JP7151235B2 - Paper feeder and image forming device - Google Patents

Description

The present invention relates to a sheet feeding device and an image forming apparatus.

2. Description of the Related Art Image forming apparatuses such as printers, copiers, and facsimiles are equipped with a paper feeding device (supplying device) that conveys paper. This paper feeder employs a mechanism in which papers are stacked on a bottom plate that can be moved up and down, and the bottom plate is lifted and pressed against paper feed rollers to convey the paper.

Specifically, the paper feeding roller is driven via a single electromagnetic clutch, and as a means for moving the bottom plate up and down, (a) the user operates the lock lever member to raise the bottom plate, or (b) the bottom plate A known technique is to drive a cam member capable of coming into contact with the bottom plate through a separate dedicated electromagnetic clutch to push down the bottom plate to a lowered position and raise the bottom plate after the paper is set.

As another technique, Patent Document 1 discloses that paper feed rollers are half-moon shaped (one side contacts the bottom plate but the other side does not) and are driven via an electromagnetic clutch that stops after one rotation to feed paper. A transport arrangement is disclosed. Further, in Japanese Patent Application Laid-Open No. 2002-200002, a paper feed roller shaft and a cam member that pushes down a bottom plate are connected by a gear, and the gear is rotated forward and backward by a dedicated drive motor to press the paper against the paper feed roller. is disclosed.

Further, Japanese Patent Application Laid-Open No. 2002-200000 discloses a configuration in which rotation of a paper feed roller releases a stopper member of a bottom plate to raise the bottom plate.

However, in the configuration of (a) and Japanese Patent Application Laid-Open No. 2002-200032, there is a possibility that paper skew or paper jam may occur due to missetting of paper due to user's erroneous operation. Moreover, in the configuration of (b) and Patent Document 2, special parts (clutch, motor, etc.) are separately required, which causes problems of cost increase and space saving. Furthermore, the configuration of Patent Document 1 has a problem that registration correction (alignment of the leading edge of the paper) cannot be performed.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet feeding device that does not require the user to lift and lower a bottom plate, is relatively inexpensive, and is capable of correcting recording materials.

The above-mentioned problems are provided by a drive shaft that rotates the paper feed roller, a bottom plate on which the recording material is placed , an urging means that pushes up the bottom plate, and a bottom plate that contacts the bottom plate and resists the urging force of the urging means. and a lever member interlocking with driving of the drive shaft , wherein by driving the drive shaft, the cam member interlocks with the lever member to move the The bottom plate is lifted by the urging means to press the recording material against the paper feeding roller, and the rotation of the paper feeding roller pushes the recording material to a register downstream of the paper feeding roller in the conveying direction. In a sheet feeding device in which the sheet feeding roller is temporarily stopped when it abuts against the roller pair, then the sheet feeding roller and the registration roller pair are rotated, and the bottom plate is lowered by the cam member, the lever comprising: A standby position sensor for detecting the phase of the member is provided, and the standby position sensor outputs ON when the lever member is at the predetermined standby position, and outputs OFF when the lever member is not at the standby position. When the standby position sensor outputs OFF during initial operation, the drive shaft continues to rotate until the standby position sensor outputs ON twice. solved by the device.

In the sheet feeder of the present invention, the cam member moves the bottom plate up and down, so the user does not need to move the bottom plate up and down. Therefore, it is possible to prevent missetting of the recording material due to an erroneous operation by the user. Moreover, since both the cam member and the paper feed roller are driven by the paper feed roller shaft, the cost is relatively low. Furthermore, registration correction can also be performed.

