CA1064249A - Copying apparatus - Google Patents

Abstract

ABSTRACT

The present invention provides an improved electro-graphic apparatus which includes means for developing an electrostatic latent image on an image bearing member. The image is then developed with a liquid developer which includes toner particles in a liquid carrier. The supply of liquid developer is held in a container, and means are provided for circulating the developer between the container and the developing means. A filter is located in the path of circulation of the developer. As the developer contacts the filter during the operation of the apparatus coagulations of toner particles are dispersed.

Description

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This invention relates to a convenient copying apparatus which can fully function both as a sheet original copying apparatus and a thick original copying apparatus and which is capable of increasing the copying speed in accordance with the copy size and incorporates various devices for convenient use.
Copying machines have heretofore been classified into two types, namely, those for copying sheet originals exclusively and those capable of copying books or other three-dimensional originals.
; The copying machines exclusively for sheet originals cannot copy booXs or other thick originals but they can produce ; copies of sheet originals simply by inserting sheet originals -t; , ;j into an inlet port and for one and the same process, these machines involve no copying stroke of the original carriage or . j, : . .
~; the optical system and can correspondingly increase the copying - -~ speed (by approximately two times). Further, the mechanical ,~, , . j ,, constructions are simple and this leads to economical advantages of the machines. Also, the copying machines of this type readily permit inclusion of autofeeder devices for originals.
;l In contrast, the copying machines capable of pro-ducing copies of books or other thick originals have a great `
. advantage that they can copy sheet originals as well as books or like originals, but inasmuch as these machines are designed ~`
such that any original to be copied must be flatly spread over the original carriage, a sheet original as well as -., . :
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e~ 10~j4'~49 Ll t~ l~ o~ ] ~.,s to ~ LIC~d on thc gl~9 plat~ o~ ttlO
2 originLIl ~rria~ ~y ~ nu~lly rai~ g ~n origin~l keep cov~r an~ th'-`~l closi~lg tl~ covcr~ whcreartcr a copy button mu~t be 4 depress~d to ~frc~t ~opying. ~`urther, the original carriaee or the optic~l sy~t~lll in the~e machincs has the copying stroke, 6 which means a corrcsponding loss of timc, and thus the copying speed is necessarily r~duced f`or one and the same process.
8 Moreover, complicated mochanical con~tructions lead to hi6h~r 9 cost of the machines. ~urther, it is very difficult to provide these machines with autofeeder devices for originals.
11 For the reasons set forth above, the two types of 12 copying ~achines enjoy their own markets.-13 In mo~t offices, however, demand concentrates on 14 copies of sheet originals rather than copies of thick originals.
Therefore, users have been compelled to purchase more expensive 16 thick original copying machines at the sacrifice of the 17 expediency of the sheet original copying machines. To overcome 18 such inconsistency, there have been devised some copying machines which retain the features of sheet original copying machines and are still capable of copying thick originals as 21 well. These include the following types:
22 I. The type wherein the portion of the machine which 23 is above the passage surface for sheet original is removabl~ ;
24 and for the production of copies of a thick original~ such portion is removed to expose the sheet original transport roll~ !
26 in the machine body so that the thick original is manually 27 urged against the rubber rolls~ which transport the thick 28 original for slit exposure; and 29 II, The type which is similar in construction to the

3 type I, with the exception that a carrier comprising a - 3 ~
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1~64Zg9 1 trw~ r~ tic~ or lik~ material i~
2 preparc~ oll W}liCIl ~ t~lic~ origin~l may be placcd and tuo or 3 nlore p~ir~ r~ rt roll~ h~ld tllorebctw~ n the ~nd~ uf

4 carricr to tr~n~port th~ carri~r for exposure.
Sincc thc~e m~chincs ~re vcry little different in 6 mechanical con~tructiorl i`rom the ~heet original copying 7 machine~, they ~re n~t ~o expensive, wher~a4 any of them 8 sufrers from thc di~dv~ntage~s as follows:
9 (1) On the part of users, it is considerably cumbersome to remove a portion of the machine and 11 a limited office sp~ce would offer a problem Or 12 finding a space for the removed portion.
13 ~urther, the method II above would offer problem~
14 in storing the carrier.
(2) In the method I above, a great load variation 16 would occur with respect to the machine body 17 depending on the manner in which the original is 18 urged, and in the method II above~ the thickness of the carrier would cause a corresponding variation in the length of the optical path~
21 which would result in improper focusing and . ~ ~
22 accordingly a corresponding error of periodic 23 speed, thu~ greatly aggravating the quality of 24 resultant copy images.
(3) A gear and sprocket wheel arrangement for driving 26 the original transport rolls at the end thereof., 27 and in the method II~ the carrier transport rolls, 28 are pro~ected upwardly beyond the original ~9 transport surface and such surface cannot be made fl-t, thus making it impossible to copy a part of ~3 1064Z49 .1 ~s' 1 a lar~e-si~cd originul.
2 (4) Wher~ the original to b~ copied is a book or t~le 3 likc h,vin~ a ~ubstantial thickness and havin~
4 the leading edge thereof (as viewed in the direction Or transport) complicately configured 6 (due to the presence of a book cover or the 7 inclined edge surface resulting from the opened 8 position of the book), an edge detector switch 9 for detecting the leading edge of sheet original is used to detect the leading edge of the book 11 and this results in appreciable irregularities of 12 the leading edge position in the resultant copies.
13 Thus, the above-mentioned types of machines are hardly available -~ 14 for practical use and the above-noted features could only be the I -1 15 sales points, at best.
16 It will thus be noted that these conventional 17 copying machines cannot be said to be completely practical.
18 However~ R9 an improvement over the prior art~ the following 19 system has been proposed and successfully put into practice.
According to this system, an electrophotographic 21 copying machine o~ the movable carriage and slit exposure type 22 i8 constructed such that a movable original carriage and a 1 23 sheet original transport portion comprising two or more pairs ! -1~ 24 of rolls have ~heir exposure surfaces in the same plane and the l~ 25 original carriage and the sheet original transport portion are 26 integral. To produce copies of a sheet original~ the ori~inal ~ 27 may be inserted into the sheet original transport portion and ¦~ 28 thereby moved to an illuminating portion. ~hen copies of a 29 book or other thick original are to be produced, this system is 3 highly useful because it has overcome the above-noted various

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1 di~ad~rwlta~-S. Ilow~v~r, ~pplication Or such ~ystem to thc 2 co~ying ~achincs ror t~l~ pro~uction of largo-~ized copie~ woul~
3 encounter th_ r~llOwil,~ o~er~ti~,n~l un~ t~cl~ical pr~bl~
4 1) It is dirricult to insert a ~heet ori6in~1 of large sizc into tho sheet original inlet port

6 becau~e the insertion Or sheet original mu~t be

7 done hori~ontally; and

- 8 2) The movable original carriage is so hoavy that smooth reciprocation thereof is difficult.
With regard to developing device, liquid development i 11 is superior to dry development in that it is higher in .~ 12 developing efficiency and can provide better image reproduction.
i1 13 On the other hand, liquid development is delicate in developing -~ 14 action ~nd therefore, cumbersome procedures are required in i5 construction of the portion in which the photosensitive medium 16 is contacted by developing liquid, and maintenance of the toner :~ 17 density of the liquid and the circulation system therefor as 18 well as periodic servicing or inspection is imperative.
19 Particularly, the developing electrode portion is provided with various mechanisms for ensuring production of ~;
21 good copies, such as a scraper for removing stains on that side ~22 of transfer paper adjacent the separator belt and a fog j 23 removing roller for removing any fog from the trans~er paper, ~ 24 and these mechanisms require periodic servicing or inspection d .~ 25 and would sometimes require replacement of parts~ di~assembly 26 and/or cleaning.
27 . Further, if the widt}- o~ transrer paper is lncreased~
28 the width of the developing electrode will also have to be 29 increased and this will unavoidably lead to an increased size ¦ 30 ¦¦ of the dev 1 per container on whloh thu devoloplng electrode -6_ .'`
~, I , ' 10~4'~ 49 i.s mounte~l.
2 The increascd si~e Or the devcloper container means a 3 correspondill~ly incro.lsed qualltity of developing liquid therein, 4 which woulcl prevollt sufficicnt agitation of the developing liquid, th-ls reducing the friction~l charging efficiency of 6 toner and carrier in the developing liquid.
7 If powerful agitation is effected to enhance the 8 agitating efficiency, the agitation will increase the

9 temperature of the developin~ liquid to thereby increase the amount of developing liquid consumed due to natural evaporation 11 of the liquid.
12 When copying operation is started after a long 13 down-time, liquid agitation cannot sufficiently be achieved in 14 a short time, as a result of which first several copies would be low in contrast. Also, the developing device itself would 16 become larger than size A2 (420 x 594mm) and accordingly 17 heavier in weight and therefore, if the developer container and 18 the developing electrode were constructed integrally with each 19 other as described, the developing device would become inconvenient to take in and out of the machine body and 21 difficult to service and inspect.
22 During down-time of the machine~ developing liquid 23 tends to evaporate and toner in the carrier liquid readily 24 solidifie~ into toner masses, which may mix with the circulating developing liquid and be supplied to the developing electrode 26 portion to create unevenness of the resultant copy images or 27 injure the photosensitive medium.
28 Also, in the electrophotographic art using liquid 29 developer to develop electrostatic latent image, there has 3 hcretofore been a devoloping device which comprises a developer ~ ~ ~,064Z49 1 1 cont~ ing portion for containing the developer therein and a ¦ 2 developillg I)ortion for developing an object to be developed on a photo~ensi~ive mediulll or the like, the developer containing 4 portion and the developing portion being individually ~, constructed with a distance therebetween. In such device, the 6 developing portion and the developer containinf~ portion have 7 been connected together by pipes or other connecting means so 8 that the developer may be supplied from the containing portion 9 to the developillg portion and collected from the latter into the former portion. For the purposes of maintenance~ repairs, 11 inspection or the like, removal Or the developer containing 12 portion or the developing portion must be done either by 13 excepting the connecting pipes or by simultaneously removing 14 the two portions unstably connected by the thin pipes. In the first-named case, one end of the excepted pipes would interfere 16 with the removal of the portion to be removed, and developer 17 would even leak through the disconnected pipe end to contaminate 18 the device. In the latter case, simultaneous removal of the 19 two portions connected by the thin pipes i9 a difficult work and, even if only one of the two portions i9 to be removed~ both 21 portion~ need be removed and this is a wasteful and time-22 consuming work.
23 For the detection of the density of bhe developing 24 liquid in the developing device of the copying machine, use has been made of photoelectric detector means which comprises a 26 light source or lamp and a light-sensing element. However, such 27 photoelectric clotector means simply immersed in the developing 28 liquid may often have its dctecting function reduced by toner 29 which tends to precipitate and solidify to stick to a wall 3 portion correspondlng to the optical path of the photoelectric ., I
~(~4~49 ~ dCtOCtOl` m(`.ll)~. In ~IIIOt)lCI' prior ~rt a~rangement wherein the 2 photocl~c~tric ~l~toctor mo~ is ~ispo~ed outside tlle developer 3 container al~ ly ~f dcYolol)ill"r li(luid is effected by 4 pUII~pillg me~l~, wllcn t~ copyin~ machi~c has been stopped from operating, dcveloping liq~lid raroly stays in the detector means 6 so that tl;c surf~ce Or a tr~n~p~rent member accommodating 7 therein tllc lig~lt source and light-~ensing element i9 dried to 8 permit residual toner to stick to said surface, thus rendering 9 accurate detection of the density of developing liquid

10 impossible.

11 In the drving-fixing device of copying machine, a heat

12 source commonly used is a heating plate which comprises a plate-

13 like nichrome wire wound around a flat mica plate and having

14 the opposite surfaces covered with layers of mlca for

15 insulation, the heating plate being urged against a metal plate

16 of good heat conductivity to heat the metal plate. Since,

17 however, the mica as the insulating material is hard, it is

18 difficult to bring such material into intimate contact with the

19 heating plate and this is particularly so when the heating plate

20 has a complicatedly curved surface configuration. Therefore,

21 poor heat transfer may occur in the area~ of non-contact

22 between the plate-like heater and the heatlng plate and the

23 portion of the nichrome wire in such areas may often be

24 overheated and broken. Further, unless the heating plate

25 directly contacted by copy medium, for example, paper, has a curved surface deYigned well in view of the properties of th0 27 paper when hcated and the configurations of the passages before 28 and after thc heating plate, the contact betwecn the paper and 29 the heating plate would be worse to reduce the heat transfer 30 efficiency thorobetweon.

