JPH0986683A - Sheet feeder and image forming device provided with the sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive sheet feeder without using an expensive clutch means of solenoid, electromagnetic clutch, etc. SOLUTION: When a sheet is fed, an arm 6 is turned in a direction Q with a separating roller shaft 10, an engaging condition of the second gear 4 and a lifter gear 2c is completely released. Accordingly, the lifter 2 is pressed by a lifter spring 3 to be turned, and the sheet is pressed to the separating roller shaft 10. On the other hand, when the separating roller shaft 10 is turned in a direction P at sheet feed standby time, the arm 6 is also turned with the separating roller shaft 10, the second gear 4 turnably supported on the arm 6 is meshed with the lifter gear 2c, and it is connected to the first gear 7 fixed to the separating roller shaft 10. Here, resistance in the direction impeding a turn acts in the arm 6 from a side of the lifter 2, so as to operate a torque limiter interposed between the arm 6 and the separating roller shaft 10, turning of the arm 6 is stopped. As a result, the lifter 2 is pressed down against the lifter spring 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an image forming apparatus such as a facsimile machine, a printer, a copying machine, and the like, and a sheet feeding apparatus for feeding a sheet to an image reading section of the image forming apparatus and the sheet feeding apparatus. The present invention relates to an image forming apparatus including a device.

[0002]

2. Description of the Related Art As a conventional sheet feeding apparatus, as shown in FIG. 8, a combination of a separation roller 201 and a separation pad 202 is widely known. This conventional example
The set sheet is pressed against the separation roller 201 by the middle plate 203. In the standby state for sheet feeding, the middle plate 203 is pushed down by a cam (not shown) so that the sheet is not pressed against the separation roller 201.

When a sheet is set on the intermediate plate 203 and paper feeding is started, a cam which pushes down the intermediate plate 203 is rotated by a clutch means (not shown) such as a solenoid so that the intermediate plate 203 is free. become. The intermediate plate 203 in the free state is raised (biased) by the force of a spring (not shown), and presses the sheet against the separation roller 201. Then, the sheet pressed by the intermediate plate 203 against the separation roller 201 is sent out by the separation roller 201 in the sheet feeding direction (for example, the image forming unit side).

[0004]

However, in the above-mentioned conventional example, expensive clutch means such as a solenoid or an electromagnetic clutch is used to control the rotation of the cam, and the product price of the sheet feeding apparatus is reduced. There has been a problem in that the price of the image forming apparatus using the sheet feeding apparatus rises, which in turn causes a sharp rise in the product price.

Therefore, an object of the present invention is to provide an inexpensive sheet feeding apparatus which does not use expensive clutch means such as a solenoid or an electromagnetic clutch, and an image forming apparatus equipped with the sheet feeding apparatus.

[0006]

A sheet feeding apparatus according to the present invention includes a sheet stacking unit for stacking sheets, a feeding unit for sending out the sheets on the sheet stacking unit, and a sheet for stacking the sheets on the sheet stacking unit. A sheet feeding device, comprising: a sheet pressing unit that presses a sheet feeding unit; the sheet feeding device is connected to an input member to which the sheet pressing unit is attached; and a drive shaft of the sheet feeding unit. And a gear device that engages with the input member and releases the sheet pressing state of the sheet pressing unit when rotated in the direction opposite to the feeding direction.

Further, in the sheet feeding apparatus of the present invention, the gear unit includes a first gear attached to the drive shaft, a second gear that revolves when meshed with the first gear, and the drive unit. An arm that is rotatably attached to the shaft and connects the first gear and the second gear, and integrally rotates the arm and the drive shaft when the load acting on the arm is less than a predetermined value. On the other hand, a torque limiter that allows relative rotation between the arm and the drive shaft when the load acting on the arm is equal to or greater than a predetermined value is provided.

Further, in the sheet feeding device of the present invention, the gear device is arranged in parallel with the drive shaft, and the support shaft rotates in the same direction as the drive shaft, and the first support device is attached to the support shaft. Gear, a second gear revolving by meshing with the first gear, an arm rotatably attached to the support shaft and connecting the first gear and the second gear, and the arm. When the load acting on the arm is less than a predetermined value, the arm and the support shaft are integrally rotated, while when the load acting on the arm is a predetermined value or more, the arm is relatively rotated with respect to the support shaft. And a torque limiter that allows the torque limiter.

