JPH02117539A - Original conveyor - Google Patents

Abstract

PURPOSE:To regulate the contact pressure of a reversely conveyed original with an abut plate to a specified value by providing a conveying roller which separates the conveying roller, except original conveying roller distributed to at least the one approaching the abut plate of a plurality of shafts, of original conveying rollers when an original is reversely conveyed toward the abut plate. CONSTITUTION:Through rotation of cams 373A and 373B to a bottom dead center position, swing levers 377A and 377B are swung around support axles 375A and 375B through press of them by means of the cams 373A and 373B, respectively. Since the tip part of each lever presses and pushes up bearings 342A and 342B engaged with ends across the shaft of a conveyor roller 302, the conveying roller 302 is separated away from the surface of a platen glass. Swing levers 377C and 377D are also swung and a conveyor roller 303 is also separated away from the surface of the platen glass. However, since a first conveying roller effects rotational drive in a state to be pressed against the glass, during conveying of an original, the original is conveyed in a state to be brought into a pressure contact only by the conveying roller despite the size of the original.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention “automatically feeds a document onto the document table (platen glass) of a copying machine, image reading device, etc. This invention relates to an improvement in a document conveying device that ejects documents from a table.

[Conventional technology]

Generally, this type of document feeder includes a document storage section (paper feed tray) disposed on the side of the document table, and a document feeder that feeds the document sheet by sheet from the paper feed tray toward the document table. a feeding means, which is disposed on the document table, conveys the document fed from the document feeding device, and fixes the document at an exposure position on the document table surface, and when exposure of a predetermined number of sheets is completed, the document is transferred to the document table; It is composed of a document conveying means for discharging the document from the table, and a paper discharge means for collecting the exposed document and placing it on the paper discharge tray.

This document conveying device preferably includes a document conveying means on the platen glass of a copying machine, which presses the document against the platen glass surface using a white endless belt, and conveys the document by the movement of the belt.

That is, this document conveying means covers the entire surface of the platen glass with an endless belt and presses the document, and conveys the document while generating frictional force with appropriate places on the surface of the document due to slight slack in the endless belt. For this reason, (1) a sufficient space in the thickness direction for the belt to rotate was required, and the overall height of the device body increased, resulting in an increase in size;

■The pressing force decreases over time due to fatigue and deterioration of the belt, and troubles due to lack of elasticity tend to occur, resulting in poor maintainability.

■A large, high-output motor must be used to rotate the belt while sliding it on the platen glass.

It had problems such as.

The present applicant has previously proposed an original document conveying device that improves the above-mentioned problems and can simultaneously reduce the thickness of the device and improve maintainability (Japanese Patent Application No. 63-3341).

The document conveying device of the present invention is provided with a document holding sheet member (white fixed sheet member, hereinafter referred to as sheet member) along the platen glass surface in the device main body disposed on a copying machine, and provided at an appropriate position on the sheet member. A document conveyance roller is brought into sliding contact with the platen glass surface through a through hole, so that the height of the entire apparatus can be reduced and the document can be conveyed without using an endless belt.

The document conveyance rollers of the document conveyance device are composed of a plurality of roller groups for conveying documents of various sizes on the platen glass, and each roller receives rotational force from a drive source.

In this document conveying device, the document is sequentially carried in between the platen glass surface and the document holding sheet in the conveying section, and then the document is reversely conveyed to hit the document trailing end stopper plate (abutment plate). The document is positioned and stopped in this abutting and stopped state, and the document in this abutting and stopped state is exposed.

FIG. 12 is a plan view showing the document size and the arrangement of conveyance rollers. In the figure, the document table (platen glass) 11
Documents of various sizes are stopped on the abutment plate 12 at the left end of the document and undergo exposure processing. On the upper surface side of the document table 11, document conveying rollers 301, 302, 303 of a document conveying device and a white sheet member 304 are provided.

[Problem that the invention seeks to solve]

However, in such a document conveying device, when a document is conveyed on the document table 11 toward the abutment plate 12, in the case of a minimum size 9 document, such as an 86-size or 85-size document, the abutment plate 12 L-axis document transport roller 30 close to
1, the original is conveyed under pressure, and the maximum size original,
For example, in the case of an A3 size document, the document is slid and conveyed by the document conveyance rollers 301, 302, and 303 of multiple axes.

