JP2003015373A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove even a sheet retained at the inside of a device main body in any state from an aperture part. SOLUTION: A copying machine 100 is provided with the device main body 106 having the aperture part 575, an image reading part 520 provided at the device main body so as to be movable back and forth and to open and close the aperture part, an image forming part 570 provided at the inside of the device main body and to form a toner image on the sheet, a fixing part 580 to fix the toner image on the sheet, a driving system 103 having several gears to transmit the rotational force of a main motor 110 to the fixing part 580 and a rotational force transmission release part 107 by which a rocking gear 122 out of the driving system 103 is separated from/brought into contact with an idler gear 123 in accordance with the opening/closing operation of the image reading part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine for forming an image on a sheet, a facsimile, a printer, and a composite machine of these.

[0002]

2. Description of the Related Art Generally, an image forming apparatus is provided with an image forming section for forming a toner image on a sheet and a fixing section for fixing the toner image on the sheet by the image forming section. The fixing unit rotatably conveys the sheet to which the toner image has been transferred by the image forming unit with a pressure roller and a fixing roller having a built-in heater, and heats and presses the sheet to fix the toner image on the sheet. ing.

However, the sheet passing between the fixing roller and the pressure roller adheres to the surface of the fixing roller due to the toner of the toner image depending on various conditions such as the heating temperature of the fixing roller and the type of the sheet, thus clogging the sheet. Sometimes caused. In the fixing unit using a belt-shaped film instead of the roller, the belt was stuck to the film and the sheet was jammed.

The jammed sheet can be removed by the user. The configuration to be removed differs depending on each image forming apparatus.

A conventional image forming apparatus 400 shown in FIG.
Is a clamshell type (so-called crocodile type) image forming apparatus. The image forming apparatus 400 also includes an image forming unit (not shown) that forms a toner image on the sheet, and a fixing unit 420 that fixes the toner image on the sheet by the image forming unit. The fixing unit 420 rotatably conveys the sheet on which the toner image has been transferred by the image forming unit with a pressure roller and a fixing roller having a built-in heater, and heats and presses the sheet.
The toner image is fixed on the sheet.

The image forming apparatus 400 can remove a sheet when the sheet stays around the fixing section 420. Therefore, in the image forming apparatus 400, when the upper frame 401 is lifted, the upper frame 401 is rotated upward by the one-side hinge mechanism (not shown) arranged on the right side in the figure opposite to the fixing unit 420,
The upper side of the fixing unit 420 provided on the lower frame 402 can be opened.

When the upper frame 401 is lifted, the upper frame 401
The drive unit 410 disposed on the side also rotates together with the upper frame 401. The drive gear provided on the inner side of the fixing unit 420 on the fixing unit 420 side and the gear (not shown) on the driving unit 410 side release the mesh. As a result, the fixing roller and the pressure roller in the fixing unit 420 can freely rotate in the sheet conveying direction (downstream direction) and in the opposite direction (upstream direction). become.

At this time, the fixing roller and the pressure roller sandwich and hold the sheet staying in the fixing section 420. Therefore, the user can pull out the staying sheets in the direction of arrow C (downstream direction) or in the direction D (upstream direction) with some pulling force in the figure. Therefore, the user can easily pull out the accumulated sheet.

Another conventional image forming apparatus 5 shown in FIG.
00 is a smaller size, lower cost (lower price of products),
This is a so-called digital copying machine. This image forming apparatus 50
0 is the clamshell type image forming apparatus 4 shown in FIG.
Compared to 00, the hinge mechanism for opening and closing the crocodile, which is a component necessary for pulling out the jam of the sheet, and the strength increase of the frame are unnecessary, and the configuration is advantageous for lowering the cost. ing.

The image forming apparatus 500 is mainly composed of an upper document reading section 520 and a lower image output section 550. The original to be copied is the original reading section 5
Read at 20. The information read by the document reading unit 520 is converted into an image signal, and then the image output unit 550.
Laser scanner 540. Sheet supply unit 56
The sheet S stored in 0 is the sheet supply roller 561,
The sheet is conveyed by the pair of conveying rollers 562 and 112 and sent to the image forming unit 570. In the image forming section 570, the photosensitive drum 5 is irradiated with the laser beam from the laser scanner 540.
At 72, a latent image is formed, and the latent image is developed to form a toner image. The sheet S sent to the image forming unit 570 is transferred with the toner image in time with the toner image. Finally, the sheet S is fixed to the fixing unit 5.
After the toner image is permanently fixed at 80, the toner image is discharged outside the apparatus main body.

In the image forming apparatus 500, as shown in FIG. 17, when the user horizontally moves the document reading section 520 in the direction of arrow T in the figure, the sheets accumulated in the apparatus main body 501 are removed, the process cartridge 571, etc. Consumables can be easily replaced.

