JP7263769B2 - Sheet feeding device and image forming device - Google Patents

Description

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

2. Description of the Related Art Conventionally, in an image forming apparatus such as a laser printer, there is an image forming apparatus that includes a sheet tray in a cover that can be opened and closed on the side surface of the apparatus main body. This sheet tray uses a pressure plate mechanism that lifts and lowers the sheets by supporting them with a pressure plate in order to increase the load capacity of the sheets and to reduce variations in the feeding pressure applied to the feed rollers due to changes in the load capacity. there is something

When the cover is closed in such an image forming apparatus, the pressure plate and the feeding roller may interfere with each other if miniaturization of the apparatus is prioritized. For this reason, for example, in Japanese Patent Laid-Open No. 2002-100002, a pressure plate that can be moved up and down by rotation of a spring and a cam is used, and when the cover is closed, the pressure plate is lifted and housed at a housing position above the feeding roller.

JP 2016-84233 A

In Patent Document 1, when the cover is closed, the pressure plate is displaced to the accommodation position and the contact portion of the pressure plate and the cam are separated. At this time, since the pressure plate is biased by the spring, the abutting portion of the pressure plate is abruptly separated from the cam, which tends to generate noise. Conversely, when the cover is opened, the abutting portion of the pressure plate is pressed against the cam, which also tends to generate noise. Such a situation is the same not only in an image forming apparatus but also in a configuration having a sheet feeding device such as a document feeding device.

SUMMARY OF THE INVENTION The present invention provides a sheet feeding device that reduces the size of the device by pulling up the pressure plate and housing it in the housing position when the cover is closed, and suppresses the generation of noise when the pressure plate is displaced. With the goal. Another object of the present invention is to provide an image forming apparatus equipped with the sheet feeding device.

A sheet feeding device according to the present invention includes a device main body, a feeding section provided in the device main body for feeding a sheet, a closed position, and an upper end portion higher than the closed position. a cover that swings to an open position far from a side surface of an apparatus main body; a sheet supporting surface that is provided on the cover and can support the sheet when the cover is in the open position; and a supported portion. a supply position where the sheet is pressed against the feeding section by positioning the supported portion at the first position; and a position of the supported portion at a second position below the first position. a pressure plate whose downstream end in the sheet feeding direction swings between a sheet feeding position and a non-feeding position where the sheet is separated from the sheet feeding section; a link member that swings the support portion between an upper position that holds the supported portion at the first position and a lower position that holds the supported portion at the second position; is connected to the main body of the apparatus, and the other end is connected to the pressure plate, and when the cover is in the closed position, the supported portion is separated from the support portion to accommodate the pressure plate above the feeding portion. an arm that is displaced between a first holding position holding the pressure plate in position and a second holding position displaceably holding the pressure plate between the supply position and the non-supply position when the cover is in the open position; Prepare.

According to the above configuration, by moving the pressure plate up and down while supporting the supported portion of the pressure plate from below, the supported portion is separated from the support portion when the cover is closed, and the supported portion moves away from the support portion when the cover is opened. abut.

According to the present invention, when the cover is closed, the supported portion of the pressure plate is separated from the support portion of the link member, and when the cover is opened, the supported portion of the pressure plate only contacts the support portion of the link member. It is difficult to generate a sound between the part and the supporting part. In addition, when the cover is closed, the supported portion of the pressure plate is separated from the supporting portion of the link member so that the pressure plate is housed above the feeding portion, so that the size of the apparatus can be reduced.

1 is a central sectional view of an image forming apparatus according to a first embodiment; FIG. FIG. 3 is a perspective view showing the essential part of the MP feeding mechanism of the first embodiment; Figure 3 is a side sectional view of Figure 2; FIG. 4 is a diagram showing a state in which the pressure plate is at the supply position in FIG. 3; 4 is a diagram showing a state in which the MP tray in FIG. 3 has swung toward a closed position; FIG. 6 is a diagram showing a state in which the MP tray in FIG. 5 has swung toward the closed position; FIG. FIG. 7 is a diagram showing a state in which the MP tray is in the closed position in FIG. 6; 5 is a diagram showing a state in which the MP tray in FIG. 4 has swung toward a closed position; FIG. FIG. 9 is a diagram showing a state in which the MP tray has swung toward the closed position in FIG. 8; FIG. 10 is a diagram showing a state in which the MP tray is in the closed position in FIG. 9; FIG. 11 is a side cross-sectional view showing the main part of the MP feeding mechanism of the second embodiment; FIG. 12 is a diagram showing a state in which the pressure plate is at the supply position in FIG. 11; FIG. 12 is a diagram showing a state in which rearward displacement of the pressure plate is restricted in FIG. 11 ;

[First embodiment]
In the following description, the state in which the image forming apparatus 1 is installed for use as shown in FIG. The left and right directions are defined when the image forming apparatus 1 is viewed from the front side, and the discharge tray 82 side of the image forming apparatus 1 is defined as the top, and the opposite side is defined as the bottom.

<Overall Configuration of Image Forming Apparatus>
FIG. 1 is a central sectional view of an image forming apparatus 1 of the first embodiment. The image forming apparatus 1 includes an apparatus main body 2 , a supply unit 3 , a motor 4 , an image forming unit 5 as an example of an image forming section, and a discharge unit 8 .

