JPH11119583A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extremely easily execute the processing operation of jamming or the like by providing a driving and attaching/detaching mechanism to release the driving connection of a driving transmission gear by gravity when a front frame is opened and to return the driving transmission gear to a driving connection position when it is closed. SOLUTION: When the front frame is opened, a stud 66 provided at the front frame is separated from a lever 65. Since the left side of a rocking bracket 62 where a rocking gear 63 is provided is heavier than a right side by viewing with center at the shaft 61A of a supporting point gear 61, so that the rocking bracket 62 is rotated in a counterclockwise direction by centering the shaft 61A of the supporting point gear 61 by the gravity when the pressing force of the lever 65 does not exist. The meshing of the rocking gear 63 with an input gear 70 is released by the rotation of the rocking bracket 62. Thus, when the meshing of the rocking gear 63 with the input gear 70 is released, the driving connection between a main motor and a pressure roller gear 72 is released. Thus, jamming processing or the like is easily executed.

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, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or the like, a fed sheet of transfer material is conveyed, an image is transferred to the conveyed sheet, fixed, and discharged outside the machine. For transporting the paper, a paper transporting unit having a drive roller body to which the drive is transmitted via a drive transmission gear is provided in the apparatus.

In a heat roller type fixing device having a roller pair of a fixing roller and a pressure roller, a sheet is conveyed and nipped by the roller pair, and at that time, an unfixed toner image is fixed on the sheet by heat and pressure. It can be said that this is a kind of paper conveying means. Further, it is practically impossible to completely eliminate paper deficiencies such as paper jam in the paper conveyance, and therefore, even if a paper jam occurs, various methods and mechanisms for easily processing the paper jam have been proposed.

Since a jam occurs in the fixing device without exception, various methods for removing the paper jammed in the portion have been implemented. In the case of the fixing device, the roller is
2. Description of the Related Art A method of manually rotating a sheet via a knob or the like to feed a sheet out of the apparatus has been widely used. However, in the fixing device, one of the rollers is a driving roller, and the rollers are often meshed with each other by a gear. Therefore, when the driving connection of the driving roller is not released, a large force is required to rotate the knob. However, there is a problem that operability is poor.

[0005] Therefore, in order to facilitate the jam clearance in the fixing device, the driving connection to the driving roller is first released, and as a driving release method, the fixing device is moved to disengage the gears or swing. A method is known in which a moving gear is brought into contact with a spring and a knob is rotated, whereby a pressure angle of the gear acts to separate the swing gear.

[0006]

However, in the method of moving the fixing device and disengaging the gear, the frame of the main body of the apparatus can be divided into upper and lower parts near the fixing part. However, there has been a problem that the mechanical strength of the structure also decreases. There is also a method of moving only the fixing device. However, the mechanism is also complicated and a space for moving the fixing device has to be secured.

In the latter method, in which the swing gear is separated by the pressure angle of the gear, the rotating direction is limited, so that the rotating direction cannot be changed according to the situation of the jammed paper. there were. This problem can be applied to a method of rotating a roller using a one-way clutch or the like.

The present invention solves the above-mentioned conventional problems,
An object of the present invention is to provide an image forming apparatus in which the driving connection of the sheet conveying means can be released by a simple operation, and a processing operation such as a jam can be performed extremely easily.

[0009]

In order to achieve the above object, the present invention relates to an image forming apparatus having a sheet conveying means provided with a drive roller body to which a drive is transmitted via a drive transmission gear. In conjunction with the opening and closing of the opening and closing member provided in the forming apparatus main body, when the opening and closing member is opened, the drive connection of the drive transmission gear is released by its own weight, and when the opening and closing member is closed, the driving is performed. A drive contact / separation mechanism for returning the transmission gear to the drive connection position is provided.

It is to be noted that the present invention provides a drive transmission swinging gear in which the drive contact / separation mechanism can swing between a drive connection position and a drive connection release position below the drive connection position, and the movement of the opening / closing member. It is effective to have a link member for transmitting the drive transmission swing gear through an elastic member.

Further, the present invention is effective when a regulating means for regulating the swing amount of the drive transmission swing gear is provided. Furthermore, the present invention is effective when the restricting means is a side plate of the image forming apparatus main body.

Still further, according to the present invention, the driving roller body is one of rollers in a heat roller type fixing device, and the regulating means is a stay of the fixing device.
It is effective.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic central sectional view showing an example of an image forming apparatus according to the present invention, and this example is a color image forming apparatus.

In FIG. 1, reference numeral 1 denotes a belt-shaped photosensitive member as an image bearing member which is rotated and driven in the direction of arrow A, and is supported by rollers 2 and 3. When the photoreceptor 1 is rotated, the surface thereof is uniformly charged to a predetermined polarity by the charging device 4. A laser beam corresponding to the write information of each color is passed through the scanning optical device 5 from a laser light source (not shown) through optical components such as a polygon mirror 5B rotated by a motor 5A, an fθ lens 5C, and a mirror 5F. To form an electrostatic latent image. This latent image is developed by a black toner developing unit 7 or a cyan developing unit C, a magenta developing unit M, and a yellow developing unit Y provided in a revolver-type multicolor developing device 6, and is visualized. The multicolor developing device 6 is rotated by a driving device (not shown), and a desired developing unit is moved to a predetermined position. The black toner developing unit 7
Is configured to come into contact with and separate from the photoconductor by a cam 45.

