JP2733606B2 - Document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention automatically feeds a document onto a platen (platen glass) such as a copying machine or an image reading apparatus, and places a processed document on the platen. The present invention relates to an improvement of a document conveying device for discharging documents from a document.

[Conventional technology]

Generally, in this type of document feeder, a document storage unit (feed tray) provided on a side of a document table, and a document feeder for feeding documents one by one from the paper feed tray toward the document table. Feeding means and a document arranged on the document table, for conveying a document fed from the document feeding means, quantifying the exposure position on the document table surface and, when a predetermined number of exposures are completed, the document is converted to the document. It is composed of a document conveying means for discharging the document from the table, and a paper feeding means for collecting the document after the exposure and placing it on a paper feeding tray.

Generally, this type of document feeder includes a document feeder that presses a document against a platen glass surface with a white endless belt on a platen glass of a copying machine and conveys the document by moving the belt. . That is, the document conveying means presses the document by covering the entire surface of the platen glass with the endless belt, and conveys the document while generating a frictional force with an appropriate position on the document surface by a slight slack. For this reason, a sufficient space in the thickness direction is required for the belt to rotate, and the overall height of the apparatus main body is increased and the apparatus is enlarged.

The pressing force decreases with time due to the fatigue and deterioration of the belt, and a trouble due to insufficient elasticity is apt to occur, resulting in poor maintainability.

In order to rotate the belt while sliding it on the platen glass, a large motor with high output must be used.

There was a problem such as.

The present applicant has previously proposed a document feeder capable of improving the above-mentioned problems and realizing both a reduction in thickness of the apparatus and an improvement in maintainability (Japanese Patent Application No. 63-3341).

In the document transport of the present invention, a white sheet member is provided along a platen glass surface in an apparatus main body disposed on a copying machine, and a document transport roller slides on the platen glass surface through a through hole provided at an appropriate position of the sheet member. By contacting the original, the height of the entire apparatus is reduced, and the original can be conveyed without using an endless belt.

The document transport roller of the document transport device is composed of a plurality of rollers for transporting documents of various sizes on a platen glass, and each roller receives a rotational force from a driving source.

[Problems to be solved by the invention]

The document transport device including the paper feed unit, the transport unit, and the paper discharge unit is powered by one drive source, and transports a document in one direction from a paper feed tray to a paper discharge tray. That is, the first one
After the trailing end of the first document is discharged, the serial processing operation in which the leading end of the next second document is sent is performed, so that wasteful processing time is consumed when the document is transported. In order to reduce the loss time, it is possible to shorten the processing time by using a plurality of separately controllable driving sources and partially overlapping the respective operations of feeding, transporting, and discharging. However, it has problems such as cost, space, reliability, and maintainability.
It is difficult to realize.

[Means for solving the problem]

In view of the above, the present invention has improved a document feeder capable of simultaneously realizing a thinner and improved maintainability, shortening a document transfer processing time, increasing the number of documents that can be transferred per minute, and having a structure. It is an object of the present invention to provide a simple, compact, and highly reliable document feeder.

In order to achieve the above object, a document feeder according to the present invention includes: a feeding unit configured to feed a document placed on a paper feed tray one by one toward a platen of a document exposure unit; A document transport unit that transports a document fed from the paper feed unit, and a transport roller that transports the document that has been subjected to the exposure processing in cooperation with the document transport unit and places the document on a discharge tray. In a document transport device having a paper discharge unit to be discharged by the paper feed unit, and one drive source for driving the paper feed unit, the document transport unit, and the paper discharge unit, A one-way clutch for prevention is provided, and when the driving direction of the drive source is switched and the second document is fed from the paper feeding unit while the document is being discharged after the exposure by the discharge roller, the discharge is performed. The paper roller is characterized in that reverse rotation is prevented by the one-way clutch. It is.

〔Example〕

Hereinafter, the present invention will be described with reference to an embodiment shown in the accompanying drawings.