1 is a perspective view of an image forming apparatus according to an embodiment of the invention; FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention; FIG. 1 is a perspective view of a manual sheet feeding unit according to one embodiment of the present invention; FIG. 1 is a configuration diagram of a manual sheet feeding unit according to an embodiment of the present invention; FIG. 5 is an enlarged view showing configurations of a lever member and a cam member in FIG. 4; FIG. FIG. 5 is a configuration diagram showing a standby state of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. 4; FIG. 5 is a configuration diagram showing a paper feeding start operation of the manual paper feeding unit when viewed from the direction of arrow B1 in FIG. 4; FIG. 5 is a configuration diagram showing separation and conveyance of a recording material in a manual paper feeding unit as viewed from the direction of arrow B1 in FIG. 4; FIG. 5 is a configuration diagram showing a registration correction operation of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. 4; FIG. 5 is a configuration diagram showing a bottom plate standby state of the manual sheet feeder viewed from the direction of arrow B1 in FIG. 4 ; FIG. 5 is a configuration diagram showing jam processing of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. 4; FIG. 5 is a configuration diagram showing an irregular stop state (No. 1) of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. 4 ; FIG. 5 is a configuration diagram showing an irregular stop state (No. 2) of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. 4 ; FIG. 5 is a configuration diagram showing a modification of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. 4;

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a perspective view of an image forming apparatus according to one embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of the same apparatus. A document reading section (scanner section) 5 is installed on the upper part of the main body of the image forming apparatus 1 of FIG. 1, and an operation panel 6 is arranged on the front side. The document reading unit 5 includes a contact glass 5a as a document table on which the document shown in FIG. 2 is placed, an illumination light source 5b for illuminating the document, a first mirror 5c and a second mirror for reflecting light reflected from the document. 5d and a third mirror 5e. It also has an image forming lens 5f for forming an image of reflected light from the document, and an image sensor 5g such as a CCD as reading means which is installed at the image forming position and reads the document image.

Above the document reading section 5, a pressure plate for pressing the document placed on the contact glass 5a, or an automatic document feeder (ADF) for automatically feeding the document onto the contact glass 5a may be provided.

An image forming section 2 is provided in the central portion of the apparatus main body. The image forming unit 2 includes four image forming units for forming yellow (Y), cyan (C), magenta (M), and black (B) images, and an endless belt-shaped intermediate transfer member (hereinafter referred to as an intermediate transfer member). An intermediate transfer belt unit 17 having an intermediate transfer belt 17a is installed. An optical writing device 13 is installed below these four image forming units.

Each image forming unit has the same configuration, and includes photosensitive drums 11Y, 11C, 11M, and 11B as image carriers. Dedicated charging devices 12Y, 12C, 12M and 12B, developing devices 14Y, 14C, 14M and 14B, primary transfer rollers 15Y, 15C, 15M and 15B, and cleaning devices 16Y, 16C, 16M and 16B are installed around them. ing.

The optical writing device 13 has one deflector in the center, and the one deflector distributes the light beams from the four light sources into four systems, deflects and scans them, and applies them to the four photosensitive drums 11Y, 11C, 11M, and 11B. Write a latent image.

Specifically, the optical writing device 13 includes four laser diode (LD) light sources prepared for each color, an optical system for collimating the laser beams emitted from the light sources, a polygon mirror (rotating polygon mirror), and a and a deflector (polygon scanner) composed of a polygon motor. It also has a scanning/imaging lens such as an fθ lens installed in the optical path of each light source, and an optical system comprising a correcting lens, a mirror, and the like.

The laser beams emitted from the laser diodes according to the image information of each color are deflected and scanned by the polygon scanner, and the photosensitive drums 11Y, 11C, 11M, and 11B of each color are irradiated with the laser beams.

Toner bottles 32Y, 32C, 32M, and 32B for supplying toner to the developing devices 14Y, 14C, 14M, and 14B of the respective image forming units are provided between the image forming section 2 and the internal paper discharge section 4. there is The toner bottles 32Y, 32C, 32M, and 32B are filled with yellow (Y), cyan (C), magenta (M), and black (B) toners from the left in FIG. From here, the toner of each color is replenished to the developing devices 14Y, 14C, 14M, and 14B of each color by a predetermined replenishment amount through a conveying path.

