Abstract: The present invention provides an image forming apparatus, which is able to prevent the adherence of toner on the surface of toner controlling means and around a toner passage hole, and to stably carry out toner passage ON/OFF control when forming an image using the direct recording method. This image forming apparatus includes: a toner carrier; recording medium means; toner controlling means, disposed between the toner carrier and recording medium means, and having a plurality of toner passage holes; and cloud electrode means disposed between the toner carrier and toner controlling means, a toner cloud being formed by applying an AC bias between the toner carrier and cloud electrode means.

Abstract: An image forming device includes a plurality of image forming units provided in parallel comprising a black image forming unit to form a black toner image and a plurality of color image forming units to form color toner images, an intermediate transfer device to primarily transfer color toner images formed by superimposing the toner images formed at each image forming unit, and a secondary transfer unit to transfer the color toner image to a transfer paper. The color image forming unit employs a non-magnetic-contact-type single-component development device to develop each color toner image with a single-component developer, and the black image forming unit is provided closest to the secondary transfer unit and employs a contact-type two-component development device to develop a black toner image with a two-component developer.

Abstract: An image forming apparatus, in which an image forming method is performed, includes an image carrier, an optical writing unit, a developing unit developing a toner image including an output image and a forcible toner consumption image, a transfer unit including an endless moving member to transfer the toner image onto the endless moving member directly or a recording medium carried on the endless moving member, a first remover to remove residual toner from the image carrier after transfer, a toner recycling unit to convey the residual toner to the developing unit, a controller to form the forcible toner consumption image and transfer the forcible toner consumption image onto the surface of the endless moving member, and a second remover to remove the forcible toner consumption image from the endless moving member.

Abstract: A developing device includes a toner supplying roller, a developing roller for transferring the one-component toner to a developing position by performing a developing rotation in an image forming operation and moving away from the developing position, a sealing member arranged in a vicinity of the developing roller, and a toner layer regulating roller arranged in contact with the developing roller for locking a rotating operation in the image forming operation, for regulating the one-component toner which adheres on a surface of the developing roller into a thin layer and for freely following the developing roller in a non-image forming operation. A compulsory toner consumption operation is performed to supply toner onto the image bearing member after termination of the non-image forming operation.

Abstract: A developing device includes a toner supplying roller, a developing roller for transferring the one-component toner to a developing position by performing a developing rotation in an image forming operation and moving away from the developing position, a sealing member arranged in a vicinity of the developing roller, and a toner layer regulating roller arranged in contact with the developing roller for locking a rotating operation in the image forming operation, for regulating the one-component toner which adheres on a surface of the developing roller into a thin layer and for freely following the developing roller in a non-image forming operation.

Abstract: A developing device includes a toner supplying roller, a developing roller for transferring the one-component toner to a developing position by performing a developing rotation in an image forming operation and moving away from the developing position, a sealing member arranged in a vicinity of the developing roller, and a toner layer regulating roller arranged in contact with the developing roller. The toner layer regulating roller locks a rotating operation in the image forming operation, regulates the one-component toner which adheres on a surface of the developing roller into a thin layer, and freely follows the developing roller in a non-image forming operation.

Abstract: A developing device for an image forming apparatus of the present invention includes an image carrier performing endless movement while carrying a developer in the form of a layer thereon, and a regulating member for regulating the thickness of the layer. Toner stored in the developing device is covered with an additive whose particle size is less than 2 &mgr;m. The regulating member is implemented as a doctor roller having a surface roughness Rz equal to or greater than the above particle size, but smaller than 2 &mgr;m. The doctor roller is pressed against a developing roller or developer carrier by a preselected pressure, forming a nip for development. The developing device reduces irregular development ascribable to impurities caught at a regulating position assigned to the doctor roller more than a conventional developing device using a doctor blade as a regulating member.

