JPH07133050A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device which can use a paper discharge tray for auxiliary use in correspondence with the paper sheet size, maintaining the compactness of the device and keeping the excellent operation performance. CONSTITUTION:A paper discharge tray 6 is constituted as a part of the upper surface of a device body M without protruding to the side part from the device body M, and has the dimension permitting the mounting of a paper sheet having a standard size free from the bulging outside the device. Further, a paper discharge tray (auxiliary tray) 20 for auxiliary use which turns in the directions of arrows D1 and D2, in interlocking with the mounting and demunting for the device body M of a paper feeding cassette 1' corresponding to the paper sheet P' having the longer size than the standard size is installed. When the paper feeding cassette 1' is mounted in the direction of arrow A, the auxiliary tray 20 protrudes from the device body M and shifts to the first position (position shown by the full line) as the extension of the paper discharge tray 6, while when the paper feeding cassette 1' is demounted from the direction of arorw B, the auxiliary tray 20 is retreated from the first position, and shifts to the second position (position shown by the alternate long and two short dashes line for the accommodation in the state free from the bulging-out from the device body M.

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 printer, a copying machine and a facsimile, and more specifically, an auxiliary sheet discharge used for a sheet having a size larger than a reference size. The present invention relates to an image forming apparatus including a tray.

[0002]

2. Description of the Related Art FIG. 6 is an overall view of a conventional image forming apparatus (herein, a printer is shown as an example) adopting an electrophotographic method. This apparatus is roughly detachable (attached in the direction of arrow A) to a main body M of a sheet feed cassette 1 for loading and storing sheets P of a predetermined size, and a sheet feed roll for sequentially feeding the loaded sheets one by one. 2. An image forming unit 3 that forms a toner image based on image information on a fed sheet.
(Photosensitive drum 3a, charger 3b, optical writing head 3
c, developing device 3d, transfer device 3e, cleaner 3f, etc.), fixing device 4 for fixing the toner image on the paper, discharge roll 5 for discharging the fixed paper to the outside of the apparatus, stacking and storing the discharged paper A paper discharge tray 6 and the like are provided.

Here, there are several standard sizes of paper to be used, but the maximum size (maximum use size) that can normally be used is determined as a standard size due to the design of the main body of the device, and the standard size is smaller than that. The ones of this size can be used. The above-mentioned device is designed especially for the purpose of constructing the whole device in a small size and at a low cost. As is generally widely used, a part of the upper surface of the device main body M is used as a paper discharge tray 6, and the paper discharge tray 6 is used. Reference numeral 6 is set to a size in which sheets of the standard size (maximum use size) can be just stacked. That is, for example, when the A4 size is the reference size, the length d ′ of the paper discharge tray 6 is set so as to be substantially equal to the paper length d (d≈d ′).

Further, as the structure of the sheet feeding section on the main body side of the apparatus, it has been very general that the sheet is fed from the back side in the mounting direction of the sheet feeding cassette, but in recent years, as shown in FIG. A type in which paper is fed from the front of the paper cassette 1 in the mounting direction (direction of arrow A) has been proposed. By doing so, the vicinity of the paper feed roll 2 is largely opened only by removing the paper feed cassette 1, and thus when a paper jam occurs at the paper feed roll 2, the processing for removing the jammed paper is easy. There are some advantages. Further, since the paper feed cassette 1 can be attached / detached from the front surface (right side in the figure) of the apparatus main body M, operability is good, and moreover, the front surface of the paper feed cassette 1 with the paper feed cassette 1 attached to the apparatus main body M is provided. Since it is flush with the front surface of the apparatus main body M, the apparatus is very compact.

By the way, for example, A4 size (A4 size (210 mm x 297 mm) for domestic specifications, but letter size (216 mm x 279 mm) which is relatively the same size as A4 size for US specifications)
It is desirable that even a very compact device designed as a standard size can be used with a paper size longer than the A4 size such as a legal size (216 mm × 356 mm). However, predesigning the entire device for legal size leads to an increase in size of the device.
Therefore, in order to allow the apparatus main body to have a compact design based on the letter size and also to use large size paper such as legal size, as shown in FIG. Is provided, and paper feed cassettes 1 ′, 1 ″ (indicated by a chain double-dashed line) of legal size or the like, which are longer than the A4 size paper feed cassette 1, are provided by L ₁ and L _{2 corresponding} to the length.
It has been proposed that the sheet can be fed by mounting the sheet in a state of being projected rearward from the opening 7.

