JP2002268505A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of an impact at the time of closing a cover for opening and closing an opening for work provided on an image formation device main body and to prevent the generation of a failure due to the influence of the impact in an image forming device. SOLUTION: This image forming device is provided with an image forming device main body 1, which is provided with a process unit 11 and a carrying route 12 in the inside and in which the opening 2 facing the carrying route is formed, the cover 3, which is provided so as to be turned between a closing position A for closing the opening and an opening position B on the outer side of the image forming device main body for opening the opening and pivoted to the image forming device main body and in which a component constituting the carrying route is attached to an inner surface, and a lever 31 and a hydraulic braking mechanism (cover operating means), which are provided on the image forming device main body and applies resistance force for suppressing turning to the closing position to the cover at the prescribed position of the process of turning the cover from the opening position to the closing position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art As an image forming apparatus used in a copying machine, a printer or a facsimile machine, an image forming mechanism provided on the side wall of the image forming apparatus main body, specifically, a photosensitive drum or the like is provided. A process unit having a developing unit, etc., and a work opening facing the transport path for transporting the recording paper so as to pass through the image forming mechanism are provided, and a cover for opening and closing this opening is turned around the image forming apparatus main body. It is provided movably, the cover is always closed with the cover, and when the paper jam occurs in the transport path using the opening to remove the jammed recording paper, or when inserting and removing it to replace the process unit In some cases, the cover is rotated to the open position to open the working opening and perform the work. In this image forming apparatus, since the opening faces the process unit and the transport path, a part (for example, a transfer device) forming a part of the image forming mechanism and a part of the transport path are formed on the inner surface of the cover. Parts (for example, a transport guide) are attached.

In this image forming apparatus, when the cover is closed and the cover collides with the main body of the image forming apparatus, an impact is generated. If the impact is left as it is, a part of the image forming mechanism provided on the cover (part of the image forming mechanism) For example, the transfer unit contacts the photosensitive drum of the process unit provided in the image forming apparatus main body, and the toner adheres thereto, and the toner comes into contact with the recording paper conveyed in the conveyance path to be soiled or attached to the cover. Inconveniences such as a displacement of a part (for example, a transport guide) constituting a part of the transport path and a change in the interval (width of the transport path) with respect to a transport guide provided in the image forming apparatus main body occur.

Therefore, in the conventional image forming apparatus, as a countermeasure against such an impact when the cover is closed, an elastic member for reducing the impact is attached to the image forming apparatus main body or the cover, or a simple shock absorber is provided. Has been done.

[0005]

In a conventional image forming apparatus, if an elastic member for cushioning impact is attached or a simple shock absorber is provided, the cover and the main body of the image forming apparatus may collide when the cover is closed. The impact caused by the impact is not enough to absorb the impact and suppress the occurrence of the above-mentioned inconvenience, and the various inconveniences mentioned above occur when the cover is closed. are doing.

An object of the present invention is to provide an image forming apparatus which suppresses generation of an impact when closing a cover for opening and closing a work opening provided in an image forming apparatus main body and prevents occurrence of a trouble due to the influence of the impact. With the goal.

[0007]

According to a first aspect of the present invention, there is provided an image forming apparatus including an image forming mechanism and a transport path for transporting recording paper so as to pass through the image forming mechanism.
And an image forming apparatus main body in which an opening facing the transport path is formed, and between a closed position for closing the opening and an open position outside the image forming apparatus main body for opening the opening. A cover pivotally supported by the image forming apparatus main body and having a component constituting the transport path attached to an inner surface thereof, and a cover provided on the image forming apparatus main body, wherein the cover rotates from an open position to a closed position. A cover operating means for applying a resistance to the cover at a predetermined position to prevent the cover from turning to the closed position.

According to the structure of the present invention, by applying a resistance force for suppressing the rotation of the cover from the position where the opening is opened to the position where the cover is closed to the position where the cover is closed, the image forming apparatus is gently moved by the cover. Closes the opening without contact with the main body without generating impact.

According to the configuration of the second aspect of the present invention, the first aspect is provided.
Wherein the predetermined position at which the resistive force is applied to the cover is a position close to the opening.

According to the configuration of the third aspect of the invention, the first aspect is provided.
The image forming apparatus according to any one of claims 1 to 3, wherein the cover has an opening-side distal end located downstream of the transport path with respect to a pivot base end.

