Ricoh Company, Ltd.

Yoshihiro Nakashima

Hirobumi Yoshino

Akira Midorikawa

Tatsuo Tani

Tatsuo Hirono

Mitsutoyo Kikuno

Masayuki Shinada

Shigeru Muramatsu

Masashi Kuno

Masaji Ito

An image forming apparatus for uniformly charging the surface of a photoconductive element, exposing the charged surface of the photoconductive element imagewise to electrostatically form a latent image, and developing the latent image by a toner or similar developer. A linear equation is produced which is a reference representative of the input-output characteristic of a sensor responsive to the surface potential of the photoconductive element. The linear equation is used to calculate an accurate surface potential matching the output of the sensor. A bias voltage for development or similar image forming condition is controlled on the basis of the calculated surface potential.

Image forming apparatus using a linear equation to sense surface

An electrophotographic copier selectively operable with various kinds of toner automatically sets up optimum copy process conditions for any particular characteristic of toner to be used when a toner cartridge is replaced. The copy process conditions are changed upon the lapse of a predetermined delay time after the replacement of a toner cartridge. When an old toner cartridge mounted on the copier is replaced with a new toner cartridge which stores toner of a kind that should not be mixed with toner stored in the former, the copier identifies the new toner cartridge and produces an alarm to inhibit the replacement.

Electrophotographic copier with a capability of automatically setting up

A copying system comprises a first circuit for selecting a copying mode or a service program mode responsive to a manipulation of one or a plurality of keys, a second circuit for setting an operation mode to the service program mode when enabled by the first circuit, and a control device for automatically resetting one of a plurality of predetermined service program modes when the second circuit is disabled by the first circuit. Adjusting data for use in adjusting parts of the copying system in the service program mode are entered from the keys, and the predetermined service program modes are automatically reset when the operation mode is changed from the service program mode to the copying mode.

Copying system having copying and service program modes

A copier having eraser means for erasing needless ones of latent images which are electrostatically formed on a photoconductive element. A non-erase area is set up in consideration of a paper size, document size, trimming size and magnification. The non-erase size corresponds to a particular area where a paper size, a document size (with a magnification changed) and a trimming size (with a magnification changed) overlap each other. The non-erase area is displayed to facilitate confirmation by an operator. Latent images outside of the non-erase area are erased by the eraser means.

Copier capable of setting up an erase area on a photoconductive element

A copier with an image editing function which extracts desired areas of a plurality of documents in an analog fashion and allows them to be edited on a single transfer sheet. The copier includes an erasing device for selectively erasing an image provided on a photoconductive element, a detaining device for temporarily detaining a transfer sheet, an image inputting device for inputting an image of an original document, and a display device for displaying an input condition. Desired areas of documents are specified and edited with the aid of displays and then copied. Where the specified areas of the documents overlap each other, one of them having priority over the other or a selected one of them is copied. The number of areas to be edited is open to choice. The specified areas are entered through editing keys and usual ten keys. The erasing device is driven by a controller which is responsive to digital signals which are derived from position setting knobs associated with two perpendicular scales. Different colors are used to in correspondence with specified areas or documents. After copying, sheets are stocked in different positions on the basis of an edited content. An image portion inside or outside a specified area is selectable.

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Tokyo, Japan

Yoshihiro Nakashima