Abstract: A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.

Abstract: A virtual screen display apparatus includes a display arranged to generate display information and having an effective diagonal length DLC and an optical projecting element arranged to receive the display information from the display and to project and form an image, the optical projecting element having an effective F number which is defined by Fe=S1/PuD wherein S1 is a distance between the display and a principal point of the optical projecting element and PuD is a diameter of an exit pupil of the optical projecting element. A field optical element arranged to form an in-space image in a position of a virtual screen and to direct a divergent light flux from the virtual screen to a view region where the image is viewable to an observer.

Abstract: A virtual screen display apparatus includes a display arranged to generate display information and having an effective diagonal length DLC and an optical projecting element arranged to receive the display information from the display and to project and form an image, the optical projecting element having an effective F number which is defined by Fe=S1/PuD wherein S1 is a distance between the display and a principal point of the optical projecting element and PuD is a diameter of an exit pupil of the optical projecting element. A field optical element arranged to form an in-space image in a position of a virtual screen and to direct a divergent light flux from the virtual screen to a view region where the image is viewable to an observer.

Abstract: A multiple-optical scanner includes an optical source that produces a plurality of optical beams such that the plurality of optical beams cross each other substantially at a location of a rotary polygonal mirror when viewed in a direction of a rotational axis of the rotary polygonal mirror.

Abstract: In an image forming apparatus, a device for removing an image forming substance from a paper or similar image holding medium senses the orientation of fibers constituting the paper. While a light beam is emitted obliquely toward the paper, the diffused distribution distribution of the resulting reflection is measured in order to determine the orientation of the fibers. A preselected relation is set up between the fibers and the direction of paper transport on the basis of the determined orientation. Further, a condition for applying an unstabilizing liquid to the paper and a condition for drying the paper are varied on the basis of the determined orientation.

Abstract: In an image forming apparatus, a device for removing an image forming substance from a paper or similar image holding medium senses the orientation of fibers constituting the paper. While a light beam is emitted obliquely toward the paper, the diffused distribution distribution of the resulting reflection is measured in order to determine the orientation of the fibers. A preselected relation is set up between the fibers and the direction of paper transport on the basis of the determined orientation. Further, a condition for applying an unstabilizing liquid to the paper and a condition for drying the paper are varied on the basis of the determined orientation.

Abstract: In an optical scanner, a light beam from a light source device is incident to a deflecting reflecting face of an optical deflector. The light beam reflected on the deflecting reflecting face is deflected by rotating or swinging the deflecting reflecting face and is incident to a reflective image forming element. The light beam is converged as a light spot onto a scanned face by the reflective image forming element to perform an optical scanning operation. The deflecting reflecting face is substantially parallel to a rotating or swinging axis thereof. The light beam from the light source device is incident to the deflecting reflecting face in a state in which this light beam is inclined with respect to an axial perpendicular face perpendicular to the rotating or swinging axis. An optical axis of the reflective image forming element is inclined with respect to the axial perpendicular face such that this optical axis approaches the incident deflected light beam emitted from the deflecting reflecting face.

Abstract: An LED array head comprises a plurality of LED elements and a reflecting element, wherein the reflecting element directs luminous flux emitted from the LED element in a direction substantially perpendicular to the luminous flux emitting direction.

Abstract: In an optical scanner, an optical deflector has a deflecting reflecting face rotated at an equal speed. A light beam from a light source is deflected on a plane by the deflector at an equal angular velocity and is incident to a reflective image-forming element through a half mirror inclined with respect to a beam deflecting face. The light beam reflected on the reflective image-forming element is reflected on the half mirror and is converged by an image-forming action of the reflective image-forming element as a light spot on a scanned face to perform an optical scanning operation. The reflective image-forming element has a function for substantially performing the optical scanning operation using the light spot at an equal speed. The reflective image-forming element is arranged such that the reflective image-forming element is shifted by a predetermined shifting amount in a direction perpendicular to the beam deflecting face to correct the curve of a scanning line on the scanned face.

Abstract: In an optical scanner, a light source emits a light beam and a coupling lens changes this light beam to a convergent, divergent or parallel light beam. An optical deflector deflects the light beam from the coupling lens at an equal angular velocity. The deflected light beam is converged onto a scanned face by an image forming mirror and an elongated cylindrical optical element to perform an optical scanning operation at an equal speed. An optical path separating device separates an optical path of light reflected on the image forming mirror from an optical path of incident light from the light source to the image forming mirror. A reflecting face of the image forming mirror is constructed by a coaxial aspherical surface.

Abstract: The present invention relates to an optical scanning system for deflecting a light beam from a light source by a rotating deflector, reflecting the deflected light beam onto an f.theta. mirror having f.theta. characteristics, and focussing the reflected light beam as a light spot on a scanned surface to thereby carry out optical writing and optical scanning. The f.theta. mirror is unitedly formed with an optical housing.

Abstract: A scanning optical system has a light source for emitting a light beam; a condenser lens for changing the light beam from the light source to a parallel light beam; a connection holding member for supporting the light source and the condenser lens; a deflector for deflecting an approximately parallel light beam transmitted from the condenser lens at an equiangular velocity; and a lens for optical scanning for scanning a scanned face at an approximately equal speed while converging the light beam deflected by the deflector and forming an image in the shape of a spot on the scanned face, the lens for optical scanning being formed by a plastic material for optics.

