Abstract:
A light guide emits lights incident on an end face from an emitting face extending longitudinally of the guide, while having the lights reflected by its internal face. A sectional shape of the guide in a direction orthogonal to the longitudinal direction of this light guide has two opposite parabolas, a line segment connecting the focal points of the two opposite parabolas, and a line segment (bottom face) corresponding to the emitting face. A scattering pattern consisting of white ink is formed on the line segment (bottom face) connecting the focal points. With this guide, the face of a document is to be efficiently illuminated by conversely utilizing the characteristic of the compound parabolic concentrator (CPC) to convert scattered lights extending over a full angle from a limited area into radiant lights confined to a prescribed emission angle and thereby minimizing the expansion of lights.
Abstract:
A light guide member of the present invention is made of a light transmitting material. The light guide includes a light emitting surface 13, which extends in direction x and includes a lens surface 31 for converging light in direction y. The light guide also includes a light incident surface 11 provided at one of the ends spaced from each other in the direction x. The light emitting surface 13 includes a transitional region 13a adjacent to the light incident surface 11, where the transitional region includes the lens surface 31 and a round pillar surface 32. In the transitional region 13a, the lens surface 31 becomes less dominant in area as proceeding in the direction x toward the light incident surface 11.
Abstract:
An image reader includes a transparent plate (1) having end portions (1a and 1b) that are chamfered in a direction in which a document is carried thereon. The transparent plate (1) has recess portions (11aand 11b) formed in a lower surface thereof, and a housing (4) is engaged into the recess portions of the transparent plate. The image reader can prevent such a document as a check or banknote from being jammed, can be easily assembled and improve the reliability of the carrying of the document, and enables higher-speed reading.
Abstract:
An image reading apparatus is provided which includes a cold-cathode tube for irradiating a linearly extending image reading section, and a plurality of light receiving elements for receiving light reflected at the image reading section. The cold-cathode tube is provided with a first end portion, a second end portion, and an intermediate portion arranged between the first end portion and the second end portion. At least one of the first and the second end portions extends in a direction differing from another direction in which the intermediate portion extends. The image reading apparatus is also provided with a suitable number of shield members for preventing relatively weak image signals supplied by the light reading elements from being adversely influenced by electrical noises.
Abstract:
A sensor unit and LEDs are arranged on a sensor board. A light guide is placed above the resultant structure with be parallel to the sensor. The two end portions of the light guide are bent downward at right angles, and the bent end portions serve as incident portions on which light beams from the LEDs are incident. Light entering the light guide emerges from an exit portion to be irradiated on an original. The light reflected by the original is read by the sensor. The direction in which the reflected light is incident on the sensor is parallel with the direction in which the light from each LED is incident on the incident portion. With this structure, in the image sensor, electrical connection between the LEDs, the sensor unit, and an external system is facilitated.
Abstract:
A lens array unit includes first and second lens arrays cooperative with each other. The first lens array is provided with a plurality of first convex lenses and a first transparent holder formed integral with the first lenses. Each of the first lenses has first and second lens surfaces. The second lens array is provided with a plurality of second convex lenses and a second transparent holder formed integral with the second lenses Each of the second lenses has third and fourth lens surfaces. The second lens array is attached to the first lens array so that the third lens surfaces face the second lens surfaces. The lens array unit further includes a light shield mounted on the first lens array. The light shield is formed with a plurality of through-holes each facing the relevant one of the first lens surfaces.
Abstract:
An illuminator includes a light guide having a circular cross-section, a scatterer that is provided on a portion of the circumference of the circular cross-section and that radiates scattering light toward the inside of the light guide, and a condensing lens that condenses light emitted from the light guide and transforms the light into a linear beam, a planar beam. or a point-like beam. In the illuminator light from the light source is effectively utilized, and the light can efficiently illuminate the required illumination area. In addition, an image reader apparatus can perform high-speed reading using such an illuminator.
Abstract:
A contact-type image sensor includes a case having an upper surface formed with an opening, a cover glass closing the opening and providing a linear reading region extending in the primary scanning direction. A sheet as an object to be read, coming into contact with the linear reading region, is reciprocally moved in the secondary scanning direction which is perpendicular to the primary scanning direction. The opening is defined by a pair of edges of the case spaced in the secondary scanning direction. Each of the edges includes a convex surface having a top positioned above the outer surface of the cover glass.
Abstract:
A light guide emits lights incident on an end face from an emitting face extending longitudinally of the guide, while having the lights reflected by its internal face. A sectional shape of the guide in a direction orthogonal to the longitudinal direction of this light guide has two opposite parabolas, a line segment connecting the focal points of the two opposite parabolas, and a line segment (bottom face) corresponding to the emitting face. A scattering pattern consisting of white ink is formed on the line segment (bottom face) connecting the focal points. With this guide, the face of a document is to be efficiently illuminated by conversely utilizing the characteristic of the compound parabolic concentrator (CPC) to convert scattered lights extending over a full angle from a limited area into radiant lights confined to a prescribed emission angle and thereby minimizing the expansion of lights.
Abstract:
An image reading apparatus includes a light source, an elongate light guide member for guiding light emitted from the light source toward an image read line, and a plurality of light receiving elements for receiving light reflected at the image read line. The light guide member includes a first portion, a second portion, and a connecting portion for connecting the first portion and the second portion. The first portion includes a light incidence surface facing the light source for entry of light emitted from the light source, and the light incidence surface is convexly curved widthwise of the light guide member. The second portion includes a light exit surface oriented toward the image read line for emitting light toward the image read line. The connecting portion is narrower than the first portion and the second portion.