JPH07219410A - Image forming device - Google Patents

Abstract

PURPOSE:To provide a small-sized image forming device causing no impossible start and no defective image and capable of easily interrupting the driving force to a photoreceptor drum and a fixing unit, replacing the photoreceptor drum, and removing the jammed paper at a low cost. CONSTITUTION:This image forming device is provided with a photoreceptor drum 1 having a replaceable image forming unit, a fixing unit 3 nipping and fixing the transfer paper 2 transferred with a toner image on the photoreceptor drum 1, a driving means of a drive system driving at least the photoreceptor drum 1 and the fixing unit 3 with the same drive source, a photoreceptor drum interrupting means interrupting the driving force to the photoreceptor drum 1, a fixing unit interrupting means interrupting the driving force to the fixing unit 3, and a connection releasing means concurrently interrupting the driving force of the photoreceptor drum interrupting means and the fixing unit interrupting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an image forming apparatus, and more particularly, to an image forming apparatus such as a copying machine, a facsimile, a printer or the like which drives at least an image forming unit and a fixing unit with the same drive source. It is about.

[0002]

2. Description of the Related Art In conventional electrophotographic image forming apparatuses such as copying machines, facsimiles, printers, etc., an electrostatic latent image is formed on the surface of a photosensitive drum by the cooperation of a charger and an optical writing unit. An image is formed by transferring a toner image obtained by visualizing the electrostatic latent image with toner or the like from a developing unit onto a transfer paper by a transfer unit and then fixing the toner image by a fixing unit. In such an electrophotographic image forming apparatus, the photosensitive drum, the developing device, etc. are rotationally driven at a constant speed by a DC servo motor, and the scanner device of the optical writing unit and the conveyance of paper etc. can be shifted by a stepping motor. It is well known that the structure is driven to. However, in such a conventional configuration, since it is necessary to use a plurality of motors, there has been a problem that the device is high in cost and large in size.

Further, when the photosensitive drum is replaced when the photosensitive drum is replaced due to deterioration with time or the end of its life, and when the jammed paper is removed, the pair of fixing rollers of the fixing unit is rotated so as to idle. Also, a structure for connecting and disconnecting the driving force of the fixing unit and the like is known (Japanese Patent Laid-Open No. 4-268).
576). However, in the above-mentioned conventional example, at least the connection / disconnection of the driving force to / from the photosensitive drum and the fixing unit is performed by the separate connection / disconnection means. Since the connecting and disconnecting means is used, there is a problem that the device is expensive and large in size. From such a place, set the drive source to 1
It is also known to use a single motor, but when the motor is started, the motor is overloaded and cannot be started, or when the driving force by the clutch is connected or disconnected, a step-out occurs and an image defect occurs. Therefore, since it is necessary to use a motor with a larger rating, the cost of the device becomes high and the size becomes large.

[0004]

The conventional image forming apparatus is not only troublesome in each replacement work for connecting and disconnecting the driving force to the photosensitive drum at the time of replacement and the fixing unit at the time of removing the jammed paper, but not only one Alternatively, even if a plurality of driving sources are used, there is a problem that any driving means becomes expensive and large in size.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to solve such a problem. That is, it is possible to easily connect / disconnect the driving force to / from the photoconductor drum and the fixing unit, easily replace the photoconductor drum, and remove the jammed paper. An object is to provide an image forming apparatus that does not generate.

[0006]