1 In thc convcntionally usc~ heating plate type heater 2 structurc wllich comprises a convex-surfaced heating plate, a 3 plate-like hcater ~nd a support plate having a convex ~urface 4 similar to that of the heating plate and wherein the heater is brought into intimate contact with the heating plate by bolting - 6 it to a bottonl plate integral with the heating plate, the ~imple 7 convex configuration of the heating plate permits the plate-like 8 heater to be well brought into intimate contact with the 9 heating plate by adjusting the fastening force of screws in use. However, if the screws are too much tightened, the heating 11 plate will be deformed or the support plate will be deformed by 12 the repulsion of the plate-like heater, thus adversely affecting 13 the contact and causing the above-noted disadvantages. If the 14 thickness of the heating plate and of the support plate is increased to prevent the deformations thereof, their heat 16 capacities will be increased to increase the time required for 17 them to attain a predetermined temperature. Thus, the heater 18 structure now under discussion is hardly applicable to the heat 19 plate having surfaces concavely and convexly curved in accordance with the properties of paper and with the 21 configurations of the passages before and after the heating 1` 22 plate.
, 23 Further, in the development process of the wet type î 24 electrophotographic copying machines, solution of hydrocarbon 1 25 is used as carrier and some amount of such solution remains on , 26 the surface of copy paper onto which a toner image has ~ust been t 27 transferred from the photosensitive drum, In the drying-fixlng 28 devices of the type which fixes the toner image on the copy 29 paper while evaporating the residual hydrocarbon, it is required 3 that the heat from the heat source be efficiently transferred to - 10 - '., 'i'`

-o 1~64'~49 1 t~lC copy p.~ r.
2 Such dryin~-fi~illg devices include a) those which 3 use infrare~ ray l~lm~s; b) those which utilize a blast of hot ?
wind; and c) those which em~loy heating plate~. Type a) suffers from disadvantages resulting from heat scattering, 6 temper~ture rise in the machine and adverse effeet of infrared 7 rays on tlle image transfer device. Type b) is low in drying 8 efficiency and requires the copy paper transport passage in the 9 drying-fixing device to be longer, which in turn leads to a large size of the device.
11 Type c) is such that the heating plate is heated to 12 about 230C by a heater and copy paper is advaneed over the 13 heating plate with the back side thereof in contaet therewith 14 for drying and fixing, and if a good contact i9 provided between the heating plate and the copy paper the device of this type may 16 be small in size and light in weight to aceomplish the drying 17 and fixing with a very high effi¢iency.
18 Nevertheless, the properties of copy paper which will 19 be warped when heated make it very difficult for such eopy paper to advance while maintaining a good contaet with the heating 21 plate, and there is another problem that the distance of 22 transport on the heating plate cannot be so long because of the 23 requirement for reduced size of the device.
24 Also, in copying machines, special attention is paid to the design thereof so as to prevent jamming of eopy paper in

26 the interior of the machine, but should ~amming oceur~ removal

27 of the jammed paper must and can be done with ea9e. ~or thi9

28 purpo~e, it has hereto~ore been praetised to provide the eopy

29 paper transport passage by divided sur~aees to theseby pern~it 3 the eopy paper transport portion to be divisibly eonstrueted.
` ~ ' ' . i ~ ~ ~__ _ ~ , ' . ' ~064'~49 owever, various factors may cause copy paper to be jammed as it is transported in a narrow passage. Thus, a design for reducing the frequency of jamming is necessary and at the same time, a construction is necessary which will readily permit removal of jammed paper whenever it occurs.
Further, the copy paper feeder bed of copying machine has heretofore been designed such that it can carry thereon and supply therefrom a plurality of sizes, including a maximum size and lesser sizes, of copy mediums in accordance with the per-10 formance of the machine.
However, as when one side plate of the paper feeder bed is displaced to match a small size of copy paper, the distance between springs and paper feed roll which produce paper feeding forces differs from one side to the other side of the feeder bed, ; and this in turn leads to different pressure contact forces and accordingly different feeding forces on the opposite sides, with a result that copy paper is fed obliquely.
Also, confirmation of the sizes of copy paper carried on the feeder bed must be directly done by manually opening a lid 20 such as outer plate or the like.

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With a view to alleviating the problems of the prior art devices, the present invention providesan electrographic apparatus, comprising means for forming an electrostatic latent image on an image bearing member, developing means for developing said image with liquid developer comprising toner particles in a liquid carrier, a container for holding a supply of said liquid developer, means for circulating liquid developer between said container and said developing means and a filter located in the path of circulation and arranged so that developer falls into contact therewith, in operation of the apparatus, such that .~ coagulations of toner particles may be dispersed by engagement ~ :-. with said filter. ,~
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The electrographic apparatus of the present invention provides a mirror in the optical path for image formation may be moved to selectively form two optical paths, one for sheet original and one for thick original such as book or the like, so as to enable either of sheet original and thick original to be simply copied.
In the developing device, the developer container and the developing electrode portion are constructed separately and connected together by pipes and the developing electrode portion is coupled to a member slidably fitted to a strut provided for reinforcement of the copying machine body, so that the developing electrode portion may be slidden along the strut so as to be withdrawn outwardly from the machine body for servicing or inspection.
Further, only one end or a predetermined portion of the supply and collection pipes connecting the developer con- `
taining portion and the developing portion may be removed to pro-vide the following connections. That is, the supply pipe 10~ 4'~

of the developer containing portion may be connected to the collection port of the container (or the collection pipe of the developer containing portion may be connected to the supply port of the containing portion) and in the developing portion, one end of the collection pipe thereof may be connected to the supply port of the developing portion (or one end of the supply pipe of the developing portion may be connected to the collection port of the developing portion).
In the developing device of the present invention a path is p~ovided between the portion of the developing device -which develops the electrostatic latent image and the developer container to permit circulation of developing liquid therebetween.
In such path, there may be provided a member for impacting and ; dispersing toner masses solidified in the developing liquid. This member may serve not only to disperse toner masses but also to remove dust or other impurities in the liquid or to fully filtrate -~
the liquid. As an example of the method of dispersing toner ~ -masses, the developing liquid in the developer container may be pumped to the developing portion, whereafter the head between the - -~ 20 developing portion and the developer container may be utilized to ; cause the developing liquid to fall toward a filter formed of an aggregate of fibrous material or thin parallel metal plates or a metal netting or the like so that the impacting force of the liquid may disperse toner masses.
In the density detector device, a pumping mechanism including an impeller and a casing forming a spiral chamber is provided in the developing liquid, and the casing may have a slit-like or other opening formed in a portion thereof through which the developing liquid may be directly passed to the passage portion of photoelectric detector means.

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~3 l ln the f`i~ dcvic~, ther~5 is a heating plate5 having 2 surfaces curved to III~Ch the propertie5~s of transfer paycr when 3 heated n~ th~ COII~ Ur~tiOJI Or ~al er tran~port ~a9 5age, ~nd 4 plate-like heater is uniformly brought into intimate contact with the heating plat~ to improve the heat transfer efficiency 6 and to prevent breakage of nichrome wire and increa-~se it~
7 durability, The heatillg plate may be a thin plate which will 8 lead to the provision Or a fixing device capable of attaining ~ .-9 quick temperature rise.
Further, the passage surface of the fixing device may 11 be divided so as to prevent jamming of copy paper within the 12 machine and also to permit removal of copy paper whenever it is 13 jammed.
14 In the copy paper feeder bed, separator pawls~ side -plates, intermediate plates and springs are all movable together 16 to provide a stable paper feeding force. :~
17 Also, in order to eliminate the necessity of directly . .
lô confirming the sizes of copy mediums carried on the paper feeder l9 bed by manually opening the lid such as outer plate or the like, lamps or like means are provided outside the machine to 21 enable detection and indication of the sizes.
22 In the buffer and stop device for original carriage, 23 the kinetic energy of the original carriage may be converted 24 into a potential energy of spring to decellerate and stop the carriage, thus alleviating the shock sufficiently. The 26 construction therefor may be relatively simply realized by the . ~.
27 use of energy absorbing springs and a one-way clutch mechanism, 28 which leads to a high reliability and lower cost, For the 29 movement of the original carriage in the opposite direction~
3 the energy accumulated in the springs may assist the carriage in - 16 _ 10~
attaining a quick start and this means an effective utilization of energy.
In the photosensitive drum supporting device, a support member for supporting the fixed end of a cantilever which sup-ports the photosensitive drum is coupled to a pair of Qide-plate frames adjacent the cantilever.
The above and other objects and features of the present invention will be more fully apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF T~E DRAWINGS
Figure 1 is a perspective view of a copying apparatus according to the prior art.
Figure 2 is a longitudinal cross-section of the Figure 1 apparatus.
Figure 3 is a perspective view showing an embodiment of the copying apparatus according to the present invention. ~ -Figure 4 is a longitudinal cross-section of the Figure -3 apparatus.
Figure 5 and Figure 6, which follows Figure 1, illustrate the change-over mechanism for optical means.
Figures 7, 8, 9 and 10 are schematic cross-sections of second, third, fourth and fifth embodiments of the present invention.
Figure 11 is a cross-sectional view showing a developing device and photosensitive drum according to the prior art.
Figure 12 is a transverse cross-section of the developing device shown in Figure 11.

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` 1()f~4'~4~t Figure 13 is a cross-sectiona view illustrating the flow of developing liquid in an embodiment of the developing device.
Figure 14 is a transverse cross-section of the Figure 13 device.
Figure 15 is a front view of an embodiment of the lift mechanism and slide portions of the developing device.
Figure 16 is a cross-section taken along line B-B of Figure 15.
Figure 17 is a cross-section taken along line C-C of Figure 15.
Figure 18 is a view taken from D in Figure 15 (or from ,,the rear side plate).
- Figure 19 is a front view of the developing device with .~ .
the developing eléctrode portion thereof withdrawn.
Figure 20, which follows Figure 16, is a perspective -~
view of a filter member. ~ ~
Figure 21 shows another embodiment of the developing --device.
Figure 22, which follows Figure 17, illustrates the -`:
construction of the connector portion in the embodiment of ~, Figure 21. `
Figure 23 shows still another embodiment of the - ~
.: ' developing device. -~; Figure 24 is a longitudinal cross-section of the den- , ,j .
'~t sity detector device according to the prior art.
Figure 25 is a cross-section taken along line A-A of Figure 24.
Figure 26 illustrates the construction of an embodi-I, ment of the density detector device.
Figure 27 i8 a cross-section of the Figure 26 embodi-ment taken along the impeller and the slit-iike opening.
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10~4;~49 Figure 28 is a cross-section of the photoelectric detector portion in the Figure 26 embodiment and showing such detector portion and the slit portion.
Figure 29 is a cross-sectional view of the drying-fixing device.
Figure 30, which follows Figure 28, is a cross-sectional view of a modification thereof.
Figure 31 is a longitudinal cross-section of the heating plate type drying-fixing device according to the prior art.
Figure 32 is a schematic, transverse section of the ; conveyor portion adjacent the drying-fixing device.
Figure 33 is an enlarged, longitudinal section of the essential portion of Figure 32.
Figure 34 is a longitudinal section of the device for opening the passage.
Figure 35 is a front view thereof.
Figure 36 is a longitudinal section showing the passage ~, .
~` in open position.
Figure 37 is a front view showing the passage in open position but with the front plate frame removed.
Figure 38 is a cross-sectional view of an example of the copy paper feeder bed.
, Figure 39 is a plan view corresponding to Figure 38.
Figure 40 is a perspective view of an embodiment of the paper feeder bed.
Figure 41, which follows Figure 3~, illustrates the movement of a side plate in the prior art feeder bed.
Figure 42 illustrates the movement of a side plate in the embodiment of the paper feeder bed.

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Figure 43 is a circuit diagram of detector switches and indicator lamps.
Figure 44 is a perspective view of a portion of the original carriage to which the buffer and stop device is applied.
Figure 45 is a longitudinal cross-section of the buffer and stop device.
Figure 46 and 47 are front view illustrating the manner in which the buffer and stop device operates.
Figure 48 is a front view of a modification of the buffer and stop device.
Figures 49 and 51 illustrate the construction according to the prior art.
Figure 50 is a diagram of the movement in the construc-tion of Figure 49.
Figure 52 is a transverse cross-section of the photo- ~ -, sensitive drum supported in an electrophotographic copying apparatus in a cantilever fashion according to the invention.
Figure 53 is a fragmentary front view corresponding to Figure 52.
Figure 54, which follows Figure 52, is a perspective view of the essential portion of Figure 52.
Figure 55 is a perspective view of another embodiment - of the supporting device.

Figure 1 is a perspective view of a copying apparatus according to the prior art, and Figure 2 is a longitudinal section thereof. On top of an apparatus housing, a movable original carriage 1 is mounted for reciprocal movement under guidance of rails 2 and 3 on the apparatus housing. A sheet .- - : -.
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1 origi~ l tr~l~s~rt l~r~ c~ pri~in~ transport roll~ 5, 6, 7 2 an,d 8 i~ constructed ~ ~ unit on the forward end (the left ~nd 3 as vicwed in l~igur~ ~) of th(~ nlovoblc original carriage.
4 Within the apparatu~ housing, illulllinating lamp~ 9 an~ 10 are provided to illun~inate an original fro~l thcrebelow. The image 6 of the original may be dirocted via a mirror ]4 and an in-mirro 7 lens 11 and focused on an exposure portion 12 Or a photosensitiv~
8 drum 13, as indicated by a dot-and-dash line in Figure 2.
9 Figure 2 shows the apparatus when it is used to produce copies I -of a sheet original. The ~heet original may be inserted along 11 an insertion guide plate ~æa~d toward the transport rolls 5, 12 6 and passed through an illuminating portion 15 and finally 13 discharged out of the apparatus by the transport rolls 7, 8.
14 Under such conditions, the movable original carriage is immovably fixed on the apparatus housing with the electrical 16 system of the carriage being coupled to the apparatus body by means of connector. '' 18 For the production of copies of a book or other thick 19 original, a change-over knob 18 (~igure 1) may be moved 20- leftwardly to unlock a lock mechanism for the movable original 21 carriage to thereby permit the carriage to move from a position i 22 22 to a position 21 in ~igure 2. Such movement releases the 23 connector between the original carriage and the apparatus body.
24 When the sheet original insertion plate 16 is pivotally moved to overlie the sheet original transport portion (as indicated 26 by 17 in Figure 2), the apparatus may now be used in t~e same 27 manner as the ordinary thiok original copying machine, namely?
28 by gripping a handle 20 to open an original keep oover 19, 29 placing an original on a glass plat~ 23 and depressing a copy 3 button 24 to automatically reciprocate the original carriage ,- , -~ ;

1 ~`or co~yil~g ol~era~ion. ~ latent imaao formed on t}
2 photo~ensitive drwlllnay be subjccted to various processes such 3 as dcvclop~ nt and iln~ge tran~fcr to t~lereby providc a vi~ibl~
4 inlagc on copy p~l~er. I
Figure 3 is a perspective view of a copying apparatu~
6 according to the present invcntion, which includes an apparatu~
7 housing 25, a sheet original transport portion 26, and an 8 original carriage Z7 for carrying thereon a thick original 9 (hereinafter referred to as "book original") and normally covered with an original keep cover 28. There are further 11 provided original carriage guide rails 29~ 30 and paper feeder 12 beds 31,32 for carrying thereon sheets of transfer paper P, the upper and lower beds being capable of containing different si~e~
14 of transfer paper. The present apparatus further includes auxiliary trays 34,35, an operating portion 36, a main switch 16 37, a group of indicator lamps 38-40, a selector Awitch 41 for 17 selecting the upper one of the two paper feeder beds, a selector 18 switch 42 for selecting the lower one of the two paper feeder 19 beds, a change-over lever 43 for effecting the change-over between a sheet original and a book original, a knob 44 for 21 selecting the number of copies to be continuously produced, a -22 copy button 45, an emergency stop button 46 useful during 23 continuous copying of book original~ and a throttle dial 47 for 24 adjusting the copying speed.
Referring to Figure 4, operation of such oopying 26 apparatus wili now be described with respect to the copying 27 of sheet original. As a sheet original is inserted from the "?
28 left between rolls 49 and 50 of the sheet transport portion 26 29 which are rotating in synchronism with a drum 48~ the sheet 3 original is transported rightwardly. When the leading edge of ..

