JP3215307B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for separating and feeding sheet information one by one from a sheet material on which image information of a document set on a document reading apparatus is stacked.

[0002] In the above, the sheet material is, for example, a copying machine
In office equipment such as printers, printing machines, facsimile machines, and other equipment using various sheet materials, transfer paper, photosensitive paper, thermal paper, electrostatic recording paper, printing paper,
Sheets (cut sheets) such as manuscripts, cards, and envelopes. The material is not limited to paper.

[0003]

2. Description of the Related Art Conventionally, the following control is performed when a document is copied in a copying machine using an electrophotographic apparatus, for example.

FIG. 1 shows a copy operation in a conventional copying machine.
The description will be made with reference to FIG.

When an operator sets a document on the reading unit and selects the copy button, the CPU on the DC controller board
The recording motor M1 is driven based on a signal from the CPU, and when a signal for feeding the recording paper is transmitted from the CPU to the recording unit after a predetermined time, the paper feeding clutches (CL1, CL4)
Is turned on, the paper feed roller 206 rotates, and the recording paper is conveyed from the sheet material feeding unit. Thereafter, the feed roller release solenoids (SL1 and SL2) are turned on, and the feed roller 206 is separated from the recording paper surface.

[0006] The fed recording paper is conveyed by transport rollers 207.
And only one sheet is fed to the conveyance path by the separation roller 208. A certain time after the feed clutches (CL1, CL4) are turned on, the longitudinal pass roller drive clutches (CL2, C4)
L3) is turned ON, and the recording paper is transported by the vertical path roller 209 arranged so that the minimum-size paper can be transported. A vertical path roller 209 is used as a conveying means of the next stage of the recording paper.
Is reached, the conveyance roller 207 and the separation roller 208
Since the paper feed clutches (CL1 and CL4) are ON, a driving force rotating in the same direction as the conveyance roller 207 is transmitted to the separation roller 208, and the sheet material other than the uppermost sheet material is conveyed by the conveyance roller 207. And the separation roller 208 are prevented from entering the nip.

The longitudinal pass roller driving clutch (CL2, CL
After a certain period of time after 3) is turned on, the pre-registration roller drive clutch (CL9) is turned on, and is fed to the registration roller 211 by the pre-registration roller 210 which has been rotated. Although not shown in the figure, a sensor is provided immediately before the pre-registration roller 210, and if the recording paper does not arrive after a predetermined time, it is determined that a jam has occurred. The paper feed clutches (CL1, CL4) are turned off a predetermined time after the recording paper reaches the pre-registration roller 210.

The recording paper conveyed to the registration roller 211 has the registration roller drive clutch (CL8) turned off.
Therefore, a loop is formed when the registration roller 211 is stopped, and the skew of the recording paper is corrected.
It is held by the registration roller 211.

The drive of the optical system motor is started by turning on / off the registration roller 211, the document is exposed by the document illumination lamp 212, and the reflected light is reflected by the mirror 21.
3 irradiates the CCD unit 214. CCD unit 21
4 based on the image information of the original read by
By controlling ON / OFF of the image, an image of a dot pattern is formed on the photosensitive drum 216. The electrostatic latent image formed on the photosensitive drum 216 is stored in the developing unit 2 of the recording unit.
At 17, a visible image is formed by the toner.

The registration rollers 211 are so positioned that the leading edge of the image formed on the photosensitive drum 216 and the leading edge of the recording paper coincide.
Is driven, and the photosensitive drum 216 is
The upper image is transferred to recording paper. Then, the image that is merely placed on the recording paper is conveyed to the fixing unit 220 by the conveyance unit 219 so as not to give a shock to the recording paper, and heat and pressure are applied by the fixing unit 220 to be a permanent image. The recording paper on which the image information has been copied is stacked from a paper discharge unit 221 to a paper discharge tray detachably mounted on the apparatus.

[0011]

In the prior art as described above, it is necessary to continuously supply electric power to the electromagnetic clutch used, which consumes a large amount of power and wears the retard roller for a long time during rotation. Poor durability, requiring a sensor etc. to detect the position of the seat to control the electromagnetic clutch, etc., complicates the configuration, and requires complicated control because the electromagnetic clutch must be controlled based on the sensor, etc. And so on.

