JPS5820035B2 - Fukushiyaki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device for a copying machine, particularly a xerographic copying machine.

In addition to improving the quality of copies, future copying machines will also have extremely high copying speeds, and belt-type photoelectric bodies are currently being considered for this purpose.

However, this type of photoconductor is complex and must withstand fairly high processing speeds in order to actually perform high-speed copying. It is necessary to use multiple development units such as magnetic brushes.

When using such development brushes, it is easier to do so on a substantially flat portion of the belt so long as it forms a magnetic development blanket and can grow from one brush to the next.

Furthermore, by developing on a flat belt surface, the required gap between the belt surface and the magnetic brush can be precisely achieved.

One way to create the desired flattening in the belt is to bring them into contact using a platen support with vacuum suction means that attracts the opposite surfaces of the belt. In this case, the flattened belt running surface In order to take advantage of this, the developing device is installed on the opposite side of the platen, and the structure is such that a precise gap is formed between the developing unit and the belt surface necessary for proper development.

However, it is clear that accurate maintenance of the relative positions of the platen and developer, and their relative positions to other components of the copying machine, is dependent upon the rigidity of the support structure.

In the unlikely event that the support structure is displaced even slightly for some reason, the exact gap between the belt and the developer unit (
This has the effect of making image development inaccurate and undesirable.

Accordingly, a primary object of the present invention is to provide a new and improved copying machine.

A second object of the invention is to provide an improved development mechanism in high speed copying machines.

Another object of the present invention is to provide a floating belt support platen for use in belt-based xerography equipment.

Another object of the present invention is to provide a floating platen that can be used with a substantially flat belt running surface for image development.

Another object of the present invention is to provide a photoconductive belt support platen and a developer housing that can move in conjunction so that operating clearance is maintained in the event that either the platen or the housing is inadvertently displaced. .

Another object of the present invention is to provide a high-speed copying machine using an endless photoconductive belt, in which a developing means supported by the platen cooperates with and moves with the platen even if displacement occurs under unforeseen conditions. The purpose is to draw a floating belt running surface.

The copier of the present invention includes a flexible web having a photoconductive surface for forming and developing an electrostatic latent image of the original to be reproduced, and an internal frame member for supporting and guiding the web in an endless path of travel. a plurality of support rolls for the web rotatably mounted on the frame member to provide support for the web; a platen, web support means including means for tensioning the web to draw the web toward the platen to provide a substantially flat running surface during development of the image on the web;
When the frame member is unduly moved in order to move the platen relative to the frame member within certain limits to maintain operative contact between the platen and the web; and a biasing means for elastically pressing the platen against the web.

For a better understanding of the invention, its objects and other features, it will be described in detail below with reference to the accompanying drawings.

To aid in the general understanding of the present invention, copying machine 10 will be described.

In all electrostatic systems, such as the type of xerographic machine illustrated, a light image of the original to be reproduced is projected onto the intensifying surface of the xerographic plate, forming an electrostatic latent image thereon.

This latent image is then developed with an oppositely charged developer material to form an electrophotographic powder image corresponding to the latent image on the xerographic plate.

The powder image is transferred onto the support surface and fused thereon by a fusing device to permanently adhere the image to the image support surface.

In the illustrated machine 10, an original 12 to be reproduced is mounted on a transparent support platen 14 secured within an illumination device 15 located at the left end of the machine in FIG.

Light is projected onto the original image 12 on the support platen 14 from an illumination system including a flash image 17 and a reflector 18, creating a light image corresponding to informational areas on the original image.

This light image is projected onto an optical system 19 and thus a photoconductive enhancement of a xerographic plate in the form of a flexible photoconductive web or photoconductive belt 20 disposed on a belt assembly 21 .

As explained below, the photoconductive belt assembly 21
is slidably supported on two shafts 23,
The shaft 23 is fixed to the frame 9 of the machine 10 and is attached to drive the belt 20 at a constant speed in the direction of the arrow.