The supply unit 3 is arranged in the lower and front portions of the image forming apparatus 1 and conveys the sheet S held by the supply unit 3 to the image forming unit 5 . The image forming unit 5 is arranged downstream of the supply unit 3 in the conveying direction of the sheet S, and forms an image on the sheet S conveyed from the supply unit 3 . The discharge unit 8 is arranged downstream of the image forming unit 5 in the conveying direction of the sheet S, and discharges the sheet S on which an image has been formed by the image forming unit 5 to the outside of the image forming apparatus 1 .

The supply unit 3 includes a sheet cassette 10, a feeding mechanism 20, a conveying roller 24, and a registration roller 25 in the lower portion of the image forming apparatus 1, and a front cover 90 and a sheet feeding unit in the front portion of the image forming apparatus 1. and an MP feeding mechanism 26 as an example of a member constituting the feeding device.

The sheet cassette 10 is detachably attached to a sheet cassette attachment portion 2B formed in the lower portion of the apparatus main body 2. As shown in FIG. The sheet cassette 10 is mounted on the sheet cassette mounting portion 2B by inserting it from the front to the rear into the sheet cassette mounting portion 2B, and is positioned at the mounting position. Further, the sheet cassette 10 is moved from the mounting position to the drawing position by pulling out the sheet cassette mounting portion 2B from the rear toward the front.

The sheet cassette 10 includes a cassette body 11 capable of supporting a plurality of sheets S, a pressure plate 12 arranged in the cassette body 11 on which the sheets S are stacked and capable of vertically displacing the sheets S, and the pressure plate 12 being raised. and a pressure plate lifting member 13 for

The pressure plate 12 is rotatably supported by a rotation fulcrum 12A, and can be displaced in the vertical direction. The pressure plate lifting member 13 is driven by the motor 4 to lift the tip. As the pressure plate lifting member 13 rises, the pressure plate 12 is lifted, and the sheet S stacked on the pressure plate 12 is raised to a feedable position as shown in FIG.

The feeding mechanism 20 is a mechanism that separates and takes out the sheets S stacked on the sheet cassette 10 one by one and conveys them toward the conveying rollers 24 . The feeding mechanism 20 includes a pickup roller 21 , a separation roller 22 and a separation pad 23 .

The pickup roller 21 is a roller for picking up the sheet S lifted to the feedable position by the pressure plate 12 , and is arranged above the pressure plate 12 . The separation roller 22 is arranged downstream of the pickup roller 21 in the conveying direction of the sheet S, and the separation pad 23 is arranged to face the separation roller 22 and is biased toward the separation roller 22 .

The sheet S picked up by the pickup roller 21 is delivered to the separation roller 22 side, separated sheet by sheet between the separation roller 22 and the separation pad 23 , and conveyed toward the conveying roller 24 .

The conveying roller 24 is a roller that applies a conveying force to the sheet S, and is arranged downstream of the feeding mechanism 20 in the sheet S conveying direction. The sheet S conveyed from the feeding mechanism 20 to the conveying rollers 24 is conveyed toward the registration rollers 25 .

The registration rollers 25 are arranged downstream of the transport rollers 24 in the sheet S transport direction. The registration rollers 25 regulate the movement of the leading edge of the conveyed sheet S, temporarily stop it, and then convey it toward the transfer position at a predetermined timing.

A first opening 2</b>A is formed in the front surface of the apparatus main body 2 for clearing a jam of the sheet S or for exchanging the image forming unit 5 . A front cover 90 that can be opened and closed with its lower end as a fulcrum is attached to the first opening 2A. A second opening 90A for feeding sheets S is formed in the front surface of the front cover 90 . An MP tray 27 as an example of a cover that can be opened and closed with its lower end as a fulcrum is attached to the second opening 90A. The MP tray 27 has a closed position covering the second opening 90A and an open position (position shown in FIG. 1) in which the upper end is farther from the front surface of the apparatus body 2 than in the closed position and opens the second opening 90A. It is possible to swing between.

The MP feeding mechanism 26 is a mechanism that separates and takes out the sheets S on the MP tray 27 one by one and conveys them toward the registration rollers 25 . The MP feeding mechanism 26 includes an MP tray 27 , a pickup roller 28 as an example of a feeding roller, a separation roller 29 and a retard roller 30 . The pickup roller 28 , the separation roller 29 and the retard roller 30 constitute a feeding section 280 .

A pickup roller 28 is a roller for picking up the sheet S on the MP tray 27 . The separation roller 29 is arranged downstream of the pickup roller 28 in the sheet conveying direction, and the retard roller 30 is arranged to face the separation roller 29 and is biased toward the separation roller 29 .

The sheet S picked up by the pickup roller 28 is delivered toward the separation roller 29 , separated sheet by sheet between the separation roller 29 and the retard roller 30 , and conveyed toward the registration roller 25 . Instead of the retard roller 30, a separation pad may be arranged to face the separation roller 29. FIG. In this case, the sheets S picked up by the pickup roller 28 are separated one by one between the separation roller 29 and the separation pad, and conveyed toward the registration rollers 25 .

The image forming unit 5 includes a process cartridge 50 that transfers an image onto the surface of the sheet S conveyed from the supply unit 3 , an exposure unit 60 that exposes the surface of the photosensitive drum 54 of the process cartridge 50 , and the process cartridge 50 . A fixing unit 70 for fixing the image transferred to the sheet S is provided.

The process cartridge 50 is arranged above the sheet cassette mounting portion 2B in the apparatus main body 2 . The process cartridge 50 includes a developer storage chamber 51 , a supply roller 52 , a development roller 53 , a photosensitive drum 54 and a transfer roller 55 .