FIG. 1 is a sectional view of a document feeder according to the present invention, and FIG.
FIG. 3 is a drive system diagram of the entire document feeder, and FIG. 3 is a plan view of a paper feed roller and its drive system.

In these figures, 10 is a copying machine main body, 11 is a platen glass, 12 is a document rear end stopper plate (abutment plate),
The document feeder 100 is mounted above the platen glass 11. The document feeder 100 is mounted on a hinge at the upper part of the copying machine main body 10 and has a swingable structure, and the upper surface of the platen glass 11 can be freely opened and closed. The above manuscript is on device 10
Numeral 0 is composed of three main parts: a paper feed unit 200, a transport unit 300, and a paper discharge unit 400.

The document feeder 100 has a foldable movable paper tray 102 and a fixed paper tray 10 fixed to the housing body 101 at the top.
Each of the paper feed trays 3 and 4 is provided at an angle, and the originals D can be placed on the paper feed tray in a stacked manner. The leading end of the original D is inserted into the paper feed unit 200. ing.
A paper width regulating plate 104 for regulating the width of the original D when setting the original D is provided on the fixed paper tray 103 so as to be movable in the width direction.

The vicinity of the center of the fixed paper tray 103 on the downstream side in the paper feeding direction is notched in a concave shape, and a movable guide plate is swingable in the vertical direction from the upper surface of the fixed paper tray 103 in the concave notch. It has become. The movable guide plate 105 is connected to a solenoid (not shown).

On the other hand, above the movable guide plate 105, a delivery lever 201 is swingably supported. That is, the shaft portion at one end of the delivery lever 201 is connected to the paper feed port 10 of the housing body 101.
6 is rotatably supported above, and the other end is
The document D is lowered by its own weight and presses the upper surface of the document D.

When a document is fed, the movable guide plate 105 is at the raised position and stops slightly above the outer peripheral upper surface of the feed roller 212. In this state, the original D is set on the movable paper feed tray 102 and the fixed paper feed tray 103, and the original D is pushed forward in the paper feeding direction.
While being pushed out along the upper surface of 105, it pushes up the lower surface of the delivery lever 201 which is supported above and is suspended by its own weight, and comes into contact with the outer peripheral surface of the double feed prevention roller 213 to be described later and the rib of the housing body 101 and stops. . FIG. 1 is a sectional view showing this original setting state.

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

Next, on the left side of the document feeder 100 (FIG. 1), a sheet feeding unit 200 provided on the downstream side of the sheet feeding tray feeds a bundle of documents D inserted from above the sheet feeding tray. A sending means (first feeding means) for separating and sending one sheet at a time from the lowermost layer and a second feeding means for feeding the separated document D onto the platen glass 11 of the copying machine main body 10 are provided. Have.

This sending means is loosely fitted to the center of the first drive shaft 210,
A feed roller (first feed roller) 212 driven by a second drive shaft 211 and a double feed prevention roller 213 pivotally supported by a double feed prevention roller mounting plate 214 provided diagonally above the feed roller 212. It is configured.

FIG. 2 is a drive system diagram of the entire document feeder. The drive shaft of the main motor 215 is gear 216,217, timing pulley
218,219, timing belt 220, timing pulley 219
Gear 221 coaxial with the second drive shaft 211
, The second drive shaft 211 is rotated. One end of the second drive shaft 211 has a gear 224 having a one-way clutch 223 built-in. The gear 224 is connected to the first drive shaft 210.
Gear gear 225 that is integral with the delivery roller 212 that is loosely fitted to the gear. In other words, the feed roller 212 loosely fitted to the first drive shaft 210 is rotated by the
The power is transmitted from the second drive shaft 211 only when the main motor 215 rotates in the reverse direction, and rotates, but when the main motor 215 rotates forward, the power is not transmitted and the motor rotates freely.

On the other hand, on the axis of the second drive shaft 211, the delivery roller 2
On both sides of 12, second paper feed rollers 226, 226 are fixed to the shaft, respectively, and rotate integrally with the drive shaft.