Abstract: A development apparatus includes a development roller, a supplying roller, and a toner layer regulating member. The development roller contacts an image carrying member and develops an electrostatic latent image into a toner image on the image carrying member. The development roller may be made of aluminum and is rotatably mounted in the apparatus. The supplying roller supplies toner to the development roller. The toner layer regulating member regulates the toner to form a thin film on the development roller. The toner layer regulating member has a roller shape, a surface roughness Rz in a range of from 0.5 &mgr;m to 2 &mgr;m, and a dynamic friction coefficient in a range of from 0.1 to 0.8.

Abstract: A developing device for an image forming apparatus of the present invention includes an image carrier performing endless movement while carrying a developer in the form of a layer thereon, and a regulating member for regulating the thickness of the layer. Toner stored in the developing device is covered with an additive whose particle size is less than 2 &mgr;m. The regulating member is implemented as a doctor roller having a surface roughness Rz equal to or greater than the above particle size, but smaller than 2 &mgr;m. The doctor roller is pressed against a developing roller or developer carrier by a preselected pressure, forming a nip for development. The developing device reduces irregular development ascribable to impurities caught at a regulating position assigned to the doctor roller more than a conventional developing device using a doctor blade as a regulating member.

Abstract: A developing device for an image forming apparatus of the present invention includes an image carrier performing endless movement while carrying a developer in the form of a layer thereon, and a regulating member for regulating the thickness of the layer Toner stored in the developing device is covered with an additive whose particle size is less than 2 &mgr;m. The regulating member is implemented as a doctor roller having a surface roughness Rz equal to or greater than the above particle size, but smaller than 2 &mgr;m. The doctor roller is pressed against a developing roller or developer carrier by a preselected pressure, forming a nip for development The developing device reduces irregular development ascribable to impurities caught at a regulating position assigned to the doctor roller more than a conventional developing device using a doctor blade as a regulating member.

Abstract: A development apparatus includes a development roller, a supplying roller, and a toner layer regulating member. The development roller contacts an image carrying member and develops an electrostatic latent image into a toner image on the image carrying member. The development roller may be made of aluminum and is rotatably mounted in the apparatus. The supplying roller supplies toner to the development roller. The toner layer regulating member regulates the toner to form a thin film on the development roller. The toner layer regulating member has a roller shape, a surface roughness Rz in a range of from 0.5 &mgr;m to 2 &mgr;m, and a dynamic friction coefficient in a range of from 0.1 to 0.8.

Abstract: In an optical scanner, a deflected light beam is reflected on a reflective image forming element and is converged as a light spot on a scanned face through an elongated lens to perform an optical scanning operation at an equal speed. The reflective image forming element has a reflecting face with rotation symmetry and converges a reflected light beam onto the scanned face in a main scan-corresponding direction. The elongated lens has a barrel type toroidal face as an incident face and has a normal toroidal face as a light emitting face. The elongated lens sets the scanned face and the forming position of a linear image to a substantially conjugate relation in a cross scan-corresponding direction in cooperation with the reflective image forming element. A conjugate magnification m.sub.0 in the conjugate relation of the reflective image forming element and the elongated lens with respect to an image height 0 of the light spot satisfies the following condition:1>m.sub.0 >0.35.

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: 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: 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 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 objective lens for an optical disk has a first lens group constructed by joining a negative meniscus lens, a biconvex lens, and a negative meniscus lens sequentially arranged from the side of a light source; and a second lens group constructed by a positive meniscus lens. The first and second lens groups are sequentially arranged from the side of the light source toward the side of the optical disk. A combined focal distance f of the entire lens system, a focal distance f.sub.1 of the first lens group, a radius r.sub.i (i=1 to 6) of curvature of an i-th lens face from the side of the light source, and a refractive index n.sub.j and an Abbe number .nu..sub.j (j=1 to 4) of a j-th lens from the side of the light source satisfy the following conditions,(I) 0.7.gtoreq.f.sup.2 /.vertline.r.sub.2 .multidot.r.sub.3 .vertline.<2.0,r.sub.2 >0,r.sub.3 <0(II) 2.0<[(n.sub.1 -1)+(n.sub.3 -1)]/(n.sub.2 -1)<3.0(III) 15<[(.nu..sub.2 -.nu..sub.1)+(.nu..sub.2 -.nu..sub.3)]<90and(IV) 2.0<(f.sub.