JP3619018B2 - Sheet supply apparatus and image forming apparatus provided with the apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet feeding apparatus that feeds sheets, and an image forming apparatus such as a copying machine, a laser beam printer, and a facsimile machine including the apparatus.
[0002]
[Prior art]
As shown in FIG. 10, the conventional image forming apparatus can push the cassette 101 out of the image forming apparatus main body 102 by pressing a button 103 disposed in the vicinity of the cassette 101 for storing sheets.
[0003]
At this time, the release operation of each mechanism is performed in the image forming apparatus main body 102. The release operation includes (1) an operation of releasing the sheet nipping state by the conveying roller 123 and the separation roller 124 that separate the sheets fed from the cassette one by one, and (2) the middle plate 115 on which the sheets are stacked. There is an operation for releasing the pushed-up state, and (3) an operation for releasing the holding state of the cassette.
[0004]
The sheet supply device 140 of the image forming apparatus will be described with reference to FIGS.
[0005]
The configuration of the sheet supply apparatus 140 will be described.
[0006]
The interlocking arm 104 shown in FIGS. 11 and 12 is an elongated member, and is integrated with the button 103. A long hole 104 a is formed in the longitudinal direction of the interlocking arm 104. Shafts 105a and 105b that are crimped to a cam holding portion 105 to be described later pass through the long hole 104a. A cam portion 104 c is formed on the side portion of the interlocking arm 104. A return spring 107 is stretched between the spring hooking portion 104 b of the interlocking arm 104 and the spring hooking portion 105 d of the cam holding portion 105.
[0007]
Accordingly, the interlocking arm 104 guides the long hole 104a and the shafts 105a and 105b, and is always pulled by the return spring 107 in the direction protruding from the apparatus main body 102, and the button 103 is moved to the front surface of the image forming apparatus main body 102. Protruding.
[0008]
The cam holding unit 105 is fixed to the image forming apparatus main body 102. The hook release lever 106 is rotatably provided on a shaft 105 c crimped on the cam holding portion 105. Further, the hook release lever 106 is urged to rotate counterclockwise in FIG. 12 by the coil spring 133 so that the rotating end 106 a is always brought into contact with the cam portion 104 c of the interlocking arm 104.
[0009]
The lock lever 108 is a member formed in an L shape in a plan view, and is rotatably provided on a pin 101 a protruding from the cassette 101. The lock lever 108 is pulled so as to rotate clockwise in FIG. 12 by a return spring 109 spanned between a piece 108a of this lever and a spring hooking portion 101b provided in the cassette 101. The rotation is restricted by contacting the stopper pin 108c on the 101. Accordingly, the hook portion 108 b of the lock lever 108 is adapted to engage with the lock lever holding piece 105 e of the cam holding portion 105 fixed to the image forming apparatus main body 102.
[0010]
The lifter release lever 110 shown in FIGS. Supply A shaft 111a provided on the main body 141 of the device 140 is rotatably provided, and is pulled by a return spring 114 so as to always rotate counterclockwise in FIG. 16, and a gear 112 provided at one end 110a is pulled. The lifter motor output gear 113 is meshed with the lifter motor. The gear 113 is rotated counterclockwise in FIG. 16 by a lifter motor (not shown).
[0011]
In FIG. 16, the middle plate 115 is provided so as to be tiltable in the cassette 101 and is configured to stack the sheets S, and is lifted by the pressure plate 116 to a sheet feedable height by a sensor (not shown). It has become.
[0012]
11 and 16, the pressure plate 116 is attached to the shaft 117, and a fan gear 118 is fixed to the other end of the shaft 117. That is, the pressure plate 116, the shaft 117, and the fan gear 118 are configured to rotate integrally.
[0013]
The sector gear 118 is interlocked with the gear 112 via idler gears 122, 121, 120, and 119.
[0014]
In FIG. 12, the distal end 104 d of the connecting arm 104 comes into contact with the inclined cam portion 110 b of the lifter release lever 110.
[0015]
Next, the configuration of the separation roller pairs 123 and 124 for separating and feeding sheets and the related parts will be described.
[0016]
11 and 18, when a plurality of sheets are discharged from the cassette 101 by the pickup roller 125, the conveying roller 123 and the separating roller 124 separate the pair of sheets and convey only one sheet. It is. The separation roller 124 is a so-called retard roller connected to a drive shaft via a torque limiter (not shown).