In order to achieve the above-mentioned object, the present invention provides a sheet feeding / conveying unit for conveying a transfer sheet or a document, an image forming unit for forming an image and transferring the image onto the transfer sheet, and a transfer unit. A fixing unit for fixing the formed image on the transfer paper, a paper discharge unit for storing the fixed transfer paper, a reading unit for reading the contents of the original, a driving means for driving these, and a structure for holding and controlling these. In an image forming apparatus including a body and an electrical unit, a replaceable photosensitive drum that constitutes the image forming unit, and a fixing unit that nips and fixes a transfer paper on which a toner image on the photosensitive drum is transferred. A driving means of a driving system for driving at least the photosensitive drum and the fixing unit by the same driving source, and a photosensitive member for connecting / disconnecting the driving force to / from the photosensitive drum. A drum disengaging means, and a fixing unit connecting and disconnecting means for performing disconnection of the driving force to the fixing unit,
The photoconductor drum connecting / disconnecting means and the fixing unit connecting / disconnecting means for connecting / disconnecting the driving force of the fixing unit at the same time are provided, and the driving means drives the driving force of other units when driving the scanner of the reading unit. It is configured to perform disengagement, connection of driving force from the drive source to each unit is performed from a half-clutch state, and the drive means is a drive force of each unit after the drive source is started. The photoconductor drum connecting / disconnecting means connects / disconnects the driving force with a driving gear and a driven gear having the same axis.

[0007]

In the image forming apparatus constructed as described above, at least the replaceable photosensitive drum is driven by the same driving source, and the driving force to the fixing unit that nips the transfer paper when a jam occurs is cut off. The connection and disconnection means are simultaneously applied to avoid a sudden load at the time of starting the drive source, and the driving force is separated by the clutch provided in another unit when the scanner is driven. (EN) It is possible to provide an image forming apparatus in which a replacement work for connecting / disconnecting a driving force to / from the device can be easily performed, the cost is low, the size is small, and a start failure or an image defect does not occur.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a configuration explanatory diagram of an image forming apparatus to which the present invention is applied. The image forming apparatus of the present invention is, for example, a copying machine, a facsimile, a printer, or a facsimile interface (FAX I / F) such as a printer and a scanner. It is an image forming apparatus as a multifunction machine in which the above are integrated. The main configuration of the mechanical portion of the image forming apparatus is an image forming unit that forms a toner image on the surface of the replaceable photosensitive drum 1 and transfers it to the transfer paper 2, and a feeding unit that conveys the transfer paper 2 and an original document. A paper transport unit, a fixing unit 3 that nips and fixes the transfer paper 2 on which the toner image is transferred, a reading unit 9 that reads the content of the original, a paper discharge unit 12 that stores the fixed transfer paper 2, and these. It is composed of a driving unit 5 to be described later, and a structure and an electric unit for holding and controlling these.

FIG. 2 is a block diagram showing an electrical unit of the image forming apparatus of the present invention. This transmission unit is a host 13 as an information processing device which also serves as a user interface, and a peripheral which becomes an input / output portion of the information processing device. Composed of machines. On the peripheral unit side, a simple operation panel 14 for starting and resetting, and an IC card 15 for programs, fonts, and additional memory are provided.

Next, the operation of the electrical system will be described. At the time of image formation, the information processed by the host 13 for image formation printing is sent to the controller 16 in the form of text and bitmap. The controller 16 uses the font information 16a and internal functions to generate an image memory 16b.
The control / write data 16c is generated above. Control above
The write data 16c is sent to the engine control unit 17 including operation instructions from the keyboard 13b and the controller 16 as well. The engine control unit 17 includes a printer unit 18 and an option unit 19 as a mechanism necessary for printing operation.
The transfer paper 2 is conveyed by controlling each of them, and the control / write data 16c from the controller 16 is sequentially processed to form an image on the transfer paper 2.

At the time of image reading, when an image fetch request signal from the host 13 is sent to the engine control unit 17 via the controller 16, the engine control unit 17 causes the scanner unit 10 having a mechanism necessary for the operation of the scanner. A part of the printer unit 18 is controlled to carry a document or the like. The read data 10a from the scanner unit 10 is once buffered by the controller 16 and then sent to the host 13.

During facsimile communication, the telephone number information of the other party is transmitted from the host 13 to the controller 16 when transmitting.
Is sent to the FAX I / F 20 via. At the same time, the controller 16 issues an image acquisition request to the engine control unit 17 to acquire image information from the scanner unit 10.
It is designed to be sent to the FAX I / F 20. The FAX I / F 20 calls a destination using a communication line and compresses image information by MH, MR or the like and sends it out. When the transmitted document is internal information from the host 13 or the storage device 21, the image information is not fetched.

Upon reception, the printer unit 18 immediately determines whether to print an image or store the image in the storage device 21. When the printer unit 18 immediately prints an image, the received information is decompressed by the FAX I / F 20 and sent to the printer unit 18 via the controller 16. When it is stored in the storage device 21, it is sent to the storage device 21 in a compressed state. The received information stored in the storage device 21 can be confirmed on the display 13a of the host 13 via the controller 16, and the image forming printing on the printer unit 18 can be performed at any time as needed. ing.

FIG. 3 is a schematic view showing the transmission path of the driving force of the drive system of the image forming apparatus, and FIGS. 4 and 5 are partially enlarged views of FIG. 3, respectively. At least the drive of the photosensitive drum 1 and the fixing unit 3 are shown. The transmission path of the driving force of the driving means 5 of the drive system in which the same driving source 4 (not shown) is used will be described below.

A drive system reaching the cassette paper feed roller 105 (see FIG. 1) meshes with a gear 101a formed on a stepping motor shaft of a drive source 4 (not shown) to a gear 102a, and a small diameter coaxial gear 102b to a gear 103. hand,
The driving force is transmitted from the gear 104b that is coaxial with the gear 104a to the gear 105b that is coaxial with the gear 105a of the cassette sheet feeding roller 105 (see FIG. 1).
Reference numeral 5b is an electromagnetic clutch or an electromagnetic clutch gear for cassette paper feed roller 106 attached to a clutch 11a of a spring clutch, and meshes with the cassette paper feed roller 10 described above.
5 to the driving force (see FIG. 1).

The drive system leading to the manual feed roller 108 (see FIG. 1) is the same as the drive system leading to the cassette feed roller 105 (see FIG. 1) up to the gear 105a, but the gear 105a is replaced by the gear 107. And the driving force is transmitted from the gear 107 to the gear 108b coaxial with the gear 108a of the manual paper feeding roller 108 (see FIG. 1), and the electromagnetic force for the manual paper feeding roller provided in the clutch 11b of the electromagnetic clutch or the spring clutch is transmitted. It engages with the clutch gear 109 and transmits the driving force to a manual feed roller 108 (not shown).

The drive system up to the scanner timing roller 115 (see FIG. 1) is the same as the drive system up to the gear 103 up to the cassette paper feed roller 105 (see FIG. 1).
The gear 103 meshes with the scanner timing roller electromagnetic clutch gear 110a formed on the clutch 11c as an electromagnetic clutch or a spring clutch, and the driving force is transmitted from the coaxial scanner timing roller electromagnetic clutch gear 110b to the gear 111. Furthermore, the gear 11
1 and the scanner timing roller gear 112 formed on the clutch 11d as an electromagnetic clutch or a spring clutch mesh with each other, and a gear 11 coaxial with the gear 112 is formed.
The driving force is transmitted from 3 to the gear 114 (not integrated with the gear 111) and further to the scanner timing roller gear 115a of the scanner timing roller 115 (see FIG. 1) to rotate the scanner timing roller 115 (see FIG. 1).

When the scanner 10 of the reading unit 9 constituting the driving means 5 is driven, the clutch 1 such as an electromagnetic clutch or a spring clutch is included in the drive system of the other unit.
1 (11a to 11d are provided so that each driving force transmission to them can be separated. Therefore, after starting the stepping motor of the driving source 4,
Since the device portion of each unit with a large load is connected, the slow-up time can be shortened, and a small and inexpensive motor with a large self-starting torque can be used.

The drive system up to the toner supply shaft 122 (see FIG. 1) has a scanner timing roller 115 up to the scanner timing roller electromagnetic clutch gear 110a.
(See FIG. 1), which is the same as the driving system up to and including the coaxial gear 1 of the electromagnetic clutch gear 110a for the scanner timing roller.
10c and the gear 116 mesh with each other, and through a gear 117 and a gear 118 coaxial with the gear 116, a gear 119,
The driving force is transmitted to the gear 121 coaxial with the gear 120 and the toner replenishing shaft gear 122a of the toner replenishing shaft 122 (see FIG. 1) to rotate the toner replenishing shaft 122 (see FIG. 1).

In the drive system leading to the registration roller 128 (see FIG. 1), the gear 101 meshes with the gear 123 and the gear 1
23 to gear 124a, coaxial gear 124b, gear 12
The driving force is transmitted to the gear 5, and meshes with the registration roller electromagnetic clutch gear 126a formed in the registration roller electromagnetic clutch formed in the clutch 11e as the electromagnetic clutch or the spring clutch. Further, the gear 126
The driving force is transmitted from the gear 126b coaxial with a to the gear 127 and the registration roller gear 128a to rotate the registration roller 128 (see FIG. 1).

Developing roller 133 of the developing device (see FIG. 1)
In the drive system up to, the gear 101 meshes with the gear 123,
The driving force is transmitted to the developing roller electromagnetic clutch gear 129a formed on the clutch 11f as the electromagnetic clutch or the spring clutch of the developing device, and to the gear 129b, the gear 130, the gear 131, and the gear 132 which are coaxial with the gear 129a. The driving force is transmitted. The gear 132 is the developing roller gear 1 of the developing roller 133 (see FIG. 1) of the developing device.
33a and the developing roller 133 (see FIG. 1) of the developing device.
Rotate (see). The gear 132 is biased by a spring (not shown) and meshes with the shaft distance. During the print mode operation, the driving force is always transmitted while the process clutch of the developing roller electromagnetic clutch forming the developing roller electromagnetic clutch gear 129a remains ON.

The drive system up to the photosensitive drum 1 (see FIG. 1) is the same as the drive system up to the developing roller electromagnetic clutch gear 129a up to the developing roller 133 (see FIG. 1) of the above-described developing device, and the gear 129a. Gear 129c coaxial with the
The gear 134a and the gear 134 coaxial with the gear 134a
b, the gear 135a, the driving force is transmitted to the coaxial gear 135b which is selectively detachable from the gear 135a, and the photoconductor drum gear 136 formed on the photoconductor drum 1 (see FIG. 1).
Mesh with. The photoconductor drum gear 136 and the gear 135b are positioned by a positioning means (not shown) and mesh with each other while maintaining a good distance between the shafts. Also, the photosensitive drum 1 is replaced with the end of its life, but at that time, it is pulled out in the direction of arrow A in the drawing.

The drive system leading to the fixing roller 3a of the fixing unit 3 (see FIG. 1) and the discharge roller 12a of the discharge unit 12 (see FIG. 1) is a photosensitive drum 1 (see FIG. 1) up to a gear 134b. ) Is the same as the drive system leading to
4b, gear 137a, gear 1 coaxial with gear 137a
The driving force is transmitted to 37b, the gear 138, and the gear 139, meshes with the fixing roller gear 3b integral with the fixing roller 3a, and further passes through the gear 140 to the discharging roller gear 12b formed on the discharging roller 12a. Is transmitted. When operating in print mode, the process clutch is O
The driving force is always transmitted when N is maintained. In addition, as the clutch 11 (11e, 11f) of the process clutch that connects and disconnects the driving force of the paper feeding / discharging unit, the image forming unit, the fixing unit, the paper discharging unit, etc. at the time of printing, a spring clutch is used if there is enough space. The cost can be reduced by using it.

FIG. 6 is a view showing the opening / closing structure of a part of the casing of the image forming apparatus to which the present invention is applied. The release pin 150 locked to the upper frame (not shown) opens the upper frame (not shown). At the time, that is, when the operator or the like replaces the photosensitive drum 1 or removes the jammed transfer sheet 2 (not shown), the operator rotates in the direction of arrow B shown to move from the solid line position shown to the broken line shown. However, the drive release arm 8a is also moved by the operation of the release pin 150 to the position shown by the arrow B in the figure.
It is rotated in the direction to move from the position shown by the solid line to the position shown by the broken line.

At this time, in order to release the bite of the gear and hold the drive release arm 8a in the posture shown by the broken line in the drawing, the drive release arm 8a is rotated by the torsion spring 8b.
Is held in. The engaging portion 8c integrally provided at a predetermined angle from the rotation shaft 8A side of the drive releasing arm 8a engages with the forked portion of the hub 6a of the photosensitive drum connecting / disconnecting means 6 to release the releasing arm. The hub 6 is linked with the opening / closing operation of 8a.
Rotate a by 45 degrees as shown.

FIG. 7 is a view in which a part of a gear group constituting a transmission system is superimposed on the opening / closing mechanism of FIG. 6, and FIG. 8 is shown in FIG.
It is a top view of a part of. 7 and 8, a boss 8d (fixedly supported by a wall W) is inserted and fitted into the hollow cylindrical hub 6a, and the boss 8d is integrally projected from a proper position on the outer peripheral surface of the boss 8d. The protrusion 8e (FIG. 8) thus formed fits into the spiral groove formed on the inner peripheral surface of the hub 6a, and the groove of the hub 6a rotates and moves along the protrusion 8e in the fixed state. The hub 6a moves in the axial direction while rotating. As a result of the axial movement of the hub 6a, the gear 135a is also configured to move in the axial direction. Spring S is gear 13
5a is urged in the direction of meshing with the gear 135b.

The boss portion supporting the gear 135a may be slidably supported in the axial direction with respect to the boss portion supporting the gear 135b. In this case, the hub 6a may be rotated to project the protrusion. The movable boss portion including 8e moves in the axial direction to move the gear 135a in the same direction. In this case, specifically, the groove of the hub 6a is rotated by 45 degrees with the lead 24 mm, so that the boss 8
d moves 3 mm in the axial direction. As a result of the axial movement of the boss 8d, the gear 135a is connected so that the gear 135a axially moves in the same direction.

The position of the hub 6a corresponding to the position of the broken line of the drive releasing arm 8a is the position of the broken line of the hub 6a (see FIG. 6, the position rotated 45 degrees counterclockwise from the solid line position). Then, due to the axial movement of the hub 6a due to the rotation, the gear 135a axially moves in the direction of arrow C in FIG. 8 to reach the position indicated by the broken line. The gear 135a and the gear 135b, which are the photosensitive drum connecting / disconnecting means 6, have concavo-convex teeth (clutch portions) at their opposing portions, and mesh with the gear 135b when the gear 135a is in the solid line position in FIG. When in the position, it is disengaged from the gear 135b.

The gear 135a is moved to the position of the broken line in the direction of the arrow C shown by the rotation of the hub 6a, so that the meshing connection state with the gear 135b is released and the connection / disconnection state of the driving force is changed from the connection state to the disconnection state. Become. Therefore, the gear 135
b can rotate freely without load, and when the photoconductor drum 1 is attached or detached, the gear 135b and the photoconductor drum gear 1
Reference numeral 36 is unloaded and can be disengaged and engaged.
When the drive release arm 8a is at the position indicated by the broken line, the engaging portion 8f integrally formed with the drive release arm 8a is at the position indicated by the broken line, and the link 8g is moved in the direction of arrow D in the figure. Further, the link 8g pushes the arm 8h to move it to the position of the broken line in the direction of arrow E shown in the figure.

Next, the gear 13 of the fixing unit connecting / disconnecting means 7
8 and the gear 139 will be described. The arm 8h rotates about the axes of the gears 137a and 137b, and the gear 1 is rotatably supported by the arm 8h.
38 also moves to the position of the broken line in the direction of arrow E shown in the drawing, and the gear 13
The meshing connection state with 9 is released and the connecting / disconnecting state of the driving force is changed from the contacting state to the disconnecting state. Therefore, the gear 139 can freely rotate with no load, and the gear 139 and the fixing roller gear 3b can be disengaged and meshed with each other with no load. For example, when a jam of the transfer sheet 2 occurs between the pair of fixing rollers 3a (not shown) of the fixing unit 3 (not shown), the fixing roller gear 3b fixed to the fixing roller 3a and the discharge roller 12a fixed to the discharge roller 12a. Since the paper roller gear 12b can freely rotate, the jammed paper of the transfer paper 2 can be easily removed.

The clutch 11 for connecting / disconnecting the driving force of the paper feeding / discharging unit, the image forming unit, the fixing unit, the paper discharging unit, the reading unit, etc. during the printing is
If there is enough space, using a spring clutch will reduce the cost compared to the electromagnetic clutch. Spring 8
i is a biasing force for initially engaging the gear 138 with the gear 139 when the drive release arm 8a is in the position shown by the solid line in the figure, that is, when the gear 138 is located above.

FIG. 9 is a diagram showing the timing of the operation of the drive source and the clutch. During the print mode operation at the time of image formation, the process clutch composed of the electromagnetic clutch or the spring clutch is provided before the stepping motor of the drive source 4 is started. If they are connected, the stepping motor of the drive source 4 will be overloaded and overinertia, so there will be problems such as the need to lengthen the slow-up time and the use of a motor with a large self-starting torque. It was happening.
If the slow-up time is lengthened, the time and frequency (pulse width) at the time of slow-up are controlled by software, and the data is stored in the ROM. There is a problem that consumes a large amount of memory.

Therefore, after the stepping motor as the driving source 4 is started, the driving force is connected by the process clutch as the clutch 11 after a slow-up time has elapsed. Therefore, it is possible to provide an image forming apparatus that includes a drive system that can easily perform the replacement work for connecting / disconnecting the driving force to / from the photoconductor drum and the fixing unit, is low in cost, is small in size, and does not cause a start failure or an image defect. can do.

FIG. 10 is a diagram showing the clutch connection timing corresponding to the output of the drive source.
The connection of 1 is performed in a so-called half-clutch state while gradually increasing the current so as not to apply a sudden load to the stepping motor of the drive source 4. In this embodiment, a simple CR circuit is used, but if the same operation is performed, for example, pulse width modulation (PW
M) A method such as control may be used. Accordingly, the present invention provides an image forming apparatus that is a drive system that enables easy replacement work for connecting and disconnecting the driving force to and from a photoconductor drum and a fixing unit, is inexpensive, is small in size, and does not cause unbootable or image defects. be able to.

[0035]

Since the present invention is configured as described above, the fixing unit for driving at least the replaceable photosensitive drum and removing the transfer sheet nipped when a jam occurs by the same driving source. Since the driving force for driving and is simultaneously connected and disconnected by the decoupling means, a sudden load at the time of starting the driving source is avoided, and the driving force is separated to other units when driving the scanner. ,
It is possible to provide an image forming apparatus that can easily perform the replacement work for connecting and disconnecting the driving force to and from the photoconductor drum and the fixing unit, is low in cost, is small in size, and does not cause a start failure or an image defect. It was

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an electrical system of a schematic configuration of an image forming apparatus showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a main part of an image forming apparatus showing an embodiment of the present invention.

FIG. 4 is a partially enlarged view of FIG.

FIG. 5 is an enlarged view of another part of FIG.

FIG. 6 is a front view illustrating a state of another main part of the image forming apparatus according to the exemplary embodiment of the present invention.

FIG. 7 is a front view illustrating another state of another main part of the image forming apparatus according to the exemplary embodiment of the present invention.

FIG. 8 is a top view of a portion of FIG.

FIG. 9 is a timing diagram illustrating an operation of another main part of the image forming apparatus according to the exemplary embodiment of the present invention.

FIG. 10 is a timing chart illustrating another operation of another main part of the image forming apparatus according to the embodiment of the present invention.

[Explanation of symbols]

1 ... Photosensitive drum, 2 ... Transfer paper, 3 ... Fixing unit, 3a ... Fixing roller, 3b ... Fixing roller gear, 4 ... Drive source, 4a ... Gear, 5 ... drive means, 6 ... photosensitive drum connecting / disconnecting means, 6a ... hub, 7 ... fixing unit connecting / disconnecting means, 8 ... connection releasing means, 8a ... drive releasing arm, 8b ... Springs, 8
c ... Engaging portion, 8d ... Boss, 8e ... Protrusion, 8
f ... Engaging portion, 8g ... Link, 8h ... Arm, 8i ... Spring, 9 ... Reading unit, 10 ...
..Scanner, 10a ... Read data, 11 ...
-Clutch, 11a-f ... Clutch, 12 ... Paper ejection unit, 12a ... Paper ejection roller, 12b ... Paper ejection roller gear, 13 ... Host, 13a ... Display, 13b ...・ Keyboard, 14 ... Operation panel, 15 ... IC card, 16 ... Controller,
16a ... font information, 16b ... image memory, 16c ... control / write data, 17 ... engine control section, 18 ... printer section, 19 ... option section, 20 ... FAX I / F, 21 ... Storage device, 101 ... Gear, 102 ... Gear, 102a ...
b ... Gear, 103 ... Gear, 104a-b ...
Gears, 105 ... cassette paper feed rollers, 105a-b
... Cassette paper feed roller gear, 106 ... Electromagnetic clutch gear for cassette paper feed roller, 107 ... Gear, 1
08 ... Manual feed roller, 108a-b ... Manual feed roller gear, 109 ... Electromagnetic clutch gear for manual feed roller, 110 ... Electromagnetic clutch gear for scanner timing roller, 110a-c ...・ Electromagnetic clutch gear for scanner timing roller, 111 ... Gear, 11
2 ... Electromagnetic clutch gear for scanner timing roller, 113 ... Gear, 114 ... Gear, 115 ...
.Scanner timing roller, 115a ... Scanner timing roller gear, 117 ... Gear, 118 ...
・ Gear, 119 ... Gear, 120 ... Gear, 121
... Gear, 122 ... Toner supply shaft, 122a ...
-Toner supply shaft gear, 123 ... Gear, 124a-b
... Gear, 125 ... Gear, 126 ... Gear, 1
26a ... Electromagnetic clutch gear for registration roller, 12
6b ... Gear, 127 ... Gear, 128 ... Registration roller, 128a ... Registration roller gear, 12
9a ... Electromagnetic clutch gear for developing roller, 129b
.... Gear, 129b ... Gear, 129c ... Gear,
130 ... Gear, 131 ... Gear, 132 ... Gear, 133 ... Developing roller, 133a ... Developing roller gear, 134a-b ... Gear, 135a-b ...
Gears 136 ... Photosensitive drum gears 137a-b.
.... Gear, 138 ... Gear, 139 ... Gear, 14
0 ... Gear, 150 ... Release pin.

Claims (5)

[Claims] 1. A paper feeding / conveying unit for conveying a transfer sheet or an original, an image forming unit for forming an image and transferring the image on the transfer sheet, a fixing unit for fixing the transferred image on the transfer sheet, and a fixing unit. In the image forming apparatus, a paper discharge unit for accommodating the transfer paper, a reading unit for reading the contents of the original, a driving unit for driving them, and a structure and an electrical unit for holding and controlling them are provided. A replaceable photoconductor drum, a fixing unit for nipping and fixing the transfer paper on which the toner image is transferred on the photoconductor drum, and at least the driving of the photoconductor drum and the driving of the fixing unit are the same. Drive means of the drive system driven by the drive source, the photosensitive drum connecting / disconnecting means for connecting / disconnecting the driving force to / from the photosensitive drum, and the disconnection of the driving force to the fixing unit. An image forming apparatus comprising: the fixing unit connecting and disconnecting means for performing, and uncoupling means for performing disconnection of the driving force at the same time of the photosensitive drum disengaging means and the fixing unit connecting and disconnecting means. 2. The image forming apparatus according to claim 1, wherein the driving unit is configured to separate a driving force to another unit when the scanner forming the reading unit is driven. 3. The image forming apparatus according to claim 1, wherein the driving force from the driving source is connected to each unit in a half clutch state. 4. The image forming apparatus according to claim 1, wherein the driving means is configured to connect the driving force of each unit after the driving source is started. 5. The image forming apparatus according to claim 1, wherein the photosensitive drum connecting / disconnecting means connects and disconnects the driving force by a driving gear and a driven gear having the same axis.