The document reading unit 520 moves between a position (first position) in which the apparatus body 501 is closed as shown in FIG. 16 and a position (second position) in which the apparatus body 501 is opened as shown in FIG. It is supposed to do. On the bottom of the frame 522,
Engaging portions 526 and 527 are provided. A top cover 555 is provided on the upper surface of the image output unit 550. The top cover 555 includes engagement portions 526, 52.
An elongated groove portion that engages with 7 is formed. Frame 522
Is an integrally molded resin product for cost reduction.

The user rotates the lever 553 provided on the image output section 550 side in the direction of arrow V to integrally form the locking section 521 and the lever 553 provided on the frame body 522 of the document reading section 520. When the engagement with the molded hook portion 554 is released, the document reading portion 520 becomes movable.

When the user pushes the document reading unit 520 in the direction of arrow T in the drawing after rotating the lever 553, the document reading unit 520 moves horizontally. As a result, the inside of the apparatus main body 501 of the image forming apparatus 500 is opened. At this time, the engaging portions 526 and 527 move in the groove portion while engaging with the groove portion and guide the movement of the document reading portion 520. The amount of horizontal movement of the document reading unit 520 is determined by the length of the groove. By the way, the moving distance of the image forming apparatus 500 and the length of the groove are about 180 mm.

The opening 575 is exposed on the upper surface of the image output unit 550 by the horizontal movement of the document reading unit 520. In this state, the process cartridge 571 is inserted into the opening 5
It can be pulled out in the direction of arrow U from 75. Further, the sheet accumulated around the image forming unit 570 can be taken out by inserting the process cartridge 571 in the U direction in the drawing through the opening 575 and then inserting the hand into the opening 575.

The document reading unit 520 in the state shown in FIG. 16 is biased and positioned in the T direction by a coil spring (not shown).

[0017]

However, the conventional image forming apparatus 500 may have difficulty in post-processing depending on the accumulated state of accumulated sheets (retained sheets).

As an example thereof, a staying sheet (denoted by reference numeral SJ in FIG. 17) that has passed through the fixing section 580 but has not reached the sheet discharging section 590 is removed from the opening section 575. .

At this time, from the sheet discharging section 590 side,
The staying sheet SJ cannot be pulled out of the apparatus main body 501. That is, the staying sheet SJ cannot be pulled out because it is nipped by the fixing unit 580 including the fixing roller 581 and the pressure roller 582 that are in contact with each other and pressed. Moreover, since the fixing unit 580 meshes with a gear provided in a drive unit (not shown) disposed on the inner side (rear side) in the apparatus main body 501, the fixing unit 580 is in the arrow W direction (sheet conveying direction) in the drawing. Cannot rotate in the opposite direction. Also,
Even if the staying sheet SJ is pulled out from the opening 575 in the U direction in the drawing, it cannot be pulled out. When it is forcibly pulled out, the staying sheet SJ is torn in the middle, and it becomes more difficult to remove the remaining staying sheet SJ.

According to the present invention, how to stay in the main body of an image forming apparatus without impairing the downsizing and the cost reduction which are the features of the image forming apparatus which is horizontally movable with respect to the image output unit and provided with the opening / closing means. It is an object of the present invention to provide an image forming apparatus capable of removing even such a sheet from the opening exposed by the horizontal movement of the opening / closing means.

[0021]

In order to achieve the above object, an image forming apparatus of the present invention includes an apparatus main body having an opening, and an opening / closing for reciprocatingly provided in the apparatus main body to open / close the opening. Means, an image forming means for forming a toner image on a sheet provided in the main body of the apparatus, a pair of sheet conveying rotary bodies for conveying the sheet, and a rotational force of a driving source to the pair of sheet conveying rotary bodies. With the rotating body row having a plurality of rotating bodies and the opening / closing operation of the opening / closing means,
Rotational force transmission canceling means for contacting at least one rotating body of the rotating body row with another rotating body so as to be spaced apart from each other.

The rotational force transmission canceling means of the image forming apparatus of the present invention is adapted to move the at least one rotating body in a direction intersecting the rotation axis of the other rotating body.

The rotational force transmission canceling means of the image forming apparatus of the present invention is adapted to move the at least one rotating body in the thrust direction.

In the image forming apparatus of the present invention, the rotating shaft of the rotating body of the rotating body array is horizontally arranged, and the rotating force transmission canceling means is an operating member provided in the opening / closing means, and the at least one at least one. And a member to be actuated for moving the supported rotating body upward by abutting the operating member.

In the image forming apparatus of the present invention, the rotary shaft of the rotary body of the rotary body row is arranged horizontally, and the rotational force transmission canceling means includes an operating member provided in the opening / closing means and the operating member. A rotary member that rotates by abutting, an actuated member that movably supports the at least one rotary member in the vertical direction, and the rotary member and the actuated member are connected to each other,
And a connecting member that causes the actuated member to perform an operation of moving the rotating body supported by the actuated member upward when the actuating member abuts the rotary member.