[0017]
The separation roller arm 126 holds both ends of the separation roller 124, so that the separation roller 124 can be pressed against and separated from the conveyance roller 123. Supply It is provided on a shaft 127 on the main body 141 of the device 140 so as to be swingable.
[0018]
A pressure shaft 128 passes through one end of the separation roller arm 126, and a retard spring 129 is stretched between the center of the pressure shaft 128 and the main body 141. Therefore, the separation roller 124 is brought into pressure contact with the conveying roller 123 with a predetermined pressure by the retard spring 129.
[0019]
11 and 12, the link arm 130 is a member formed in an L shape in plan view, and is a sheet. Supply A shaft 131 projecting from the main body 141 of the device 140 is rotatably provided, pulled by a return spring 132 so as to rotate clockwise in FIG. 11, and abuts against a stopper pin 130c on the main body 141 to restrict rotation. Has been.
[0020]
One end 130a of the link arm 130 is formed in an arc shape, and protrudes from the sheet supply apparatus main body side to the cassette 101 side (projects into the cassette insertion region), and contacts the cam portion 101c when the cassette 101 is inserted. It has become. Further, the other end 130 b is extended to a position where it abuts substantially at the center of the pressure shaft 128.
[0021]
Next, the operation of each unit when the cassette 101 is inserted into the sheet supply apparatus 140 will be described.
[0022]
Since the sheet supply apparatus 140 is incorporated in the image forming apparatus main body 102, inserting the cassette into the sheet supply apparatus is also inserting into the image forming apparatus main body 102.
[0023]
As shown in FIG. 13, when the cassette 101 is inserted into the sheet supply device 140, the link arm 130 is pushed by the cam portion 101 c provided in the cassette 101 and rotates counterclockwise against the spring 132.
[0024]
Then, the other end 130b of the link arm is separated from the pressure shaft 128, and the pressure shaft 128 is pulled by the retard spring 129 and moves from the state of FIG. 19 to the state of FIG. Pressure contact. As a result, the pair of separation rollers 124 and 123 can be separated even if sheets are fed in a superimposed manner.
[0025]
On the other hand, when the cassette 101 is inserted into the sheet supply apparatus, it is detected by the detection means (not shown) that the cassette 101 has been inserted, and a lifter motor (not shown) is started. The rotational force of the lifter motor is transmitted to the fan gear 118 via gears 113, 112, 119, 120, 121 and 122 shown in FIG. The sector gear 118 rotates from the state shown in FIG. 17 to the state shown in FIG. 18, and the intermediate plate 115 is pushed up by the pressure plate 116 to press the sheet S against the pickup roller 125.
[0026]
In addition, the lock lever 108 in FIG. 12 shifts to the state of FIG. 13 together with the cassette 101. Then, the hook portion 108b comes into contact with the lock lever holding piece 105e of the cam holding portion 105, and once moved in the counterclockwise direction, the hook portion 108b returns to its original state and engages with the rear edge of the lock lever holding piece 105e. Therefore, the lock lever 108 is locked to the cam holding portion 105, and as a result, the cassette 101 is securely locked to the image forming apparatus main body 102.
[0027]
Thereafter, the sheet S in the cassette 101 is taken out from the cassette 101 by the pickup roller 125, and is reliably separated into one sheet by the pair of separation rollers 124 and 123, and is conveyed to the image forming unit.
[0028]
Next, the operation of each unit when the cassette 101 is pulled out from the image forming apparatus main body 102 will be described.
[0029]
FIG. 14 is a state diagram of each part when the button 103 is pressed to pull out the cassette 101.
[0030]
When the button 103 is pressed against the return spring 107, the tip 104d of the interlocking arm 104 integral with the button 103 enters toward the inclined cam portion 110b of the lifter release lever 110, and the lifter release lever 110 is returned to the return spring 114 ( 16), it is rotated clockwise in FIG. 16, and the state shown in FIG. 17 is obtained. As a result, the gear 112 is disengaged from the lifter motor output gear 113, the drive to the fan gear 118 is cut off, the sheet S and the intermediate plate 115 are lowered by their own weight, and the pressure contact between the sheet S and the pickup roller 125 is released. Is done. As a result, the release operation (2) is completed.
[0031]
Further, as shown in FIG. 14, when the button 103 is pressed, the cam portion 104 c rotates the hook release lever 106 in the clockwise direction in FIG. 14 against the coil spring 133. One end 106 b of the hook release lever 106 rotates the lock lever 108 counterclockwise against the return spring 109. As a result, the engagement of the hook portion 108b with the lock lever holding piece 105e of the cam holding portion 105 is released.