However, since the length d'of the discharge tray 6 is set to be substantially equal to the length d of the standard size sheet P as described above, the size P of the sheet P longer than the standard size is set as described above. In the case of using ′ and P ″, the leading end portions of the papers P ′ and P ″ discharged onto the paper discharge tray 6 are longer than the reference size by L ₁ and L _{2 and} are protruded from the paper discharge tray 6 without scrambling. It may be stored in and fall in extreme cases. Therefore, as shown in FIG. 6, an auxiliary sheet discharge tray (auxiliary tray) 8 is prepared as an option, and the sheet mounting surface of the auxiliary tray 8 is an extension of the sheet arrangement surface of the sheet discharge tray 6. It could be attached to the apparatus main body M.

As described above, the paper feed cassette 1 ',
When 1 ″ is mounted so as to project from the opening 7 toward the rear of the apparatus, there are problems that the paper stored in the projected portion absorbs moisture and is easily soiled with dust. It has been proposed to provide covers 11, 12 as shown in FIG. 7 to cover the exposed top surface of the 1 ″. Here, the cover 11 of FIG. 7A is a rotatable cover rotatably supported by the shaft 11a at the upper edge of the opening 7, and when the standard size sheet feeding cassette 1 is used, Although it is in a position to cover the opening 7 as shown by the solid line in the figure, when a paper feed cassette 1'having a size larger than the reference size is used, the rear end of the paper feed cassette 1'moves while protruding rearward from the opening 7 when it is mounted. According to
Finally, as shown by a chain double-dashed line, the sheet cassette 1'is moved to a position where it covers the upper surface of the exposed portion. Further, the cover 12 of FIG. 7B is slidable along the predetermined guide path from the inside of the apparatus main body to the outside through the opening 7, and the tension spring 1
2a is a sliding type cover configured to always receive an urging force toward the inside of the main body of the apparatus, and when the standard size sheet feeding cassette 1 is used, as shown by the solid line in FIG. When the paper cassette 1'stored in the apparatus and covering the opening 7 is used, and the size of the paper cassette 1'is longer than the reference size, the rear end of the paper cassette 1'projects rearward from the opening 7 and moves rearward. Move to
Finally, as shown by a chain double-dashed line, the sheet cassette 1'is moved to a position where it covers the upper surface of the exposed portion.

[0008]

The auxiliary tray 8 as shown in FIG. 6 is attached for the purpose of assisting the discharge tray 6 of the apparatus main body only when using a specific size paper longer than the reference size. Therefore, it is completely unnecessary when the paper of the sufficient size or smaller is used in the paper discharge tray 6 of the apparatus body. When the auxiliary tray 8 is not required in this way, it is easy to lose it because there is no particular place to store it. The advantages of doing so have diminished and are very disturbing.

Further, if the auxiliary tray 8 is an optional type which can be detached as in the above-mentioned conventional example, it is easy to forget to attach the auxiliary tray 8 to the main body of the apparatus when using a paper of a size longer than the standard size. If a long size sheet is ejected in the state of forgetting to attach the sheet, the sheet may fall out of the apparatus and the printed page order may be out of order. Even if the occurrence of such a problem can be avoided, the operability is extremely poor because the user is left to attach and detach the auxiliary tray 8.

A tray (original tray, paper ejection tray) which is basically projected from the side of the apparatus is moved back and forth according to the paper size used (that is, the paper size and the document size are detected and the tray is driven by a motor or the like). To move)
Is disclosed in Japanese Utility Model Publication No. 46-31471 and Japanese Patent Application Laid-Open No. 57-77159. However, if the tray driving motor and the control means therefor are provided to the compact device aiming at downsizing and cost reduction as described above, the device becomes extremely complicated and expensive against the intended purpose. This is not preferable because the original advantages of such a device are lost.