The intermediate transfer belt 17a of the intermediate transfer belt unit 17 is supported by a driving roller, a driven roller and a primary transfer roller, and is rotated in the direction of the arrow in FIG. A secondary transfer roller 22 is provided on the right side of the intermediate transfer belt 17a, and an intermediate transfer belt cleaning device 18 is provided on the left side of the intermediate transfer belt 17a.

In a paper feed section 3 at the bottom of the apparatus main body, two stages of paper feed cassettes 3a and 3b containing recording materials S as recording media are installed. The recording material S is fed from one of the paper feed cassettes by the paper feeders 19a and 19b, and is fed toward the registration roller pair 21 via the transport rollers 20a and 20b. Further, the recording material S fed to the registration roller pair 21 is sent out toward the secondary transfer roller 22 at a predetermined timing.

A manual paper feeder 39 is provided on the side of the apparatus, and the recording material S from the manual paper feeder 39 is fed toward the registration roller pair 21 by a paper feed roller 47 .

A fixing unit 9 is installed above the secondary transfer roller 22 . The fixing unit 9 includes, for example, a fixing belt 9c supported by a fixing roller 9a and a heating roller 9b, and a pressure roller 9d in pressure contact with the fixing belt 9c. Further, above the fixing unit 9, a conveying roller 23 for conveying and discharging the paper toward the internal paper discharging section 4 and a paper discharging roller 24 are provided. Furthermore, there are provided a switching claw 25 for switching the conveying path during double-sided printing, a reversing conveying roller 26 for reversing the direction of the paper in a switchback manner, and a reversing conveying path 27 .

The sheet temporarily stacked on the reversing transport path 27 is reversed in direction by the reversing transport roller 26, transported on the double-sided transport path by the transport rollers 28 and 29, and re-fed to the registration roller pair 21. .

Next, the configuration of the manual paper feeding unit 39 as a paper feeding device having a paper separation mechanism according to one embodiment of the present invention will be described.

FIG. 3 is a perspective view of a manual paper feeder according to one embodiment of the present invention. As shown in FIG. 3, the manual paper feeding section 39 has a bottom plate 41 as a paper stacking section on which recording materials are placed, and paper feeding means for feeding the recording materials. It is provided on the right side of the main body of the image forming apparatus 1 shown.

Specifically, the manual feed unit 39 includes a manual feed cover 40, a bottom plate 41 rotatably attached to the manual feed cover 40 via a rotation shaft, and attached to the manual feed cover 40 to regulate the width direction of the recording material. Side fences 42a and 42b are provided. Here, a pressure spring is provided between the bottom plate 41 and the manual feed cover 40 as an urging means for pushing up the bottom plate 41 . In addition, the side fences 42a and 42b are configured to open and close evenly on the left and right sides. Note that the side fences 42 a and 42 b may be attached to the bottom plate 41 .

The manual feed cover 40 is attached to the image forming apparatus 1 in such a manner that it can be opened and closed. Also, when not in use, it can be closed and stored.

FIG. 4 is a configuration diagram of a manual sheet feeding unit according to one embodiment of the present invention. As shown in FIG. 4, the manual paper feeder 39 includes a paper feed roller shaft 45 which is a drive shaft extending in a direction perpendicular to the paper feed direction (arrow direction). A paper feed roller 47 is rotatably attached (supported) to the paper feed roller shaft 45 via a one-way clutch 46 . When the paper feed roller shaft 45 rotates in the arrow A1 direction in the drawing, the paper feed roller 47 also rotates in the same direction (arrow A1 direction) to convey the recording material in the paper feed direction. Further, even if the paper feed roller shaft 45 stops, the one-way clutch 46 allows the paper feed roller 47 to rotate in the same direction (arrow A1 direction).

Cam members 48a and 48b are attached to both ends of the paper feed roller shaft 45 so as to be rotatable with respect to the paper feed roller shaft 45, respectively. That is, the paper feed roller shafts 45 are loosely inserted into the holes of the cam members 48a and 48b, and the cam members 48a and 48b are not rotated by the paper feed roller shafts 45. As shown in FIG. Lever members 49a and 49b are attached to the paper feed roller shaft 45 on the outside of the cam members 48a and 48b, respectively. That is, the paper feed roller shafts 45 having different shapes from the holes are inserted into the holes of the lever members 49a and 49b, and the lever members 49a and 49b are rotated together with the paper feed roller shafts 45. FIG.