An object of the present invention is to provide a sheet feeding apparatus and an image forming apparatus which can solve the above-mentioned problems and can prevent double feeding of sheets with a simple structure without requiring an electromagnetic clutch. Aim.

[0013]

According to a first aspect of the present invention, there is provided a vehicle having a
Pick-up roller for feeding the sheet
A feed roller for feeding the delivered sheet by click-up roller, and pressed against the feed roller, multifeed
A retard roller that rotates in the sheet return direction to separate the sheet to be separated, and a retard roller that is disposed downstream of the feed roller in the sheet feeding direction and that is separated and fed by the feed roller and the retard roller. a conveying roller for conveying the fed sheets, the sheet feeding apparatus having a driving means for applying a force to rotate the feed roller and said retard roller, said driving hands
The stage transmits a driving force from a motor to the feed roller and the
One-way clutch and multiple gears for retard roller
A first transmission path for transmission via the feed roller
From the transmission to the retard roller via a plurality of gears.
And a second transmission path that reaches the first transmission path.
More wherein the driving force from the motor to more transmitted Fi
And the retard roller separates the sheet and feeds the sheet in the direction of the transport roller .
That after interrupting the driving force, it is conveyed by the conveying rollers Shi
The feed roller rotates along with the feed roller , and
The rotation of the feed roller is rotated by the second transmission path.
Is used to separate sheets that are double fed by the retard roller
Sheet feeding characterized by being transmitted in the
In the feeder .

According to a second aspect, in the first aspect, the module
Intermediate gear and notch in the input gear to which the motor drive is input
The pickup roller is connected via a notch gear having
The input gear is connected to an intermediate gear and the one wake
The feed roller is connected via a latch, and the
To the feed roller via the intermediate gear and torque limiter.
The retard roller is connected .
A third aspect of the present invention is any one of the above aspects, wherein the one-way
The engagement of the rotatable operating arm with the clutch causes the
The transmission of the drive by the first transmission path is interrupted.
Sign.

[0015] The fourth invention according to the present application is the aforementioned invention.
Any of the sheet feeders and unloading from the sheet feeder
Forming means for forming an image on a conveyed and conveyed sheet
And the following.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

<Overall Structure> An overall configuration of a facsimile apparatus as one embodiment of the present invention will be schematically described with reference to FIGS.

4 to 6, reference numeral 1 denotes an apparatus main body;
Is a document table configured to be able to stack a plurality of documents D on the top cover of the apparatus main body 1, 3 is an image reading unit that reads image information of the document D, 4 is a recording unit including a laser beam printer, Reference numeral 5 denotes a document conveying unit, 6 denotes a document pressing unit, 7 denotes a contact image sensor, 8 denotes a document discharge tray,
Reference numeral 9 denotes a laser scanner, 10 denotes an image forming unit, 11 denotes a sheet stacking device sheet feeding unit, 12 denotes a recording sheet discharge tray, 1 denotes a sheet stacking unit {P (multi-recording sheet) sheet stacking device, 14 denotes a cartridge cover, Reference numeral 15 denotes an ADF (automatic document feeder) cover, 16 denotes an upper document guide, 17 denotes a weight shaft, 18 denotes a document holding plate, 19 denotes a lower document guide, 20 denotes a partition between an image reading unit and a recording unit, and 21 denotes a facsimile. Control unit of the apparatus, 22 is a handset, 2 is a transport guide, 2
4 is an operation unit, 25 is a display unit, 26 is a tally lamp indicating the operation state of the facsimile machine, 27 is a second-stage sheet stacking unit, 28 is a light cover as a cover member, 29 is an MP sheet stacking unit sensor, and $ 0. Is an MP separation unit.

