EP0033647A2 - Dispositif de nettoyage pour appareil de tirage électrostatique - Google Patents

Dispositif de nettoyage pour appareil de tirage électrostatique Download PDF

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Publication number
EP0033647A2
EP0033647A2 EP81300404A EP81300404A EP0033647A2 EP 0033647 A2 EP0033647 A2 EP 0033647A2 EP 81300404 A EP81300404 A EP 81300404A EP 81300404 A EP81300404 A EP 81300404A EP 0033647 A2 EP0033647 A2 EP 0033647A2
Authority
EP
European Patent Office
Prior art keywords
developing
magnetic
developing sleeve
toner
copying apparatus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP81300404A
Other languages
German (de)
English (en)
Other versions
EP0033647A3 (en
EP0033647B1 (fr
Inventor
Ryutaro Yamagata
Nobuhiko Kozuka
Hitoshi Nishihama
Shigeo Koyama
Kazutada Sakai
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kyocera Mita Industrial Co Ltd
Original Assignee
Mita Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP1181180A external-priority patent/JPS56107274A/ja
Priority claimed from JP1980012037U external-priority patent/JPS6333225Y2/ja
Priority claimed from JP1980012034U external-priority patent/JPS6328435Y2/ja
Priority claimed from JP1980012036U external-priority patent/JPS6328436Y2/ja
Priority claimed from JP1203580U external-priority patent/JPS56113346U/ja
Priority claimed from JP1181080A external-priority patent/JPS56107280A/ja
Priority to DE8383109210T priority Critical patent/DE3176117D1/de
Application filed by Mita Industrial Co Ltd filed Critical Mita Industrial Co Ltd
Publication of EP0033647A2 publication Critical patent/EP0033647A2/fr
Publication of EP0033647A3 publication Critical patent/EP0033647A3/en
Application granted granted Critical
Publication of EP0033647B1 publication Critical patent/EP0033647B1/fr
Expired legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • G03G21/0005—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge for removing solid developer or debris from the electrographic recording medium
    • G03G21/0035—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge for removing solid developer or debris from the electrographic recording medium using a brush; Details of cleaning brushes, e.g. fibre density
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • G03G21/0005—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge for removing solid developer or debris from the electrographic recording medium