Further, in the sheet feeding device of the present invention, when the input member is attached to the sheet pressing means and the drive shaft rotates in a direction opposite to the sheet feeding direction, the second member is provided.
2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a gear that meshes with the gear of FIG.

Further, the sheet feeding apparatus of the present invention comprises a separating means which cooperates with the feeding means to separate the sheets on the sheet stacking means one by one when the sheet is fed by the feeding means. It is characterized in that the separating means is provided with a stopper portion that regulates the leading end position of the sheets on the sheet stacking means.

Further, the sheet feeding apparatus of the present invention is arranged at a one-way clutch for integrally rotating the feeding means and the drive shaft at the time of feeding a sheet, and a downstream side of the feeding means in the sheet conveying direction. And a conveying unit that conveys the sheet at a higher speed than the feeding unit.

Further, the image forming apparatus of the present invention comprises the sheet feeding device described in any one of the above, and an image reading means for reading the image information of the sheet fed by the sheet feeding device. It is characterized by that.

Furthermore, the image forming apparatus of the present invention comprises the sheet feeding device described in any one of the above, and an image forming means for forming an image on the sheet fed by the sheet feeding device. It is characterized by that.

According to the structure of the present invention, when the drive shaft is rotated in the sheet feeding direction, the feeding means feeds the sheets one by one on the sheet stacking means urged by the sheet pressing means. To do. On the other hand, when the drive shaft rotates in the direction opposite to the sheet feeding direction, the gear device engages with the input member of the sheet pressing means to release the sheet pressing state of the sheet pressing means. No sheets on the means are fed.

Further, according to the structure of the present invention, when the drive shaft and the first gear rotate in the sheet feeding direction during sheet feeding, the arm works together with the drive shaft and the first gear due to the action of the torque limiter. Rotate. At that time, the second gear is
It revolves around the gears while rotating on its axis. As a result, the engagement between the input member on the sheet pressing means side and the second gear is completely released, and the sheet pressing means presses the sheet toward the feeding means side. Therefore, the feeding unit feeds the sheets on the sheet stacking unit one by one. On the other hand, when the drive shaft and the first gear rotate in the opposite direction to that during the sheet feeding during the sheet feeding standby, the arm rotates together with the driving shaft and the first gear due to the action of the torque limiter. When the second gear is engaged with the input member on the side of the sheet pressing means and the arm receives resistance from the side of the sheet pressing means that is greater than a predetermined value in the direction of preventing the rotation, the arm rotates due to the action of the torque limiter. To stop.
As a result, the second gear drives the input member, and the sheet pressing state of the sheet pressing means is released. Therefore, it is possible to stack or take out the sheets on the sheet stacking unit.

Further, according to the present invention, when the sheet is conveyed by the sheet conveying means, the one-way clutch allows the relative rotation between the feeding means and the drive shaft, and the feeding means operates according to the movement of the sheet.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. <First Embodiment> FIG. 1 shows a first embodiment of the present invention.
It will be described with reference to FIG. Among these, FIG. 1 is a perspective view of a main part of the sheet feeding device K showing the present embodiment. FIG. 2 is a main part perspective view showing an operating state of the sheet feeding device K. FIG. 3 is a plan view of a main part of the sheet feeding device K. FIG. 4 is a side sectional view of the sheet feeding device K. FIG. 5 is a time chart diagram showing an operating state of the sheet feeding apparatus K. FIG. 6 is a side sectional side view of a facsimile machine using the sheet feeding device K. Figure 7
FIG. 4 is a perspective view of a facsimile machine using the sheet feeding device K.

(Structure of Sheet Feeding Device) First, in FIG. 1 and FIG. 2, a lifter (sheet pressing means) 2 is rotated by a predetermined angle on a document table 1 as a sheet stacking means for stacking sheets. It is installed. This lifter 2
Is engaged with the concave portion 1a of the document table 1, and its shaft portion 2
Fan-shaped lifter gear at the tip of ₁ (gear as input member)
2c is fixed, the shaft portion 2 ₁ of the tip portion 2a,
2b is rotatably supported by a bearing (not shown) on the apparatus body side (see FIG. 3). The tongue-shaped sheet pressing portion 2e of the lifter 2 is constantly pressed upward in the drawing by the spring 3.