[0032]
Accordingly, the cassette 101 is pushed out from the image forming apparatus main body 102 by a not-shown push spring. As a result, the releasing operation (3) is completed.
[0033]
When the cassette 101 is pushed out, the pressure contact state between the one end 130a of the link arm 130 and the cam portion 101c of the cassette 101 is released, and the link arm 130 is pulled by the return spring 132 and rotates clockwise.
[0034]
Then, the other end 130b of the link arm 130 rotates until it presses the pressure shaft 128 against the retard spring 129 and abuts against the stopper pin 130c, and as shown in FIG. Release. As a result, the pressure contact state between the transport roller 123 and the transport roller 123 is released, and the release operation (1) is completed.
[0035]
When the finger is released from the button 103, the pushing operation of the cassette 101 is completed, and each component returns to the position shown in FIG. 12, but the lifter release lever 110 is always pulled by the return spring 114, and the lifter The shaft 111a of the release lever 110 and the rotation shaft of the gear 119 are common, and the gear 112 provided on the lifter release lever 110 can roll on the gear 112 while meshing with the gear 119, whereby the gear 112 is lifter motor. It meshes with the output gear 113 again. However, unless the cassette 101 is inserted, the lifter motor is not started, so that the pressure plate 116 is not lifted.
[0036]
[Problems to be solved by the invention]
However, the conventional seat Supply Of the above three releasing operations, the apparatus performs (2) an operation of releasing the state where the middle plate 115 on which the sheets are stacked is released, and (3) an operation of releasing the state of holding the cassette. (1) Since the sheet nipping state is released by the conveying roller 123 and the separating roller 124 for separating the sheets fed from the cassette one by one, the separating roller pairs 123 and 124 are configured. The cassette may be pushed out with the sheet held between them.
[0037]
In such a case, the sheet is torn and the cassette is pulled out, which not only damages the sheet but also leaves a sheet between the pair of separation rollers 123 and 124, which requires time and effort to remove it. Arise.
[0038]
In the worst case, it is not noticed that the sheet remains between the pair of separation rollers 123 and 124, and if the cassette is inserted again, it will cause the sheet to be jammed and take a lot of time for the sheet removing operation. Become.
[0039]
Also such a sheet Supply The image forming apparatus provided with the apparatus may cause a damaged sheet to be sent, and the sheet may be jammed, so that the image forming process cannot be performed smoothly, or the image can be accurately formed on the sheet. Have the problem of not.
[0040]
(the purpose)
Before removing the cassette in which the sheet is stored, the present invention releases the pressure contact state of the separation roller pair, Tearing sheet There is no sheet Supply The object is to provide a device.
[0041]
[Means for Solving the Problems]
The above problem is solved by the following sheet feeding apparatus.
[0042]
A sheet stacking unit that stacks sheets and can be inserted into and removed from the casing, and a holding member provided on one of the casing and the sheet stacking unit to engage the sheet stacking unit with respect to the casing An engagement member provided on the other side for bringing the sheet into an insertion holding state, a separation roller pair for separating the sheet when the sheet is fed from the sheet stacking means inserted in the housing, and the separation roller A pair of roller separating means for separating the pair of rollers; and an external operation that is provided on the casing and moves by an external operation to move the roller pair separating means to separate the rollers; And an external operation member to be removed from the member.
[0043]
The external operation member includes a first operating piece that operates the roller pair separating means and a second operating piece that operates the engaging member.
[0044]
The first working piece and the second working piece are cams.
[0045]
The external operation member is biased in a protruding direction from the housing by a return spring.
[0046]
The external operation member is a long member, and a button is provided at a portion protruding from the housing.
[0047]
The engaging member is a lock lever that is urged to rotate in one direction, and includes a stopper pin that engages with the holding member at a rotation end of the lock lever.
[0048]
The roller pair separation means holds a rotatable link that is rotated by the external operation member, and a pressure shaft that contacts the link at one end, and a rotation shaft of one roller of the separation roller pair at the other end. And a pair of arms which are rotatable and spaced apart from each other with the middle part as a rotation center.
[0049]
Lifter member for stacking the sheet and moving up and down the intermediate plate provided in the sheet stacking means, lifter driving means for driving the lifter member, and canceling transmission of driving force of the lifter driving means to the lifter member A lifter drive release lever, and a first operating piece of the external operation member operates the lifter drive release lever and the roller pair separating means.
