a light beam from the original illuminated by the light source, a reading device, an imaging optical system for imaging a light beam reflected by the mirrors, upon the reading device, and a scanning optical system unit which integrally accommodates theses components therein and moves in a sub-scan direction to read imagewise information of the original, wherein, in a sub-scan section, one mirror optically closest to the surface of the original is disposed in an end portion of the scanning optical system unit in the sub-scan direction, as compared with the other mirrors, and wherein the central portion of the reflection surface of one mirror optically closest to the original is disposed in a space between the central portion of the reflection surface of a mirror optically closest to the light entrance surface of the imaging optical system and central portions reflection surfaces of other mirr

Abstract: Obtained are an imaging optical system having a simple structure in which imaging position deviation due to deformation caused by a weight of an off-axial optical element is reduced and an image reading apparatus using the same. According to an imaging optical system for image reading, image information on an original surface is imaged on a sensor, and is read by the sensor. The imaging optical system includes reflection-type off-axial optical elements, each of which has an outer shape whose lengths in directions orthogonal to each other are different from each other and whose thickness is smaller than a length of the outer shape in a short-direction thereof and is made of a resin material. The plurality of off-axial optical elements are disposed such that mirror surfaces thereof are opposed to each other and constructed to satisfy a conditional expression.

Abstract: Obtained are an imaging optical system having a simple structure in which imaging position deviation due to deformation caused by a weight of an off-axial optical element is reduced and an image reading apparatus using the same. According to an imaging optical system for image reading, image information on an original surface is imaged on a sensor, and is read by the sensor. The imaging optical system includes reflection-type off-axial optical elements, each of which has an outer shape whose lengths in directions orthogonal to each other are different from each other and whose thickness is smaller than a length of the outer shape in a short-direction thereof and is made of a resin material. The plurality of off-axial optical elements are disposed such that mirror surfaces thereof are opposed to each other and constructed to satisfy a conditional expression.

Abstract: An image reading apparatus includes a visible light source; an infrared light source; at least three one-dimensional photoelectric conversion elements extending in a main scanning direction and having respective different spectral sensitivity characteristics; an imaging optical system configured to form an image of image information of an original placed on an original holder and irradiated by the visible light source and the infrared light source on the one-dimensional photoelectric conversion elements; a driving unit configured to change relative optical positions of the imaging optical system and the original in a sub-scanning direction; and a control unit configured to obtain visible-light image information and infrared-light image information of the original by controlling turning-on operations of the visible light source and the infrared light source at every reading in the main scanning direction and by performing relative movement of the image optical system and the original in the sub-scanning direct

Abstract: Obtained are an imaging optical system having a simple structure in which imaging position deviation due to deformation caused by a weight of an off-axial optical element is reduced and an image reading apparatus using the same. According to an imaging optical system for image reading, image information on an original surface is imaged on a sensor, and is read by the sensor. The imaging optical system includes reflection-type off-axial optical elements, each of which has an outer shape whose lengths in directions orthogonal to each other are different from each other and whose thickness is smaller than a length of the outer shape in a short-direction thereof and is made of a resin material. The plurality of off-axial optical elements are disposed such that mirror surfaces thereof are opposed to each other and constructed to satisfy a conditional expression.

Abstract: An image processing apparatus for processing visible image information and invisible image information obtained from visible light and invisible light directed onto an original and from the original onto an image pick-up element via a focusing optical system. The image processing apparatus includes an infrared light source, a visible light source, a focus correction unit that corrects the focus of the images when the images are formed on the image pick-up element and acquired, and a signal processor that corrects a partial magnification difference between the visible image and the infrared image.

Abstract: The invention aims at obtaining an original illuminating apparatus and an image reader having the same with which “the reflection” phenomenon is reduced, and much quantity of light for illumination is obtained in an area to be read of an original to thereby be able to perform the reading operation at high speed.

Abstract: An object is to provide an imaging optical system having a very simple structure that can read image while maintaining excellent image quality without suffering from significant asymmetrical aberrations. An imaging optical system for image reading is adapted to form an image of image information on a surface of an original onto a line sensor while changing a relative position of the original surface and the line sensor to allow the line sensor to read the image information. The imaging optical system includes two off-axial reflecting surfaces, and the two off-axial surfaces are a plus deflecting surface and a minus deflecting surface, or a minus deflecting surface and a plus deflecting surface disposed in the mentioned order from the original surface side, where an off-axial reflecting surface that deflects a reference axis beam clockwise is defined as a minus deflecting surfaces and an off axial reflecting surface that deflects the reference axis beam anticlockwise is defined as a plus deflecting surface.

Abstract: Disclosed is a method of adjusting an image reading apparatus which reads image information of an original by moving relative to the original a carriage retaining a light source, a slit portion, a plurality of mirrors, an imaging device including an optical element with an optical surface rotationally asymmetrical with respect to the optical axis, and a reading device, the method including placing an adjustment chart allowing resolving power evaluation in the sub scanning direction on an original table glass, illuminating the adjustment chart by the light source, and adjusting, by using an image of the adjustment chart thus illuminated, the relative positional relationship in the sub scanning direction among the slit portion, the imaging device, and the reading device by a positioning adjustment device such that imaging of the light beam passing through a slit center of the slit portion is effected on the surface of the reading device.

Abstract: To provide an image formation optical system which is excellent in image formation performance while reducing an opening angle of an anamorphic lens, and an image reading apparatus using the same. When a thickness of an anamorphic lens is da, a thickness of a meniscus lens arranged adjacent to the anamorphic lens is dm, an interval between the anamorphic lens and the meniscus lens adjacent thereto is tin, and a distance between a lens surface of the lens, of both the lenses, nearest an aperture stop, and a lens surface of the lens, other than both the lenses, facing that lens surface is tout, the constituent elements are set so as to satisfy the following condition: tin<dm+da<tout.

Abstract: To provide an image formation optical system which is excellent in image formation performance while reducing an opening angle of an anamorphic lens, and an image reading apparatus using the same.

Abstract: The invention aims at obtaining an original illuminating apparatus and an image reader having the same with which “the reflection” phenomenon is reduced, and much quantity of light for illumination is obtained in an area to be read of an original to thereby be able to perform the reading operation at high speed.