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~::
thc shc~t ori~inal i~ d~tccte~i by a lamp 51 and light-sensing elcm~nt 52, th~ roll~ 49 an~ 50 are t~mporarily sto~ped and 3 accordini~ly the ~he~t origillal is also stopped. Next, whon th~
photosensitive drum 48 ~las reached a predetermined position, a start signal ~or the original is produced to cause the roll~ 49 6 and 50 to be again rotated to transport the original now downwardly in svnchronism wit~l the photosensitive drurn 48~ 90 ; 8 that the original is discharged through rolls 56,57 onto a tray 9 33 outside the apparatus housing. During that time, the original is illuminated by two lamps 55 in an illuminating portion 53 .... ¦
11 from the right-hand side as it passes the left side of a glasS
i 12 plate 54. At that time, as will further be described, a single s 13 mirror 58 is in its up position as indicated by dots-and-da-4hl 14 line, so that the image of the original is passed through a .~
lens 63 and via mirrors 61,62 and focused on the photosensitive 16 drum 48 in an exposure portion 64.
l 17 The photosensitive drum 48 comprises a `. 18 photosensitive layer covered with a transparent insulating ' 19 layer, and is normally rotating in clockwise direction as shown in Figure 4. The photosen~itive drum 48 i9 first positively ~ 21 charged by a primary charger 66 supplied with a positive high "~` 22 voltage from a high voltage source 65. When the photosensitive 23 drum reaches the exposure portion 64, it is slit-exposed to the 24 image from the.illuminating portion 53 and ~imultaneously I ~t 3~ . therewith, it is subjected to AC discharge ~rom an AC
':~ 26 discharger 67 supplied with a high alternating ourrent ~rom the 27 high voltage source 65. Subsequently~ the photosensitive drum 28 i8 subjected to an overall exposure by a lamp 68~ thereby !~ 29 forming an electrostatic latent image on the surface Or the . 30 photosensitive drum, whereby the drum enters a developing .' . ,' .

--', ' . . . _ . . _ .

o 1~

1 d~vic~ 69. 1`h~ dcv~lopi~ cvic~ 69 comprixe~ a containcr 71 2 for devclopill~ liqui~ 70, a pwnp 72 for agitating an~ raising 3 the devclopin~ liqui~, and a dcveloping elcctrode 73, which ix 4 adapted to be urged tow~rd the photosensitive drum 48 by a linkage 74 with a ~lig~lt clearance olaintained with r~spoct to 6 the drum 48. The electrostatic latent image formed on the 7 photosen~itive drwll 48 i8 developed into a v~sible image by the 8 toner in the devcloping liquid 70 raised over the developing 9 electrode 73 by the pump 72. Next, the photosensitive drum 48 is negatively charged by a post-charger 75 supplied with a 11 negative high voltage from the high voltage source 65, whereby 12 any excess developing liquid on the drum 48 may be squee~ed out 13 without disturbing the formed image. Subsequently, a sheet of 14 transfer paper P delivered from the paper feeding portion is brought into intimate contact with the photosensitive drum 4 16 and at a transfer charger 76, the image on the drum 48 is 17 transferred onto the transfer paper P ~ith the aid of charging 18 by a positive high voltage from the high voltage source 65.
19 After the image transfer~ the transfer paper P is separated ~`
from the photosensitive drum by a separator belt 77 and 21 directed to a drying-fixing portion 78. The photosensitive drum 22 48 is wiped by the edge portion 80 of a blade cleaner 79 urged 23 thereagainst to renove any residual toner and developing liquid, 24 whereafter another cycle of operation is repeated. The developing liquid so removed by the blade cleaner 79 is directed 26 through grooves formed on the photosensitive drum 48 at the 27 opposite end portions thereof and i~ reu~able ~or development.
28 On the other hand, sheets of transfer paper P are 29 contained in the paper feeder beds .31 and 32 which are mounted on the lower left feeder portion Or the apparatus body for ç~
10~4;~49 1 retractio~l to t~ ?l`t ( in Fi~ure ~) by mean~ Or rails. Two of 2 SUCIl p~pcr re~dcr ~d~ ay be providcd in accorda~lce with 3 difrer~nt i~c~ ~r tr~ fcr papcr and eithor Or them fllay ~e 4 ~elccted by dcprossion of selector button 41 or 42. Stocks of transfer paper ~ are carried on intermediate plates 81 and 82 within the fe~der bed~ 31 and 32, respectively, and these intermediate platc~ 81 and 82 are normally biased upwardly by 8 springs 83 and 84, re~pectivcly, so that the stock~ Or tran~for 9 paper P are maintained urged against separator pawls 85 and 86 which are provided on the opposite sides of the paper feeder 11 beds at the forward end thereof. By suitably ~electing a sprin~
12 constant for the springs 83 and 84, the stocks of transfer paper 13 P may be urged against the separator pawls.85 and 86 with a 14 substantially constant force, independently of the quantity of the transfer paper P in the paper feeder beds 31 and 32.
16 When the photosensitive drum 48 reaches a 17 predeternlined position, a signal is produced to lower the 18 normally rotating paper feed roll 87 or 88 into pressure 19 contact with the uppermost sheet of transfer paper P in the upper feeder bed 31 or the lower feeder bed`32, and the roll 21 cooperates with the separator pawl 85 or 86 to separate the 22 uppermost sheet P and feed it from the feeder bed 31 or 32 23 toward the right as viewed in Figure 4. However~ register 24 rolls 89,90, disposed closely adjacent the feeder bed~, have been stopped immed.iately after the lowering Or the paper feed 26 roll 87,89, 90 that the sheet of transfer paper P fed from the.
27 feeder bed 31 or 32 will form a slack between guides 91 and 92 28 with the leading edge of the paper sheet P 9trikin~ the nip 29 between the register rolls 89 and 90. Immediately therea~ter, 3 the photosensitive drum 48 produces a paper feed start signal ~ 10~4'~49 1 wllicll rototo~ tlle l~e~i~ter rolLs ~9 and 90 to transport the 2 tr~nsfor p~por ~hcc t 1~ at a spced equal to the peripheral spced 3 Or tllc ~ t~e~ runll~. On tllc o~hcr hand~ ~hc l~al~or 4 feed roll 87 or ~8 i~ again lift~d away rrom the stock Ortransfer paper P a predetermined time after its lowering, 6 whereafter paper transport is effected by the register rolls 7 89,90 and subsequcllt paper transport means.
8 The transfer paper separator belt 77 i9 in the form 9 of a thin endless belt and extends over a separator roll 95 ; 10 closely spaced from the photosensitive drum, and around 11 deflector pulleys 96,98 and pulleys 97,99,100. A portion of the ..
12 belt which is between the pulley 100 and the separator roll 95 13 bears against the drum 48 over an area corresponding to one 14 side edge of the transfer paper, and a portion of the belt which is between the pulleys 97 and 99 is caused by the action of the 16 deflector pulleys 96,98 to follow a path deviated from the 17 path of movement of the transfer paper. The separator belt 70 18 iB driven by the separator roll 95 at a speed substantially 19 equal to that of the photosensitive drum 48. During the image transfer, when a sheet of transfer paper P is in intimate 21 contact with the photosensitive drwn 48, the separator belt 77 22 intervenes between one side edge of the transfer paper and the 23 surface of the photosensitive dru~n. As a result~ at a point 24 where the separator belt 77 is separated from the photosensitive drum 48 by the separator roll 95, the transfer paper P which ~ 26 has so far been in intimate contact with the drum has one side 1 27 ed~e thereof forced away from the photosensitive drum. Once 28 the side edge is so stripped from the drum surface~ the 29 transfer paper P is entirely separated from the surface of the 3 photosensitive drwn 48 with the aid of the self-supporting 1' , .

10~4;~4~ i 1 ~tr~n~tll ~1` the p~ r it~clf ~n~ t~ orce of the win~ drawn 2 from a blow~r through a duct 102 into an intake port 103, 3 wh~rcafter the transrcr paper ls transported to thc drying- i 4 fixing portion 78.
In the drying-~ixing portion 78, the transfor paper P
6 is heated by a hcating plate heater 104 as it is leftwardly 7 transported in contact with the heater, and alYo it i~ drled and fixed by the wind blowing through the duct 102.
. . 9 The air drawn into the intake port 103 is the air : 10 staying within the apparatus and the draw-in of such air also 11 results in cooling of the interior Or the apparatus. As the 12 drawn air passes through the intake port 103, it i9 somewhat 13 heated by the heating plate heater 104. Part o~ the air so 14 drawn in is discharged out of the apparatus, while the rest of the air is sent out through the duct 102 to provide the 16 drying-fixing efrect as described. The air.thus warmed is 17 finally discharged out of the apparatus by another blower (not :. -, 18 show.n) through an exhaust duct 105.
! 19 After having been dried and fixed, the transfer paper . P has any residual charge thereon removed by a discharger 106 i; 21 whereafter the transfer paper is directod through discharge 22 rolls 107 to a discharge port 108 for discharge onto a tray 23 34 or 35.
24 A lamp 109 and a light-sensing element 110, both ~; 25 disposed at the sheet original inlet port~ perform the function 26 which will be described below. In order to prevent deterioration 27 of-the photosensitive dr~n and othor parts~ the present cop~ing 28 apparatus i8 designed such that it stops its operation with it~
i~ 29 main switch remaining in ON position for ten and several seconds after completion of a copying operation. Nhen this occurs, the .~

. ~ - 27 -!~ ~ ~~~r~ r~

10~4'~49 1 ~ origi~ t.~ ctc~ted ~y t~lc l~lllp 10~ and 2 light-~ell~ing cl~rl~nt ~10, wllereupon the apparatu~ gain 3 operated to ycr~mit o col~ying op-~ration to occur.
4 Op~r~tion l`ol~ tl~e co~yill~ of book original will now be describcd with rcrcrence to l~igure 4. Since the mirror 58 6 is now in its lowere~ position a~ indicated by full lin~, the image of an original Ill~y bc projoctcd via mirror~ 59,58, lon~
63 and mirrors 61,62 OlltO the drum l~8. A book original to be 9 copied is placed on the original carriage glass 111 with one end of the original registered to one end 112 of the glass, and 11 then the book original is held down by the keep cover 28.
12 When the copy button 45 (Figure 3) is depressed, as in the case 13 of sheet original, an original start signal from the , , 14 photosensitive drum 48 moves the original carriage 27 léftwardly in Figure 4 in synchronism with the peripheral speed 16 of the photosensitive drum 48, so that the book original on the 17 carriage is illuminated by illuminating lamps 113 to effect Q
18 slit exposure. Upon completion of the exposure, the original 19 carriage 27 stops its leftward movement in response to a signal from the carriage 27 itself and in accordance with the size of-21 the original, and immediately reverts to movement in the 22 reverse or rightward direction. The speed of this reverse 23 stroke is higher than that of the forward stroke to thereby 24 increase the copying efficiency. As soon as the original carriage 27 returns to its initial position, the drive to the 1 26 original carriage is cut off and the carriage comes to a halt.
27 - When multiple copies of the same book original are 28 to be produced continuously, this ma~ readily be accomplished 29 by the use of a counter device 44 operatively associated with 3 the copy button 45. The counter device 44 holds the copy 31 button 45 effective until a predetermined number of copies ~ .

~ 4'~49 ha~i b~ n counl;c(l ul-~ Ihua ~JIablirl~ production Or Illultiple ~o~ic:,.
2 Thc othcr ol~crotions are similar to those in the ca~c 3 of sheet original.
Agairl in t~le casc of book orig nal, the up~aratu~
stops its operation in tcn and ~everal seconds after completion 6 of the copying, but in this case the copy button 45 also ~erve~
7 as a start switch and depression of this button will start the 8 apparatus to resume a copying operation.
Next, the change-over between the book original copying mode and the sheet original copying mode will be 11 described with reference to Figures 3 to 6. According to the 12 present invention, as described above, the movable mirror 58 13 is moved to selectively form two optical paths for sheet 14 .original and book original, and a mechanism therefor will be described hereinafter. Figures 3 to 6 show the book original 16 copying mode. In this mode, the image illuminated by the 17 illuminating lamps 113, namely, the image of the original on the 18 glass 111, is projected via mirrors 59,58, lens 63 and mirrors 19 61,62 onto the drum 48. When this occurs, the change-over lever 43 has been pivoted rightwardly (Figures 4 and 5).
21 The mirror 58 is held inside a mirror block 114 by 22 means of springs 119 (provided between the mirror block 114 and 23 the mirror 58, see Figure 6) and by means o~ metal fittings 120.
24 In such book original copying mode, the mirror 58 is urged against the positioning surface 12Z of another mirror block 121 26 by springs 119, thereby forming an accurate optical path for 27 book original. The metal fittings 120 and the mirror 58 are 28 then 9paced apart, but when the mirror 58 is ~umped up, the 29 mirror and the metal fittings may be in contact with each other 3 so that the mirror 58 may not be detached.

