Ricoh Company, Ltd.

Toshiro Bando

Yutaka Hasegawa

Eiichi Katoh

Toshio Shiina

Tadayuki Sekiya

Koichi Asakura

Kiyoto Kozaiku

Masao Yaejima

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

An image recording apparatus for electrostatically forming a latent image representative of a document on a photoconductive element, or image carrier, and developing the latent image by a developer to produce a visible image. The apparatus is capable of controlling the density of an image to be recorded by adjusting the amount of illumination, toner density, bias voltage for development, etc. A target toner density is selected in response to the density of a toner image which is formed on the image carrier and has a relatively high density. The amount of illumination is adjusted in response to the density of a toner image also formed on the image carrier and having a relatively low density. Further, the bis voltage is selected on the basis of a ratio of the density of a reference density pattern and the actual density of a document.

Image recording apparatus capable of controlling image density

A control system for a copier, printer, facsimile apparatus or similar image forming apparatus which uses electrophotography controls, by digital control and by using a single signal line, a respective one of various control units for implementing image forming processes such as a grid power source for a main charger, a bias power source for development, a transfer charger power source, an exposing lamp regulator, and a fixing roller temperature controller.

Control system for an image forming apparatus

Alternating current electric power fed to a load is controlled to a target value using phase control. During a half cycle of the alternating current waveform, sampling of voltage and square calculation of the sampled value are repeated. During the remaining half cycle, average value calculation based on the result of the above calculation, root calculation and proportional calculation are implemented. Thus, the power control cycle is completed within one cycle of the alternating current waveform. By utilizing a plurality of sampling data, dropped data locating in a non-sampling period therebetween is obtained by interpolation. Sampling starts in synchronism with the energizing start-up phase.

Alternating current load power controller

An automatic original document supply device for electronic copying apparatus including a detection and control system, interposed between the original supply roller system and the original conveying and holding belt, which detects the passing of the trailing end of an original and produces a signal in response thereto for stopping the belt with the first original disposed in a predetermined illumination position and stopping the supply roller system with the next following original in a standby position. Over-running clutch arrangements are also provided in the supply roller system to permit the imposition of differential conveying speeds on the originals while passing the detection and control system, and to facilitate the reverse removal of an original from the supply roller system after positioning in the standby position.

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Yokohama, Japan

Toshiro Bando