In this way, documents of various sizes that are abutted against the abutment plate 12 are sent only by the sliding conveyance force of the l-axis document conveyance roller 301 in the case of small-sized documents; The pressing force is small, and for medium-sized documents, two-axis document conveyance rollers 301 and 302 are used, and for large-size documents, three-axis document conveyance rollers 301 and 1 are used.
．． 302 and 303, the abutting plate 12 for medium-sized and large-sized originals
The abutment force increases in proportion to the number of axes.

When the document is reversely fed and brought into contact with and stopped by the abutment plate 12, if the force with which the document is abutted against the document by each document transport roller is excessive, the rear edge of the document may be bent or wrinkles may occur in the document. Or the original is placed askew. Alternatively, troubles may occur, such as the rear end of the document riding on the top surface of the abutment plate 12, or the document slipping over the top of the abutment plate 12 and returning to the paper feed section.

[Means for solving problems]

In view of the above-mentioned points, the present invention improves a document conveyance device comprising the document holding sheet member and a rotationally driven document conveyance roller, which can achieve both reduction in thickness and improvement in maintainability.
It is an object of the present invention to provide a document conveying device in which reversely conveyed documents of various sizes can uniformly abut against an abutment plate, stop reliably, and accurately position documents.

In order to achieve the above object, the document conveying device of the present invention forwardly conveys the document fed from the paper feeding means on the document table of the copying machine, and reverses the document so as to abut it against the abutment plate. In a document conveyance device consisting of a forward-reversible document conveyance roller that conveys the document in one direction and a document holding sheet member that presses the document against the document table surface, a plurality of document conveyance rollers distributed over a plurality of axes that press the document table surface are Among the document conveying rollers, when the document is arranged in a column along the conveying direction and conveying the document in the reverse direction toward the abutting plate,
The present invention is characterized in that means is provided for separating conveyance rollers other than the document conveyance roller distributed on at least one of the plurality of axes adjacent to the abutment plate from the document table surface.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of the document conveying device according to the present invention, FIG. 2 is a drive system diagram of the entire document conveying device, FIG. 3 is a plan view of the conveyance roller drive system, and FIG. 4 is a perspective view of the conveyance section. .

In these figures, IO is the main body of the copying machine, 11 is a platen glass, 12 is a document rear end stopper plate (abutment plate), and the document conveyance device 100 is mounted above the platen glass 11. The document conveyance device 100 is attached to a hinge portion at the top of the copying machine main body 1O and has a swingable structure, so that the top surface of the platen glass 11 can be opened and closed.

The document conveying device 100 includes a paper feeding section 200, a conveying section 300,
The paper discharge section 400 is composed of three main parts.

The document conveyance device 100 has a paper feed tray slanted at the top, which is composed of a foldable movable paper tray 102 and a fixed paper feed tray 103 fixed to the housing body 101. Original sheets can be placed in a stacked manner on the tray, and the leading edge of the original sheet is inserted into the paper feed section 200.
It has become. Further, 104 is a paper width regulating plate for regulating the width of the document.

The stationary paper feed tray 103 has a concave cutout near the center on the downstream side in the paper feed direction, and a movable guide plate 105 is installed in the concave cutout so that it can swing vertically from the top surface of the fixed paper feed tray 103. It's free. The movable guide plate! 05 is connected to a solenoid (not shown).

On the other hand, above the movable guide plate 105, a delivery lever is swingably supported. That is, one end of the shaft of the feed lever 201 is rotatably supported above the paper feed port 106 of the housing body 101, and the other end is lowered by the weight of the feed lever 201 to press against the upper surface of the document tray.

When feeding a document, the movable guide plate 105 is in the raised position and is stopped slightly above the upper surface of the outer periphery of the feed roller 212. In this state, when a document tray is set on the movable ring paper tray 102 and the fixed paper feed tray 103 and the document tray is pushed forward in the paper feeding direction, the tip of the document tray will move along the upper surface of the movable guide plate 105. As it is pushed out, the lower surface of the feed lever 2, which is supported upward and hangs down by its own weight, is pushed up and comes into contact with the outer peripheral surface of a double feed prevention roller 213 and a rib of the housing body 101, which will be described later, and is stopped.

