JP2003192152A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operability by varying the protrusion of a paper feed tray cover to cover a back portion of a paper feed tray backward of an image forming device body to the size of the paper sheets stored in the paper feed tray. <P>SOLUTION: An image forming device has a paper feed tray 6 comprising a tray front member 11 and a tray back member 12 which are supported in a freely accessible manner inside and outside the device body 1, connected to each other in a retractable manner, and capable of expanding the total length in the longitudinal direction according to the size of the paper sheets stored therein. The paper feed tray cover to close an upper opening of the tray back member protruded from at least a back side of the device body is provided in an advancing/retractable manner in the longitudinal direction. The paper feed tray cover is constantly urged forward by a tension spring supported by the device body side, and supported movably in the longitudinal direction in an interlocking manner with the tray back member by a guide rail provided in the device body. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a paper feed tray containing paper to be supplied to an image forming unit of an image forming apparatus such as a copying machine, a facsimile machine, a printer, etc. The present invention relates to an improvement of an image forming apparatus provided with a paper feed tray whose length is extendable.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine, a facsimile, a printer, etc., has an image forming section of an electrophotographic type or other type in a main body of the apparatus, a sheet feeding tray for accommodating sheets to be supplied to the image forming section, It is provided with a paper feed mechanism and the like that takes out the papers on the paper feed tray one by one and feeds them to the image forming unit. The paper feed tray and the paper feed mechanism form a paper feed device. The paper feed tray that constitutes the paper feed device is detachably mounted in the main body of the device, and the paper feed mechanism automatically takes out the paper one by one from the uppermost paper of the paper stack stored in the paper feed tray. A configuration is provided for sending to the image forming unit. While the image forming apparatus is downsized and the installation area is reduced, the paper size accommodated in the paper feed tray is large and small, and the size of the paper feed tray is determined according to the maximum usable paper size. As a result, the plane area of the paper feed tray becomes larger than the installation area of the apparatus body, and a part of the paper feed tray, for example, the rear portion thereof, protrudes from the rear surface of the apparatus body.
Therefore, in order to eliminate the problem that part of the paper feed tray always protrudes from the rear part of the main body of the device regardless of the size of paper used and increases the overall installation area, the paper feed tray is divided into front and rear parts. By connecting both parts elastically, the paper tray can be expanded and contracted according to the size of the paper to be stored, and in a user environment where only small size paper is used, the paper tray can be shortened for paper feeding. In many cases, a method of reducing the flat area of the tray is adopted. As described above, in the image forming apparatus in which the drawing direction of the paper feed tray with respect to the apparatus main body and the direction in which the paper feed mechanism feeds the paper stored in the paper feed tray toward the image forming unit are the same, In the state where the paper feed tray is completely installed in the opening in the front of the apparatus main body, a layout is often adopted in which the front of the paper feed tray and the front of the apparatus main body are flush with each other. In this case, if a large size paper that exceeds the front-back width of the device is stored in the extendable paper feed tray and attached to the device body, the front-back size of the paper feed tray is larger than the front-back size of the device body. Since it becomes large, the rear portion of the paper feed tray projects rearward from the rear surface of the apparatus main body.