~ 49 1 Wh~n t~ cllun~c-over levcr is pivotc~ leftwardly, a 2 ~ ft 127 ~ ~4u.lr~ cr~ ection is rotatcd counter-cloc~wi~e 3 ~y u linl; 130 ~n~ v~r 131. T~lo s~lart 127 i~ rot~tably 4 journalled by m~ans o~ bcarings 128 and 129, The movement ur the shaft 127 is tr~n~lllitted to the mirror bloc~ 114 by lc~er~
6 123, 126 and by pin~ 117,116 eng~ged with slots 124,125 in tho 7 levers 123,126 and securad to tho mirror block 114. Since t}le mirror block 114 i~ pivotally ~upported by pin ~nd tlole 9 connections 118,115, it is pivoted clockwise. A switch 132 (Figure 5) detects the movement of the lever 126 and effects 11 the change-over of the electrical control system between the 12 book original copying mode and the sheet original copying mode.
13 Since the mirror 58 has thus been jumped up, the image being 14 illuminated by the lamps 55 (i.e. the image of a sheet original as it passes the left side of the glass 54) is projected via 16 the lens 63 and mirrors 61,62 onto the drum 48.
17 Figure 7 shows a second embodiment of the present 18 invention. This embodiment is substantially similar in 19 construction to the first embodiment, excepting the mirror construction. In the book original copying mode~ a movable 21 mirror 133 is in the position as indicated by full line so that 2Z the image from the movable original carriage 27 may be 23 projected upon the drum 48. When the mode is changed over to 24 the sheet original copying mode, the mirror jump9 Up to a position as indicated by dots-and-dash line 134 so that the 26 image of a sheet original passing below the glass 54 may be 27 pro~ected upon the drum 48.
28 ~igure 8 shows a third embodiment Or the present invention, which is substantially similar to the second 3o embodiment with the exception that a mirror 139 ia rotatable ~ 3 -.' 1 t~lI`Otlgh 90 t~ ~f~`cct tll~ c}la~ over bctwcell two opti~al pat}ls.
2 ~i6ure 9 Stlo~ a fourth cmbodime~t of the present 3 invelltio~ 21i~ elu~odinl~ t, a Illirror 140 is hori~ontally 4 movable to efrect the charlge-over between two optical paths.
~?igure 10 illustrates a fifth embodiment o~ thc 6 present invention. In t]liS elllbodiment, the original carriag~
7 is stationary and an ori~rinal placed on the glas~ 111 of the 8 original carriagc may bc scanned by mirrors. A mirror 141 is 9 reciprocally movable at a velocity V and a mirror 142 at a velocity 2. The latter mirror 142 is rotatable to effect thc 11 change-over between two optical paths.
12 The present invention has so far been described with 13 respect to its application to the copying apparatus of the 14 image transfer type, whereas the invention is not restricted to such type but is applicable to any copying machine, even o~
16 the direct type which ùses sensitive paper~ if it includes 17 mirrors and lenses.
18 Developing Device 19 Referring to ~igures 11 and 12, a photosensitive drum 201 comprises a photosensitive layer covered with a transparent ~, 21 insulating layer and is rotatable in clockwise direction. The 22 photosensitive drum 201 is positively charged by a primary 23 charger 202 and, where the drum reaches an exposure portion 204, 24 it is slit-exposed to the image of an original and simultaneously therewith, it is subjected to AC discharge or secondary charge 26 of the opposite polarity to that of the primary charge, by a 27 discharger 203. Subsequently, the drum is sub~ected to an 28 overall exposure by a lamp 205 to thereby form an electrostatic 29 latent image on the surface of the photosensitive drum, 3 whereafter the drum enters a developing device 206. The 1o6~4249 1 deVe10~ ,r ~ V1~ oG ~m~ S a contairlcr 208 for tJovclopirl,~
2 liquid 207, a pump 209 for agitating and rai~ine thc developirlg 3 liquid 207, and a developing electro~^ 210, which is adaptcd to 4 be urged toward thc ~hotos~nsitive drum 201 by spring~ 211 with a slight clearance maintained with respect to the drum Z01.
6 The electrostatic latent image formed on the photosensitive 7 drum 201 is developed into a visible image by the toner in the 8 developing liquid raised over the devcloping electrode 210 by 9 the pump 209.
Next, the photosensitive drum 201 i9 charged by a 11 post-charger 212, whereby any excess developing liquid on the 12 drum 201 may be squeezed out without disturbing the formed image., 13 Subsequently, a sheet of transfer paper P delivered from a 14 paper feeding portion is brought into intimate contact with the photosensitive drum 201 and, being charged by a transfer 16 charger 213, the image on the photosensitive drum 201 is 17 transferred onto the transfer paper P, whereafter the transrer 18 paper P i6 directed to a drying-fixing portion by a separator ' -;.19 belt 214. The photosensitive drum 201 is wiped by a blade ~ ~ -cleaner 215 urged thereagainst to remove any residual toner 21 and developing liquid, whereafter another cycle of operation is 22 repeated.
23 Plate-like angles 217 and 218 are attached to the 24 bottom 216 of the copying apparatus ànd engaged with pro~ections 219 and 220 of the developing device 206 and 26 slidable in the direction of arrow in ~igure 12.
27 To withdraw the developing unit A from the copying 28 apparatus body, the developing electrode 210 is lowered again~t 29 the force of the springs 210 to provide a sufficient spacing 3 between the photosensitive drum 201 and the deYeloping electrodo ,, . - 32 - ~ .
.
~,' 106~Z49 210 t~ p~rlllit wi~ r~w.l ol` tll~ devcloping unit, whor~by thii 2 dcvclo~)in~ unit A c~n bc ~ilidden by the cooperation betwoen t~lc 3 plate-likc angle~ 217,21~ ~nd th~ proicctions 219,220 ror 4 removal rroM t~l~ apparatus body. -Circul~tion Or tllc developing liquid between tho developing electrode and the devcloper container will rirst be 7 described.
8 In l~igure 13, the ~evcloper container i9 designated 9 by 221 and stores therein developing liquid 222, which may be filtrated through a filter 223. A motor 224 is provided with 11 an impeller 225 for supplying the developing liquid 222 to a 12 developing electrode portion A. A pump casing 226 has an 13 outlet port 227 formed in a portion thereof, which~outlet port 14 is connected to a pipe 228, which has the other end relea~ably connected to a connector 230 of a deyeloping electrode (which 3 16 will later be described) located in the developing electrode 17 portion A. The photosensitive drum, designated by 231, has 18 thereon a photosensitive medium comprising a photosensitive 19 layer covered with a transparent insulating layer, and is supported by a shaft 232. The photosensitive drum i9 surrounded 21 by various means and devices for the formation of electrostatic 22 latent image (which are similar to those shown in Figure 11).
23 Disposed below the photosensitive drum 231 i9 an arcuate 24 developing electrode 229 which i8 capable of applying a developing bias voltage to the surface of the photosensitive 26 drum with a spacing 1 with respect to the latter. A dish 233 27 is provided for receiving the developing liquid supplied to the 28 developing electrode 229 to develop the electrostatio latent 29 image, and has an outlet 234 formed-in the bottom thereof at the forward end. Connected to the outlet 234 is a drain pipe 235~
,'' . . ' , ,.j, ~ 33 ~
IL

1~)64Z49 th~ oth~r ~nd Or wllich i~ removably connected to a conncctor 2 236 of t~lc developcr container 221. The dish 222, as ~hown in F`igures 13 and 14, i3i formed with a sloped Yurfaco for helping the develo~in~ liquid to form a stream and for preventing the toner from precipitating on the wall of the 6 dish. Spacer roll~ 237 and 238 are disposed in contact with 7 the photosensitive drum 231 and maintain a clearanc~ 1 between 8 the photosensitive drum and the developing electrode 229.
9 A fog removing roller 239 is provided to remove the fog from the formed image. The stream of the developing liquid will 11 now be described.
~ 12 When the copying apparatus is not in operation, the;5~ 13 motor 224 is stopped and the liquid in the developer container '3! 14 221 is at the level Ll. Thus, the filter 223 is immersed inthe developing liquid to prevent the clogging of the filter 16 which would otherwise result from solidification of toner.
17 Next, when the copying apparatus is operatcd, tho 18 motor 224 revolves in the direction of arrow, and the I
~,~ 19 developing liquid is drawn into the casing 226 by the impeller ~ 20 225 and passea through the pipe 228 in*o the developing t 21 electrode 229 to strike against a flow velocity reducing plate 22 242~ by which the developing liquid has its flow velocity 23 reduced and slowly passes through an opening 243 formed in the 24 developing electrode 229 along the entire length thereof, so that the liquid fills the clearance 1 between the drum 231 and 26 the electrode 239 to thereby develop the electrostatic latent 27 image into a visible image due to depo3~1tlon of toner particle~
28 on the latent image.
29 The developing liquid ~lowing out at the left 9ide 3 244 of the fog removing roller 239 in ~igure 13 (the front and ~ . I
~ ~ 34 - I
~. ,~

-:o ~

1 rc~r cnd fuccs '45 .~ 6 of t~le devclo~ing electrodo 22'J aj 2 viewcd in ~i~ul~e 14) i~ receivod in the disll 233 an~ rlOws ~OW-I :
3 along t~le sl~ped ~ur~cc thercol to thc outlet 235, f`rom whiet 4 the developing liqui~ falls through the drain pipe 235 whilc being ~iVOII u ~uf`~ieiell~ ener~y by tlle hoad H. AY part Or tt developing liquid in the developer containcr 221 rcaches tho 7 developing electrodc 229, the quantity of the developing liquid 8 in the container "~ ~radually decreases while part Or the developing liquid begins to collect into the container through the drain pipe 224, thereby providing a constant liquid level 11 at which the decrease and increase are balanced within the 12 developer container, Such constant level is indicated by L2.
13 The filter 223 now exposes itself entirely out of the liquid, 14 but the drops of developing liquid given a sufficient energy lg by the head H strike the exposed filter 223 to crush the toner 16 on the filter and al40 prevent masses of toner or dust from 17 sticking to the filter so as to ensure the filter to filtrate 18 the developing liquid sufficiently. The developing liquid 19 filtrated through the filter 223 forms a rapid flow in the developer container 221 and flows into the pumping portion.
21 Thus~ precipitation of toner can be prevented and surficient 22 agitation of the liquid can be ensured by the rapid flow.
23 It will thus be seen that, by constructing the 24 developçr container 221 and the developing electrode separately from each other and connecting them together by pipes, the 26 volume of the developing liquid in the container can be selected ~ .
27 as desired, in accordance with the intended purpose.
28 Description will now be made of a mechanism for 29 withdrawing the developer container and developing electrode portion from the copying apparatus body. In Figure 13 and 14, ~ 35 -- - ~ ~

1()~ 49 1 the anglc ~ 0 i~ ~ccure~ to t~l~ bottom ~url~ace Or the devel~pi~
cont~iner ~21 ~n~ en~agcd with an~les 241 and 247 ~ecured to 3 the apparatus body. The angle 2/l~ is slidablo in thc dilection 4 as indicatcd by arrow in Figure 14. The developing containor 221 is secured to the ap~ar~tu~ body by screws 248 and, by 6 pulling it in the direction of arrow or rightwardly, the angle~
240 and 241,247 may be disenga6cd to permit removal Or the 8 container from thc apparatus body.
Referring to ~igures 15 and 17, description will now be made of the mechanism whereby a spacer roller 237 may be i 11 urged against the photosensitive drum 231 to maintain a 12 clearance 1 between the drum and the developing electrode 229.
13 Slide shaft mount plates 249 and 250 are ~ecured to the bottom - 14 Or the dish 233 and slide shafts 251 and 252 are secured to the mount plates. Likewise, slide shafts 253 and 254 are secured 16 to a slide base plate 255. The slide shafts 251 and 252 have 17 sleeves 256 and 257 slidably ritted thereon and have sleeves 18 258 and 259 fixed thereto. Likewise, slide shafts 253 and 254 19 have sleeves 260 and 261 slidably fitted thereon and have sleeves 262 and 263 fixed thereto. Links 266, 267, 268 and 21 269 of equal length intersect one another at the center and are 22 caulked together for rotation about an axis. These links have ;
~ ~ 23 their opposite ends pivotably secured to the sleeves 258~ 259~ ¦

1~ ~24 256, 257 and the sleeves 250, 261, 262, 263, respectively.
3~: 25 Tension springs 270 and 271 extend between and are secured to 26 the sleeveD 261, 263 and 260, 262 to normally bias the links to 27 their open position. Levers 272 and 273 are rotatably mounted 28 on the slide base plate 255 and each have one end fitted to ! 29 ~hafts (not shown) secured to the underside of the sleeves ' 3 260,261 and the other end fitted to a connector lever 27~ which ~,,, s - 36 --, Q
~0~4Z49 1 conn~ct~ tll~ lever~ 272 all~ 273 together. Likewise, a lever 2 275 is rotatably Inounted on the slide plate 255 and has onc en~
3 fitt~ to the conrlc~t~r lov~r z74 ~nd the other end ~ngaged 4 with a stop provided on the bent portion of the slide base plate 255.
. ~ecause of` the above-describcd construction, the : 7 sleeves 260 and 261 slidably ritted on the slide shafts 253 8 and 254 are rightwardly moved by the forces of the tension 9 springs 270 and 271. With this, the sleeves 256 and 257 slidabiy fitted on the,slide shafts 251 and 252 are also 11 rightwardly moved by the links 266, 267, 268, 269 while rising ?~
~ 12 in parallel to the slide shafts 253, 254. This also causes the '7 13 developing electrode portion A secured to the slide shaft mount 14 plate 250 to rise together until it is stopped with the spacer roller 237 urged against the photosensitive drum 231. This 16 position is shown in Figure 16.
17 To lower the developing electrode portion A, the ~ 18 lever 275 may be rotated counter-clockwise (the direction of ., 19 arrow) to thereby cause the connector lever engaged with the lever 275 to move toward this side in Figure 15 ( the direction 21 of arrow). This in turn causes the levers 272 and 273 engaged -22 with the connector lever 274 to be rotated clockwise (the 3 direction of arrow), which also causes the sleeves 261 and 262 24 slidably fitted on the slide shafts 253 and 254 to slide leftwardly (the direction of arrow) against the-forces of the ; 26 springs 270 and 271. Thereupon, the sleeves 256 and 257 :3 .
s 27 slidably fitted on the slide shafts 251 and 252 are also 28 leftwardly moved by the links 266, 267, 268, 269 while lowerin~
in parallel to the slide shafts 253 and 254. When the photosensitive drum 231 is withdrawn along the shaft 232, the :