5 is an enlarged view showing the configuration of the lever member and the cam member in FIG. 4. FIG. As shown in FIG. 5 , the lever member 49 a includes a rotary shaft hole portion 65 , a lever portion 66 extending vertically from the rotary shaft hole portion 65 , and a lever portion 66 provided at the tip of the lever portion 66 and parallel to the rotary shaft hole portion 65 . and a projecting portion 50a protruding toward the end. On the other hand, the cam member 48a has a rotary shaft hole portion 67 and a cam portion 68 extending vertically from the rotary shaft hole portion 67 .

The lever member 49a and the cam member 48a are mounted adjacent to each other on the same drive shaft (paper feeding roller shaft 45). It can abut against the cam portion 68 .

With this configuration, the lever member 49a can rotate in conjunction with the cam member 48a when it rotates. The cam portion 68 of the cam member 48a can contact the bottom plate 41 during rotation. This series of actions will be described later in detail.

Although the cam member 48a and the lever member 49a are shown in FIG. 5, the cam member 48b and the lever member 49b have the same configuration. Moreover, FIG. 5 is an example. The lever member 49a may have a shape other than this as long as it can rotate in conjunction with the cam member 48a when it rotates itself.

Returning to FIG. 4, the description is continued. The cam members 48a and 48b on the paper feeding roller 47 side are restricted from moving in the axial direction by using E-ring restricting members. The lever members 49a and 49b have a D-shaped cross-section of the paper feed roller shaft 45, and the lever members 49a and 49b are also inserted into the paper feed roller shaft 45 after similarly forming a D-cut groove shape. . Therefore, as the paper feed roller shaft 45 rotates, the lever members 49a and 49b also rotate. E-rings are fastened to the opposite sides of the lever members 49a and 49b with respect to the sheet feeding roller 47, respectively.

With various parts attached to the paper feed roller shaft 45 , the paper feed roller shaft 45 is inserted into the hole 70 of the body frame of the image forming apparatus 1 via the sliding bearing 71 . An E-ring is attached to the end of the paper feed roller shaft 45 inserted into the sliding bearing 71 .

Further, the manual paper feeding unit 39 includes a phase detection filler 52 and a first electromagnetic clutch 53 on the right side of the paper feed roller shaft 45 attached to the body frame and on the inner side of the image forming apparatus. E-rings are fastened to the paper feed roller shafts 45 on both sides.

Further, the manual paper feeding unit 39 includes a standby position sensor 54 that detects the phase of the phase detection filler 52 , an idler gear 55 that meshes with the gear of the first electromagnetic clutch 53 , and a motor 56 that drives the idler gear 55 . The rotation of the motor 56 causes the idler gear 55 to rotate, and the first electromagnetic clutch 53 is turned on (voltage is applied), thereby rotating the paper feed roller shaft 45 .

A second electromagnetic clutch 57 is attached to the registration roller pair 21 to which the recording material S is supplied, and the registration roller pair 21 is rotated by a separate motor 58 when the second electromagnetic clutch 57 is ON (voltage applied). . Also, the first electromagnetic clutch 53 , the second electromagnetic clutch 57 , the motors 56 and 58 , etc. are controlled by a control device provided in the image forming apparatus 1 .

Next, a series of sheet feeding operations of the manual sheet feeding section 39 configured as described above and registration correction will be described.

(standby state)
FIG. 6 is a configuration diagram showing the standby state of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. For easy understanding, the paper feed roller 47 is drawn with a dashed line. In the subsequent drawings, the same reference numerals are given to the same parts as in FIGS. 3 to 5, and detailed description thereof will be omitted. For convenience of explanation, only one side (cam member 48a, lever member 49a, etc.) is shown, but the other side (cam member 48b, lever member 49b, etc.) has the same configuration unless otherwise specified.

