JP2001019189A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of miniaturization while stable feed performance of a sheet can be ensured. SOLUTION: This device has a sheet storage part 13 and a feed means 15 feeding a sheet S stored in the sheet storage part 13, also a sheet feed position of a sheet feeder B mounted in a side part in a cassette draw-out direction side of a device main body 41 and a sheet feed position of a cassette 10 storing the sheet S also to be mounted capable of mounting/removing in the device main body are set so as to be almost the same position. This sheet feeder B can be moved to a position not obstructing mounting/demounting of the cassette 10 in the case that it is drawn out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine or a printer, and more particularly to a sheet feeding apparatus provided in an image forming apparatus and feeding a sheet to an image forming section.

[0002]

2. Description of the Related Art In a conventional image forming apparatus such as a copying machine or a printer, in the case of an apparatus which requires use of various types of sheets, the apparatus is provided separately from a sheet cassette provided in the apparatus main body or additionally provided. In some cases, a multi-feeding device including a sheet storage unit and a feeding unit is provided.

FIG. 5 shows an example of an image forming apparatus provided with such a multi-feeding apparatus. In FIG. 5, reference numeral 50 denotes a sheet cassette detachably mounted on an apparatus main body 51; This is a multi-feeding device including a storage section 61 and a feeding means 62.

The sheet S stored in the sheet cassette 50 is sent out by a feed roller 52 to a transport path R extending substantially vertically, and then is transported to the image forming section 53 through the transport path R. After an image is formed in the image forming section 53, the sheet is discharged via a fixing device 54 and a sheet discharging roller 55.

On the other hand, after the sheet S stored in the sheet storage portion 61 of the multi-feeding device 60 is sent out by the feeding means 62, first, the sheet S provided between the sheet storage portion 61 and the conveyance path R is fed. Guided to the transport path R by the path R1,
Thereafter, the sheet is conveyed to the image forming section 53 through the conveyance path R.

Incidentally, such a sheet cassette 50 is used.
In the image forming apparatus provided with the multi-feeding device 60, when the transport path R extends in a substantially vertical direction, the multi-feeding device 60 and the sheet cassette 50 sandwich the transport path R as shown in FIG. Be placed.

In this case, if the direction of attachment / detachment of the sheet cassette 50 is in the direction of the multi-feeding device 60 as shown by an arrow, the multi-feeding device 60 does not affect the operation of attaching / detaching the sheet cassette 50. Sheet cassette 50
Therefore, the sheet cassette 50 and the multi-sheet feeding device 60 are often arranged at different levels in the vertical direction.

[0008]

In a conventional image forming apparatus having such a sheet cassette 50 and a multi-sheet feeding device 60, the multi-sheet feeding device 60 stably feeds many types of sheets. Since the sheet is required to be fed, for example, even when a sheet such as a thick and hard cardboard or an envelope is fed, a feeding path R1 is provided so as to reduce the resistance due to the bending of the sheet and stably feed the sheet. Needs to have a large curvature.

However, if the curvature of the feed passage R1 is increased as described above, the height dimension of the feed passage R1 increases. Then, as described above, the sheet cassette 50
The multi-sheet feeding device 6
In the case where 0s are arranged stepwise in the vertical direction, there is a problem that if the height of the feeding passage R1 is increased, the height of the apparatus is also increased.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an image forming apparatus which can ensure stable sheet feeding performance and can be downsized. It is the purpose.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an image forming apparatus for forming an image on a sheet conveyed to an image forming section, a cassette accommodating the sheet and being detachably mounted in an apparatus body. A first feeding unit provided in the apparatus main body for feeding sheets stored in the cassette, a sheet storage unit for storing the sheets, and a second feeding unit for feeding the sheets stored in the sheet storage units And a sheet feeding device attached to a side of the apparatus main body on a cassette drawer side, wherein a sheet feeding position of the sheet feeding device and a sheet feeding position of the cassette are provided. Are provided at substantially the same position in the height direction, and the sheet feeding device can be moved to a position which does not hinder the drawing of the cassette when the cassette is drawn.

Further, according to the present invention, the first feeding means feeds the sheet from the sheet feeding device side of the cassette, and the second feeding means feeds the sheet from the cassette side of the sheet storage portion. It is characterized by being sent.