The separating roller 12 as a feeding means for feeding the sheets stacked on the original table 1 and the lifter 2 is
It is engaged with the separation roller shaft (driving shaft) 10 via a spring clutch (one-way clutch) 13. When the separation roller shaft 10 rotates in the Q direction, the spring clutch 13
When a load is applied to the separation roller 12 in the direction opposite to the Q direction (P direction), the separation roller shaft 10 and the separation roller 12 function to rotate integrally. On the other hand, the spring clutch 13
When the separation roller shaft 10 rotates in the P direction, when a load in the direction opposite to the P direction (Q direction) acts on the separation roller,
The separating roller shaft 10 and the separating roller 12 function to rotate relative to each other. Further, when the separation roller 12 rotates faster than the separation roller shaft 10 when the separation roller shaft 10 rotates in the Q direction, the spring clutch 13 causes the separation roller shaft 10 to rotate.
And the separating roller 12 rotate relative to each other.

The separating roller shaft 10 has its end portion rotatably engaged with a bearing of the apparatus main body (not shown).
A transmission core 11 engaging with the spring clutch 13 is fixed to a portion of the separation roller shaft 10 facing the spring clutch 13. The transmission core 11 also constitutes a part of the separation roller shaft 10. ing. A first gear 7, which is connected to a motor 30 as a drive source via the separation roller shaft 10, is fixed to a portion of the separation roller shaft 10 facing the lifter gear 2c. An arm 6 is attached to the separation roller shaft 10 so as to be located on the left side of the first gear 7 in the figure.

The arm 6 rotates integrally with the separation roller shaft 10 by frictional resistance received from a slotted washer as a torque limiter interposed between the first gear 7 and a disc spring (not shown). Although it moves, when a rotation resistance larger than the frictional resistance is received, slipping occurs (relative rotation) with respect to the separation roller shaft 10. At the end of this arm 6,
A second gear 4 meshing with the first gear 7 is rotatably supported via a support shaft 5. Then, the second gear 4 rotates around the separation roller shaft 10 together with the arm 6 to engage / disengage with the lifter gear 2c, and the motor 30
The rotation power of the above is transmitted to and cut off from the lifter gear 4. As shown in FIG. 2, the arm 6 comes into contact with a stopper 8 extending from the apparatus main body side (not shown) to regulate the amount of rotation thereof. A gear unit is constituted by the first gear 7, the arm 6, the second gear 4 and the torque limiter.

Next, in addition to FIGS. 1 and 2, FIGS.
The configuration of the sheet feeding apparatus according to the present embodiment will be described with reference to FIG.

[0023] The separation roller 12 and the cooperation with the separation pad holder 15 for separating the sheets one by one with the non-illustrated platen through legs 15 ₁ of the shaft 15a extending from the end thereof, the 15b It is rotatably attached to the first bearing portion.
The separation pad holder 15 has a separation pad (separation means) 14 at a portion of the base portion 15d facing the separation roller 12.
And is always biased toward the separation roller 12 by the spring 16. The side surface 15c of the base portion of the separation pad holder 15 is provided with the original table 1 and the lifter 2.
When a sheet is stacked on the sheet, it functions as a stopper portion that regulates the leading end position of the sheet. As a result, the posture of the seat is adjusted, and more accurate and reliable seat feeding is possible. Further, the alignment of the sheets on the document table 1 is improved,
It becomes easy to set the sheet on the document table 1.