As shown in FIG. 6 , a pressure spring 59 is provided between the manual feed cover 40 and the bottom plate 41 to push up the bottom plate 41 . The cam member 48 a vertically abuts on the bottom plate 41 to move the bottom plate 41 to the lowest position against the biasing force of the pressure spring 59 . In this standby state, the user can place (set) the recording material S on the bottom plate 41 .

The position (phase) of the lever member 49a in this standby state is called a standby position. The manual paper feeding unit 39 can determine whether or not the lever member 49a is at the standby position by the standby position sensor 54 that detects the phase of the phase detection filler 52 (see FIG. 4). In this embodiment, the standby position sensor 54 outputs ON when the lever member 49a is at the predetermined standby position, and outputs OFF when the lever member 49a is not at the standby position.

(Start feeding)
7A and 7B are configuration diagrams showing the paper feeding start operation of the manual paper feeding unit as viewed from the direction of arrow B1 in FIG. During the paper feeding operation (printing operation), the rotation of the paper feeding roller shaft 45 is controlled by turning ON/OFF the first electromagnetic clutch 53 (see FIG. 4).

When the first electromagnetic clutch 53 is turned on, the paper feed roller shaft 45 in FIG. 7 rotates clockwise in the drawing. When the projection 50a of the rotating lever member 49a comes into contact with the cam member 48a, the cam member 48a moves away from the bottom plate 41 in conjunction with the lever member 49a. The bottom plate 41 is urged by the pressure spring 59 to move upward, and the recording material S placed on the bottom plate 41 is brought into contact with the paper feeding roller 47 and pressed. Along with the rotation of the paper feed roller shaft 45, the paper feed roller 47 also rotates to send out the recording material S in the paper feed direction.

(Recording Material Separation and Conveyance)
FIG. 8 is a configuration diagram showing recording material separation and conveyance in the manual paper feeding unit as viewed from the direction of arrow B1 in FIG. The recording material S transported by the paper feed roller 47 is transported between the paper feed roller 47 and the separation pad 60, separated into one upper sheet by the paper feed roller 47 and the separation pad 60, and further separated by the paper feed roller 47. Rotate and transport. Here, the lever member 49a and the cam member 48a are also rotated in conjunction with the rotation of the paper feed roller 47. As shown in FIG. The separation pad 60 is pressed against the paper feed roller 47 by a pressure spring 61 . Therefore, the recording material S is continuously conveyed even after the pressure from the bottom plate 41 is released.

(registration correction operation)
9A and 9B are configuration diagrams showing the registration correction operation of the manual sheet feeder viewed from the direction of arrow B1 in FIG. A registration sensor (not shown) is provided in front of the registration roller pair 21 . The manual paper feeding unit 39 further conveys the recording material S, and after a predetermined time has passed since the registration sensor detects the recording material S, the first electromagnetic clutch 53 is turned off. As a result, the leading edge of the recording material S abuts against the nip portion of the registration roller pair 21, which is the supply destination, to generate a predetermined slack (ΔS). At the same time, by temporarily stopping the paper feed roller shaft 45 (turning off the first electromagnetic clutch 53), the leading edge of the recording material S is aligned at the nip portion of the pair of registration rollers 21 (registration correction).

After the registration correction, the pair of registration rollers 21 is rotated (the second electromagnetic clutch 57 is turned on), and the paper feed roller shaft 45 is rotated (the first electromagnetic clutch 53 is turned on), so that the recording material S is transferred to the image forming apparatus 1. to the image forming section.

(Bottom plate standby state)
FIG. 10 is a configuration diagram showing the bottom plate standby state of the manual sheet feeder viewed from the direction of arrow B1 in FIG. After the registration correction, the paper feed roller shaft 45 is rotated (the first electromagnetic clutch 53 is turned on), and as shown in FIG. , the rotation is stopped (the first electromagnetic clutch 53 is turned off). While the paper feed roller shaft 45 is stopped, the paper feed roller 47 is rotatable by the one-way clutch 46 (see FIG. 4) in conjunction with the conveyance of paper by the rotation of the registration roller pair 21 . Therefore, the recording material S is conveyed by the registration roller pair 21 into the image forming apparatus 1 downstream of the registration roller pair 21 in the conveying direction. Then, the manual sheet feeder 39 enters a standby state as shown in FIG. 6 to prepare for the next sheet feed.