As the belt 20 moves, a reflected light image of the original image 12 on the support plate 14 is projected onto the xerographic surface of the belt, and an electrostatic latent image is formed thereon at an exposure station 25.

As the belt surface moves further, the electrostatic latent image formed at the exposure station is transferred to development station 2 where a development device is arranged.
6, where the belt 20 remains flat as shown.

When the light image passes through the development station 26, the development device 27
The electrostatic latent image is developed by multiple magnetic brushes 29 .

The developed electrostatic latent image is conveyed by the belt 20 to a transfer station 30, where it is exposed to the developed light onto a copy paper 32 which is conveyed between the transfer roll 23 and the belt 20 at a speed synchronized with the moving heald. The image is transferred.

The sheet transport mechanism 35 serves to transport the paper 32 from the paper grinding mechanism 36 to the transfer station 30.

After the transfer is completed, the paper is peeled off from the belt 20 and transferred to the fixing device 3T.
The xerographic powder image on the sheet 32 is conveyed to [
This will be fixed forever.

This final copy is ejected from the machine at the appropriate location and collected outside the machine.

The belt 20 is driven in relation to the irradiation exposure time timing to the original image 12, the developing device 27 is operated, and the paper transport mechanism 3 is driven.
5 and the paper-graining mechanism 36 are provided with drive means for operating them in accordance with the timing sequence of the original copy manufacturing process.

The belt 20 is comprised of a selenium alloy photoconductive aperture that provides the light-receiving surface on the backing material and serves as the imaging medium for the machine 10.

The belt is supported on three parallel rolls 40, 41, and 42 provided at each vertex of a substantially triangular shape so that it can continuously move.

During exposure of the belt 20, the belt surface is exposed to the roll 40 and the roll 4.
Between 1 and 1.

As shown in FIG. 3, photoconductive belt assembly 21 includes a photoreceptor belt 20 with a portion removed to show the mechanism of the assembly located adjacent to the belt.

The upper roll 42 has a general triangular side plate 44.4.
A hollow shaft 431 rotatably supported by the shaft 5 is rotatably supported.

An opening is formed at the upper apex of the side plate 44 to accommodate and support a bearing 46 that rotatably supports one end of the shaft 43.

The other end of the shaft 43 is similarly supported within a bearing 47 supported at the upper apex of the side plate 45.

A drive shaft 2 protruding from the support frame plate 48 of the machine and disposed within (along) the hollow shaft 43.
3 is formed with a conical member 51 and a small diameter extension portion 52.

Drive shaft 23 is supported on frame plate 48 by bearings 53 mounted on the frame and is coupled to a drive mechanism (not shown).

Conical member 51 is axially fixed and projects outwardly from frame plate 48 for engagement with inwardly tapered chamfered end 54 of hollow shaft 43 when the belt assembly is installed within the frame. .

The drive shaft extension 52 has a threaded shank 55 at the other end of the hollow shaft 43 .

This shank 55 engages a locking member 56 which is formed with a conical portion 57 which engages an inwardly facing face 58 on the outer end of the hollow shaft 43.

The locking member 560 is formed with a rotating manual knob 59 to facilitate removal of the locking member 56 when it is desired to remove the belt assembly 21.

The extension 52 of the drive shaft 23 is connected when the belt assembly 21 is in the operating position, i.e. when the side plate surface 45 is in the main frame plate 4.
When the 8G is in contact, it supports the belt assembly 21 and serves to rotate the roll 42 and therefore the belt 20.

This structure allows the belt assembly 21 to be attached to the frame 3 of the machine.
It can also be easily removed.

The side plates 44 , 45 are spaced apart and rigid in parallel to support the rolls 40 , 41 , 42 and all other structures that make up the belt assembly 21 by the internal structural plate 32 and the shaft 43 . Supported.

The end of the shaft 43 is fixed to the inner race of the bearing 46,47.