Further, according to the present invention, the sheet feeding apparatus is rotatably supported by the apparatus main body, and can feed a sheet when the sheet storage section is in a substantially horizontal state. The cassette can be pulled out when the cassette is turned upright.

The present invention further comprises a transport path for transporting the sheets sent from the cassette and the sheet feeding device to the image forming section, respectively, wherein the sheet fed from the sheet feeding device is transported by the transport path. The cassette is provided with a feeding passage at an end of the cassette on the sheet feeding device side.

The present invention further comprises a substantially vertically extending conveyance path for conveying the sheet sent from the cassette and the sheet feeding device, respectively, and the image forming section is arranged in the substantially vertically extending conveyance path. It is characterized by having done.

Further, the present invention is characterized in that the apparatus main body is provided with a driving means for driving a second feeding means of the sheet feeding apparatus.

Further, according to the present invention, there is provided the driving device, wherein:
And a gear train for transmitting a driving force to the sheet feeding device, and one gear in the gear train is arranged at a rotation fulcrum of the sheet feeding device.

Further, according to the present invention, the driving means drives a second feeding means of the sheet feeding apparatus and also drives a first feeding means provided in the apparatus main body. It is a feature.

Further, according to the present invention, when the sheet feeding device is moved to a position where it does not hinder the drawer of the cassette, the drive transmission from the driving means to the first feeding means is interrupted. It is characterized by the following.

Further, the present invention is characterized in that the sheet feeding device is moved to a position substantially horizontal to the cassette and to a position which does not hinder the attachment / detachment of the cassette in conjunction with the attaching / detaching operation of the cassette. is there.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a printer which is an example of an image forming apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 40 denotes a printer, 41 denotes a printer main body (hereinafter referred to as a main body), and the printer 40 includes an image forming section 3, a fixing means 8, a cassette sheet feeding apparatus A, and a multi-feeding apparatus. B.

Here, the image forming section 3 of the present embodiment
A photosensitive drum 4 which is an image carrier rotating in the direction of the arrow,
An optical system 5 for forming a latent image by irradiating the drum surface with laser light in accordance with image information; developing means 6 for developing the latent image with toner to make it visible; and a transfer roller for transferring the toner image to a sheet 7 is provided.

The cassette sheet feeder A is a sheet cassette 10 for storing sheets S, a feed roller 11 for feeding out the sheets S stored in the sheet cassette 10, and a sheet fed by the feed rollers 11. And a separation pad 12 for separating the separated sheets S one by one. The sheets S stored in the sheet cassette 10 are conveyed while being separated one by one by the cooperation of the feeding roller 11 and the separation pad 12. The paper is fed toward the passage R. In addition, a first feeding unit is configured by the feeding roller 11 and the separation pad 12.

On the other hand, the multi-feeding device B, which is a sheet feeding device, includes a stacking tray 13 which is a sheet storage section for storing sheets, a feeding roller 15 for feeding out the sheets S stacked on the stacking tray 13, and A separation pad 16 for separating the sheets fed by the feed roller 15 one by one
The sheets stacked on the stacking tray 13 are fed toward the transport path R while being separated one by one by the cooperation of the feed roller 15 and the separation pad 16. . The feeding roller 15 and the separation pad 16 constitute a second feeding unit.

In FIG. 1, reference numeral 14 denotes a motor provided as a driving means for driving the feeding roller 15 provided in the multi-feeding device B. Reference numeral 18 denotes a feed path provided between the stacking tray 13 and the transport path R. Sheets S from the multi-feeding device B are sent out to the transport path R while being guided by the feed path 18. It has become.

In this embodiment, the feeding passage 18 is formed on the upper surface of the end of the sheet cassette 10 on the side of the multi-feeding device, and feeds a sheet S such as thick and hard cardboard or an envelope. Even when the sheet S is fed, the sheet S has a curvature large enough to reduce the resistance due to the bending of the sheet S and to feed the sheet S stably.

Next, the printer 40 constructed as described above
Will be described.

At the time of image formation, first, the surface of the photosensitive drum 4 rotating in the direction of the arrow is uniformly charged, and thereafter, the charged drum surface is irradiated with laser light according to image information by the optical system 5. The surface of the drum is exposed to form a latent image, and the latent image is developed into a visible image by developing with a developing unit 6.