The rotational force transmission canceling means of the image forming apparatus of the present invention moves the at least one rotating body in the thrust direction by contact between the actuating member provided on the opening / closing means and the actuating member. And an actuated member which is separated from the rotating body.

The opening / closing means of the image forming apparatus of the present invention comprises:
The document reading unit is capable of horizontally reciprocating the document.

The sheet conveying rotary member pair of the image forming apparatus of the present invention is a transfer rotary member pair for transferring the toner image formed by the image forming means onto the sheet.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION A copying machine which is an image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. The image forming apparatus of the present invention is not limited to the copying machine. The present invention can also be applied to a facsimile, a printer, a complex machine of these, and the like.

(Copier of First Embodiment) FIG. 1 is a schematic front view of the copier of the first embodiment, in which a drive system for a fixing unit and a sheet feeding unit is omitted. FIG. 2 is a view of the copying machine of FIG. 1 in a state where the opening of the apparatus main body is opened by the image reading unit. FIG. 3 is a front view of the drive system of the fixing unit and the sheet feeding unit of the copying machine of FIG. FIG. 4 is a plan view of the drive system of the fixing unit shown in FIG. 5A and 5B are views of the drive release lever of the drive system in FIG. 3, where FIG. 5A is a front view, FIG. 5B is a plan view, and FIG. 5C is a right side view of FIG. FIG. 6 shows FIG.
FIG. 9 is a state diagram when removing the accumulated sheet by opening the opening from that state. FIG. 7 is an enlarged view when the drive release lever of the drive system in FIG. 3 operates.

The copying machine 100 of the first embodiment is downsized,
This is a so-called digital copying machine with low cost (product price reduction). The copying machine 100 mainly includes an original reading unit (opening / closing unit) 520 on the upper side and an image output unit 10 on the lower side.
It is composed of 1 and 1. The document to be copied is read by the document reading unit 520. Document reading unit 52
The information read by 0 is converted into an image signal and then sent to the laser scanner 540 of the image output unit 101. The sheet S stored in the sheet supply unit 560 is conveyed by the sheet supply rollers 561 and 112 and the conveyance roller pair 562 and is sent to the image forming unit (image forming unit) 570.
In the image forming unit 570, a latent image is formed on the photosensitive drum 572 by the laser beam from the laser scanner 540, and the latent image is developed to form a toner image. The sheet S sent to the image forming unit 570 is
The toner image is transferred in time with the toner image. Finally, the sheet S includes a fixing unit 58 including a fixing roller (a pair of sheet conveying rotary body and a pair of transfer rotating body) 581 and a pressure roller (a pair of sheet conveying rotary body and a pair of transfer rotating body) 582.
After the toner image is permanently fixed at 0, the toner image is discharged outside the apparatus main body.

As shown in FIG. 2, when the user horizontally moves the document reading unit 520 in the direction of arrow T in the copying machine 100, the copying machine 100 removes the sheets accumulated in the apparatus main body 501, processes cartridge 571, and the like. Consumables can be easily replaced.

The document reading section 520 moves between a position (first position) in which the apparatus body 501 is closed shown in FIG. 1 and a position (second position) in which the apparatus body 501 is opened shown in FIG. It is supposed to do. Engagement portions 526 and 527 are provided on the bottom surface of the frame body 522. In addition, the image output unit 10
A top cover 555 is disposed on the upper surface of the No. 1. The top cover 555 has elongated grooves that engage with the engaging portions 526 and 527. The frame body 522 is a resin product integrally molded for cost reduction.

The user rotates the lever 553 provided on the image output unit 101 side in the direction of arrow V to integrally engage the locking unit 521 and the lever 553 provided on the frame body 522 of the document reading unit 520. When the engagement with the molded hook portion 554 is released, the document reading portion 520 becomes movable.

After the user rotates the lever 553 and pushes the document reading unit 520 in the direction of arrow T in the figure, the document reading unit 520 moves horizontally. As a result, the copier 1
The inside of the apparatus main body 501 of 00 is opened. At this time, the engaging portions 526 and 527 move in the groove portion while engaging with the groove portion and guide the movement of the document reading portion 520. The amount of horizontal movement of the document reading unit 520 is determined by the length of the groove. By the way, the moving distance of the copying machine 100 and the length of the groove are about 180 mm.

The horizontal movement of the document reading unit 520 exposes the opening 575 on the upper surface of the image output unit 101. In this state, the process cartridge 571 is inserted into the opening 5
It can be pulled out in the direction of arrow U from 75. Further, the sheet accumulated around the image forming unit 570 can be taken out by inserting the process cartridge 571 in the U direction in the drawing through the opening 575 and then inserting the hand into the opening 575.