According to the configuration of the invention of claim 4, according to claim 1,
In the image forming apparatus described in the above, the cover operating means applies a resistance force for suppressing the rotation of the cover from the closed position to the open position up to a predetermined position in the process of rotating the cover from the closed position to the open position. It is characterized by the following.

According to the structure of the invention of claim 5, according to claim 1,
5. The image forming apparatus according to claim 1, wherein the cover operating unit has a lever that rotates between the closed position and a predetermined position in a process of rotating the cover in the closed direction in conjunction with the rotation of the cover. Characterized in that:

According to the configuration of the invention of claim 6, according to claim 1,
5. The image forming apparatus according to claim 1, wherein the opening is for taking in and out the image forming mechanism.

According to a seventh aspect of the present invention, there is provided an image forming mechanism for recording an image on a recording sheet by being rotationally transmitted through a joint from a rotary driving mechanism and driven, and the image forming apparatus is arranged in the axial direction. An image forming apparatus main body having an opening for performing insertion and withdrawal in a direction perpendicular to the main body, and a cover provided in the image forming apparatus main body to open and close the opening,
Means for connecting the joint when the cover is closed in conjunction with the opening and closing operation of the cover and for connecting the joint when the cover is open. .

According to the configuration of the present invention, the operation of opening the lever and the operation of separating the process unit from the rotary drive mechanism can be performed simultaneously, which is very convenient.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view schematically showing an image forming apparatus. This image forming apparatus is a system in which a recording sheet is vertically conveyed from a lower side to an upper side to record an image.
In the figure, reference numeral 1 denotes an image forming apparatus main body, which is provided with a recording paper discharge section 6 in a middle section, and a rectangular opening 2 for work is formed in a vertical side face 1b. Further, the image forming apparatus main body 1 is provided with a cover 3 for opening and closing the opening 2. The cover 3 is formed in a rectangular shape large enough to close the opening 2, and as shown in FIGS. 3 to 5 (at the closing position A), the lower end edge is attached to the image forming apparatus main body 1 by a horizontal pivot 4. The pivot 4 rotates between a closed position A, which is pivotally supported and vertically closes the opening 3, and a horizontal open position B, which falls away from the closed position A to the outside of the image forming apparatus main body 1. It can move.

That is, as shown in FIGS. 2 to 4, the cover 3 has a pivot-side end located upstream (downward) in the recording paper transport direction in the closed position A. The opposite rotation-side end is located downstream (upper side) in the recording paper transport direction, and when the cover 3 is opened, the downstream side (upper side) in the recording paper transport direction.
Wide open from. This is because paper jam often occurs in the transport path 12 of the image forming apparatus main body 1 from the process unit 11 on the downstream side in the recording paper transport direction, and the cover 3 is widely opened from the downstream side (upper side) in the recording paper transport direction. This is because the paper on which the paper jam has occurred can be easily removed from the recording paper transport path 12.

FIG. 2 to FIG. 4 are cross-sectional views schematically showing the cover and its peripheral edge in the image forming apparatus. A process unit 11 is provided inside the image forming apparatus main body 1 and a transport path 12 for the recording paper P is formed. The process unit 11 is disposed so as to face the opening 2, and is horizontally movable through the opening 2 so as to be inserted into and removed from the image forming apparatus main body 1. The process unit 11 includes a photosensitive drum 13.
The photosensitive drum 13 and the developing device 14 are supported by a common frame to form a unit. The direction of the process unit 11 is set so that the rotation axis of the photosensitive drum 13 is parallel and horizontal to the side surface portion 1a of the image forming apparatus main body 1, and the rotation axis of the photosensitive drum 13 (axial direction of the process unit). To the image forming apparatus main body 1 through the opening 2 along a direction perpendicular to
It is designed to be extracted.