As described above, the manual sheet feeder 39 of the present embodiment moves the bottom plate 41 up and down using the cam member 48a, so that the bottom plate 41 does not need to be moved up and down by the user. Therefore, it is possible to prevent missetting of the recording material due to an erroneous operation by the user. In addition, since the cam member 48a and the paper feeding roller 47 that conveys the recording material S are driven by one driving source (motor 56, first electromagnetic clutch 53, etc.) that also drives the other members, the cost is relatively low. . Furthermore, the manual sheet feeding unit 39 of the present embodiment can also perform registration correction.

2. Description of the Related Art In a paper feeding device, for example, when the end of a recording material is bent or wrinkled, jamming of the recording material (so-called jam) may occur. Jam processing and irregular processing will be described below.

(Jam processing)
11A and 11B are configuration diagrams showing jam processing of the manual sheet feeding unit as viewed from the direction of arrow B1 in FIG. 4. FIG. As shown in FIG. 11, when a jam occurs, the manual paper feeding unit 39 of the present embodiment moves the lever member 49a to the standby position (where the standby position sensor 54 outputs ON) and stops. to descend. That is, even if a jam occurs, the first electromagnetic clutch 53 is not turned off immediately, but after the bottom plate 41 moves to the lowered position, the first electromagnetic clutch 53 is turned off.

Next, the user removes the jammed paper by pulling it out in the pulling direction (opposite to the feeding direction). Since the paper feed roller 47 and the paper feed roller shaft 45 are connected by a one-way clutch 46 (see FIG. 4), the paper feed roller 47 rotates counterclockwise in the drawing (rotating in the direction opposite to the direction in which the paper is conveyed). ), the paper feed roller shaft 45 and the lever member 49a also rotate. On the other hand, the cam member 48a is not fixed to the paper feed roller shaft 45 and is not interlocked with the counterclockwise rotating lever member 49a. The cam member 48a is stopped at the standby position as it is. Therefore, the bottom plate 41 remains lowered.

As described above, since the paper feeding roller 47 also rotates when the recording material S is pulled out, the load for pulling out the recording material S can be reduced, and workability is good.

(Initial operation)
An apparatus including a paper feeder, such as the image forming apparatus 1, stops operating when a jam occurs or an abnormality of the apparatus (such as when a cover is opened) occurs. After that, after the jam or abnormality is eliminated, an initial operation (jam clearing operation) is performed to confirm that there is no abnormality in operation. That is, the presence or absence of jammed paper, the opening and closing of the cover, and the like are checked.

This initial operation differs depending on the standby position of the lever member 49a, that is, the output result of the standby position sensor 54. FIG. Specifically, when the lever member 49a is at the standby position (see FIG. 6) (the standby position sensor 54 is ON), it stands by in that state. On the other hand, when the lever member 49a is not at the standby position (the standby position sensor 54 is OFF), the paper feed roller shaft 45 is rotated and stopped after moving to the standby position.

(Irregular stop state)
The bottom plate 41 may not be in the standby position if power to the device is suddenly turned off, or if the cam member 48a may have stopped at the non-standby position. In this case, after confirming that the recording material S is not on the bottom plate 41 (for example, confirming the presence/absence with a separate paper sensor), the initial operation is started.

FIG. 12 is a configuration diagram showing an irregular stop state (No. 1) of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. As shown in FIG. 12, the lever member 49a is at the non-standby position (standby position sensor 54 is OFF), and the lever member 49a is positioned on the right side of the cam member 48a in the drawing (by the rotation of the paper feed roller shaft 45, the lever member 49a is is positioned to rotate together with the cam member 48a). In this case, as an initial operation, the lever member 49a rotates clockwise in the figure, moves to the standby position and stops (the standby position sensor 54 is ON).