The image reading section 給 feeds and separates the originals D stacked on the original placing table 2 one by one by a preliminary transport roller 5b pressed against the preliminary transport pressing piece 5a and a separation roller 5d pressed against the reverse rotation roller 5c. The paper is further conveyed to the contact type image sensor 7 by a paper feed roller 5f pressed against a paper feed roller 5e pressed by a pressing spring 5k, and the weight shaft 1
7. After reading the image information of the original D while pressing the original D against the contact type image sensor 7 by the original pressing plate 18 and reading the image information of the original D, the discharging of the original D is pressed against the discharging roller 5g pressed by the pressing spring 5k. The document is discharged to the document discharge tray 8 by a paper roller 5h. During this time, the document D is guided by the upper document guide 16 and the lower document guide 19.

A slider 2a slidable in a direction perpendicular to the direction in which the original D is transported (in the width direction of the original D) is placed on the original placing table 2.
Is provided so that both sides of the document D stacked on the document table 2 can be aligned by the slider 2a. When the document D is a long document, by opening the extension document tray 2b, the rear end of the document D can be prevented from protruding from the document table 2 and hanging down.

The recording section 4 emits a modulation signal from a laser beam oscillator 9a of the laser scanner 9 based on the image signal output from the control section 21, and outputs the modulation beam to the photosensitive member of the image forming section 10 by a polygon mirror 9b. The drum 10a is irradiated with scanning light to form image information on the surface of the photoreceptor drum 10a, and is fed from the sheet stacking device sheet feeding unit 11, the second stage sheet stacking unit 27, or the MP sheet stacking unit 1 # to the image forming unit 10. After the image information is transferred and fixed on the recording paper S fed to the recording paper S, the paper is discharged onto the recording paper loading tray 12.

The photosensitive drum 10a is integrally incorporated in a recording cartridge 10e together with a primary charger 10b, a developing roller 10c, and a cleaning roller 10d, and is configured to be detachable from the apparatus main body 1. The surface of the photoreceptor drum 10a is uniformly charged by the primary charger 10b, and when the scanning light is reflected from the polygon mirror 9b and reflected by the return mirror 9c to irradiate the surface, a latent image is formed. The image is visualized by the toner supplied from 10c.

A transfer charger 10f is arranged around the photosensitive drum 10a of the image forming section 10, and a heat fixing device 10f is provided on a recording paper transport path downstream of the photosensitive drum 10a.
g, and a paper discharge roller 10h.

After the toner image formed on the surface of the photosensitive drum 10a is transferred to the recording paper S by the transfer charger 10f, the recording paper S is conveyed along the conveyance guide 2 #, and the toner image is fixed by the heat fixing device 10g. The recording paper is discharged to a recording paper discharge tray 12 by a paper discharge roller 10h.

The MP sheet stacking unit 13 is provided at the bottom of the main unit 1. The recording paper S loaded on the MP sheet loading device 13a is pressed by the pressure contact member 1 # b into the MP middle plate 1
The MP separation base 3 is pressed against the MP separation roller # 0a by being rotated upward, and is separated one by one by the MP separation pad # 0b (friction piece separation system).
0c, and is further transported by a transport roller 28a and a cover-side U-turn guide 2 disposed on the light cover 28.
8b and the main body side U-turn guide 28c arranged on the apparatus main body 1 side. Further, the recording paper S being fed.
Is fed by the registration sensor 28d so that the leading end of the toner image formed on the photosensitive drum 10a coincides with the leading end of the recording paper S, and the image output timing is adjusted. Photoconductor drum 10a
Conveyed between. The image is MP sheet loading device 13a
Is recorded on the lower surface side of the recording paper S loaded on the recording paper S.

The recording paper S has its side and rear end surfaces regulated by an MP regulating plate 1 # d movably mounted in accordance with the recording paper size so that skewing and non-feeding do not occur. The size and presence or absence of the recording sheet S are detected by the MP sheet stacking device sensor 29. The number of sheets that can be loaded on the recording paper is 100, and is configured to be pulled out to the left side toward the apparatus main body 1 (side loading method). The recording paper sizes that can be stacked are A4, Letter, and Legal.
Зd is set to A4 size.