Further, in order to prevent dust and the like from being attached to the paper stored in the rear portion of the paper feed tray protruding from the rear surface of the main body of the apparatus, a cover is often attached to the upper opening of the rear member of the paper feed tray. . As a form of mounting the paper feed tray cover, the paper feed tray cover is detachably fixed to the apparatus main body or the paper feed tray cover is directly detachably fixed to the paper feed tray. However,
In the former configuration where the paper feed tray cover is fixed to the main body of the device, the paper feed tray cover becomes large because it covers the paper inside with the rear part of the paper feed tray extended to the rear of the main body of the device. Even if the paper feed tray is contracted, only the paper feed tray cover is projected and the installation area becomes large, and the paper feed tray cover needs to be attached to the rear of the main body of the device. , It is inconvenient to remove it and work around the device body. Further, not only when a paper jam occurs in the paper feed tray, but also when a jam occurs in another conveyance path of the main body of the apparatus, the image forming operation and the paper conveyance operation are stopped. There is a case where the paper is sent out on the conveyance path from the tray to the image forming unit, and it is necessary to pull out the paper feed tray to remove the paper in such a case. If multiple operators perform this jam processing, when one operator removes the paper feed tray cover at the rear of the paper feed tray protruding to the rear of the main body of the device and has his or her hand inserted into the paper feed tray from above. If another operator tries to pull out the paper feed tray from the front side of the apparatus, a hand inserted by the operator located at the rear may be caught between the rear end of the paper feed tray and the apparatus body, resulting in injury. On the other hand, in the latter configuration in which the paper feed tray cover is directly fixed to the paper feed tray in a detachable manner, the paper feed tray cover needs to be removed every time paper is supplied to the paper feed tray, which causes a problem in operability.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and is a sheet feeding tray of a type that is configured to be extendable in the front-rear direction and has a rear portion protruding from the rear surface of the apparatus main body when expanded. The size of the paper tray for accommodating small-sized paper can be adjusted by changing the amount of projection of the paper tray cover that covers the rear of the paper tray to the rear of the main body according to the size of paper stored in the paper tray. If the paper feed tray cover is in the contracted state, the paper feed tray cover is retracted into the main body of the device to save space, and the paper feed tray cover can be automatically moved back and forth without the operator being aware of it. Accordingly, an image forming apparatus having improved operability is provided. In addition, the paper feed tray cover always covers the opening of the rear of the paper feed tray protruding from the rear surface of the main body of the paper feed tray, so that when one or more operators perform jam processing, one operator can open the paper feed tray. When pulling out, even if another operator unconsciously inserts his / her hand into the rear member of the paper feed tray from above, there is no risk of getting injured by pinching the hand between the rear member of the paper feed tray and the main body of the device. Therefore, the issue is to ensure safety.

[0005]

In order to solve the above-mentioned problems, the invention of claim 1 is directed to the inside and outside of the apparatus body from an image forming portion arranged in the apparatus body and an opening formed in the front surface of the apparatus body. A paper feed tray provided with a tray front member and a tray rear member that are supported so that they can be freely taken in and out, and that are connected to each other so that they can move toward and away from each other, and that have a total length in the front-rear direction that can expand and contract according to the size of the paper to be stored; A paper feed mechanism that takes out the paper on the paper tray to the front side in the drawing direction of the paper feed tray and supplies it to the image forming unit. In an image forming apparatus having a configuration in which it projects rearward from the rear surface, a paper feed tray cover that closes at least the upper opening of the tray rear member protruding from the rear surface of the apparatus main body is moved forward and backward. The feed tray cover is always urged forward by a tension spring supported by the main body of the apparatus, and can be moved in the front-rear direction in conjunction with the tray rear member by a guide rail provided in the main body of the apparatus. When the tray rear member is projected rearward of the apparatus main body, the paper feed tray cover is projected rearward in conjunction with the tray rear member, and when the tray rear member is moved forward. It is characterized in that it is retracted into the main body of the apparatus and the rearward protruding length is shortened. According to the present invention, there is provided a paper feed tray cover that can move in the front-back direction in conjunction with the operation of attaching and detaching the extendable paper feed tray to and from the apparatus main body, and can return to the inside of the apparatus main body by the restoring force of the spring and can be stored. As a result, it is possible to make the installation area compact when accommodating small-sized paper, and it is possible to provide excellent workability and safety during maintenance by eliminating the need to attach and detach the paper feed tray cover.