The side plates 44 and 45 are also supported by the shaft 63 at a distance from each other.

This shaft 63 is the same as the hollow rotating shaft 43 except that it is fixed to the side plates 44, 45 and does not rotate.

This shaft 63 is chamfered 64 at its end near the frame plate 45 so as to engage a conical portion 65 of the support shaft 24 which is axially aligned with the hollow shaft 63.

The shaft 24 is fixed to the frame plate 48 and has a threaded portion 87 formed at its outer end, into which a locking member 68 is screwed.

Tackle member 68 is formed with an inwardly tapered or conical portion 69 that engages an inner beveled surface 70 formed on the outer end of hollow shaft 63.

Knob 71 of locking member 68 allows manual locking of inner shaft 24 within intermediate shaft 63.

From the above explanation, the belt assembly 21 has a hollow shaft 43.
63G Therefore, it is attached to the frame support plate 48 in a cantilevered state, and the tapered part, that is, the conical part 51° 57 is used for the shaft 43, and the shaft 63
It will be appreciated that by using the conical portions 65 and 69, the belt assembly 21 can be precisely positioned at the desired location after it has been moved from the frame plate 48.

It will be appreciated that this construction allows for quick and easy replacement and removal of belt assemblies on the frame, while also allowing belt drive means to be installed and belt 20 to be removed from its support assembly 21.

When the belt assembly 21 is displaced in the lateral force direction while moving around the rolls 40 and 4L42,
A device is provided to correct the trajectory of the

The apparatus includes a roll mount for rocking motion and an edge guide device associated with roll 40 to effect rocking motion of the roll in response to lateral movement of the belt.

No. 102,312 (1,9
(filed on December 27, 1970).

As shown in FIGS. 2 and 3, the roll 41 is connected to the yaw 7 member 78.
Parallel legs γ6. The end of the TI is fixed to a shaft T5 which is supported in a fixed bearing.

An intermediate position of the yoke member extending in the opposite direction to the leg portions 76 and 77 (this supports the yoke member 78 against rocking movement within a certain limit around the axis of this shaft and allows it to contract slightly). A shaft 80 is attached for the purpose.

This shaft 80 is rotatable (preferably in the shape of a relatively large-diameter cylinder 81 supported by two bearings 82 mounted on the frame 62 at regular intervals, and the lower end of this cylinder 81 is supported by a relatively large diameter cylinder 81). A small diameter portion 83 coaxial with the yaw outer member 78 is fixed to the yaw outer member 78.
It is fixed in a suitable opening formed in the bent part of.

A relatively large coil spring 84 is attached around the shaft 80 between the yoke member γ8 and the lower surface of the lower bearing 82.

The swinging movement of the yoke member 78 about the axis of the cylinder shaft 80 causes the cylinder 81 to rotate within the bearing 82 .

The spring 84 applies an outward force to the yoke 78 and thus the roll 41 so that the belt 20 is attached to the support roll.
``The belt is placed under slight tension during operation.

The roll 41 is attached to the belt assembly 21 for easy installation and removal of the belt 20.
Means is provided for shrinking it inwardly.

To this end, the inner end of the cylinder 81 is coupled to a quick-acting toggle device O which pulls the cylinder inward, and the roll 41 is brought back with it to the retracted position.

This toggle device serves to retain yoke member 78 and roll 41 within belt assembly 14.

The upper portion of cylinder shaft 81 is formed with a tubular extension 91 axially aligned therewith.

Sleeve 91 has suitable openings at both diametrical ends thereof for supporting pins 92 for pivotally connecting one end of link 93 to this end of cylinder 81.

The other end of the link 93 is pivotally connected to one end of another link 94, the other end of which is attached to the frame structure 62.
One pivot is attached.

These links 93,94 and their respective connections form a toggle device which, when driven in linear alignment, moves the cylinder 81 in a downward direction, and when it is in flexion, the cylinder 81 is retracted inwardly. It's understandable that you would.