[0050]
The roller pair separating means provided in the casing, causing the roller pair separating means to perform the separating operation of the rollers in conjunction with the drawing operation of the sheet stacking means, and in the state where the sheet stacking means is pulled out. And a roller pair separation assisting means for causing the roller pair separation means to maintain the separated state of the rollers by displacing the roller to a position not subjected to the action of the external operation member.
[0051]
The roller pair separation assisting means is a link arm that is urged to rotate by a return spring in a direction that contacts the link of the roller pair separation means and presses the link against the pressure shaft.
[0052]
The above problem is solved by the following image forming apparatus.
[0053]
One of the above-described sheet supply apparatuses and an image forming unit that forms an image on the sheet sent from the sheet supply apparatus are provided.
[0054]
(Function)
When the sheet stacking unit is inserted into the housing, the engaging member is engaged with the holding member, and the insertion state of the sheet stacking unit is held. The sheet is sent out from the sheet stacking means. When the sheets are sent out in an overlapping manner, they are separated by a pair of separation rollers and only one sheet is supplied.
[0055]
When the external operation member is operated to take out the sheet stacking means, first, the roller pair separating means is actuated to separate the rollers of the separation roller pair. Thereafter, the engaging member is removed from the holding member, the insertion holding state of the sheet stacking unit is released, and the sheet stacking unit can be removed from the housing.
[0056]
Thus, since the sheet stacking unit can be taken out after the rollers of the separation roller pair are separated from each other, the sheet is not torn while being sandwiched between the pair of separation rollers.
[0057]
In addition, when the external operation member is operated, the lifter drive release member is also actuated to cut off the driving force to the lifter that raises and lowers the sheet stacking body. Therefore, the lifter is driven by the weight of the sheet and the weight of the lifter. Lower and leave the sheet stack. Therefore, the lifter does not interfere with the sheet stacking unit when the sheet stacking unit is taken out.
[0058]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0059]
In addition, about the same part as the past, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
[0060]
(Image forming device)
First, the copying machine 10, which is an image forming apparatus in which the sheet supply device 240 is incorporated, will be schematically described with reference to FIG.
[0061]
The configuration will be described.
[0062]
The copying machine 10 includes a copying machine main body 102 and an automatic document feeder 11 provided on the copying machine body 102.
[0063]
On the upper part of the copying machine main body 102, a document table glass 5 is provided. Below the platen glass 5, an exposure lamp 6a, a scanning mirror 6b, a zoom lens 6c, and the like constituting an optical system 6 as an image reading unit are disposed.
[0064]
Below the optical system 6, a photosensitive drum 7a, a high voltage unit 7b, a developing device 7e, a transfer charging device 7f, a separation charging device 7g, and the like constituting the image forming unit 7 are disposed. A conveyance belt 15 that conveys the sheet and a fixing device 16 are arranged downstream of the image forming unit 7. Below the photosensitive drum 7a, a cassette 101, a pickup roller 125, a conveyance roller 123, a separation roller 124, and conveyance rollers 12a, 12b, 12c, and 12d, which constitute a sheet supply device 240, are disposed.
[0065]
The operation will be described.
[0066]
When a document is set on the automatic document feeder 11 and the copying machine 10 is started, the documents are sequentially fed onto the document glass 5 one by one. The optical system 6 illuminates the original on the platen glass 5 with the exposure lamp 6a, and irradiates the photoreceptor 7a with reflected light from the original by the scanning mirror 6b and the zoom lens 6c. The photoconductor 7a is rotated by a main motor (not shown), and is corona-charged by the high-voltage unit 7b. As a result, an image of the original is formed as an electrostatic latent image on the photoconductor 7a. This electrostatic latent image is developed by the developing device 7a and visualized as a toner image.
[0067]
On the other hand, when the sheet is sent out from the cassette 101 of the sheet supply device 240 by the pickup roller 125 and the sheets are sent out by being overlapped, the sheets are separated one by one by the conveying roller 123 and the separation roller 124, and the sheets are separated. It is sent to the photoreceptor 7a by the transport rollers 12a, 12b, 12c, and 12d. Then, the toner image is transferred to the sheet by the transfer charger 7f and the separation charger 7g. Thereafter, the sheet is conveyed by the conveyance belt 15 and sent to the fixing device 16. The toner image is permanently fixed on the sheet by the high temperature and high pressure of the fixing device 16. Finally, the sheet is discharged onto the discharge tray 17.