Reference numeral 10 denotes an intermediate transfer member,
It is rotatably supported at 1 and 12, and is rotated in the direction of arrow B. The intermediate transfer body 10 receives the toner image on the photosensitive body 1 by the action of the biasing unit 13 at a position where the intermediate transfer body 10 contacts the photosensitive body 1. In the formation of a full-color image, the toner images of black, yellow, magenta, and cyan are transferred to the intermediate transfer member 1.
0, and are collectively transferred to a sheet by a transfer roller. In this case, the paper 17A is configured as a paper feed cassette and stored in the paper feed device 17, and the paper feed roller 18
Are transported by the rotation of the roller, and are transported through the transport roller pair 19. Then, the timing is set by the pair of resist rollers 20, and the toner image on the intermediate transfer body 10 is transferred to a predetermined position on the sheet. Paper 17 after transfer
A passes through a fixing device 50 of a heat roller type, on which a toner image is fixed, and is stacked on a paper discharge stack portion 52 by a paper discharge roller pair 51 with the image surface facing downward in the page order.

When the image is transferred from the photosensitive member to the intermediate transfer member 10,
The toner remaining on the photoconductor 1 is scraped off by a cleaning blade 15A of a cleaning unit. On the other hand, when the toner image is transferred from the intermediate transfer member 10 to the sheet 17A, the toner remaining on the intermediate transfer member 10 is scraped off by the cleaning blade 16A of the cleaning device 16. Cleaning blade 15A of photoconductor 1
Performs the cleaning operation while always in contact with the photoconductor 1,
The operation timing of the cleaning blade 16A of the intermediate transfer member is controlled so that the cleaning blade 16A moves to a position where the cleaning blade 16A comes into contact with the intermediate transfer member and scrapes off the remaining toner after transferring the toner image to the sheet.

After the cleaning process, the light from the neutralization lamp 21 is transferred to the next image forming process with the residual potential on the photosensitive member being normal. In FIG. 2, reference numeral 31 denotes a unitized process cartridge in which the photosensitive member 1, the charging device 4, the intermediate transfer belt 10, the cleaning device 16, the transport guide 30 for forming the paper transport path, and the like are integrally incorporated. It is configured to be exchangeable.

In addition to replacing the process cartridge 31, the multi-color developing unit 6, the black developing unit 7, and the like are also replaced when their lifespan expires. The front frame 8 has a structure that can be opened by rotating around the support shaft 9A (see FIG. 2).

In FIG. 2, the image forming apparatus has an electrical equipment / controller E housed on the left side thereof. Above it, a fan F is provided to exhaust air to prevent the temperature inside the machine from rising excessively. Further, on the right side of FIG. 2, another relatively small-sized sheet feeding device MF is provided. In the figure, MF
Is in a folded state and is used by opening it, but it is not directly related to the present invention, so the description thereof is omitted.

FIG. 3 is a diagram showing a drive transmission system of the fixing device 50 of the image forming apparatus according to the present invention. In FIG.
Reference numeral 66 denotes a stud, which is attached to the front frame 8 as the opening / closing member in FIG. A stud 66 provided on the front frame 8 comes into contact with a right end inclined portion 65B of a lever 65 as a link member rotatably mounted about a fulcrum 65A, and a right end inclined portion 65B of the lever 65 about the fulcrum 65A. Is pushing up. At the left end of the lever 65, a transmission spring 64 as an elastic member is provided,
The swing bracket 62 is connected to the right end via the transmission spring 64. The swing bracket 62 is mounted so as to be swingable about a shaft 61A of the fulcrum gear 61.
The rotational force is urged clockwise via the transmission spring 64 by pushing up the right end inclined portion 65 </ b> B of 5. A swing gear 63 that meshes with the fulcrum gear 61 is rotatably mounted on the swing bracket 62.
Is caused by the rotational force urged by the swing bracket 62.
It is pressed against and engaged with the input gear 70 of the fixing roller pair. The swing gear 63 can swing between a position at which the swing gear 63 meshes with the input gear 70 and a position at which the swing bracket 62 shown in FIG. 4 described below contacts the fixing stay 67 of the fixing device 50.

A main motor (not shown) is drivingly connected to a fixing device gear 60. The fixing device gear 60 is connected to a fulcrum gear 61, a swing gear 63, an input gear 70, a fixing roller gear 71, and a pressure roller gear 72. The gears are sequentially meshed and connected. The rotation of the fixing roller gear 71 and the pressure roller gear 72 causes the pair of rollers of the fixing device 50 to fix and convey the sheet 17A. The pressure roller gear 72 is connected to a knob gear 76 and a knob idler 75 that are rotated by manually rotating the knob 77.

