JP7562316B2 - Sheet feeding device and image forming apparatus - Google Patents

Description

The present invention relates to a sheet feeding device used in an image forming apparatus such as a copier, printer, facsimile, or multifunction machine having multiple functions of these, and to an image forming apparatus equipped with the same.

In image forming apparatuses, sheet feeding devices that feed sheets as recording materials to an image forming section are widely used. In order to ensure a feeding capacity in a limited space inside the device body, sheet feeding devices are known in which sheet storage sections that stack and store sheets are arranged adjacent to each other in the left-right direction of the device body, and sheets can be fed from each sheet storage section to the image forming section. In such sheet feeding devices, for example, a feeding section such as a pair of rollers that feeds sheets to the image forming section, a first sheet storage section, and a second sheet storage section are arranged adjacent to each other in the left-right direction. In this case, a horizontal transport path is arranged above the first sheet storage section, since the sheets stored in the second sheet storage section pass above the first sheet storage section and are transported to the feeding section. In addition, a horizontal transport path that can be pulled out from the device body to ensure jam processing in the horizontal transport path is known (see Patent Document 1).

JP 2011-63340 A

Incidentally, in order to facilitate the user's installation operation when installing the sheet storage unit or the transport unit in the installation position of the device body, it is conceivable to provide a retraction mechanism that applies a force to the sheet storage unit or the transport unit in a direction that retracts them toward the installation position. If such a retraction mechanism is provided in the sheet feeding device of Patent Document 1, there is a risk that the number of parts will increase and the configuration will become complicated if different retraction parts are provided for the sheet storage unit and the transport unit.

The present invention aims to provide a sheet feeding device and an image forming device that can suppress the complexity of the configuration while providing a retraction section.

The sheet feeding device of the present invention is a sheet feeding device that feeds sheets to an image forming section that forms an image on the sheet, the sheet feeding device including: a first sheet storage section that is movable between a first mounting position and a first drawn-out position pulled out from the first mounting position and that stores sheets on which an image is to be formed by the image forming section; a second sheet storage section that is arranged to be aligned horizontally with the first sheet storage section that is located at the first mounting position when the second sheet storage section is located at the second mounting position and that is movable separately from the first sheet storage section to a second drawn-out position pulled out from the second mounting position; a transport section that transports sheets fed from the second sheet storage section above the sheets stored in the first sheet storage section , the transport section being movable separately from the first sheet storage section between a third mounting position and a third drawn-out position pulled out from the third mounting position when the first sheet storage section is located at the first drawn-out position; and a pulling force that is applied to the first sheet storage section in a direction of pulling the first sheet storage section toward the first mounting position. and a retraction portion for retracting the sheet into the transport unit, the first sheet storage portion, the second sheet storage portion, and the transport unit are arranged such that when the first sheet storage portion is in the first installation position, the transport unit in the third installation position cannot be pulled out to the third pull-out position, the transport unit includes a guide portion for guiding the sheets to be transported, and when the first sheet storage portion moves from the first pull-out position toward the first installation position, a pressing portion of the first sheet storage portion, which is receiving the retraction force of the retraction portion, comes into contact with the transport unit and presses the transport unit , thereby moving the transport unit integrally with the first sheet storage portion toward the third installation position , and the pressing portion is located between an exterior surface of the first sheet storage portion and the guide portion in the orthogonal direction, overlaps the guide portion in the transport direction, and overlaps with the exterior surface of the first sheet storage portion when viewed from the orthogonal direction .

An image forming apparatus according to the present invention includes the sheet feeding device described above, and the image forming section that forms an image on the sheet fed by the sheet feeding device.
The image forming apparatus of the present invention further includes a first sheet storage section that is movable between a first mounting position and a first drawn-out position pulled out from the first mounting position and that stores sheets; a second sheet storage section that stores sheets and is arranged to be aligned horizontally with the first sheet storage section located at the first mounting position when the second sheet storage section is located at the second mounting position and that is movable separately from the first sheet storage section to a second drawn-out position pulled out from the second mounting position; a transport section that transports sheets fed from the second sheet storage section above the sheets stored in the first sheet storage section , the transport section being movable separately from the first sheet storage section between a third mounting position and a third drawn-out position pulled out from the third mounting position when the first sheet storage section is located at the first drawn-out position; rollers that are arranged to transport the sheets fed from the first sheet storage section and the sheets fed from the second sheet storage section and transported by the transport section; an image forming section that forms an image on the sheets transported by the rollers; and a pull section that pulls the sheets in a direction toward the first mounting position. and a retraction portion that applies a writing force to the first sheet accommodating portion, wherein the first sheet accommodating portion, the second sheet accommodating portion, and the conveying portion are arranged such that when the first sheet accommodating portion is in the first installation position, the conveying portion at the third installation position cannot be pulled out to the third pull-out position, and the conveying portion includes a guide portion that guides the sheets to be conveyed, and when the first sheet accommodating portion moves from the first pull-out position toward the first installation position, a pressing portion of the first sheet accommodating portion that receives the retraction force of the retraction portion comes into contact with the conveying portion and presses the conveying portion , thereby moving the conveying portion integrally with the first sheet accommodating portion toward the third installation position, and the pressing portion is located between an exterior surface of the first sheet accommodating portion and the guide portion in the orthogonal direction, overlaps the guide portion in the transport direction, and overlaps with the exterior surface of the first sheet accommodating portion when viewed from the orthogonal direction .