Definitions

  • the present invention Q enerally relates to a transfer type electrostatic copying apparatus, and more particularly, to a cleaning divice which cleans off developing material remaining on a photosensitive material or photoreceptor by a magnetic brush.
  • the invention further relates to a developing device for use in an electrostatic copying apparatus and more particularly, to a developing device of this kind which is so arranged that, by supplying mono-component magnetizable toner onto a developing sleeve which is driven'for rotation, magnetic brush is formed on the developing sleeve by the action of a stationary permanent magnet provided within said developing sleeve, while the bristle length of the magnetic brush is restricted by a bristle cutting member.
  • the developing apparatus which is arranged to form the magnetic brush by supplying the mono-component magnetizable toner onto the peripheral surface of the developing sleeve to he rotated around a stationary permanent magnet
  • the surplus mono-component magnetizable toner of the magnetic brush cut off by the bristle cutting member for restricting the bristle length tends to stay stationarily at the upstream side of the bristle cutting member along the rotational direc- t ion of the developing sleeve, thereby to cause the mono-component magnetizable toner to be solidified, and thus, the undesirable blocking phenomenon is liable to take place.
  • the mono-component magnetizable toner is blocked by the solidified mono-component magnetizable toner and can not be transported up to the developing position, thus making it impossible to effect the developing.
  • the remaining mono-component magnetizable toner which has not been used for the development at the developing position is continuously rotated as it is attracted onto the predetermined position of the developing sleeve, thereby to be magnetized by the powerful magnetizing action from the permanent magnet, with corresponding reduction of fluidity of the mono-component magnetizable toner. Accordingly, the state of brush bristles of the magnetic brush can be maintained constant, thus resulting in the irregular development through reduction of the developing efficiency.
  • another object of the invention is to provide an improved developing apparatus for use in an electrostatic copying apparatus which is capable of preventing the blocking phenomenon of the mono-component magnetizable toner by a bristle cutting memeber, and also capable of maintaining the proper fluidity of the mono-component magnetizable toner and also uniformity in the state of formation of the brush bristles of the magnetic brush, through solution of the technical problems as described above.
  • the invention still further relates to a presence detection device of a developing material in the developing device for use in an electrostatic copying apparatus and more particularly, to a presence detection device of the developing material in the developing device arranged to form magnetic brush by supplying developing material onto the peripheral surface of a develping sleeve provided therein with a stationary permanent magnet and driven for rotation.
  • an another object of the invention is to provide an unexpensive presence detection device with simple construction for use in a developing device of an electrostatic copying apparatus.
  • a cleaning device for a transfer type electrostatic copying apparatus which comprises magnetic brush cleaning means for cleaning off a magnetizable toner remaining of a photosensitive material after transfer, comprising : (.a) a hair brush roller disposed between the magnetic brush cleaning means and a transfer zone, and having a construction that a hair brush is filled on a peripheral surface of a cylindrical mamber of light transmitting material and driven for rotation and is in contact with the photosensitive material; and (b) a charge eraser lamp secured within the cylindrical member.
  • the photoreceptor since the developing material remaining on the photosensitive material or photoreceptor is deviated or shifted in the positive by the hair brush roller before the cleaning process by the magnetic brush, while the portions from which the developing material has been removed by the shifting are subjected to the light projec- ti on by the charge eraser lamp for erasing the charge thereat, the photoreceptor is almost completely erased with respect to the charge, and consequently, the cleaning efficiency is markedly improved owing to the facilitated removal of the developing material through cleaning by the magnetic brush.
  • a rotary shaft disposed upstream of a rotational direction of the magnetic brush with respect to the res- trictin q member, and driven to totate around an axial line parallel with a rotational axial line of the magne- ti c brush
  • transporting means of non-magnetic material for transporting a remaing developing material restricted bv the restricting member in a rotation of the transporting means and secured to the rotary shaft at a right angle
  • a developing material receptacle for receiving the developing material falling from the transporting means when the transporting means rotates downwardly having an opening facing upwardly on the opposite side of the magnetic brush with respect to the rotary shaft.
  • the developing material removed by the magnetic brush is transported on the transport member driven for rotation so as to be brought to the position above the developing material receptacle container, and therefore, the removed developing material can be positively fed into the developing material receptacle container.