[0068]
(Sheet feeding device)
The configuration will be described.
[0069]
In FIG. 2, the link arm 1 is formed in an L shape in plan view, is rotatably provided on a shaft 131 projecting from a main body 141 (see FIG. 1) of the sheet feeding device 240, and a return spring 132. Is pulled to rotate clockwise.
[0070]
In FIG. 3, one end 1 a of the link arm 1 is formed in an arc shape, protrudes from the main body 141 of the sheet supply device 240 toward the cassette 101, and comes into contact with the cam portion 101 c of the inserted cassette 101. Yes.
[0071]
In FIG. 2, the separation roller release link 2 is rotatably provided on the shaft 131 and is restricted by a stopper pin 2 d that protrudes from the main body 141 of the sheet supply device 240.
[0072]
In FIG. 3, the front end 2b of the separation roller release link 2 extends almost to the center of the pressure shaft 128 and comes into contact with the center. A locking piece 2 c that engages with the locking piece 1 b of the link arm 1 is provided at an intermediate portion of the separation roller release link 2.
[0073]
As shown in FIG. 7, the lifter release lever 3 is rotatably provided on the shaft 111 a of the main body 141 of the sheet feeding device 240, and is always pulled by the return spring 114 so as to rotate counterclockwise. .
[0074]
A projecting portion 3c projecting toward the end portion 2a of the separation roller releasing link 2 is provided below the shaft 111a, which is the rotation center of the lifter releasing lever 3, and can come into contact with the end portion 2a. Yes.
[0075]
The operation will be described.
[0076]
FIG. 3 is a diagram illustrating a state where the cassette 101 is not completely inserted into the sheet supply apparatus 240.
[0077]
The link arm 1 is pulled by the return spring 132 so as to rotate clockwise, and the separation roller release link 2 is urged to rotate clockwise via the locking piece 1b and the locking piece 2c to release the separation roller. The tip 2b of the link 2 is brought into pressure contact with the pressure shaft 128. The rotation of the link arm 1 and the separation roller release link 2 is restricted by the link arm 1 abutting against the stopper pin 2d.
[0078]
On the other hand, the pressure shaft 128 tends to be pulled by the retard spring 129 against the pressure contact force of the tip 2b of the separation roller release link 2, but the pressure contact force of the tip 2b of the separation roller release link 2 is stronger. The separation roller 124 on the separation roller arm 126 provided with the pressure shaft 128 is not moved, and is separated from the conveying roller 123 in the same manner as in the state shown in FIG. Stays.
[0079]
As shown in FIG. 4, when the cassette 101 is inserted into the sheet feeding device 240, the link arm 1 is pushed by the cam portion 101 c of the cassette 101 and rotated counterclockwise against the spring 132. At the same time, the locking piece 1 b of the link arm 1 moves away from the separation roller release link 2.
[0080]
The separation roller release link 2 becomes rotatable. As a result, the pressure shaft 128 presses the tip 2b of the separation roller release link 2 while being pulled by the retard spring 129, and rotates the separation roller release link 2 counterclockwise. In addition, the pressing shaft 128 presses the separation roller 124 against the conveying roller 123 almost simultaneously so that the pair of separation rollers 124 and 123 can be separated.
[0081]
When the cassette 101 is inserted into the sheet supply device 240, it is detected by the detection means (not shown) that the cassette 101 has been inserted, and a lifter motor (not shown) is started. The rotational force of the lifter motor is transmitted to the fan gear 118 via gears 113, 112, 119, 120, 121 and 122 shown in FIG. The sector gear 118 rotates from the state shown in FIG. 8 to the state shown in FIG. 7, and the intermediate plate 115 is pushed up by the pressure plate 116 to bring the sheet S into pressure contact with the pickup roller 125.
[0082]
In the lock lever 108 in FIG. 5, the hook portion 108 b engages with the lock lever holding piece 105 e of the cam holding portion 105, and the cassette 101 is securely locked to the sheet feeding device 240.
[0083]
FIG. 5 is a diagram showing a state in which the button 103 is pressed to pull out the cassette 101.