FIG. 1 is a sectional view showing this document set state.

When the solenoid is energized in response to a paper feed start signal, the movable guide plate 105 is swung and its leading end is lowered and submerged from the upper surface of the fixed paper feed tray 103.

Next, a paper feed unit 200 provided on the left side of the document feeder 100 on the downstream side of the paper feed tray feeds the stack of originals inserted from above the paper feed tray, and then feeds the stack of originals inserted from the top of the paper feed tray, and then It is provided with a sending means (first paper feeding means) for separating and sending out the documents one by one, and a second paper feeding means for feeding the separated documents onto the platen glass If of the copying machine main body IO.

This feeding means includes a feeding roller (first paper feeding roller) 212 loosely fitted into the center of the first drive shaft 210 and driven by the second driving shaft 211;
A double-feed prevention roller 213 is pivotally supported by a double-feed prevention roller mounting plate 214 provided diagonally above the double-feed prevention roller.

FIG. 2 is a drive system diagram of the entire document conveying device.

The drive shaft of the Meizo motor 215 is gear 2ta, 217
, timing pulley '218,219 and timing belt 2'20.

The gear 2211 coaxial with the timing pulley 219
Rotate the drive shaft 211. 'A gear 22 with a built-in one-way clutch 223 is provided at one shaft end of the second drive shaft 211.
It has 4. This gear 224 is the first drive m2t
It meshes with the gear 225 without being integral with the feed-out roller 212 which is loosely fitted into the gear 225. That is, with respect to the main motor 215 which rotates forward and backward, the feed roller 212 loosely fitted to the Ml drive shaft 210 is rotated by power transmission from the second drive shaft 211 only when the main motor 215 rotates in the reverse direction.
When the main motor 215 rotates in the normal direction, power is not transmitted and the main motor 215 rotates freely.

On the other hand, on the axis of the second drive shaft 211, second paper feed rollers 226 and 2 are provided on both sides of the feed roller 212, respectively.
26 is fixed to the shaft and rotates together with the drive shaft.

Further, near the shaft end of the first drive shaft 210, two gears 227 and 228 having a built-in directional clutch and a shaft-locked gear 229 are respectively attached.

On the other hand, a gear 230 is fixed to the shaft end of the second drive shaft 211, and the gear 230 meshes with a gear 227 at the shaft end of the first drive shaft 210 via an idler gear 231.

Thus, the first drive shaft 210 and the second paper feed rollers 226 and 226 integral therewith have the function of constantly rotating in the paper feeding direction in response to the forward and reverse rotations of the main motor 215.

A gear 229 fixed to the first drive shaft 210 is connected via an idler gear 232 to a third drive shaft (torque limiter shaft) 234 having a gear 233 fixed to one shaft end.
power is transmitted to. A gear 236 having a torque limiter 235 is provided at the other shaft end of the third drive shaft 234 . The gear 236 meshes with a gear 238 which is integral with the double feed prevention roller 213 via an idler gear 237. The double feed prevention roller 213 is pressed against the feed roller 212 with a predetermined pressure to form a nip.

As described above, the first drive shaft 210 rotates in one direction regardless of whether the main motor 215 rotates in the forward or reverse direction, and the double-feed prevention roller 213 coupled to the first drive shaft 210 through gears can also rotate in one direction.

A second paper feed roller 226 is fixed to the first drive shaft 210 that loosely fits and supports the feed roller 212 during document feeding by the feed roller 212 and double feeding prevention roller 213.
．． The feed roller 226 also rotates at the same speed and in the same direction as the feed roller 212, and plays an auxiliary role in feeding the document in a U-turn.

The second paper feeding means of the paper feeding means 200 is connected to the first drive shaft 21.
It consists of two second feed rollers 226, 226 fixed to both sides of the feed roller 212 which is loosely fitted into the feed roller 212, and a driven roller 240 which is pressed against the lower surface of the rollers 226, 226 so as to be rotatable. There is.

The second paper feed rollers 226, 226 can be driven independently of the feed roller 212, and
2 rotates in the same direction so as not to interfere with the feeding of the original document.

