Abstract: An exposure device of an electrophotographic apparatus which includes a rotary polyhedral mirror for scanning a plurality of laser beams on a photosensitive body, a beam interval adjusting member for adjusting an interval between the laser beams, a rotating mechanism for rotating the beam interval adjusting member, and an optical path position deciding device disposed on the side of the rotary polyhedral mirror in a laser beam advancing direction at the time of adjustment of the laser beam interval, the beam interval adjusting member being rotated so that the optical paths of the laser beams are decided by the optical path position deciding device. The optical path position deciding device may include a plate-like member with boresights or a CCD sensor and a CRT display.

Abstract: A simple optical recorder which permits alignment of scanning positions of a plurality of laser beams with high accuracy and effects optical recording using the laser beams. The optical recorder is provided with a photosensitive drum which is scanned by a plurality of laser beams formed in rows at an inclined angle with respect to the direction of scan, a single photosensor for sensing each of the sweep positions of the laser beams, and a controller for controlling the scanning positions of the laser beams on the basis of a sensing result of the sensor. The controller is made up of an optical sensing signal separation circuit, synchronous clock generation circuits, FIFO memory circuit elements, and OR circuits.

Abstract: An electrophotographic apparatus system or an electrophotographic apparatus provided according to the present invention has the discrepancy of printing speed between tandem and single printing removed. The electrophotographic apparatus system or the electrophotographic apparatus is provided with printing speed changeover means 23a, 23b, 24 not only to select a printing speed applicable for the case where printing is effected with a plurality of electrophotographic apparatus A, B operatively linked together and another printing speed serviceable for the case where printing is implemented with each of plural electrophotographic apparatus put into separate run independently of one another, but also to shift the printing speeds from one to another, whereby the electrophotographic apparatus system or the electrophotographic apparatus may provide normal performance in each of the respective formations of printing.

Abstract: A developing device in an electrophotographic apparatus, wherein a pole c.sub.1 which is a delivering magnetic pole of the second developing roll for delivering the developer to the first developing roll and a pole d.sub.1 which is a receiving magnetic pole of the second developing roll for receiving the developer from the first developing roll are set so as to be the same in polarity, whereas a pole a.sub.2 which is a receiving magnetic pole of the first developing roll for receiving the developer from the second developing roll and a pole g.sub.2 which is a delivering magnetic pole of the first developing roll for delivering the developer to the second developing roll are set to be equal in polarity, wherein each of an angle between the poles c.sub.1 and d.sub.1 and an angle between the poles a.sub.2 and g.sub.2 is set so as to be in a range of from 70.degree. to 120.degree., and wherein the magnetic flux density of each of a reaction pole induced between the poles c.sub.1 and d.sub.

Abstract: Regulating parts E, F, of a developing agent regulating member 6, are arranged opposite to a photosensitive drum 7 with respect to a line connecting the centers of a developing roll 5 having a sleeve rotating in the direction of a and a developing roll 8 having a sleeve rotating in the direction of b. Holding members 10 which are slidable on the side plate of a developing apparatus are respectively provided at both ends of the developing agent regulating member. Developing agent is supplied from developing roll 5 to developing roll 8 through a back surface of the developing agent regulating member 6.

Abstract: A developing device for use in an electrophotographic apparatus includes a casing for storing a developer including a toner and a carrier therein; a photosensitive drum having a surface on which an electrostatic latent image is formed; a carrying magnetic roll for drawing up the developer stored in said casing; a developing magnetic roll for forming a magnetic brush out of the developer fed by the carrying magnetic roll to develop the electrostatic latent image; and a developer mixing chamber including an impeller interposed between the carrying and developing magnetic rolls, for mixing the toner and carrier contained in the developer with each other, which is drawn up by the carrying magnetic roll, to supply the mixed developer to the developing magnetic roll.

Abstract: A method of optically recording original information supplied from information generating device on an optical recording material in an optical recording apparatus, comprising the steps of: generating, from the original information, interpolating information which is to be interpolated in a sub-scanning direction of the optical recording material; and optically recording the interpolating information in the sub-scanning direction by a plurality of laser beams.

Abstract: A toner density detection method for an electrophotographic apparatus in which driving of a rotary roll provided at an outlet of a special vessel is continued for a predetermined period of time (e.g., several seconds) after the operation of the electrophotographic apparatus is stopped. All or substantially all of the developing agent is thus exhausted or removed from the special vessel after the electrophotographic apparatus is stopped, so that the true permeability of the developing agent can be detected by a permeability sensor when the operation of the electrophotographic apparatus is restarted. As a result, the toner density of the developing agent can be controlled and kept normal, so that the printing quality can be stabilized.

Abstract: A foreign matter removing mechanism for an electrophotographic printer, which includes: a sheet guide 2a, arranged between a photosensitive drum 1 and a tractor 9, for guiding a print sheet 3; and a foreign matter removing member 5 arranged so as to confront the sheet guide 2a through a predetermined gap 4 relative to the sheet guide 2a. In the foreign matter removing mechanism, a notch 11 is arranged on at least one confronting surface of the sheet guide 2a and the foreign matter removing member 5.