In view of the above conventional problems, the present invention is an image forming apparatus capable of using an auxiliary discharge tray according to a sheet size while maintaining the compactness of the apparatus and having good operability. The purpose is to provide.

[0012]

In order to achieve the above object, the present invention provides a sheet of a size which is provided on the upper part of the apparatus body without protruding from the apparatus body, is discharged from the apparatus body and does not protrude from the apparatus body. And a paper feed cassette for accommodating paper that is sized to protrude outside the apparatus main body when the paper is loaded on the paper ejection tray, and is removable from the apparatus main body to introduce the paper into the apparatus main body. An image forming apparatus comprising: an operation unit that operates in response to attachment / detachment of the paper feed cassette to / from the apparatus main body; and the paper feed cassette attached to the apparatus main body in association with the operation unit. For stacking sheets that have overflowed from the sheet ejection tray when the first sheet is ejected
An auxiliary tray that moves to a position and moves to a second position that retracts from the first position when the paper feed cassette is detached from the apparatus main body.

[0013]

In the present invention, the auxiliary tray automatically moves to the first position and the second position in association with the attachment / detachment operation of the paper feed cassette. In other words, when a paper cassette that supports paper of a size longer than the standard size (size that protrudes outside the device body when it is loaded on the paper ejection tray at the top of the device body) is attached to the device body, it is linked to the loading operation. do it,
When the auxiliary tray moves to the first position, which is the position where the sheets protruding from the paper ejection tray can be stacked, and when the above-mentioned paper feed cassette is detached from the main body of the apparatus, the auxiliary tray is interlocked with the detaching operation. Moves to the second position, which is the position retracted from the first position.

When the paper cassette corresponding to the paper of the standard size or smaller is attached or detached, the interlocking operation as described above is not performed, and the auxiliary tray remains retracted to the second position.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view of the image forming apparatus of the first embodiment of the present invention, and FIG. 2 is an external perspective view of the image forming apparatus showing various states according to the insertion position of the paper feed cassette. The same members as those shown in are indicated by the same reference numerals.

The image forming apparatus of this embodiment is generally detachable from the apparatus main body M (attached in the direction of arrow A and detached in the direction of arrow B) and longer than the reference size (when A4 size is used as the reference size). Is, for example, legal size paper P '
A sheet feeding cassette 1'for stacking and storing sheets, a sheet feeding roll 2 for sequentially feeding the stacked sheets one by one, and an image forming unit 3 for forming a toner image based on image information on the fed sheets (photosensitive sheet). Body drum 3a, charging device 3b, optical writing head 3c, developing device 3d, transfer device 3e, cleaner 3f, etc.), fixing device 4 for fixing the toner image on paper, discharge of fixed paper to the outside of the apparatus It has a paper roll 5, a paper ejection tray 6 for accommodating the ejected paper, and the like, and the configuration up to this point is the same as that shown in FIG. Here, in particular, since the device on which the present invention is based is intended to configure the entire device in a small size and at a low cost, the paper discharge tray 6 does not project laterally from the device body M and the device body M does not project laterally.
Is configured as a part of the upper surface of the sheet, and is set to a size that allows sheets of standard size such as A4 size to be stacked exactly without protruding to the outside of the apparatus. For the same purpose as described above, the rear portion of the apparatus main body M can be used so that the apparatus main body M can be kept compact and a sheet feeding cassette 1'corresponding to a sheet of a size larger than the reference size can be used. An opening 7 is provided in the opening, and the rear end portion of the sheet feeding cassette 1'can be mounted through the opening 7 in a state of protruding toward the rear of the apparatus.