As shown in FIG. 4, the sheet S sent out from the original table 1 by the separating roller 12 is the conveying roller 1
7 and a conveying roller 18 that follows the conveying roller 17 conveys the sheet along the U-turn path 19, and a sheet feeding roller 20 and a sheet feeding roller 21 that follows the sheet feeding roller 20 cause a contact sensor (image reading means) 22 It is transported to a predetermined position. The transport roller 17 and the transport roller 1
The numeral 8 constitutes a conveying means, and conveys the sheet at a speed higher than that of the separating roller 12. Therefore, the separating roller 12 is rotated (overrunning) by the sheet conveyed by the conveying roller 17 and the conveying roller 18, the conveying speed of the sheet is not affected by the speed of the separating roller 12, and the sheet is conveyed. The transport speed is stable. Then, after the image information of the sheet is read by the contact sensor 22, the discharge roller 23 and the discharge roller 23
The sheet is discharged onto the sheet discharge tray 25 by the sheet discharge roller 24 that follows. A sensor DS26 for detecting the presence or absence of a sheet is arranged in front of the nip portion between the separation roller 12 and the separation pad 14 (on the right side in FIG. 4). A sensor DES that detects the leading edge and the trailing edge of the sheet is arranged in front of the contact sensor 22 (on the left side in FIG. 4).

(Operation of Sheet Feeding Device) Next, the basic operation of the sheet feeding device according to the present embodiment will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a standby state for waiting for a document in the sheet feeding apparatus. At the stage before the figure, the separation roller gear 7 and the separation roller shaft 10 are sufficiently rotated in the direction of arrow P, the second gear 4 is rotated in the direction of P ′, and the lifter gear 2c is pushed down, so that the lifter 2 moves. It stands by at the lower position (position shown in FIG. 1) against the pressing force of the spring 3. In this state, one or a plurality of originals are set so that their leading ends abut against the base side surface (stopper portion for controlling the leading end position of the originals) 15c of the separation pad holder 15, and then a reading start button (not shown) of the apparatus is set. Press
The separation roller gear 7 and the separation roller shaft 10 rotate in the direction of arrow Q by a drive source (not shown).

Then, the arm 6 rotates along with the separation roller gear 7 and rotates clockwise in FIG. 1, so that the second gear 4 separates from the lifter gear 2c. In response to this, the lifter 2 is biased by the spring 16 and rises, and presses the sheet (original) against the separation roller 12 as shown in FIG. The arm 6 is stopped at a predetermined rotation position by a stopper 8 so as not to rotate too much.

On the other hand, when the separation roller shaft 10 rotates in the Q direction, the separation spring clutch 13 transmits the rotational force of the motor 30 from the transmission core 11 which is fixed to the separation roller shaft 10 and rotates to the body of the separation roller 12. Then, the separation roller 12 is rotated in the direction of arrow Q. The sheets S are separated one by one from the uppermost one by the cooperation of the separation roller 12 and the separation pad 14 and sent out, and further conveyed along the U turn path 19 by the conveyance roller 17 and the conveyance roller 18, and the image is obtained. It is conveyed to the contact sensor 22 as a reading unit (see FIG. 4). 4 is a cross-sectional view of the sheet feeding device in which the lifter 2 is raised and the sheet is pressed against the separation roller 12.

After the work of reading the image information of the sheet by the contact sensor 22 is completed, the sheet is discharged onto the sheet discharge tray 2.
When discharged to 5, the motor 30 as a drive source is reversely rotated by the CPU 31 as a control unit, and the separation roller gear 7 and the separation roller shaft 10 rotate in the direction of arrow P. Then, the arm 6 rotates together with the separation roller gear 7, and when the lifter gear 2c and the second gear 4 mesh with each other, a load acts on the arm 6 and the rotation of the arm 6 stops.
The rotational force of the motor 30 is transmitted from the second gear 4 to the lifter gear 2c side. As a result, the lifter gear 2c rotates in the direction opposite to the P'direction (clockwise direction in FIG. 1), and as shown in FIG. 1, the lifter 2 resists the pressing force of the spring 3 and moves to the lower position (FIG. 1). (The bottom position shown in) is pushed down. At this time, the separation roller 12 is in contact with the separation pad 14 and receives frictional resistance from the separation pad 14 so as to prevent the rotation, and the action of the spring clutch 13 causes the separation roller 12 to move with the separation roller shaft 10. Since the relative rotation is permitted, the rotation is stopped. Therefore, the sheet on the document table 1 is not turned up by the separation roller 12.

Since the lifter gear 2c is formed in a fan shape, the meshing with the second gear 4 is released when it is rotated by a predetermined amount. As a result, the transmission of the turning force from the motor 30 to the lifter 2 side is cut off. The motor 30 rotates by a predetermined amount even after the meshing state of the second gear 4 and the lifter gear 2c is released, and then stops by the control signal from the CPU 31. Then, the sheet feeding apparatus is in a standby state waiting for a document.