The process unit 11 receives rotation from a rotary drive (not shown) provided inside the image forming apparatus main body 1 via a joint which can be connected and separated and receives the rotation of the photosensitive drum 1.
3 is rotated. FIG. 5 is a perspective view schematically showing a unit for operating the cover 3 and a unit for operating the joint 23. In FIG. 5, reference numeral 21 denotes a unit-side rotation shaft, 22 denotes a body-side rotation shaft, and these are side surface portions 1a of the image forming apparatus main body 1.
Are arranged side by side on the same axis which is parallel and horizontal. Reference numeral 23 denotes a joint, which has a joint member 24 attached to the unit-side rotating shaft 21 and a joint member 25 attached to the main body-side rotating shaft 23. The joint member 24 and the joint member 25 are connected and separably connected. Have been. The joint 23 performs a connecting operation and a separating operation in response to an external drive command, and uses, for example, an electromagnetic clutch. That is, in the electromagnetic clutch, both joint members are connected and separated by a command from the drive circuit. The unit-side rotating shaft 21 is connected to the photosensitive drum 13 itself or the photosensitive drum 13 itself.

That is, in this image forming apparatus, the opening 2 of the main body 1 of the image forming apparatus has a front surface (paper surface of the recording paper) of the transport path 3 so that the recording paper P can be easily taken out from the transport path 3.
Therefore, the opening 2 is positioned parallel to the axial direction of the process unit 11 (the rotation axis direction of the photosensitive drum). Then, the process unit 11 moves along a direction perpendicular to the axial direction, passes through the opening 12, and puts into and out of the image forming apparatus main body 1. Conventionally, a mechanism is employed in which gears are combined to transmit rotation from a rotation drive mechanism provided in the image forming apparatus main body 1 to the process unit 11. That is, the gear can be engaged and disengaged by moving the process unit side gear shaft in parallel with the main body side gear shaft. But,
The rotation transmitting means combining the gears used to transmit the rotation of the rotation driving mechanism of the image forming apparatus main body 1 to the photosensitive drum 13 of the process unit 11 is limited in terms of rotational accuracy and the like in order to improve image quality. was there. For this reason, recently, a rotation transmitting means using a joint has been adopted. In other words, the rotation transmitting means using this joint is such that the process unit side shaft and the main body side shaft are located on the same axis, and the joint members provided on each shaft are connected and separably connected. The accuracy of rotation transmission is higher than the combination.

The process unit 11 is provided on the inner surface of the cover 3.
A transfer unit 15 is mounted in parallel with and opposed to the photosensitive drum 13. The transfer unit 15 records the toner image on the photosensitive drum 13 on a transfer roller 15 a that transfers the toner image on the recording paper P and the transfer roller 15 a. A pre-transfer roller 15 for bringing the recording paper P into contact with the photosensitive drum 13 on the upstream side in the paper transport direction
b is provided. A fixing device 16 is provided in the image forming apparatus main body 1 above the opening 2, and is provided with a recording paper P.
The recording paper P after fixing is discharged to the recording paper discharge section 2 of the image forming apparatus main body 1. The process unit 11 and the transfer unit 15
The fixing unit 16 forms an image forming mechanism.

In the main body 1 of the image forming apparatus, a paper feed roller 17 is provided below the opening 2 in parallel with the axial direction of the process unit 11, and a recording paper P made of cut paper is fed from a paper feed cassette (not shown). It is fed out and transported upward.

The conveyance path 12 conveys the recording paper P conveyed from the conveyance roller 17 from the lower side to the upper side to transfer the recording paper P from the photosensitive drum 13 of the process unit 11 to the transfer roller 1.
6 and a vertical path for conveying the fixing device 16 upward to the fixing device 16. The image forming apparatus main body 1 is provided with vertical guides 18 respectively over the upper side and the lower side of the process unit 11. On the inner surface of the cover 3, the upper side of the transfer unit 15 is opposed to the guides 18 on the image forming apparatus main body side. Vertical guides 19 are provided on the lower side, respectively, and these guides 18 and 19 are components constituting the transport path 12.

Next, means for operating the cover 3 and means for operating the joint 23 will be described with reference to FIG.

The cover operating means is such that the cover 3 is in the open position B
At a predetermined position C in the process of rotating from the closed position to the closed position A, and applies a resistance force to the cover 3 to suppress the rotation to the closed position A, and moves the cover 3 from the closed position A to the open position B. Opening position B to a predetermined position C in the process of turning toward
This is to apply a resistance force that suppresses turning to the side. here,
The predetermined position C is set at a position close to the opening 2, that is, the closing position A (a position deviating from the transport path 12). This is because the time required for the cover 3 to rotate from the open position B to the closed position A due to resistance is short, and the impact when closing the cover 3 can be suppressed without prolonging the operation time for closing the cover 3. .