The sheet stacking device sheet feeding section 11 is provided with a device main body 1.
The top plate 11h of the sheet stacking device paper feed unit 11 is disposed so as to be in contact with the bottom bottom surface of the sheet stacking device, and the top surface of the top plate 11h is the bottom plate of the apparatus main body 1. The recording sheet S stacked on the sheet stacking apparatus 100 is urged upward by the middle plate spring 104 by the middle plate spring 104, and is separated one by one by the semicircular sheet feeding roller 11b and the separation claw member 106 (claw). Separation method), the separated recording paper S is conveyed by the conveying roller 50 of the sheet stacking device, passes between the MP separation base # 0c and the paper passing guide 28e, and is disposed on the conveying roller 28a and the light cover 28. Cover-side U-turn guide 28
b and the main body side U-turn guide 28c arranged on the apparatus main body 1 side. From here on, it is the same as the sheet feeding from the MP sheet stacking unit 13 described above. The paper paths join immediately before the transport roller 28a. The image is recorded on the lower surface side of the recording paper S loaded on the sheet feeding device 100.

Although the second-stage sheet stacking device sheet feeding section 27 is omitted in FIG. 6, the configuration is substantially the same as that of the illustrated sheet stacking device sheet feeding section 11, and the inside of the second-stage sheet stacking device 101 is The recording paper S is fed to the recording unit 4 through the side space 11g of the sheet stacking device paper feeding unit 11.

Each of the sheet stacking apparatuses 100 and 101 has a stackable number of recording sheets of 500, and is configured to be pulled out to the front of the apparatus main body 1 (front loading method). The stackable recording paper sizes are mainly two types, A4 and letter.

The sheet stacking device sheet feeding unit 11 and the second-stage sheet stacking device sheet feeding unit 27 can be separated and combined as an option, and the total number of recordable sheets that can be stacked is 100 (sheet stacking). It is possible to vary from 1100 sheets (when the sheet stacking device sheet feeding unit 11 is provided in two stages) to 1100 sheets (when the sheet feeding unit 11 is provided in two stages). A cartridge cover 14 is provided on the apparatus main body 1 so as to be openable and closable. When the cartridge cover 14 is opened, the recording cartridge 10 e can be pulled out of the apparatus main body 1 and replaced. The cartridge cover 14 is provided with an interlock mechanism.
If 0e is not set in the apparatus main body 1, the recording unit 4
Is not working. The drum exposure prevention shutter 10i provided in the recording cartridge 10e is adapted to be linked with the setting of the recording cartridge 10e in the apparatus main body 1, and the cartridge cover 14 is opened to set the recording cartridge 10e in the apparatus main body 1. The hour shutter 10i is opened, and the shutter 10i is closed when the recording cartridge 10e is taken out of the apparatus main body 1, thereby preventing unnecessary exposure of the photosensitive drum 10a.

If a jam occurs during recording, the cartridge cover 14, the light cover 28, the paper discharge cover 1
The recording paper S staying inside can be taken out by opening one of the jam release cover 11i and the jam release cover 11i.

Further, it is necessary to open the discharge cover 10j after removing the recording paper discharge tray 12.

The partitioning section 20 is a duct for separating the image reading section З from the recording section 4, and the image reading section 3 has an adverse effect due to heat generated from the recording section 4 by flowing air by a fan (not shown). This prevents water vapor evaporating from the recording paper S from condensing and dropping onto the recording paper S.

The contact-type image sensor 7 has an L
Light is emitted from the ED array to the image information surface of the document D, and reflected light reflected from the image information surface is focused on a sensor element by a selfoc lens to read image information.

Although the above is an example of a facsimile, it goes without saying that the present invention can be applied to other image forming apparatuses.

