Hitachi Koki Co., Ltd.

Ricoh Company, Ltd.

Ricoh Printing Systems, Ltd.

Other

Hitachi Printing Solutions, Ltd.

Junshin Sakamoto

Susumu Saito

Takeshi Mochizuki

Shinichi Nakatsuka

Kenichi Kugai

Hiroshi Inenaga

Kenji Sugiura

Akira Arimoto

Shinichi Akatsu

Shigeru Shinohara

Makoto Kurosawa

Shun Suzuki

Masahide Tokuda

Katsuhiro Ono

Satoru Wada

Kazuo Sakaki

Takahiro Kikuchi

Akinori Tsushima

An image forming device includes a plurality of image formation units each configured to form an image of one of a plurality of colors, and a patch image transfer unit configured to control transfer conditions during transferring a patch group that is a pattern for detecting a position shift and formed on an intermediate transfer belt onto a secondary transfer belt. The patch image transfer unit is configured to transfer patches of at least single color for which a band of transfer efficiency is narrowest, of the patch group, onto the secondary transfer belt under transfer conditions for the color, and during transition to the transfer conditions for the color from other transfer conditions or during transition from the transfer conditions for the color to the other transfer conditions, patches of a color other than the color, of the patch group is transferred onto the secondary transfer belt.

Image forming device, position shift correction method, and recording medium

An image forming apparatus includes a transfer condition setting device to set a patch image transfer condition under which multiple patch images of respective component colors are transferred from an image bearer onto a recording medium conveyor. The transfer condition setting device sets a prescribed transfer condition that decreases a difference in transfer efficiency of toner between the respective component colors when the multiple patch images of respective component colors are transferred onto the recording medium conveyor below a difference in transfer efficiency of toner between the multiple component colors caused when transferred under the same transfer condition as a multicolor toner image is transferred onto a recording medium. A correcting device corrects an image forming condition to reduce an amount of misalignment caused in the multiple component colors of the multicolor toner image based on times of outputs from a patch image position sensor.

Apparatus, controller, and method of forming multicolor toner image

An image forming apparatus includes a patch forming unit configured to form a patch group containing patch subgroups arranged in a sub-scanning direction. Each of the patch subgroups contains a reference color patch and a color patch of a different color. The reference color patches are shifted from each other in a main-scanning direction. The color patches are shifted from each other in the main-scanning direction. The patch subgroups include reference patch subgroups in each of which the reference color patch covers over the color patch and detection patch subgroups in each of which at least part of the color patch does not overlap with the reference color patch. Center positions of non-overlapping portions of the color patches that do not overlap with the reference color patches in the main-scanning direction are located at substantially a same position in the patch group.

Image forming apparatus including a patch forming unit

According to an aspect of the present invention, there is provided an optical scanning apparatus including a light source, an optical unit, a first controller and a second controller. The light source emits a predetermined number of laser beams, the laser beams to be arranged in a sub-scanning direction on a recording medium. The optical unit simultaneously scans the laser beams in parallel on the recording medium. The first controller changes a dot size of the laser beams in a main scanning direction. The second controller changes the predetermined number.

Optical scanning apparatus

A semiconductor laser device including an edge-emitting type laser chip having at least three emitting points in one light emitting edge, a sub-mount mounted with the laser chip, and a heat sink bonded to the sub-mount through a solder layer. When R designates a linear expansion coefficient ratio of the heat sink to the sub-mount and D designates a distance between light emitting points at opposite ends in the light emitting edge of the laser chip, materials of the sub-mount and the heat sink and the distance D are set to satisfy the following relation:&#x2266;5.48&#xd7;A difference between stress acting on one laser element and another in the laser chip due to shrinkage of the heat sink when melted solder is cooled down is reduced so that a difference in light output characteristics between one light emitting point and another can be reduced.

Semiconductor laser device, light scanner, and image forming apparatus

A multi-beam image forming apparatus includes: first and second semiconductor laser arrays each having n laser elements; a multi-beam generation unit that generates 2n laser beams by synthesizing laser beams generated by the first and second semiconductor laser arrays; a beam detection unit that generates synchronous detection signals to obtain synchronous scanning of the respective laser beams; and a control unit. The beam detection unit includes first and second beam detection units disposed substantially at a same position in a main scanning direction and adjacently disposed in a sub-scanning direction. The n laser beams of the first and second semiconductor laser arrays are detected by the first and second beam detection unit, respectively. The control unit controls image formation start positions of the 2laser beams on the basis of the synchronous detection signals output from the first and the second beam detection units.