[0084]
When the button 103 is pushed against the return spring 107, the tip 104d of the interlocking arm 104 integral with the button 103 enters toward the inclined cam portion 3b of the lifter release lever 3, and the lifter release lever 3 is returned to the return spring 114 ( Rotate clockwise in FIG. 8 against (see FIG. 8). As a result, the gear 112 is disengaged from the lifter motor output gear 113, the drive to the fan gear 118 is cut off, the sheet S and the intermediate plate 115 are lowered by their own weight, and the pressure contact between the sheet S and the pickup roller 125 is released. Is done.
[0085]
Furthermore, since the protrusion 3a of the lifter release lever 3 also moves leftward in FIG. 4, as shown in FIG. 5, the protrusion 3a presses the end 2a of the separation roller release link 2 to release the separation roller. The link 2 is rotated clockwise. Then, the tip 2 b pushes the pressure shaft 128 against the retard spring 129, the separation roller arm 126 shown in FIG. 1 rotates, and the separation roller 124 is separated from the transport roller 123.
[0086]
In addition, when the button 103 is pressed, in FIG. 5, the cam portion 104 c rotates the hook release lever 106 in the clockwise direction against the coil spring 133, and one end 106 b of the hook release lever 106 causes the lock lever 108 to move. Turn counterclockwise. Therefore, the hook portion 108b is disengaged from the lock lever holding piece 105e, and the cassette 101 is pushed forward from the sheet supply device by a not-shown push spring. FIG. 6 shows this state.
[0087]
At this time, the pressure contact between the one end 1a of the link arm 1 and the cam portion 101c of the cassette 101 is released. Press. The pressure shaft 128 moves while being pressed against the retard spring 129, rotates the separation roller arm 126 shown in FIG. 1, and separates the separation roller 124 from the transport roller 123.
[0088]
Therefore, as shown in FIG. 3, even if the finger is released from the button 103, the traction force of the return spring 132 causes (1) the pressure contact between the conveying roller 123 and the separation roller 124 to separate the sheets fed from the cassette one by one. The state can be released and held.
[0089]
Of course, the state (2) in which the state where the middle plate 115 on which sheets are stacked is released is released and the state (3) where the cassette is held are released.
[0090]
The gear 112 and the lifter motor output gear 113 are engaged again, but unless the cassette 101 is inserted, it does not rotate and push the intermediate plate 115 up by the pressure plate 116.
[0091]
【The invention's effect】
In the sheet feeding apparatus of the present invention, when the cassette is taken out from the housing, the pressure contact between the separation roller pairs can be released before releasing the holding state of the cassette. Therefore, when the cassette is pulled out, the sheet is sandwiched between the separation roller pairs. This prevents the sheet from being torn and prevents damage to the sheet.
[0092]
In addition, the image forming apparatus provided with such a sheet supply device does not form an image on a damaged sheet, can form a high-quality image on the sheet, and prevents sheet jamming. Is done.
[Brief description of the drawings]
FIG. 1 is a perspective view of a sheet feeding apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view of main components of the sheet feeding apparatus according to the embodiment of the present invention.
FIG. 3 is a plan view of the sheet supply apparatus of FIG. 1;
FIG. 4 is a plan view of a state in which a cassette is pushed into the sheet supply apparatus.
FIG. 5 is a plan view when the cassette is taken out from the sheet supply apparatus.
FIG. 6 is a plan view immediately after the cassette is pushed out of the sheet supply apparatus.
FIG. 7 is a state diagram in which a sheet is pressed against a pickup roller.
FIG. 8 is a diagram illustrating a state in which the pickup roller is separated from the sheet.
FIG. 9 is a schematic front cross-sectional view of an image forming apparatus including a sheet supply device.
FIG. 10 is an external perspective view of the image forming apparatus with the cassette pulled out.
FIG. 11 is a perspective view of a conventional sheet supply apparatus.
12 is a plan view of the sheet supply apparatus of FIG. 11. FIG.
FIG. 13 is a plan view showing a state in which a cassette is pushed into a conventional sheet supply apparatus.
FIG. 14 is a plan view when the cassette is taken out from the conventional sheet supply apparatus.
FIG. 15 is a plan view immediately after the cassette is pushed out from the conventional sheet feeding apparatus.
FIG. 16 is a state diagram in which a sheet is pressed against a pickup roller.
FIG. 17 is a diagram illustrating a state in which the pickup roller is separated from the sheet.
FIG. 18 is a state diagram in which a pair of separation rollers is in pressure contact with each other.
FIG. 19 is a state diagram where the separation roller pairs are separated from each other.