As means for applying resistance to the cover 13, for example, a braking mechanism 4 is provided on a pivot 4 for pivotally supporting the lower end of the cover 3.
1 is provided, which applies resistance to the cover 3 via the pivot 4. The brake mechanism 41 is, for example, a hydraulic brake, and applies a brake when the cover 3 rotates between the closed position A and the predetermined position C.

In the image forming apparatus main body 1, levers 31 are provided on both sides in the width direction of the cover 13, respectively. The lever 31 is rotatably provided above the opening 2 in parallel with the pivot 4 and is provided inside the cover 2 when the cover 2 is closed.
And a second arm 35 which is located outside the cover 2 when the cover 2 is closed and projects radially downward from the lever shaft 32 when the cover 2 is closed. That is, the lever 31 rotates in a range corresponding to the closed position A and the predetermined position C in conjunction with the cover 3 while the cover 3 rotates between the closed position A and the predetermined position C. Here, levers 3 are provided on both sides of the cover 13 in the width direction.
The reason for providing 1 is to allow the cover 13 to rotate stably and to reach the closed position A and the open position B stably. Thereby, when the cover 31 is closed, the transfer device 16 and the guide 19 provided on the cover 31 can be accurately positioned. The configuration of the lever 31 is simple and effective as a member for operating the cover 3 described later.

In the main body 1 of the image forming apparatus, the lever 31 rotates in a range corresponding to the closing position A and the predetermined position C in conjunction with the rotation of the cover 3 between the closing position A and the predetermined position C. When closing, the lever 31 closes the closed position A and the predetermined position C.
Are provided with switches S1 and S2, respectively. That is, these switches S1 and S2 are connected to the braking mechanism 41 described above.
For controlling the operation of hydraulic equipment incorporated in the hydraulic circuit for driving the hydraulic circuit, and controlling the operation of the pressure oil in the hydraulic circuit by controlling the driving of the equipment to control how the braking mechanism 41 applies a resistance force to the cover 2. Is what you do. That is, resistance is applied when the cover 2 rotates between the closing position A and the predetermined position C in the opening direction and the closing direction. Each of the switches S1 and S2 is, for example, a limit switch, and is, for example, a member 31a provided on the lever shaft 3.
It is operated by

The image forming apparatus main body 1 has a switch S3 comprising, for example, a microswitch for outputting a signal for separating the joint 23 for transmitting the process unit rotation when the cover 3 is rotated from the closed position A in the opening direction. Is provided. The switch S3 is operated by a member 31b provided on a lever shaft 32 of the lever 31, for example.

The image forming apparatus main body 1 has a cover 3
An interlock switch S4 composed of, for example, a micro switch is provided to release the power of the entire image forming apparatus main body when the switch is opened. The switch S4 is operated by a member 4a provided on the pivot 4, for example.

To open the cover 3 in the closed position A shown in FIG. 2 in the image forming apparatus having the above-described configuration, the user opens the lever 31 by holding the second arm 31 by hand, for example. The first arm 33
Rotate in the same direction to come into contact with the inner surface of the cover 3 and push outward. Thereby, the cover 3 rotates together with the pivot 4 in the opening direction. Here, the member 31a of the lever 31
Are turned in the same direction, and first, the switch S in the open position A
When 1 is operated, the braking mechanism 41 operates to apply a resistance to the cover 3 via the pivot 4 against the rotation in the opening direction. Further, when the lever 31 pivots and the cover 3 pivots to the predetermined position C as shown in FIG. 3, the member 31a operates the switch S2 at the position corresponding to the predetermined position C. Thereby, the braking mechanism 41 operates to release the resistance applied to the cover 3 via the pivot 4. For this reason, since the cover 3 is slowly rotated and opened while rotating from the closed position A to the predetermined position C, the cover 3 is quickly rotated in the opening direction from the closed position A without any resistance and falls. There is no. Therefore, it is possible to prevent the user from inadvertently turning the cover 3 from the closed position A rapidly in the opening direction and falling down, and damaging parts attached to the cover 3 due to the impact. The cover 3 is then rotated by the user to a horizontal open position B as shown in FIG.

The member 31b is also turned by the turning of the lever 31 in the opening direction to operate the switch S3. The drive circuit operates by the operation of the switch S3, and is separated into the joint member 24 and the joint member 25 of the joint 23. Thereby, the rotation transmission from the rotation transmission mechanism to the process unit 11 is cut off. The pivot 4 also pivots in the same direction as the cover 3 pivots in the opening direction, and the member 4a provided on the pivot 4 operates the interlock switch S4 to release the power of the entire image forming apparatus main body.

Then, the recording paper P on which the paper jam has occurred in the transport path 12 by the user is transferred to the image forming apparatus main body 1.
The process unit 11 is moved out of the image forming apparatus main body 1 through the opening 2 by moving the process unit 11 in a direction perpendicular to the axial direction. As described above, in conjunction with the opening / closing operation of the cover 3 and the operation of inserting and removing the process unit 11 in a direction perpendicular to the axial direction thereof, the coupling of the joint connecting the process unit 11 and the drive mechanism is performed. By performing the separation, the process unit 11 can be efficiently moved in and out of the image forming apparatus main body 1.

When closing the cover 3 in the open position B, the user holds the cover 3 by hand and turns upward in the closing direction, and then turns the cover 3 to some extent upward. For example, while holding the second arm 34 by hand, the lever 3
1 is rotated in the closing direction, and the cover 3 is
Push the outer surface of the to the inside. When the lever 31 rotates the cover 3 to the predetermined position C, the member 31a of the lever 31 operates the switch S2 at the position corresponding to the predetermined position C,
The braking mechanism 41 operates to apply a resistance to the cover 3 via the pivot 4 against the rotation in the opening direction. Further, the lever 31 rotates and the cover 3 closes the opening 2 in the closing position A.
When the switch S1 is rotated to the position, the switch S1 at the position where the member 31a corresponds to the closing position C is operated. Thereby, the hydraulic braking mechanism 41 operates to release the resistance applied to the cover 3 via the pivot 4. For this reason, the cover 3 slowly rotates while rotating from the predetermined position C to the closing position A and comes into contact with the image forming apparatus main body 1, so that the cover 3 quickly moves from the closing position A to the closing direction without any resistance. It does not rotate and collide with the image forming apparatus main body 1.

For this reason, when the cover 3 is closed,
The image forming apparatus main body 1 does not collide with the image forming apparatus main body 1 and does not generate an impact. When the toner comes into contact with the body drum, the toner comes into contact with the recording paper conveyed along the conveyance path and becomes dirty. As a result, it is possible to prevent the occurrence of problems such as a change in the interval (width of the transport path) with the guide provided in the image forming apparatus main body 1. That is, when the cover 3 is closed, the impact caused by the collision between the cover and the image forming apparatus main body can be sufficiently absorbed to suppress the above-described problem.

The member 31b is also turned by the turning of the lever 31 in the closing direction, and the switch S3 is operated. The operation of the switch S3 activates the joint drive circuit and the joint 2
The third joint member 24 and the joint member 25 are connected. Thereby, rotation transmission from the rotation transmission mechanism to the process unit 11 becomes possible. The pivot 4 rotates in the same direction as the cover 3 rotates in the closing direction, and the member 4 provided on the pivot 4
A operates the interlock switch S4 to close the power supply of the entire image forming apparatus main body.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications. For example,
The rotation transmitting mechanism rotates the photoreceptor drum in response to the rotation from the rotation drive mechanism, and the rotation drive mechanism side and the process unit side when the process unit is moved in and out of the process unit in a direction orthogonal to the axial direction. It is also possible to use a combination of gears that can be easily connected and separated.

[0039]

According to the image forming apparatus of the first aspect of the present invention, when the cover is closed, the impact generated by the collision between the cover and the image forming apparatus main body is sufficiently absorbed, and the work provided on the image forming apparatus main body. It is possible to suppress the occurrence of an impact when the cover for opening and closing the opening for use is closed, and to prevent the occurrence of a problem due to the impact of the impact.

According to the second aspect of the present invention, the time required for the cover to rotate from the open position B to the closed position A due to resistance is short, and the impact when closing the cover without increasing the operation time for closing the cover is too long. Can be suppressed.

According to the third aspect of the invention, a paper jam often occurs from the process unit to the downstream side in the recording paper conveyance direction in the conveyance path of the image forming apparatus main body, and the cover is disposed downstream (in the upper side) in the recording paper conveyance direction. ), It is easy to take out the paper on which the paper jam has occurred from the recording paper transport path.

According to the fourth aspect of the present invention, since the cover is slowly rotated and opened while rotating from the closed position to the predetermined position, the cover is quickly rotated in the opening direction without any resistance from the closed position. Do not fall down. Therefore, it is possible to prevent the user from inadvertently turning the cover from the closed position A rapidly in the opening direction and falling down, and the impact may damage components attached to the cover.

According to the fifth aspect of the present invention, the provision of the levers on both sides in the width direction of the cover is for rotating the cover stably and stably reaching the closed position and the open position. Thus, the transfer device and the guide provided on the cover can be accurately positioned when the cover is closed. The configuration of this lever is simple and effective as a member for operating a cover described later.

According to the sixth aspect of the present invention, the effect of the first aspect of the present invention can be greatly enhanced if the opening of the image forming apparatus main body is for inserting and removing the image forming mechanism.

According to the seventh aspect of the present invention, the image forming mechanism and the drive mechanism are connected to each other in accordance with the operation of inserting and removing the image forming mechanism in a direction perpendicular to the axial direction in conjunction with the opening and closing operation of the cover. By connecting and separating the joints that connect the image forming apparatus, the image forming mechanism can be efficiently inserted into and removed from the image forming apparatus main body.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically illustrating an appearance of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a cover and a peripheral portion of the cover in the image forming apparatus according to the embodiment;

FIG. 3 is a cross-sectional view schematically illustrating a cover and a peripheral portion of the cover in the image forming apparatus according to the embodiment.

FIG. 4 is a cross-sectional view schematically showing a cover and a peripheral portion thereof in the image forming apparatus according to the embodiment.

FIG. 5 is a perspective view schematically showing a cover and a peripheral edge of the cover in the image forming apparatus of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus main body, 2 ... Opening, 3 ... Cover 4 ... Axis 11 ... Process unit 16 ... Fixing device 18 ... Guide 19 ... Guide 21 ... Process unit side rotary shaft 22 ... Main body side rotary shaft 23 ... Joint 24 ... Joint Member 25 ... Coupling member 31 ... Lever 32 ... Lever shaft 33 ... First arm 34 ... Second arm 41 ... Hydraulic braking mechanism S1 ... Switch S2 ... Switch S3 ... Switch S4 ... Switch

Continued on the front page F-term (reference) 2C061 AQ06 BB08 BB35 CD01 2H027 DA26 DE03 ED30 ZA03 2H071 AA13 AA17 AA19 AA42 BA13 CA01 CA05 CA07 CA09 4E360 AB08 AB12 BA04 BB02 BB12 BB16 BB22 BC03 BC12 EA18 EB18 FA04

Claims (7)

[Claims] An image forming apparatus main body including an image forming mechanism and a conveying path for conveying recording paper so as to pass through the image forming mechanism, and an opening facing the conveying path; A part which is pivotally supported by the image forming apparatus main body so as to rotate between a closed position for closing the opening and an open position outside the image forming apparatus main body for opening the opening and forms the transport path on the inner surface is provided. Applying a resistive force to the cover attached to the image forming apparatus main body to prevent the cover from turning to the closed position at a predetermined position in the process of turning the cover from the open position to the closed position. An image forming apparatus comprising: a cover operating unit. 2. The image forming apparatus according to claim 1, wherein the predetermined position at which a resistance force is applied to the cover is a position near the opening. 3. The image forming apparatus according to claim 1, wherein the cover has an open-side front end located downstream of the transport path with respect to a base end. 4. The cover operating means applies a resisting force for suppressing the rotation of the cover from the closed position to the open position up to a predetermined position in the process of rotating the cover from the closed position to the open position. The image forming apparatus according to claim 1. 5. The cover operating means includes a lever that rotates between the closed position and a predetermined position in the process of rotating the cover in the closed direction in conjunction with the rotation of the cover. The image forming apparatus according to claim 1, wherein: 6. The image forming apparatus according to claim 1, wherein the opening is for taking in and out the image forming mechanism. 7. An image forming mechanism, which is rotated and transmitted from a rotary drive mechanism via a joint and driven to record an image on a recording sheet, and inserts the image forming mechanism in a direction perpendicular to an axial direction. An image forming apparatus main body having an opening for withdrawal, a cover provided in the image forming apparatus main body for opening and closing the opening, and the joint when the cover is closed in conjunction with the opening and closing operation of the cover. And a means for connecting the joint when the cover is open.