  • a switching means for alternating a switching mode in accordance with the weight of the developing material stored in a developing material receptacle when the weight is reached a predetermined value. Since there is provided the switching means whose state of switching is altered by the weight of developing material when the developing material accumulated in the developing material receptacle container has reached a preliminarily set weight, it is readily detected that the developing material receptacle container has been filled up by the developing material, and overflowing of the developing material from the developing material receptacle container may be advantageously prevented.
  • an improved developina device for an electrostatic copvina apparatus in which a permanent magnet havina a pluraritv of magnetic poles maanetized at each equal space in a peripheral direction of the permanent magnet is coaxially secured in a hollow developing sleeve made of non-magnetic material and driven to rotate, a one-component magnetizable toner is supplied on the developing sleeve so as form a magnetic brush, and a bristle cutting member restricts a length of the magnetic brush, characterized in that there is provided a blade member made of non-magnetic material, disposed upstream along the rotational direction of the developing sleeve at the vicinity of the bristle cutting member, inclining to separate from the peripheral surface of the developing sleeve downstream along the rotational direction, and contacting with the peripheral surface of the developing sleeve.
  • the neighboring magnetic poles are directed to have alternately opposite polar orientation, the magnetic poles formed at a magnetized posotion facing the bristle cutting member and a magnetized position contacting with the blade member are neighboring and opposite polarization to each other, the blade member has aconstruction so as to allow the one-component magnetizable toner pass at about central position between the magnetic pole facing the bristle cutting member and the magnetic pole contacting with the blade member.
  • the magnetized position contacting with the blade member has a pair of neighboring magnetic poles with the same polarization.
  • a single of magnetized position of the permanent magnet has a pair of neighboing magnetic poles with the same polarization in an area from a developing zone to the blade member along the rotational direction of the developing sleeve.
  • a plurality of magnetized positions of the parmanent magnet has a pair of neighboring magnetic poles with the same polarization in an area from the developing zone to a blac e member alona the rotary direction of the developina direction.
  • the blade member which is in sliding contact with the peripheral surface of the developing sleeve is provided at the upstream side immediately before the bristle cutting member along the rotational direction of the developing sleeve, the mono-component magnetizable toner is flowing at all times at the upstream side of the bristle cutting member, and accordingly, the undesirable blocking phenomenon of the mono-component magnetizable toner by the bristle cutting member may be advantageously prevented.
  • the mono-component magnetizable toner on the developing sleeve is once separated from the peripheral surface of the developing sleeve by the blade member at every one rotation of the developing sleeve, the proper fluidity of the mono-component magnetizable toner can be positively achieved, with the state of bristle formation of the magnetic brush being uniformly maintained.
  • the developing material is supplied onto a developing roller having the developing sleeve disposed in the vicinity of a photosensitive material, there are further provided, (f) a storage container having a bottom formed in an arcuate-shape and extending downwardly, and having a supply port opening for supply the developing material onto a peripheral surface of the developing roller, (g) a rotary shaft provided rotatably around the center of the arcuate bottom of the storage container, ( h ) a stirring and feeding means for stirring the developing material in the storage container to supply to the supply port, and extending radially from the rotary shaft to the vicinity of the inner surface of the bottom of the straqe container, (i) a ratchet wheel secured to the rotary shaft axially, (j) a rocking lever having one end supported by a pin p aral led to the rotary shaft, having the other end engaging to associate with the developing roller, and swingable around the pin in accordance with the rotational motion of the developing roller, and (k) a claw
  • a presence-detecting device for detecting the developing material comprising; (1) a detecting member made of non-magnetic material, swingable about a horizontal axis in a vertical plane with aspect to an axis of the developing sleeve between a first angular position corresponding to a substantially central position of neighboring N pole and S pole of the permanent magnet at a vicinity of the developing sleeve in accordance with the depressing force of the maqnetizable toner attracted by the permanent magnet and a second angular position far from the developing sleeve in accordance with the own weight of the detectiong member against the depressing force of the developing material, disposed between the developing sleeve and an supply port of a developing material storaae container for storing the developing material and for supplying the developing material to the developing sleeve,(m) an engaging member swingable about a hprizontal axis formed integrally the detecting member, and (n) switching means having an actuator engaging with the engaging member
  • the developing material supplied from the storage container is depressed as it is attracted by the permanent magnet so that the detecting member is subjected to the angular displacement between the first angular displacement position and the second angular displacement position, with the switching state of the switch means being altered according to the angular displacement of said detecting member, and therefore, presence or absence of the developing material on the peripheral surface of the developing sleeve can be readily detected. Furthermore, at the first angular displacement position, since the detecting member is positioned at approximately the central portion between the N pole and S pole, said detecting member is readily subjected to the angular displacement even by the slight depressing force by the developing material.