Note that when the recording material S is on the bottom plate 41 (the paper sensor detects the recording material), the initial operation does not start. It is also desirable to display a message prompting removal of the recording material on the operation panel 6 (see FIG. 1) or the like. As a result, it is possible to prevent the recording material from being conveyed during the initial operation.

FIG. 13 is a configuration diagram showing an irregular stop state (No. 2) of the manual sheet feeding unit viewed from the direction of arrow B1 in FIG. As shown in FIG. 13, the lever member 49a is at the non-standby position (standby position sensor 54 is OFF), and the lever member 49a is positioned on the left side of the cam member 48a in the drawing (by the rotation of the paper feed roller shaft 45, the lever member 49a is rotates and the cam member 48a does not rotate). In this case, as an initial operation, the lever member 49a rotates clockwise in the figure, moves to the standby position and stops (the standby position sensor 54 is ON).

However, since the bottom plate 41 is not in the lowered position, the placement of the recording material S is poor. Therefore, the lever member 49a is rotated again to move the cam member 48a to the standby position. That is, the paper feed roller shaft 45 continues to rotate until the standby position sensor 54 outputs ON twice. Since the lever member 49a is positioned on the right side of the cam member 48a in the drawing at the first rotation, the cam member 48a is stopped at the standby position at the second rotation.

Note that when the recording material S is on the bottom plate 41 (the paper sensor detects the recording material), the initial operation does not start. It is also desirable to display a message prompting removal of the recording material on the operation panel 6 (see FIG. 1) or the like. As a result, it is possible to prevent the recording material from being conveyed during the initial operation.

As described above, the manual sheet feeding unit 39 of the present embodiment allows the user to easily perform jam processing. In the irregular stop state, the bottom plate 41 can be placed in the standby state by rotating the paper feed roller shaft 45 twice (the standby position sensor 54 outputs ON twice) when performing the initial operation. .

Supplementary explanation is added about this.

It has been described that a predetermined slack is generated in the registration correction operation. In the present invention, the layout configuration (in particular, the distance between the registration roller pair 21 and the paper feed roller 47) is not limited. This is because the paper feed roller 47 is rotatable until the slack is generated, and the recording material S is continuously pressed by the separation pad 60 even after the pressing by the bottom plate 41 is released.

Further, the linear velocity of the paper feed roller 47 is faster than the linear velocity of the registration roller pair 21 . However, since the paper feed roller shaft 45 stops after the bending of the recording material S is generated, the bending is eliminated. In addition, since the separation pad 60 is provided, as long as the paper feed roller 47 is rotating, the deflection is not eliminated at the ends in the paper feed direction (aligned at the nip portion of the registration roller pair 21).

Advantageous configurations and modifications of the present invention will now be described.

Both the cam members 48a and 48b and the lever members 49a and 49b are preferably provided at left and right positions of the paper feed roller shaft 45, respectively. As a result, the bottom plate 41 descends evenly from side to side, so that the recording material S can be placed more easily.

FIG. 14 is a configuration diagram showing a modified example of the manual paper feed unit viewed from the direction of arrow B1 in FIG. As shown in FIG. 14, it is desirable to provide the bottom plate 41 with stopping means 62 for stopping the cam member 48a. As the stopping means 62 , a rubber stopper can be used, or a U-shaped groove can be provided in the bottom plate 41 . The stopping means 62 can prevent the cam member 48a from coming off the bottom plate 41 due to vibration or the like. The stopping means 62 may be used for one cam member 48a or for both cam members 48a and 48b.

The manual paper feed unit 39 of the present embodiment can be used as an automatic document feeder (ADF) or a paper feed tray (paper feed cassette) in addition to being used as a manual paper feed. Also, the manual sheet feeding unit 39 of the present embodiment can be used in an image reading device. Furthermore, the image forming apparatus 1 including the manual paper feeding unit 39 may be configured as a multi-function device combining two or more of a copier, facsimile machine, printer, printing machine, inkjet recording device, and image reading device. good.