Multi-beam image forming apparatus

A color image forming device can minimize a registration error in a color image. A plurality of image forming units form the color image on a recording material. An image position detector detects a position of each patch pattern of a toner image formed on the recording material. A temperature detector detects a temperature inside the color image forming device. A registration error correction control part performs a first correcting operation and a second correcting operation, the first correcting operation for correcting a registration error of image in accordance with the position detection signal of the image position detector, the second correcting operation for correcting a registration error predicted by referring to a correction table, which includes a correction value previously determined in response to the temperature inside the color image forming device and an offset value, which is changed each time the first correcting operation is performed. The second correcting operation corrects the registration error by a value corresponding to the correction value plus or minus the offset value.

Color image forming device having a temperature detector

An image detector has an I/V converter for converting, into a voltage output., a current output as a result of a photoelectric element arranged in a traveling direction of an intermediate transfer belt having received light reflected from the intermediate transfer belt and light reflected from toner images formed on the intermediate transfer belt; a peak-hold unit for holding an output voltage into which the light reflected from the intermediate transfer belt has been converted by the I/V converter; and a computation unit for detecting a difference between the output voltage of the peak-hold unit and an output voltage into which the light reflected from the toner images of respective colors has been converted by the I/V converter.

Electrophotographic apparatus

In a simultaneous multibeam scanning system, composite beams are formed by using two semiconductor laser arrays each of which can singly output a plurality of beams. An optical system is enabled to scan beams of the number, which corresponds to the sum total of output beams of each of laser light sources, in a scanning plane. A stabilization control means for maintaining the interval between adjacent scanning beams at a uniform value is introduced into this optical system.

Optical scanning apparatus using a plurality of laser beams

The subject of the disclosed art is to prevent a short circuit between plural electrodes caused by soldering in the assembling process for a semiconductor laser element. The constitution for improving the subject is as follows. A semiconductor laser device comprises a semiconductor laser chip having a first electrode and a laser sustaining material, in which the laser sustaining material has electrodes and solder layers connected electrically therewith on the surface where the semiconductor laser chip is mounted, the first electrode of the semiconductor laser chip is connected with the solder layer of the laser sustaining material and at least the solder layer of the laser sustaining material extends from at least one end face in the longitudinal direction of an optical resonator of the semiconductor laser chip to the outside of the optical resonator.

Semiconductor laser array

A two-dimensional beam writing position detecting device for providing an optical system for scanning on a photoconductor by laser beams emitted from a semiconductor laser to form an electrostatic latent image and arranging a plurality of the laser beams in two dimensions and slantingly scanning each the laser beam for forming the electrostatic latent image on the photoconductor at a predetermined angle and detecting the laser beams for determining the first writing position on the photoconductor of the laser beams is characterized in that a longitudinal direction of a beam light receiving surface of the detecting device inclines at the substantially same angle as the slant scanning angle with respect to the perpendicular of a scanning direction of the plural beams.

Two-dimensional beam writing position detecting device and image forming apparatus using the detecting device

An electric photograph system for improving non-linearities of an exposing light intensity and an operating current at a low exposing level when performing analog printing operation. A range (saturable absorber) having a saturable absorbing characteristic is provided in a part of an optical path including a semiconductor laser as light source to improve the non-linearity of the operating current when the light intensity is weak. The saturable absorber may be made in the form of a non current injected area provided in a part of the semiconductor laser as the light source or a thin film layer provided partly in films coated on a facet of the semiconductor laser. Due to the provision of the saturable absorber, the light output power characteristic can exhibit its linearity in its low optical power range, the size of a printing dot can be arithmetically changed, and thus fine laser printing can be realized.

Electric photograph system

An annular groove is formed on the upper surface, or a surface C, of a rotor member. A surface D and a surface E of a rotor member, which are located closer to the center than the annular groove when radially viewed, are machined for correcting a dynamic unbalance of the rotor member. Therefore, a nonuniform deformation of the rotor member, which results from a centrifugal load and heat, which are due to the rotation of the rotor member, reaches the inside-diameter defining wall of the annular groove, but does not reach the outside-diameter defining wall of the annular groove since it is blocked by the annular groove.

Polygonal mirror device

A rotary sleeve 1 is integral with a rotary polygon mirror 14 forming a rotor section, one end portion of the rotary sleeve is formed into a magnet mounting section 15, on which a magnet yoke 3 and rotary magnets 4 are mounted. The rotary sleeve 1 has a bearing on its inner cylindrical surface 17 which is in the form of a through-hole.

Rotary polygon mirror motor

In a rotary polygon mirror device comprising a cylinder rotatably supported for holding a polygon mirror and a casing over the outer peripheral surface of said cylinder through a predetermined gap, the thermal expansion coefficient of said casing is set for 1.2-1.6 times as large as that of said cylinder.

Growing community of inventors

Ibaraki, Japan

Junshin Sakamoto