Further, in the present embodiment, an auxiliary discharge tray (auxiliary) which rotates in conjunction with the attachment / detachment of the paper feed cassette 1'corresponding to the paper of a size longer than the reference size to / from the main body M of the apparatus. The tray) 20 is provided. The auxiliary tray 20 is in the discharging direction (arrow C) the distal end portion of the apparatus main body front side of the M discharge tray 6 a (right side in FIG. 1), the arrow D _1, D ₂ direction by the rotation shaft 20a 1 is rotatably supported, and its rotation range protrudes from the apparatus main body M to the front side as shown by the solid line in FIG. Forming a first position (Fig. 2
2) (the position shown in FIG. 2A), which is retracted from the first position as shown by the chain double-dashed line in FIG. Up to). The auxiliary tray 20 is stored at the second position when the paper feed tray 1'is not used, and when the paper feed tray 1'is mounted in the apparatus main body M in the direction of arrow A, the auxiliary tray 20 is moved from the second position to the arrow position. When the paper feed tray 1 ′ is rotated in the direction D ₁ to the first position and the paper feed tray 1 ′ is removed from the inside of the apparatus main body M in the direction of arrow B, it is rotated from the first position in the direction of arrow D ₂ to the second position. The apparatus main body M is provided with an interlocking mechanism as an operating means for rotating the auxiliary tray 20 in association with the attachment / detachment operation of the sheet feeding cassette 1 '.

An example of the interlocking mechanism is shown in FIG. This interlocking mechanism is provided in the rack 21 on a part of the side surface of the paper feed cassette 1 '.
And a gear 22 that constitutes a rack and pinion mechanism by meshing with the rack 21 when the paper feed cassette 1'is attached or detached.
Of the auxiliary tray 20 and a plurality of gears 23 to 29 for transmitting the rotation to the rotation shaft 20a of the auxiliary tray 20. Here, the gear 23 is a bevel gear that rotates together with the gear 22 coaxially, and the gear 24 is a bevel gear that rotates together with the gear 25 coaxially. By meshing the gears 23 and 24 in a substantially orthogonal state, , The rotation direction of the gear 22 is converted and transmitted to the gear 25. The gear 29 located at the final stage is connected to the rotating shaft 20a of the auxiliary tray 20, and the rotation of the gear 29 is the rotation operation of the auxiliary tray 20 as it is.

In the above construction, when the paper feed cassette 1'is inserted into the apparatus main body M in the direction of arrow A, the rack 21 of the paper feed cassette 1'engages with the gear 22 during the insertion, and the gear 22 is moved. The rotation starts in the direction of arrow E. Then, the rotation is transmitted to the rotation shaft 20a via the gears 23 to 29, and the auxiliary tray 20 stored in the second position until then is rotated in the direction of the arrow D ₁ as shown in FIG. 2A. Begin to. Then, when the paper feed cassette 1'is finally completely installed in the regular position, the auxiliary tray 20 stands still in the first position as shown in FIG. Form the table surface. Therefore, when the paper P'in the paper feed cassette 1'is fed in this state and ejected onto the paper ejection tray 6 through a predetermined image forming process, the front end of the ejected paper P'is Although it largely protrudes from the discharge tray 6, the above-mentioned protruding portion is placed on the auxiliary tray 20 because the auxiliary tray 20 is at the first position as described above. In this way, even when the paper P ′ that is long enough to protrude from the paper discharge tray 6 is selectively used, the discharged paper does not drop out of the apparatus and the paper discharge tray 6 and It is reliably stacked and stored on the auxiliary tray 20.

On the other hand, when the paper feed cassette 1'has been used and the paper feed cassette 1'is removed from the apparatus main body M in the direction of arrow B, the gear 22 meshes with the rack 21 of the paper feed cassette 1'and the arrow Since it rotates in the F direction, its rotation is the gear 2
The auxiliary tray 20 that has been in the first position until then is rotated in the direction of the arrow D ₂ by being transmitted to the rotation shaft 20a via 3-29. Then, when the rack 21 and the gear 22 are disengaged from each other, the auxiliary tray 20 is set in the second position.

It should be noted that a rack 21 as shown in FIG. 3 is not provided in the paper feed cassette corresponding to the paper of the standard size or smaller that does not protrude from the paper discharge tray 6, and therefore, when the rack 21 is attached or detached, the above-mentioned rack 21 is used. The interlocking mechanism does not operate, and the auxiliary tray 20 remains stored in the second position.

