Ricoh Company, Ltd.

Mitsubishi Chemical Corporation

Matsushita Electric Industrial Co., Ltd.

Tohoku Ricoh Co., Ltd.

N.e. Chemcat Corporation

Mitsuo Suzuki

Yukio Itami

Kohei Okuyama

Satoshi Hirahara

Yoshihiro Takahashi

Kazushi Matsuura

Wataru Kashima

Hiroshi Igarashi

Yuki Satoh

Noriyuki Kadowaki

Hiroyuki Aikyo

Kunio Ikeda

Shuji Kondo

Wataru Ohtani

Takao Abe

Akio Kimura

Kiyoshi Shibuya

Masamichi Ueda

Yuzuru Kudo

Shushichi Yoshimura

Shinichi Kanamaru

A carbon black is provided which is useful as an electrocatalyst carrier. The carbon black has a DBP oil absorption of 170 to 300 cm/100 g, a specific surface area as measured by a BET method of 250 to 400 m/g, a primary particle diameter value of 10 to 17 nm, and a total volume of open pores at the surface which have a pore radius of 10 to 30 nm of 0.40 to 2.0 cm/g. The electrocatalyst can be used in electrochemical devices such as solid polymer electrolyte fuel cells.

Carbon black, electrocatalyst carrier formed from carbon black, and electrocatalyst and electrochemical device using carrier

A balance correcting method, a dynamic pressure bearing, and an optical scanning apparatus. For balance correction a method of attaching weight to the rotatable body and another method of partly removing the rotatable body are jointly used. At the time of a first balance correcting process step, a balance correction is performed by applying adhesive agent to a recess portion formed on a circular circumference of a polygon mirror or a recess portion constructed with a rotor flange. At the time of a second balance correcting process step, the polygon mirror is partly removed or the rotor flange is partly removed. The method can be applied to a dynamic pressure bearing capable of stabilizing a rotation balance and an optical scanning apparatus having a structure capable of not changing the direction of the reflection surface of the rotatable polygon mirror. The rotating shaft is supported in the radial direction by sucking air existing between the fixing shaft and the rotating shaft. In a dynamic pressure bearing, the rotating shaft is supported in a floating state from the above-mentioned fixing shaft.

Balance correcting method for a high-speed rotatable body, a dynamic pressure bearing, and an optical scanning apparatus utilizing the dynamic pressure bearing

An image forming apparatus with a DC brushless motor including a permanent magnet having n magnetized poles, where n is an even number, a rotatably held rotor on which the permanent magnet is fixed, a stator core having T-shaped pole shoes corresponding to the magnetic poles of the permanent magnet, windings fixed on the stator core and including a plurality of phases for selectively generating magnetic polarities in sequence, a driver circuit for switching conduction to the windings, and a rotating position detector for detecting a rotating position of the permanent magnet. The windings are divided into a plurality of winding groups for generating magnetic polarities in a plurality of the windings so as to produce a magnetic repellent force or a magnetic attractive force between all the magnetic poles of the permanent magnet and T-shaped pole shoes of the stator core associated with selected phases by the driver circuit based on a rotating position detected by the rotating position detector.

Direct-current brushless motor, and polygon scanner and image forming apparatus having the same and a method thereof

A direct-current (DC) brushless motor is provided for realizing an easy winding operation, a flat shape, effective utilization of a magnetic force, improved magnetic characteristics of a stator core, and a good rotation driving efficiency particularly at a higher rotational speed region. The DC brushless motor switches conduction to windings wound around a stator core fixedly disposed corresponding to a rotatable rotor on which a permanent magnet is fixed, to generate a rotating magnetic field which causes the rotor to rotate. The DC brushless motor includes a permanent magnet having n magnetized poles, where n is an even number, a rotatably held rotor on which the permanent magnet is fixed, a stator core having T-shaped pole shoes corresponding to the magnetic poles of the permanent magnet, windings fixed on the stator core and including a plurality of phases for selectively generating magnetic polarities in sequence, a driver circuit for switching conduction to the windings, and a rotating position detector for detecting a rotating position of the permanent magnet. The windings are divided into a plurality of winding groups for generating magnetic polarities in a plurality of the windings so as to produce a magnetic repellent force or a magnetic attractive force between all the magnetic poles of the permanent magnet and T-shaped pole shoes of the stator core associated with selected phases by the driver circuit based on a rotating position detected by the rotating position detector.

A motor drive apparatus for driving a motor with power derived from a main power source, including a signal input device configured to input a start signal and a stop signal to initiate starting and stopping of the motor; a voltage regulator configured to output regulated electric power to the motor; and a semiconductor switching device disposed between the main power source and the voltage regulator, coupled to the signal input device, and configured to switch electric power from the main power source to the voltage regulator in accordance with the start signal input from the signal input device, and to shut off the electric power to the voltage regulator in accordance with the stop signal input from the signal input device.

Motor drive apparatus and method

A carbon black having a ratio of a maximum absorbance in a range of 1800 to 1670 cm.sup.-1 to a maximum absorbance in a range of 1670 to 1500 cm.sup.-1 of not less than 0.65 on condition that a straight line interconnecting the absorbances at 1805 cm.sup.-1 and 900 cm.sup.-1 is taken as a base line in an absorbance chart of infrared absorption spectrum.

Carbon black

Electric double-layer capacitor are disclosed having a non-aqueous solvent electrolyte; and a pair of polarized electrodes as positive and negative electrodes. These polarized electrodes have a rest potential nearly central between a substantial decomposition initiation voltage of the electrolyte on an oxidation or high-potential side and a substantial decomposition initiation voltage of the electrolyte on a reduction or low-potential side.

Electric double-layer capacitor

Active carbon of which the pore size distribution as measured by a Cranston-Inkley method has a peak within each of ranges of from 10 to 20 .ANG. and from 20 to 100 .ANG..

Active carbon and process for its production

A rotor includes a hollow rotating shaft that is supported in a non-contact state by a radial self acting air bearing. The rotor also includes a contacting portion for positioning a rotating member in a rotating shaft direction that contacts with the rotating member from the rotating shaft direction. An engaging portion is included for positioning the rotating member in a direction perpendicular to the rotating shaft direction that engages with an inner surface of the rotating member. A holding portion is formed either in plural portions in a peripheral direction or as a single integrated portion that extends in the peripheral direction near the rotating member that is positioned by the contacting portion and the engaging portion, and that presses the rotating member from an opposite side of the contacting portion by deformation of one portion or a whole portion of the holding portion, and positions and holds the rotating member.

Rotor and polygon scanner that incorporates the rotor

The present invention relates to an activated carbon comprising an activated carbon particle and titanium dioxide fine particles present at least on the surface thereof, which activated carbon contains substantially no carbon precursor on the surface thereof and has the lightness L value thereof of not more than 50.

Activated carbon and process for producing the same

An oscillator in which organic substances derived from an active element fixing adhesive do not deposit on an oscillating element and in which when the active element or the oscillating element is damaged, other good parts that are not defective can be reused. In the oscillator, an active element 2 is mounted inside a first container 1 whose upper surface is opened, and not only the opening of the first container 1 is closed by an oscillating unit 3 having an oscillating element 6 incorporated therein, but also the oscillating unit 3 is attached onto the opening of the first container 1, so that second connecting electrodes 11a to 11d of a second container 5 of the oscillating unit 3 are electrically connected to first connecting electrodes 14a to 14d of the first container 1. As a result of this construction, the oscillating element and the active element can be accommodated in separate containers, which not only prevents organic substances derived from an active element fixing adhesive from being deposited on the oscillating element, but also parts that are not defective can be reused only by separating the first container from the second container if the active element or the oscillating element is damaged.

Reference frequency source oscillator formed from first and second

A dynamic pressure pneumatic bearing device has a groove for generating a dynamic pressure and formed on an inner circumferential face of a rotating shaft or an outer circumferential face of a fixed shaft; each of these shafts being formed by an aluminum alloy; and a wear resisting film formed on each of the inner circumferential face and the outer circumferential face. Another dynamic pressure pneumatic bearing device is constructed by a rotating shaft having a cylindrical hollow and a fixed shaft inserted into this hollow. The fixed shaft has a bearing face opposed to an inner circumferential face of the rotating shaft and separated from this inner circumferential face with a predetermined clearance. Herringbone grooves for generating a dynamic pressure and recessed portions having the same depth as the herringbone grooves are formed on the bearing face.

Dynamic pressure pneumatic bearing device and manufacturing method

The current invention is directed to a high-speed optical deflector which includes a brushless motor operating in a high-temperature environment. The brushless motor components include rotatable parts made of various materials whose thermal expansion coefficients significantly vary. These rotational components include a steel rotor flange, a magnet rotor, and an aluminum shaft. To substantially eliminate rotational imbalance or vibration caused by the thermal expansion, the above described components are fixed with a certain adhesive which prevents these components from causing the rotational imbalance. A certain heat-resistant adhesive provides a sufficient structural strength to substantially minimize a rotational imbalance caused by the thermally expanding components in an operating temperature range.

Method of and device using adhesively connected parts for preventing

A closed type polygon scanner has a housing, a rotor which is rotatively supported to a rotating shaft fixed to the housing and which includes a polygon mirror, a motor which generates a magnetic force to the rotor and rotates the rotor, and a cover. The cover includes an outer peripheral portion fixed to an outer peripheral portion of the housing, and covers the rotor together with the housing. An opening is formed at a predetermined portion in the cover facing a mirror surface of the polygon mirror through which a laser beam passes, and a window member is fixed to the opening in closed state. An inner peripheral surface of the cover facing the mirror surface of the polygon mirror is formed cylindrically and almost coaxially to a rotating axis of the rotating shaft, and a width in the rotating axis direction of the opening is set to a predetermined width relative to a width of the polygon mirror so that turbulent air generated around the polygon mirror is reduced.

Closed type polygon scanner

A device for driving a DC motor includes a velocity control circuit generating a velocity control signal, a modulation circuit deriving a velocity control pulse signal having a pulse width modulated by the velocity control signal, a switching circuit, and a current-flow switching circuit. The switching circuit includes field effect transistors performing a switching operation, and a capacitor coupled between a power supply terminal and a reference potential. The capacitor absorbs a counter current caused in driving coils of the DC motor due to the switching operation.

Growing community of inventors

Yokohama, Japan

Mitsuo Suzuki