Said actuation of the toggle link is effected by a drive link 95 which is pivotally connected at one end to the pivot joint between the two links 93,94.

The drive link 95 extends across the belt assembly and through the outer wall surface 44 to a pivot bundle 96 that allows the link 95 to
The toggles 93, 94 are driven into one of two operating states.

When removing or replacing belt 20, bundle 96
Bend the toggle links 93 and 94 by appropriately operating the
Thereby, the cylinder 81 is pulled back inward and the roll 41 is moved backward.

This loosens the belt and allows the operator to easily move it relative to the belt rolls 40, 41, 42.

After installing the belt on the roll, roll 41 is moved by manually manipulating bundle 96 in the opposite direction to bring links 93,94 into their alignment as shown in FIG. Press against the belt 20 to lock the roll in that position.

During this operation, spring 84 acts as an overloading means for the belt as well as a tensioning means as already mentioned.

Mounted within the belt assembly module 21 is an electrode arrangement constituted by the electrical connections of the light guide t-belt 20 and the wiring connected to the power supply and control circuits of the machine.

A belt 20 is placed on each belt support roll 40, 41° 42.
The belt is coated with a thin material such as rubber in order to easily drive the belt and to prevent potential loss of the electrostatic layer image on the belt, that is, charge leakage.

The electrode arrangement described above includes a brush 100 having metal bristles, preferably made of stainless steel, in brush contact with the electrical conductors of the belt 20.

This brush 100 has a frame due to the bracket 101.
It is insulatively fixed to the frame structure and electrically connected by electrical wire 102 to an insulating coupling post 103 fixed to the outer surface of the side support plate 445 of the belt module.

The side plate 45 has an opening for drawing out the outer wire of the electric wire 102 and its attachment portion to the outside of the belt module.

The coupling post 103 is electrically connected to an elongated electrically conductive bar 105 affixed to an insulating material 106, said insulator 106 being affixed to the side support plate 45.

A rod 105 is electrically connected to a curved electrode element 107 fixed to a support plate 110 attached to the frame 9 of the machine via an insulating block 108.

The curved element 107 is connected via a conductor 111 to an electric wire 112 forming part of the control and logic circuit of the machine.

Mechanical and logic circuits are not shown in the drawings because they can take a variety of shapes and are complex.

The role of the metal brush 100, the electric wire 102, the rod 105, the curved element 10T1, the electric wire 111, and the lead wire 112 is to electrically connect the conductor part that is integral with the photoconductive belt 20 to the control circuit of the machine.

Detachable belt assembly (in addition to the power supply, the hose 11
Reduced air or vacuum power is also supplied via 4.

As shown in FIG. 2, the belt assembly is configured to have three belt running surfaces, ie, a flat surface of the belt.

In order to provide a running surface that is accurate and flat and allows the belt running surface to be positioned on the correct flat surface without vibration or undesirable displacement and always occupy the operating position, each running surface [ In this case, the belt assembly is provided with a flattening and holding device.

For this purpose, a holding device 125 is provided on the exposed running surface, that is, the running surface between the rolls 40.41, a holding device 126 is provided on the developing running surface between the rolls 41.42, and a holding device 126 is provided on the exposed running surface, that is, the running surface between the rolls 40.41.
A holding device 127 is provided on the cleaning running surface between.

Since each holding device is identical except for differences in size, only the developing holding device 126 will be described below.

5. As shown in FIG. be done.

The surface of the plenum opposite bell 1-20 is formed with a plurality of ribs 138 projecting from and integral with the surface.

Along this rib, all the openings 132 are connected to the outer ends of all the ribs 133 on the same side of the flat plate 131.
An outer circumferential guard wall 134 surrounding the is similarly integrally formed.

Flat plate 13 in the space between each rib 133 and outer peripheral wall 134
One side surface is sealed by a manifold 135 made of readable plastic material.