Next, the visualized toner image is fed from the cassette sheet feeding device A to a substantially vertical conveyance path R by applying a bias to the transfer roller 7, or the multi-feeding is performed. Feeding path 1 having a curvature from feeding device B
After being sent out to the conveyance path R via the transfer roller 8, the image is transferred onto the sheet S conveyed by the conveyance roller 1. After the transfer of the toner image, the sheet S is conveyed to the fixing unit 8, and the toner image is heated and fixed by the fixing unit 8. The paper is discharged to the paper unit 42.

In the present embodiment, the sheet cassette 10 can be pulled out in the feeding direction as shown by the arrow in FIG. 2, and when storing the sheet S, it is shown in FIG. The sheet cassette 10 is pulled out from the main body as described above. Further, in the present embodiment, as described above, the feeding passage 18 is
Is formed on the upper surface of the end portion on the side of the multi-feeding device, so that the multi-feeding device B can feed the sheets S when the sheet cassette 10 is mounted.

On the other hand, the multi-feeding device B is rotatably held by the main body 41 by holding means (not shown), and is provided in the sheet cassette 10 as shown in FIG. The sheet feeding position (hereinafter, referred to as a first position) substantially horizontal to the sheet cassette 10 so that the sheet S can be sent out to the supplied feeding path 18, that is, the sheet feeding between the multi-feeding device B and the sheet cassette 10. The position is provided at a position that is substantially the same in the height direction.

When forming an image, the multi-feeding device B
Is located at the first position and has a large curvature in the feed passage 18.
When the sheet S is sent out, the resistance due to the bending of the sheet S is reduced even when the sheet S such as thick and hard cardboard or an envelope is fed, so that the sheet can be fed stably.

As described above, the sheet cassette 10 is provided with the feeding passage 18 having a large curvature, and the multi-feeding device B is located at the first position when forming an image, so that the height of the main body 41 is increased. Stable feeding of the sheet S can be performed without increasing the size, whereby the main body 41 can be downsized while securing stable feeding performance of the sheet S.

On the other hand, when the sheet cassette 10 is pulled out from the main body or when the multi-feeding device B is not used, the multi-feeding device B is rotated to pull out the sheet cassette 10 as shown in FIG. Is moved to a standing position (hereinafter referred to as a second state) which does not affect the position.

When the sheet cassette 10 is pulled out from the main body in this manner, the multi-feeding device B is rotated to the second position.
The sheet cassette 10 can be pulled out without being disturbed by the multi-feeding device B even when the sheet feeding position is set to a position substantially horizontal to the sheet cassette 10.

Next, a second embodiment of the present invention will be described.

FIG. 3 is an enlarged view of a sheet feeding section of the image forming apparatus according to the present embodiment. In the figure,
The same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

In the figure, reference numeral 31 denotes a motor provided as a driving means for driving a drive system (not shown) provided on a main body 41, and 32 denotes a first position and a second position of the multi-feeding device B as described above.
A rotation shaft 33 provided on the main body 41 so as to be rotatable with respect to the position is provided on the rotation shaft 32 and is driven by the motor 31 transmitted through a gear train 34 provided on the main body 41. This is an idler gear that is a drive transmission unit that rotates by means of a gear.

When the multi-feeding device B is at the first position as shown in FIG. 4, the idler gear 33 meshes with a gear 15a provided coaxially with the feeding roller 15 of the multi-feeding device B. Thus, the feed roller 15 rotates.

As described above, the driving means of the multi-feeding device B is provided on the main body side, and the driving of the driving means is transmitted to the feeding roller 15 via the idler gear 33 so as to be shared with the driving means on the main body side. Thus, the size and weight and cost of the multi-feeding device B can be reduced.

In this embodiment, when the multi-feeding device B moves to the second position as shown in FIG.
For example, the engagement of predetermined gears of the gear train 34 is released by a transmission releasing means (not shown). Thus, the drive transmission to the idler gear 33 is cut off and the drive transmission to the feed roller 15 by the idler gear 33 is cut off, so that the feed roller 15 does not rotate excessively.