  • Fig. 1 a schematic side sectional view of a transfer type electrostatic copying machine according to one preferred embodiment of the invention.
  • the copying apparatus of Fig. 1 includes a photosensitive or photoreceptor drum 4 having a photcsensitive material or photoreceptor 3 provided on the entire peripheral surface of a drum 2, and rotatably mounted at approximately a central portion of a machine housing 1.
  • the copy paper sheets stacked and accommodated in a paper feeding cassette 17 are fed, one sheet by one sheet, by a paper feeding roller 18 from the paper feeding cassette 17.
  • the copy paper sheets are transported by a pair of feeding and transporting rollers 21 and 22 through upper and lower guide plates 19 and 20 in pair.
  • the copy paper sheet fed into a transfer region 25 through another pair of upper and lower guide plates 23 and 24 is caused to closely adhere to the surface of the photoreceptor drum 4 confronting the transfer corona .charger 8.
  • the copy paper sheet After the transfer process, the copy paper sheet is held, at its one edge in the direction of width thereof, between a separating roller 26 and an auxiliary separating roller 27 so as to be peeled off the surface of the photoreceptor drum 4, and is fed into a heat fixing device 31 having a pair of heat fixing rollers 29 and 30 through a guide plate 28. In this heat fixing device 31, the toner image on the surface of the copy paper sheet is fixed. After the fixing process as described above, the copy paper sheet is discharged onto a copy paper tray (not shown) through a pair of discharging rollers 32 and 33.
  • a sprocket wheel 36 around which a first endless chain 37 is directed or passed.
  • the chain 37 is sequentially passed around a sprocket wheel 38, a sprocket wheel 39 coupled to the feeding and transporting roller 22 and a sprocket wheel 40 connected to the copy paper feeding roller 18 along its running direction indicated by the arrow.
  • a second endless chain 41 is passed around another sprocket wheel (not shown) secured to the output shaft 35 so as to be one unit with the sprocket wheel 36.
  • the chain 41 is sequentially passed around sprocket wheels 42 and 43, two sprocket wheels 44 and 45 for driving the original carrie--P 11, and sprocket wheels 46 and 47 along its running direction indicated by the arrow.
  • the gear (not shown) to be rotated as one unit with the sprocket wheel 43 is engaged with a gear 48 connected to the heat fixing roller 29.
  • the sprocket wheel 44 is connected to a gear 49 through a clutch which is not shown, while the sprocket wheel 45 is coupled to a gear 50 and a pulley 51 through a clutch which is not shown, with the gears 49 and 50 being in mesh with each other.
  • a wire 160 connected, at its one end, to the right side end of the original carrier 11 in Fig.
  • a gear 52 mounted on the same shaft as the sprocket wheel 46 is connected to a gear 57 through gears 53, 54, 55 and 56.
  • the gear 56 is secured to a rotary shaft 58 of the cleaning device 9, while the gear 57 is concentrically fixed to a sleeve 120 of the cleaning device 9.
  • a gear 60 to be rotated as one unit with the sprocket wheel 47 is connected through a gear 61 to a gear 62 which is coupled to a cylindrical member 128 of the cleaning device 9. Meanwhile, the gear 60 is connected to a near 64 associated with the separating roller 26 through a gear 63.
  • the developina device 7 further includes a developing roller 72 disposed in the vicinity of the photoreceptor 3 in a direction parallel with the axis of the photoreceptor drum 4, a storage container 73 for storing therein the mono-component magnetizable toner, as a developing material, a stirring and feeding means 74 operably housed in the storage container 73 for stirring the mono-component magnetizable toner therein and also for supplying the mono-component magnetizable toner onto the developing roller 72, a bristle cutting member 75 for restricting the length of the magnetic brush bristles to be formed on the peripheral surface of the developing roller 72, and a blade member 76 for once separating the magnetic brush from the peripheral surface of the developing roller 72 so as to bring it towards the bristle cutting member 76.
  • the developing roller 72 has a permanent magnet member 77 concentrically secured in the hollow developing sleeve 71 made of non-magnetizable material.
  • One end of the permanent magnet member 77 extends through corresponding one end of the devel- o p ing sleeve 71 through a bearing 82, and is fixed to a support member 81 secured to a front side plate 79 of a frame 78 of the developing device 7 .
  • the other end of the developing sleeve 71 extends through a rear side plate 80 of the frame 78 through a bearing 83, and is fixed with the aear 69.
  • the other end of the permanent magnet member 77 is supported by the developing sleeve 71 through a bearing 84.
  • the permanent magnet member 77 is magnetized by a plurality of magnetic poles circumferentially directed at equal intervals, with neighboring magnetic poles being directed to have alternately opposite polar orientation. As described with reference to Fig.
  • the mono-component magnetizable toner supplied from the storage container 73 forms the magnetic brush on the developing sleeve 71.
  • the peripheral surface of the photoreceptor 3 is rubbed against the magnetic brush, whereby the electrostatic latent image on the photoreceptor 3 is developed into the visible image.