The driven roller 2
A document detection sensor 241 is provided near the pressure contact position 40 . The document detection sensor 241 turns ON when the leading edge of one document separated and sent out at the nip position among the document bundle passes, and turns ON when the trailing edge of the document passes.
It is designed to be FF.

When the document detection sensor 241 detects the leading edge of the document, the solenoid is turned off after a certain period of time after generating the detection signal.
N to operate each member of the link mechanism and lower the movable guide plate 105.

At the same time, the main motor 215 shifts from reverse rotation to forward rotation; (No rotation is transmitted to the gear 228 that incorporates a directional clutch), the first drive shaft 210 continues to rotate in the same direction, and the second paper feed roller 226 fixed to the shaft 210 also continues to rotate in the same direction. Rotate.

However, as the main motor 215 shifts to forward rotation, the second drive shaft 211 also shifts from reverse rotation to forward rotation. Then, the rotation is no longer transmitted to the gear 225 that meshes with the gear 225 and the delivery roller 212 that is integral with the gear 225.

Here, when the leading edge of the document is pressed and held between the second paper feed roller 226 and the driven roller 240, the feed roller 212 rotates freely and the second paper feed roller 226 rotates forward.
The document paper tightly wound around the paper feed roller 212 is driven to rotate in the paper feeding direction.

Note that since the first drive shaft 210 continues to rotate in the normal direction, the double-feed prevention roller 213 continues to rotate in the normal direction to prevent double feeding of the second and subsequent documents and return them. Further, the second paper feed roller 226 continues to rotate after that, and the separated paper feed roller 226 continues to rotate.
The original sheets are successively fed to the transport section 300.

The conveyance unit 300 is for conveying a document on the platen glass U, and includes document conveyance rollers 301, 302, and 303 that press the document and forward and reverse the document, and a drive that drives the conveyance roller in forward and reverse directions. A white original holding sheet member (hereinafter referred to as a sheet member) 304, and a sheet pressing means for pressing and releasing the sheet member 304 are provided as main components.

The document conveying rollers 301, 302, and 303 are for conveying the document on the platen glass 11, and are rotated while pressing the document and conveys the document using frictional force. They are provided to correspond to the holes 305, 306, and 307. Said roller 301.302.30
The surface of 305.3 is covered with an elastic material having a large frictional force (for example, a rubber or glass sponge body), and the through hole 305.
The end portions are in contact with the surface of the platen glass 11 through 306 and 307. In addition, the document transport rollers 301 and 302
, 303 are capable of forward and reverse rotation so that the final position of the document tray can be finely adjusted during exposure.

The main motor 215 is connected to the paper feed section 200 and the conveyance section 3.
00 is driven at the same time. That is, the drive rotational force of the main motor 215 is transmitted through the gear trains 216, 321, 320, and 316 to rotate the drive shaft 311.

FIG. 5 is a sectional view of the conveyance drive section 310.

The drive shaft 311 has bearings 312 and 313 degrees near both ends of the shaft, and a mounting plate 314 that fixes the bearings 312 and 313.
315, and is rotatably supported by the shaft. Further, a gear 316 is fixed to one shaft end of the drive shaft 311, and a timing pulley 317 is fixed to the vicinity of the other shaft end. The gear 3
16 meshes with a small-diameter gear 320 that is rotatable on an idler shaft 319 fixed to a mounting plate 318. The small diameter gear 320 is integrated with the large diameter gear 321, and the gear 321
is a gear 2 that is integrated with the drive shaft of the main motor 215.
It meshes with 16.

In this way, the driving rotational force of the main motor 215 is transmitted to the gear train 21.
6.321.320.316, and the drive shaft 3
Rotate 11.

A timing pulley 317 fixed to the shaft end of the drive shaft 311
has toothed pulleys at two locations on both ends, and can be rotated by winding timing belts 322 and 323 respectively.

A first conveyance roller section 330 is disposed on the feeding upstream side of the driving conveyance section 310 with a timing belt 322 interposed therebetween. In addition, a timing belt 323 is provided on the downstream side of the feed.
A second conveyance roller section 340 is disposed via the timing belt 324, and a third conveyance roller 5350 is disposed further downstream on the feeding side via the timing belt 324.