In the above description, the case where the attaching / detaching operation of the sheet cassette 10 and the rotating operation of the multi-feeding device B are performed separately has been described. However, the present invention is not limited to this. An interlocking mechanism that interlocks the turning operation of the multi-feeding device B in conjunction with the attaching / detaching operation may be provided. By linking the detaching operation of the sheet cassette 10 and the rotating operation of the multi-feeding device B, a series of operations can be simplified.

[0045]

As described above, by setting the sheet feeding position of the sheet feeding device to be substantially horizontal to the cassette as in the present invention, a feeding passage having a large curvature can be provided. In addition, the apparatus main body can be downsized while ensuring stable sheet feeding performance. In addition, when the cassette is attached or detached, the sheet feeding device can be moved to a position that does not hinder the attachment / detachment of the cassette. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a printer as an example of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a state when a sheet cassette is pulled out in the printer.

FIG. 3 is an enlarged view of a sheet feeding unit of an image forming apparatus according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a state when the multi-feeding device of the image forming apparatus is rotated upward.

FIG. 5 is a diagram illustrating a schematic configuration of a conventional image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conveyance roller 2 Conveyance path arrange | positioned substantially perpendicularly 3 Image forming part 8 Fixing means 10 Sheet cassette 11 Feeding roller 13 Loading tray 14 Motor 15 Feeding roller 18 Feeding path 31 Motor 32 Rotating shaft 33 Idler gear 40 Printer 41 Printer body A Cassette sheet feeding device B Multi-feeding device R Transport path S Sheet

Claims (10)

[Claims] 1. An image forming apparatus for forming an image on a sheet conveyed to an image forming unit, comprising: a cassette for accommodating the sheet and being removably mounted in an apparatus main body; A first feeding unit that feeds the sheets stored in the cassette; a sheet storage unit that stores the sheets; and a second feeding unit that feeds the sheets stored in the sheet storage unit. A sheet feeding device attached to a side of the apparatus main body on a cassette drawer side, wherein a sheet feeding position of the sheet feeding device and a sheet feeding position of the cassette are substantially the same in the height direction. Wherein the sheet feeding device is movable to a position which does not hinder the drawing of the cassette when the cassette is pulled out. 2. The sheet feeding device according to claim 1, wherein the first feeding unit feeds the sheet from a sheet feeding device side of the cassette, and the second feeding unit feeds the sheet from the cassette side of the sheet storage unit. The image forming apparatus according to claim 1, wherein: 3. The sheet feeding device is rotatably supported by the device main body, and can feed a sheet when the sheet storage portion is in a substantially horizontal state, and the sheet storage portion is in an upright state. 3. The image forming apparatus according to claim 1, wherein the cassette can be pulled out when rotated. 4. A transport path for transporting the sheet sent from the cassette and the sheet feeding device to the image forming unit, and guides the sheet fed from the sheet feeding device to the transport path. 3. The image forming apparatus according to claim 2, wherein a feeding passage is provided at an end of the cassette on the sheet feeding device side. 5. The image forming apparatus according to claim 1, further comprising a substantially vertically extending conveyance path for conveying the sheet sent from the cassette and the sheet feeding device, wherein the image forming unit is disposed in the substantially vertically extending conveyance path. The image forming apparatus according to claim 2, wherein: 6. The image forming apparatus according to claim 3, wherein a driving unit for driving a second feeding unit of the sheet feeding device is provided in the apparatus main body. 7. A gear train for transmitting a driving force from the drive means to the second feeding means, wherein one gear in the gear train is provided at a rotation fulcrum of the sheet feeding device. The image forming apparatus according to claim 6, wherein the image forming apparatus is arranged. 8. The sheet feeding device according to claim 8, wherein the driving device drives a second feeding device of the sheet feeding device and also drives a first feeding device provided in the device main body. The image forming apparatus according to claim 6. 9. The apparatus according to claim 1, wherein when the sheet feeding device is moved to a position where the sheet feeding device does not hinder the drawing of the cassette, the drive transmission from the driving unit to the first feeding unit is cut off. The image forming apparatus according to claim 6. 10. The sheet feeding device according to claim 1, wherein the sheet feeding device is moved to a position substantially horizontal to the cassette and to a position that does not hinder the attachment / detachment of the cassette in conjunction with the attachment / detachment operation of the cassette. Image forming device.