Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Minoru Seino

Akira Arimoto

Takeshi Mochizuki

Minoru Ohshima

Kenji Ishii

Susumu Saito

Junji Shirakawa

Yoshikane Matsumoto

Toshitaka Ogawa

Masayuki Ainoya

Tsukasa Onose

Makoto Kurosawa

Yasuo Kikuchi

Shigenobu Katagiri

Tsuneki Kobayashi

Osamu Namikawa

Koji Kato

Makoto Nakura

Yasushi Hashimoto

Yasuyuki Tsuji

Hiroshi Ueno

Masuo Kasai

Isamu Komatsu

Koji Doi

Akira Terakado

Kazutoshi Obara

Shuichi Morio

Susumu Saitoh

Hideki Ando

Yasushi Kimiwada

A transfer guide is provided which includes a guide member for guiding paper to a transfer point and a paper holding member using an electrically conductive member attached to the guide member by means of a spring member and disposed in the vicinity of a surface of a photosensitive drum, such that the gap becomes narrow for thin paper and the gap widens for thick paper in correspondence with the ream weight of the paper.

Electrophotographic apparatus having a paper holding member

In an electrophotographic printing apparatus, when the conveying speed of the timing roller (,) is Vt, the conveying speed of the register roller (,) is Vr, the peripheral speed of the photoreceptor drum (,) is V0, and the conveying speed of the conveying apparatus (,) is Vf, each speed is set to satisfy the relationship of Vf>V0&gE;Vr>Vt, and when a sheet deflection amount formed when the sheet comes into contact with the register roller, is &dgr;r, the sheet deflection amount at the photoreceptor drum entry section is &dgr;0, and the sheet length is Lp, each value is regulated so that the relationships of &dgr;r&gE;Lp ((Vr&minus;Vt)/Vt) and &dgr;0&gE;Lp ((Vf&minus;V0)/V0) are satisfied.

Electrophotographic printing apparatus

An image recording apparatus and a method of using the image recording apparatus. The image recording apparatus has a sheet sending path connecting a sheet supply section, an image forming section, and a sheet discharge section. A pull-in path branches from the sheet sending path, and a return path branches from the pull-in path to define a branch point. A first pair and a second pair of conveying rollers are provided on the pull-in path on respective sides of the branch point. The first pair and the second pair of conveying rollers are independently drivable in a forward direction and a reverse direction.

Image recording apparatus, and sheet conveying method thereof

An electrophotographic charger of the type in which a plurality of corona wires extend in the axial direction adjacent to and separated from the surface of a photosensitive drum in order to charge the surface. A plate-like etching grid is interposed between the corona wires and the drum to ensure the charge is uniformly placed on the drum. The grid is divided into a number of individual removable grids so that the distance between each grid and the adjacent corona wire, and the distance between each grid and the drum surface is substantially uniform.

Charger for electrophotography having a grid assembly

A beam position control apparatus in which a light beam is led into a light detector from a light generating source through a movable reflector and positioning of the light beam is performed by a servo control circuit for feeding a signal from the light detector back to the movable reflector, comprises: an oscillator for oscillating in response to an initializing signal and moving the movable reflector to move the beam onto the light detector; and a control switch for separating the oscillator and the movable reflector from each other in response to the signal from the light detector, the oscillator and the control switch being arranged in the servo control circuit.

Beam position control apparatus

An electrophotographic printer in which toner is printed and fused and the paper thereafter folded and stacked. To avoid toner stick a blower blows cooling air between adjacent folded sheets. The blower may be mounted on a horizotnally slidable paper guide. The stacker table may be lowered so that the top of the stack is maintained at the same height or the blower may be moved vertically in response to the output of a sensor detecting the top of the folded stack.

Paper cooling apparatus for an electrophotographic printer

A scanning apparatus for use in a laser beam printer or the like comprising a control means for varying the spacing between adjoining scanning beams of a plurality of laser beams, which further comprises a plurality of light sources, a means for changing intensity, including on/off states, of the beam from the light sources, and a rotating polygonal mirror for allowing the beams to scan the scanned plane in parallel, and is adapted, in accordance with the value of the pixel density of information to be recorded, such that, in the beam scanning direction, the area exposed to the beam is changed by changing the width of a beam intensity modulating pulse, and in the direction perpendicular to the beam scanning, the number of revolutions of the rotating polygonal mirror is changed.

Light beam scanning apparatus with controller for varying spacing

An optical scanner and method in which light beams from a plurality of sources are directed onto a medium to form a composite spot. The relative positions of the beams are detected and changed to change the diameter of the composite spot so that lines formed by such spots appear unbroken. The modulating times, intensities and number of sources of the beams can also be varied to provide a linear relation between the dither matrix and the picture element density.

Optical scanner and method for generating and detecting a composite dot

An electrophotographic device has a photosensitive element, an electrifier that forms a uniform electrostatic potential on the photosensitive element, and a light source for irradiating the photosensitive element to obtain an electrostatic latent image that has a reduced potential. A bias potential is applied to the photosensitive element after the latent image is formed, but before it is developed, so that the reduced potential of the latent image can be maintained at a constant level. With constant potentials existing on the photosensitive element, a printed image of high quality is obtained.

Electrophotographic device with controlled exposed potential

A printing mechanism is provided with a counter-balanced hammer bank such that the hammer bank and a counterweight are oppositely reciprocated by a pair of cams mounted on a vertically oriented cam shaft. Vibration of the printer even at high speed can be eliminated by completely dynamically balancing the system.

Dot printer

A printing mechanism is provided with a counter-balanced hammer bank such that the hammer bank and a counterweight are oppositely reciprocated by a pair of coaxial, identical, orthogonally oriented cams. Vibration of the printer even at high speed can be eliminated by completely dynamically balancing the system.

Growing community of inventors

Ibaraki, Japan

Minoru Seino