A flat web portion 136 of the manifold 135 extends across all ribs and the outer circumferential wall 134.

The direction of the flat plate 131 is marked on the outer peripheral edge of the manifold 135.
At this time, the outer peripheral wall 134 is completely (surrounded by the wall surface 13
7 is formed.

This wall surface 137 can be properly tightened by using a washer 140 on the plate 1.
31 terminates at a flange 138 which is secured to the surface of 31.

This flange 1 is used to vacuum-seal the internal chamber regulated by the flat surface 136 of the manifold 135 and the plate 131.
A peripheral gasket or seal 140 is inserted between 38 and plate 131.

The manifold 135 includes a chamber 142 made of the same material as the web section 136, the end of which is a hose coupler 143 to which the hose of the air exhaust system is connected.

The wall surface 142 of this chamber 142 spans the entire space between each rib 133 so that the web portion 1 at approximately the center of the plate 131
It extends over 36 planes.

As shown in FIG. 6, this chamber communicates with all the spaces between all the ribs 133.

The length of the ribs is shortened so as not to reach the central core part 144 of the vertical and horizontal ribs as shown in Figure 6.

In order to improve the vacuum effect of the holding device 126, the plate 13
A groove 146 with a semicircular cross section is provided on the side that supports the belt 20 of No. 1.
are formed, the grooves communicating with some of the outermost openings 132 and terminating near the outer ends of plate 131.

Since air is exhausted from the space defined by the outer peripheral wall 134 surrounding the outermost row of openings 132, the vacuum force generated by exhausting the air is transmitted along the groove 146 to its most extreme end.

As shown in FIG. 5, when the belt is placed on the plenum plate 131 and a vacuum force is applied to the plenum from a vacuum source, the belt is pressed against the plate due to the pressure difference generated in the space on both sides of the plate 131. Ru.

This vacuum force applied to the belt is applied from the outer end of the groove row 146 at one end of the plate 131 to the outer end of the groove row at the opposite end of the plate.

This vacuum force applied to the belt is continued throughout the belt's movement over the belt assembly 14 to flatten the belt and keep it free of ripples when adverse movement occurs on the retainer.

[As you can easily understand, the developing device 2 in the developing area 26
A retaining device 126 facing 7 is fixed to maintain a predetermined distance from the developer and magnetic brush 29 even if belt assembly 21 or housing 27 of the developer is improperly moved.

The vacuum retainer 126 further includes a flexible web 14 extending across the plenum plate 131 for various purposes.
7 is installed.

A belt 1 that traverses this web material and applies force to it.
2 constitutes a photoconductive belt, so this web material 1
47 corresponds to the nonconductor number.

This web material 147 thus electrically insulates the belt from the holding device.

Additionally, this web material, preferably made of soft fibers or paper, protects the conductor layer of the belt from wear and abrasion, while at the same time reducing friction between the moving belt and plate 131 and reducing openings 32. It prevents your poetic talent from being inhibited by garbage.

Web 147 is held on the outer surface of plenum plate 131 by a pair of parallel rods 150, 151 secured to each end thereof.

Each rod is held rigidly under the outer end of the plenum plate.

As shown in FIG. 6, one end of the web 142 is wrapped around a rod 150 several times, and the other end is wrapped around a rod 151 several times.

It is bent around the outer edge of the plate 131 in the bent state.

Below the edge 152 of the plate, the rod 150 is connected to the plenum 131.
It is rotatably supported within a pair of alignment bosses 154 (one of which is shown in FIG. 5) arranged at both ends of the .

Since the rods 150 and 151 and their associated structures are identical, only the rod 150 and its attached structure will be described in detail.

This rod 150 passes through and is slidably supported by a boss 154, and one of its outer ends is secured to a knob 155 having serrations 156 formed on one side.

The serrations are capable of interlocking with corresponding serrations formed on the outer surface of the boss 154, and when they engage, the knob and rod 150 are prevented from rotating.