The copying machine 100, which is an image forming apparatus, includes a sheet supply roller 561 of a sheet supply unit 560, a photosensitive drum 572 of an image forming unit 570, a fixing roller 581 of a fixing unit 580, and the like, which are indicated by a two-dot chain line. It has one motor (driving source) 110.

In the drive system 102 of the copying machine 100, the gear train arranged from the output gear 111 of the main motor 110 to the left in FIG.
03 and the output gear 111 of the main motor 110 from FIG.
The gear train arranged in the middle right direction is configured by the drive system 104 to the sheet supply unit 560.

Since the present embodiment relates to the structure of the drive system 103 for transmitting the driving force to the fixing unit 580, the structure of the drive system 103 to the fixing unit side will be described below to the sheet supply unit side. The description of the configuration of the drive system 104 is omitted.

As shown in FIG. 4, the main body 1 of the copying machine 100.
A drive unit 105 is provided on the back side (rear side) of 06. The drive unit 105 includes a main motor 110, a plurality of gears, a drive release lever (actuated member) 130, and a drive side plate 1.
It is composed of 50 etc.

The main motor 110 is adapted to rotate at a predetermined number of revolutions according to a control signal from a control unit (not shown) and then stop. As shown in FIG. 3, the rotational force of the main motor 110 is generated by the output gear 111, the step gear 121,
Swing gear 122, idler gear 123, step gear 124,
It is transmitted through the idler gear 125 to the fixing gear 585 provided in the fixing unit 580. Therefore, the fixing roller 581 rotates in the clockwise direction as each gear rotates in the direction of the arrow in FIG. The gears from the output gear 111 to the fixing gear 585 are rotating bodies. The axis of each gear is horizontal.

As shown in FIG. 5, the step gear 121 and the swing gear 122 are provided so as to be fitted in the drive release lever 130. The drive release lever 130 is, for example,
It is a resin molded product made of polyoxymethylene (POM).
The step gear 121 and the swing gear 122 are used for the drive release lever 13
The side surfaces 132a and 132b of the case portion 132 of FIG.
In (c), open a little in the direction of arrow K,
The drive release lever 130 is rotatably mounted by being pushed into a locking hole formed in 32b. Therefore, the drive release lever 130 has a function as a bearing for the step gear 121 and the swing gear 122.

The drive release lever 130, in which the step gear 121 and the swing gear 122 are incorporated, inserts the hole 121a formed at the center of the step gear 121 into the shaft 140 provided on the drive side plate 150 to drive the drive unit. It is attached to 105.

Therefore, the drive release lever 130 and the swing gear 122 swing around the shaft 140. Further, the swing gear 122 is provided with the drive release lever 130.
The swing of the gear meshes with or separates from the idler gear 123.

Next, the original reading unit 520 is changed to the one shown in FIG.
The movement of the drive release lever 130 when the apparatus main body 106 of the copying machine 100 is stopped at the opened position (second position) in the direction of the arrow T will be described with reference to FIGS. 6 and 7. To do.

When the document reading unit 520 is horizontally moved to the second position as shown in FIG. 6, the opening 575 is exposed on the upper right surface of the image output unit 101 in the figure, and the process cartridge 571 can be replaced or the process cartridge 571 can be replaced. After removing 571, it becomes possible to perform maintenance such as removal of accumulated sheets in the apparatus body 106 and replacement of parts in the apparatus body 106 (see FIG. 2).

At this time, the engaging portion 131 provided on the drive release lever 130 has the inner wall surface 522a of the frame 522.
It rides on a protrusion (actuating member) 165 provided on (see FIG. 4). Therefore, the drive release lever 130 is
6, the swing gear 122 is separated from the idler gear 123, and disengaged from the idler gear 123. Further, the fixing roller 581 is in a rotatable state and can rotate in the counterclockwise direction in the drawing. Therefore, the device body 1
The sheet accumulated in 06 can be removed by pulling it back from the opening 575 to the upstream side in the sheet conveying direction. The drive release lever 130, the engaging portion 131, the protrusion 16
5 and the like constitute a rotational force transmission canceling section (rotating force canceling means) 107.

In FIG. 7, the drive release lever 130 shown by the solid line is in the drive release position where the swing gear 122 and the idler gear 123 are out of mesh with each other. The drive release lever 130 shown by a broken line shows a drive transmission position where the swing gear 122 and the idler gear 123 mesh with each other. An alternate long and short dash line of each gear indicates a reference pitch circle of the gear.