FIG. 6 is a sectional view of the first conveyance roller section 330. Note that since the above-mentioned conveyance rollers 330, 340, and 350 are all composed of a common member, the conveyance roller section 330 of the cylinder 1 will be explained below as a representative.

A timing pulley 331 is fixed to the center of a rotating shaft 301a that is integral with the document transport roller 301. Further, bearings 332A and 332B made of a steel-based sintered alloy are fitted to both ends of the rotating shaft 301a.

The bearings 332A and 332B are inserted into vertically elongated holes in the front and rear conveyor roller mounting plates 333, respectively, and are prevented from rotating at the notches. Rotating shaft 301 of the document transport roller 301
a is the mounting plate 3 along with the bearings 332A and 332B.
33 is inserted. The bearings 332A and 332B are biased by springs and press the outer peripheral surface of the document conveying roller 301 against the surface of the platen glass 11.

The first conveyance roller section 330 configured in this way is pressed against the platen glass 11 and is also pressed against the timing belt 32 wound around the timing pulleys 317 and 331.
Drive is transmitted by 2.

The document conveyance roller 302 of the second conveyance roller section 340 is similarly biased by the spring, and the timing belt 3
23 rotates the timing pulley 341 and the rotation is transmitted.

Here, 342A and 342B are bearings that rotatably support the shaft portions at both ends of the conveyance roller 303, and are fitted into the mounting plate 343 to be movable in the vertical direction, and are pressurized against the platen glass 11 side by the torsion spring 344 has been done.

The document transport roller 303 of the third transport roller section 350 is
The above timing pulley 341 and timing belt 324
The timing pulley 351 receives the driving force of the timing pulley 351, and is rotated together with the timing pulley 351. The spring biasing force also presses the conveyance roller in the same manner as described above to move the platen glass 11.
Apply pressure to the side. Here, 352A and 352B are bearings that rotatably support the shaft portions at both ends of the conveyance roller 302. The bearings 352A and 352B rotatably support the shaft portions at both ends of the conveyance roller 302. The bearings 352A and 352B are fitted into the long length of the mounting plate 353 and are movable in the vertical direction.
Pressure is applied to the side.

FIG. 7 shows the conveyance rollers 302 and 303 showing the document conveyance state.
FIG. 8 is a side view of the rotation driving means of the transport roller 302.
．． 303 is a side view of the elevating drive means of FIG.

A timing pulley 361 is integrally formed on the shaft of the gears 320 and 321, and a timing belt 36
2, the timing pulley 363 is wound around the other timing pulley 363. The timing pulley 363 is integrated with a gear 364 and is rotatable about a support shaft 365 on which a support substrate 366 is implanted. The gear 364 is a camshaft 371 which will be described later.
meshes with a gear 3671 in a spring clutch 367 provided at one end of the spring clutch 367; The camshaft 371 is connected to a bearing 368 fixed to the support substrate 366 and a conveyance roller lifting means 370 which will be described later.
It is rotatably supported by bearings 372A and 372B provided on a support plate 374.

FIG. 9 is a perspective view of spring clutch 367.

In the figure, the spring clutch 367 is integrated with a hub 3672 fixed to a camshaft 371 and a sliding bearing 3673 fitted to the camshaft 371, and the gear 367 is rotatable.
1, a coil spring 3674 that is wound around the bodies of the gear 3671 and the hub 3672 and can be tightened and relaxed, and a collar 3675 that locks one end of the coil spring 3674 and covers the coil spring 3674. There is. Above hub 3
A protrusion 3672A is formed on a part of the outer periphery of the hub 3672, and when the protrusion 3672A abuts one tongue portion 369A of the stopper 369 fixed to the support substrate 366, the rotation of the hub 3672 is prevented. will be stopped.

Furthermore, a protrusion 3675 is also provided on a part of the outer periphery of the collar 3675.
A is formed, and when the projection 3675A abuts the other tongue portion 369B of the stop collar 369, the collar 3675 stops rotating.

The camshaft 371 includes eccentric cams 373A, 373.
B is fixed on the shaft.