.' :~ ~

~o64Z49 1 d~velo~)ir~ ctr~ porti~n A is lowcrcd until thcre is 2 provided ~ ~ufl`ici~llt clear~nce 1' to keep the spacer roller 3 237~ tllc l`og I`~'lllOVillg roller Z~ ~nd the like oI~ the drum, 4 whercupon tlle ~eY~lopin~ ~lectrode portion A ix ~topped at it~
lowercd po~ition, a~ain~t tl~o forccs of the springB 270 ~d 6 271, by the ~top provide~ on the bent portiorl Or thc ~lide 7 base plate 255.
In l`igures 16 and 18, a rear ~ide plate 276 has 9 secured thereto a reinforcing casting 277 which provides reinforcement of both the rear side plate 276 and the 11 photosensitive drum shaft 232. Further, reinforcing struts 278 12 and 279 also for reinforcement of the rear side plate 276 and 13 the drum shaft 232 are secured to support castings 281 and 282 14 which have the opposite ends secured to the reinforcing casting 277 and a front side plate 280, respectively.
16 Slide castings 283 and 284 are slidably fitted to the 17 reinforcing struts 278 and 289 and have a slide base plate 28$
18 attached thereto. Two angles 286 and 287 are spot-welded to 19 the upper surface of the slide base plate 285 and slidably engaged with the bent portions 288 and 289 of the slide base 21 plate 285.
22 Two pairs of rollers 290,29~ and 292,293 are 23 rotatably mounted on the reinforcing strut castings 281 and 282 24 secured to the front side plate 280~ and the slide base plate 285 is held between the rollers 291 and 293 and between the rollorx 26 290 and 292. The slide base plate 255 is provided with a 27 handle 294, and stops 295 and 296 are secured to the reinforcing 28 struts 278 and 279.
29 In the above described construction, to withdraw tho 3 - developing electrode portion A out of the apparatus body, as ~o~4~49 1 i-Jie~crib~ riviously, tl~ vclopillg o~inctrod~o portion A i~
2 first lowered, an~l t}lcrl wit}ldrawn by gripping thc handle 29li~,3 whercby the sli~lie b~ o plate 255 slid~s in the engrrlgi-ml~n~
4 portions bi3tweoll th~ bent ~urtiono 288,289 i~nd thc an,~le~
286,287 on thc slidc biiso plate 285 to come out toward thi-i 6 side in Figure 15, until it is stopped on its way by a stop 7 (not shown), whereupon the slide base plate 285 now come~i out 8 with the slido castings 283 i~d 284 slidably fitted to thc 9 reinforcing struts 278 and 279 (see Figure 19). When the developin, electrode portion A has come completely out Or the 11 front side plate 280, the end faces of the slide castings 283 12 and 284 strike the stops 295 and 296 on the reinforcing struts 13 278 and 279, thus coming to a halt.
14 It is to be noted that withdrawal Or the developing electrode portion A requires the steps of loosening and 16 removing the connector 236 of the drain pipe 235, loosening and , 17 removing the connector 230 of the pipe 228 in the course Or 18 withdrawal, and breaking the connection between the developer 19 container 221 and the developing electrode portion A. As described above, the developer-container and the developing 21 electrode portion are constructed separately from each other and ; -~
22 connected together by pipes so as to permit circulation Or 23 developing liquid, and a plate provided with a lift mechanism 24 which is capable of maintaining a constant clearance between the developing electrode portion and the photo~ensitive drum i~ -26 slidably placed on a casting slidably fitted to two reinforcing ~ -27 struts which provide reinforcement of both the copying apparatu~ .
28 body and the photosensitive drum shart 1 90 that wben the 29 developing electrode portion is to be withdrawn from the apparatus body the electrode portion may first be lowered away ~ 39 -~ . ' .

" @, ~Q64Z49 1 l`rOIII t~l~! ph~to~ell~itiv~ um i~url`ac~ by tho lilt moctl~ nl, 2 wllere~rt~r the dcvclo~ electro~c l~ortion may bo pulle~
3 outw~rdly, ~ rcby tho ~ t~ c~rrying thercon t~le ~eveloj~irlg electrode portion and the lift mech~nism is slidingly withdrawn until stopped by stops providcd on tho plnte secured to the 6 casting slidably ~itt~d t`o the reinf`orcing struts, whereupon 7 that plate may now slidc alon~ thc reinrorcing struts and tho developing electrode portion may stop at a position project~d 9 outwardly of the apparatus body.
In such position, the developing device permits its 11 servicing, inspection, repairs, etc, to be done with great ease 12 and high efficiency as well as quickly and accurately, thus 13 facilitating to maintain the performance of the apparatus. ~ ?
14 Also~ the separate connections of the developer ! : -container and the developing electrode portion contribute to the 16 ease with which the developing device is handled, serviced, 17 inspected, repaired or otherwise treated.
18 In the developing device constructed as described above, when the apparatus is not in operation or when the motor 224 is not rotating, the developing liquid 222 in the container 21 221 maintain~ the liquid level Ll. As a result, tho filtor 223 22 is fully immersed in the developing liquid 222 so that the 23 filter 223 is prevented from clogging which would otherwise 24 result from solidification and deposition of toner on the filtor due to evaporation of the developing liquid. Next, when the 26 apparatus is operated~ the motor 224 revolves in the direction 27 of-arrow so that the developing liquid is drawn into the casin~
28 226 by the impeller 225 and passed through the outlet 227 and 29 the conduit 228 into the developing electrode 229, and impinges on the proJected end 242, wher~eby the flow velocity ., ~' 1 Or thc dcvelopi~lg li-lui~ i~ roduc~d, Then, t~le liquid slowly 2 dischar~cs through thc opcning 243 extending lengthwi~e Or t~lo 3 photosensiti~e drum 231 an~ ril~s the slight clearanc~ 1 between the drum 231 and the developing electrode 229 to devclop the eloctrostatic latcnt iniage on the photosensitivc 6 drw~ 231. The developing liquid o~rflown from tho d~veloping 7 electrode 229 is received in the dish 233 and flows down along 8 the sloped surface of thc dish to concentrate in the opening 9 234, from which the liquid falls through the drain pipe 235 while being given an energy by the head H, and strikes against I -11 the filter member ~23 in the developer container 221. With tho 12 start of the apparatus, the developing liquid 222 begins to 13 circulate through various parts so that the liquid level in the 14 developer container 221 is gradually decreased to a predetermined level L2. In such state, the filter member 223 16 emerges fully out of the liquid and struck by the falling 17 developing liquid given a sufficient energy by the head H.
18 Thus, any solidified toner masses are again dispersed and the 19 toner masses or dust may be prevented from sticking to the filter member, which can thus perform its filtrating function 21 sufficiently. The developing liquid 222 passed through the 22 filter member forms a rapid flow in the developer container 221 23 and flows into a pumping portion to prevent precipitation of 24 toner, while the rapid flow is again useful to provide a sufficient agltating effect. It will be noted that the 26 developing liquid which falls onto the filter member 223 27 strikes against the sloped surface portion 297 of the filter 28 member 223 to force dust or other impurities from such sloped ~*
29 surface portion 297 to the flat surface portion 298 for accumulation thereon. The filter member may be removably _ 41 ~

! .
. _ 1()64Z49 1 tll~uJlt~d to f`LIci~ t~ its r~ c~metlt or cleaning.
2 In otll~r word~, thc construction is such that a 3 member for disp~ ton~r III~S~CS i! interposed between thc 4 devoloping portion and the li4uid container Or the liquid d~vclopin~ dcvicc ~o ~ to pcrolit thc devclopin~ liquid to 6 circulat~ through ~aid membcr. This enables any toner musse~
created in ~he dev~loping liquid to be re-dispersed by said 8 member to providc sufficiently filtratod and mixed developing liquid. In the illustrated embodiment of the apparatus, if tho apparatus remains inoperative for a long time, the developing 11 liquid on the developing electrode 229 and the dish 233 will 12 evaporate and the toner in the liquid will solidify to form 13 relatively large masses. When the apparatus resumes its 14 operation, these relatively large masses o~ toner will be washed away by and mixed with the developing liquid, but the toner 16 masses will pass through the drain pipe 235 to strike against 17 the dispersing member and be finely crushed thereby, with a 18 result that no large toner mass will be contalned in the liquid 19 supplied to the developing portion A. Further, any large toner masses captured by said member will be finely crushed due to the 21 continuous fall of the developing liquid. Thus, according to ~
22 the present invention, any toner masses may be finely crushed 23 and redispersed and the filtration Or the developing liquid may 24 be fully accomplished, thereby eliminating such disadvantages as unevenness of the resultant copy images and injuries imparted 26 to the photosensitive medium.
27 Although the above embodimenbs have been described 28 with respect to an electrophotographic copying apparatus using 29 a photosensitive medium, it will be obvious that the invention 3 is also applicable to copying machine~ of the fax type which . ~'.

~ - 42 -~064Z49 u~o sell~itivc ~L~pcr.
2 Rererrirl~ now to l`iguro 21, the photosen~itivc dr~ll 3 ~31 is surr~ led ~y v~riou~ mcan~ for forming an elcctrost~til:
latent i~age corre~ponding to thc image of an original and mean~ (not shown) for tran~ferring the image, developed by 6 developin6 portion, to tronsror papor. The dovclopin~ ~ovice 7 for developing tlle clectrostatic latent imago into a visible image compri~c~ individu~lly constructed developin~ ~ortion A
9 and developer container portion B, which are connected togeth~r by a supply pipe 228 and collection pipe 299. The developing 11 liquid 222 in the container 221 forming the container portion~B
1 12 is drawn into the casing 226 by the impeller 225 rotated by thc ``i 13 motor 224, and is delivered to the developing portion A throu~h 14 the supply pipe 228. The developing liquid is then directed to the developing electrode 229 forming the developing portion A, 16 to thereby develop the electrostatic latent image on the ?i 17 photosensitive drum 231 into a visible image. The developing 'J 18 liquid 222, which has thus been used -for the development of the ¦~ 19 electrostatic latent imagc, is collected in the dish 233 and j-~ 20 falls into the container 221 through the collection pipe 299.
21 Further, the angles 241 and 247 secured to the copying 22 apparatus body 300 at the bottom Or the container 221 o~ the 23 developing liquid container portion B are engaged with thc 24 angle 240 secured to the bottom Or the container 221 and are capable Or moving the container 221 in the direction ~`~ 26 perpendicular to the plane of the drawing sheet. The developing 27 portion A i~ designed (not ~hown) such that the roller 230 i~
28 normally in contact with the outer poriphery o~ the -~ 29 photosensitive drum 231 to maintain a clearanae 1 between the drum 231 and the developing electrode 229 and that the outer ',-:
~ 43 ~
~f' ~
;.' '"

~.()64Z49 1 peripllely ~f thc ~hoto~cnsitive drum 231 and the rollcr 237 may 2 be brou~ht out of corlta~t with each other either by depressing 3 the ~eveloping portion A or by raisiJl~ th~ photos~njitiv- ~rw 4 231, to thereby pcrlDit removal of the deYeloping portion in the directi.on pcrpendicuLar to the pl.ane of the drawin~ ~hcet.
6 The developing portion A also includes a roll 239 effective to 7 prevent fogging Or the visuali~ed image on thc photosonsitivo 8 drum 231, and a cleaning member 301 for the roll 239.
9 Removable connectors 230 and 236 are provided on one end of the supply and collection pipes 228 and 299 each, and the 11 removability of these connectors 230 and 236 is utilized to 12 connect the pipes 228 and 299 in the manner as indicated by 13 dots-and-dash lines, so as to provide independent circulation 14 paths 302 and 303 for the developing portion A and the developer container portion ~, respectively.
16 An example of the construction Or the above-described 17 connector 230 will now be described in connection with ~igure 18 22. As shown, a connecting member 304 is fixedly secured to the developing electrode 229 as by screws or adhesive, and a connecting member 305 is also fixedly secured to the supply 21 pipe 228. The connecting member 305 has a coupling nut 307 1 :
22 engaged with a projection 306, which coupling nut 307 is 23 internally threaded for mesh engagement with the external 24 threads formed on the outer periphery of the connecting member 304, with a result that the supply pipe 228 is communicated 26 with the deveioping portion A. An anti-leakage rubber packing 27 308 is interposed between the two connecting members 304 and 28 305. Another connector portion 236 shown in ~lgure 21 is 29 similar in construction and si~e to.the connector 230 and so, 3o as indicated by the dotR-and-da~h lines in Figure 21~ the '.1 ~ 4 _ i~
1C~64Z49 1 collcction ~ f` thc d~vclol)ing portion A is conncctiblc 2 to the supply port ol` the portion A and the ~upply port 228 i~
3 conn~ctible to thc collection port of the devcloper containQr.
4 The~e pipe~, which thus provide connection between the doveloping portion and tlle devcloper container portion, ~re 6 designed to providc circulation paths in the individual 7 portions, whereby th~e pipes will neither interfere with the 8 removal of the developing portion A or the container portion }3 9 nor permit leakage of the developing liquid. Further, in the developer container portion B, the provision of the independent 11 circulation path leads to the possibility of the trial operation ' 12 of the container portion B.
13 ~igure 23 shows a ~imple embodiment of the present 14 invention. In this embodiment, as shown, the supply pipe 228 and the collection pipe 299 connecting the developing portion A
16 and the developer container portion B are each divided into two 17 parts, and these respective two parts are further connected 18 together by a connecting pipe 309 or 310. In such construction, 19 by rèmoving the connecting pipes 309 and 310 from the supply pipe 228 and the collection pipe 299, the supply pipe 228 21 connected to the developing portion A and the collection pipe 22 299 connected to the container portion ~ may be connected 23 together through a connecting pipe 309 (or 310) to provide an 24 independent circulation path in the developer container portion B. ~urther, the supply pipe 228 and the collection 26 pipe 229 connected to the developing portion A may be connected 27 through a connection pipe 310 (or 311) bo provide an independent 28 circulation path in the portion A. The embodl~ent Or ~igure 23 29 can also achieve the effect as described in connection with 3 the embodiment of Figure 21 and in addition, can provide the - 45 ~
~, ~1 ' 1(~64Z49 l circulation ~ tll~ nlor~ ~iml)ly ~n~ rel~Jil)~ than the cmbodin~ellt Figur~ 21. In l`ig~ure ~'3, the parts similar to tho~e in 3 Figure 21 are giVell ~ ilar r~ferenc~ nw~ral~.
4 According to this embodiment of tho prc-~cnt invention, as will be approciated, the moans for conr.ecting the developing 6 portion for developing the electrostatic latcnt image to th~
7 container portion for containing the developing liquid to be 8 supplied to the developing portion are connected 90 as to provide an independent circulation path in each of the two portions. With such construction, the developing portion or ll the developer containing portion may be removed from the 12 apparatus body without being interfered with by the pipes and 13 without the possibility of the developing liquid leaking from 14 the developing portion or the container portion. Furthermore, the pro~ision of independent circulation paths permits the 16 trial operation of the container portion to be effected.
17 It is to be noted that the supply pipe or the 18 collection pipe, when one end or a part thereof has been 19 removed to make the container portion and the developing portion independent from each other~ may be fixed by hook or 21 like means so as to prevent outward leakage of the developing 22 liquid. Although the above embodiment has been illustrated 23 with respect to a developing device in the electrophotographic 24 art using a photosénsitive medium, it will be apparent that the embodiment is applicable to other developing devices such 26 as mist developing device or diazo developing device.
27 Referring to Figure 24~ a small density detector 28 chamber 315 is defined in developing liquid 314 within a 29 developer container 313 and a passage 316 is formed of glass or like transparent material and extends vertically in the i. ' _ 46 - !
~, ~0~4Z49 1 chamber so that p.,rt ~r thc ~eveloping liquid to bo ~upplic~
2 to the devclol~in~ portion nlay be dircctcd from UIIS~10~1 pump 3 throu~h a conduil 319 intu thc passage 316. A light sour~e ~17 4 and a light-sensin~ element 318, which togethcr form a photoelc~tric dctector means, aro disposcd on the opposite sid~s 6 of the pas~age 316 in the chamber. Even during inoperative condition of thc copying apparatus, the passage 316 Or transparen;
8 material is filled with developing liquid so that toner will 9 never stick to the wall portion Or the passage 316 which corresponds to the optical path. Since the developing liquid 11 as injected from the conduit 319 is at a predetermined flow 12 velocity, such liquid will flow through the passage 316 while 13 diverging into a sector form. This will prevent toner from 14 sticking to the inner wall portion of the passage 316 which is exposed to the flow of developing liquid, but the rest of the 16 passage wall will suffer from sticking of toner. In other 17 words, unless the light source 317 and the light-sensing element 18 318 were disposed at locations corresponding to the area of !
19 the passage in which the developing liquid 314 flows in a sector form, no proper density of the developing liquid will be 21 obtained and this would necessarily lead to an increased si~e 22 of the passage 316. In order that the developing liquid 314 23 may be directed through the conduit 319, the pumping force must 24 be increased, otherwise the flow velocity of the developing liquid 314 would be reduced to cause toner to stick to the wall 26 of the passage 316.
27 Description will rurther be made of a construction 28 wherein a pumping mechanism including an impeller and a casing 29 forming a spiral chamber is provided in developing liquid and 3o a portion of the casing is formed with a slit-like or other ~ ~7 - ;

