CA1048591A - Photocopy machine with photoconductor belt and cartridge for photocopying - Google Patents

Abstract

PHOTOCOPY MACHINE WITH
PHOTOCONDUCTOR BELT AND CARTRIDGE FOR PHOTOCOPYING
Abstract An apparatus for making photocopies is disclosed with a photoconductor belt adapted to move around a roller assembly with a cartridge which contains belt replacement segments. The roller assembly meshes with the cartridge to enable rapid continuous movement of the photoconductor which passes a flat region where the belt receives a flash exposure of an object. A mechanism and method for continually replacing the photoconductor belt with in-cremental fresh segments from the cartridge is described to pro-vide gradual replacement thereof with a long effective usable lifetime for the photoconductor belt and cartridge assembly.

Description

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Field o~ the InYention This invention xelates to a photocopy machine. More specific~lly~ this invention relates to a photocopy machine using a photoconductor belt.

sackgrouhd of the Invention The xerographic photocopying process has been exten-siyely described and is well understood. Typically, a photo-conductiye material is mounted on a drum or on an endless belt to hold a latent electrostatic charge image prior to develop ~ent and transfer to a plain paper copy.

In one type of photocopy machine a photoconductor drum is employed. While the drum is rotated it is exposed to a line image of an object by the relative movement between .. .
a, sl~t and an illuminated object. In another type of photocopy ' m~chine the drum is replaced with a photoconductor belt which may be endless for continuous motion along a belt path. The ;
~elt path is defined by a plurality of roller elements which are spaced to provide a belt path section where the belt is ,f,lat while being exposed to a planar image of the object ~nstead of through a moving line image.

~ The flat photoconductor belt section may be flash ;; exposed. ~When the light intensity oE the flash is sufficiently high, the exposure time may be so short that blurring of the la~tent image on a continuously moving photoconductor belt is reyented, The short flash exposure of the entire object 26 enables a high speed photocopying operat~on.
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1C~48591 Various materials haye been proposed fo~ photo~
çonductors in photocop~ machines, One well known material is made of a selenium material which is capable o~ producing ~ substantial number of copies before replacement. Another material m~y be o~ the organ~c type such as described in the U, S. patent to Shattuck et al 3,484,237. However, an orgànic photoconductor material has a limlted useful li~e and thus ~e~uires replacement ~n a manner such as, for example, taught ~nd shown in the U. S. patent to Berlier et al 3,588,242.

In the Berlier patent a copy drum is described utilizing an organic photoconductor stored as a flexible strip on a supply reel located within the interior of the drum.
The photoconductor is fed around the external periphery of the drum and returned to a take-up reel located inside the drum. The entire photoconductor strip used on the drum is periodically automatically replaced with a fresh unused photoconductor on the supply reel after a certain preselected number of copies have been made.

Another approach for replacing a photoconductor belt is described in the U. S. patent to Swanke 3,619,050.
In this patent a photoconductor web is stored in a cartridge located near a photoconductor belt path. A photoconductor segment is ~ormed into an endless belt by use of a connecting tow ba~ and wrapped axound appropriate roller elements which define the photoconductor belt path necessary for exposure, txans~er and development of the copy. A replacement of the u~ed ~eb is c~rried out by tak~ng selected segments ~rom cb~ 3 the nearby available c~rtrldge su~ply ~nd feeding thls around the rollers and then reconnecting the ends at the two bars to fo~m an endless belt. A complex mechanlsm for replace- ;
~ent of the photoconductor is described involving substantial ~anu~l contxol.

In the German patent publication 2,309,296, publish-ed on September 6, 1973, based upon an application date of ~ebruary 24, 1973, a photoconductor is formed into an endless loop. The loop forms a remo~able cassette having a supply 10 , ,roll and take-up roll. The loop is passed around rollers ~ ' ~nd a copy platform around which an exposure area and a print-~n~ stage are closely grouped. The cassette moves back and ~orth ~long a straight path during the copying process. ~ , ' .: ' ' The desirability of using a flash exposure of a flat photoconductor segment may be appreciated. The moving ~ ~ ,sl,i:t mechanism to expose a drum-type photocopier with a line segment is deleted and a relatively convenient and economical optical exposure system can be used. This advantage of the ~elt photocopier may be appreciated from the large number of '~
b,elt photocopiers described in the art such as in the U. S. ' patents to Gardner et al 3,521,950, Hewes et al, 3,661,452 and ~wanke 3,619,050.
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Although the photoconductor drum structure disclosed ~n the Berlier patent effectively provides a long life by yirtue of the storage of a replacement section within the drum, ~, .

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1C~48591 the Berlier appaxatus still operates with ~ line se~ment exposu~e by ~irtue of its drum ~ounting and does not lend itSelf to the photoconductor belt photocopy machine.

Rnother disadva~t~ge of the Berlier replacement structure inYolves the photoconductor belt replacement opera-~ion. This is carried out after a preselected number of copies haye been made. At such t~me the entire photocopying process i~s, interrupted until the cycle for replacement of the photo-conductor seg~ent extending aro~nd the entire drum is completed.

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The U. S. patent to Begun et al 2,789,776 discloses - a,n apparatus manually positioning successive lengths of a recording medtum on an endless reco~ding track such as on the pexiphery of a rotating drum. Ratchet wheels are employed ,' to pull successiye lengths of the recording medium around the ' , periphery of the drum to expose new lengths for recording ' playback.

,~ Although in a photocopy machine one could employ a longer copying llfe selenium type photoconductor, its cost and manufactur~ng complexities reduce the desirability for such approach; particularly when the selenium photoconductor ~n the belt form has a significantl~ less useful lifetime , than selenium in the drum shape.
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When an organic photoconductor is employed in a ' belt ~orm such'as shown in the appaxatus disclosed in the ,~ , p,a,tent to S~anke, then an undesirable frequent replacement ~peFation must be carried out even though the organic photo-

2~ conductor ~s retained in a nearb~ cartridge.

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16)4~591 Summary o~ the InYention In a photocop~ machine in accordance with the invention, a photoconductor assembly is formed of a photo-c~nductor belt and a cartridge for storing a fresh supply of photoconductor material. The photoconductor belt and ~ rtridge are moved around a belt path formed for a roller assembly. The rollers in the roller assembly are each pro-~' yided with a cartridge receiving recess sized to enable the ,~ ca~tridge to mesh with a roller as the belt and cartridge pass oyer a roller. In this manner the photoconductor belt assembly moVes in a continuous manner and in a uniform direc-t~on around the belt path.

An advantageous feature of this invention involves belt advance mechanism which automatically continually and incrementally replaces the photoconductor belt with fresh seg-~ents. The incremental advance results in a gradual replace-~ent of the photoconductor belt as copies are being made with an advantageously consistent level of copy quality throughout , the useful life of the belt. The incremental replacement further adYantageously distributes physical stresses over the length of the photoconductor belt thus reducing the like-J lihood of physical damage to any one segment.
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, As described with respect to the preferred embodi-'~ ment, the incremental advance of the photoconductor belt ~ ~nyolves ~ Geneva drive whose rotational output is reduced to ,j rotate a belt take-up reel located in the cartridge. ~he Geneva drive may be actuated once during each full copy cycle 28 o~ the photoconductor belt. The xesultant incremental rotation .~ :.

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-~ - 1048591 of the take-up reel produces a corresponding incremental replace-ment of the photoconductor belt, After a large number of copies haye been made, the photoconductor belt segment which was used to make copies h~s ~een replaced with a corresponding fresh seg~ent from the cartridg~.

The cartridge is sized to retain a sufficient supply o~ photoconductor belt material for a satisfactory lifetime o~ nu~ber of copies, Yet the cartridge is sufficiently light ,; . .
, in weight to enable the photoconductor belt to support the ~ ~, cartxidge throughout a copy cycle. The cartridge receiving ,~

, recesses in the rollers are provided with covers whose open-. .j ,` ~ng and closing of the recesses are timed with the respective , ar~val and departure of the cartridge at and from a recess.

, The covers are curved to provide a continuous cylindrical ~-' peripheral roller surface when the cartridge is between the ,rollers, When the cartridge enters a recess the covers are ; opened and the cartridge permitted to make a smooth entry ~nto the recess for a correspond~ngly smooth passage past a roller. In this'manner a continuous photoconductor belt motion is accommodated with a travelling belt-replacing cartridge.

,; It is, therefore, an object of the invention to ,, '~ proyide a photocopy machine of the belt type wi,th an effect-~ yely long cycle life for the photoconductor. It is still :i! ,$urther an ob~ect of the invention to provide a roller assem-~ for use in a belt type photocopy machine to enable a ',~ p~otoconductor belt carrying a replacement segment to be ,' ~ont~nuously moyed. It is still another ob~ect of the inven-29 t~on to provide a mechanism for the gradual automatic re~

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, ~ ' ' ` ` 1048591 placement of a photoconductor belt used in photocopy machines.
It is still further an object of the invention to provide a --~
convenient method and apparatus for extending the lifetime of a photoconductor belt in a photocopy machine.
In summary of the above, the present invention provides a method for effectively extending the lifetime of a photo-conductor belt used in a photocopy machine comprising the steps I - of: moving the photoconductor belt around a belt path for the exposure to an image of an object followed by the development of the image on a sheet of paper; incrementally replacing the photoconductor belt with fresh segments to gradually replace the photoconductor belt around the belt path; and storing a supply of fresh photoconductor material in connected relation-ship with the photoconductor belt for movement therewith around ~;
; the belt path and wherein the incremental replacing step further includes the step of: removing the incremental segments from the supply of fresh photoconductor material ^ I
1 The above method may be carried out by a photoconductor j belt assembly for a photocopy machine comprising: a photoconductor

3 20 belt shaped to fit around a photoconductor belt path and adapted to move along the path in a photocopy machine, the photoconductor belt having a replacement segment to form a belt length in excess of the path length to enable a replacement of used photoconductor belt segments; a photoconductor belt cartridge connected to the I photoconductor belt and mounted to move therewith along the belt $ path, the cartridge having a photoconductor supply for the replacement segment of the photoconductor belt and having a photoconductor storage element to store used belt portions; the cartridge being relatively shaped to enable continuous motion of i 30 the photoconductor along the belt path.

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:~ ` lV~8S91 : Brlef Descrl~tion of Drawln~s - These and other advantages and objects of the inv~ntion ~ '-,~, can be understood from the following detailed description of , a preferred embodLment which is described in conjunction with .
the drawings wherein Fig. 1 is a side schematic and partial section view of ~--. a photocopy machine of the photoconductor belt type in accordance , i ' with the invention; ' ~:
,, Fig. 2 is a perspective partially broken away view of a roller and photoconductor assembly in accordance with the invention; ~ -~: Fig. 3 is a partial side view taken parallel along the axis of rotation of a roller employed in the roller assembly ; shown in Fig. 2:
Fig. 4 is a section view of a roller and its recess , with a cartridge of a photoconductor belt located in the recess iiJ for sequential rotational positions of the roller; , Fig. 5 is a partial section view of a roller taken along the line 5-5 in Fig. 3; ~:
Fig. 6 is a top plan view of a portion of the photo-conductor belt and cartridge shown in Fig. 2;

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~ mb/~ 8a - ' ~ 1~)48S91 ; Fig. 7 is ~n end view in eleyation of the photocon-ductor belt and cartridge shown in Fig. 67 Fig. 8 is a side view o~ the photoconductor belt and cartridge as shown in Fig. 7;
Fig. 9 ~s a section ~iew of the photoconductor belt cartridge as taken along the line 9-9 in Fig. 7; and Fig. 10 is an enlarged section view of the photocon-ductor belt cartridge taken along the line 10-10 in Fig. 8.
Detailed Description of Embodiment ~it~ reference to Figs. 1 and 2, a photocopy machine 20 is illustrated with a photoconductor belt 22 mounted for move-,m,ent along the direction of arrow 23 around a roller assembl~ 24 which æfines a belt path 26.
' Photocopy machine 20 employs various well-known oper- ~ ' a,t~ng components which are schematically illustrated. Thus, ! around belt path 26 are a photoconductor charging device 28 `I located just ahead of a generally flat photoconductor exposure section 30 where an optical lens system 33 forms a latent image '~
o an object ~not shown).
Exposure of the flat photoconductor section 30 is obtained with illumination from a high intensity flash source , (not shownl. Flash sources and their associated flash initiat- ' -ing circuitry are generally well-known in the art and, there-~ fore not ~llustrated. Upon exposure of the photoconductor belt j 22 at a flat region 30, a latent image of the object is formed and de~eloped b~ the applicat~on of toner particles from a suppl~ 32 with a magnetic brush 34. The toner particles then a~e transferred to a sheet of paper 36,at a transfer station 37, ~ ~a~er ~eed $tat~on 38 provides sheets 36 one at a time ~,ro,m, a ~ta,ck 40 for contact w~th the toner particle covered ~hotoconductor 22, ' After transfer of the toner image onto a sheet of cb/

1~48591 ;

paper 36, the latt~r is se~arated ~rom the photoconductor belt 22 and adyances past a heat source 42 whic~ ~uses the toner parti-cles into the sheet o~ paper. A charge ellminator 44 in the form o~ a light source is provided to expose the entire photoconductor belt 22 and facilitate subsequent toner removal with a brush 46 and yacuum toner remover 48. After passing of tlle belt cleaner 46, the photoconductor belt 22 may be again used for making a cop~ of an object. The actuation of the various components are properly timed with suitable switches operated in a sequence needed to complete a copy cycle. The circuitry and switches ~or such timing are also known in the art. A motor and drive ~echanism for moving the photoconductor belt 22 around the ~oller assembly 24 are also known and, therefore,,have been delet-ed for clarity of the drawings.
The roller assembly 24 is shown formed of three rollers 50.1, 50.2 and 50,3 ~rranged in a generally triangular fashion ~lt~ough dif~erent roller arrangements may be accommodated depend-~n~ upon the type of photocopying machine being built. The roller assembly 24 is supported by a suitable frame which was deleted ~ . . .
" 20 for clar~ty of the drawings. Each roller 50 rotates about an ax~s and shaft 52 which are parallel for all rollers 50. Roller ' 50,3 is shown spring loaded by a spring 53 to maintain tension on photoconductor belt 22 and impart so,me resiliency to the roller assembly.
The photoconductor belt 22 carries a replacement seg-~en~ located in a cartridge 54 which moves with belt 22 around " ~cllers 50 and thus the entixe belt path 26. One end o~ the p,hotoconductor belt 22 is connected to a supply reel 56 in cart-~id~e 54. Supply reel 56 carries a rolled up replacement segment 58 ~ee ~ig, 91 of the photoconductor belt 22. The other end o~ ~he photoconductor belt is connected to a take up reel 60 ~n c~tr~dge 54, The take~up reel 60 serves to store used seg-. ' cb/ - 10 -1~48591 ,~ ment of photoconductor material. The fresh and used segments o~ the photoconductor belt are'passed throu~h approPriate slits 62r 64 Csee also Fi~. 9) ln the cartridge 54. A slit cl~sure , ele~ent 66 Csee also Fig. 9) is provided to inhibit toner parti-;` cles ~rom entering the inside of caxtridge 54.
The cartridge 54 is ~ormed of a generally light-weight - ~m~aterial, such as plastic, so that the photoconductor belt 22 y support the cartri,dge 54 and its contents without undue or operationally signi~icant physical distortions of the photo-10 conductor produced by excessive tensions, bends or flexure :
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,,- The photoconductor belt 22 and its attached cartridge ~1 54 ~qr~ a unified assembly which is replaced in its entirety " when the photoconductor belt has been used. - ' ~, Since the cartridge 54 is located on the inside of ,~ the photoconductor belt path 66, the passage of the cartridge over " , ~i, the rollers 50 is accomplished wlth a cartridge receiving recess ''J.'l -70 i,n each of the rollers 50. T~e cartridge position along belt path 26 is selected ~n such manner that as the cartridge 54 app-,roaches a roller 50, a synchronized meshing with the roller ,; rece~ving recess 70 for entry thereof is established. In this anner the photoconductor belt 22 may be continuously moved ', around the path 26 while the belt is kept sufficiently taut., , Each recess 70 is normally covered with a pair of '' doors 72-72' that may be locked into a closed position with a loc~ing mechanism 73 located at each axial end of a roller 50.
' The covers 72 are curved to provide a continuous peripheral sur-$ace ~th the cylindrical surfaces 75 of rollers 50.
'";j The mounting of the photoconductor belt and cartridge 3~ as~e~bl~ is establis~ed w~tn precise synchrQnization relative , t~ t~ roller receisses 70 so that the cartridge 54 will properly ,' enter a recess 70 during belt motion. In addition, the rotations .. .
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of the rollers 50 are synchronized with each other with a pair of axially end located timing belts 74-74' spanning the helt path 26. Timiny belts 74 couples to axially end located timing ring gears 76-76' on each roller 50. The mounting of the photoconductor ~ belt 22 and cartridge 54 with timing belts 74-74' on the roller ; assembly 24 may include a collapsible assembly as shown, for example, in the art, U. S. Patent to Gardner et al, 3,521,950 ~ and those sect.ions thereof dealing with a roller assembly module .~ as shown in Fig. 1~. Thus a roller 50 may be moved inwardly to enable one to fit the photoconductor belt around the belt path.
The photoconductor belt 22 and cartridge 54 are locat-ed between the timing belts 74 as can be seen in the views of Figs. 2 and 6. The cartridge 54 is attached to the belts 74 with ,: .
an extension bracket 78. Bracket 78 may be attached to timing belts 74 at different locations by adjusting wing clamps 80.
Such lengthwise adjustment thus enables precise registration . and proper synchronous arrival of the cartridge 54 relative to recesses 70. Appropriate alignment indications are provided on belts 74 to aid the desired registration of cartridge 54 relative to rollers 50 and their recesses 70.
A dçsirable feature of the photoconductor belt assem-bly in accordance with the invention resides in the ability to . replace deteriorated photoconductor belt segments in an automatic continual manner. A belt replacement drive 82 (see Figs. 6, 7 and 8) is mounted on the cartridge 54 and coupled to the take-: up reel 60 to cause an incremental rotation thereof with each complete cycle of the photoconductor belt 22 about path 26.
The drive 82 is formed with a stationary pin 84 mount-ed to a frame ~not shown) near the path along which the cartridge 54 travels. The stationary pin 84 engages a Geneva mechanism 86 on caxtxidge 54 formed of a maltese cross shaped actuator 88 hav-~ng four corner located slots 90 arranged to engage pin 84, The cb/ - 12 -.
, ' ' ' ' : -1~4~591 , actuator 88 is connected to ~ pinion 92 which is coupled throu~h reduction gearing $ormed of a spiral gear 94 to the shaft o~ take-', up reel 60. -,' - Hence, as the photoconductor belt 22 ~s driven around ,' the belt path 26~ pin 84 is caused to eng~ge a slot 90, thus causing a one-quarter turn of the actuator 88 and its connected ', pinion 92, The speed reduction obtained between pinion 92 and , spiral gear 94 reduces the rot~tional drive of the take-up reel ., .
- 60 to a sm~ raction of an inch.
~- 10 The incremental advance of photoconductor belt replace- ' "~ ,m,ents by the take-up reel 60 is selected on the basis of the number f, ~ualit~ copies that can be made with any one segment of the photoconductor belt 22. For example, if one can make five thousand ~, qualit~ copies which are ten inches long, as measured along path "," 26, then after five thousand cycles ten inches of photoconductor material must have been replaced. This would require at least ,1 ;~.!' 0'~ 002" Ctwo thousandth's of an inch) effective take-up belt or 'l ,replacement motion ~y take-up reel 60 for each cycle. If actuator ' -88 under~oes about o,ne-quarter inch rotational motion, a speed x~duction of about one hundred twenty-five to one ~125:1) is need-,~ ed to establish a precise .002" incremental belt replacement.
~hen an advance or replacement of the order of .005" for each Cycle ~s néeded, the reduction ratto becomes of the order of :'!
'l fifty to one ~S0:11.
: , Actually, the-incremental replacement introduced by t~e ~ctuation of th~ Gene~a,mechanlsm 86 will v~ry depending upon the effective xadius of the take~up reel 60. Thus initially the ~ncxemental adyance may be so~ewhat less than .002" while the ' '' a,dva,nce ~ ncrease as,m,ore photoconductor belt iswound onto t,a,ke-up reel 60.
,; The total amount o~ photoconductor belt material that ' can be $tored by cartridge 54 determines the effective lifetime cb~ - 13 -... . . .
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;, of the entire belt assembl~. Since replacement is carried out on a continual basis~ i.e. by small increments measured in frac-tionS of an inch~ the quality of the copies w~ll be generally çonsistent. The incremental advance may be varied depending . ~
~pon the t~pe o~ photoconductor m~teri~l and the acceptable level ' Qf ~u~lity. The range o~ incremental advances may vary, by selecting the reduction ratio, or by altering the diameter of the take-up reel 60 or by producing an incremental advance for eyery two or several number of cycles or combinations thereof.
Generally the incremental replacement is selected small in compari-s,on with the length of the image or the length of the photo-cQnductor belt path to enable the gradual photoconductor belt replacement.
The incremental advance or replacement of the photo-~onductor is particularly advantageous in distributing physical l~ading such as may be caused at bending points. Thus, the entry and departure of the cartridge 54 relative to a roller recess 70 may'involve shape changes whose damaging effects on the photoconductor tend to be reduced by its,continual replace-,ment, The incremental replacement of the photoconductor i~s preferabl~ of such small amount that the initial resulting inc,rease in tension ~s neglig~ble. The small additional take-up tends to be d~stributed over the entire photoconductor belt 22 as the latter with its cartridge 54 is moved through a copy-~ng c~cle over the various rollers 50.
The ~uantity of fresh photoconductor belt material on the su~ply reel 56 is selec'ted to achieve a desired total copy-~,n~ capability ,~or the belt and cartridge assembly. The maxi-mum sto~age o~ photoconductor belt material within the cartridge 54 ~ust be limited to mainta~n the cartridge s~ze to enable its pasSage past rollers SO.
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As shown in Fig. 9, the cartridge 54 includes a pair of output idlers 100~ 100' which are located adjacent slits 62, , 64 ~espectivel~, Idlers 100 facllitate the transfer of photo-conductor belt 22 out of and into the cartridge recess 102.
The supply reel 56 is mounted wtth a friction disc 104 (see Flg. 10) adjacent an ax~al end to inhi~it free rotation of supply ~eel 56 and provide a minimum amount o~ tension in the photo-conductor belt 22. Other restraining elements could be used such as a spring loading of supply reel 56. The rotations of Supply reel 56 and take-up reel 60 are in the directions indicat-~^ ... .
ed b~ arrows 106-106'.
The arrival of the cartridge 54 at any one of rollers 50 is accompanied by an opening of doors 72. The respective mechanisms for accomplishing the insertion of the cartridge 54 ~nto a recess may be conveniently exjlained with reference to ' Figs. 2, 3, 4 and 5. The timing belts 74-74' are each provided with cams 110~110' respectively formed of outwardly projecting , , ~stud~s 112 sized to engage locking mechanisms 73. Each locking , ~echan~,sm 73 is formed of an annular lever segment 114 extend-,~, 20 ing radially above the peripheral surface 75 of rollers 50 at ' ', axial ends thereof.
; ~ As shown in Fig. 5, the annular lever segments 114 a,re-provided with an axial bolt extension llS mounted to slide ~t,n the d~rèction of double headed arrow 116 below both doors ~2~72', A spring 118 which has an end 119 anchored to an end ~all 120 of rollers 50 urges each bolt extension into a door locking posttion a,s shown in solid lines in Fig. 5.
When the cams 110-110' arrive, generally at about the sa~e time, at roller 50, the front or forward cam studs 112 ~ engage annular lever $e~ments 114.114~ and gradually force t~e~ outwardly as the rollers rotate in the direction of arrow ~22 and t~e ~hotoconductor belt moves clockwise'in the direction Cb/ r 15 -~.. , ., : ' .
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10~8591 of arrows 23. By the ti~e the cartridye 54 arrives at a recess 70, the lockin~ bolt 115 will ~ay~ been cammed out to the posi-i tion indicated in dotted lines in Fig. 5, thereby enabling doors 70 to open inwardly.
Both doors 72-~2' are pivotally mounted at pivots 128 and urged in a closed position with springs 130-130' respectively to preserve the cylindrical shape of roller 50. As the cart-r~dge 54 arrives, it ~orces doors 72 open to their open position as shown in Fig. 4. When the cartridge 54 has fully entered -~ 10 recess 70, a pair of studs 132 arrest further inward movement.
Studs 132 are mounted on roller end walls 120-120' and extend axially into the cartridge recess 70 for a distance sufficient to seat the bottom wall of cartridge 74. Since, as shown in Fig. 4, doors 72 swing past studs 132, each door is provided ~ith end located cut-outs 134. These cut-outs are sufficient~y narrow, aS shown in Fig. S, to prevent affecting the photoconductor 22, Segments 136 of doors 72 are provided with axial extensions 138 which engage the outer wall of rollers 50 to firmly seat d~ors 72 in their closed position.
The annual extended shape of the lever segments 114 ~is provided to assure an unlocking or released position of the ~olt SegmentS 115 throughout the passage of the cartridge 54 past a roller 50. As shown in Fig. 4, the length of cam 110 or ' number o studs 112 is selected to maintain cam contact from the time a cartridge enters a recess 70 until the time it has le~t a recess. As a result, the bolt segment 115 will remain open until the doors 72 haye been ~eclosed and then slides in under pressure ~rom springs 118 to lock the doors in their closed position.
` 30 As shown ln Fig. 4, the entry of cartridge 54 into ~eces~s~ 70 o~ roller 50 is accompanied with a readjustment of t~ photoconductor belt 22, Thus when cartridge 54 is seated cb~ - 16 ~

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on studs 132, a straight se~ment 140 of belt 22 is ~ormed between cartridge 54 and th~ ed~e 142 o~ the peripheral wall ~f roller S0. The'photoconductor thus undergoes shape changes its cartridge is moved past a roller. Since any one belt section is gradually replaced, ~t will not ~e sub~ected to excessive stresses over an extended time; hence, any discontin-uities presented ~n the photoconductor belt, such as when cart-~idge 54 is mo~ing past a roller 50, can be tolerated.
The operation of the photocopying machine 20 includes ~uitable t~ing controls to preferably expose the photoconductor belt 22 at the ~ost appropriate time. Thus when the cartridge 54 is in transit between rollers and the closure elements oper-ati,ve with recesses 70 assure a firm cylindrical surface of rollers 50, belt 22 has a generally constant tension force and ~i,s ~ree from disturbances to enable the formation of an unblurred ' latent image. In a similar manner, the transfer of the toner particles ~rom the latent image onto a sheet of paper is timed to occur when the photoconductor movement is steady.
The operation thus includes a continuous movement of' the photoconductor belt around the belt path while it is being gradually replaced by the incremental take-up action of the ,, take-up roller. The incremental advance may vary in size, ~epending upon the number of rollers, the size of the take-up Qller and the replacement rate of the photoconductor.
Having thus described a photocopy machine in accordance ith'the invention, its advantages may be appreciated. A belt ph~toconductor of a relatively low copy producing capability per un~t length ma~ be used with flash exposures, yet with a long over~all effective lifetime. The gradual replacement of the Rhotoconductor provides a convenient method to assure a h ~ h ~ualit~ o~ copi,es~

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Claims (31)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A photoconductor belt assembly for a photocopy machine comprising a photoconductor belt shaped to fit around a photo-conductor belt path and adapted to move along said path in a photocopy machine, the photoconductor belt having a replacement segment to form a belt length in excess of the path length to enable a replacement of used photoconductor belt segments, a photoconductor belt cartridge connected to the photoconductor belt and mounted to move therewith along the belt path, said cartridge having a photoconductor supply for the replacement segment of the photoconductor belt and having a photoconductor storage element to store used belt portions, said cartridge being relatively shaped to enable continuous motion of the photo-conductor along the belt path.

2. The photoconductor belt assembly for a photocopy machine as claimed in claim 1 and further including means associated with the storage element to provide incremental photoconductor stor-age movement in addition to said belt movement during passage of the photoconductor belt along the belt path.

3. A photoconductor belt assembly for a photocopy machine as claimed in claim 2 wherein said additional storage movement producing means includes an actuating element operatively associat-ed with the storage element to provide an incremental storage movement thereof measured in the order of a fraction of an inch.

4. A photoconductor belt assembly for a photocopy machine as claimed in claim 1 wherein said cartridge is further provided with attaching means to enable a predetermined registration with the belt path upon operative mounting of the photoconductor belt in the photocopy machine.

5. In a photocopy machine wherein a photoconductor belt is employed with a belt replacement segment on a belt supply element and a belt-take-up element for storing used belt segments, the improvement comprising a roller assembly arranged to define a photoconductor belt path in the photocopy machine, the roller assembly further being provided with spaced rollers arranged to enable the photoconductor and a cartridge retaining the belt replacement segment to pass around the outer peripheries of the rollers, each roller being provided with a cartridge receiving recess shaped to receive the cartridge during its passage to enable smooth movement of the belt along the belt path.

6. The roller assembly for a photocopy machine as claim-ed in claim 5 wherein each roller further is provided with means for closing the cartridge receiving recess to form a substantially continuous peripheral roller surface whereby the photoconductor belt along the belt path is maintained generally taut when the cartridge is located away from the cartridge receiving recess.

7. The roller assembly for a photocopy machine as claim-ed in claim 6 and further including means for aligning the photo-conductor cartridge with the roller recesses to enable the cart-ridge to enter a recess in a roller during passage of the cart-ridge passage past the roller.

8. The roller assembly as claimed in claim 7 wherein the aligning means includes a timing belt operatively coupled around the rollers to secure synchronized rolling thereof, with the cartridge of the photoconductor belt being coupled to the timing belt at a predetermined location therealong for proper meshing of the cartridge with each roller recess during movement of the photoconductor belt along the belt path.

9. The roller assembly as claimed in claim 8 wherein the closing means includes means for releasably radially locking the closing means to maintain the peripheral surface thereof in a continuous shape and means located on the timing belt at a preselected spacing from the cartridge for releasing the radial locking means during passage of the cartridge past a roller.

10. The roller assembly as claimed in claim 6 wherein the closing means includes a door pivotally mounted for opening move-ment inwardly into the roller recesss said door having an outward shape selected to form a continuous cylindrical surface with the roller periphery upon closure of the door.

11. The roller assembly as claimed in claim 10 wherein the closing means further includes means for normally biasing the door into a recess closing position, means for releasably lock-ing the door in its closed position to retain the continuity of the roller peripheral surface when the cartridge is located away from the roller.

12. The roller assembly as claimed in claim 11 wherein the means for releasably locking of the door further includes circumferentially extending segments mounted at axial ends of each of the rollers, with each segment having an axial bolt lever located to move axially towards and radially below the door, said segments being spring biased to lock the door and extending circumferentially for a distance sufficient to enable an opening of the door upon the arrival of the cartridge and a locking of the door upon departure of the cartridge from the recess.

13. In a photocopy machine wherein a photoconductor is employed with a replacement segment for replacing used photo-conductor material, the improvement comprising a roller assembly arranged to define a photoconductor path along which a photo-conductor belt is moved for producing a copy, the roller assembly being formed of a plurality of rollers arranged to rotate about parallel axes, each of said roller's having a cartridge receiving recess, a photoconductor belt shaped to fit around the rollers -along the path, the photoconductor belt being of a continuous length selected to include fresh belt replacement segments with the total photoconductor belt length being in excess of the path length to enable replacement of used photoconductor belt segments, a photoconductor belt retaining cartridge operatively associated with the photoconductor belt and sized to retain the fresh photo-conductor replacement segment and used photoconductor belt seg-ments, said photoconductor belt and cartridge being located to enable the cartridge to be received by each roller recess during passage of the photoconductor belt and cartridge past a roller.

14. The improvement for a photocopy machine as claimed in claim 13 and further including means for incrementally replacing the photoconductor with fresh photoconductor material from the cartridge.

15. The improvement for a photocopy machine as claimed in claim 14 wherein the cartridge is provided with a supply reel to store the fresh replacement segment of the photoconductor belt and take-up reel to store used segments of the photoconductor material said incremental photoconductor replacing means being effectively coupled to the take-up reel to obtain said incremental photoconductor replacement by winding up a corresponding used segment onto the take-up reel without loosening of the photo-conductor belt.

16. The improvement for a photocopy machine as claimed in claim 15 wherein the incremental replacement is measured in the order of a fraction of an inch.

17. The improvement for a photocopy machine as claimed in claim 16 wherein the incremental photoconductor replacing means further includes a Geneva mechanism mounted to the cart-ridge and coupled to wind up the take-up reel in the cartridge with said predetermined incremental movement, and an actuating lever located adjacent the photoconductor belt to engage the Geneva mechanism and impart a driving force thereto upon pass-age of the cartridge.

18. The improvement for a photocopy machine as claimed in claim 16 wherein the incremental photoconductor replacing means further includes means for activating the take-up reel to wind up an incremental used photoconductor segment each time the photoconductor belt has travelled a predetermined number of cycles around the belt path.

19. The improvement for a photocopy machine as claimed in claim 18 wherein the actuating means winds up the take-up reel an incremental amount each time the photoconductor belt has completed a pass around the belt path.

20. A high speed photocopy machine comprising means for defining a photoconductor belt path having at least one section where a photoconductor belt advances in a flat condition to receive a flash exposure of an image of an object and along which path the image is developed and transferred to a sheet to form a copy of the object, a continuous supply of photoconductor material in the form of a flexible belt sized to enable a usable segment of the belt to span the belt path, with the photoconductor material formed of a photoconductor having a limited useful life for the making of copies, a cartridge sized to retain a fresh supply of photoconductor material in excess of the belt length needed to span the belt path, with said fresh supply of photo-conductor material being coupled to the segment spanning the belt path for replacement thereof and extension of the time interval between the replacement of the entire belt, said cart-ridge being operatively associated with the photoconductor belt during passage of the belt along the belt path, means for pro-ducing a uniform electrical charge on the belt, means for exposing the charged photoconductor belt at its flat condition section for a short period of time to effect flash exposure of the photo-conductor belt while the belt is moving, the time and intensity of the flash exposure being selected to avoid formation of a blurred latent image on the photoconductor belt, means for developing the latent image on the photoconductor belt with toner particles, means for supplying individual sheets of paper into contact with the developed photoconductor belt for transfer of developed images to the paper, means for fixing the transferred image on the paper, means for removing residual charges from the photoconductor belt, and means for incrementally replacing the spanned photoconductor belt with a corresponding increment of fresh photoconductor belt stored in the cartridge following a preselected number of cycle uses of the photoconductor belt.

21. The high speed photocopy machine as claimed in claim 20 wherein the means for defining a photoconductor belt path includes a plurality of rollers located to define the belt path, said rollers each having a recess sized to receive the photoconductor cartridge during its passage around the belt path.

22. The high speed photocopy machine as claimed in claim 21 wherein the belt path defining means still further includes:
means for replacing the photoconductor with incremental fresh supply segments stored in the cartridge and with the increments being small in relation with the belt path to provide a gradual replacement of the photoconductor belt.

23. A method for effectively extending the lifetime of a photoconductor belt used in a photocopy machine comprising the steps of:
moving the photoconductor belt around a belt path for the exposure to an image of an object followed by the development of the image on a sheet of paper;
incrementally replacing the photoconductor belt with fresh segments to gradually replace the photoconductor belt around the belt path: and storing a supply of fresh photoconductor material in connected relationship with the photoconductor belt for movement therewith around the belt path and wherein the incremental replacing step further includes the step of:
removing said incremental segments from the supply of fresh photoconductor material.

24. The method for effectively extending the lifetime of a photoconductor as claimed in claim 23 wherein the incre-mental replacing step consists of replacing the photoconductor belt with segments which are small in relation with the photo-conductor belt path.

25. The method for effectively extending the lifetime of a photoconductor as claimed in claim 23 wherein the replacing step consists of replacing the photoconductor belt during its movement around the path with increments of the order of a fraction of an inch.

26. The method for effectively extending the lifetime of a photoconductor belt used in a photocopy machine as claimed in claim 25 wherein the incremental replacing step is selected in size commensurate with a desired number of copies and the type of photoconductor belt material.

27. The method for effectively extending the lifetime of a photoconductor belt used in a photocopy machine as claimed in claim 23 and further including the step of storing incremental used photoconductor segments in correspondence with the incre-mental replacement thereof.

28. The method for effectively extending the lifetime of a photoconductor belt used in a photocopy machine as claimed in claim 25 wherein the incremental replacing step is carried out each time the photoconductor belt has moved a predetermined number of times around the belt path.

29. The method for effectively extending the lifetime of a photoconductor belt used in a photocopy machine as claimed in claim 28 wherein the incremental replacing step is carried out each time the photoconductor belt has moved around the belt path.

30. A photoconductor assembly for a photocopy machine comprising means for defining a photoconductor belt path having at least one section where a photoconductor belt advances in a flat condition to receive a flash exposure of an image of an object and along which path the image of the object is developed and transferred to a sheet to form a copy of the object, a con-tinuous supply of photoconductor material in the form of a flex-ible belt sized to enable a usable segment of the belt to span the belt path with the photoconductor material being formed of a photoconductor having a limited useful life for the making of copies, a cartridge sized to retain a fresh supply of photo-conductor material in excess of the belt length needed to span the belt path, with said fresh supply of photoconductor material being coupled to the segment spanning the belt path for replace-ment thereof and extension of the time interval between replace-ment of the entire belt, said cartridge being operatively associat-ed with the photoconductor belt during passage of the belt along the belt path, and means for replacing the photoconductor belt segment spanning the belt path in incremental segments and grad-ually replace the photoconductor with the fresh supply of photo-conductor material retained in the cartridge.

31. The photoconductor assembly for a photocopy machine as claimed in claim 30 wherein said means further includes means periodically actuated in response to movement of the photoconductor belt to store a used incremental segment thereof upon each actua-tion.