According to a second aspect of the present invention, the image forming section disposed in the apparatus main body and the image forming section disposed in the front surface of the apparatus main body are supported so as to be able to move in and out of the apparatus main body, and can be moved toward and away from each other. A paper feed tray including a tray front member and a tray rear member configured to extend and contract in the entire length in the front-rear direction according to the size of paper that is connected and accommodated, and the paper on the paper feed tray in the drawing direction of the paper feed tray. A sheet feeding mechanism that takes out the sheet to the image forming unit and supplies it to the image forming unit, and in a state where the length of the sheet feeding tray in the front-rear direction is enlarged, the rear end of the sheet is projected rearward from the rear surface of the apparatus body. In the apparatus, a paper feed tray cover for closing at least an upper opening of a tray rear member protruding from a rear surface of the apparatus main body is provided so as to be able to move forward and backward, and the paper feed tray cover is (1) When the rear member is projected rearward of the device main body, it is projected rearward in conjunction with the tray rear member, and when the tray rear member is moved forward, it is retracted into the main body of the device and the rearward protruding length is short. The paper feed tray cover is provided with a lock lever that is swingably supported and engages with and disengages from the apparatus main body. When the paper feed tray is not inside the apparatus main body, the lock lever is in the lock position. Hold the paper feed tray cover inside the main body of the device, and when the paper feed tray is inserted into the main body of the device, move the lock lever to the unlocked position so that the paper feed tray cover can be interlocked with the rear member of the tray. It is characterized by having done. According to the invention of claim 2, without using an elastic body such as a spring for returning the paper feed tray cover into the apparatus, the lock lever provided on the paper feed tray cover is interlocked with the operation of attaching and detaching the paper feed tray. Since the paper feed tray cover and the paper feed tray can be interlocked with each other by operating them, there is no fear of creep and the same effect as the invention of claim 1 can be obtained.

According to a third aspect of the present invention, in the second aspect, the lock lever is supported by the side surface of the paper feed tray cover so as to be swingable in the vertical direction, has a C-shaped arm at the rear portion, and has a front portion at the front portion. A lock piece is provided, and further, the lock piece is elastically biased in the locking direction to be locked in a locking hole provided in the apparatus main body by an elastic member. A lock pin for engaging with the C-shaped arm to move the paper feed tray cover backward or forward is provided, and when the paper feed tray is mounted in the main body of the apparatus, the lock pin is attached to the C-shaped arm. The lock piece is disengaged from the locking hole of the main body of the apparatus by swinging the lock lever as a whole in the unlocking direction against the elastic member while engaging the inside and pressing it backward.
When mounting the paper feed tray inside the main body of the device, the lock pin of the paper feed tray engages with the C-shaped arm of the lock lever to move the paper feed tray cover backward and rotate the lock lever in the unlocking direction. Since the tray cover is moved, it can be moved to the rear, and when pulling out the paper feed tray, the lock pin engages with the other part of the C-shaped arm and pulls it forward. The cover can be moved forward as a whole, and the lock lever is elastically biased in the locking direction. Can be locked to.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall schematic cross-sectional view of an example of an image forming apparatus according to a first embodiment of the present invention, in which a large-sized sheet P1 that exceeds the front-rear width of the apparatus body is accommodated in a paper feed tray. Indicates. FIG. 2 shows a state where the small size paper P2 is accommodated in the paper feed tray. Further, FIG. 3 is a cross-sectional view of the paper feed tray cover storage portion of the image forming apparatus as viewed from the rear. In FIG. 1, the image forming apparatus 1 includes an image forming section (photoreceptor, charging section, developing section, transfer section, etc.) 3 arranged in a main body 2 of the apparatus, a writing unit 4, and a fixing unit. The unit (image forming portion) 5, a paper feed tray 6 supported so as to be freely inserted into and removed from the inside and outside of the device main body from a front portion of an opening 2a formed through from the front surface to the rear surface of the device main body 2, and the paper feed tray 6
A sheet feeding mechanism 7 and the like for taking out the sheet P in the inside in the drawing direction of the sheet feeding tray and conveying it to the image forming unit 3 are provided.
The paper feed tray 6 includes a tray front member 11 and a tray rear member 12 which are connected to each other so as to be able to move toward and away from each other and are configured to be expandable / contractible in the entire length in the front-rear direction according to the size of the paper stored. Both tray members 11 and 12 have a front-back dimension of the paper feed tray 6 by the paper feed tray lock portion 13.
It is fixed in a predetermined positional relationship such that the size matches the size of the paper. That is, the paper feed tray 6 is configured to be extendable / contractible in the front-rear direction by the paper feed tray lock portion 13, and as shown in FIGS.
In the state in which is attached, only the tray rear member 12 changes the position in the front-rear direction while the tray front member 11 is fixed to the apparatus main body. In other words, the position of the front end surface of the paper feed tray 6 is always almost the same as the front surface of the apparatus main body, and only the tray rear member 12 projects into the rear portion of the apparatus according to the size of the sheets to be stored.