: ;~

1 OE)Ollin~ tllrOU~Il W~ l ttl~ d~vclopin~ liquid may be directly 2 p~ed to thc p~ss~o ia th~ photoclcctric dotector means.
3 Rercrring to l`igurcs 26, 27 and 28, a casing 320 forming ~ pump d~rin~j a spiral ch~mber 321 thercwithin and accommodate~ thcrein an impellcr 322 rot~table in the direction 6 of arrow, The impell~r 322 is directly co~nected to a motor 7 shaft 323. A portion of the ca~ing 320 is formed with a ~lit 8 324 as opcnin~. A dcnsity dctcctor chamber 325 acco~nod:~ting 9 therein a light source 328 and light-sensing element 327 for detecting the density of the developing liquid 314 i5 provided 11 with a passage 326 f~rmed of glass, transparent plastics or 12 other transparent material. The passage 326 is attached to the 13 casing 320 for engagement with the slit 324 formed in the 14 casing 320. ¦- :
In the developing liquid density detector device 16 constructed as described, the developing liquid 314 is drawn !: -in through the liquid intake port 329 of the case 320 by ¦ -18 rotation of the impeller in the direction of arrow a and the 19 pressure of the drawn liquid is increased in the spiral ; 20 chamber 321 to increase its flow velocity, and then the liquid 21 is delivered through the opening 330 to the developing portion 22 (not shown) for developing an electrostatic latent image.
23 Likewise, the developing liquid 314 is alxo inJected rapidly 24 through the slit 324 to the passage 326 in the photoelectric ~i 25 detector means.
~l~ 26 Since the developing liquid injected from the spiral 27 chamber 321 is delivered through the slit 324 to the passage ~! 28 326 in the photoelectric detector ~eans while keeping a great 29 width of flow but without the flow velocity thereof being 3 reduced~ toner will never stick to the transparent wall portion - 48 _ :', " . i .,.

~i . 1 0 6 4Z4 9 1 ol t}le ~ ge 3~G. I`v~n ir ~n~r ~hOUl~f stick to the ~all 2 portion of the p~s~a~e 3~6 during down-time of the copyin~
3 apparatus, sllch toner may readi y be removed by the dcveloping 4 liqui~ rapidly flowing out Or the slit 324, thus en~uring propor den~ity d~tection Or thc dcveloping liquid to bc achieved. In addition, thc developing liquid 314 flows out at a high velocity in accor~fancc with the shape of the slit 324, 8 and this enables the si~e of the detector chamber 325 to be i-9 minimized.
To maintain the developing liquid at a constant 11 density by the use of the above-described density detector 12 device, use may be made of an electric circuit for operating a 13 toner supply valve by a signal from, for example, the light-; 14 sensing element 326 and light source 328 forming the f photoelectric detector means. More specifically, a switching 16 transistor may be operated by the voltage at the junction 17 between the resistance of the light-sensing element 327 ~nd a 18 regulating resistance to permit a current to flow to an 19 electromagnetic solenoid to operate the valve.
Fixing Device 21 Figure 29 shows a copying machine of the transfer type 22 in which a liquid-deveIoped image on the surface of a - ~ 23 photosensitive dru~ 331 is transferred to copy paper (tran~fer 24 paper) P, which is then directed over a separator roll 335 onto ~f 25 a heating plate of a drying-fixing portion. The heating plate I ?6 is not restricted to the shown form, but the heating plate 336 :f z7 has mica-enclosed plate-like electrical heaters 337,338 and 28 support plates 339,340 secured to the back or lower side 29 thereof by bolts and nuts 348, and they are supported on a 3 support frame 350 by means of mounting leg 349. ~he upper . - ~ .
~, 49 1()6~49 1 ~urrac~ ~1` tl~c ~loll~in~ IJla~ 336 is shown to compris~ ~ fir~t 2 concave surf~cc portion and a second convex surface portion, 3 with S~ po~ w;lr~ o~ copy p. !~r ~urin~ heatin~ in~
: 4 taken into ~ccount.
The surfacc Or tho above-dcscribcd hoatin~ plate 6 336 (including the front and rear e~tension surraces) may be formed with ono or mor~ hol~ 341 and ~roov~ 334 (Figuro 29), 8 or alternltively the front and rear portions Or the surrace of :- 9 the heating plate 336 may be formed with grooves 342-344 ;j 10 (Figure 30) ~ and these opening~ may be communicated with a 11 suction source through duct~ 345-347.
12 In Figure 29, when the copy paper P has reached the 13 intake groove 334 via the separator roll 335, the copy paper is :.l 14 attracted to a guide line (or netting) 332 by air drawn from :` 15 the groove 334 by a blower 351 through an intake regulating S ~ 16 chamber 333 and duct 346 while the copy paper is advasnced 17 riding onto the inlet end Or the heating plate 336 located on ~ :
. 18 the extension of the guide line. Since a number of holes 341 19 are alternately formed in the surface of the heating plate, the copy paper P is advanced with the leading and trailing edges 21 thereof attracted into intimate contact with the heating plate :t-~ ~ . 22 surface by the suction forces from these holes. Thus, the .~,.,~ . .
~- 23 copy paper P, which would tend to be curled by heating, is 24 brought into intimate contact with bhe heating plate by the suction so that the copy paper can be subjected to heating . ~ 26 effect by the entire surface of the heating plate, with a re~ult ~: 27 th~t a sufficient drying and fixing ef~ecb is attained through 28 a relatively short di~tance of travel.
When no copy paper is present on the drying-fixing 3~ 3 device, even if the suction blower 351 is in operation, ~o~t .,.

':. - 50 -i.~ ~

~ . ~
, 1 of t}lC dr.lWn UiI` will ~ throu~h the intakc ~roove 334 ~Id 2 only very littl~ ol` t}le air will pass through the intake p~rt 3 341, b~c~u~o th~ intalcc ,~roovc 33LI h~ a cross-sectiorlal aro~
4 much greater than th~t Or the intake port 341 and because the duct 345 is bent with rospcct to the int~ke port 341 to provi~
6 a gr~at line ro~istancc. Th~rcfore, th~ temperature fall of 7 the heating plate which would result from the provision Or tho 8 intake port 341 is substantially nogligible. Also, when a sh,l~et 9 of copy paper P has been conveyed there to cover the intake port 334, the amount of air drawn in through the intake port 11 341 will be increased and the air will strongly attract the 12 copy paper P at a point of time whereat the paper has reached 13 the intake port, thereby bringing the copy paper into intimate contact with the heating plate for efficient drying and fixing.
Figure 30 shows an embodiment wherein in lieu of the 16 intake port 341 in the surface of the heating plate, elongated 17 intake grooves 343 and 344 are provided in the center of the 18 heating plate surface and on the surface of the rearward 19 extension, the grooves extending widthwlse of the heating plate.
Discretely from the intake groove 342, a blower 352 21 is provided to ensure intimate contact of copy paper with the 22 heating plate.
23 Further~ by providing a suction effect only in the 24 presence of copy paper in the drying-fixing portion, it will be possible to minimize the temperature fall of the heating 26 plate and keep the durability of the electrical heater. For 27 example~ a control circuit 353 may be provided to operate tbe 28 blowers 351 and 352 in timed relation~hip with the arrival Or 29 copy paper from the paper feeding cassette. Alternatively, a control 356 may be provided which is operable by a signal from .:

1~:)64Z49 l ~n clcctric~ n~or 3511 (usin~ CdS, micro~witch or thc liko ) 2 for detecting thc leadin~ edgc Or the copy paper in the vicinity of thc inta1;e ~ V~ 334 .In~ ~y a ~i~nul from a ~imilar 4 electrical ~ensor 355 for detecting the trailing edge Or the copy papcr ju~t rearwardly of the heating plate.
6 The temperature of the heating plate may be low~r than 7 the conventional level and thc distance Or travel o~ copy papor 8 may be shortened to achieve a sufficient drying-Pixing efPsct 9 and to reduce the size and weight of the device. The present embodiment is equally applicable for the fixing Or copy paper in ll dry type copying machines.
12 Figure 31 shows a commonly used heater oP the heatin~ -13 plate type. It comprises a convex-surfaced heating plate 375, 14 a plate-like heater 376 and a support plate 377 having a curved ~ -surface similar to that of the heating plate. The heater 376 16 i8 brought into intimate contact with the heating plate 375 by ;~
: 17 bolts 379 and 380 threaded into a unitary bottom plate 378.
- 18 The invention will now be described with respect to ,-~ 9 an embodiment as shown in Figures 32 and 33. The photosensitive : 20 drum is herein designated by 331 ~ and copy paper P having an 21 image tran~ferred thereto Prom the surface oP the photosen~itive ~;~ ~drum 331 is separated from the drum by a separator roll 335 and 23 a separator belt (not shown), and then delivered onto the 24 heating plate of the drying-fixing dev~ce A. As it passes over the upper surrace of the drying-~ixing device A~ the copy paper - --26 P iq dried and fixed by the heat Pro~ the heating pla~e 36l and ~ 27 discharged by a set of di~churge roll~ 3s7 into a tray (not ;;~ 28 shown) located outside.
29 In Figure 33, the heatin~ plate 361 is a metal plate 3 of good heat conductivity compri~ing a concavely curved -~ ' . _ .

1064~49 1 sur~ce 358 of curv~ture r~diu~ nl w~lich is the inlet portion 2 for copy paper, a conve~ly curvcd surrace 360 of curvatur~
3 r~dius ~z wl._cll is t~l~ outl~t ~)~rtion ror co}ly p~per, ~nd a 4 narrow flat portion smoothly interconneeting the two curved surfaces 358 and 360, The tangential line 363 at the inlet end 6 362 of the concavely curved surface 358 lics flush with or below the p~th 36l~ o~` tllo incoming p~per, and the curvature 8 radius Rl of the surface 358 is selected such that, when the copy paper has touched the heating plate, it is urged against the heating plate and also smoothly deflec-ted by the suction 11 air from ports 365,366 or warm wind imparted from above the 12 paper. The curvature radius R2 of the eonvexly curved surface 13 360 is selected to a value substantially approximate to the 14 eurvature radius with which the paper is eurled when heated. -When the copy paper P is delivered from the separator roll 335 16 onto the upper surface of the above-described heating plate 361, 17 the copy paper P first touches the inlet end 362 of the 18 concavely curved surface 358 and is urged against such surface 19 - and deflected while being gradually heated, and advanees to `
the flat surface portion 359. By that time, the paper will have 21 been dried to some extent and warped inwardly, Thus, when the 22 leading edge of the copy paper P has come to the convexly 23 curved surfaee 360 past the flat surface 359, the leading edge 24 portion of the copy paper P will lower from gravity and eome into uniform contact with the eonvex surfaee 360 beeause the 26 eurvature radius of the convex surfaee 360 is approximate to 27 that of the eurled paper. The degree o~ intimate eontaet 28 between the eoneavely eurved surfaee 360 and the eopy paper P
29 may be further inereased when the eopy paper i9 drawn leftwardly and downwardly by dlseharge rolls.