A coil spring 157 that presses the knob against the boss in order to interlock the sawtooth portions of the two is connected to the rod 150 [pin 158 which is attached to the inner surface of the boss and fixed to the rod].
It is supported with light pressure applied between it.

(Thus, when tensioning and expanding the web material as needed, the operator simply pulls the knob 155 over the spring 1.
Pull against the pressing force of 57 to disengage the saw teeth,
The web material may be wound onto the rod 150 by rotating the knob in the desired direction.

The rod 151 is similarly provided with a web clamping device associated therewith.

To remove the web material, simply rotate the rod 150 and unwind the attached web material.

Each rod 150, 1511 is provided with a suitable web clamp for securing the end of the web material and wrapping it onto each rod.

The vacuum retainer 126 is generally attached to the frame 62 of the belt assembly to limit movement in a direction perpendicular to the belt 20.
is elastically supported.

Although the amount is limited, the holding device 126 can be moved, so that the bevert module 21 and/or the developing device 2 can be moved.
It is clear that even if 7 should be displaced, it can be automatically compensated for.

Referring to FIGS. 5 and 8, mounting openings 200 are provided outside the track of belt 20 at each corner of retainer 126. Referring to FIGS.

An opposing opening 201 is formed in the frame member 62 of the belt module as an internally threaded opening.

The frame member 62 is attached to the lower part 205 of the bolt 204.
is threaded and serves to detachably hold the vacuum holding device 126 on the belt module 21.

A stop surface constituted by the large diameter bolt head 206 limits the outward movement of the retaining device 126 away from the belt module 21 and also
1 and the joint surface of the frame member 62 of the belt module.
6 in the inner direction, that is, the movement toward the belt module 21 is restricted.

A spring 2 is provided between the base 131 of the vacuum holder 126 and the frame member 62 of the belt module 21 to hold the vacuum holder in a desired operating position in contact with the underside of the belt 20.
08 is installed.

Developer unit 127 includes a suitable outer housing 220 within which a plurality of magnetic brushes 29 are rotatably supported.

Furthermore, the lower part 221 of this housing 220 constitutes a receptacle for the developer mixture.

A developer housing 222, supported near the top of the developer housing 220, communicates with the exterior of the development apparatus for supplying fresh developer.

Details of this developing device [U.S. Patent No. 3,967]
, No. 050 (published October 12, 1972).

The housing 220 of the developing device 21 has a journal shaft 230
It is pivotally supported on its underside by.

This shaft 230 is rotatably supported on the bottom pan section of the machine frame by an upright strap 231.

With the above structure, the entire developing device 21 is equipped with the magnetic brush 2.
The developer assembly including 9 can be pivoted downwardly about the axis of journal shaft 230 away from belt 20 .

This allows the belt module 21 to operate and the developing device 2 to operate.
7 can be easily removed and installed.

In order to place the developer unit 27 in an operating position opposite the belt 20 and the vacuum retainer 126, a manually operated cam 235 is supported on the base pan 9' of the machine frame, and this cam 235 is connected to the housing. 220 flange 22
0', and when it rotates, it rubs the housing 220 parallel to the belt 20.

When the cam 235 is released, the developing device 27 separates from the belt 20 and belt module 21 due to gravity.

As will be readily understood by those skilled in the art, the spacing between magnetic brush 29 and the surface of belt 20 is critical to developing an even and optimal image on belt 20.

To achieve this, a developing device 27 is installed on the underside of the developer housing 220, along with a belt 20 and a vacuum holding device 1.
When moved to the operating position opposite to 26 [this base 1
31 is provided.

This stopper 241 is sized to form a necessary and precise gap between the magnetic brush 29 of the developing device and the belt 20.

Stop 241 is preferably adjustable so that it can be threadedly engaged with developer housing 220 to allow relative movement therebetween.