Inside the opening 2a of the apparatus main body 2, the paper feed tray cover 1 for closing at least the upper opening of the rear portion (tray rear member 12) of the paper feed tray 6 protruding from the rear surface of the apparatus main body.
5, the paper feed tray cover 15 is constantly urged forward by a tension spring 16 supported on the apparatus main body 2 side, and is linked to the tray rear member 12 by a guide rail 21 provided inside the apparatus main body. It is supported so that it can move in any direction. That is, one end of the tension spring 16 is supported by the locking portion 17 on the apparatus main body 2 side, and the other end is supported by the locking portion 18 provided on the paper feeding tray cover 15, so that the paper feeding tray cover 15 is fixed. It can always be urged forward. Therefore, when the tray rear member is projected rearward of the apparatus main body 2, the paper feed tray cover 15 is projected rearward in conjunction with the tray rear member, and when the tray rear member is retracted forward (inside the apparatus main body). Is configured such that the rearward protruding length of the paper feed tray cover is short. As described above, the paper feed tray cover rails 21 are provided on the left and right sides of the housing of the apparatus main body 2, and the paper feed tray cover 15 is supported by the guided portions 15a protruding from both sides by the rails 21 to move back and forth. You can move. When replenishing or replacing paper,
The entire paper feed tray 6 is taken out from the main body of the apparatus to perform the work. When the paper of different size is to be inserted, the length of the paper feed tray is expanded and accommodated according to the paper size, and then the paper is mounted in the main body of the apparatus. . When the paper feed tray 6 in which the tray front member 11 and the tray rear member 12 are connected by the paper feed tray lock portion 13 in a predetermined positional relationship according to the paper size is inserted into the opening 2a of the apparatus main body 2 from the front, The paper feed tray rear end projection 12a is located on the paper feed tray cover 1 in the middle of the apparatus body.
By hitting the inside of the rear end surface of the sheet 5 and further pushing the sheet feeding tray 6, the sheet feeding tray cover 15 is pushed out to the rear of the apparatus main body. The amount by which the paper feed tray cover 15 projects from the rear of the apparatus main body varies depending on the expansion / contraction state (length in the front-rear direction) of the paper feed tray. In this state, pulling out the paper feed tray 6 forward from the opening 2a of the apparatus main body,
The paper feed tray cover 15, which has been projected rearward until then, is returned to the front by the tension spring 16 and can be stored in the main body of the apparatus.

As shown in FIG. 1, the operator selects a large size paper P.
When 1 is accommodated, the paper feed tray 6 is expanded and used. Therefore, the amount of projection from the rear of the apparatus main body 2 increases, and the amount of projection of the paper feed tray cover 15 pushed out accordingly also increases. As shown in FIG. 2, when accommodating the small-sized paper P2, the paper feed tray 6 is contracted and used. Therefore, the amount of protrusion to the rear of the main body of the apparatus is small, and the protrusion of the paper feed tray cover 15 pushed out accordingly. The amount becomes smaller. Therefore, in a user environment in which only a small size paper P2 is used, the installation area of the image forming apparatus is small, and the installation area can be minimized according to the size of the paper used. Further, it is not necessary to attach and detach the paper feed tray cover 15 when the apparatus body is installed or moved, and workability can be improved. Also, the paper feed tray cover 1
5 always covers the rear opening of the paper feed tray protruding from the rear surface of the main body of the apparatus, so that when one operator pulls out the paper feed tray when another operator performs jam processing, another operator unconsciously reads the main body. Even if one inserts his / her hand into the paper feed tray that has popped out to the rear from above, there is no risk of accidentally pinching the hand, thereby ensuring safety.