1064~49 1 T~lu~, tll~ c~}~y ~ p-~r co~ne~ into COIIti~Ct with tho 2 heating plate 3Gl over the entire area thereof iso that the 3 heat rronl ~he hc~ti~ latc continuou ly transfers to the copy 4 paper to accolllpli~ll ideal drying and fixing.
Plate~ lleater~ 367 and 368 each compri~e a 6 plate-like nichromc wire flatly wound on a mica platc and 7 having the oppositc surface~ covered with layers of mica for 8 insulation and protection. These heaters have dimensions 9 corresponding to the dimensions of the curved surfaces 358 and 360, respectively.
11 Support plates 369 and 370 for the heaters and metal 12 plates have dimensions substantially equal to the dimensions 13 f the heaters. The support plate 370 has a curvature radius 14 substantially equal to or slightly less than the curvature radius R3 of the back side of the curved surface 358, and the 16 support plate 369 has a curvature radius substantially equal to 17 or slightly greater than the curvature radius P4 of the back 18 side of the curved surface 360.
19 Bolts 371 iand 372 are provided substantially centrally of the curved surfaces 358 and 359 of the heating 21 plate 361, and have one end secured to the heating plate 361.
22 These bolts are respectively aligned with holes formed through 23 heaters 367,368 and support plates 369,370 substantially 24 centrally thereof, and cooperate with nuts 373 and 374 to isecure the heaters 367,368 with support plateis 369,370 to the 26 heating plate. In such heater holding system, the force urging s 27 the heaters against the curved surfaces may concentrate in the 28 centers of the heaters to thereby bend the hard mica eaiily and 29 well adapt the heaters to the heati~g plate. Particularly, 3 unlike the case of Figure 31 where the heating plate is . ~ _54-10~4;~49 1l 1 f`a~ten~ at tll~ o~ ait~ tll~r~ol', thorc i~ no force w}li 2 convert~ tllc conv(~xity to tl~c concavity or vice versa and t~
3 results in n~ dcro~ lti~n of the curved surfaces. Accordingly, 4 bettcr contact of tllc }l~ater wlt~l the }leating plate i~ provi~
to prevent the nic~lromc wirc from b~ing partly heated red and 6 broken. Also, th~ ovorall contact established between the 7 entire heater surrace and th~ heating plate and the natural 8 construction of thc fastening mechanism permit the heating 9 plate to be thin and of low heat capacity, which in turn lead~
to an ease of temperature control and shorter length of time ~; 11 required until the desired temperature is attained.
12 The plate-like heaters 367,368 and the support plates 3 369,370 need not always be separate members as shown, but may 14 be formed integrally. -Referring now to Figure 34, there is shown an example - 16 of the transfer drum type electrophotographic copying 17 apparatus. Around a photosensitive drum 357 rotatable in the 8 direction arrow, there are disposed various process elements 19 such as a primary charger 358, a simultaneous image application and discharger 359, an overall irradiating lamp 360, a 21 developing device 361, a post-charger 362, an image transfer - 22 portion 363, a residual image cleaner 364, etc.
23 A sheet of transfer paper P may be fed from a cassette 24 or li~e paper feed box 365 or 366 by means of a roll 367 or 368 and rolls 369, 370 and~ behind the post-charger 362, the paper P
26 may be urged again~t the photosensitive drum 3S7 to have a 27 toner image transrerred thereto, whereafter the paper may be 28 separated from the drum by a separator roll 371 and a sepsrator 29 belt 372 and direcred onto a heating plate type fixing device 3o ll 373~ whern e paper nay be conveyed rOr drying and fLxing . -55-,, _1 - ' ~

1064~49 1 wllilc bein~ brou~}lt into intillluto contuct with thc hoating plat-2 373 by thc -~UC tion air I`rom a duct 374 and by a blast of air 3 from a duct 375, wllorcai`t~r the papor nay finally be discnargod 4 through a port 371 onto a tray 377. Designated by 37~ and 379 . are transfer pauer guide passages between the set of feed rolls .~ 6 369,370 and the photosensitive drum 357.
.~ 7 A drying-fi~ing portion 380 is divided into an upp~r .: 8 portion 381 and a lower portion 382 by a copy paper pa4sage, ~ 9 and these two portions are coupled together by links 383 and : 10 384. A transport roll 285 and a blow-out duct 375 are mounted 11 within the upper portion 381, and a charger 363, transfer paper 12 separator roll 371, belt 372, duct 374, heating plate 373, .. ~ 13 roll 286, guide plate 387, reflector plate 388, rolls 389,390, 14 etc. are supported within the lower portion 382.
~; A pivot shaft 391 is provided below and righ~wardly ~ 16 of the lower portion 382 and pivotally mounted to a plate frame .i 17 392. A lever handle 393 is pivotally mounted.on a shaft 394 ~ 18 to open the upper portion 381 and pivotally move the lower `~ 19 portion 382. A lever 395 is also mounted on the shaft 394 inside the plate frame 392. A slider 396 is mounted for .
¦ 21 oscillation on the end of the lever 395. A slide shaft 397 22 i8 provided in the lower portion 382. A lever 398 is integrally '~ 23 formed with the link 383 and has a slot 399 formed therein.
24 A pin 400 is provided on the plate frume 392 and engaged in the slot 399.
26 - In Figures 34 and 35~ the upper and lower portions 27 381 and j82 are closed and the image transfer portion 363 is 28 maintained in its proper position relative to the photosensitive 29 drum 357. Slight withdrawal of the knob 401 o~ the lever handle 393 may cause the lever handle to be disengaged from the mating ~.' : _ 56 - `.,.

1 holc in tl~ otc ~r.lnl~ 3'~ y pivoting tho lcver ll~ndle 2 counter-clockwi~e to tll~ pu~ition indicatcd by dot~-und-dash 3 liilc, th~ r l~ will c... u~c 't~ r !~o3 and ~lid~ a~t 4 404 to pivot the lowcr portion 3~2 downwardly about the shart 391 and incline t}lo ~1110 ~w~y rrolll t~l~ photoYon~itivo dru~l 357 6 as shown in Figures 36 and 37.
7 As the lower portion 382 is so inclincd, the lever 8 398 is cocked by the pin 400 on the plate fr~ne to cock the 9 link 383 to substantially upright position about the pivot pin 405 by which the link is pivotally mounted to the lower 11 portion. This also causes the parallel link 384 to cock 12 upright, whereby the upper portion 381 is lifted high with 3 respect to the lower portion 382, as shown in Figures 36 and 37.
14 Also, as the lower portion 382 is inclined, a pawl 49 near the pivot shaft 391 moves the shaft of the transport 16 roll 369 to separate this roll from its partner roll 370.
17 Further, the guide plate 387 in the lower portion 382 is cocked 18 up by a spring 411 because a keep member 410 for the guide 19 plate provided in the upper portion 381 is separated from the guide plate. By manually pushing the guide plate 379, it may 21 be widely separated from the guide plate 378.
22 Thus, a single operation of the handle 393 can widely 23 open almost all of the paper passages from the first transport 24 rolls 369,370 to the guide plates 378,379 and betwecn the separator belt 372 and the photosensitive drum 357 and further 26 between the upper portion 381 and the lower portion 382, so 27 that anyone can easily obtain access to any Or these passage~
28 through a hole 414 in the plate frame 392 of the apparatus . .~ ~ housing to properly deal with the transfer paper if jamming should occur.

11~64Z49 'i ':
I'<~ r 1`~ r l)evi.c~
2 l~eferring t~ urcs 38 ~n~ ~9, intermedi~te plates 3 501 and 502 c~rrying thcreon sheets Ot` Copy paper P arepivotable about their endvi opposite to their copy paper feeding ends and are normally biasod at the copy paper feeding 6 ends by sprillgs 503 to raiso separator pawls 504 which àre thc 7 means for separation of copy paper. The separator pawls 504 are pivotally mounted to side pl~tes 505 and 506 and movable 9 from gravity downwardly from an upper limit determined by a stop 510 to at least a position for effecting feeding i 11 operation. (This lower limit is determined by a stop 511.) 12 A feed roll 512 provided in a copying apparatus is 13 rotated and lowered to depress the stock of paper sheets P to 14 the feeding position. Thereupon, a direct pressure force from the springs 503 acts between the feed roll and the stocX of 16 copy paper P and a proper frictional force (feeding force) 17 resulting from such pressure force and rotation of the feed 18 roll cause an uppermost sheet of copy paper to be fed. At the 19 same time, the separator pawl 504 comes down into contact Wit}
the stock of copy paper P from gravity and separate the 21 uppermost sheet of copy paper.
22 More particularly, in the position shown in ~igure 41, 23 each spring 503 has one end secured to a feeder bed base plate 24 and the other end secured to a spring receiving plate 509 which is vertically movable.
26 Thus, exactly, the intermediate plates 501 and 502 27 take the spring forces from the spring~ 503 through the ~prlng 28 receiving plate 509 to raise the separator pawls 504. The side 29 plate 505, with the intermediate pl~te 501 and the separator pawl 504, is movable along a rail 507 to limit the copy paper .
...
: - 58 - , ln64zss 1 P to ~ suit~ble l)o~ition in accord~nce with the si~e thereor.
2 TJl~ movelllent ol` th~ pl~t~ may be ~ccomplished by mean~ ol`
a leve:~ 508.
4 Thi~ systom offers ~ problem that, when the interlllediate plate ~nd th~ i~ide ~late are ~oved in accordance 6 with a ~mall size Or p~p~r, as ~hown in ~igure 41, the distanc~ ;
7 between the spring 503 and the feed roll 512 creating the feeding force differ~ between the left and right sides of th~ -9 apparatus, which results in a difference in pressure contact force and accordingly in feeding force between the left and 11 right sides, thus causing copy paper P to be fed obliquely.
12 Referring to Figure 42, each spring 503 has one end 13 secured to the lower bent portion of the side plate 503 and 14 the other end secured to the intermediate plate 501, so that movement of the side plate 505 will cause simultaneous 16 movement of separator pawl 504, side plate 505, intermediate 17 plate 501 and spring 503 which are all integral with one 18 another.
19 With the above-described construction, movement of the spring does not result in any variation in the relative 21. position between the feed roll 512 and the copy paper 22 . irrespective of the size of the copy paper, and a uniform 23 pressure contact force is maintained to ensure the feeding 24 force at the left and right sides to be balanced at a con~tant ~:
level to enable stable feeding.
26 The present embodiment has been described as an 27 application to a copy paper feeder bed in copying machine or 28 the like, whereas it is not restricted to copying machines but is equally applicable to feeder beds for thin layers Or paper, 3 metal, plastics or like material.
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10~4'~4~
, 1 Al~o~ ur~ t~ o~ te 513 is mounto(l oll t}l-~ col,y ~ )cr l`~odill~ ol` the l ~t~-lor bcd for nlovelllcnt 3 in tllo dir~cti~rla ol` ~rrows A ~nd ~. rl~ nd of th~
4 projection 514 Or ~hc detcctoI p1atc is engaged witll the sid~
platc 505 ~nd norm.-lly bi.ased in the diroction A by a ~pring 6 5~5.
7 Microswitchcs MSl and MS2 for detecting the sizc of : - copy paper are ~ecurcd to the machine body and designed such 9 that they are opened when their actuators pass through an aperture 516 and cut-away 517 in the detector plate 513 and 11 that they are clos~d whcn thcir actuators do not pass through~
12 the aperture and cut-away. Therefore, if the side plate 505 13 is moved to match the size Or the copy paper, the aperture 516 ~.
14 and cut-away 5~.7 in the detector plate 513 will also be :.' 15 displaced to open and close the switches MSl and MS2. The 16 switches MSl and MS2, as shown in Figure 44, are connected to :~ 17 indioàtor lamps Ll, L2, L3, L4 provlded at suitable locations 18 of the machine and one of these indicator lamps Ll-L4 may bc 19 turned on at a time in accordance with a combination of ON and OF~ of the switches MSl and MS2. ;
21 In the above-described embodiments, it is shown that - 22 two switches are used to detect four different sises Or sheets, 23 but generally the r.olation between the number N to be detected 24 and the number n of the necqssary switches may-be obtained by an equation: As described, a necessary nwnber i 26 . N = .~ nCx, ,' . ' ' ' x=O~ ' 1 27 Or size detection indicator switchos aro rolatcd to the ~ide , 28 plate, and tho~c switchos are inserted in the energizing circuit 29 for the indicator lam~s to turn on a predcterminod one Or the indicator lamps at a time in accordanco with tho siæe of the . , ..
~Or)y l);ll)~r tll~`JI ~I`I`i~ rl t~ t!r bc~. Tllu~, the ~i~e ot 2 ~ ,y l);~ r ~ll t~ ly ~ ly .~ r~ ily ~e ~ ~'UIII'il'lll(`(.l .1~ ~lly tilll~ Ll~ y ~ V~ cu~ Or 4 In~ll`unctionin~ an~ ~'nllOIlCC tllc ollicioncy Or ollice work.
. 5 Ot~ r ~vico~
.- 6 nerorrin~r to Figuro llll, i t ~tlOW~ an apparatus 7 hou~in~ ~01, an ori.ginul c;lr:r:iugo Go~, guido rail~ 603 along 8 which the original carri~g~ i~ rociprocally moved, an original 9 keep co~er 604 having a handlc 605, a reversible motor M~ a drum shaft 606 and a drum 607.
¦ 11 Depre~sion of a copy button cau~o~ rorward rotation -~ 12 Or the motor M which in turn causes rorward rotation of the J~ 13 druln 607 in the direction F through the ageney of gears 608 .14 and 609, 60 that the original carriage 602 i9 moved forward in the direction F by meàns Or a wire wound on tho drum 607.
16 Arrival of the original carriage at the end of its forward 17 stroke is detected to produce a detection signal whieh reverses ~ 18 the rotation of the motor M, whereby the above-mentioned various .1 19 parts assume baekward movement in the direetion B until the original earriage 602.is stopped at its home position shQwn in ~ ~ 21 Figure 44. ;
: ~ 22 An origlnal on the original earriage ls illuminated 23 : during the, above-described.forwQrd or baekward stroke~ and the original ea~riage 602 i~ temporarily stopped after eaeh ~ ~ 25~ ~ :reeiproeation~ and restarted by a subsequent eo~mand, : ~ 26 ~ ~erore the origin~l earriage reaches its home .~ 7 position~ the power su?ply to the motoF M i9 eut of~ and the ~- 28 earriage later move ~aekward rrom inertia. During that timo, a ero~s bar or proJectlon 611 provided on the original earriage 3 engages an engagement member 612 on the apparatu9 body and ,,,, . .
i - 61 -:i ~
~ .j . ~ .'?~ ~7~

1064~49 1 III~VI`S l>;l~ it;, ~ tll~ n~.t~ nL Il~ r Z C~l)WIdS sl~l'il~gs 613 t~ pl(-vid(: Ll bull~r.
3 ~rhe ~I.O~ posi.tion" llercin ui~d is a position at whicl-4 t~le s~eed of the origirlal carriage is reduc~d to ~ero by the resist~lce Or th~3 springs ~13 arld co"~cs to a halt~ and the 6 present invontion also rclatcs to me~tls ror locking the 7 original carriage at such position.
8 An examplc of such means is shown in Figuros 45 to 9 47. Whcn the drum shaft 606 i~ ~topped as deccribed~ it tends to be moved forwardly in the direction F by a great magnitude 11 of energy accumulated in the ends of the burfer springs 613 12 (which energy provides a starting energy which will be described), As a result, a clutch spring 615 formed by a 14 rightwardly turned coil spring relatively tightly wound around a brake cylinder 614 securc~ to the drum shaft 606 is further 16 tightened and coils around a brake cylinder 617, secured to a 17 frame 616 j to thereby lock the drum shaft 606 against rotation 18 in the direction F, thus stopping the original carriage 602 19 ,at its home po-iition.
Prior to .the above-described operation, during the 21 rotation of the drum shaft 606 in the direction B, a control 22 plate 620 held between a spring receptacle 618 and the 23 aforesaid~brake cylinder 614 with a rriction plate 619 -~!~
24 interposed:therebetween is urged by a spring 621 and rotated : in the direction B by the frictional transmission from the brake 26 cylinder 614 until it strikes a stop 622 as shown in Figure 46, 27 whereupon à control pin 623 liberates a control pawl 624. As a 28 result, the control p~wl 624 is pulled by a spring 625 with the 29 inclined surface 632 Or the pawl ~uided by a pin 626~ 90 that 3o the control pawl 624 1~ inclined about a pivot pln 627 and out ~ .