Therefore, according to this embodiment, as described above, the auxiliary tray 20 is interlocked with the attachment / detachment operation of the sheet feeding cassette 1 '.
The auxiliary tray 20 moves to the first position protruding from the apparatus main body M only when the paper P ′ having a size longer than the reference size is used, and the paper P ′ having the long size is rotated. It is possible to prevent the falling, and when using the paper of a size not larger than the reference size in the paper discharge tray 6, the auxiliary tray 20 is kept in the second position where it does not protrude from the apparatus main body M, so that the entire apparatus is compact. The auxiliary tray 20 does not get in the way.
Since the user does not need to attach or remove the auxiliary tray 20 in this manner, the problem of forgetting to attach the auxiliary tray 20 can be avoided and extremely excellent operability can be obtained as compared with the conventional option type.

Further, the auxiliary tray 20 and the paper feed cassette 1 '
As shown in FIG. 3, the interlocking mechanism provided between and has a very simple structure consisting of only a plurality of gears. Therefore, the above-mentioned Japanese Utility Model Publication No. 46-31471 and Japanese Patent Publication No. 57-77159 are disclosed. Compared with the one which detects the paper size and the document size and moves the tray by motor drive etc. as disclosed in etc., the device can be configured very easily and cheaply, and the intended purpose (small size, low cost) A device according to can be realized.

The interlocking mechanism employed in the above embodiment is only an example, and the auxiliary tray is moved in association with the attachment / detachment of the paper feed cassette 1'to substantially extend the paper loading surface of the paper ejection tray 6. Various configurations can be adopted as long as they have the configuration described above. The schematic configurations of the second and third embodiments of the present invention including the interlocking mechanism of such another configuration are shown in FIGS. 4 and 5, respectively. Show.

In the second embodiment shown in FIG. 4, a cover 30 having the same structure as the rotatable cover 11 shown in FIG. 7A is provided, and the auxiliary tray 20 is operated in conjunction with the movement of the cover 30. It is configured to rotate. That is, the rotation shaft 30a of the cover 30 is connected to the gear 31, the rotation shaft 20a of the auxiliary tray 20 is connected to the gear 32, and the gear 33 meshing with the gear 32 and the chain 34 are bridged. It was done. Even in such a configuration, when the paper feed cassette 1'is mounted, the cover 30 is pushed away to move to a position (position shown by a solid line in FIG. 4) covering the upper surface of the exposed portion of the paper feed cassette 1 '. Gear 31, chain 34, gear 33 and gear 3 are interlocked with each other.
The auxiliary tray 20 is moved to the first position, which is an extension of the paper discharge tray 6, via 2. On the other hand, when the paper feed cassette 1'is detached, the cover 30 moves to the position that covers the opening 7 (the position shown by the broken line in FIG. 4).
0 moves to the second position retracted from the first position. Therefore, according to this embodiment, the same effect as that of the first embodiment can be obtained.

In the third embodiment shown in FIG. 5, instead of the rotary type auxiliary tray 20, a first position (position shown by a solid line) protruding from the apparatus main body M and a first position accommodated in the apparatus main body M are shown. Two
A slide type auxiliary tray 20 'is provided which can slide between a position (a position indicated by a chain double-dashed line) and a cover 40 having the same structure as the slide type cover 12 shown in FIG. 7B. The auxiliary tray 20 'is configured to slide in association with the movement of the. That is, the racks 41 and 42 are formed on the respective side portions of the cover 40 and the auxiliary tray 20 ', and
Gears 43 and 44 that form a rack and pinion mechanism by meshing with these gears are provided.
4 are connected by a chain 45. Even with this configuration, when the paper feed cassette 1'is mounted, the cover 40 moves to a position (position shown by a solid line in FIG. 5) covering the upper surface of the exposed portion of the paper feed cassette 1 ', so that the movement is interlocked with the movement. The auxiliary tray 20 'moves to the first position, while the cover 40 moves to the position (the position shown by the broken line in FIG. 5) stored in the apparatus main body M when the sheet cassette 1'is removed. In conjunction with this movement, the auxiliary tray 20 'moves to the second position retracted from the first position. Therefore, according to this embodiment, the same effect as that of the first and second embodiments can be obtained.