Near the shaft end of the first drive shaft 210, two gears 227 and 228 with a built-in one-way clutch and a gear 229 fixed to the shaft are mounted, respectively.

On the other hand, a gear 230 is fixed to the shaft end of the second drive shaft 211. 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, 226 integrally formed with the first drive shaft 210 have a function of constantly rotating in the paper feed direction with respect to the forward / reverse rotation of the main motor 215.

The gear 229 fixed to the first drive shaft 210 transmits power via an idler gear 232 to a third drive shaft (torque limiter shaft) 234 having a gear 233 fixed to one shaft end. . At the other shaft end of the third drive shaft 234, a gear 236 having a torque limiter 235 is provided. Gear 236
Meshes with a gear 238 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 at a predetermined pressure to form a nip.

As described above, the first drive shaft 210 is connected to the main motor 2
The double feed prevention roller 213 that rotates in one direction regardless of the forward / reverse rotation of the gear 15 and is gear-coupled thereto can also rotate in one direction.

During the document feeding by the feed roller 212 and the double feed prevention roller 213, the first roller for loosely supporting the feed roller 212 is supported.
The second paper feed rollers 226, 226 fixed to the drive shaft 210 also rotate in the same direction at the same speed as the feed roller 212, and the original D
In the U-turn.

The second paper supply means of the paper supply means 200 includes two second paper supply rollers 226, 226 fixed to both sides of the delivery roller 212 loosely fitted to the first drive shaft 210, and a lower surface side of the rollers 226, 226. And a driven roller 240 pressed so as to be driven and rotatable.

The second paper feed rollers 226, 226
The feed roller 212 has a slightly larger diameter and can be driven independently of the feed roller 212. When the feed roller 212 rotates, the feed roller 212 rotates in the same direction so as not to hinder the feeding of the document D.

A document detection sensor 241 is provided near the press-contact position of the driven roller 240 in the conveyance path downstream of the nip position between the feed roller 212 and the double feed prevention roller 213 in the feeding path. The document detection sensor 241 detects that the leading edge of one document separated and transmitted at the nip position of the document bundle passes.
It is turned ON and turned OFF when the trailing edge of the document D passes.

When the document detection sensor 241 detects the leading edge of the document, the solenoid is turned on after a predetermined time from the generation of the detection signal.
As a result, each member of the link mechanism is operated, and the movable guide plate 105 is lowered.

At the same time, the main motor 215 shifts from the reverse rotation to the forward rotation. At this time, the gear 23 of the second drive shaft 211
0, idler gear 232, gear 22 with one-way clutch built-in
7 (the rotation is not transmitted to the gear 228 containing the one-way clutch), the first drive shaft 210 still continues to rotate in the same direction, and the second supply shaft fixed to the shaft 210. Paper roller 2
26 also rotates continuously in the same direction.

However, with the forward rotation of the main motor 215, the second drive shaft 211 also shifts from the reverse rotation to the forward rotation.
The one-way clutch 223 provided at the shaft end of the drive shaft 211 causes the gear 224 to rotate freely, and neither the gear 225 meshing with the gear 224 nor the delivery roller 212 integral with the gear 225 transmits rotation.

Here, when the leading end of the document D is pressed and held between the second paper feed roller 226 and the driven roller 240, the document wound tightly around the free-rotating feed roller 212 and the normally rotating second paper feed roller 226. D causes the delivery roller 212 to rotate in the paper feeding direction.

The double feed prevention roller 213 performs an operation of continuously rotating forward since the first drive shaft 210 keeps rotating forward to prevent double feed of the second and subsequent originals and return. The second paper feed roller 226 continues to rotate thereafter and continuously feeds the separated original D to the transport unit 300.