Next, FIGS. 4 (a) and 4 (b) are side views of the essential parts showing the configuration of the lock lever portion (lock mechanism) provided in the image forming apparatus according to the second embodiment of the present invention, and from the rear side. It is sectional drawing of the lock lever part seen, and all have shown the locked state. 5A and 5B are diagrams showing the operation of the lock lever in the unlocked state. In this embodiment, a lock lever 25 swingably supported by the side surface of the paper feed tray cover 15 in the first embodiment is provided, and the lock lever 25 is shown when the paper feed tray 6 is not inside the apparatus main body. 4, the paper feed tray cover 15 is fixed in the main body of the apparatus while the paper feed tray 6 is inserted into the main body 2, and the lock lever 25 is moved to the unlocked position shown in FIG. Thus, the paper feed tray cover 15 can be interlocked with the tray rear member 12. Note that the tension spring 16 can be omitted in this embodiment. That is, by operating the lock lever 25 at the time of attaching / detaching the paper feed tray 6, it is possible to interlock the paper feed tray cover 15 without the tension spring 16 so that the paper feed tray cover 15 is projected rearward or moved forward. It will be possible. That is, the lock lever 25 provided on the side surface of the paper feed tray cover 15 and swingable includes a main body 27 swingably supported on the side surface of the cover 15 by a swing fulcrum 26.
Has a C-shaped arm 27a (the front side is open) integrated in its rear part and a lock piece 27b integrated in its front part. The lock lever 25 is constantly elastically biased in the counterclockwise direction (lock direction) by a torsion coil spring or the like (elastic member) not shown.

The open portion of the C-shaped arm 27a is opened obliquely downward to the right in the drawing, and the engaged portion 27a 'located at the upper end thereof projects slightly downward. Further, a lock pin 31 is provided on the outside of the side surface of the tray rear member 12 which constitutes the paper feed tray 6, and when the paper feed tray is mounted in the main body of the apparatus, the lock pin 31 is provided behind the lock pin 31 in the horizontal direction. Is located at the open portion of the C-arm 27a of the lock lever 25. When the lock pin 31 moves rearward, the lock pin 31 enters the concave inside of the C-shaped arm 27a and contacts the lower part inside the concave, so that the entire lock lever 25 moves in the clockwise direction (lock releasing direction). It acts to rotate. The engaged portion 27a 'is
It does not necessarily have to be a part of the C-shaped arm 27a, and may be a separate member protruding from the main body 27. Therefore,
Such a modified configuration also belongs to the technical scope of the present invention. As shown in FIG. 4A, the tray cover 1
When 5 is retracted and stored in the main body of the device,
A locking hole 22 is provided in the housing of the apparatus main body 2 facing the lock piece 27b of the lock lever 25, and the lock lever 25 biased counterclockwise around the fulcrum 26 by the spring is , The lock piece 27b is the locking hole 2
When it is in the positional relationship corresponding to No. 2, the tray cover 25 is fitted and locked in the locking hole to prevent the tray cover 25 from moving back and forth.