[Explanation of symbols]
S sheet
1 Link arm (roller pair separation assisting means)
1a one end
1b Locking piece
1c The other end
2 Separation roller release link (Roller pair separation means, link)
2a end
2c Locking piece
2b Tip
2d stopper pin
3 Lifter release lever
3a protrusion
3b Inclined cam part
7 Image forming section
7a Photosensitive drum (image forming unit)
7b High pressure unit (image forming unit)
7e Developer (image forming unit)
7f Transfer charger (image forming unit)
7g Separation charger (image forming unit)
10 Copying machine (image forming device)
101 Sheet loading cassette (sheet loading means)
101a pin
101b Spring hook
101c Cam part
102 Image forming apparatus main body, sheet supply apparatus main body (housing)
103 buttons
104 Interlocking arm (external operation member)
104c Cam part (second operating piece, cam)
104d Tip (first working piece, cam)
105 Cam holder
105e Lock lever holding piece (holding member)
107 Return spring
108 Lock lever (engaging member)
108c Stopper pin
112 Gear (lifter drive means)
113 Lifter motor output gear (lifter drive means)
114 Return spring
115 Middle plate
116 Pressure plate (lifter member)
118 Fan gear (lifter drive means)
119 to 122 idler gear (lifter drive means)
123 Conveyance roller (separation roller pair)
124 Separation roller (separation roller pair)
125 Pickup roller
126 Separation roller arm (roller pair separation means, arm)
127 shaft (roller pair separating means)
128 Pressure shaft (Roller pair separation means)
129 retard spring (roller pair separation means)
132 Return spring (roller pair separation assisting means)
141 Sheet feeder main body
240 Sheet feeder

Claims (11)

A sheet stacking means that stacks sheets and can be inserted into and removed from the housing;
An engagement member provided on the other side that engages with a holding member provided on one of the housing and the sheet stacking unit to bring the sheet stacking unit into an inserted and held state with respect to the housing;
A pair of separation rollers for separating the sheets when the sheets are double-fed from the sheet stacking means inserted in the housing;
Roller pair separating means for separating the rollers of the separation roller pair;
An external operation member that is provided in the casing and moves by an external operation, operates the roller pair separation means to separate the rollers, and then removes the engagement member from the holding member;
A sheet feeding apparatus comprising: 2. The sheet feeding apparatus according to claim 1, wherein the external operation member includes a first operating piece that operates the roller pair separating unit and a second operating piece that operates the engaging member. . The sheet feeding device according to claim 2, wherein the first working piece and the second working piece are cams. The sheet supply apparatus according to claim 1, wherein the external operation member is urged in a protruding direction from the housing by a return spring. 5. The sheet feeding apparatus according to claim 1, wherein the external operation member is a long member, and a button is provided at a portion protruding from the casing. 6. The engagement member is a lock lever that is urged to rotate in one direction, and includes a stopper pin that engages with the holding member at a rotation end of the lock lever. Sheet feeding device. The roller pair separation means holds a rotatable link that is rotated by the external operation member, and a pressure shaft that contacts the link at one end, and a rotation shaft of one roller of the separation roller pair at the other end. 2. A sheet feeding apparatus according to claim 1, further comprising a pair of arms that are spaced apart from each other and that hold both ends of the sheet and that are rotatable about an intermediate portion. A lifter member that stacks the sheets and moves up and down an intermediate plate provided in the sheet stacking means;
Lifter driving means for driving the lifter member;
A lifter drive release lever that releases transmission of the drive force of the lifter drive means to the lifter member,
4. The sheet feeding apparatus according to claim 2, wherein the first operating piece of the external operation member operates the lifter drive release lever and the roller pair separating means. 5. The roller pair separating means provided in the casing, causing the roller pair separating means to perform the separating operation of the rollers in conjunction with the drawing operation of the sheet stacking means, and in the state where the sheet stacking means is pulled out. 2. The sheet according to claim 1, further comprising: a roller pair separation assisting unit that displaces the roller to a position not affected by the external operation member and causes the roller pair separation unit to maintain a separation state between the rollers. Feeding device. 8. The roller pair separation assisting means is a link arm that is rotationally biased by a return spring in a direction that contacts the link of the roller pair separation means and presses the link against the pressure shaft. The sheet supply apparatus according to 1. A sheet feeding device according to any one of claims 1 to 10,
An image forming unit that forms an image on the sheet sent from the sheet supply apparatus;
An image forming apparatus comprising:

Images