According to the present invention, it is possible to prevent the configuration from becoming too complicated while providing a retraction section.

1 is a schematic diagram illustrating an image forming apparatus according to a first embodiment. 3A and 3B are plan views showing the retraction mechanism according to the first embodiment, in which (a) is a state before retraction, (b) is a state immediately after the start of retraction, and (c) is a state after the end of retraction. 1A is a plan view of an image forming apparatus according to a first embodiment, in which a transport unit and a second sheet storage unit are positioned at a drawn-out position; FIG. 1A is a plan view of an image forming apparatus according to a first embodiment, in which a conveying unit and a second sheet storage unit are moved from a pulled-out position to a mounted position, FIG. 10A is a plan view of an image forming apparatus according to a second embodiment, in which a transport unit and a second sheet storage unit are positioned at the pulled-out position, FIG. 13A is a plan view of an image forming apparatus according to a second embodiment, in which a conveying unit and a second sheet storage unit are moved from a pulled-out position to a mounted position, FIG. 13A is a plan view of an image forming apparatus according to a modified example of the second embodiment, in which a conveying unit and a second sheet storage unit are positioned at the pulled-out position, FIG.

First Embodiment
A first embodiment of the present invention will be described in detail below with reference to Figures 1 to 4. First, an image forming apparatus equipped with a sheet feeding device according to an embodiment of the present invention will be described with reference to Figure 1. Note that Figure 1 is a schematic cross-sectional view showing a laser beam printer as an image forming apparatus 1 according to this embodiment, as viewed from the front. Note that in this embodiment, the front side and the back side of the image forming apparatus 1 are defined as the front-rear direction, and the left and right sides when facing the front of the image forming apparatus 1 are defined as the left and right directions.

[Image forming apparatus]
1, an image forming apparatus 1, for example a full-color laser beam printer, includes an apparatus main body 10, which is an example of a housing. The apparatus main body 10 includes a control unit 11 that controls each unit of the apparatus, a process unit 20, a fixing unit 12, and an image reading device 13 that is disposed substantially horizontally above the apparatus main body 10.

The device body 10 is provided with a discharge space Sp for discharging sheets below the image reading device 13. A toner cartridge 21 is disposed below the discharge space Sp, and multiple (three in this embodiment) sheet feeding devices 2, 3, and 4 are disposed in the lower part of the device body 10. The device body 10 is provided with an installation space (not shown) in which sheet cassettes 102 and 103 described below in the sheet feeding devices 2 and 3 can be installed and removed. Furthermore, the device body 10 is provided with an installation space (not shown) in which sheet cassettes 41 and 42 described below in the sheet feeding device 4 can be installed and removed.

The process unit 20 uses a four-drum full-color system and has a laser scanner 22 and four process cartridges 23 that form toner images in four colors: yellow (Y), magenta (M), cyan (C), and black (K).

Here, each process cartridge 23 has a photosensitive drum 24 as a photosensitive member, a charger 25 as a charging means, a developer 26 as a developing means, and a cleaner (not shown) as a cleaning means. In addition, the process section 20 has an intermediate transfer unit 27 above the process cartridge 23.

The intermediate transfer unit 27 has an intermediate transfer belt 30 wound around a drive roller 28 and a tension roller 29. The intermediate transfer unit 27 also has a primary transfer roller 31 that is disposed inside the intermediate transfer belt 30 and abuts against the inner surface of the intermediate transfer belt 30 at a position facing the photosensitive drum 24. The intermediate transfer belt 30 is made of a film-like member, abuts against each photosensitive drum 24, and is rotated in the direction of the arrow by a drive roller 28 that is driven by a drive unit (not shown).

When a positive transfer bias is applied from the primary transfer roller 31 to the intermediate transfer belt 30, the negative color toner images on the photosensitive drum 24 are sequentially transferred in a multi-layer manner onto the intermediate transfer belt 30. As a result, a color image is formed on the intermediate transfer belt 30. A secondary transfer roller 32 is disposed opposite the drive roller 28, and transfers the color image formed on the intermediate transfer belt 30 onto the sheet S, which is a recording material. The secondary transfer section is constituted by the secondary transfer nip N formed by the drive roller 28 and the secondary transfer roller 32 pressed against it.