In FIG. 7, the projection portion 165 is provided with the inclined surface portion 1 just before the document reading portion 520 reaches the second position.
65b abuts on the engaging portion 131 so that the drive release lever 130
When the document reading unit 520 reaches the second position after the start of the swinging, the engaging portion 131 is mounted on the back wall surface 522a (see FIG. 4) so as to ride on the flat surface portion 165a. Since the opening 575 is closed, the document reading unit 5
When 20 is horizontally moved in the direction of arrow TS in FIG. 7, the protrusion 165 separates from the engaging portion 131, and the drive release lever 130 contacts the rotation stop (not shown) counterclockwise by its own weight. Turning around the shaft 140, FIG.
Stop at the position indicated by the broken line. Then, the swing gear 122
Engages the idler gear 123 again. Therefore,
The drive release lever 130 swings around the shaft 140 in the direction of arrow Z in FIG. 7 depending on whether or not it is in contact with the protrusion 165.

As described above, the copying machine 100 is
By interlocking with the horizontal movement of the document reading unit 520, the drive release lever 130 is swung to engage the drive gear train from the main motor 110 to the fixing unit 580 and release the engagement. There is. Therefore, in the copying machine 100, the user simply horizontally moves the document reading unit 520 to the position where the apparatus main body 106 is opened (second position), and the swing gear 122 is automatically moved to the idler gear 12.
3, the fixing roller 581 can be rotated in the direction opposite to the sheet conveying direction.

Therefore, the copying machine 100 includes the fixing unit 58.
Even a staying sheet that is sandwiched between 0 and is difficult to take out in the past can be easily pulled out by the user putting his / her hand through the opening 575. Similarly, the process cartridge 571 can be easily replaced.

Moreover, the copying machine 100 includes the image output unit 10
A document reading section 5 provided so as to be horizontally movable with respect to 1.
Since the accumulated sheet is easily removed by utilizing the movement of 20, it is possible to maintain the features such as downsizing of the copying machine and cost reduction.

(Copier of Second Embodiment) Next, a copier of a second embodiment of the present invention will be described with reference to FIGS.

The copying machine according to the second embodiment is different from the copying machine according to the first embodiment in the portion relating to the fixing section.
The different part will be mainly described, and description and drawings of other parts will be omitted.

FIG. 8 is a front view of the drive system of the copying machine of the second embodiment. FIG. 9 is a state diagram when removing the accumulated sheet by opening the opening from the state of FIG.

In FIG. 8, the drive unit 20 of the copying machine 200
5 includes a gear holder 230 in which a step gear 121 and a swing gear 122 are incorporated. Gear holder 2
The method of incorporating the step gear 121 and the swing gear 122 into the step gear 30 is as follows.
21 and the swing gear 122 are assembled in the same manner. Therefore, the description of how to install is omitted.

The gear holder 230 is provided with an engaging portion 230c. A release lever 232 incorporated in the drive unit 205 is rotatably provided on a drive side plate (a side plate corresponding to the drive side plate 150 in FIG. 2) (not shown) of the drive unit 205. The release lever 232 is configured such that the hole 232a is inserted into a shaft (not shown) provided on the drive side plate and is rotated about the shaft (not shown) and the hole 232a. The release lever 232 is provided with an engaging portion 232c.

As shown in FIG. 8, the gear holder (actuated member) 230 and the release lever (rotating member) 232 have release links (connecting members) at their respective engaging portions 230c and 232c.
It is connected by 231. Therefore, when the release lever 232 swings, the gear holder 230 receives the swinging force of the release lever 232 via the release link 231 and
It swings around the shaft 140.

The release lever 232 is provided with an abutting portion 232b on the opposite side (upper side in the figure) with the hole 232a as a boundary. Further, a pushing portion (actuating member) 265 is formed on the bottom surface 522b of the frame body 522.

The gear holder 230 and the release link 2
31, the release lever 232, the pushing portion 265 and the like constitute a rotational force transmission releasing portion (rotational force releasing means) 108.

FIG. 9 shows a document reading section (opening / closing means) 520.
It is a figure when it is horizontally moved and it is moved to the 2nd position. When the document reading unit 520 is moved to the second position, the pushing unit 265 contacts the abutting portion 232b of the release lever 232.
Is formed at a position where it abuts against. As shown in FIG. 9, the release lever 232 rotates counterclockwise in the figure around the hole 232a when the pushing portion 265 abuts on the abutting portion 232b.

Then, the release link 231 is pulled to the right in the figure (in the direction of the arrow) to move the gear holder 230 into the shaft 1.
With 40 as the center of rotation, it is pulled upward in the clockwise direction (arrow direction) in the figure. As a result, the rocking gear 122 is disengaged from the idler gear 123 and the fixing roller 5 is released.
81 becomes rotatable. Then, the fixing roller 58
1 can also rotate counterclockwise in the figure.

Therefore, the user can easily remove the staying sheet, which is sandwiched and retained by the fixing unit 580, from the opening 575 to the upstream side in the sheet conveying direction and is easily removed.

When the document reading section 520 is returned in the TS direction in the figure, the pushing section 265 separates from the contact section 232b. The gear holder 230 rotates by its own weight around the shaft 140 in the counterclockwise direction in the drawing until it comes into contact with a rotation stopper (not shown), and the swing gear 122 meshes with the idler gear 123.