  • the storage container 73 includes an arcuate portion 87 having an arcuate shape in a vertical plane and extending in a direction parallel to the developing roller 72, and a conical portion 88 connected to the upper portion of the arcuate portion 87 at the side opposite to the developing roller 72 with respect to the central axis of the arcuate portion 87 and open upwardly as shown, and is formed into one unit with a frame 78.
  • the arcuate portion 87 is formed with a supply port ' 89 for supplying the mono-component magnetizable toner onto the developing sleeve 72.
  • the above supply port 89 is defined above the developing roller 72 so that the mono-component magnetizable toner may be supplied onto the peripheral surface of the developing roller 72.
  • the stirring and supplying means 74 further includes a rotary shaft 92 journalled to the front and rear side plates 79 and 80 on the central axis of the arcuate portion 87 through bearings 90 and 91, a stirring and supplying member 93 integrally provided with the rotary shaft 92, a ratchet wheel 94 secured to one end of the rotary shaft 92, a rocking lever 96 pivotally supported at its end by a pin 95 provided on the rear side plate 80 and connected, at the other end thereof, to the gear 69 for rocking motion about said pin 95 following the rotation of the gear 69, a claw member 98 pivotally connected to an intermediate portion of the rocking lever 96 by a pin 97 for engagement with the teeth of the ratchet wheel 94, and a spring 99 which urges the claw member 98 towards the ratchet wheel 94.
  • the stirrina and feedin Q member 93 extends in parallel with and adjacent to an inner wall 87a of the arcuate portion 87 between the front and rear side walls 79 and 80, with its opposite end portions being bent at right angles so as to be pressed into the rotary shaft 92 for securing.
  • a pin 100 is provided, while an elongated opening 101 is formed at the other end of the rocking lever 96 for engagement with the pin 100.
  • the spring 99 is provided to surround the pin 97, with one end of the spring 99 being engaged with the rocking lever 96 and the other end thereof, with the claw member 98. By the spring force of this spring 99, the claw member 98 is urged about the pin 97 in the direction shown by the arrow 102.
  • the rocking lever 96 is provided with a stopper piece 103 for restricting the rotation of the claw member 98.
  • the stirring and supply member 93 is rotated about the rotary shaft 92 following the rotational movement of the developing sleeve 71, whereby the mono-component magnetizable toner in the arcuate portion 87 is agitated, and is also brought to the supply port 89 through a longitudial portion 93a of the stirring and supply member 93.
  • the mono-component magnetizable toner thus brought to the supply port 89 is fed from said supply port 89 onto the peripheral surface of the developing sleeve 71.
  • a reverse rotation preventing member 105 which is arranaed to contact with the teeth of the ratchet wheel 94 at the downstream side of the rotational direction 104.
  • the maanetic bruch on the developing sleeve 71 is blocked by the mono-component maanetizable toner subjected to the blockin q so as not to be fed to the develo p ina position 86, thus making it impossible to effect the developing at the portion.
  • the base portion of the magnetic brush does not contribute to the development, and remains on the peripheral surface of the developing sleeve 71 as it is so as to continue rotation together with the developing sleeve 71. Accordingly, the toner on the developing sleeve 71 is lowered in its fluidity, with alteration in the state of formation of the brush bristles, and thus, the developing efficiency is correspondingly reduced.
  • the blade member 76 is provided at the upstream side of the bristle cutting member 75 along the rotational direction 85.
  • the blade member 76 described above is so inclined as to be spaced from the developing sleeve 71 towards the downstream side along the rotational direction 85, with its base portion 76a being secured to the frame 78, and the free end 76b thereof is arranged to be slid on the developing sleeve 71 over its entire length.
  • the position thereof corresponding to the bristle cutting member 75 and the position which is in sliding contact with the free end 76b of the blade member 76 are magnetized by the neighboring magnetic poles having mutually different polar orientation.
  • the position correspondinq to the bristle cutting member 75 is magnetized with the N pole, while the position corresponding to the blade member 76 is magnetized with S pole.
  • the passing holes 106 are each formed at approximately the central portion between the N pole and S pole as described earlier, the magnetic attracting force exerting on the mono-component magnetizable toner at the passing holes 106 is directed in a direction normal to the magnetic lines of force, i.e. in a radial inner direction of the developing sleeve 71. Accordingly, the toner is readily supplied towards the inner side of the radial direction of the developing sleeve 71 from the passing holes 106 through the above described magnetic attracting force.
  • the detecting member 111 extends vertically via a through-opening 114 defined in the frame 78 for restricting the range of angular displacement of said detecting member 111, while the engaging member 112 is disposed above the through-opening 114.
  • One end portion of the engaging member 112 is bent at right angles at the outer side of the side plate 79, and the bent portion 112a thus formed is engaged with an actuator 115 of the microswitch 113, which is coupled, for example, to a toner replenishing instruction means such as a pilot lamp or the like (not shown) .
  • the detecting member 111 is rotated in the direction approaching the developing roller 72 through depression by the mono-component magnetizable toner as shown by the imaginary line in Fig. 3.