<Configuration of Paper Feeding Unit> Next, an embodiment of the paper feeding unit on the image forming apparatus side will be described with reference to FIG.
This will be described with reference to FIGS. In FIGS. 1 to 3, reference numeral 300 denotes a first gear which receives a driving force, that is, a rotational force from a motor (not shown) via an intermediate gear as appropriate and is fixed to the feed roller 50 as a driving gear of the sheet feeding unit. The feed roller shaft 302 is rotatably loosely fitted to the feed roller shaft 302. First gear 30
0 is transmitted to the second gear 304 and the second gear 3
The rotation of 04 is a one-way clutch 30 such as a spring clutch.
6 to the third gear 308 and the third gear 3
The rotation of 08 is transmitted to a fourth gear 310 as a feed roller gear fixed to the feed roller shaft 302. The rotation of the fourth gear 310 is transmitted to the fifth gear 312, the torque limiter 314, and the sixth gear 316, and the rotation of the gear 316 is transmitted to the transmission shaft 198 via the seventh gear 318. . Further, the rotation of the transmission shaft 198 causes the eighth gear 320 and the ninth gear 32 in the holder 196 to rotate.
2. The retard roller 192 via the tenth gear 324
Is transmitted to The ninth gear 322 is supported by a support shaft 326.
The retard roller 192 and the tenth gear 324 are connected to the support shaft 3.
28, each is rotatably supported by the holder 196, but the extension of the support shaft 326 is not shown in FIG. Thus, the retard roller 192 is rotated by the rotational force from the first gear 300. Here, the first to tenth
Gears 300, 304, 308, 310, 312, 31
6, 318, 320, 322, 324 and one wake
The first transmission path is constituted by the latch 306, and the fourth to tenth transmission paths are formed.
Gears 310, 312, 316, 318, 320, 32
2, 324 constitute a second transmission path.

Reference numeral 330 denotes a notch gear corresponding to the second gear 304 having the notch 332, and the gear 330 is partially cut away and has a semi-lunar shape or the like.
1b is fixed to the pickup roller shaft 334 .
A control ring 338 having a notch 336 at one end of the pickup roller shaft 334 is fixed to the pickup roller shaft 334.
A claw member 342 driven by a solenoid 340 can be engaged with the notch 336. As shown in FIG.
A cam ring 346 having a concave portion 344 is provided on the control ring 338, and a spring 34 is provided between the control ring 338 and the apparatus main body 1.
8 are installed. First working arm 350 engaging with cam ring 346 and protrusion 3 of one-way clutch 306
52 L-shaped actuating lever 356 having a second operating arm 354 which engages is pivotally supported on the apparatus main body 1 in by a spring 358 shown in FIG. 3 that is biased in a counterclockwise direction.

The operation of the paper feeding unit will be described. First, in the standby state shown in FIG. 2, when the solenoid 340 is energized, the claw member 342 is actuated by the operation of the solenoid 340.
Engagement with the notch 336 of the control ring 338 is released, the control ring 33 8 rotates clockwise by the force of the spring 348 (FIG. 2). Then the control ring 33 8 and the notch gears 33 coaxial
0 is engaged with the second gear 304 and rotated, and this rotation is
Is transmitted to the pickup roller 11b through the pick-up roller shaft 334, the pickup roller 11b is to feed the uppermost sheet stacked on the sheet stacking device to the feed rollers 50. Pickup roller 1
Immediately before the rotation of the cam ring 346 and the contact with the sheet, the cam ring 346 is rotated.
The first operating arm 350 is engaged with the concave portion 344 of the second arm 354, and the operating lever 356 rotates counterclockwise to rotate the second operating arm 354.
Engaging the projection 352 of the one-way clutch 306 is released, the one-way clutch 306 becomes the power transmitting state, the first gear 300 second gear 304, the one-way clutch 306, third gear 308, the fourth Power is transmitted via the gear 310 and the shaft 302, and the feed roller 50 is rotated. The fourth gear 3
From the tenth, the fifth to tenth gears 312, 316, 31
When the power is transmitted through 8, 320, 326, and 328, the retard roller 192 is also rotated. Therefore, the feed roller 50 and the retard roller 192
The sheets are separated one by one and sent to a downstream conveying roller unit (not shown).

[0038] When the trailing edge of the sheet passes between the feed roller 50 and the retard roller 192, the notch gear 330 comes to the position of FIG. 1 by one rotation, previous to the solenoid 34
By cutting off the current of 0, the claw member 342 returned by a spring (not shown) engages with the notch 336 of the control ring 338, the notch gear 330 is stopped, the pickup roller 11b and the feed roller 50 are also stopped. Is in a standby state for sheet feeding.