In the second and third embodiments, the transmission mechanism using gears and chains is adopted. Instead of this, a transmission mechanism using pulleys and belts or a transmission mechanism using gear trains as in the first embodiment is used. May be adopted. Of course, in the first embodiment, instead of the transmission mechanism by the gear train,
It is also possible to employ a transmission mechanism using gears and chains as in the second and third embodiments, a transmission mechanism using pulleys and belts, and the like. Further, in the first and second embodiments, instead of the rotary type auxiliary tray 20, the sliding type auxiliary tray 2 is used.
0'may be used, and also in the third embodiment, it is possible to use the rotary type auxiliary tray 20 instead of the sliding type auxiliary tray 20 '. As described above, various combinations of the transmission form of the interlocking mechanism and the movement form of the auxiliary tray are possible.

[0028]

According to the present invention, the auxiliary tray is moved in association with the attachment / detachment operation when attaching / detaching the paper feed cassette corresponding to the long size paper protruding to the outside of the apparatus body to / from the apparatus body. Therefore, the auxiliary tray can be moved to the first position protruding from the main body of the apparatus only when the auxiliary tray is needed (that is, when the above-mentioned long-sized paper is used) to prevent the above-mentioned long-sized paper from falling. On the other hand, when the auxiliary tray is not needed (that is, when using paper of a standard size or smaller), the auxiliary tray is stored in the second position where it does not protrude from the main body of the apparatus, so the compactness of the entire apparatus is not lost and the auxiliary The tray never gets in the way. Further, as compared with the conventional option type, since the attaching and detaching operations are completely unnecessary, the problem of forgetting to attach can be avoided and very excellent operability can be obtained.

[Brief description of drawings]

FIG. 1 is an overall view of an image forming apparatus according to a first embodiment of the present invention.

2A and 2B are external perspective views of the image forming apparatus according to the first embodiment, in which FIG. 2A shows a state in which a paper feed cassette 1'is inserted halfway, and FIG. 2B shows a normal state of the paper feed cassette 1 '. It shows the state where it is completely attached to the position.

FIG. 3 is a perspective view showing an example of an interlocking mechanism for rotating the auxiliary tray 20 in association with the attachment / detachment operation of the paper feed cassette 1 ′.

FIG. 4 is a schematic diagram of an image forming apparatus according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram of an image forming apparatus according to a third exemplary embodiment of the present invention.

FIG. 6 is an overall view of a conventional image forming apparatus.

7A and 7B are cross-sectional views of a cover provided to cover an exposed upper surface of a paper feed cassette and its vicinity, FIG. 7A shows a rotary type cover, and FIG. The thing which provided the cover of is shown.

[Explanation of symbols]

 1, 1 ', 1 "Paper feed cassette 2 Paper feed roll 3 Image forming unit 4 Fixing device 6 Paper discharge tray 7 Opening 20, 20' Auxiliary tray 20a Rotating shaft 21 Rack 22-29 Gear 30 Cover 31, 32, 33 Gear 34 Chain 40 Cover 41, 42 Rack 43, 44 Gear 45 Chain

Claims (1)

[Claims] 1. A paper ejection tray, which is provided on an upper part of the device main body without protruding from the main body of the device, and on which paper of a size that is discharged from the inside of the main body of the device and does not protrude from the main body of the device is stacked; An image forming apparatus, comprising: a paper feed cassette detachably attached to the apparatus main body for accommodating a paper of a size protruding outside the apparatus main body when introducing the paper into the apparatus main body. And an operating unit that operates in response to attachment / detachment of the sheet to / from the apparatus main body, and, in conjunction with the operating unit, stacks the sheets that have run off the paper discharge tray when the paper feed cassette is attached to the apparatus main body. An image forming apparatus, comprising: an auxiliary tray that moves to a first position and moves to a second position that retracts from the first position when the paper feed cassette is detached from the apparatus main body.