Ricoh Company, Ltd.

Eiichi Katoh

Hajime Oyama

Shin Hasegawa

Koichi Asakura

Hitoshi Hoshi

Masao Moriya

Yasushi Takahashi

Yutaka Hasegawa

Hiroshi Nishida

Toshiro Bando

Toshihiko Oda

Tsunehide Takahashi

Tatsuhiko Nakajima

A system includes: an apparatus information acquiring unit to acquire, from an apparatus, apparatus information regarding the apparatus; an analysis unit to make an analysis based on the acquired apparatus information; and a service determining unit to determine, on the basis of a result of the analysis, which service of a plurality of services should be provided for the apparatus, the services including a first service of additionally performing maintenance based on the result of the analysis when next other maintenance is performed for the apparatus.

System and service determination method

A disclosed maintenance management system includes an upper-limit information storage unit configured to store an upper limit of usage for each component identifier of a component, which upper limit is expressed by using an accumulated number of revolutions of a photoconductive drum in an image forming apparatus; a revolution number information acquiring unit configured to acquire a number of revolutions of the photoconductive drum used in the image forming apparatus; and an alarm output unit configured to calculate the accumulated number of revolutions of the used photoconductive drum, calculate a component service life predictive value by using the upper limit stored in the upper-limit information storage unit for each component identifier, and output an alarm including component information pertaining to the corresponding component identifier in the event that the component service life predictive value is less than or equal to a remainder day reference value.

Maintenance management system and image forming apparatus

An image density control method for an image forming apparatus determines the density of a toner image formed on a photoconductive element by a reflection type photosensor and, if the density is low, supplies a toner to a developing unit. A latent image representative of a reference pattern is electrostatically formed on the photoconductive element and then developed by a toner supplied from the developing unit. The supply of a toner to the developing unit is controlled on the basis of the outputs of the sensor associated with the area of the photoconductive element where the pattern image exists and a non-image area. A particular bias voltage is applied to the developing unit for each of the image area and non-image area.

Image density control method for an image forming apparatus for reducing

A toner end detecting method for an electrophotographic copier which allows the copier to operate even when a toner end condition is detected by accident or when a developing device included in the copier and being used is replaced with another storing a toner of the same color while a toner end condition is not reached. When the power source of the copier is turned off and then on or when the developing device is set on the copier, the method executes a recovery procedure.

Toner end detecting method for an electrophotographic copier

A fault diagnosis expert system for locating and eliminating sources of a machine trouble. The system comprises a storage part for storing an expert knowledge constructed in a hierarchical search tree structure in which cause-to-effect links connecting high-level effect events to low-level cause events are pre-defined and all possible low-level cause events are pre-enumerated for each high-level effect event, a user interface part for providing a user with questions and responses regarding the state of the machine trouble, an inference part for inferring a cause of the machine trouble with the expert knowledge and the user information, and an outputting part for allowing inference results from the inference part to be displayed for the user. The expert knowledge includes a cause candidate criterion pre-defined as an event used for selection of searching paths when the inference part makes a decision as to which path of the search tree should be traced back. The cause-to-effect links include an identifier indicative of a difference between self-dependency causes and other-dependency causes.

Fault diagnosis expert system

A control device for a copier is disclosure which detects an error of a drive system and which drives a photoconductive element. The device includes a motor and uses an output of a toner sensor responsive to the density of a toner image which is formed on the photoconductive element. The control device checks the drive system for an error by computing output data of the toner sensor appearing when the photoconductive element is rotated by the drive system and when it is held in a halted mode.

Control device for an image forming apparatus

A controller for controlling a bias power source associated with, for example, a developing unit of an electrophotographic copier such that a bias voltage to be applied to the developing unit for the adjustment of image density is variable in level. The controller includes a central processing unit in which a timer/event counter is built in for delivering a trigger pulse signal to trigger the power source. In order to produce a bias voltage associated with a desired density level, the trigger pulse signal is subjected to pulse width modulation control at a period which is far shorter than an output time consant of the power source.

Bias power source controller for an image forming apparatus

A copier with a toner supply device which includes a toner cartridge. Toner is supplied from the toner cartridge to a hopper section of a developing unit of the copier and from the toner hopper section to a developing section which includes a developing sleeve. The end of toner in the toner hopper is sensed by a toner end sensing mechanism. A switching device is provided which performs an on-off operation as an operation for supplying toner from a new or full toner cartridge proceeds. A controller controls the developing unit, toner end sensing mechanism and switching device to insure good reproductions even before or immediately after the supply of toner.

Copier with a toner supply device

In a relatively simple copier lacking a discharging unit which erases those portions of a photoconductive element which precede and follow an image, a control device reduces the amount of toner consumed and the amount of toner collected while preventing toner from being scattered around. For a surface portion of the photoconductive element which is associated with a trailing edge portion of a paper to which the image is to be transferred, a charging operation of a charger adapted to charge the photoconductive drum and a charging operation of a transfer charger are stopped. A bias voltage to be applied to a surface portion of the photoconductive element which follows the above-mentioned surface portion is increased.

Control device for a copier

A copier includes one motor for driving a photoconductive element unit, a developing unit, a fixing unit and other units, and another motor for driving an optical system. A clutch is interposed between the various units and the motor adapted to drive them. A device is provided for uncoupling the clutch for a predetermined period of time to interrupt the transmission of a drive force to the various units. The motor assigned to the units, clutch and drive force interrupting device are controlled such that the drive force interrupting device maintains the clutch uncoupled until the motor reaches a predetermined synchronous rotation speed after the start of rotation so as to interrupt the transmission of the drive force to the load, the clutch being coupled upon the lapse of the predetermined period of time to drive the load.

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Tokyo, Japan

Eiichi Katoh