In the embodiment of the sheet feeding apparatus, the pickup roller 11b and the retard roller 192
The tenth gear, the one-way clutch 306 , the torque limiter 314, etc., rotate in conjunction with each other to separate the sheet and feed it to the subsequent transport roller to complete the sheet feeding operation. Further, an electromagnetic clutch or the like for individually controlling the retard roller is not required, and the configuration is simplified. Also, the feed roller 5
0 and the retard roller 192 are connected via the torque limiter 314, so that when the sheet is multi-fed while the sheet is being conveyed by a conveyance roller (not shown) at the subsequent stage, the feed roller 50 The surrounding rotation is transmitted to the retard roller, and the multi-fed sheet can be separated. The one-way clutch 306 for rotating the feed roller 50 when the sheet is being fed by the subsequent transport roller is performed by a spring clutch for causing the retard roller 192 to make one rotation, thereby reducing the number of parts. Therefore, the configuration can be simplified, and the manufacturing cost can be reduced. In addition, since the retard roller 192 does not rotate more than necessary, it is possible to use an inexpensive roller that does not easily wear.

<Structure of Sheet Loading Device> Next, an embodiment of the sheet loading device according to the present invention will be described with reference to FIGS. 100 in the figure indicates the sheet stacking apparatus, the side plates 108, 110 of the sheet stacking apparatus 100 includes a pair of inner plates 112 in the back side of the sheet stacking apparatus 100 extending between the side plates 108 and 110, the sheet stacking apparatus 100 A front plate 114 and a bottom plate 116 extend between the side plates 108 and 110 on the near side. The middle plate 102 urged by the spring 104 is pivotally supported by a back plate 112 and a front plate 114 by pins 118.

Reference numeral 120 denotes an abutment member provided on the back side of the sheet stacking device.
An upper wall portion 122 corresponding to the upper side and an upright wall portion 124 corresponding to a side portion of the back plate 112 are provided.
26, the vertical wall portion 124 has a protruding portion 128 for regulating one side of the sheet, that is, the left side (upper side in FIG. 7) with respect to the sheet feeding direction.
The protrusion 130 is engageable with an appropriate number of adjustment holes 132 formed in the bottom plate 116 of the sheet stacking device. The separation claw member 106 provided forward in the sheet feeding direction of the abutting member 120 has a plate-shaped main body portion 136 having a guide hole 134 formed therein and a separation claw portion 138. Supported.
Since the separation claw member 106 is provided only on one side, the manufacturing cost is reduced.

A biasing means 1 having a plate-like member 142 for pushing the other side of the sheet, a spring (not shown) for biasing the plate-like member, etc., on the front side of the sheet stacking device, ie, inside the front plate 114.
44 are provided. Further, a positioning means 146 having an appropriate shape such as a substantially L-shaped cross section is provided on the upper portion of the front plate 114,
The reference surface 148 of the positioning means positions the sheet stacking device with respect to the image forming apparatus main body.

In the above configuration, the abutting member 120
Fits the projection 130 at the lower end thereof into an appropriate adjustment hole 132 in the bottom plate of the sheet stacking device according to the paper size, and
It is fixed to the back plate 112 by the screw 152 through the “0”.
When a predetermined number of sheets are stored in the sheet stacking apparatus 100 in this way, the sheet is pressed against the abutting member 120, that is, the back side by the urging means 144, and one side of the sheet is regulated by the reference surface of the protrusion 128. Will be. When the sheet stacking apparatus is mounted on the apparatus main body and stopped in such a state, the position of the sheet is defined by the abutting member, so that the sheet is prevented from being displaced as in the conventional front side regulation, and the sheet is prevented from being shifted. Is maintained in a predetermined position,
Good sheet conveyance can be performed without separation from the separation claw.

Paper as a sheet expands and contracts under the influence of humidity, but generally tends to be humid at high temperatures, but in any case, the sheet expands as the humidity increases. Further, the sheet stacking device expands as the temperature rises, but the sheet stacking device is often formed by resin molding, and the expansion tendency is more remarkable. Assuming that the positioning of the sheet is on the back side as described above, when the temperature is high and humid, the other side of the sheet is extended toward the front plate 114, that is, the front side, and the image forming character reference (image forming such as printing is performed on the left side of the sheet Is performed). However, when the sheet stacking apparatus is mounted on the apparatus main body and the sheet stacking apparatus is positioned with respect to the apparatus main body by the positioning means 146 provided on the front plate, the sheet extends to the front plate side, that is, the front side in a high-temperature and high-humidity environment. However, the abutment member serving as a reference for one side of the sheet moves to the back side due to the expansion of the sheet stacking device, that is, the extension of the sheet and the expansion of the sheet stacking device cancel each other, and the other side of the sheet. , The shift of the transport reference is reduced, and the shift of the image is prevented.