The present invention has been described in detail above using the embodiments. This embodiment is an example, and can be used with various modifications within the scope of the invention.

REFERENCE SIGNS LIST 1 image forming apparatus 2 image forming unit 3 paper feed unit 3a, 3b paper feed cassette 4 in-body paper discharge unit 5 document reading unit 5a contact glass 5b illumination light source 5c first mirror 5d second mirror 5e third mirror 5f imaging lens 5g Image sensor 6 Operation panel 9 Fixing unit 9a Fixing roller 9b Heating roller 9c Fixing belt 9d Pressure roller 11B, 11C, 11M, 11Y Photoreceptor drum 12B, 12C, 12M, 12Y Charging device 13 Optical writing device 14B, 14C, 14M, 14Y developing device 15B, 15C, 15M, 15Y primary transfer roller 16B, 16C, 16M, 16Y cleaning device 17 intermediate transfer belt unit 17a intermediate transfer belt 18 intermediate transfer belt cleaning device 19a, 19b paper feeding device 20a, 20b, 23 , 28, 29 Conveyance roller 21 Registration roller pair 22 Secondary transfer roller 24 Discharge roller 25 Switching claw 26 Reverse conveyance roller 27 Reverse conveyance path 32B, 32C, 32M, 32Y Toner bottle 39 Manual feed unit 40 Manual feed cover 41 Bottom plate 42a Side fence 45 Paper feed roller shaft 46 One-way clutch 47 Paper feed rollers 48a, 48b Cam member 49a, 49b Lever member 50a Protrusion 52 Phase detection filler 53 First electromagnetic clutch 54 Standby position sensor 55 Idler gear 56 Motor 57 Second electromagnetic clutch 58 motor 59, 61 pressure spring 60 separation pad 62 stopping means 65, 67 rotary shaft hole 66 lever 68 cam 70 hole 71 sliding bearing S recording material

Japanese Patent Application Laid-Open No. 2009-107801 Patent No. 5217842 specification Patent No. 5843811 specification

Claims (8)

a drive shaft that rotates the paper feed roller;
a bottom plate on which the recording material is placed;
biasing means for pushing up the bottom plate;
a cam member that contacts the bottom plate and lowers the bottom plate against the biasing force of the biasing means;
a lever member that interlocks with driving of the drive shaft,
By driving the drive shaft, the cam member is separated from the bottom plate in conjunction with the lever member, and the bottom plate is lifted by the biasing means to press the recording material against the paper feed roller. When the recording material hits a pair of registration rollers downstream of the paper feed roller in the conveying direction due to the rotation of the paper feed roller,
A paper feeding device in which the rotation of the paper feeding roller is temporarily stopped, and then the paper feeding roller and the registration roller pair are rotated, and the bottom plate is lowered by the cam member,
comprising a standby position sensor that detects the phase of the lever member;
The standby position sensor is configured to output ON when the lever member is at a predetermined standby position and to output OFF when the lever member is not at the standby position,
2. A paper feeder according to claim 1, wherein when said standby position sensor outputs OFF during an initial operation, said drive shaft continues to rotate until said standby position sensor outputs ON twice . 2. A sheet feeding device according to claim 1, wherein said cam member and said lever member are both provided at left and right positions of said drive shaft. 3. The sheet feeding device according to claim 1, wherein the bottom plate is provided with stopping means for stopping the cam member. 4. The paper feeding device according to claim 1 , wherein the paper feeding device is used for manual paper feeding. 4. The paper feeder according to claim 1 , wherein the paper feeder is used as an automatic document feeder. 4. The paper feeding device according to claim 1 , wherein the paper feeding device is used as a paper feeding tray. An image forming apparatus comprising the sheet feeding device according to claim 1 . 8. The image forming apparatus according to claim 7 , wherein the image forming apparatus is configured as a multi-function machine in which two or more of a copier, facsimile machine, printer, printing machine, inkjet recording apparatus, and image reading apparatus are combined.

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