Here, the lifter gear 2c is the lifter 2c.
Since the fan-shaped shape is set so that the gear end portion appears in a state in which the lifter gear 2c is in the right position, the lifter gear 2c will not rotate too much. That is, the lifter 2 is not damaged by being pressed by the document table 1. Further, the lifter gear 2c is prevented from rotating clockwise in FIG. 1 by contacting the second gear 4. Therefore, the position of the lifter 2 is held.

As described above, according to the present embodiment, the lifter 2 can be operated by a simple mechanical mechanism without using expensive electric parts such as a solenoid and an electromagnetic clutch, and the seat can be operated. It is possible to reduce the size and cost of the feeding device.

(Control State of Sheet Feeding Device) Next, the control state of the sheet feeding device will be described with reference to the timing chart of FIG.

FIG. 5 is a timing chart of forward / reverse rotation of the motor (driving source) 30, start button, on / off of the sensor, and the like. In the figure, motor
Is the motor 30 of FIG. 1, and cw is the motor 30.
Represents the forward rotation (direction of arrow Q in FIG. 1) of cc
w represents the reverse rotation of the motor 30 (direction of arrow P in FIG. 1).

As shown in FIG. 5, when the rear end of the sheet passes the sensor DS26 and a predetermined time or more elapses,
The rear edge of the sheet passes the sensor DES27 (sensor DE
S27 shifts from the on state to the off state). After that, the sheet is completely discharged to the discharge tray 25 while the motor 30 rotates forward for a predetermined time. After that, the motor 30 is stopped for about 0.5 seconds and then is connected to the lifter gear 2c via the first gear 7 and the second gear 4 while rotating in the reverse direction for a predetermined time, and rotates the lifter gear 2c to lift the lifter gear 2c. 2 is lowered to shift to the standby state for waiting the document (the state shown in FIG. 1).

In the present embodiment, even when the sheet feeding apparatus is initialized, such as when the sheet feeding apparatus is activated, the motor 30 is reversely rotated for a predetermined time to shift to the standby state.
The PU 31 controls the motor 30 and the like.

(Facsimile Device Equipped with Sheet Feeding Device) Next, a facsimile device using the sheet feeding device will be described in detail with reference to FIGS. 6 and 7.

FIG. 6 is a sectional view of the entire facsimile apparatus according to this embodiment. FIG. 7 is a perspective view showing the appearance of the facsimile machine.

The image reading section 103 for reading the image information of the sheet (original) presses the sheets stacked on the original table 102 (original table 1 in FIG. 1) to the separation pad 106a (separation pad 14 in FIG. 1) and pressure. Separation roller 106b (see FIG.
And the separating roller 12) for separating and sending out one by one.
Then, the delivered sheet is conveyed by the conveyance roller 106d.
A U-turn path (FIG. 4) formed by a part of the outer sheet guide 116 and the inner sheet guide 118 by the (conveying roller 17 of FIG. 1) and the conveying roller 106c (conveying roller 18 of FIG. 1).
It is transported in the U-turn path 19). In addition, transport roller 1
06c is pressed against the conveying roller 106d by a pressing spring (not shown). Further, in FIG. 6, 105 is a display unit
An operation unit including input keys and the like, and 106 is a sheet conveying unit.

Then, the sheet is further fed by the paper feed roller 106.
e (paper feed roller 21 of FIG. 4) and paper feed roller 106f (FIG. 4)
Of the contact type image sensor 108
(Contact sensor 22 in FIG. 4) and is pressed by the contact image sensor 108 by the elastic force of the sheet pressing plate 117 deformed by the sheet pressing portion 107, and image information is read by the contact image sensor 108. To be After that, the sheet is discharged onto the discharge tray 109 by the discharge roller 106h (the discharge roller 23 in FIG. 4) and the discharge roller 106g (the discharge roller 24 in FIG. 4). During this time, the sheet is guided by the outer sheet guide 116 and the inner sheet guide 118.