In the above structure, the abutting means has been described as the abutting member. However, the abutting plate may be provided with a reference surface to serve as the abutting means.

Next, another embodiment of the sheet stacking apparatus according to the present invention will be described mainly with reference to FIGS.

In FIGS. 11 and 12, separation pressure adjusting means 1
The adjustment lever 172 of 70 is accommodated in a concave portion 174 formed in the side plate 110 of the sheet stacking device 120, and one end thereof is pivotally supported by the side plate 110 by a shaft 176. The center of the upper side of the lever 172 has a taper 17 at the front and rear.
A projection 182 having 8, 180 is formed. A tension spring 188 is provided between the locking pin 184 at one end of the lever 172 and the locking pin 186 in the concave portion 174 of the side plate 110, and the lever 172 is urged counterclockwise in the drawing. The tension as shown in the drawing Ribane 1
88 is made as long as possible to increase the spring constant and lever 1
While the lever 72 is rotating, a retard roller 192 to be described later is
A substantially constant pressing force is applied to the pressure. A rail 190 is provided above the sheet stacking device 120. In FIG. 11, reference numeral 172A denotes a guided projection provided on the lever 172, which is slidable on the inner surface of the overhang portion of the concave portion 174 of the sheet stacking device.
72 is prevented from coming out of the recess.

On the other hand, the feed roller 5
0 is provided for the retard roller 192,
The retard roller is rotatably supported by a retard holder 196 having a projection 194 at a lower portion. The retard holder 196 is swingably supported by a support shaft 198. The main body 1 has a rail 19 of the sheet stacking device.
A rail 200 corresponding to 0 is provided.

According to the above embodiment, the sheet stacking device 1
When the device 20 is mounted on the apparatus main body 1 while being guided by the rails 190 and 200, the rail 200 on the main body side is mounted during mounting.
Adjustment lever 17 which was progressing while being pushed down by
As shown in FIG. 12, the second protrusion 182 engages with a hole formed in the rail 200 on the main body side in a click operation at the final stage of the mounting operation. By this operation, the user can sense that the sheet stacking device is mounted on the apparatus main body, stop the pushing operation of the sheet stacking apparatus, and collide the sheet stacking apparatus with the apparatus main body as described above to convey the sheet. It is possible to prevent deviation from the standardization.

When the sheet stacking apparatus is mounted on the apparatus main body as described above, the protrusion 182 of the adjustment lever 172 is provided.
Engages with the projection 194 of the retard holder 196, pushes up the retard holder 196 according to the urging force of the spring 188, and presses the retard holder 196 against the feed roller 50 with a desired separation pressure (FIG. 8). Thus, the separation pressure adjusting means 1
Since 70 is provided on the sheet stacking device side, replacement and adjustment of the adjusting means can be performed in a state where the sheet stacking device is pulled out from the apparatus main body, and the work becomes easy. Also, since the friction separating means is provided on the main body side,
It is not contaminated by hand oil. Although the present embodiment has been described with respect to the example of the separation pressure of the retard roller by the adjusting means, it is needless to say that the present invention can be applied to other friction separating means such as a friction pad.

[0051]

As described above , according to the present invention ,
The sheet loaded by the pickup roller is
Feed roller and feed low by motor drive.
Separate and convey the sheet that is fed multiple times by the roller and retard roller
After the interruption of the first transmission path feeding the rollers, the second transmission
By the path, the sheet conveyed by the conveyance roller
Therefore, the feed roller is rotated and the feed roller is rotated.
Rolled rotation of the roller is fed to the retard roller
To rotate the sheet to be separated
This eliminates the need for a conventional electromagnetic clutch or the like for individually controlling the pickup roller and the retard roller, thereby simplifying the configuration. In addition, since the feed roller and the retard roller are connected via the intermediate gear and the torque limiter, when the sheet is multi-fed while the sheet is being conveyed by the subsequent conveyance roller, the feed roller rotates with the feed roller. The rotation is transmitted to the retard roller, and the double feed can be eliminated.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of a paper feeding unit.