The transport unit 300 is for transporting the original D on the platen glass 11, and includes a white sheet member 304 and the original transport roller 30.
1,302,303 are provided as main components. Note that the transport unit 300 may be an endless transport belt. The white sheet member 304 is used to press the document D during exposure, and is made of a plastic material having high solid lubricity (in this embodiment, PET = polyethylene terephthalate), and covers the entire upper surface of the platen glass. The white sheet member
304 has an end on the paper feed unit 200 side connected to the torsion coil spring, and an end on the paper discharge unit side connected to the fixing unit 101a of the housing body 101. In addition, three through holes 304a are provided at appropriate places along the center line of the white sheet member 304, and the ends of the document conveying rollers 301, 302, and 303 project.

The document transport rollers 301, 302, and 303 are for transporting the document D on the platen glass 11, and rotate while pressing the document D through the through-hole 304a so that the document D can be transported by frictional force.
A total of three white sheet members 304 are provided corresponding to the respective through holes 304a on the back surface side. The surfaces of the rollers 301, 302, and 303 are covered with an elastic material having a large frictional force (for example, a sponge body made of rubber or plastic), and the ends thereof are in contact with the surface of the platen glass 11 through the through holes 304a. The original transport rollers 301, 302, and 303 can be rotated forward and backward so that the final position of the original D can be finely adjusted at the time of exposure.

The main motor 215 drives the paper feed unit 200 and the transport unit 300 at the same time. That is, the gear 216 that is integral with the main shaft of the main motor 215 is connected to the transport drive unit 310 via a gear train, and drives the drive shaft (station shaft) 311 to rotate. A gear 316 is fixed to one shaft end of the drive shaft 311, and a timing pulley 317 is fixed near the other shaft end. The gear 316 is
It meshes with the small diameter gear 320. The small diameter gear 320 is integral with the large diameter gear 321, and the gear 321 is connected to the main motor 215.
Gear 216 which is integral with the motor shaft.

Thus, the driving torque of the main motor 215 is
21, 320, 316 to rotate the drive shaft 311.

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

A first transport roller unit 330 is disposed on the upstream side of the drive transport unit 310 via a timing belt 322. A second transport roller unit 340 is disposed downstream of the feed via a timing belt 323, and a third transport roller unit 350 is disposed downstream of the feed via a timing belt 324.

A timing pulley 331 is fixed at the center of a rotating shaft 301a integral with the document conveying roller 301. Both shafts of the timing pulley 331 are rotatably supported by bearings. Both ends of the rotation shaft are spring-biased,
The outer peripheral surface of the document conveying roller 301 is pressed against the platen glass 11 surface.

The first transport roller unit 330 configured as described above is pressed by the platen glass 11, and the driving is transmitted by the timing belt 322 wound around the timing pulleys 317 and 331.

The document conveying roller 302 of the second conveying roller unit 340 is similarly biased by a spring, and the rotation of the timing belt 323 rotates the timing pulley 341 to transmit the rotation.

The document conveying roller 303 of the third conveying roller unit 350 receives the driving force of the timing pulley 341 and the timing belt 324 by the timing pulley 351 and is rotated integrally with the timing pulley 351. The spring biasing force also presses the transport roller 303 to press the platen glass 11 side in the same manner as described above.

Next, the structure and drive system of the paper discharge unit 400 will be described with reference to FIGS.

Reference numerals 401, 401 denote paper feed rollers, which are integrated with the rotating shaft 410. Pinch rollers 402, 402 at the lower side (near the introduction opening) and pinch rollers 403, 403 at the upper side (near the discharge opening) are respectively supported by the mounting plates 408, 409 and are pressed against the discharge rollers 401 by the springs. doing.

Near the two shaft ends of the rotating shaft 410, a paper discharge guide roller 4
11,411 are freely fitted and rotatable. Both ends of the rotating shaft 410 are rotatably supported by a mounting plate 413 having a bearing 412.

One-way clutch 414 is attached to one end of the rotating shaft 410.
Is mounted. The gear 415 is
The idler shaft 417 implanted in the adjusting plate 416 is engaged with a rotatable gear 418 to fit. A timing belt 420 is wound around a timing pulley 419 that is integral with the gear 418 and rotates. The other timing pulley 421 that meshes with the timing belt 420 and rotates is fitted into an idler shaft 423 implanted in the mounting plate 422 and is rotatably supported. The timing pulley 421 includes gears 320,
321 and the main motor via gear 216
It is driven and rotated by 215.