On the original table 102, a slider 1 is slidable in a direction perpendicular to the sheet conveying direction (sheet width direction).
02a is provided, and both sides of the sheet on the document table 102 can be aligned by the slider 102a. When the sheet is a long sheet, by opening the extension sheet tray 102b, it is possible to prevent the trailing end of the sheet from protruding from the document table 102 and hanging down.

The recording apparatus main body 104, which is a laser beam printer or the like, has a laser scanner 110 based on an image signal output from the control unit 120 (CPU 31 in FIG. 1).
Emitting a modulation signal from a laser beam oscillator (not shown)
The modulated beam is applied to the photosensitive drum 111a of the image forming section 111 as scanning light by the polygon mirror 110b to form image information on the surface of the photosensitive drum 111a, and the recording sheet fed from the cassette sheet feeding section 112 to the image forming section 111 is recorded. After the image information is transferred and fixed on the sheet for use, the recorded sheet is ejected to the sheet ejection unit 113.

The photosensitive drum 111a is a primary charger 111.
b, developing roller 111c and cleaning blade 11
It is integrally incorporated in the recording cartridge 111e together with 1d and is configured to be detachable from the apparatus main body 101. The surface of the photosensitive drum 111a is uniformly charged by the primary charger 111b, and when the scanning light from the polygon mirror 110b is reflected by the folding mirror 110c and irradiated, a latent image is formed on the surface of the photosensitive drum 111a. The image is made visible by the toner supplied from the developing roller 111c.

A transfer charger 111f is arranged around the photosensitive drum 111a of the image forming section (image forming means) 111. Further, a thermal fixing device 111g and a paper discharge roller 111h are arranged in the sheet conveyance path downstream of the photosensitive drum 111a in the sheet conveyance direction.

After the toner image formed on the surface of the photosensitive drum 111a is transferred by the transfer charger 111f to the sheet,
The thermal fixing device 1 is conveyed along the recording sheet conveying portion 121.
The toner image is fixed at 11 g and is discharged to the sheet discharge unit 113 by the discharge roller 111 h.

The sheet conveying guide 121a has conveying belts 121b and 121c in a V shape at the center thereof, assists in the sheet conveying from the downstream of the photosensitive drum 111a to the heat fixing device 111g, and also the photosensitive drum 111a. A sheet shorter than the conveyance path length of the heat fixing device 111g can be conveyed without disturbing the toner image.

The cassette paper feed unit 112 is the main body 101 of the apparatus.
It is arranged at the bottom of the. For the sheets stacked in the paper feed cassette 112a, the middle plate 112e is urged upward in FIG.
b and a pair of separation claws (not shown) separate them one by one (claw separation method), and the paper is fed from the paper feed cassette 112a. Thereafter, the sheet is transferred to the cassette conveying roller pair 112.
The sheet conveyance inner guide 121 ₁ which is conveyed by c and is constituted by a part of the main body frame forming the skeleton of the apparatus main body 101
When a cover side U-turn guide 121 ₂ disposed on the front cover 122, main body side U disposed in the apparatus main body 1
It is reversed by the turn guide 121 ₃ . Further, the leading edge position of the sheet being fed is detected by the registration sensor 121f, and the feeding timing and the image output timing are adjusted so that the leading edge coincides with the leading edge of the toner image formed on the photosensitive drum 101a. After that, transfer charger 1
It is conveyed between 11f and the photosensitive drum 111a.

This recording sheet is a sheet regulating plate 112 mounted so as to be movable according to the sheet size.
By d, the side end surface and the rear end surface of the sheet are regulated, and skew feeding and feeding failure do not occur. The image is the paper feed cassette 112a
The recording is performed on the lower surface side of the recording sheets stacked on. The presence or absence of the recording sheet and its size are detected by a cassette sensor (not shown).

As an example of the cassette 112a which has been put into practical use, about 250 sheets can be stacked, and it faces the apparatus main body 101 in the front direction (left direction in FIG. 6).
Some are configured to be pulled out to (front loading method). Also, the cassette 112a
Can stack sheets of seven sizes, A3, A4, A5, B4, B5, Letter, and Legal.

Also, by removing the front cover and setting the MP (multi-paper) tray 125, it becomes possible to feed postcards and business cards. For example,
The MP tray 125 has about 100 sheets (postcards, etc.)
Can be loaded.