Abstract: In an image forming reflecting mirror for a constant speed optical scan, a light beam is convergent in a cross scan-corresponding direction with a point near a starting point of deflection as a starting point of the light beam, and the light beam is deflected at an equal angular velocity and is converged to form a light spot on a scanned face so as to optically scan the scanned face at a constant speed. The image forming reflecting mirror has a shape on a deflecting-reflecting face represented by the following general formula, Y.sup.2 =2RmX-(K+1)X.sup.2, where X designates a coordinate in the direction of an optical axis and Y designates a coordinate in a direction perpendicular to the optical axis with a position on the optical axis as an origin, and Rm designates a radius of curvature on the optical axis and K designates a conical constant.

Abstract: Reflecting faces constituting one or more reflecting face pairs are respectively inclined at 45 degrees with respect to the rotational axis of an optical deflecting element. The reflecting faces are opposed to each other such that these reflecting faces are perpendicular to each other. The reflecting face pairs are arranged with axial symmetry with respect to the rotational axis. A light beam is incident to one of the reflecting faces in parallel to the rotational axis. This light beam is sequentially reflected on this one reflecting face and the other reflecting face constituting the reflecting face pairs together with this one reflecting face. Then, the light beam is returned from the other reflecting face in parallel to the rotational axis and is emitted as a deflected light beam. An optical scanner using the return optical deflecting element and an optical deflecting element is also shown.

Abstract: An optical scanner has a light source device; a lens for converging a laser beam emitted from the light source device; a deflector having a mirror face which is integrally formed with the shaft of a scanner motor and is constructed by one convex spherical or cylindrical mirror face having a radius R and approximately arranged in the vicinity of a center of rotation of the shaft of the scanner motor; and a scanning face scanned by a light beam deflected by the deflector. The optical scanner satisfies a predetermined relation with respect to the radius R when a distance L.sub.O from a deflecting point to the scanning face at an angle of rotation of the deflector set to zero is equal to a distance L from the deflecting point to the scanning face at the angle of rotation of the deflector set to .theta.. The predetermined relation is provided by the following formula:R={(1/cos.theta.)+cos.theta./(1+cos.theta.)-1}L.sub.oThe light source device uses an element for emitting two or more light beams.

Abstract: A scanning optical system has a light source for emitting a light beam; a condenser lens for changing the light beam from the light source to a parallel light beam; a connection holding member for supporting the light source and the condenser lens; a deflector for deflecting an approximately parallel light beam transmitted from the condenser lens at an equiangular velocity; and a lens for optical scanning for scanning a scanned face at an approximately equal speed while converging the light beam deflected by the deflector and forming an image in the shape of a spot on the scanned face, the lens for optical scanning being formed by a plastic material for optics.

Abstract: A scanning apparatus comprises a light source for emitting a light along an optical axis, a focusing lens for converting the light emitted from the light source into a convergent light, a deflector for deflecting the convergent light from the focusing lens so that a deflected light is scanned at a substantially uniform angular velocity on an image surface, the deflector having a deflection surface on which the convergent light is deflected, and a scanning lens for focusing the deflected light from the deflector so that a focused light is scanned on the image surface in a main scanning direction to form scanning spots thereon at a substantially uniform scanning rate, the scanning lens being made of a material with a refractive index n and constructed as a single lens having a focal length f. The scanning lens according to the present invention provides a well corrected curvature of field in the main scanning direction and at the same time a good scanning linearity.

Abstract: An optical scanning system includes a light source, a coupling lens, a polygon mirror, an f.theta. lens, and a barrel toroidal lens. The barrel toroidal lens includes a barrel toroidal surface in which the radius of curvature thereof measured in the sub-scanning direction decreases with an increased distance from the optical axis of the barrel toroidal lens in a direction parallel to the main scanning direction.

Abstract: A scanning optical system for use in a light scanner including a light deflector for deflecting a light beam to scan a surface is disposed between the light deflector and the scanned surface. The scanning optical system focuses the defelcted light beam onto the scanned surface and keeps the scanned surface and a light beam deflecting point in substantially conjugate relationship in an auxiliary scanning direction for thereby correcting facet errors of the light deflector. The scanning optical system has a saddle-shaped convex toroidal surface having a radius of curvature in a cross section along the auxiliary scanning direction, the radius of curvature being progressively greater in a direction away from the optical axis of the scanning optical system. The scanning optical system satisfies the following condition:d/f.sub.M >0.6where f.sub.

Abstract: A semiconductor laser source unit includes a semiconductor laser chip emitting a laser beam, a base member supporting the semiconductor laser chip, and a protection cover mounted on the base member so as to seal the semiconductor laser chip. The protection cover has a lid portion formed at an end thereof and an opening at an opposed end thereof facing the base member. The lid portion has a window. The semiconductor laser source unit also has a single aspherical lens fastened to the lid portion of the protection cover so as to cover the window formed in the lid portion. The single aspherical lens collimates the laser beam emitted from the semiconductor laser chip.