Next, the operation of the document feeder according to the present invention will be described with reference to FIGS. 4 (A) to 4 (F), an explanatory diagram of the document transfer process, and a time chart of FIG.

First, a document is placed with its recording surface facing upward on a paper feed tray composed of a fixed paper feed tray 103 and a movable paper feed tray 102, and the leading edge of the document is inserted into the feed section of the paper feed opening. I do.
For convenience of explanation, the operation of transporting the _two documents D ₁ and D ₂ will be described.

(A) First paper feed When the copy button is pressed in this state, the solenoid is energized by the paper feed start signal to lower the tip of the movable guide plate 105, and at the same time, the main motor 215 starts reverse rotation. The reverse rotation of the main motor 215 causes the stacked original D
₁ and D ₂ are sent out while being sandwiched between a sending-out roller (first sheet feeding roller) 212 and a sending-out lever 201.
12 and the upper document D ₂ at the nip position of the double feed prevention roller 213 is returned, only the lower layer of the document D ₁ is fed is separated.

(B) When the second paper feeding original D ₁ tip passes the document sensor 241, from the detection signal after 150 ms, with return the movable guide plate 105 upward and OFF the solenoid, positive the main motor 215 from the reverse Switch to inversion. With this, the feeding roller
212 becomes free rotation, by a driven roller 240 for pressing the driving rotation and to the second feed roller 226, the document D ₁ is slipped upper surface of the plate 12 butting, reached on the platen glass 11, a white sheet member The sheet slides while passing through a gap with the sheet member 304, and is pressed and conveyed by document conveying rollers 301, 302, and 303 driven and rotated through a through hole 304a of the sheet member 304, and advances.

Trailing edge of the document D ₁ and (C) a document abutting is, when passing through the document detecting sensor 241, after counting up the 45 pulses from the detection signal generation, the main motor 215 is switched from the normal rotation to reverse rotation. At the time of this switching start, but the trailing edge of the document D ₁ is the right than the stop surface of the plate 12 by the butting, by the reverse rotation of the main motor 215, the document conveying rollers 301, 302, 303 is rotated clockwise, the document D ₁ And the butting plate 21
Contact the stopper surface of 5. Further, after counting up the above-mentioned 45 pulses, after further counting 28 pulses, the white sheet member 304 is lowered by the swivel bag portion (see FIG. 2 (E)) driven by the main motor 215, and Because the gap between the plates 12 is closed, the original
D ₁ is never reverts back to the feeding portion 200 jump over the plate 12 butting. Furthermore, the document D ₁ is in close contact is pressed by the platen glass 11 by the white sheet member 304. Exposure is performed in the stop-contact state of the document D _1.

(D) Start of Discharge When the above exposure is completed, the main motor 215 is switched from reverse rotation to normal rotation again. This allows the transport roller 30
1,302,303 is rotated forward to feed the document D ₁ in the direction of the discharge portion 400. The leading end of the original D ₁ passes through the nip position of the pinch roller 402 in pressure contact therewith and discharge roller 401 rotates forward through the guide plate, the paper discharge sensor 404 provided further in the conveying path of the paper output unit 400 Pass the detection position of. The forward rotation of the main motor 215 is switched to the reverse rotation by the generation of the document leading edge detection signal.
Original D ₁ is advanced, passes through a nip position between the sheet discharging roller 401 and the pinch roller 403, and stops reaching the vicinity of the paper discharge opening.

(E) The transport rollers 301, 302, and 303 are temporarily stopped and the first paper feed roller 216 is rotated in reverse.
But it reversed, an attempt to retract the vicinity of the rear end of the document D ₁ to pressure clamping.