Next, when the paper feed tray 6 is inserted into the main body of the apparatus when the lock lever is in the state shown in FIG.
As shown in (a), the paper feed tray lock pins 31 provided on the left and right side surfaces of the paper feed tray enter into and engage with the lock lever C-shaped arm 27a, and when the paper feed tray 6 is further pushed, the lock pin 31 is C-shaped. Since the lower part inside the concave shape of the mold arm 27a is pressed further rearward, the lock lever 25 swings clockwise, the lock piece 27b is disengaged from the apparatus main body side locking hole 22 and the constraint is released, and the sheet is further fed. By pushing the tray 6 into the apparatus main body (rearward), the tray rear member 12 is projected rearward of the apparatus main body with the paper feed tray cover 15 being covered. On the contrary, when the paper feed tray 25 is pulled out from the front surface of the opening 2a of the apparatus main body, as shown in FIG.
As described above, since the paper feed tray lock pin 31 engages with a part (engaged portion) 27a 'of the lock lever C-shaped arm 27a and pushes it forward, the paper feed tray cover 15 interlocks with the front. Moved to and stored in the main body of the device. When pulling out the paper feed tray 6 further, this time the lock lever 2
5 swings counterclockwise and returns to the state of FIG. 4A, the lock piece 27b is fitted into the apparatus main body locking hole 22, and at the same time, the paper feed tray lock pin 31 is disengaged from the lock lever C-shaped arm 27a. The paper feed tray cover 15 is fixed to the main body of the apparatus, and the paper feed tray 6 is free and can be pulled out forward. Therefore, the tray cover can reliably follow the attachment / detachment operation of the paper feed tray, and it is possible to provide the paper feed device in which malfunction does not easily occur. In the above embodiment, the case where the attachment / detachment direction of the paper feed tray coincides with the front-back direction of the apparatus main body has been shown, but this is only an example, and the paper feed tray is attached / detached along the left / right direction of the apparatus main body. However, the present invention can be applied. Further, the system of the image forming unit is not limited to the electrophotographic system,
The present invention can be applied to a sheet feeding device of an image forming apparatus including an image forming unit (printing unit) of any type.

[0014]

As described above, according to the present invention, in the paper feed tray of the type in which the dimension in the front-rear direction can be expanded and contracted and the rear part is projected from the rear surface of the main body of the apparatus when expanded, the paper to be accommodated in the paper feed tray. When the size of the paper feed tray is reduced to accommodate small size paper by changing the protruding amount of the paper feed tray cover that covers the rear of the paper feed tray to the rear of the main body according to the size. In order to save space, the paper tray cover is retracted to the main unit side, and the operability is improved by automatically moving the paper tray cover back and forth without the operator being aware of it. be able to. Also,
The paper feed tray cover constantly covers the opening of the rear of the paper feed tray protruding from the rear surface of the main body of the paper feed tray,
When multiple operators perform jam processing and one operator pulls out the paper feed tray, even if other operators unintentionally insert their hands into the paper feed tray rear member from above, Safety can be secured by eliminating the risk of injury by pinching hands between the device and the device body. That is, according to the first aspect of the present invention, by installing the paper feed tray cover that moves in conjunction with the detachable operation of the extendable paper feed tray and can be stored in the main body of the apparatus, it is installed when storing small size paper. The area can be made compact, and excellent workability and safety at the time of maintenance can be provided by eliminating the need for attaching and detaching the paper feed tray cover. According to the second and third aspects of the present invention, since the lock lever can be provided and the feed tray cover and the feed tray can be interlocked with each other without directly using an elastic body such as a spring, there is a risk of creep. Therefore, the same effect as the invention according to claim 1 can be obtained.

[Brief description of drawings]

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

FIG. 2 is an overall sectional view of an image forming apparatus according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part of FIG. 1 or 2.

4A and 4B are a side view and a rear vertical sectional view showing a lock mechanism of an image forming apparatus according to another embodiment of the present invention.

5 (a) and 5 (b) are operation explanatory views of the lock mechanism.