  • the free end of the detecting member 111 corresponds to the approximately central position of the N pole and S pole of the permanent magnetic member 77, whereby the detecting member 111 comes to be readily subjected to the angular displacement through a slight depressing force by the mono-component magnetizable toner.
  • the engaging member 112 is also subjected to the angular displacement, according to which the microswitch 113 is cut off. Accordingly, the pilot lamp as described earlier is kept de-energized at the first angular displacement position 116.
  • the microswitch 113 is rendered conductive, with consequent illumination of the pilot lamp, and thus, it is indicated that the toner in the storage container 73 has been used up, with simultaneous absence of the toner on the peripheral surface of the developing sleeve 71.
  • the detecting member 111 and engaging member 112 should preferably be made to be light in weight as far as practicable so that they may be subjected to the angular displacement even by the slight depressing force of the toner.
  • the cleaning device 9 generally includes a magnetic brush cleaning means 122 having a permanent maanet member 121 fixedly provided within a hollow sleeve 120 of non-magnetizable material which is driven for rotation, a restricting member 123 for restricting the bristle length of the magnetic brush to be formed on the peripheral surface of the sleeve 120, a toner receptacle 124 for receiving therein the toner removed by the magnetic brush cleaning means 122, a feed-in means 125 for forcibly feeding the remaining toner restricted by the restricting member 123 into the toner receptacle 124, a hair brush roller 126 provided at the upstream side of the magnetic brush cleaning means 122 along the rotational direction 5 of the photoreceptor drum 4, and a charge eraser lamp 127 provided within the hair brush roller 126.
  • the hair brush roller 126 is composed of a cylindrical member 128 of light transmitting material, for example, glass or the like, and a large number of brush bristles or brush hairs 129 of flexible material, for example, acrylic resin filled on the outer peripheral surface of said cylindrical member 128, and is disposed in a parallel relation with respect to the axis of the photoreceptor drum 4. As shown in Fig.
  • the brush bristles 129 are filled on the outer peripheral surface of the cylindrical member 128 in a spiral configuration at a predetermined width d, with light transmitting portions 131 being formed between the neighboring bristle-filled portionsl30 as shown.
  • the length of the brush bristles 129 is so determined as to contact the peripheral surface of the photoreceptor drum 4 by a length 6 from the free end of said bristles (Fig. 8).
  • the length 6 should suitably be in the region from 1 to 5 mm.
  • the opposite ends of the cylindrical member 128 are journalled by side plates 133 of a frame 132 of the cleaning device 9 through corresponding plain bearings 134.
  • a charge eraser lamp 127 having a length longer than said cylindrical member 128 is coaxially extended, while the opposite ends of the charge eraser lamp 127 are secured by supporting means (not shown).
  • the cylindrical member 128 is driven for rotation in the direction of the arrow 135 in Fig. 8.
  • the amount of light projection by the charge eraser lamp 127 onto the photoreceptor 3 may be properly determined by suitably setting the intervals of the light transmitting portions 131, number of revolutions of the hair brush roller 126, and contact length 6 of the hair brush roller 126 with respect to the photoreceptor 3.
  • the magnetic brush cleaning means 122 is disposed at a position close to the photoreceptor 3 in a relation parallel to the axis of the photoreceptor drum 4.
  • the gear 57 is fixed to the other end of the sleeve 120 which extends through the side plate 133 via a bearing 142.
  • the other end of the permanent magnet member 121 is supported by the sleeve 120 through a bearing 143.
  • the permanent magnet member 121 is magnetized by a magnetic poles equally spaced in the circumferential direction, with the neighboring magnetic poles directed to have alternately opposite polar orientation.
  • the power is transmitted to the gear 57, whereby the sleeve 120 is rotated in the direction indicated by the arrow 144.
  • the magnetic brush having the predetermined bristle length is formed by the restricting member 123 so as to be in contact with the photoreceptor drum 4.
  • the mono-component magnetizable toner remaining on the photoreceptor 3 is attracted onto the sleeve 120 through the magnetic attracting force of the permanent magnet member 121, and thus, removed from the surface of the photoreceptor 3.
  • the toner remaining on the photoreceptor 3 is displaced over the peripheral surface of the photoreceptor 3 through action of the hair brush roller 126, while the entire peripheral surface of the . photoreceptor 3 has been erased for charge, since the light from the charge eraser lamp 127 is projected thereonto through the light transmitting portions 131. Therefore, in the magnetic brush cleaning means 122, the toner on the photoreceptor 3 is readily attracted onto the sleeve 120, with a further improvement of the cleaning efficiency by the magnetic brush cleaning means 122.
  • the restricting member 123 is fixed to the frame 132 in a position close to the peripheral surface of the sleeve 120.
  • the restricting member 123 the bristle length of the magnetic brush on the sleeve 120 is restricted, while the feed-in means 125 is provided for feeding the surplus toner thus restricted into the toner receptacle 124.
  • the toner receptacle 124 open at its upper portion is provided, and between the magnetic brush cleaning means 122 and the toner receptacle 124, there is formed a passage 145 for feeding-in the toner.
  • the toner feed-in means 125 is provided at the upstream side with respect to the restricting member 123 along the rotational direction 144 of the sleeve 120 at an opening 145a of the passage 145 at the side of the cleaning means 122.
