Abstract: 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.

Abstract: An image forming apparatus according to the present invention includes a first processing device which processes in a normal mode for dynamically driving photoelectric detectors in groups so as to sequentially read detection signals from the photoelectric detectors in the groups, second processing device which process in a photoelectric detector check mode for driving a designated group of photoelectric detectors. Switching between processes by the processors is accomplished by a switching device. When the photoelectric detectors are checked, the photoelectric detector driving mode is switched from the normal mode to the photoelectric detector check mode by the switching device.

Abstract: 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.

Abstract: An image forming apparatus includes a memory having stored code data, code data input keys and a preheat changeover key for selectively switching the fixing device to a preheat mode or an operation ready mode, whereby the apparatus is permitted to operate when code data manually entered by the code data input keys are identical with code data previously stored in the memory. The image forming apparatus further includes entered code data release means responsive to operation of the preheat changeover key for switching the fixing device to the preheat mode, release entered code data whereby the apparatus is inhibited from operating. When the preheat key is pressed, the apparatus is switched to the preheat mode and, at the same time, the entered code data is released. Accordingly, the apparatus requires no dedicated button or key for releasing the entered code data, and may put, to practice use, the preheat changeover means which has been conventionally disposed.

Abstract: A display device in an image forming apparatus includes a liquid crystal display panel. The display panel selectively displays two types of modes, that is, a normal mode and a special mode. In the normal mode, a copy volume, a copying magnification, a copy density and the like are displayed. In the special mode, the contents for setting edit copies, the contents for setting composite copies and the like are displayed. According to the present invention, the special mode is displayed during only a constant time period in a case where each of special mode setting keys is operated. In the other cases, the display mode is automatically switched to the normal mode. More specifically, the normal mode which a user desires to know is usually displayed on the display panel. Only when the user sets the special mode, the special mode is displayed in response to an operation of each of the special mode setting keys. Accordingly, the display device has good operability.

Abstract: The present invention relates to a copying machine so composed that copying paper can be continuously fed from the stock section regardless of the movemental timing of the resist section, which has been so improved that the paper feeding speed or the paper feeding interval of the copying paper can be controlled in response to the relative scanning time of the optical system for a document.

Abstract: An apparatus for the formation of images having a body of the apparatus provided with a corona charger, in which a corona wire is strung along a charging opening of the corona charger. An image-forming device is installed in the body of the apparatus. The device is removable from the body of the apparatus along the corona wire. The apparatus further includes a cleaning device that is attached to the end portion of the image-forming device opposite to the direction in which the image-forming device is pulled out of the body of the apparatus. The cleaning device touching the corona wire through the charging opening when the image-forming device moves along the corona wire and separating from the corona wire when the image-forming device is installed into the body of the apparatus.

Abstract: A magnification selecting device which is capable of continuously varying magnifications by operating either UP or DOWN key and also slowing down the speed of varying mangifications only when these magnifications are in a position close to the predetermined magnification.

Abstract: An operation panel is provided in a copying machine wherein a print key is mounted on the right end part, various data displays are mounted on the center part, a set magnification display is formed at one end of these various data displays in the longitudinal direction thereof, and a set density display is formed at the other end thereof. A magnification setting key is mounted close to the set magnification display, and a density setting key is mounted close to the set density display. An original size display symbol is formed close to one side edge of the displays in the lateral direction, and a copy paper size display symbol is formed close to the other end thereof. Various function selecting keys are mounted somewhat apart from the various data displays. Before starting copying operation, display of the data that is to be set and entered by the operator is cleared. Display of set data is cleared during setting of the copy image density by automatic exposure.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of scanning.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of scanning.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of scanning.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of the scanning.