Further, a cassette sheet feeding unit 1 (not shown)
The second-stage cassette paper feeding unit having the same configuration as that of 12 can be optionally separated and combined with the cassette paper feeding unit 112, so that the entire facsimile machine has about 100 to about 600 sheets. It is possible to stack up to one sheet.

The apparatus main body 101 is provided with a cartridge cover 114 which can be opened and closed. By opening the cartridge cover 114, the recording cartridge 11
1e can be pulled out of the apparatus main body 101 to be replaced. Further, since the cartridge cover 114 is provided with the interlock mechanism, the recording apparatus main body 104 is prevented from operating when the cartridge cover 114 is opened or the recording cartridge 111e is not set in the apparatus main body 101. Has become.

Further, the drum photosensitive prevention shutter 111i provided in the recording cartridge 111e is designed to interlock with the setting of the recording cartridge 111e to the apparatus main body 101. That is, the shutter 111i is opened when the cartridge cover 114 is opened and the recording cartridge 111e is set in the apparatus main body 101. On the other hand, the recording cartridge 111e is attached to the apparatus main body 101.
The shutter 111i is closed when it is taken out from, so that unnecessary exposure of the photosensitive drum 111a is prevented.

When a jam occurs during recording, any one of the cartridge cover 114, the front cover 122 and the paper discharge cover 123 can be opened to take out the sheet staying inside. There is.

The partition section 119 is a duct for separating the image reading section 103 and the recording apparatus main body 104. The partition portion 119 that functions as this duct radiates the heat generated from the recording apparatus main body 104 when air is blown by a fan (not shown), and prevents the image reading portion 103 from being adversely affected by the heat. It prevents the vaporized water vapor from dripping on the sheet due to dew condensation.

The contact-type image sensor 108 irradiates the image information surface of the sheet (original) with light from the LED array as the light source, and the reflected light reflected from the image information surface is coupled to the sensor element by the lens, and the sheet sensor The image information is read.

In FIG. 7, a regulation plate 102a for regulating the widthwise end position of the sheet (original) on the document supporting surface 102b is attached to the document table 102 so as to be slidable in the width direction.

As described above, the facsimile apparatus according to the present embodiment is provided with the above-described downsized and inexpensive sheet feeding apparatus, and as a result, the facsimile apparatus can be downsized and reduced in cost. it can. <Second Embodiment> In the first embodiment, the separation roller gear 7 and the arm 6 are arranged coaxially with the separation roller shaft 10, but the first gear 7 and the arm 6 are attached. A support shaft for this may be provided separately from the separation roller shaft 10. In this case, the degree of freedom in arranging the lifter gear 2c and the arm 6 is increased, and various variations in the device configuration can be provided. <Third Embodiment> In the first embodiment, the spring clutch 13 is used as the mechanical one-way clutch of the separation roller 12, but a needle clutch or the like may be used instead of the spring clutch 13. In the case of this embodiment, as compared with the case of the first embodiment in which the spring clutch 13 is used, the probability of failure due to deformation of the spring is reduced, and the reliability of the sheet feeding apparatus, and eventually the sheet feeding is increased. Image forming apparatus equipped with a device (for example, a facsimile machine)
Has the effect of increasing the reliability of. <Fourth Embodiment> The first embodiment has shown the mode in which the lifter vertical movement mechanism of the sheet feeding apparatus according to the present invention is applied to the image reading portion of the facsimile machine. It may be applied to an image reading portion of an electronic file or a paper feeding portion of a recording sheet. In this case as well, similar to the first embodiment, a sheet feeding device that does not use expensive clutch means such as a solenoid or an electromagnetic clutch and that is compact and inexpensive is provided, and thus is compact and inexpensive. This has the effect of making it possible to provide copying machines and electronic files.

[0059]

As described above, the sheet feeding apparatus of the present invention urges the sheets on the sheet stacking means toward the feeding means without using expensive clutch means such as solenoids and electromagnetic clutches. Since the sheet pressing means (lifter) is operated by a simple mechanical mechanism and reliable sheet feeding is possible, the size and cost of the apparatus can be reduced.