  • the rotational direction 149 of the rotary shaft 58 is selected to be opposite to that of the sleeve 120, whereby the surplus mono-component magnetizable toner restricted by the restricting member 123 is transported by the toner transport member 148 so as to be positively brought into the passage 145.
  • the mono-component magnetizable toner thus fed into the passage 145 falls in the passage 145 by its own weiqht and fed into the toner receptacle 124.
  • the toner receptacle 124 is placed on a microswitch 150 as a switching means, which is set to be rendered conductive when the mono-component toner to be accommodated in the toner receptacle 124 reaches a predetermined weight.
  • the microswitch 150 as described above is connected to a toner collection indicating means such as a pilot lamp or the like, and is arranged to illuminate the pilot lamp when the weight of the mono-component magnetizable toner within the toner receptacle 124 has reached a predetermined level. Accordingly, it is readily detected that the toner receptacle 124 has been filled with the mono-component magnetizable toner.
  • FIG. 12 showing a cross sectional view of a developing apparatus according to another embodiment of the present invention, by which the developing apparatus 7 of the embodiment of Figs. 1 through 11 may be replaced.
  • the permanent magnet member 77 is magnetized by a pair of magnetic poles (S poles in this embodiment) having the same polarity in a position corresponding to the position of sliding contact of the blade member 76 with the developing sleeve 71.
  • S poles in this embodiment the magnetic poles are disposed at intervals of 2 to 6 mm on the circumferential surface of the parmanent magnet member 77.
  • the magnet member 77 is magnetized by the magnetic pole neighboring said two magnetic poles (S poles in this embodiment) and having polarity opposite thereto (N pole in this embodiment). Since other constructions of the developing device of Fig. 12 are generally
  • the permanent magnet member 77 is magnetized by a pair of magnetic poles having the same polarity (N poles in this embodiment) in the range from the developing position 86 to the blade member 76 along the rotational direction 85 of the developing sleeve 71.
  • These magnetic poles are arranged, for example, at intervals of 2 to 6 mm on the circumferential surface of the permanent magnet member 77. Since other constructions are generally similar to those of the arrangement of Fig. 3, detail description thereof is also omitted here for brevity.
  • the mono-component magnetizable toner of the magnetic brush formed on the surface of the developing sleeve 71 not contributing to the developing, and rotated together with the developing sleeve 71 from the developing position 86 is temporarily displaced when it passes the position at which said magnetic poles of the same polarity are disposed close to each other.
  • the above displacement takes place because, in the region between the developing position 86 and the position at which said magnetic poles of the same polarity are disposed, the regular variation of the chain structure of the magnetic brush owing to the alternate arrangement of the N poles and S poles is shifted towards irregular variation.
  • the mono-component magnetizable toner whose magnetizing function is thus weakened is transported up to the position of the blade member 76, the toner may be easily peeled off or scraped off from the peripheral surface of the developing sleeve 71. Similar to those of the arrangement of Fig. 3, detailed description thereof is omitted here for brevity.
  • the attracting force for attracting the mono-component magnetizable toner onto the developing sleeve 71 at the sliding contact position of the blade member 76 is weakened.
  • the magnetic lines of force from the magnetic poles of the same polarity are directed in the radial direction of the developing sleeve 71, the mono-component magnetizable toner is subjected to the magnetic attracting force in the tangential direction of the developing sleeve 71.
  • the mono-component magnetizable toner on the developing sleeve 71 is separated from the surface of the developing sleeve 71 at a position before the sliding contact position of the blade member 76, and jumps over the sliding contact position to be transferred to the blade member 76, and thus, reaches the passing holes 106. Accordingly, in the above arrangement, it is not necessary to cause the blade member 76 to strongly contact the sleeve 71, and therefore, the undesirable blocking of the toner by the blade member 76 can be prevented.
  • FIG. 13 there is shown, on an enlarged scale, a cross section of a developing apparatus according to a further embodiment of the invention, in which like parts corresponding to those in Fig. 3 are designated by like reference numerals.
  • the position at which the pair of magnetic poles of the same polarity close to each other are to be magnetized is not limited to be one position as described in the above arrangement of F ig. 13, but may be further modified to be provided at a plurality of spots in the range from the developing position 86 to the blade member 76 along the rotational direction 85.
  • a modified hair brush roller 151 according to the present invention, by which the hair brush roller 126 in the embodiment of Figs. 1 through 11 may be replaced.
  • the hair brush roller may be formed by filling the hair brush 129 on the peripheral surface of the cylindrical member 128 in a lattice-like pattern.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
  • Cleaning In Electrography (AREA)
EP19810300404 1980-01-31 1981-01-30 Dispositif de nettoyage pour appareil de tirage électrostatique Expired EP0033647B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE8383109210T DE3176117D1 (en) 1980-01-31 1981-01-30 Developing device for an electrostatic copying apparatus