As can be seen from the foregoing description, the vacuum retainer 126 is mounted against a base biased by a spring 208 in order to accommodate unexpected movements or displacements of the belt module 21 that often occur during machine installation and/or use. It is arranged so that it can be displaced within a certain limit.

Further, since the developing device 27 itself is placed in contact with the floating holding device 126, any non-traction movement of the developing device or the structure supporting it is absorbed by the displacement of the holding device 126.

At this time, the correct gap between the magnetic brush 29 and the belt 20 is maintained during the above displacement.

Referring to FIG. 1.8.9, there is provided a device for the copier service person or operator to determine whether the developer device 27 is in the correct operating position relative to the belt 20 and the retention device 126. It is shown.

In this embodiment, the positioning stops 241 serve as switch contacts so that when each positioning stop 241 engages with the base 131 of the holding device 126, the associated signal light 250 lights up.

The light 250 is preferably mounted on a panel 251 of the copier housing.

Figure 9 conceptually shows the batch IJ-253.
A suitable power source indicated by is provided for each light 250 and its switch, e.g. stopper 24.
1 and base 131 are coupled to parallel circuit 254 .

In this case, each lead wire is guided to each positioning stop 241, while the base 131 of the holding device 126 is connected to the batch 'J-253 via the bolt 204, the frame 62 of the belt module, the brush 100 and the electric wire 115.
is connected to the ground side of the

In this way, the developing device 27 is positioned at the correct position when all the lamps 250 are lit.

The failure of one or more of the lamps 250 to illuminate indicates that the developer device 220 is not properly positioned in the retainer 126 and may cause improper development by the magnetic brush 29. There is.

Although the present invention has been described above with reference to the illustrated structure, the present invention is not limited to these structures, and includes modifications and improvements that can be made within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of one embodiment of an electrostatographic copying machine according to the present invention showing the various operating stations. FIG. 2 is a partial sectional view of the photoelectric belt module of the copying machine shown in FIG. 1. FIG. 3 is a partial cross-sectional view of the belt module shown in FIG. 2 showing details of the module mounting apparatus and belt tensioning means; FIG. 4 is a partial cross-sectional view of the belt module of FIG. 2 showing the electrical and vacuum coupling devices between the module and the copier. FIG. 5 is a partially cutaway plan view of the vacuum holding plate. Figure 6 shows a certain holding plate in the non-operating state.
6-line cross-sectional view. FIG. 1 is a view similar to FIG. 6 showing the retaining plate in the activated state; FIG. 8 is a partial sectional view showing details of the holding plate and the developer device mounting device. FIG. 9 is an electrical schematic diagram of the signal circuit. Reference number, 10
... Electrostatic copying machine, 12 ... Original picture, 19
...Optical system, 21...Belt assembly,
20...Belt, 23, 24...Shaft, 25...Exposure station, 26...
...Development station, 27...Development device,
29...Magnetic brush, 30...Transfer station, 32...Copy paper, 35...
・Sheet conveyance mechanism, 37... Fixing device, 40,
41.42...Roll, 125,126,12
7. River... Holding device, 131... Platen, 2
41...Positioning stopper, 250...
...Signal light.

Claims (1)

Claims: 1. A flexible web having a photoconductive surface for forming and developing an electrostatic latent image of an original to be reproduced, and an internal frame member supporting and supporting said web in an endless path of travel. a plurality of support rolls for the web rotatably mounted on the frame member, the support rolls having a substantially planar surface facing the web and disposed between a pair of the rolls; a platen for said web; web support means including means for applying tension to said web to draw said web toward said platen to provide a substantially flat running surface during development of an image on said web; a platen for moving the platen relative to it when the frame member is unduly displaced to limit relative movement relative to the frame member to maintain an operative connection between the platen and the web; and biasing means for elastically pressing the platen against the web. The developing means includes a developer housing, and the developer housing is disposed opposite to the platen so that the movement of the platen is interlocked with the developer housing. Copying machine mentioned.