In the image forming apparatus constructed as described above, when the paper 17A is stopped in the fixing device 50 due to a jam or the like, the main motor is drivingly connected to the fixing device gear 60. It is necessary to release the drive connection up to 72. Therefore, in the present invention, when the front frame 8 is first opened, the stud 66 provided on the front frame 8 is separated from the lever 65. When the swing bracket 62 is viewed centering on the shaft 61A of the fulcrum gear 61, the left side provided with the oscillating gear 63 is heavier than the right side. Rotate counterclockwise about the axis 61A of the. By the rotation of the swing bracket 62, the engagement between the swing gear 63 and the input gear 70 is released as shown in FIG.

In this manner, when the engagement between the swing gear 63 and the input gear 70 is released, the drive connection between the main motor and the pressure roller gear 72 is released, and the knob 77
Is manually rotated, the pressure roller gear 72 and the fixing roller gear 71 can be freely rotated by the knob gear 76 and the knob idler 75. Therefore, jam processing and the like can be performed very easily. In addition, since the front frame 8 must be opened in order to perform the jam clearance, it is extremely operable that the drive connection is released in conjunction with the opening of the front frame 8.

The swing bracket 62 rotated by opening the front frame 8 is attached to the fixing stay 6 of the fixing device 50.
The amount of swing of the swing bracket 62 is regulated by the window provided in the swing gear 7.
3 is prevented from being damaged due to contact between the fixing drive gear 60 and the fixing drive gear 60. Note that the swing amount of the swing bracket 62 may be restricted by the side plate of the image forming apparatus. If a component that already exists, such as the fixing stay 67 of this example or the side plate of the image forming apparatus, is used,
The number of parts can be reduced as compared with the case where a dedicated stopper or the like is newly provided.

Further, in the present embodiment, the swing gear 63 can bite into and mesh with the input gear 70 by the action of the pressure angle, so that the transmission spring 64 functions with a small force. . Therefore, the transmission spring 64 may be a small spring, and the lever 65 can be made thin, thus saving space.

When the front frame 8 is closed after the jam clearance or the like is completed, the stud 66 abuts on the right end inclined portion 65B of the lever 65 to push up the right end inclined portion 65B of the lever 65 around the fulcrum 65A. Then, the swing gear 63 returns to the state of meshing with the input gear 70, and the drive from the main motor is transmitted to the pressure roller gear 72.

[0027]

According to the image forming apparatus of the present invention, when the cover is opened due to a paper jam or the like, the drive transmission gear that swings in conjunction with the cover is released by its own weight.
The mechanism is simple and space can be reduced.

According to the image forming apparatus of the second aspect,
Since the elastic member is used between the links for transmitting the opening and closing of the cover to the drive transmission gear, the interference of the cover can be absorbed to prevent the damage, and the tolerance of parts can be absorbed, so that the parts can be easily manufactured.

According to the image forming apparatus of the third aspect,
Since the swinging amount of the oscillating drive transmission gear is regulated, it is possible to prevent contact and damage to nearby components even if there is no mating gear.

According to the image forming apparatus of the fourth and fifth aspects, the number of components can be reduced by using components that already exist.

[Brief description of the drawings]

FIG. 1 is a schematic center sectional view showing an example of an image forming apparatus according to the present invention.

FIG. 2 is an explanatory sectional view showing a state where a front frame of the image forming apparatus shown in FIG. 1 is opened.

FIG. 3 is an explanatory diagram illustrating a drive transmission system of a fixing device of the image forming apparatus according to the present invention.

4 is an explanatory diagram showing a state in which a drive connection of a drive transmission system of the fixing device of FIG. 3 is released.

[Explanation of symbols]

 Reference Signs List 1 photoconductor 50 fixing device 62 swing bracket 63 swing gear 64 transmission spring 65 lever 71 fixing roller gear 72 pressure roller gear

Claims (5)

[Claims] An image forming apparatus having a sheet conveying means provided with a driving roller body to which a drive is transmitted via a drive transmitting gear, wherein the opening and closing member provided in the image forming apparatus main body is opened and closed. A drive contact / separation mechanism is provided for releasing the drive connection of the drive transmission gear by its own weight when the opening / closing member is opened, and returning the drive transmission gear to the drive connection position when the open / close member is closed. An image forming apparatus characterized in that: 2. The image forming apparatus according to claim 1, wherein the drive contact / separation mechanism is capable of swinging between a drive connection position and a drive connection release position below the drive connection position. A link member for transmitting the movement of the opening and closing member to the drive transmission swing gear via an elastic member. 3. The image forming apparatus according to claim 1, further comprising a regulating unit that regulates a swing amount of the drive transmission swing gear. 4. The image forming apparatus according to claim 3, wherein said regulating means is a side plate of a main body of the image forming apparatus. 5. An image forming apparatus according to claim 1, wherein said driving roller body is one of rollers in a heat roller type fixing device, and said regulating means is a stay of said fixing device. An image forming apparatus, comprising: