Mita Industrial Co., Ltd.

Kazuya Akura

Takahiro Wakikaido

Kenzo Okubo

Ken Yoshizuka

Masanori Itakiyo

A sheet size determining apparatus for use in a copying machine employing sheet containers capable of accommodating copy sheets of different sizes. The apparatus includes sensors for unidirectional detection of a dimension of sheets contained in the containers. An operator is induced by the apparatus to select the size of sheets actually contained in the containers, from possible sizes which, according to their orientation, would coincide with the dimension measured by the sensor. The size of the sheets to be utilized in a subsequent image forming operation thus is determined.

Sheet-size determining apparatus with selection inducing means

An exposure-scanning device comprising a guide member horizontally arranged, a scanning member slidably mounted to the guide member for performing an exposure-scanning operation upper and lower rollers rotatably mounted to the scanning member, both rollers vertically sandwiching the guide member, and an urging means provided at the scanning member for upwardly urging the lower roller to be constantly in contact with the guide member.

Exposure-scanning device

In a magnification adjusting mechanism, preparatory movement position calculating means utilizes a current position where an optical system is positioned at present, and a target position for the optical system which corresponds to an aimed magnification inputted by a magnification inputting means, to calculate a preparatory movement position between the current position and said target position, and optical system drive control means controls optical system driving means in such a manner that, when a magnification is inputted by the magnification inputting means, the optical system is moved to a preparatory movement position calculated by the preparatory movement position calculating means, and that, when a final magnification is determined, the optical system is moved to the target position, whereby even when a magnification is set again because it is unacceptable, the optical system is quickly moved to the destination.

Magnification adjusting mechanism

When a main body of an image forming apparatus is operated so that an image formation mode is set, a signal for determining which of several up-and-down type paper feeding devices is selected is applied from the main body of the image forming apparatus. In the selected paper feeding device, a selection signal detector determines that this selection signal is applied. If a paper detector determines that there are copy sheets whose number is at least a predetermined number, the paper deck is automatically raised by an up-and-down mechanism, even if the paper deck is in the lowered position. Even in the case where no up-and-down type paper feeding device is selected, if a timer measures time previously set, the paper deck may be automatically raised to a position where copy sheets can be fed. The up-and-down type paper feeding device according to the present invention has been constructed as described above and thus, an operator need not perform any operation so as to raise the paper deck from the lowered state. Consequently, there is provided an up-and-down type paper feeding device having good operability and capable of quickly and smoothly feeding copy sheets.

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Sakai, Japan

Kazuya Akura