[Explanation of symbols]

1 image forming apparatus, 2 apparatus body, 2a opening, 3
Image forming unit, 4 writing unit, 5 fixing unit, 6
Paper feed tray, 7 paper feed mechanism, 11 tray front member, 1
2 Tray rear member, 13 Paper feed tray lock part, 15
Paper feed tray cover, 16 tension spring, 21 guide rail, 22 locking hole, 25 lock lever, 26 swing fulcrum, 27 main body, 27a C-arm, 27b lock piece.

Claims (3)

[Claims] 1. An image forming unit disposed in the apparatus main body,
A tray front which is supported by an opening formed in the front surface of the apparatus main body so as to be able to move in and out of the apparatus main body, and which is connected to each other so as to be able to approach and separate from each other, and has a length in the front-rear direction which can be expanded and contracted in accordance with the size of a sheet to be stored. A sheet feeding tray including a member and a tray rear member; and a sheet feeding mechanism that takes out a sheet on the sheet feeding tray forward in a drawing direction of the sheet feeding tray and supplies the sheet to the image forming unit. In the image forming apparatus having a structure in which the rear end of the tray protrudes rearward from the rear surface of the apparatus body when the length in the front-rear direction of the apparatus is enlarged, the upper opening of the tray rear member protruding at least from the rear surface of the apparatus main body in the apparatus main body. A paper feed tray cover that closes the paper feed tray cover is provided so as to be able to move forward and backward, and the paper feed tray cover is always urged forward by a tension spring supported on the apparatus main body side, and It is supported by a guide rail provided in the main body of the tray so as to be movable in the front-rear direction in conjunction with the rear member of the tray. An image forming apparatus characterized in that it projects rearward in association with a member, and when the tray rear member is moved forward, it is retracted into the main body of the apparatus to shorten the rearward projection length. 2. An image forming unit disposed in the main body of the apparatus,
A tray front which is supported by an opening formed in the front surface of the apparatus main body so as to be able to move in and out of the apparatus main body, and which is connected to each other so as to be able to approach and separate from each other, and has a length in the front-rear direction which can be expanded and contracted in accordance with the size of a sheet to be stored. A sheet feeding tray including a member and a tray rear member; and a sheet feeding mechanism that takes out a sheet on the sheet feeding tray forward in a drawing direction of the sheet feeding tray and supplies the sheet to the image forming unit. In the image forming apparatus having a structure in which the rear end of the tray protrudes rearward from the rear surface of the apparatus body when the length in the front-rear direction of the apparatus is enlarged, the upper opening of the tray rear member protruding at least from the rear surface of the apparatus main body in the apparatus main body. A paper feed tray cover for closing the tray is provided so as to be able to move forward and backward, and the paper feed tray cover is interlocked with the tray rear member when the tray rear member is projected rearward of the apparatus main body. When the rear member of the tray is moved forward, it is retracted into the main body of the apparatus to shorten the rearward projection length, and the main body of the apparatus is swingably supported by the paper feed tray cover. A lock lever for engaging and disengaging with respect to is provided, and when the paper feed tray is not inside the apparatus main body, the lock lever is held at the lock position to fix the paper feed tray cover inside the apparatus main body.
An image forming apparatus characterized in that, when the paper feed tray is inserted into the apparatus main body, the lock lever is moved to an unlocked position so that the paper feed tray cover can be interlocked with a tray rear member. 3. The lock lever is swingably supported in a vertical direction by a side surface of the paper feed tray cover, has a C-shaped arm at a rear portion and has a lock piece at a front portion, and is further locked by an elastic member. The piece is constantly elastically biased in a locking direction to be locked in a locking hole provided in the main body of the apparatus, and the side surface of the paper feed tray is engaged with the C-shaped arm when being attached to and detached from the main body of the apparatus. A lock pin for moving the paper feed tray cover backward or forward is provided. When the paper feed tray is mounted in the main body of the apparatus, the lock pin engages with the C-shaped arm to move it backward. The image forming apparatus according to claim 2, wherein the entire lock lever is swung in the unlocking direction against the elastic member while being pressed to disengage the lock piece from the locking hole of the apparatus body.