Further, since the image forming apparatus of the present invention is equipped with the sheet feeding apparatus as described above, the image forming apparatus itself can be made compact and inexpensive.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a sheet feeding device according to a first embodiment of the present invention (when a lifter is descending).

FIG. 2 is a perspective view of a main part showing an operating state of the sheet feeding device (when the lifter is raised).

FIG. 3 is a plan view of the sheet feeding device.

FIG. 4 is a side sectional side view of a main part of a facsimile apparatus using the sheet feeding apparatus.

FIG. 5 is a time chart diagram showing a control state of the sheet feeding device.

FIG. 6 is a side sectional view of a facsimile device.

FIG. 7 is an external perspective view of the facsimile device.

FIG. 8 is a configuration diagram of main parts of a conventional sheet feeding device.

[Explanation of symbols]

1 Document Plate (Sheet Loading Unit) 2 Lifter (Sheet Pressing Unit) 2c Lifter Gear (Input Member, Gear) 4 Second Gear (Gear Device) 6 Arm (Gear Device) 7 First Gear (Gear Device) 10 Separation Roller Shaft (driving shaft) 12 Separation roller (feeding means) 13 Spring clutch (mechanical one-way clutch) 14 Separation pad (separation means) 15c Base side surface (stopper part) 17 Conveying roller (conveying means) 18 Conveying roller (conveying means) 22 Contact sensor (image reading means) 30 Motor (driving source) 111 Image forming unit (image forming means) K Sheet feeding device S Document (sheet)

Claims (8)

[Claims] 1. A sheet stacking unit that stacks sheets, a sheet feeding unit that feeds out the sheets on the sheet stacking unit, and a sheet pressing unit that presses the sheet on the sheet stacking unit against the sheet feeding unit. In the sheet feeding device, the input member attached to the sheet pressing unit and the drive shaft of the feeding unit are connected to each other, and the input member is engaged when the drive shaft rotates in a direction opposite to the sheet feeding direction. And a gear device for releasing the sheet pressing state of the sheet pressing means, and the sheet feeding device. 2. The gear device includes a first gear attached to the drive shaft, a second gear revolving by meshing with the first gear, and rotatably attached to the drive shaft, When the load that acts on the arm that connects the first gear and the second gear to each other is less than or equal to a predetermined value, the arm and the drive shaft are rotated together while the load that acts on the arm is The sheet feeding device according to claim 1, further comprising: a torque limiter that allows relative rotation of the arm and the drive shaft when a predetermined value or more is reached. 3. A support shaft, wherein the gear device is arranged parallel to the drive shaft, and rotates in the same direction as the drive shaft; a first gear attached to the support shaft; and a first gear. A second gear that reciprocates by meshing with the arm, an arm that is rotatably attached to the support shaft and that connects the first gear and the second gear, and a load that acts on the arm is less than or equal to a predetermined value. And a torque limiter for integrally rotating the arm and the support shaft, and permitting relative rotation of the arm with the support shaft when a load acting on the arm is greater than or equal to a predetermined value. The sheet feeding device according to claim 1, wherein: 4. The input member is attached to the sheet pressing means, and when the drive shaft rotates in a direction opposite to a sheet feeding direction, the input member meshes with the second gear and the sheet pressing state of the sheet pressing means. The sheet feeding device according to claim 1, wherein the sheet feeding device is a gear that releases the sheet. 5. When the sheet is fed by the feeding unit, a separating unit that cooperates with the feeding unit to separate the sheets on the sheet stacking unit into sheets one by one is provided. The sheet feeding device according to any one of claims 1 to 4, further comprising a stopper portion that regulates a leading end position of the upper sheet. 6. A one-way clutch for integrally rotating the feeding means and the drive shaft during sheet feeding, and a one-way clutch arranged downstream of the feeding means in the sheet conveying direction,
The sheet feeding device according to any one of claims 1 to 5, further comprising a feeding unit that feeds a sheet at a higher speed than the feeding unit. 7. The method according to claim 1, wherein
2. An image forming apparatus, comprising: the sheet feeding device according to item 1; and an image reading unit that reads image information of a sheet fed by the sheet feeding device. 8. The sheet feeding device according to claim 1, and an image forming unit that forms an image on a sheet fed by the sheet feeding device. An image forming apparatus characterized by being provided.