The fixing unit 12 is disposed downstream of the secondary transfer roller 32 in the sheet transport direction, and above the fixing unit 12, a first discharge roller pair 33, a second discharge roller pair 34, and a double-sided reversing unit 35 as a reversing discharge unit are disposed. The process unit 20, the secondary transfer nip N, and the fixing unit 12 constitute the image forming unit 14 that forms an image on the sheet S fed by the sheet feeding devices 2 to 4.

In the above configuration, the image information read by the image reading device 13 or the image information input from an external device such as a personal computer (PC) (not shown) is subjected to image processing, converted into an electrical signal, and transmitted to the laser scanner 22 in the processing unit 20.

Then, in the process section 20, the surface of the photosensitive drum 24 of each process cartridge 23 is scanned with laser light corresponding to the image information of the yellow, magenta, cyan and black component colors emitted from the laser scanner 22. As a result, the surface of the photosensitive drum 24, which is uniformly charged to a predetermined polarity and potential by the charger 25, is sequentially exposed, and electrostatic latent images of yellow, magenta, cyan and black are sequentially formed on the photosensitive drum of each process cartridge 23, respectively.

The electrostatic latent images are then developed and visualized with yellow, magenta, cyan and black toners, and the toner images of each color on each photosensitive drum are transferred in sequence to the intermediate transfer belt 30 in a superimposed manner by a primary transfer bias applied to the primary transfer roller 31. This forms a toner image on the intermediate transfer belt 30.

Meanwhile, the sheet S sent from one of the sheet feeding devices 2 to 4 passes through the registration roller pair 36 and is sent to the secondary transfer nip portion N. Here, the registration roller pair 36 abuts the sheet S and forms a loop, so that the leading edge of the sheet S follows the nip portion and corrects skew. In the secondary transfer nip portion N, the toner image formed in the process unit 20 is secondarily transferred onto the sheet S all at once.

The sheet S onto which the toner image has been secondarily transferred in this manner is transported to the fixing unit 12, where it is heated and pressurized, and the toner image is fixed as a color image. After this, the sheet S onto which the color image has been fixed is discharged by the first discharge roller pair 33 into the discharge space Sp, and is stacked on the stacking unit 37 provided within the discharge space Sp.

[Outline of Sheet Feeding Device]
The sheet feeding device 2 includes a sheet cassette 102 that stores sheets S, and a sheet feeding section 110 that feeds the sheets S stored in the sheet cassette 102 toward a downstream pull-out roller pair 114. The sheet feeding section 110 includes a pickup roller 111, a feed roller 112, and a retard roller 113 that are disposed at an upper downstream position in the sheet feeding direction.

The pickup roller 111 is supported rotatably by an arm (not shown) that can rotate around the feed roller 112, and feeds out the sheet S by rotating while pressing against the sheet S stored in the sheet cassette 102. The sheet cassette 102 is supported so that it can be attached and removed in the front-rear direction of the device main body 10.

The sheet feeding device 3 includes a sheet cassette 103 that stores sheets S, and a sheet feeding section 120 that sends out the sheets S stored in the sheet cassette 103 toward a downstream pull-out roller pair 124. The sheet feeding section 120 includes a pickup roller 121, a feed roller 122, and a retard roller 123 that are located at the upper downstream side in the sheet feeding direction.

The pickup roller 121 is supported rotatably by an arm (not shown) that can rotate around the feed roller 122, and feeds out the sheet S by rotating while pressing against the sheet S stored in the sheet cassette 103. The sheet cassette 103 is supported so that it can be attached and removed in the front-rear direction of the device body 10.

The sheet feeding device 4 has a first sheet cassette 41, which is an example of a first sheet storage section that stores sheets S, a second sheet cassette 42, which is an example of a second sheet storage section, sheet feeding sections 140, 150, and a feeding section 130. The feeding section 130, the first sheet cassette 41, and the second sheet cassette 42 are arranged in order in the left-right direction (horizontal direction) of the device main body 10. In this embodiment, the first sheet cassette 41 is arranged on the right side of the device main body 10, and the second sheet cassette 42 is arranged on the left side thereof.

The sheet feeding section 140 has a pickup roller 141, a feed roller 142, and a retard roller 143 arranged in the upper downstream portion in the sheet feeding direction. The sheet feeding section 140 sends out the sheet S stored in the first sheet cassette 41 toward the downstream pull-out roller pair 144. The sheet feeding section 150 has a pickup roller 151, a feed roller 152, and a retard roller 153 arranged in the upper downstream portion in the sheet feeding direction. The sheet feeding section 150 sends out the sheet S stored in the second sheet cassette 42 toward the downstream pull-out roller pair 154. The sheet cassettes 41 and 42 are supported so that they can be attached and removed in the front-rear direction of the device main body 10.

That is, the first sheet cassette 41 is disposed horizontally adjacent to the feeding section 130 and is movable between a first mounting position mounted in the device body 10 and a first pull-out position pulled out from the device body 10. The second sheet cassette 42 is disposed horizontally adjacent to the first sheet cassette 41 on the opposite side of the feeding section 130 and is movable between a second mounting position mounted in the device body 10 and a second pull-out position pulled out from the device body 10. In this embodiment, the first sheet cassette 41 and the second sheet cassette 42 are each independently movable relative to the device body 10.