Four support shafts 375 are provided on the front and rear side walls of the mounting plate 374.
A, 375B, 375G, 375D are installed, and coil springs 376A, 376B, 376G, 3 are installed in each axis.
76D is wrapped. Each shaft also includes swing levers 377A, 377B, and 377C that are integrated with bearings.
, 377D are respectively fitted.

The swing levers 377A, 377B are biased by coil springs 376A, 376B, respectively, and swing counterclockwise about the support shafts 375A, 375B.
The right end (see Figure 8) rises, and the eccentric cam 373A,
373B is pressed against it. - direction swing/< -377A
, the left end of 377B is lowered, and the second conveyance roller section 34
The conveyance roller 302 of 0 is a torsion spring 344
The mounting plate 343 descends along the elongated hole due to the spring urging force and its own weight, and comes into contact with and presses against the upper surface of the platen glass 11.

At the same time, the other swinging levers 377G and 377D are biased by coil springs 376C and 376D, respectively, and swing counterclockwise about the support shafts 375A and 375B. The left end (see Fig. 8) rises, and the eccentric cams 373C, 373D
are pressed together. On the other hand, the swing levers 377C, 377
The right end of D descends, and the conveyance roller 303 of the third conveyance roller section 350 descends along the length of the mounting plate 353 due to the spring urging force of the torsion spring 354 and its own weight, and comes into contact with the upper surface of the platen glass 11. Pressure contact.

When conveying a large-sized document (for example, A3 size, B4 size, etc.), the conveyance rollers 302 and 303 are lowered, press the document on the platen glass 11, drive and rotate, and convey it.

Due to the reverse drive of the main motor 215, the large-sized document fed from the paper feed section 200 toward the platen glass 11 is transported by the conveyance roller 301 of the conveyance section 300 shown in FIG.
．． 302 and 303, the document slides on the platen glass 11, and the rear end of the document plate is a document rear end stopper (abutment plate) 1
Pass 2.

After the trailing edge of the document being fed passes through the document detection sensor 241 and generates a trailing edge detection signal, a predetermined pulse corresponding to the document size is counted.

During this forward feeding of the document, each member of the conveyance roller drive unit rotates in the direction of the arrow shown in FIG. 7 by the driving force of the main motor 215, and the hub 3675 of the spring clutch 367 rotates counterclockwise. The protrusion 3675A is the stopper 369
It comes into contact with the tongue piece 369B and stops.

The hub 3675 of this spring clutch 367 is connected to the camshaft 37
The cams 373A and 373
B stops when it reaches the top dead center shown in FIG.

The conveyance roller drive unit continues to rotate in the direction of the arrow above by the driving force of the main motor 215, and the gear 3671 of the spring clutch 367 also continues to rotate, but due to the loosening of the coil spring 3674 built into the spring clutch 367, It idles on the sliding bearing 3673 and the driving force is transferred to the camshaft 371.
is not transmitted.

When this number of pulses is counted up, the main motor 2
15 is changed from reverse rotation to forward rotation, and conveying rollers 301, 3
02.303, the document tray is set at a predetermined position on the platen glass 11 by reversing and abutting the rear end of the document tray against the abutting plate 12.

FIG. 1θ is a side view of the rotational drive means of the conveying unit 300 in a state where the original is being fed backwards, and FIG.
303 is a side view of the elevating drive means of FIG.

Due to the forward rotation of the main motor 215, each member of the conveyance roller drive unit rotates in the direction of the arrow shown in Figure 1θ, and the gear 3671 of the spring clutch 367 rotates clockwise.
Hub 3 is spring-coupled with this via coil spring 3674.
672 are rotated as one. The protruding portion 3672A of the hub 3672 rotates in the opposite direction and comes into contact with the tongue portion 369A of the stopper 369, thereby stopping the hub 3672.

As a result, the cam shaft 371 that is integral with the hub 3672 also stops after rotating in the reverse direction, and the cams 373A and 373B
This is the bottom dead center position shown in the figure. Note that even after the hub 3672 has stopped, the gear 3671 continues to rotate in reverse by the forward rotation driving force of the main motor 215 due to the loosening of the coil spring 3674.

