摘要:
A developing device including first and second developing sleeves rotatable in the same direction and being disposed adjacent to each other and magnets unrotatable and fixedly mounted in the respective developing sleeves. The first magnet mounted within the first developing sleeve has a first magnetic pole slightly downstream of the position at which the first developing sleeve and the second developing sleeve are closest to each other with respect to the rotational direction of the first developing sleeve. The second magnet mounted within the second developing sleeve has a second magnetic pole slightly upstream of the above-described closest position with respect to the rotational direction of the second developing sleeve. A developer being transported by the first developing sleeve on the peripheral surface thereof is attracted by the second magnetic pole of the second developing sleeve in the region in which the first and second developing sleeves confront each other, thus being transferred easily from the peripheral surface of the first sleeve to that of the second sleeve. A developer being transported by the second developing sleeve on the peripheral surface thereof is attracted by the first magnetic pole of the first developing sleeve in the region in which both developing sleeves confront each other, thus being transferred easily from the peripheral surface of the second sleeve to that of the first sleeve. A repellent magnetic field is generated by the first and second magnetic poles between the region in which both developing sleeves confront each other.
摘要:
An electrostatic latent image developing device including a developing sleeve which is so provided as to confront a support member for supporting an electrostatic latent image, a toner reservoir for accommodating toner, which is formed, at its one portion, with an opening and a rotatable toner supply roller which is provided in the opening so as to confront the developing sleeve. The toner supply roller is formed, on its outer peripheral surface, with a plurality of first minute recesses and is further formed, in the first minute recesses, with a plurality of second minute recesses finer the first minute recesses.
摘要:
An electrophotographic copying apparatus which includes a thin sheet original transporting device having transporting rollers and disposed adjacent to a transparent platform for holding thick originals at the upper portion of the copying apparatus, and an image forming optical system moving device for moving the optical system from a scanning starting position for thick original copying to a stationary optical system position for thin sheet original copying in association with a change-over of operation from copying a thick original to copying a thin sheet original in order to eliminate disadvantages inherent in exposures in conventional copying apparatuses, and the distance between first and second reflecting mirrors of the optical system at the scanning starting position for copying thick originals is set to be less than that when the optical system is in the stationary position for reduction of the size of the copying apparatus.
摘要:
In an image forming apparatus accommodating a developing device, a developing roller 1 includes a magnet member 3 non-rotatably fixed and a sleeve 2 rotatably moved around the outer surface of the magnet member 3, powdery developers D held on the outer periphery of the sleeve 2 are brought into contact with a photosensitive member 10 to visualize an electrostatic latent image, and the magnet member 3 is provided with a magnetic pole portion N.sub.0 having first and second magnetic poles N.sub.1 and N.sub.2. The first and second magnetic poles N.sub.1 and N.sub.2 have the same polarities and are adjacent to each other and confront the photosensitive member 10. The powdery developers D include three developer parts, an upper developer D.sub.1, a middle developer D.sub.12 and a lower developer D.sub.2, which are successively retained on the outer surface of the sleeve 2 by the first and second magnetic poles N.sub.1 and N.sub.2. The upper developer D.sub.1 retained by the first magnetic pole N.sub.1 and the middle developer D.sub.12 retained by the middle portion between the first and second magnetic poles N.sub.1 and N.sub.2 are brought into contact with the photosensitive member, while the lower developer D.sub.2 retained by the second magnetic pole N.sub.2 is held out of contact with the photosensitive member.
摘要:
A toner supplying device for supplying toner to a developing device in an electrophotographic image forming apparatus comprises a toner hopper for containing and feeding new toner, a recycle device for introducing toner from a cleaner which collects residual toner on an electrostatic latent image carrying member to an outlet of the hopper or the vicinity thereof, a toner agitating chamber opposed to the outlet of the hopper and an outlet of the recycle device, a toner agitating member disposed in the toner agitating chamber, and a toner feeder for feeding the toner from the toner agitating chamber to the developing device.
摘要:
A developing device including a toner support member for supporting toner on its surface, which is so provided as to confront an electrostatic latent image support member and a regulation member for forming a thin layer of the toner on the toner support member, which includes a curved member for pressing the toner support member and a support member for supporting the curved member such that an area S of a space satifies an equation: 0
摘要:
A cleaning apparatus for cleaning a surface of a member by scraping residual particles off the surface. The apparatus has a blade with a forward edge in pressing contact with the surface, the blade being supported for movement from a position in which it is in pressing contact with the surface of the member to be cleaned to a position in which it is retracted from the surface of the member. A cleaning member for removing particles from the forward edge of the blade when the blade is in the contact position and is supported in pressing contact with the blade in the vicinity of the forward edge on the side of the blade facing the uncleaned area of the surface and on which particles are deposited when the blade is in the contact position in such a way as to cause the cleaning member to move with the blade during the movement of the blade from the contact position to the retracted position and, while remaining in pressing contact with the one side of the blade, to move from the vicinity of the forward edge to the forward edge during the movement of the blade toward the retracted position. Thus as the blade is retracted, the particles deposited on the forward edge of the blade are scraped off by the cleaning member moving in sliding pressing contact with the forward edge.
摘要:
A photocopying machine equipped with a variable magnification arrangement including a cassette containing large-size copy paper and positioned to permit lengthways transport of copy paper through the machine and a cassette containing small-size copy paper and positioned to permit sideways transport of copy paper through the machine. The cassettes comprise actuation elements which actuate different combinations of switches in a control circuit, which in response causes adjustment of positions of photocopying machine elements for production of photocopies of different magnifications and causes selective forwarding of copy paper of the required size from a cassette.