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
JP1980012037U JPS6333225Y2 (fr) 1980-01-31 1980-01-31
JP1980012034U JPS6328435Y2 (fr) 1980-01-31 1980-01-31
JP11810/80 1980-01-31
JP1980012036U JPS6328436Y2 (fr) 1980-01-31 1980-01-31
JP12034/80U 1980-01-31
JP12036/80U 1980-01-31
JP1181180A JPS56107274A (en) 1980-01-31 1980-01-31 Developing device of electrostatic copier
JP1203580U JPS56113346U (fr) 1980-01-31 1980-01-31
JP12035/80U 1980-01-31
JP11811/80 1980-01-31
JP1181080A JPS56107280A (en) 1980-01-31 1980-01-31 Cleaning device of transfer type electrostatic copier
JP12037/80U 1980-01-31

Related Child Applications (2)

Application Number Title Priority Date Filing Date
EP19830109210 Division EP0103310B1 (fr) 1980-01-31 1981-01-30 Dispositif de développement pour copieur électrostatique
EP19830109210 Division-Into EP0103310B1 (fr) 1980-01-31 1981-01-30 Dispositif de développement pour copieur électrostatique

Publications (3)

Publication Number Publication Date
EP0033647A2 true EP0033647A2 (fr) 1981-08-12
EP0033647A3 EP0033647A3 (en) 1981-12-30
EP0033647B1 EP0033647B1 (fr) 1985-08-21

Family

ID=27548357

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19810300404 Expired EP0033647B1 (fr) 1980-01-31 1981-01-30 Dispositif de nettoyage pour appareil de tirage électrostatique

Country Status (2)

Country Link
EP (1) EP0033647B1 (fr)
DE (1) DE3171869D1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0230791A1 (fr) * 1985-12-27 1987-08-05 Sharp Kabushiki Kaisha Détecteur pour récipient à toner de déchets plein

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3615813A (en) * 1969-05-19 1971-10-26 Ibm Electrophotographic layer cleaning process and apparatus
JPS5213343A (en) * 1975-07-22 1977-02-01 Ricoh Co Ltd Toner cleaning device for the electrophotographic copying machine
JPS5446044A (en) * 1977-09-19 1979-04-11 Mita Industrial Co Ltd Cleaning of residual toner in transfer type electrostatic copying machine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0230791A1 (fr) * 1985-12-27 1987-08-05 Sharp Kabushiki Kaisha Détecteur pour récipient à toner de déchets plein
US4750015A (en) * 1985-12-27 1988-06-07 Sharp Kabushiki Kaisha Waste toner container detector

Also Published As

Publication number Publication date
EP0033647A3 (en) 1981-12-30
EP0033647B1 (fr) 1985-08-21
DE3171869D1 (en) 1985-09-26

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