_~, ~j l ~ d'~'~i' ~

~ 1064Z4~t I 011~ W.; ~ Wll~ 11 ;1 COII~I'L)1 rillL~ G ~3 1OJ~ tll(` ~ L~ l.
3 Thus, tJIo colltru] rillg ~'~ rostr.lining OJIO Cnd 633 Or tho ClUtCIl ~I)ring G15 p~rll~it~ t)l.i.S c,lutch ~pri~g to tighten in th~ direction ~` pur~u~nt to tllc~ bruko cylindor 614.
6 ~lell the copy button is dopro~sed, a solonoid 631 i~
7 clectrically energiYed to causo a plungor 630 to attract the 8' control pawl 624 in tbe manner as shown in Figure 47. The 9 control pawl 624 meshes with thc ratchct whcel 629 to rotate the control ring 628 counter-clockwise and thereby loosen the clutch 11 spring 615 to unlock the drum shaft 606.
12 At the same time, the motor M is also rotated to 13 rotate the drum 607 in the diroction F. At that time~ the 14 force accumulated i~ tho burfer ~prings 613 act~ a~ the rising torque for rotation~ and this enables quick starbing 16 rotation of the drum shaft 606 even lr the motor is an AC motor of small starting torque.
18 Such quick startiNg is particularly userul when the 19 device is applied to a copying ~nachine, for example. The reason is that the original carriago must quickly abtain its con~tant 21 velocity and a ~mall drive force is only required once the 22 constant velocity has,been attained.
23 ~;otation of the drum shaft 606 in the direction F
also causes rotation'or the ~ontrol p}ate 620 in the ~ame ,direction, so that the pin 623 thoreon cngages a stepped 26' portion 634 of the control pawl 624 to maintain the oontrol 27, pawl in mesh engagoment with the ratchet wheel 629 even a~ter 28 cut-ofr Or the power supply to tho solenoid 631~ thus 29 restraining the contro,l ring 628. Thererore; even if the 3 input,signal to the s~lonoid 631 is of ~hort pcriod~ the lock .

, ~ - 63 -1116~Z49 1 ~y ll~ y l~ lll;lillt;li~ ~' ~ S ~ o n 6 ~ L th~
~ ~II.-l`t G~G i~ rot;t~ l tll~ llir~tion 1`.
3 Thc a~o~ k!~ribc-l sprirl~ clutch mocllani~m act~ a 4 u xpoci-ll one-wuy clut~h W~ ll is Sl~ t op~rative during tlle l~rwlrcl (I~`) a~ld backward (I~) nlovclllcrlt Or thc origillul carriago 6 602 but o~rect~ locking only wtlen thc ori~inal carriage tcnd~
to be movcd forwarcl bv the enorgy Or the buffer springs 613 at 8 thc momcnt the carriage comes to a halt at the home position g which is the end of the backwurd ~trokc.
Another embodiment which is capable of effecting 11 such action is sho~m in Figure ll8.
12 For example, when a br~kc rod 635 provided on the 13 original carriage 602 is move~ in the direction B of backward 14 movement of the carriage to strike a stop 636, it forcibly constricts a buffor spring 637 while being thereby decellerat-ed 16 to zero velocity, thus coming to the home position. When the 17 original carriage tries to revert to the forward direction F
18 with the aid of the rcpul~ion ~f thc buffer spring 637, a brake 19 cam 638 and a guide roller 639 hold and lock the brake rod 635 therebetween.
21 Vhen the copy button is depressed, a solenoid 640 22 is energized to rot;ato the cam 638 clockwise to unlock the brake 23 rod, and ~he spring 637 now serves to assist i~ the'starting 24 torque, The foregoing embodiments have been shown to employ 26 spring~ as the energy accumulator, whereas this is not the only 27 possible form but us~ may bo mad~ o~ any mcans which can 28 accumulate and discharge kinctic ~norgy (such a~ pnewnatic 29 springs, rubber or the liko), ~-Thus, the present~mochlmisnl can fully alloviate a ' . , ' .
_ 61~ _ 1 sllocl; in t~ t it c~llv~!rt~ tll~ k-inctic onorey Or a moving body into a l~telltial ~tlcrgy ol' sl-rillg wili.].o decelloratillg the 3 moving bo~ly t^ a ~u~lt. l'~`urt~lcr, it c~n rclativ~ly ~imply bo 4 constructod by thc u~o Or ollorgy ubsorbing xprin~s and a onc-way clutch mechanism arld this l.eads to a high reliability 6 and low cost Or the mochani~m. Furthormoro, when the moving 7 body is to bc moved in tho opl~osite direction, thc onergy 8 accwnulatcd in the springs assist,s in the rising of the movement -.
in the oppositc direction and it is thux possible to realize quick starting and effective utili~ation o~ the energy.
11 According to tho prior urt, thc photo~cnsitivo drum 12 has bocn supportod,'~s showrl in Figure 4'3, by rigidly coupling 13 the fixed end of the drum shaft 701 to the bottom plate 702 of 14 the machine by means of a support member 703.
With regard,particularly to the deflection of the 16 support membcr 703, it is the d~flection angle of that portion ~ , 17 'of the support member 703 fixing the drum shaft 701 which 18 imparts a displacement to the drum 706. The deflection angle 19 i may be expressed as;
i = EI ~
21 . . ' , . :
22 where M is,a moment produced in the. suppo~t mem'oer 703 by the 23 weight W of the drum 706 and is a result o~ the weight W
24 multiplied by the length 1 from the support member to the load point of the drum shaft 701, and a, E and I are the length, the 26 Young~s modulus and the principal moment of inertia of area, 27 respoctively, of the support mor,lber 703. .
28 As will b'e soen rroul tho u~ovo oquation, a smallor 29 valuc ror a is advisable to proviclo tl~o ~rwll ~hart 701 with ,rigidity. 'According .i-o this mothod, tho d-LIllonsioll a ix 10~4Z49 detenmined by other factors and therefore, the section ~odulus must unavoidably be increased for compensation. Also, as shown in Figure 50, the moment M = Wl covers even the bottom plate 702, so the bottom plate must also be rigid. Thus, such a cantilever construction usually leads to increased dimensions and greater weight of the structure, whicb would unavoidflbly incur high shipping expenses of the machine.
Another cantilever-fahsioned supporting method is illustrated in Figure 51. This comprises attaching a support mem~er 705 to one side plate frame 704 to cause the moment produced in the fixed end of the drum shaft 701 to be dissipated in the side plate frame 704 and thereby provide a -support, but such method is only suitable for very s~all machines and not for medium- or large-size machines.
Referring to Figures 52 to 55, there is shown a method which enables a rigid cantilever to be fixed to a ~
light-weight (and thus somewhat weak) machine body. ~ -Figure 52 shows the main housing 707 of a copying machine~ a reciprocally movable original carriage 708~ plate~
like frames 710 and 711 for assembling various devices thereto, the frames being coupled together by a stay (not ; shown), and a bottom plate 712. The rear side frame 711 is -provided with a support member 714 of alloy casting substantially centrally thereof for supporting a drum shaft 713, `~ 25 and the trum shaft 713 is firmly fixed to the support member.
A gear 715 is mounted on the drum shaft 713 and rotatable by ball bearings~ and driven from a main motor (not shown). The drum gear 715 has a pin 716 fixed thereto and driving a drum unit 719 which comprises a photoJensitive drum 706 or the like inserted over the shaft 713. m e idle end .: ~
.,:, :~ . , , ,;

~ 64'~49 1 (th~ ri~lt ~n~J il~ uro 51) oI` t~lC ~rw~ h~rt 713 may bo 2 ~ >pGt~t~ by ~l ~u~ ort Utlit 718 inclu~in~ a supp~rt metal 717 . 3 or t~-c lik~, to en~uIc th~ safoty Or t~le drum ~hurt in thc ; 4 event that ~n ~xcos~ive load ix exortcd thcreon for some r~on or ot~lcr. Thi~ support Wlit is for thc purpose of 6 safety and is not always noccs~ ry. Tho support unit 718, as 7 shown in Figure 53, i8 fixcd to the fraMe 710 by means of throe 8 scrcws 719-721 and readily rcmovable whon tho drum unit 719 is 9 to be r,cmovcd from the shart 713.
Support bars 722 and 723 are firmly fitted to the ~ 11 lower portions of the support member 714, and the other ends *, -i 12 of these support b~rs 722 and 723 are securely fixed to the -: 13 frame 710. The support membcr 714 i~ also fixed to the frame 14 711 by a plurality of Bcrews 724.
With the~above-desoribed construction~ the drum shaft I 16 713 may provide a rigid canbilevered shaft because the shaft 17 713 is supported to the frames 710 and 711 over a wide span by 18 the support member 714 and,tho support bars 722,723 and because 19 the dimension a Or th~,support mombcr 714 is 90 small that tho rigidity thereof is relativèly increased.
, 21 Figure 54 i9 a perspective view showing the drum 713, ~' 22 support member 714 and support bars 722,723 of'Figure 52. In ; 23 th~ prese~t embodiment, the,cantilevered shaft 713 and the ~ , 24 support bars 722,72.3 àre arranged so as to occupy the vertices '~ 25 ; Or 'a regular triangle, whereas they ,are not restricted to such ~ - 26 ar~angement. The number of the support bars is neither ,~ 27 restrictod to two . - .
J 28 Figure 55 shows an embodiment in which two 29 cantilevered shafts 725 support ~ photosensitive belt unit 726 3 having a belt-like phctosens;itivo modium. A support momber 727 ; - 67 -~, ,.

-ll i ~t~
1(~64;~49 i.~ c.t~ ri~ J`i.,~ til-~v~r~ `t~ 7'!5, ~ lln~l ~u~)l)ort l)ul~s 7~ rc Lo~atccl at thc J'~ur corller~ Or the 3 ~-lpport mc~ r. The ~up~ort m~mb~ 7"7 is couplcd to onc 4 f~ c ol` t~lc Il~ body .ln~ t~ rr~ Or t~ ul~ort b~r~
: 5 7~8.aro coup~.c~ to the o~JIor ~`rulllo, .lS ill th~ CUS~ Or ~i~ur~ 5'.
In tllc shown cmbodilllcnts, thc support melllbor 714 (727) 7 and the support bars 722,723 (728) arc separate, but thcse may 8 be inte~ral. Further, the frames 710,711 are not restricted to ., 9 thc plcfte-like form~ but may be in a skeleton-like rorm. Also, in addition to the photosensitive drum 709, various photographic 11 process mechanisms are incorporated in the shown copying 12 machine, but they are omittcd for convenience.
1~ , m e above-described construction permits the frames 14 to be relativcly weak and this leads to reduction in the cost and weight of the niachine. Further,,the moment produced by the 16 cantilever support is talcen by support bars 722 and 723 and 17 does not affect the bottom plate and thus, the bottom portion 18 may also bc designed witll ~1 low co~t and'li~ht weight, wllich 19 ,means a cantilever-fashioned support structure effective and ~uit~blo r a var ety of m~chines ~nd app.r~tuses.

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., , . " '.
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Claims (14)

1. Electromagnetic apparatus, comprising means for forming an electrostatic latent image on an image bearing member, developing means for developing said image with liquid developer comprising toner particles in a liquid carrier, a container for holding a supply of said liquid developer, means for circulating liquid developer between said container and said developing means and a filter located in the path of circulation and arranged so that developer falls into contact therewith, in operation of the apparatus, such that coagulations of toner particles may be dispersed by engagement with said filter.

2. Apparatus according to claim 1 wherein said filter is disposed within said container and the arrange-ment is such that a portion of the filter is exposed above the surface of the developer within the container during said circulation of said developer and such that said developer falls downward into contact with said exposed portions of said filter.

3. Apparatus according to claim 2 wherein said exposed portion of said filter is positioned angularly with respect to the direction in which said developer moves downwardly into contact therewith.

4. Apparatus according to claim 2 wherein the arrangement is such that said exposed portion of said filter is immersed in said liquid developer when said circulating means is inoperative.

5. Apparatus according to claim 4 arranged so that the level of liquid in the container is reduced when the circulating means is in operation, relative to the level when the circulating means is inoperative, whereby said portion of said filter is exposed and immersed respectively.

6. Apparatus according to claim 1, including a first conduit connecting an outlet of said container to an inlet of said developing means and a second conduit connecting an outlet of said developing means to an inlet of said container, said conduits being for said circulation of said liquid developer.

7. Apparatus according to claim 6, wherein said first and second conduits are rearrangeable so that the container and developing means are isolated from one another and the outlet of the container is connected to the inlet thereof and the outlet of the developing means is connected to the inlet thereof.

8. Apparatus according to claim 7 wherein the end of said first conduit connected to the inlet of said developing means is disconnectable therefrom, and reconnectable to the inlet of the container; and the end of the second conduit connected to the inlet of the container is disconnectable therefrom, and connectable to the inlet of the developing means, thereby permitting said rearrangement.

9. Apparatus according to claim 7, wherein each said conduit comprises a first part connected to the container and a second part connected to the developing means, said first and second parts of each conduit being disconnectable from each other, the first part of the first conduit being connectable to the first part of the second conduit, and the second part of the first conduit being connectable to the second part of the second conduit, there-by permitting said rearrangement.

10. Apparatus according to claim 1, including plate means disposed in said circulation path in the region of the inlet to said developing means, for reducing the velocity of the liquid developer fed to said developing means.

11. Apparatus according to claim 1 wherein the circulating means comprises an impeller disposed within said container.

12. Apparatus according to claim 1 which includes a photosensitive member on which latent images are formed in use of the apparatus, and said developing means includes a developing electrode disposed adjacent said photosensitive member, the arrangement being such that images on said photosensitive member are developed by supplying said developer liquid between said electrode and said photo-sensitive member.

13. Apparatus according to claim 12, including a spacer roller disposed between said developing electrode and said photosensitive member for maintaining a constant clearance therebetween.

14. Apparatus according to claim 12 or 13 wherein said developing electrode is movably mounted with respect to said photosensitive member.