The developer containing chamber 51 contains toner as a developer. The toner stored in the developer storage chamber 51 is sent to the supply roller 52 while being stirred by a stirring member (not shown). The supply roller 52 further supplies the toner sent from the developer storage chamber 51 to the development roller 53 .

The developing roller 53 is arranged in close contact with the supply roller 52 and carries the toner supplied from the supply roller 52 . A developing bias is applied to the developing roller 53 by bias applying means (not shown).

The photosensitive drum 54 is arranged adjacent to the developing roller 53 . The surface of the photosensitive drum 54 is uniformly charged by a charger (not shown) and then exposed by the exposure unit 60 . The exposed portion of the photoreceptor drum 54 has a lower potential than other portions, and an electrostatic latent image based on the image data is formed on the photoreceptor drum 54 . Then, charged toner is supplied from the developing roller 53 to the surface of the photosensitive drum 54 on which the electrostatic latent image is formed, whereby the electrostatic latent image is developed into a developer image.

The transfer roller 55 is arranged opposite to the photosensitive drum 54, and a transfer bias is applied by a bias applying means (not shown). In a state in which a transfer bias is applied to the surface of the transfer roller 55, the sheet S is nipped and conveyed between the photosensitive drum 54 on which the developer image is formed and the transfer roller 55 (transfer position). A developer image formed on the surface of the photosensitive drum 54 is transferred to the surface of the sheet S. As shown in FIG.

The exposure unit 60 includes a laser diode, a polygon mirror, a lens, and a reflecting mirror, and irradiates the photosensitive drum 54 with laser light based on image data input to the image forming apparatus 1. , the surface of the photosensitive drum 54 is exposed.

The fixing unit 70 has a heating roller 71 and a pressing roller 72 . The heating roller 71 is rotationally driven by the driving force from the motor 4, and is heated by supplying power from a power source (not shown). The pressing roller 72 is arranged to face the heating roller 71 and is in close contact with the heating roller 71 and is driven to rotate. When the sheet S to which the developer image has been transferred is conveyed to the fixing unit 70, the sheet S is conveyed while being nipped between the heating roller 71 and the pressing roller 72, and the developer image is fixed on the sheet S.

The discharge unit 8 includes a discharge roller 81 , a discharge tray 82 and a discharge port 83 . The discharge rollers 81 are a pair of rollers, and discharge the sheet S conveyed from the fixing unit 70 toward the outside of the apparatus main body 2 . The discharge tray 82 is formed on the upper surface of the apparatus main body 2 , and the sheets S discharged to the outside of the apparatus main body 2 from the discharge port 83 by the discharge roller 81 are deposited on the discharge tray 82 .

<Configuration of MP Feeding Mechanism>
2 is a perspective view showing the essential parts of the MP feeding mechanism 26 of the first embodiment, FIG. 3 is a side cross-sectional view of FIG. 2, and FIG. 4 is a diagram showing a state where the pressure plate 31 is at the supply position in FIG. .

In addition to the above-described MP tray 27, pickup roller 28, separation roller 29, and retard roller 30, the MP feeding mechanism 26 includes, as shown in FIG. A pair of left and right arms 33 are provided.

The MP tray 27 has a flat plate portion 27A, a left wall portion 27B extending along the left end of the flat plate portion 27A, and a right wall portion 27C extending along the right end of the flat plate portion 27A. The left wall portion 27B and the right wall portion 27C are provided with ribs 27D (see FIG. 3) that are guided by the rails 31F of the pressure plate 31, and long hole portions 27E that movably support the rotary shaft portion 31E of the pressure plate 31. is formed.

The pressure plate 31 is a plate-like member provided on the MP tray 27 . The pressure plate 31 includes a sheet support surface 31A capable of supporting a plurality of sheets S when the MP tray 27 is in the open position, a left wall portion 31B extending along the left end of the sheet support surface 31A, and a sheet support surface 31A. and a right wall portion 31C extending along the right end.

A columnar supported portion 31D supported by the support portion 32A of the link member 32 is formed at the rear end portions of the left wall portion 31B and the right wall portion 31C. At the front ends of the left wall portion 31B and the right wall portion 31C, a rotary shaft portion 31E supported by the hole portion 33B of the arm 33 and the elongated hole portion 27E of the MP tray 27 is formed. Two rails 31F for guiding the ribs 27D of the MP tray 27 are formed in the middle of the left wall portion 31B and the right wall portion 31C. Contrary to this embodiment, the MP tray 27 may be provided with the rails 31F and the pressure plate 31 may be provided with the ribs 27D.

4 and the non-supply position shown in FIG. 3 due to the vertical movement of the link member 32. is swingable. Specifically, the supply position is a position where the supported portion 31D is lifted by the link member 32 and positioned at the first position (the position shown in FIG. 4) so that the sheet S is pressed against the pickup roller . On the other hand, in the non-supply position, the supported portion 31D is positioned at the second position (position shown in FIG. 3) below the first position by lowering the link member 32, thereby separating the sheet S from the pickup roller 28. position.

In such a pressure plate 31, the supported portion 31D is provided outside the sheet supporting surface 31A in the lateral direction, which is the width direction orthogonal to the sheet feeding direction, as shown in FIG. As a result, the pressure plate 31 is moved up and down outside the feeding section 280 provided in the area through which the sheet S passes, so that the supported section 31D can be arranged so as not to interfere with the feeding section 280 .

Further, as shown in FIG. 7, when the MP tray 27 is at the closed position, the pressure plate 31 is held at the accommodation position. In this embodiment, the pressure plate 31 in the retracted position is positioned above the pickup roller 28 and the separation roller 29 . In this way, since the pressure plate 31 is located at the back of the apparatus main body 2 at the housed position, a space can be provided between the pressure plate 31 and the MP tray 27, and an extension tray or the like can be arranged in that space. Note that the pressure plate 31 at the accommodation position may be positioned only above the pickup roller 28 . In other words, the pressure plate 31 at the accommodation position should be positioned at least above the feeding section 280 .

The link member 32 is a rod-shaped member provided on the device main body 2 . A support portion 32A capable of supporting the supported portion 31D of the pressure plate 31 from below is formed at the front end portion of the link member 32. As shown in FIG. The support portion 32A is a flat plate-shaped projection, and the upper surface of the support portion 32A supports the supported portion 31D by coming into contact with the supported portion 31D from below. A rotation shaft portion 32</b>B that is rotated by the driving force from the motor 4 is formed at the rear end portion of the link member 32 .

As the link member 32 is driven by the motor 4, the supporting portion 32A swings around the rotating shaft portion 32B between the upper position shown in FIG. 4 and the lower position shown in FIG. Specifically, the upper position is a position where the support portion 32A lifts the supported portion 31D and holds it at the first position, thereby holding the pressure plate 31 at the supply position. On the other hand, the lower position is a position where the support portion 32A is positioned below the upper position and the pressure plate 31 is held at the non-supply position by holding the supported portion 31D at the second position.

Such a link member 32 is provided at a different position with respect to the retard roller 30 in the rotation axis direction of the retard roller 30, and when viewed from the rotation axis direction, the retard roller 30 and the link member 32 swing. At least a portion of the range of motion overlaps. In this embodiment, the link member 32 is provided outside the retard roller 30 in the left-right direction, and when viewed in the left-right direction as shown in FIG. It overlaps with the retard roller 30 . In this manner, the link member 32 can be arranged at a position that does not interfere with the retard roller 30 and does not increase the size of the apparatus main body 2 .

Note that the support portion 32A of the link member 32 may be configured to support the surface of the pressure plate 31 opposite to the sheet support surface 31A, as long as the arrangement space can be secured. In this case, the surface of the pressure plate 31 opposite to the sheet supporting surface 31A is an example of the supported portion.

As shown in FIG. 2, the arm 33 is a rod-like member whose rear end is connected to the apparatus main body 2 and whose front end is connected to the rotation shaft portion 31E of the pressure plate 31 . At the rear end of the arm 33, a columnar shaft 33A is formed which is movably supported in the elongated hole 2C of the device main body 2. As shown in FIG. A hole portion 33B is formed in the front end portion of the arm 33 to rotatably support the rotation shaft portion 31E of the pressure plate 31 .

The arm 33 is displaced between the first holding position shown in FIG. 7 and the second holding position shown in FIGS. 3 and 4 by opening and closing the MP tray 27 . Specifically, in the first holding position, the MP tray 27 is in the closed position, the shaft portion 33A is positioned at the lower end of the long hole portion 2C, and the supported portion 31D is separated from the support portion 32A to feed the pressure plate 31. This is the position where it is held in the stowed position above the portion 280 . On the other hand, the second holding position is a position where the MP tray 27 is at the open position, the shaft portion 33A is positioned at the upper end of the elongated hole portion 2C, and the pressure plate 31 is held movably between the supply position and the non-supply position.

<Operation of MP feeding mechanism>
The operation of the MP feeding mechanism 26 when opening and closing the MP tray 27 will be described in two forms with reference to FIGS. 3 to 10. FIG. The first is a form in which the MP tray 27 is swung to the closed position from a state in which the MP tray 27 is at the open position and the support portion 32A is at the lower position, and then the MP tray 27 is swung to the open position from that state. be. The second is a form in which the MP tray 27 is swung to the closed position from a state in which the MP tray 27 is at the open position and the support portion 32A is at the upper position, and then the MP tray 27 is swung to the open position from that state. be.

First, the first form will be explained. When the image forming apparatus 1 is not driven, such as after printing, the MP tray 27 is at the open position, the support portion 32A is at the lower position, and the pressure plate 31 is at the non-supply position, as shown in FIG. is in a certain state. When the user swings the MP tray 27 toward the closed position from this state, the shaft portion 33A of the arm 33 moves from the upper end to the lower end in the elongated hole portion 2C of the apparatus main body 2, resulting in the state shown in FIG. .

When the MP tray 27 is further swung toward the closed position from the state shown in FIG. 5, as shown in FIG. It is pushed up and moves along the long hole portion 27E of the MP tray 27 . At this time, the rails 31F of the pressure plate 31 move while guiding the ribs 27D of the MP tray 27. As shown in FIG.

As a result, the supported portion 31D of the pressure plate 31 moves upward from the second position, separates from the supporting portion 32A, and passes through the first position indicated by the chain double-dashed line. Since the supported portion 31D is separated upward from the supporting portion 32A with which it is in contact, noise is less likely to occur between the supported portion 31D and the supporting portion 32A. Further, the shape of the rail 31F is designed so that the supported portion 31D passes through the first position.

When the MP tray 27 is further swung toward the closed position from the state shown in FIG. 6, the rotation shaft portion 31E of the pressure plate 31 is further pushed up by the arm 33, and the MP tray 27 is moved to the closed position as shown in FIG. , the arm 33 reaches the first holding position, and the pressure plate 31 reaches the housing position.

Next, when the MP tray 27 is opened from the state shown in FIG. 7, the operations described above are reversed. That is, when the user swings the MP tray 27 toward the open position from the state shown in FIG. 7, the rotation shaft portion 31E of the pressure plate 31 tilts forward about the shaft portion 33A as shown in FIG. It is pushed down by the arm 33 to move along the elongated hole 27E of the MP tray 27. As shown in FIG. At this time, the rails 31F of the pressure plate 31 move while guiding the ribs 27D of the MP tray 27. As shown in FIG.

When the MP tray 27 is further swung toward the open position from the state shown in FIG. 6, the supported portion 31D of the pressure plate 31 passes through the first position indicated by the two-dot chain line, and moves to the second position as shown in FIG. , and comes into contact with the support portion 32A. Since the supported portion 31D only contacts the support portion 32A at the speed at which the MP tray 27 swings, noise is less likely to occur between the supported portion 31D and the support portion 32A.

When the MP tray 27 is further swung toward the open position from the state shown in FIG. 5, the shaft portion 33A of the arm 33 moves from the lower end to the upper end in the elongated hole portion 2C of the apparatus main body 2, and as shown in FIG. , the MP tray 27 reaches the open position.

Next, the second form will be explained. When the driving of the image forming apparatus 1 is stopped due to a power failure or the like during printing, as shown in FIG. It is in a state of When the user swings the MP tray 27 toward the closed position from this state, the shaft portion 33A of the arm 33 moves from the upper end to the lower end in the long hole portion 2C of the apparatus main body 2, resulting in the state shown in FIG. .

When the MP tray 27 is further swung toward the closed position from the state shown in FIG. 8, as shown in FIG. It is pushed up and moves along the long hole portion 27E of the MP tray 27 . At this time, the rails 31F of the pressure plate 31 move while guiding the ribs 27D of the MP tray 27. As shown in FIG. As a result, the supported portion 31D of the pressure plate 31 moves forward and upward from the first position and separates from the support portion 32A. Since the supported portion 31D is spaced obliquely upward from the contacting support portion 32A, noise is less likely to occur between the supported portion 31D and the support portion 32A.

When the MP tray 27 is further swung toward the closed position from the state shown in FIG. 9, the rotation shaft portion 31E of the pressure plate 31 is further pushed up by the arm 33, and the MP tray 27 is moved to the closed position as shown in FIG. , the arm 33 reaches the first holding position, and the pressure plate 31 reaches the accommodation position.

Next, when the MP tray 27 is opened from the state shown in FIG. 10, the operations described above are reversed. That is, when the user swings the MP tray 27 toward the open position from the state shown in FIG. 10, as shown in FIG. It is pushed down by the arm 33 to move along the elongated hole 27E of the MP tray 27. As shown in FIG. At this time, the rails 31F of the pressure plate 31 move while guiding the ribs 27D of the MP tray 27. As shown in FIG.

When the MP tray 27 is further swung toward the open position from the state shown in FIG. 9, the supported portion 31D of the pressure plate 31 reaches the first position and contacts the support portion 32A as shown in FIG. After the supported portion 31D reaches the first position, the rib 27D is separated from the rail 31F. Since the supported portion 31D only contacts the support portion 32A at the speed at which the MP tray 27 swings, noise is less likely to occur between the supported portion 31D and the support portion 32A.

When the MP tray 27 is further swung toward the open position from the state shown in FIG. 8, the shaft portion 33A of the arm 33 moves from the lower end to the upper end in the elongated hole portion 2C of the apparatus main body 2, and as shown in FIG. , the MP tray 27 reaches the open position. After that, when the power supply to the image forming apparatus 1 is restored, the link member 32 is driven by the motor 4 to swing to the lower position, and as shown in FIG. It can be used normally.

As described above, according to the image forming apparatus 1 of the first embodiment, the supported portion 31D always passes through the first position when the MP tray 27 is opened. The portion 31D is transferred to the support portion 32A. Therefore, even if the MP tray 27 is closed with the link member 32 stopped at the upper position due to a power failure or the like, it can be used normally upon recovery.

Further, according to the image forming apparatus 1 of the first embodiment, the supported portion 31D of the pressure plate 31 is moved up and down while the supported portion 31D of the pressure plate 31 is supported from below. When the MP tray 27 is separated from 32A and the MP tray 27 is opened, only the supported portion 31D abuts against the support portion 32A, so noise is less likely to occur between the supported portion 31D and the support portion 32A. In addition, since the pressure plate 31 is accommodated above the feeding section 280 by separating the supported section 31D from the supporting section 32A when the MP tray 27 is closed, the size of the apparatus main body 2 can be reduced.

[Second embodiment]
Next, an image forming apparatus according to the second embodiment will be described. The image forming apparatus of the second embodiment differs from the image forming apparatus 1 of the first embodiment in the shape of members in the MP feeding mechanism 260, and the rest is the same as the image forming apparatus 1 of the first embodiment. In the following description, the MP feeding mechanism 260 will be described, and the same members as those of the image forming apparatus 1 of the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

<Configuration of MP Feeding Mechanism>
FIG. 11 is a side cross-sectional view showing the essential parts of the MP feeding mechanism 260 of the second embodiment. FIG. 12 is a diagram showing a state where the pressure plate 310 in FIG. 11 is at the supply position. FIG. 13 is a diagram showing a state in which rearward displacement of the pressure plate 310 in FIG. 11 is restricted. In the MP feeding mechanism 260 of the second embodiment, the MP tray 27 is replaced with the MP tray 270, the pressure plate 31 is replaced with the pressure plate 310, and the link member 32 is replaced with the link member 320 in the MP feeding mechanism 26 of the first embodiment. Configuration.

The MP tray 270 has a closed position covering the second opening 90A and an open position (position shown in FIG. 11) in which the upper end is farther from the front surface of the apparatus main body 2 than in the closed position and opens the second opening 90A. It is possible to swing between. The MP tray 270 has a flat plate portion 270A, a left wall portion (not shown) extending along the left end of the flat plate portion 270A, and a right wall portion 270C extending along the right end of the flat plate portion 27A. The left wall portion and the right wall portion 270C are formed with long hole portions 270E that movably support the rotation shaft portion 310E of the pressure plate 310, respectively.

The pressure plate 310 is a plate-like member provided on the MP tray 270 . The pressure plate 310 includes a sheet support surface (not shown) capable of supporting a plurality of sheets S when the MP tray 270 is in the open position, a left wall portion 310B extending along the left end of the sheet support surface, and a sheet support surface. and a right wall portion (not shown) extending along the right edge of the face.

A columnar supported portion 310D supported by the support portion 320A of the link member 320 is formed at the rear end portions of the left wall portion 310B and the right wall portion. At the front ends of the left wall portion 310B and the right wall portion, a rotary shaft portion 310E supported by the hole portion 33B of the arm 33 and the elongated hole portion 270E of the MP tray 270 is formed.

12 and the non-supply position shown in FIG. 11 by the vertical movement of the link member 320, the pressure plate 310 is moved to the downstream end side in the sheet feeding direction about the rotating shaft portion 310E. is swingable.

In such a pressure plate 310, the supported portion 310D is provided outside the sheet supporting surface in the left-right direction, as in the first embodiment. As a result, the pressure plate 310 is raised and lowered outside the feeding portion 280 provided in the area through which the sheet S passes, so that the supported portion 310D can be arranged so as not to interfere with the feeding portion 280. FIG.

The link member 320 is a substantially L-shaped member provided in the apparatus main body 2 when viewed from the side. A front end portion of the link member 320 is formed with a support portion 320A capable of supporting the supported portion 310D of the pressure plate 310 from below. The support portion 320A has a flat plate shape, and the upper surface of the support portion 320A supports the supported portion 310D by coming into contact with the supported portion 310D from below.

At the rear end of the link member 320, a rotating shaft portion 320B that is rotated by the driving force from the motor 4 is formed. Driven by the motor 4, the link member 320 swings about the rotary shaft portion 320B between the upper position shown in FIG. 12 and the lower position shown in FIG.

The link member 320 is formed with a protruding portion 320C that protrudes downward from the front end portion of the support portion 320A and has an arcuate shape in a side view. As shown in FIG. 13, when the link member 320 is in the upper position, the protruding portion 320C contacts the supported portion 310D of the pressure plate 310 that is displaced as the MP tray 270 swings from the closed position to the open position. contact, and restricts the pressure plate 310 from being displaced in the rearward direction.

In this state, the rear end side of the pressure plate 310 is supported by the MP tray 270 by the contact portion 310G near the supported portion 310D of the pressure plate 310 coming into contact with the MP tray 270 . Then, when the link member 320 is displaced toward the lower position from the state in which the projecting portion 320C restricts the supported portion 310D, the projecting portion 320C guides the supported portion 310D to the supporting portion 320A.

The length and shape of the protruding portion 320C are particularly limited as long as they have a length that allows the supported portion 310D to be restricted and have a shape that can guide the supported portion 310D to the supporting portion 320A. Instead, it may have a shape that extends linearly in a side view, for example.

Similar to the first embodiment, such a link member 320 is provided at a different position with respect to the retard roller 30 in the direction of the rotation axis of the retard roller 30. When viewed from the direction of the rotation axis, the retard At least part of the swing range of the roller 30 and the link member 320 overlap.

In this embodiment, the link member 320 is provided outside the retard roller 30 in the left-right direction, and when viewed in the left-right direction as shown in FIG. It overlaps with the retard roller 30 . In this manner, the link member 320 can be arranged at a position that does not interfere with the retard roller 30 and does not increase the size of the apparatus main body 2 .

Note that if an arrangement space can be secured, the support portion 320A of the link member 320 can support the surface of the pressure plate 310 opposite to the sheet support surface, and the projecting portion 320C can abut the rear end of the pressure plate 310. may In this case, the rear end portion of the pressure plate 310 including the surface opposite to the sheet supporting surface of the pressure plate 310 and the rear end is an example of the supported portion.

The link member 320 may be provided with an auxiliary projection that faces the upper end of the supported portion 310D while the supporting portion 320A supports the supported portion 310D. According to this configuration, when the link member 320 is displaced from the upper position to the lower position, the auxiliary projection pushes down the supported portion 310D, thereby reliably lowering the pressure plate 310 to the non-supply position.

<Operation of MP feeding mechanism>
The operation of the MP feeding mechanism 260 when opening and closing the MP tray 270 will be described with reference to FIGS. 11 to 13. FIG.

First, the case of closing the MP tray 270 will be described. When the user swings the MP tray 270 toward the closed position from the state shown in FIG. 11 or 12, the rotation shaft portion 310E of the pressure plate 310 rotates about the shaft portion 33A as in the first embodiment. It is pushed up by the moving arm 33 and moves along the elongated hole 270E of the MP tray 270 . As a result, the supported portion 310</b>D of the pressure plate 310 is separated from the support portion 320</b>A, and the contact portion 310</b>G of the pressure plate 310 moves while contacting the MP tray 270 .

In this way, since the supported portion 310D is only separated from the supporting portion 320A that is in contact with the supported portion 310D, noise is less likely to occur between the supported portion 310D and the supporting portion 320A. Thereafter, as in the first embodiment, the rotating shaft portion 310E of the pressure plate 310 is further pushed up by the arm 33, the MP tray 270 reaches the closed position, the arm 33 reaches the first holding position, and the pressure plate 310 reaches the stowed position.

Next, the case of opening the MP tray 270 will be described. When the MP tray 270 in the closed position is swung toward the open position by the user, the rotating shaft portion 310E of the pressure plate 310 tilts forward about the shaft portion 33A due to the operation opposite to that described above. , and moves along the elongated hole 270E of the MP tray 270. As shown in FIG. At this time, the contact portion 310</b>G of the pressure plate 310 moves while contacting the MP tray 270 .

Here, when the link member 320 is in the lower position, as shown in FIG. 11, the supported portion 310D moves to the second position and contacts the supporting portion 320A. Since the supported portion 310D only abuts on the supporting portion 320A at the speed at which the MP tray 270 swings, noise is less likely to occur between the supported portion 310D and the supporting portion 320A.

On the other hand, when the link member 320 is in the upper position due to a power failure or the like, as shown in FIG. 13, the supported portion 310D comes into contact with the projecting portion 320C, and the pressure plate 310 is restricted from moving backward. After that, when the power supply is restored, the link member 320 is driven by the motor 4 to swing toward the lower position, and the projecting portion 320C guides the supported portion 310D to the supporting portion 320A. Then, as shown in FIG. 11, the pressure plate 310 is positioned at the non-supply position and is ready for normal use.

As described above, according to the image forming apparatus of the second embodiment, even if the link member 320 is stopped at the upper position when the MP tray 270 is opened, the supported portion 310D abuts the protruding portion 320C and The portion 310D does not enter under the support portion 320A. When the power is restored, the link member 320 is displaced to the lower position, so that the supported portion 310D is guided onto the support portion 320A along the protruding portion 320C, and can be used normally.

Further, according to the image forming apparatus of the second embodiment, the pressure plate 310 is raised and lowered while the supported portion 310D of the pressure plate 310 is supported from below. Accordingly, when the MP tray 270 is closed, the supported portion 310D is separated from the supporting portion 320A, and when the MP tray 270 is opened, the supported portion 310D only contacts the supporting portion 320A. Sound is less likely to occur between 320A. In addition, since the pressure plate 310 is accommodated above the feeding section 280 by separating the supported section 310D from the supporting section 320A when the MP tray 270 is closed, the apparatus main body 2 can be made smaller.

[Effects of Embodiment]
The sheet feeding device mounted on the image forming apparatus 1 of the first embodiment includes an apparatus main body 2, a feeding section 280 provided in the apparatus main body 2 for feeding the sheet S, and a and an MP tray 27 that swings between a closed position and an open position where the upper end is farther from the side surface of the apparatus main body 2 than the closed position. The sheet feeding device is provided on the MP tray 27 and has a sheet supporting surface 31A capable of supporting the sheet S when the MP tray 27 is in the open position, and a supported portion 31D. 31D is located at the first position, the supply position where the sheet S is pressed against the feeding portion 280; A pressure plate 31 is provided whose downstream end side in the sheet feeding direction swings between a non-supply position where the sheet S is separated. Further, the sheet feeding apparatus has a support portion 32A provided in the apparatus main body 2 and capable of supporting the supported portion 31D from below, and has an upper position for holding the supported portion 31D at a first position, and an upper position for holding the supported portion 31D at a first position. A link member 32 in which a support portion 32A swings between a lower position that holds a second position and a lower position. The sheet feeding device has one end connected to the device main body 2 and the other end connected to the pressure plate 31. When the MP tray 27 is in the closed position, the supported portion 31D is separated from the support portion 32A so that the pressure plate 31 is held at the accommodation position above the feeding unit 280, and the second holding position holds the pressure plate 31 displaceably between the supply position and the non-supply position when the MP tray 27 is in the open position. It has an arm 33 that displaces at .

According to this configuration, the supported portion 31D of the pressure plate 31 is moved up and down while the supported portion 31D of the pressure plate 31 is supported from below. When the tray 27 is opened, the supported portion 31D only abuts the supporting portion 32A, so that noise is less likely to occur between the supported portion 31D and the supporting portion 32A. Further, when the MP tray 27 is closed, the supported portion 31D is separated from the supporting portion 32A so that the pressure plate 31 is accommodated above the feeding portion 280. Therefore, the size of the apparatus can be reduced.

The above sheet feeding device also includes rails 31</b>F provided on the pressure plate 31 and ribs 27</b>D provided on the MP tray 27 . The rail 31F guides the rib 27D so that the supported portion 31D of the pressure plate 31, which is displaced as the MP tray 27 swings from the closed position to the open position, reaches the first position when the MP tray 27 is in the open position. do.

According to this configuration, since the supported portion 31D always passes through the first position when the MP tray 27 is opened, the supported portion 31D is transferred to the support portion 32A regardless of the position of the link member 32. Therefore, even if the MP tray 27 is closed with the link member 32 stopped at the upper position due to a power failure or the like, it can be used normally upon recovery.

According to the sheet feeding apparatus mounted in the image forming apparatus of the second embodiment, the link member 320 has the protruding portion 320C that protrudes downward from the upstream end of the supporting portion 320A in the sheet feeding direction. When the link member 320 is in the upper position, the protruding portion 320C abuts on the supported portion 310D of the pressure plate 310 that is displaced as the MP tray 270 swings from the closed position to the open position. Regulates displacement to the downstream side in the feeding direction.

According to this configuration, even if the link member 320 is stopped at the upper position when the MP tray 270 is opened, the supported portion 310D does not enter under the support portion 320A. When the power is restored, the link member 320 is displaced to the lower position, so that the supported portion 310D is guided onto the support portion 32A along the protruding portion 320C, and can be used normally.

Further, according to the sheet feeding apparatus of the first embodiment or the second embodiment, the feeding section 280 includes the pickup roller 28 and the separation roller 29 arranged downstream of the pickup roller 28 in the sheet feeding direction. have The pressure plate 31 or 310 at the accommodation position is positioned above the pickup roller 28 and the separation roller 29 .

According to this configuration, since the pressure plate 31 or 310 is located at the back of the apparatus main body 2 at the housed position, a space can be provided between the pressure plate 31 or 310 and the MP tray 27, and an extension tray or the like can be arranged in the space. can do.

Further, according to the sheet feeding apparatus of the first embodiment or the second embodiment, the retard roller 30 facing the separation roller 29 is provided. The link member 32 or 320 is provided at a different position with respect to the retard roller 30 in the rotation axis direction of the retard roller 30 . When viewed from the rotation axis direction, at least part of the swing range of the retard roller 30 and the link member 32 or 320 overlaps.

According to this configuration, even in a configuration in which the retard roller 30 is provided, the link member 32 or 320 can be arranged at a position that does not interfere with the retard roller 30 and does not increase the size of the device.

Further, according to the sheet feeding apparatus of the first embodiment or the second embodiment, in the pressure plate 31 or 310, the supported portion 31D or 310D is positioned at the sheet supporting surface 31A in the width direction orthogonal to the sheet feeding direction. It is provided outside with respect to

According to this configuration, since the pressure plate 31 is raised and lowered outside the feeding portion 280 provided in the area through which the sheet S passes, the supported portion 31D can be arranged so as not to interfere with the feeding portion 280. .

1 image forming apparatus 2 apparatus main body 5 image forming unit (image forming section)
27, 270 MP tray (cover)
27D rib 28 pickup roller (feeding roller)
29 separation roller 30 retard roller 31, 310 pressure plate 31A sheet support surface 31D, 310D supported portion 31F rail 32, 320 link member 32A, 320A support portion 33 arm 280 feeding portion 320C projecting portion S sheet

Claims (6)

a device body;
a feeding unit provided in the apparatus main body for feeding sheets;
a cover that is provided on the device main body and swings between a closed position and an open position in which an upper end is farther from the side surface of the device main body than the closed position;
The cover has a seat support surface that can support the seat when the cover is in the open position, and a supported portion, and the supported portion is positioned at the first position, whereby the Between a supply position where the sheet is pressed against the feeding portion and a non-supply position where the sheet is separated from the feeding portion by positioning the supported portion at a second position below the first position. a pressure plate whose downstream end in the sheet feeding direction swings;
An upper position for holding the supported portion at the first position and an upper position for holding the supported portion at the second position. a link member in which the support portion swings between a lower position and a lower position;
One end is connected to the apparatus main body, the other end is connected to the pressure plate, and when the cover is in the closed position, the supported portion is separated from the support portion to move the pressure plate above the feeding portion. and an arm displaced between a first holding position for holding the pressure plate at the housing position of the cover and a second holding position for displaceably holding the pressure plate between the supply position and the non-supply position when the cover is in the open position. ,
a rail on one of the cover or the pressure plate;
a rib provided on the other of the cover or the pressure plate ,
The rail is configured such that the supported portion of the pressure plate, which is displaced as the cover swings from the closed position to the open position, continues until the cover reaches the open position after swinging from the closed position. and guiding the rib to pass through the first position between . The link member has a protruding portion that protrudes downward from an upstream end of the support portion in the sheet feeding direction,
When the link member is in the upper position, the protruding portion contacts the supported portion of the pressure plate that is displaced as the cover swings from the closed position to the open position. 2. The sheet feeding apparatus according to claim 1, wherein displacement to the downstream side in the sheet feeding direction is regulated. The feeding unit has a feeding roller and a separation roller arranged downstream of the feeding roller in the sheet feeding direction,
3. The sheet feeding apparatus according to claim 1 , wherein the pressure plate at the accommodation position is positioned above the feeding roller and the separation roller. comprising a retard roller facing the separation roller;
The link member is provided at a different position with respect to the retard roller in the rotation axis direction of the retard roller,
4. The sheet feeding device according to claim 3 , wherein the retard roller overlaps at least a part of the swinging range of the link member when viewed from the direction of the rotation shaft. 5. The pressure plate according to any one of claims 1 to 4 , wherein the supported portion is provided outside the sheet supporting surface in a width direction orthogonal to the sheet feeding direction. sheet feeder. a sheet feeding device according to any one of claims 1 to 5 ;
An image forming apparatus, comprising: an image forming unit that forms an image on a conveyed sheet.

Images