The feeding section 130 has a pair of feeding rollers 131, and feeds the sheets fed from each of the sheet feeding sections 140 and 150 to the image forming section 14. Here, since the sheet feeding section 150 and the feeding section 130 are arranged via the first sheet cassette 41, a horizontal transport path is provided above the first sheet cassette 41 for transporting the sheet S from the sheet feeding section 150 to the feeding section 130.

In this embodiment, the horizontal conveying path is configured by a conveying unit 50, which is an example of a conveying section. The conveying unit 50 has an upper conveying roller 51 and a lower conveying roller 52, which are arranged above and below the conveying path, and an upper guide plate 53, which is an example of a cover member that rotatably holds the upper conveying roller 51. A pair of conveying rollers 155 is provided between the conveying unit 50 and the feeding section 130. The conveying unit 50 is detachably mounted by moving in the front-rear direction relative to the mounting section 10a formed in the device main body 10. When the conveying unit 50 is pulled out from the device main body 10, the upper guide plate 53 can be opened by swinging it above the sheet conveying path (see FIG. 3). This allows the sheet jam in the conveying unit 50 to be processed. The operation of attaching and detaching the conveying unit 50 to and from the device main body 10 will be described later.

When the image forming operation starts, the sheets S are separated and fed one by one from the sheet cassettes 102, 103, 41, and 42 by the sheet feeding units 110, 120, 140, and 150. The sheets S fed by the pickup rollers 111, 121, 131, and 141 are transported by the corresponding feed rollers 112, 122, 132, and 142. If multiple sheets S are fed at once, the second and subsequent sheets S are returned to the sheet cassette by the corresponding retard rollers 113, 123, 133, and 143. The separated and transported sheets S are sent downstream by the pull-out roller pairs 114, 124, 134, and 144, and transported to the registration roller pair 36.

[Retraction mechanism]
This image forming apparatus 1 has a retraction mechanism capable of retracting each of the sheet cassettes 102, 103, 41, and 42 into the apparatus main body 10. Since all of them have the same configuration, a retraction mechanism 60 that is an example of a retraction section capable of retracting the first sheet cassette 41 into the apparatus main body 10 will be described here. As shown in Fig. 2, the retraction mechanism 60 is disposed inside the apparatus main body 10 downstream of the movement direction in which the transport unit 50 moves from the third pull-out position to the third mounting position when mounting the transport unit 50 in the mounting section 10a.

2, the retraction mechanism 60 is provided on the rear frame 10b of the device body 10, and includes a case member 61, a toggle arm 62, and a toggle spring 63. The case member 61 is attached to the rear frame 10b of the device body 10. The toggle arm 62 is supported by a swing shaft 64 so as to be swingable relative to the case member 61, and includes a locking hook 65 that can be engaged with the locking pin 43 of the first sheet cassette 41. The toggle spring 63 is, for example, a tension coil spring, and is stretched between the toggle arm 62 and the case member 61. On the other hand, a substantially cylindrical locking pin 43 that can be engaged with the locking hook 65 of the retraction mechanism 60 is provided on the frame at the rear side in the insertion direction of the first sheet cassette 41 into the device body 10.

2(a), when the first sheet cassette 41 is not housed in the device main body 10, the retraction mechanism 60 has the locking hook 65 at the tip of the toggle arm 62 in the standby position. When the first sheet cassette 41 is inserted into the device main body 10 and the locking pin 43 reaches the retraction mechanism 60, the locking pin 43 engages with the locking hook 65 as shown in FIG. 2(b). When the first sheet cassette 41 is further inserted, the toggle arm 62 rotates counterclockwise. At this time, when the toggle spring 63 exceeds the line (indicated by the dashed line in the figure) connecting the base end 63a of the toggle spring 63, which is the neutral point, and the swing shaft 64, a retraction force is generated, and the first sheet cassette 41 is automatically retracted to the mounting position by the spring force as shown in FIG. 2(c). In this way, when the retraction mechanism 60 moves the first sheet cassette 41 to the mounting position of the device main body 10, it generates a force to move in the mounting direction. This generated force is called the retraction force. The position at which the retraction force occurs will be explained later.

[Attachment and detachment of sheet cassette and transport unit]
3A to 3C, a pressing portion 45 is formed on the upper portion on the front side of the first sheet cassette 41. Also, in the transport unit 50, a pressure receiving portion 55 is formed on the rear side of the pressing portion 45. Therefore, when the first sheet cassette 41 moves to the mounting position relative to the pulled-out transport unit 50, the pressing portion 45 of the first sheet cassette 41 presses the pressure receiving portion 55 of the transport unit 50, and thus the first sheet cassette 41 moves to the mounting position in conjunction with the pulled-out transport unit 50. In other words, the first sheet cassette 41 can move to the mounting position together with the pulled-out transport unit 50.

In this embodiment, the transport unit 50 can move along the movement direction of the first sheet cassette 41 to a third mounting position where it is mounted in the mounting section 10a and a third pull-out position where it is pulled out from the mounting section 10a. When the first sheet cassette 41 is located at the first pull-out position, the transport unit 50 can move to the third mounting position and the third pull-out position separately from the first sheet cassette 41. When the first sheet cassette 41 moves from the first pull-out position toward the first mounting position, the transport unit 50 is pressed by the first sheet cassette 41 and moves integrally toward the third mounting position. When the first sheet cassette 41 is located at the first mounting position, the transport unit 50 is restricted from moving toward the third pull-out position by the first sheet cassette 41 at the third mounting position.

When the transport unit 50 is in the third mounting position, the first sheet cassette 41 can be moved and attached to the device body 10 by itself. The second sheet cassette 42 can be moved and attached to the device body 10 by itself, regardless of the attachment/detachment state of the first sheet cassette 41 and the transport unit 50 to the device body 10.

[Upper guide plate opening/closing position and retraction force generation position]
The state in which the upper guide plate 53 can be opened is shown in FIG. 3, and the state in which it cannot be opened is shown in FIG. 4. Here, the position of the rear end of the upper guide plate 53 in the front-rear direction is defined as position P1. Also, the position of the front-rear direction on the front side of the mounting part 10a where the transport unit 50 is mounted to the device main body 10 is defined as position P2. In this case, the condition for the upper guide plate 53 to be in the open state is when the position P1 of the upper guide plate 53 is located closer to the main body than the position P2 of the mounting part 10a, as shown in FIG. 2(a). Also, when the upper guide plate 53 is in the open state, it is impossible to mount the transport unit 50 to the device main body 10 because the upper guide plate 53 interferes with the front part of the device main body 10 at the entrance of the mounting part 10a. On the other hand, when the upper guide plate 53 is in the closed state, the transport unit 50 can be inserted into the mounting part 10a, and can be moved to the mounting position of the device main body 10, as shown in FIG. 3(a). That is, when the transport unit 50 is opened, at least a portion of the upper guide plate 53 is positioned outside the mounting portion 10a when the transport unit 50 is viewed from the front-rear direction.

When the transport unit 50 is moved from the third pull-out position toward the third mounting position by the movement of the first sheet cassette 41, the movement range of the first sheet cassette 41 until position P1 reaches position P2 is defined as the second range Ar2. That is, the upper guide plate 53 can be opened when the second sheet cassette 42 is located in the second range Ar2.

Here, if the retraction force exerted by the retraction mechanism 60 on the first sheet cassette 41 and the transport unit 50 occurs when the position P1 of the upper guide plate 53 is closer to the front than the position P2, the upper guide plate 53 of the transport unit 50 will interfere with the front part of the device body 10. In addition, in this state, for an operator who opens the upper guide plate 53 and processes the jammed sheet S in the transport unit 50, the operator must perform the work while keeping the transport unit 50 stationary so that the transport unit 50 is not retracted by the retraction force. This significantly deteriorates the workability. Therefore, in this embodiment, the generation area of the retraction force exerted on the first sheet cassette 41 is set to a position where the position P1 of the upper guide plate 53 is closer to the back of the main body than the position P2.

2, the retraction force is generated by the retraction mechanism 60 when the latch pin 43 reaches the retraction mechanism 60 and engages with the latch hook 65, the toggle arm 62 rotates counterclockwise, and the toggle spring 63 passes the pivot shaft 57, which is in neutral rotation. This means that the retraction force generation position by the retraction mechanism 60 is the position where the position P1 of the upper guide plate 53 is located further back than the position P2, as shown in FIG. 4(a). Here, the range of positions where the retraction mechanism 60 retracts the first sheet cassette 41 toward the first mounting position is the first range Ar1 between the first mounting position and the first pull-out position.

The first range Ar1 in which the retraction mechanism 60 generates a retraction force and the second range Ar2 in which the upper guide plate 53 can be opened are set so as not to overlap with each other with respect to the movement range of the first sheet cassette 41. That is, the conditions for the region in which the retraction force is generated by the retraction mechanism 60 are as follows. The position in which the retraction force is not generated is when position P1 is located closer to the front of the device body 10 than position P2, and the position in which the retraction force can be generated is when position P1 is located closer to the back of the device body 10 than position P2.

[Magnitude of pulling force]
In this embodiment, the retraction mechanism 60 may retract both the first sheet cassette 41 and the transport unit 50 at the same time. In this case, the load is large, making it difficult to reliably return the first sheet cassette 41 and the transport unit 50 to the mounting position. Therefore, the retraction force of the retraction mechanism 60 is set to be equal to or greater than the sum of the force required to move the first sheet cassette 41 to the first mounting position in the sheet storage state and the force required to move the transport unit 50 to the third mounting position. In other words, when the retraction force of the retraction mechanism 60 is F1, the force required to move the first sheet cassette 41 to the mounting position is F2, and the force required to move the transport unit 50 to the mounting position is F3, the retraction force is set to satisfy the relationship F1≧F2+F3.

As described above, according to the image forming device 1 of this embodiment, the transport unit 50 can be retracted to the third mounting position by retracting the first sheet cassette 41 to the first mounting position, so one retraction mechanism 60 can be used for both. Therefore, compared to the case where a retraction mechanism 60 is provided for both the first sheet cassette 41 and the transport unit 50, an increase in the number of parts and a complicated configuration can be suppressed.

In addition, according to the image forming apparatus 1 of this embodiment, the first range Ar1 where the retraction mechanism 60 generates a retraction force and the second range Ar2 where the upper guide plate 53 can be opened are set so as not to overlap with each other with respect to the movement range of the first sheet cassette 41. Therefore, it is possible to prevent the upper guide plate 53 from interfering with the front part of the device main body 10 when the transport unit 50 is retracted into the mounting part 10a while the upper guide plate 53 is open. As a result, when the upper guide plate 53 is opened to process the jammed sheet S in the transport unit 50, it is not necessary to perform the work while keeping the transport unit 50 stationary so that the transport unit 50 is not retracted by the retraction force, and the workability can be improved. In other words, after removing the jammed sheet S, the first sheet cassette 41 and the transport unit 50 can be reliably returned to the mounting position. Therefore, the retraction force of the retraction mechanism 60 makes it easy for the user to mount the sheet S, while ensuring the workability of the jam processing of the transport unit 50.

In addition, according to the image forming device 1 of this embodiment, the retraction force of the retraction mechanism 60 is greater than or equal to the sum of the force required to move the first sheet cassette 41 to the first mounting position and the force required to move the transport unit 50 to the third mounting position. Therefore, even if the load increases when retracting both the first sheet cassette 41 and the transport unit 50 at the same time, they can be positioned at the mounting position with high accuracy, ensuring user operability.

Second Embodiment
Next, the sheet feeding device 104 of the image forming apparatus 101 according to the second embodiment of the present invention will be described in detail with reference to Fig. 5 and Fig. 6. In this embodiment, the configuration is different from that of the first embodiment in that the transport unit 50 is linked to the second sheet cassette 42 instead of the first sheet cassette 41. However, other configurations are the same as those of the first embodiment, so the same reference numerals are used and detailed description is omitted.

[Attachment and detachment of sheet cassette and transport unit]
5A to 5C, a pressing portion 44 is formed on the portion of the second sheet cassette 42 facing the transport unit 50. Also, a pressure receiving portion 54 is formed on the portion of the transport unit 50 facing the second sheet cassette 42, which is located on the rear side of the apparatus main body 10 from the pressing portion 44. Therefore, when the second sheet cassette 42 moves to the mounting position relative to the pulled-out transport unit 50, the pressing portion 44 of the second sheet cassette 42 presses the pressure receiving portion 54 of the transport unit 50, thereby moving in conjunction with the second sheet cassette 42 to the mounting position. In other words, the second sheet cassette 42 is capable of moving to the mounting position together with the pulled-out transport unit 50.

In this embodiment, when the second sheet cassette 42 is located at the second pull-out position, the transport unit 50 can move to the third mounting position and the third pull-out position separately from the second sheet cassette 42. When the second sheet cassette 42 moves from the second pull-out position toward the second mounting position, the transport unit 50 is pressed by the second sheet cassette 42 and moves integrally with the second sheet cassette 42 toward the third mounting position. When the second sheet cassette 42 is located at the second mounting position, the transport unit 50 is restricted from moving toward the third pull-out position by the second sheet cassette 42 at the third mounting position.

When the transport unit 50 is in the third mounting position, the second sheet cassette 42 can be moved and attached to the device body 10 by itself. The first sheet cassette 41 can be moved and attached to the device body 10 by itself, regardless of the attachment/detachment state of the second sheet cassette 42 and the transport unit 50 to the device body 10.

[Upper guide plate opening/closing position and retraction force generation position]
5 shows a state in which the upper guide plate 53 can be opened, and FIG 6 shows a state in which the upper guide plate 53 cannot be opened. In this embodiment, when the transport unit 50 is moved from the third pull-out position to the third installation position by the movement of the second sheet cassette 42, the movement range of the second sheet cassette 42 until position P1 reaches position P2 is defined as a second range Ar2. Also, the range of positions in which the retraction mechanism 60 retracts the second sheet cassette 42 toward the second installation position is defined as a first range Ar1 between the second installation position and the second pull-out position.

As in the first embodiment, the movement range of the second sheet cassette 42 is set so that the first range Ar1 in which the retraction mechanism 60 generates a retraction force and the second range Ar2 in which the upper guide plate 53 can be opened do not overlap.

[Magnitude of pulling force]
In this embodiment, the retraction mechanism 60 may retract both the second sheet cassette 42 and the transport unit 50 at the same time. In this case, the load is large, making it difficult to reliably return the second sheet cassette 42 and the transport unit 50 to the mounting position. Therefore, the retraction force of the retraction mechanism 60 is set to be equal to or greater than the sum of the force required to move the second sheet cassette 42 to the second mounting position in the sheet storage state and the force required to move the transport unit 50 to the third mounting position. In other words, when the retraction force of the retraction mechanism 60 is F1, the force required to move the second sheet cassette 42 to the mounting position is F4, and the force required to move the transport unit 50 to the mounting position is F3, the retraction force is set to satisfy the relationship F1≧F4+F3.

As described above, according to the image forming apparatus 101 of this embodiment, the transport unit 50 can be retracted to the third mounting position by retracting the second sheet cassette 42 to the second mounting position, so one retraction mechanism 60 can be used for both. Therefore, compared to the case where a retraction mechanism 60 is provided for both the second sheet cassette 42 and the transport unit 50, an increase in the number of parts and a complicated configuration can be suppressed.

In the above embodiment, the second sheet cassette 42 and the transport unit 50 are described as being capable of moving separately, but the present invention is not limited thereto. For example, the second sheet cassette 42 and the transport unit 50 may be moved as one unit. In this case, as shown in FIG. 7, the transport unit 50 is integrated with the second sheet cassette 42 and moves together with the second sheet cassette 42. In this case, the relationship between the first range Ar1 where the retraction mechanism 60 generates a retraction force and the second range Ar2 where the upper guide plate 53 can be opened is the same, so that the same effect as described above can be obtained. That is, the transport unit 50 may be movable along the movement direction of the second sheet cassette 42 to the third mounting position and the third drawing position, regardless of whether it is separate from or integrated with the second sheet cassette 42. Furthermore, regardless of whether the transport unit 50 is separate from or integrated with the second sheet cassette 42, it is sufficient that the transport unit 50 moves integrally with the second sheet cassette 42 toward the third mounting position when the second sheet cassette 42 moves from the second pull-out position toward the second mounting position.

<Other embodiments>
In the above embodiment, the upper guide plate 53 is used as a cover member that allows the sheet transport path of the transport unit 50 to be opened, but the present invention is not limited to this. For example, a cover member separate from the transport member may be used.

In the above embodiment, the retraction mechanism 60 is provided in the device main body 10, but this is not limited thereto, and it may be provided, for example, on the transport unit 50 side. In addition, the toggle spring 63 made of a tension coil spring is used as the retraction force generating means, but this is not limited thereto, and other biasing means can be widely applied.

1,101...image forming apparatus, 4,104...sheet feeding apparatus, 10...apparatus body (housing), 10a...mounting section, 14...image forming section, 41...first sheet cassette (first sheet storage section), 42...second sheet cassette (second sheet storage section), 50...transport unit (transport section), 53...upper guide plate (covering member), 60...retraction mechanism (retraction section), 130...feeding section, Ar1...first range, Ar2...second range, S...sheet

Claims (8)

A sheet feeding device that feeds a sheet to an image forming section that forms an image on the sheet,
a first sheet storage section that is movable between a first mounting position and a first drawn-out position drawn out from the first mounting position and that stores a sheet on which an image is formed by the image forming section;
a second sheet storage section for storing a sheet on which an image is formed by the image forming section, the second sheet storage section being arranged to be aligned horizontally with the first sheet storage section positioned at the first mounting position when the second sheet storage section is positioned at the second mounting position and being movable separately from the first sheet storage section to a second pull-out position pulled out from the second mounting position;
a conveying section that conveys a sheet fed from the second sheet accommodating section above the sheet accommodated in the first sheet accommodating section, the conveying section being movable between a third mounting position and a third pulled-out position pulled out from the third mounting position separately from the first sheet accommodating section when the first sheet accommodating section is located at the first pulled-out position ;
a retraction portion that applies a retraction force to the first sheet accommodating portion in a direction to retract the first sheet accommodating portion toward the first mounting position,
the first sheet storage unit, the second sheet storage unit, and the conveying unit are movable along a direction perpendicular to a conveying direction in which the conveying unit conveys the sheet,
the first sheet accommodating unit and the conveying unit are arranged such that, in a state in which the first sheet accommodating unit is in the first mounting position, the conveying unit in the third mounting position cannot be drawn out to the third drawn-out position;
the conveying section includes a guide section that guides a sheet to be conveyed,
when the first sheet accommodating unit moves from the first pulled-out position toward the first installed position, a pressing portion of the first sheet accommodating unit receiving the retracting force of the retracting portion comes into contact with the conveying unit and presses the conveying unit , so that the conveying unit is moved integrally with the first sheet accommodating unit toward the third installed position ;
the pressing portion is located between an exterior surface of the first sheet accommodating portion and the guide portion in the perpendicular direction, overlaps with the guide portion in the conveying direction, and overlaps with the exterior surface of the first sheet accommodating portion when viewed from the perpendicular direction.
A sheet feeding device comprising: a housing provided with a mounting portion for mounting the conveying unit;
the retraction portion applies the retracting force to the first sheet accommodating portion when the first sheet accommodating portion is located in a first range between the first mounting position and the first drawn-out position,
the conveying section has a cover member that can open the sheet conveying path of the conveying section upward and that, when opened, is at least partially positioned outside the mounting section when the conveying section is viewed from the mounting direction;
the covering member is openable in a state in which the conveying unit is moved from the third pull-out position toward the third mounting position by the movement of the first sheet accommodating unit and the first sheet accommodating unit is positioned in a second range in which the first sheet accommodating unit is not subjected to the retraction force of the retraction unit,
The first range and the second range do not overlap.
2. The sheet feeding apparatus according to claim 1, wherein the sheet feeding apparatus comprises: a guide portion of the conveying portion guides an upper surface of a sheet to be conveyed in a guide position, and can rotate about a rotation center parallel to a pull-out direction for pulling out the conveying portion from the guide position to an open position for opening a conveying path along which the sheet is conveyed ;
When the conveying section is in a region from the third mounting position to a predetermined position in the pull-out direction, the guide section cannot move to the open position,
When the guide portion is in a position pulled out in the pull-out direction from the predetermined position, the guide portion can move from the guide position to the open position,
even when the first sheet accommodating portion is located at any position that the first sheet accommodating portion can take in a state in which the conveying portion is located at a position pulled out in the pull-out direction from the predetermined position, the pull-in portion does not apply the pull-in force to the first sheet accommodating portion.
2. The sheet feeding apparatus according to claim 1, wherein the sheet feeding apparatus comprises: the retraction section has a retraction force equal to or greater than a sum of a force required to move the first sheet accommodating section in a sheet storage state to the first mounting position and a force required to move the conveying section to the third mounting position.
4. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet conveying device. a roller for conveying the sheet fed from the first sheet storage unit and the sheet fed from the second sheet storage unit and conveyed by the conveying unit, toward the image forming unit;
5. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet conveying device. a cassette that is disposed above the first sheet storage section, the second sheet storage section, and the conveying section and that stores a sheet on which an image is formed by the image forming section;
the cassette is arranged so as to overlap the first sheet storage unit in a horizontal direction, so as to overlap the second sheet storage unit in a horizontal direction, and so as to overlap the conveying unit in a horizontal direction;
6. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet conveying device. The sheet feeding device according to claim 1 ,
an image forming unit that forms an image on the sheet fed by the sheet feeding device,
1. An image forming apparatus comprising: a first sheet storage section that is movable between a first mounting position and a first drawn-out position drawn out from the first mounting position and that stores a sheet;
a second sheet storage section for storing sheets, the second sheet storage section being arranged to be aligned horizontally with the first sheet storage section positioned at the first mounting position when the second sheet storage section is positioned at the second mounting position, and being movable separately from the first sheet storage section to a second drawn-out position drawn out from the second mounting position;
a conveying section that conveys a sheet fed from the second sheet accommodating section above the sheet accommodated in the first sheet accommodating section, the conveying section being movable between a third mounting position and a third pull-out position pulled out from the third mounting position separately from the first sheet accommodating section when the first sheet accommodating section is located at the first pull-out position ;
a roller arranged to convey the sheet fed from the first sheet storage unit and the sheet fed from the second sheet storage unit and conveyed by the conveying unit;
an image forming section for forming an image on the sheet conveyed by the roller;
a retraction portion that applies a retraction force to the first sheet accommodating portion in a direction to retract the first sheet accommodating portion toward the first mounting position,
the first sheet storage unit, the second sheet storage unit, and the conveying unit are movable along a direction perpendicular to a conveying direction in which the conveying unit conveys the sheet,
the first sheet accommodating unit and the conveying unit are arranged such that, in a state in which the first sheet accommodating unit is in the first mounting position, the conveying unit in the third mounting position cannot be drawn out to the third drawn-out position;
the conveying section includes a guide section that guides a sheet to be conveyed,
when the first sheet accommodating unit moves from the first pulled-out position toward the first installed position, a pressing portion of the first sheet accommodating unit receiving the retracting force of the retracting portion comes into contact with the conveying unit and presses the conveying unit , so that the conveying unit is moved integrally with the first sheet accommodating unit toward the third installed position ;
the pressing portion is located between an exterior surface of the first sheet accommodating portion and the guide portion in the perpendicular direction, overlaps with the guide portion in the conveying direction, and overlaps with the exterior surface of the first sheet accommodating portion when viewed from the perpendicular direction.
1. An image forming apparatus comprising:

Images