Although the copying machine 200 of the second embodiment is provided with the release link 231, the release link 231 is
Not necessarily required. The release lever 232 and the gear holder 230 may be directly connected by a shaft and a vertically elongated hole.

As described above, the copying machine of the second embodiment is
The user can easily remove the staying sheet that is pinched by the fixing unit 580 and stayed, by pulling it from the opening 575 to the upstream side in the sheet conveying direction.

Moreover, the copying machine 100 has the image output unit 20.
A document reading section 5 provided so as to be horizontally movable with respect to 1.
Since the movement of 20 is used, it is possible to maintain the features such as downsizing of the copying machine and cost reduction.

In the copying machine 200 of the second embodiment, the drive release lever 130 of the first embodiment is provided inside the frame 522 due to the restriction of the internal structure of the document reading unit 520 (for example, the arrangement of the drive unit and the board). As described above, the structure can be applied when there is no space for disposing the rotational force transmission canceling portion extending upward.

Further, in the copying machine 200 of the second embodiment, the release lever 232 and the release link 231 increase the degree of freedom in the internal structure of the document reading section 520, and the upper side of the document reading section 520 is provided with an automatic document feeder or the like. It has a structure that makes it easy to equip it with related equipment for copying machines.

(Third Embodiment) Next, FIGS.
A copying machine according to a third embodiment of the present invention will be described based on FIG.

The copying machine according to the third embodiment is also different from the copying machine according to the first embodiment in the part relating to the fixing unit.
The different part will be mainly described, and description and drawings of other parts will be omitted.

FIG. 10 is a front view of the drive system of the copying machine of the third embodiment. FIG. 11 is a diagram of the drive contact / separation cam of FIG. 10 viewed from the right side. FIG. 12 is a plan view of FIG. 11. FIG. 13 is a state diagram when removing the accumulated sheet by opening the opening from the state of FIG. FIG. 14 is a diagram of the drive contact / separation cam in FIG. 13 viewed from the right side.

As shown in FIG. 10, the basic structure of the transmission path of the rotational torque from the main motor 110 in the copying machine 300 is the copying machines 100 and 200 of the first and second embodiments.
Is the same as the transmission route of. However, in the copying machine 300 of the present embodiment, the swing gear 1 of the first and second embodiments is used.
22 is replaced with an idler gear 332 that is rotatably provided on a shaft 331 (see FIG. 10) fixed by caulking to the drive side plate 350 shown in FIG. Also,
A shaft 33 in which the idler gear 125 of the first and second embodiments is fixed to the driving side plate 350 shown in FIG. 11 by swaging.
7 is replaced with an idler gear 335 movably and rotatably in the thrust direction.

A drive contact / separation cam (actuated member) 360 is incorporated in the drive unit 305. In FIG. 10, the drive contact / separation cam 360 is an original reading unit (opening / closing means) 520.
When in the first position with the opening 575 closed, it is in the position raised by the tension spring 361. At this time, as shown in FIG. 10, with respect to the upper end 360a of the drive contact / separation cam 360, the frame 522 of the document reading unit 520 is attached.
Projection (operating member) 390 provided on the bottom surface 522b of the
Are apart. Further, the lower end 360b is also the idler gear 3
Away from 35.

Next, the positioning of the drive contact / separation cam 360 will be described with reference to FIGS. 11 and 12 when the document reading unit 520 is in the first position with the opening 575 closed.

As shown in FIGS. 11 and 12, the drive contact / separation cam 360 has the lower end of the shaft portion 360c inserted into a hole (not shown) formed in the cut-and-raised portion 350a of the drive side plate 350, and the upper end is positioned. It is inserted into the member 362 and provided on the drive side plate 350 so as to be vertically movable. Further, the drive contact / separation cam 360 is pulled in the direction of the arrow in FIG. 11 by the tension spring 361 to contact the contact portion 360e of the shaft portion 360c.
Is brought into contact with the positioning member 362 and its rising is restricted.

The drive contact / separation cam 36 when the contact portion 360e contacts the positioning member 362 and its rising is restricted.
0 separates the lower end 360b from the idler gear 335 as shown in FIG. Therefore, the idler gear 33
5 is urged to the right in the drawing by a compression spring 338 and is in contact with a flange portion 337b at the base of the shaft 337 (the caulking side of the shaft). Therefore, the idler gear 335 meshes with the step gear 124 and transmits the rotational force from the main motor 110 to the fixing unit 580.

The driving contact / separation cam 360 and the tension spring 36
1, the compression spring 338, the protruding portion 390, and the like constitute a rotational force transmission canceling portion (rotating force canceling means) 109.

In FIG. 13, when the document reading section 520 moves to the second position where the opening 575 is opened, the projection 390 abuts on the upper end 360a of the drive contact / separation cam 360, and the drive contact / separation cam. Depress 360 against tension spring 361. Incidentally, the descending distance of the drive contact / separation cam 360 at this time is about 5.5 mm.

Immediately before the original reading unit 520 reaches the second position, the projection 390 starts contacting the inclined surface 390a with the upper end 360a of the drive contact / separation cam 360, and the original reading unit 520 moves to the second position. When it reaches the plane part 39
It is arranged on the bottom surface 522b of the frame 522 so that the drive contact / separation cam 360 is pushed down to the lowest point by 0b.

When the drive contact / separation cam 360 is pushed down by the abutment of the protrusion 390 against the pulling force of the tension spring 361, the lower end 360b of the drive contact / separation cam 360 is, as shown in FIG. Abut 335. Since the idler gear 335 is freely provided in the thrust direction on the shaft 337, as the lower end 360b descends,
While compressing the compression spring 338 loosely fitted to the shaft 337, the compression spring 338 is moved in the direction of the arrow in FIG. 14 to disengage from the step gear 124, and the main motor 110 to the fixing unit 5 is released.
The rotational force to 80 is not transmitted.

Therefore, the fixing roller 581 is rotatable and can be rotated counterclockwise in FIG. Therefore, the user can easily remove the staying sheet that is pinched by the fixing unit 580 and stays, from the opening 575 to the upstream side in the sheet conveying direction, and easily remove the staying sheet.

When the document reading unit 520 moves to the first position where the opening 575 is closed, the protrusion 390 separates from the drive contact / separation cam 360. Then, the drive contact / separation cam 360
Is pulled up to a raised position by a tension spring 361.
At the same time, the descending end 360b separates from the idler gear 335. Further, the idler gear 335 is pushed by the compression spring 338 to move in the thrust direction on the shaft 337, and again meshes with the step gear 124 so that the rotational force of the main motor 110 can be transmitted to the fixing portion 580.

As described above, the copying machine of the third embodiment also
The user can easily remove the staying sheet that is pinched by the fixing unit 580 and stayed, by pulling it from the opening 575 to the upstream side in the sheet conveying direction.

Moreover, the copying machine 300 includes the image output unit 30.
A document reading section 5 provided so as to be horizontally movable with respect to 1.
Since the movement of 20 is used, it is possible to maintain the features such as downsizing of the copying machine and cost reduction.

Although the fixing unit 580 includes the fixing roller 581 and the pressure roller 582 in the copying machines of the first to third embodiments, the fixing unit 580 is not limited to this structure, and the fixing unit 580 is generally used. The fixing unit may include a heater unit instead of the fixing roller).

In the copying machines of the first to third embodiments, the gear train consisting of a plurality of gears is used to transmit the rotation of the main motor 110 to the fixing section 580, but the gear train is not limited to the gears. Instead of the gear, a roller row composed of a plurality of rollers may be used.

Further, in the copying machines of the first to third embodiments, the fixing roller 581 of the fixing unit 580 can be set in a rotatable state.
12 is rotated by a gear train from the main motor 110, the transport roller pairs 562, 112 are set in a rotatable state, and the transport roller pairs 562, 112 (sheet transport rotary body pair, transfer rotary body pair) are jammed. The sheet may also be made easy to remove.

[0089]

According to the image forming apparatus of the present invention, at least one of the rotating bodies in the rotating body row for transmitting the rotational force of the drive source to the pair of sheet conveying rotating bodies is replaced by the other rotating body in accordance with the opening / closing operation of the opening / closing means. Since it is configured to be in contact with the rotating body at a distance, the image forming apparatus can be sandwiched between the sheet conveying rotating body pair without impairing the features such as downsizing and cost reduction. The user can easily pull out the staying sheet, which has been difficult to take out in the past, by putting his / her hand through the opening.

[Brief description of drawings]

FIG. 1 is a schematic front view of a copying machine according to a first embodiment, in which a drive system for a fixing unit and a sheet supply unit is omitted.

FIG. 2 is a view showing a state in which an opening of an apparatus main body is opened by an image reading unit in the copying machine of FIG.

3 is a front view of a drive system of a fixing unit and a sheet supply unit of the copying machine of FIG.

FIG. 4 is a plan view of a drive system of the fixing unit shown in FIG.

5 is a diagram of a drive release lever of the copying machine of FIG.
(A) is a front view. (B) is a plan view. (C)
FIG. 7A is a right side view of (a).

FIG. 6 is a state diagram when removing the accumulated sheet by opening the opening from the state of FIG. 3;

7 is an enlarged view when the drive release lever of the copying machine of FIG. 3 is activated.

FIG. 8 is a front view of a drive system of the copying machine according to the second embodiment.

FIG. 9 is a state diagram when removing the accumulated sheet by opening the opening from the state of FIG. 8;

FIG. 10 is a front view of a drive system of a copying machine according to a third embodiment.

11 is a diagram of the drive contact / separation cam of FIG. 10 viewed from the right side.

FIG. 12 is a plan view of FIG. 11.

FIG. 13 is a state diagram when the retained sheet is removed by opening the opening from the state of FIG. 10;

FIG. 14 is a diagram of the drive contact / separation cam in FIG. 13 viewed from the right side.

FIG. 15 is an external perspective view of a conventional copying machine.

FIG. 16 is an external view of another conventional copying machine.

FIG. 17 is a diagram showing a state in which the opening is opened in the copying machine of FIG.

[Explanation of symbols]

S sheet 100, 200, 300 Copier (image forming apparatus) 101 Image output unit 102 Drive system 103 Drive system to fixing unit (rotating body row) 104 Drive system to sheet supply unit 106 Copier (image forming apparatus) Main bodies 107, 108, 109 Rotational force transmission canceling section (rotational force canceling means) 110 Main motor (driving source) 111 Output gear (rotating body) 112 Conveying roller pair (sheet conveying rotating body pair, transfer rotating body pair) 121 step gear (Rotating body) 122 Oscillating gear (rotating body) 123 Idler gear (rotating body) 124 Step gear (rotating body) 125 Idler gear (rotating body) 130 Drive release lever (actuated member) 131 Engaging portion 165 Projection portion (actuating member) ) 165a Planar part 165b Sloping part 230 Gear holder (actuated member) 231 Release link (connecting member) 232 Release lever (rotation) Member) 265 Pushing unit (Operating member) 337 Shaft 338 Compression spring 360 Drive contact / separation cam (Actuated member) 361 Tensile spring 362 Positioning member 390 Protrusion (Operating member) 520 Document reading unit (Opening / closing unit) 562 Conveying roller (Sheet) Conveying rotator pair, Transfer rotator pair) 570 Image forming unit (image forming unit) 571 Process cartridge 572 Photosensitive drum 575 Opening 580 Fixing unit 581 Fixing roller (sheet conveying rotator pair) 582 Pressure roller (sheet conveying rotator) Pair) 585 Fixing gear (rotating body)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H071 AA05 AA13 AA18 BA04 BA13                       BA20 CA05 DA02 DA06 DA08                       DA09 DA12 DA27 EA04                 2H072 AA02 AA11 AA22 EA15 EA16                       JA02                 2H200 FA12 GA23 GA34 GB22 GB25                       GB30 GB41 JB06 JB18 PA12                       PA28

Claims (8)

[Claims] 1. An apparatus main body having an opening, opening / closing means reciprocatingly provided in the apparatus main body to open and close the opening, and an image provided in the apparatus main body to form a toner image on a sheet. Forming means, a pair of sheet conveying rotary bodies for conveying the sheet, a rotating body row having a plurality of rotating bodies for transmitting a rotational force of a drive source to the pair of sheet conveying rotary bodies, and an opening / closing operation of the opening / closing means. And a rotation force transmission canceling unit that separates and contacts at least one rotating body of the rotating body row from another rotating body. 2. The image forming apparatus according to claim 1, wherein the rotational force transmission canceling unit moves the at least one rotating body in a direction intersecting a rotation axis of the other rotating body. apparatus. 3. The image forming apparatus according to claim 1, wherein the rotational force transmission canceling unit moves the at least one rotating body in a thrust direction. 4. The rotating shaft of the rotating body of the rotating body row is horizontally arranged, and the rotational force transmission canceling means includes an operating member provided in the opening / closing means and the at least one rotating body in a vertical direction. The image forming apparatus according to claim 1 or 2, further comprising: a movable member that is movably supported by the movable member and that moves the supported rotating body upward by contact with the operating member. 5. The rotating shaft of the rotating body of the rotating body row is horizontally arranged, and the rotational force transmission canceling means is rotated by contact between the operating member provided in the opening / closing means and the operating member. A rotary member, an actuated member that movably supports the at least one rotating body in a vertical direction, the rotary member and the actuated member, and the actuating member abuts the rotary member; The image forming apparatus according to claim 1 or 2, further comprising: a connecting member that causes the operated member to perform an operation of moving the rotating body supported by the operated member upward. 6. The rotating force transmission canceling means moves the at least one rotating body in the thrust direction by the contact between the operating member provided in the opening / closing means and the operating member to separate it from the other rotating body. The image forming apparatus according to claim 1, further comprising an actuated member. 7. The image forming apparatus according to claim 1, wherein the opening / closing unit is a document reading unit capable of horizontally reciprocating to read a document. . 8. The image forming apparatus according to claim 1, wherein the sheet conveying rotating body pair is a transfer rotating body pair that transfers the toner image formed by the image forming unit onto a sheet.