On the other hand, since the one-way clutch 414 is provided at the shaft end of the sheet discharge roller 401, the one-way clutch 414 is locked when the main motor 215 rotates in the reverse direction, and the rotation is stopped. By setting this time strengthening the pressing force to the discharge roller 401 of the pinch roller 402 and 403, near the tip of the document D ₁ is being held strongly by these rollers, after the document D ₁ by reverse rotation of the conveying roller 30,302,303 It overcomes the retraction force of the end, to hold the document D ₁ in the suspended state.

Also, when the main motor 215 rotates in the reverse direction,
0, the transport unit 300 becomes similar to the state as FIG. 4 (A), and feed roller 213 forward, is fed through the nip position between prevention roller 213 is next document D ₂ multifeed . That is, the second original D ₂ is fed into the first paper discharge process of the document D ₁ first
Start feeding paper.

(F) When the leading end of the sheet discharge resuming the second original D ₂ the second paper feed passes through the document detecting sensor 241, the main motor 215 is switched from the reverse rotation to forward rotation,
Figure 4 likewise the original D ₂ and (B) together is conveyed from the second feed position in the direction of the platen glass 11, the sheet discharge roller 40
1, and the discharge conveying the document D ₁ by normal rotation of conveying rollers 301, 302, 303, placed on the outside of the ejection tray 406 by releasing from the sheet discharge opening. Second document D ₂ of the rear product also conveyed discharging operation in the same manner are stacked on the sequential ejection tray 406 is repeated.

In the above embodiment, the original is reversely fed by the main motor reverse rotation in the process of FIG. 4 (C) and brought into contact with the abutting surface. However, the present invention is not limited to the above embodiment. The present invention can also be applied to a document feeder having a structure in which the leading end of a document abuts on the movable abutting plate on the downstream side of the transfer at one end of the platen glass while rotating forward.

〔The invention's effect〕

As described above, the document feeder of the present invention has a single drive source for the paper feed unit, the document feed unit, and the paper discharge unit, thereby realizing a thinner device, improved maintainability, improved reliability, and the like. Despite being an apparatus, it is possible to shorten the document conveyance interval by starting to feed the next document in the process of discharging the preceding document, thereby increasing the number of documents conveyed per unit time. Further, such an effect is obtained with minimum cost increase.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a document feeder according to the present invention, FIG. 2 is a drive system diagram of the entire document feeder, FIG. 3 is a plan view of a discharge roller and its drive system, and FIG. FIG. 5 is a time chart for explaining the operation process of the document feeder. 11 Platen glass (document table) 12 Abutment plate, 100 Document transfer device 101 Housing body 102 Movable paper tray 103 Fixed paper tray 105 Movable guide plate 200 … Paper feed unit 201… Feeding lever 212… Feeding roller 213… Double feed prevention roller 215… Main motor (drive source) 241… Original detection sensor 300… Transport unit 301, 302, 303… Original transport roller 304… … White sheet member 400… paper discharge section, 401… paper discharge rollers 402, 403… pinch roller 404… paper discharge sensor 406… paper discharge plate 414… one-way clutch 415… gears, D ₁ , D ₂ …… Manuscript

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-111852 (JP, A) JP-A-62-161644 (JP, A)

Claims (1)

(57) [Claims] A sheet feeding unit for feeding a document placed on a sheet feeding tray one by one toward a document table of a document exposing unit; and a sheet feeding unit disposed on the document table and fed from the sheet feeding unit. A document transport section for transporting a document to be fed, a paper discharge section for transporting the document after the exposure processing in cooperation with the document transport section and discharging the document onto a paper discharge tray by a paper discharge roller; And a drive source for driving the document transport unit and the paper discharge unit, the paper discharge roller of the paper discharge unit is provided with a one-way clutch for preventing reverse rotation, When the driving direction of the driving source is switched and the second document is fed by the paper feeding unit while the document is being discharged after the end of the exposure by the paper roller, the one-way clutch prevents the discharge roller from rotating in the reverse direction. A document feeder, comprising: