DE2032369A1 - Recovery device for toner material - Google Patents

Description

Patent attorneys Dipl.-Ing. E Weickmann, 2032369

D1PL.-ING. H.WEICKMANN, DIPL.-PHYS. DR. E. FlNCKE Dipl.-Ing. F. A. WEICKMANN, D1PL.-CHEM. B. Huber S MUNICH 16, DEN

BOX 160120

MDHISTRASSE 22, CALL NUMBER 483921/22 ZSROZ COSPOBATION, So cheat he, H.Y. 14603, V.St.A. Recovery device for toner material

The invention relates to a recovery device for Remaining toner material on an electrophotographic image plate after the image transfer

Such a device is intended, in particular, for removal in automatic electrophotographic production machines and collecting residual toner from a movable photoconductive image surface after image transfer, and allow the collected toner material to be returned to the developing device so that it can be used repeatedly in the developing process

In the electrophotographic process, as it was for the first time in the US Pat. No. 2,297,691 discloses an electrophotographic imaging plate formed from a conductive substrate and a photoconductive insulating material applied to it, is uniformly electrostatically charged and exposed to a photo of a reproducing original. The photoconductive material becomes conductive through the incidence of light, whereas the electrostatic charge is selective »» Is conducted and an electrostatic »latent image is created ·· stands · This is done duroh application of a pigmented Xunethar powder made visible saw developed, voau ver

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Such pigmented synthetic resins have been specially developed · In the electrophotographic process, the pigmented synthetic resin or the toner is electrostatically removed from the latent Image on the photoconductive layer in one of the respective Charge density corresponding amount attracted · Areas of low charge concentration are only faintly tinted while Areas of greater charge concentration are toned accordingly more densely · The fully developed image is then of the Image plate surface on another image carrier, for example on a sheet of paper, transferred and on this fixed to create a permanent image

Most of the toner is used in image transfer the photoconductive image area transferred to the image carrier · However, it was found that the toner particles The forces binding the photoconductive image area are sometimes stronger than the image transfer forces, which is why a A certain amount of toner remains on the photoconductive image surface after the image transfer.If it is not removed from the image plate, this residual toner can have a harmful effect on subsequently generated images

Sine disk cleaning is automatically working electrophotographic reproduction machines in which the Image plate is used continuously, with various devices, for example with fiber brushes, cleaning tapes, wiper blades or the like. The toner removed in this way is achieved is usually collected and stored in the machine and then removed periodically. Most in automatic electrophotographic reproduction »* cleaning methods used for a photoconductive · image surface cause dirt, are uneconomical and costly · that of the plate surface removed fine toner is extremely difficult to handle and

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often migrates from the cleaning device to other areas of the machine so that machine parts become dirty · Se It has also been found that the residual toner removed from the electrophotographic imaging plate constitutes an extremely high percentage of the total toner used represents. Since this toner has always been removed, it increased the operating costs significantly

The object of the invention consists in the electrophotographic process in particular for automatically operating To improve reproduction machines in such a way that a more economical utilization of the toner is possible Any remaining toner on an image plate after the image transfer should return to the development cycle for this purpose to be forwarded

A device of the type mentioned is characterized for This object is achieved according to the invention by means of a device for removing the residual toner material from the image plate, by means of a device for collecting what has been removed Toner material in a sump and through a pipe connecting the sump to the image developing device, which is a conveyor chain with a slightly smaller outer diameter than the inner diameter of the pipe and transports the toner from the collecting container to the developing device

An exemplary embodiment of the invention is described below with reference to the figures.

Fig.l is a schematic representation of an electrophotographic reproduction machine equipped with the device according to the invention,

Pig. 2 a side view of the drum cleaning device, the conveyor chain and the conveyor drives and the developing device for the one shown in Fig.1

009864/1930

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Machine,

3 shows a partial view of the return winch device shown in Pig.

Pig 4 the arrangement of the conveyor chain on a toner input device,

Fig. 5 shows another embodiment of a cleaning device. treatment with an electrically pre-tensioned cleaning brush and

6 shows an enlarged perspective illustration of the conveyor chain and the pipeline with an arrangement for evenly distributing the toner material in the Development housing ©

The automatically operating electrophotographic reproduction machine contains an electrophotographic image plate, which consists of a drum-shaped and electrically conductive layer carrier 10 and a photoconductive layer applied to it. "The drum is rotatably mounted on a shaft 11 in the machine frame."S> i® is divided into the Pfeinrichtung shown in Fig. 1 in such a way ₉ äal your® obsr surface before moving past a myriad of electro-photographic driving stations one after the other

These process stations are based on their function briefly described below

At an Iiadestation A a uniform elek-feroetati " see charge on the photoconductive Sohiöht ier ®l @ ktrofotow graphic drum applied "

At an exposure station B, a light image of an original to be reproduced is projected onto the surface of the surface, so that the outer surface in the irradiated areas is derived and produced in a latent electrostatic image.

Q09884 / 193Ö

At a development station C, an electrophotographic developer material with toner particles, which is one of the charge «lektro« polarized in the opposite direction to the drum surface · have static charge over the moving drum surface cascaded so that the toner particles adhere to the electrostatic latent image and in the same way as the original make speaking configuration visible »

At an image transfer station D, the electrophotographic toner image is electrostatically removed from the drum surface transferred to another image carrier and

at a drum cleaning and toner collecting station 1 the drum surface was treated with corona discharge first and then with a squeegee blade to remove any residual Wiped off toner particles, after which the wiped off toner is collected for reuse ·! Furthermore, the drum «« surface illuminated for a practically complete display * elimination of any residual electrostatic charges «

The loading station is preferably at the lower part of the drum placed at point A (? ig »1) · For electrostatic A corona discharge device 13 is provided for charge which contains an arrangement of one or more corona discharge electrodes, which run across the drum surface and are fed with a high voltage source The corona discharge electrodes are arranged in a shield which limits or concentrates the discharge to a specific area.

The dl · charging station is followed by dl · Beliohtuageetation B ₉ at which • In continuous ·· Idoht image of a stationary original · is projected onto the · Troaatlourfläoht. The optical scanning and projection device contains a stationary and transparent support plate 14 on which the original to be reproduced is placed? * Rn «r let a lamp LMP-1

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2032389-

- ο * ·

join, the ο the original uniformly illuminated, the reflected on the original is a pleated optischea system with a Objektepiegel 16 »a bewegließen optics 17 and a Bildepiegel 18 to the drum surface sur fa ~ ohenelementweise projected, so that & in from surfaces © lementen composite continuous light image on the! drum · · surface · The optics are arranged under the platen in such a way that they can be moved parallel to its plane "so that the original is scanned in time with the movement of the photosensitive drum surface".

A © lighting device is located near the lighting station

19 arranged, which the drum surface in the areas illuminated or «discharged between individual images, so this one initially loaded but not provided with an image Areas cannot be developed when the drum- surface is moved through the development station *

At development station 0 is a development device

20 arranged with a development housing 28, in the lower Rope a supply of a two-component ^ development- · lere is provided o A bucket conveyor 27 with a drive device is coupled, is used to! Transport the developer from the supply sber egg oh in the upper part of the egg " wioklungsgehäuses, from where it reaches a funnel 29 · He moves in contact with # ®r moving upwards. photoconductive Troamel surface · abwirts® Sie Sonteilohui are in the picture area ler Irommelofeerfläöha " depending on the Iß # «jigak®na®ii.teat ± öm deposited and generate a # ntwi®ta§lt ·. «elektrof © togr & fi« · ■ ohte toner image · The aioht aur Batwleklttng Terwendtt · Emtwiok « Fabric becomes the tone of the maidservant d ·· Sn t winding β housed · sartLekiifUhrt · » tografieohtr Toner is d «f latwiekltritoffmieoktt ^ g Im dta Tonervtrlirauoh tnt «prt« liea <ttii itnge old «iatr

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device 21 and with the invention and still to associated recovery device included

Copy sheets are sequentially transferred from an upper sheet tray 35 or a lower sheet by the image transfer station D compartment 34 with a dismantling and conveying device 22 * The correctly aligned sheets are brought into contact with the moving drum surface » and the developed toner image is electrostatically applied to the drum surface with a transfer corotron 24 Transfer copy sheet · The electrostatic field generated by the corona discharge device binds the copy sheet electrostatic on the drum surface, causing it moves synchronously with it as long as it is in contact with it *

Immediately next to the transfer station, a mechanical lifting finger 25 is arranged pivotably on the drum surface. It can be brought into contact with the moving drum surface before a leading edge of the sheet arrives electrostatic binding force that holds the copy sheet on the drum surface Due to the arrangement and the shape of the lifting finger, the leading edge of the respective copy sheet is guided upwards to a stationary vacuum transport 26 The trailing edge of the copy sheet, which is still electrostatically bound to the drum surface, moves further and pushes the copy sheet along the lower surface of the vacuum transport to the fuser 30

The copy sheet provided with an image moves along the vacuum transport into the gap between the upper fixing roller 31 and the lower fixing roller 32 dtr the fixing device

009884/1930

tion 30. Both roles exert a sruok and thus a driving force on the copy sheet aue “A radiant heater
33 is arranged parallel to the lower egg roll and transfers thermal energy to the cover »The should is covered with a material that absorbs the thermal energy transferred to it on its outer surface Hollen existing copy "sheet transferred, which caused a picture fixation as a result
a combination of τοη heat and pressure induction »is produced;

After this. Leaving & @ r fisiarvorrlQlatmag the © finished copy is over a curved one
and transport roller anoraa
Guided tours can be done in this way

in the upper sheet faeh 39 © ä®r in © in Ausgafesfaoli 37
The EeproduktioiiBiaaBGlxin © Ieebb.

«Read paper transport system ©ia.ii@itig with B ± lä © ra · ψ®Ί
pielblätter in ias ober © Blüttfaoh 35 traaspertisrto 'Biss © leaves are iaan nootoals an & q ^ © l © k "ferof © tografiis © la © a Bildtiliertragiiagsstatioa vörbeigofüh ^ ts so cl
on the side with a picture versnheaoQ topisblGtt © ntstugt ;, öam in the described manner © auis ü®t lasehiae ®, usg @ g © lb © a w ± ¥ & o

After all , it’s not enough

station B forge see ₉ en üqt Qia®

dete

the

the di © Blldlifeertra

is collected rough! in. »© sucht St ssa

wioklungsvorriohtiuag

According to a "vorziagtea

a reoliteokföriiiges fl © 3si '© l @ © sheet

High toner e from ies ³

The sheet is fixed to a sheet holder 51, which forms a wall of a cleaning and collection housing 40 (FIG _e 1). The sheet normally rests in pressure contact across the entire width of the photoconductive drum surface. The edge formed between the narrow side 47 and the underside 48 of the sheet is located slightly below the horizontal bisector of the drum Toner material lifts off, as it is when a chip is lifted from a workpiece with the sonic tool of a lathe of the Pail.It has been shown that the forces exerted by the blade are similar to those of a sonic steel o The blade is therefore stored like a son's steel and has a light weight Sawing with a back-up angle · The back-up angle between the underside of the blade 48 and a tangent plane touching the drum surface at the line of contact can be changed for different blade types in order to avoid vibration or other undesirable effects of incorrect blade arrangement Edge 47 of the sheet should be beveled near the back so that a sharper tail edge is on the drum surface and thus a better cleaning effect is achieved.

Any suitable non-metallic and flexible material can for a cleaning sheet of the device according to the invention · Typical non-metallic «flexible materials are used are! Polysiloxane rubber, polyurethane rubber, polytetra · » Fluoräthylenhara, Polytrifluorohloräthylenharz, Styrol-Buta *. Diene chew, nitri! rubber, nitrosilioon chew, more flexible Polyurethane foam, polyethylene resin and mieohungen, Additions and copolymers of this substance ·· Das Äbetreiohblatt should bo weloh "tin that" an image disk wear in the " special at Selenbildfläohtn is kept minimal · Before * 8Ug »w« i ·· »oll aa · Leaf material has a Shore hardness of less

009884/1930

than 75 durometers. Tests have shown that leaf thickness " ken can be used within a relatively wide range without a noticeable change in the cleaning properties to cause «»

By arranging the scraper blade a little below a horizontal bisecting plane of the drum and by slightly sloping the blade edge, more easily removed toner will fall on the back of the sheet, which is waved from the surface of the sheet, as can be seen from Figures 2 and 3 The toner runs in a longitudinal direction over the drum surface in a channel 53. A screw conveyor 55 is rotatably mounted on a shaft 54 in the end plate 56 and the cover plate 62. It is arranged parallel to the scraper blade and conveys the drum surface ® detached toner particles to the toner collecting housing® 61 _e

The channel 53 has a cover plate 56 at one end closed, while its other end in the collecting housing 61 is attached «It is connected to the collection area 57 provided in this housing«, the end of the shaft 54 protrudes through the Abeohlußplatt © 56 hinduroh anä is there with a drive tooth rafi 85 This is the main drive of the reproduction machine geireht uelä teevj®gt the for- » those in such a way that the snail d®a toner out of the area « ter the Abetreiohblatt in 0eitl ± 0h © r Hiohtimg ia Area 57 promoted®

Am drive gear 63 for © inen Shaft 82 in the collecting housing 61

Main drive system derlas @! IiaQ WbQT äi® IqIIq 54

Son tokenfOrderers driven 54 attached® Zataraö 84 ( 83 »dae in a tooth 81 bike 63 on a joint

- π -

is an endless chain conveyor 64 · guided · the gear acts on this conveyor and guides its chain parts, which are designed as balls, in the direction of the arrow «

The remaining toner, which is in the collection area 57 of the collection and drive housing 61 is collected, becomes the development housing with which the pipe system 66, 67 is guided Conveyor fed. This includes an adapter element 70 on the Development housing 28 and a toner distribution and Rüok « guide soles 71 · The different types of this conveyor system forming parts are adapted to one another in such a way that a continuous and closed conveyor circuit with a uniform inner diameter from the collecting area 57 over the entire Width of the development housing and back to the collector * is richly educated. As can be seen from Figs. 2 and 3, the endless conveyor chain guided over the drive gear 63 and moves in this conveyor circle from the collection area through the Development housing and back · The inside diameter of the Drilling lines is slightly larger than the diameter of the production balls so that they can move freely in the lines but carry the particulate toner with them

The endless conveyor chain moves through the collecting area 57 the collected toner material downwards. The balls press the toner material mechanically downwards into the feed tube 66. Absohlußplatte 65 of the collecting housing imprinted «The delivery pipes can be done with adjusting screws or similar fastening elements «! additionally be attached. The other end of the feed tube 66 is similarly to the connector 70 of the development housing. The feed pipe 66 and the return pipe 67 are preferably made made of a flexible plastic, which in the way shown in Pig.

009884/1930

th way from the cleaning and collecting device 40 duroh the machine is led to the developing device 20, whereby stationary machine parts are avoided _e This arrangement enables a versatile use of the device according to the invention. It can be arranged at any active remote point on the machine and can be connected to the developing device «,

A roller input device 77 supplies fresh toner entered into the lower part of an input trioher 75 This is arranged between rails 73 and 74 (Pig «» 4) and runs over one provided in the development housing Input opening. The hopper can feed the toner directly into the developing housing at a predetermined speed, when the input roller 77 is rotated »

The connecting element 70 is secured with its Yoreprüngen 72 to the rails 73 and 74 for example with screws, "The toner leading through the supply pipe 66 into the development housing chain conveyor is geführtj via a bend of Ca ₀ 90 ° when it passes through DA® Anaohlußelement 70 so that it parallel to rail 73 exits _β the loop 71 is also made of a relatively rigid plastic and is mounted such on the connecting element 70 'that they ssu parallel under the Eingabetriohter runs the rails this. The chain conveyor entering into the setting mode of Entwioklungsgehäuses is first major © h a tubular member made of the step-like with a number of cutouts 90 is provided shaped U-in its cross-section ₀ As shown in! Ig.6 apparent, the level of each recess with increasing length this tubular part is placed lower and lower in the development housing. When the chain conveyor moves through this area, the toner is discharged through these cutouts in such a way that it is evenly distributed over the width of the developing housing. The chain conveyor is going around

009884/1930

the loop is led around and experiences element 70 in the connection again a change of direction of 90 °, after which he duroh that Return pipe 67 back to the collecting and drive housing 61 got back

Between the open channel 53 and the moving (drum surface Seals are provided to prevent residual toner from escaping from the cleaning and collecting device «Since this creates a closed system, can little or no free! Doner in the same Masohinenbereiohe reach. The inventive cleaning "and Sam" Meling device not only works extremely cleanly, but also protects the neighboring machine parts against contamination by loose or free toner parts »The entire Heini ·· supply and collecting device 40 (Pig.i) is on swivel arms 58 arranged, which sit on a support rod 59 mounted on the machine frame · For easier removal from the machine can the entire device 40 on the rod 59 of the Drum surface can be swiveled down · The open Channel 53 moves downwards and forms a container for loose toner particles, which at this point are in of the device. Will this return to the inig.2 If the operating position shown is moved back, a resiliently pretensioned pawl 86 with a pin 87 assigned to it is moved back locked and with a locking mechanism 88 in this Position held. In the operating position of the cleaning and Collecting device exercises the cleaning edge of the flexible and a self-adjusting scraper blade Pressure contact on the drum surface.

In Pig 5 there is a second embodiment of the invention «En device shown, the bit of an electric gate ·· tense burst instead of the scraper blade aur removal tion of residual toner particles from the photoconductive * !! Security area is working. The device consists of a housing

009884/1930

91 »which is attached to the machine frame · There is a fiber in it brush 92 arranged, which the moving drum surface touches «While the cleaning fibers on the top of the drum» surface is passed, a voltage with one polarity opposite to that of the charge of the toner particles on the conductive cylinder of the brush, so that electric field lines in the radial direction from the cleaning fibers go out and the toner particles are transferred to the fibers by attraction, a direct voltage the voltage source 101 via a coordinator line 104 connected to the conductive brush cylinder®

The Reinigungsfaaern advantageously consist of a non-conductive material, i.e. a short circuit @ r accompanying direct voltage prevented and through! SuQhtigteeit hike s is not affected ο! Typical suitable Stoff® are Aerylfasern, velvet, Orion, Polypropylenstoffeg Hylon, rayon _f Acetate, mohair, & las ₉ Dynel * Daoron _p cotton mm. Over other® natural and / or synthetic! Fibrous material as well as their loops * furthermore, the burs teuf as am can consist of ® ± with fabric, which is tied with a tearable material .S! Qhe absorption of the material causing the particles is coated ± st _s which means that the cleaning qualities are ier Burst® w @ it @ r T © rbesa®rt © Typical substances with aerelike a friction-elicfecting properties for well-known toners are ' in aen TO ^ fateatsohriftea 2 618 551 and 2 618 552 "besoliriebeao B © m Äetaana is clear ₉ that by Yeribesseriiing
nigungbrush dmroh such substances
fabrics in dar raifeuB
time reduction ier

times «on the

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The pretensioned roller 102 is arranged in the area of movement of the cleaning fibers and with a voltage source 100 The role is connected via a commutator line 103 charged to a voltage with a polarity opposite to that of the charge of the toner particles, namely with of such a strength that the particles from the fibers of the Cleaning brush can be transferred to the roller. The role 102 is rotatably mounted in the housing opposite to the direction of rotation of the brush, an angular velocity being used which is opposite that of the cleaning brush is different, so that a relative movement between both parts is maintained permanently · In order to allow a clean surface to act on the brush fibers at all times and to facilitate the recovery of the toner particles so that they can be reused in development, a pad device is provided on the roller 102. This consists of a sheet 95 with holding elements 94 and 96 is firmly mounted. The retaining elements are with the housing 91 connected by one or more adjustable bolts 93, each of which in an insulating mounting block 98 With a nut 99, the retaining elements are pressed against a compression spring 97, which is attached to the insulating fastening block 98 is arranged. Contact pressure between the sheet and roller 102 can be achieved by turning nut 99 on Bolts can be changed or adjusted

The toner particles are removed from the surface of the roller 102 removed, they fall into the channel 53 and are conveyed in the lateral direction into the collecting area 57 Collected toner particles are then fed to the development housing in the manner described above with the chain conveyor, where they are re-entered into the development cycle »

The invention has been described above on the basis of exemplary embodiments

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2 υ J 2 3 6

len described, but is not limited to them. All Embodiments possible within the scope of the following claims are encompassed by the basic idea of the invention

ORIGINAL INSPECTED 0 ü 9 8 P 4/1 8 3 U '. ^ ~~

Claims (1)

Pat ent anaprüohθ le recovery device for on an electrophotographic Image disk still available after image transfer remaining toner material, characterized by a depositing device (47) for the remaining toner material from the image plate (10), through a device (55 »57) for collecting the detached toner material in one Collecting tank (57) »and through a pipe (67) connecting the collecting tank (57) to the image developing device (20), the" a conveyor chain (64) * with a slightly smaller outer Durohinesser than the inner diameter the pipe (67) and the toner from the collecting container (57) transported to the developing device (20). · 2 »Device according to claim 1, characterized in that the conveyor chain (64) is designed as an endless chain, and moved in a closed loop away from the collecting container (57) and the developing device (20) will" 3 * device naoh claim 2, characterized in that the pipeline (67) from the collecting container (57) through the Enb '/ iioklungvorrichbung (20) and aum collecting container {■)!) Is hurüakgo, and that the conveyor chain (64) niLb ilri'i.-ii üri.triobfjül8iu *) nt (63) coupled to movement düroh dio liohj>> ■■ '^ i-tu.ng (67) coupled to Ulöo ^ m Wag iot,> i- it'i vnoh dtidiii '<m (<> i): i L »i iiaima t j U la a) iiil ύ'ϊ 'it} υ L ■: i -5: ϋίΙΐί ib - ^ z ih afc ^ .1 in the BATH ₁₈ 2ÜJ2369 5 »Device naoh one of claims 1 to 41 daduroh characterized in that the pipeline (71) in the area of Development device (20) an input device (90) for inputting the recovered residual toner material assigned to the developing device (20) lsi; Device according to claim 5, characterized in that that the input device (90) consists of openings provided in the pipeline (71) which through their A uniform toner input over the length of the pipe (71) in the developing device (20) guarantee". 7 · Device according to one of claims 1 to 6, characterized characterized in that the detachment device (47) is a flexible ** les cleaning sheet is movable relative to the image plate (10) and this is arranged in contact in such a way that it slides between the remaining toner material and the image plate surface « O ₀ device according to claim 7, characterized in that the collecting device (55) for detached toner material is a screw conveyor (55) which is arranged transversely to the image plate surface and which picks up the detached toner material near the cleaning sheet (47) and delivers it at once trWtoa element (85) caused rotation in the collecting container (fi /) ba for dar fco naoh oinem dor claims 1 to 6, thereby ga »j daö dia AbloaevörrltihlRim * öina ft-'j Röirtigun-gijbürsIjo (i) 2) with nX v.liö i'alt one polarity Bniiuii ^ iia iun-i duct ve® " üllßhen i) η Ί Uli7,: / T l-Pi: 10. Device according to one of the preceding claims, characterized by the arrangement on a drum-shaped trained and rotatably mounted electrophotographic image plate (10). 009684/1930