FIG. 2 is an operation explanatory diagram showing a standby state of the sheet feeding unit shown in FIG. 1;

FIG. 3 is an operation explanatory diagram showing a paper feeding state of the paper feeding unit shown in FIG. 1;

FIG. 4 is an overall perspective view of the image forming apparatus according to the present invention.

FIG. 5 is a front view of the image forming apparatus.

FIG. 6 is a sectional view showing internal details of the image forming apparatus.

FIG. 7 is a plan view of a sheet stacking apparatus according to an embodiment of the present invention.

FIG. 8 is a sectional view taken along the line AA in FIG. 7;

FIG. 9 is a front view of the butting member of the sheet stacking device in FIG. 7;

FIG. 10 is a plan view of an abutting member of the sheet stacking device in FIG. 7;

FIG. 11 is a side view of a sheet stacking apparatus according to another embodiment of the present invention.

12 is an explanatory diagram of an operation state of the sheet stacking device shown in FIG.

FIG. 13 is a diagram illustrating a copy operation of a conventional image forming apparatus.

FIG. 14 is a diagram mainly showing a transport system for describing a copy operation of a conventional image forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Device main body 2 ... Document mounting table 3 ... Image reading part 8 ... Discharge tray 11, 27 ... Sheet stacking device paper feeding part 12 ... Sheet discharge tray 100, 101 ... Sheet stacking device 102 ... Middle plate 106 ... Separation claw Members 108, 110 ...
Side plate 112 ... Back plate 114 ... Front plate 116 ... Bottom plate 120 ... Abutment member 122 ... Top wall portion 124 ... Standing wall portion 170 ... Separation pressure adjusting means 172 ... Adjustment lever 174 ... Concave portion 182 ... Protrusion 188 ... Spring 190, 200 ...
Rail 192 Retard roller 196 Retard holder 306 One-way clutch 314 Torque limiter 340 Solenoid 338 Control ring 356 Operating lever

Claims (4)

(57) [Claims] (1)Pick that feeds loaded sheets
Sent by up roller and pickup roller
Was doneA feed roller for feeding a sheet;
Pressed against the drollerTo separate multi-fed sheets,
To return the sheetRotatehandRetard to separate sheets
A roller and a downstream of the feed roller in a sheet feeding direction.
The feed roller and the retard draw
Conveyor that conveys the sheets separated and fed by theroller
Rotate the feed roller and the retard roller
Driving means for applying a power to cause the sheet to be fed.
In the device,The driving means transmits a driving force from a motor to the feed rod.
Roller and the retard roller with a one-way clutch and
A first transmission path for transmission via a number of gears;
From the feed roller to the retard roller via a plurality of gears.
And a second transmission path for transmitting rotation. From the motor transmitted by the first transmission path
 For driving forceThe feed roller and the retard draw
LaSeparate the sheet and transport itrollerFeed in the directionPrevious
By the first transmission routeAfter shutting off the driving force,Low
Sheet conveyed byBy the feed law
LaRotate with the feed roller
The second transmission path is double-fed to the retard roller.
To rotate the sheet to be separatedThis
And a sheet feeding device. Wherein said pick-up roller through the notch gear with an intermediate gear and the notch portion is connected to the input gear driving of the motor is inputted via said intermediate gear and said one-way clutch to the input gear Feed The sheet feeding device according to claim 1, wherein a roller is connected, and the retard roller is connected to the feed roller via an intermediate gear and a torque limiter. 3. A rotatable mechanism for the one-way clutch.
When the moving arm is engaged, the drive by the first transmission path is performed.
3. The transmission of motion is interrupted.
3. The sheet feeding device according to 1. 4. A sheet feeding device according to claim 1, further comprising: an image forming unit configured to form an image on a sheet fed and conveyed from the sheet feeding device. Image forming apparatus.