As the cams 373A and 373B rotate to the bottom dead center position, the swing lever 377A is pressed by the cams 373A and 373B.

377B swings around support shafts 375A and 375B, respectively, and the tips of swing levers 377A and 377B are
Bearings 342A, 3 fitted into both shaft ends of the conveyance roller 302
42B and pushes it upward, the conveyance roller 302 is separated from the surface of the platen glass 11.

At the same time, the swing levers 377C and 377D are also connected to the cam 37.
3A.

373B, the conveyance roller 303 also separates from the surface of the platen glass tt. However, the conveyance roller 301 of the first conveyance roller section 330 is always connected to the platen glass 1.
Since the original is rotated by pressing 1, during this reverse feeding, the original is pressed and transported only by the transport roller 301, regardless of the π document size.

After that, after a predetermined pulse count, the sheet member 30
4 brings the document into pressure contact with the platen glass 11, and then exposure scanning and image forming processing of the document are started in the copying machine main body 10.

After the exposure scan, the document is transferred to the transport rollers 301 and 30.
2. It passes over the platen glass 11 by pressure rotation of 303, is pressed and pinched by paper ejection rollers 4011 and pinch rollers 402 and 403 of the paper ejection unit 400, and is ejected.
It is placed on an external paper discharge tray 406.

Paper discharge sensor 40 provided in the conveyance path of the paper discharge section 400
4, when the leading edge or trailing edge of the document is detected,
The feeding operation for the second and subsequent documents is repeated in the same manner as above.

〔Effect of the invention〕

As described above, the document conveyance device of the present invention realizes a thinner device and improved maintainability.I; It is a roller conveyance type document conveyance device. Of the document transport rollers consisting of books, only the transport roller of at least the l-axis near the abutting plate drives the document to be transported backwards, and the other transport rollers are spaced apart from the platen glass surface, so the document is transported backwards. Regardless of its size, it is always moved smoothly backwards by a constant conveying force. As a result, the pressure force applied when the document being transported in the reverse direction is brought into contact with the abutment plate becomes almost constant, and problems such as damage to the document and poor document positioning are eliminated. Furthermore,
The conveying roller elevating means does not require a dedicated power source, the structure of the conveying section is simple, and it has excellent effects in that lower costs and reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the document conveying device according to the present invention, FIG. 2 is a diagram of the entire drive system of this document conveying device, FIG. 3 is a plan view of the conveying roller drive system, and FIG. 4 is a perspective view of the conveying section. , 5th
The figure is a cross-sectional view of the conveyance drive section, FIG. 6 is a cross-sectional view of the conveyance roller section, FIGS. 7 and 1θ are side views of the conveyance roller drive system, and FIGS. 8 and 11 are side views of the conveyance roller lifting means. FIG. 9 is a perspective view of the spring clutch, and FIG. 12 is a plan view showing the document size and the arrangement of the conveyance rollers. lO...Copier main body 11...Platen glass (original table) 12...Document rear end stopper plate (abutting plate) 100...
・Document transport device 215...main motor 300・
・・Conveyance unit 301, 302, 303 ・・Document conveyance roller 304・
. . . Document holding sheet member (sheet member) 310 . . . Conveyance drive section 330 . . . First conveyance roller section 340 . . . Second conveyance roller section 350 . . . Third conveyance roller section 332A, 332B , 342A, 342B, 3
52A, 352B, 372A. 372B... Bearing 344, 354... Tossian spring 333, 3
43.353.374...Mounting plate 367...Spring clutch 369...Stopper 370...Transport roller lifting means

Claims (1)

[Claims] A document conveying roller that can be forward-reversed, which conveys the document fed from the paper feeding means in the forward direction on the document table of the copying machine, and also conveys the document in the reverse direction so as to abut against the abutting plate; In a document conveyance device comprising a document holding sheet member that presses against the document table surface, a plurality of document conveyance rollers distributed over a plurality of axes that press the document table surface are arranged in tandem along the document conveyance direction, and are attached to the abutting plate. When the document is conveyed in the reverse direction, one of the document conveyance rollers,
1. A document conveyance device, comprising means for separating conveyance rollers other than the document conveyance roller distributed on at least one of the plurality of axes adjacent to the abutting plate from a document table surface.