JP3035142B2 - Image forming device - Google Patents

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 of an electrophotographic type or an electrostatic recording type, and more particularly to a drive source supporting member fixed to a main body frame and a bearing supporting member of a drive transmitting means.

[0002]

2. Description of the Related Art (1) Conventionally, an electrophotographic or electrostatic recording type image forming apparatus includes a document reading driving unit for driving an optical device, a paper feeding and conveying driving unit for feeding and conveying a transfer sheet, and a photosensitive member. , A developing driving unit for driving the developing device, a fixing driving unit for driving the fixing device, and a motor as a driving source for driving these. (2) In the prior art, the drive transmitting means for transmitting the driving force of the motor to the driving means is provided on the frame of the apparatus main body by the number of the driving means, and between the motor and the driving transmitting means, It is connected by multiple chains and belts around the motor. (3) A suction duct for sucking and transporting heat and ozone generated inside and an electric wiring pass through the frame of the apparatus main body. ) Are kept away from the frame.

[0003]

(1) Since the load generated from the drive transmission means varies during the image forming operation, unevenness in the rotation of the motor may occur, and the drive transmission provided on the frame may occur. The means is easily distorted, causing uneven rotation, vibration, and blurring on the image. Also,
Magenta M, Cyan C, Yellow Y, Black BK 4
In the case of a color copying apparatus that forms a full-color image by superimposing color developers, a color shift appears on the image.

FIGS. 5 and 6 show the deformation of the drive transmission means when the belt tension fluctuates. Support plate 31 as a drive source support member or a drive transmission bearing support member
The flange 3 of the support plate 31 is
The support plate 31 is fixed to the main body frame 39 by screwing a small screw 64 through which the flange 1 a comes into contact with the main frame 39. The support plate 31 has a top plate 31b parallel to the main body frame 39, and a shaft 34 is rotatably supported by bearings 32 and 33 fixed to the main body frame 39 and the top plate 31b. A belt 36 is wound around a pulley 35 fixed to an end of a shaft 34 protruding outward from the top plate 31b side, and the belt 36 is also wound around another pulley (not shown). FIG. 5 shows the state before deformation, and FIG. 6 shows the belt tension T.
Is after the deformation when the size becomes larger. Due to the deformation, the main body frame 39 and the support plate 31 are distorted, the shaft 34 falls down, and the bearing 3
The belt 36 rotates in a single contact state with 2, 33, and the belt 36 is worn by being rubbed by the brim of the pulley 35. (2) As described above, the suction duct, the electric wiring, and the like are provided on the main body frame side, and a plurality of chains around the motor and the drive transmission means are provided outside the main body frame.
Since they are connected by a belt, the chain and the belt are located at positions away from the frame, which promotes distortion of the drive transmission means. (3) As a countermeasure for (2), it is possible to separate the suction duct, the electric wiring, and the like from the main body frame 39, and arrange the suction duct, the electric wiring, and the like farther from the main body frame 39 than the chain and the belt, and bring the chain and the belt closer to the main body frame. In addition, at the time of replacing the chain and the belt, the suction duct, the electric wiring, and the like must be removed, which significantly deteriorates the maintainability and the assemblability. (4) In an image forming apparatus provided with a scanning optical device in which the optical system is movable while the platen is fixed, the scanning optical device is provided with a scanning optical device outside the clutch to prevent the forward / reverse electromagnetic friction clutch shaft from falling down due to a load change at the time of reversing. There is a conventional example in which a diameter portion is supported by a stay having the other end fixed to a main body frame. In this case, the shaft is free to move in the direction in which the clutch separates because the body frame is flat, which is not a sufficient solution. In addition, uneven rotation of the motor caused by a change in the inclination of the clutch shaft causes a change in the tension of the chain, and it is impossible to prevent the other drive transmission means from being distorted. (5) The measures to make each drive transmission means independently have a drive source inevitably increase the complexity and size of the device. (6) In the case of color, unless the shift amount of the four colors is suppressed to 50 to 100 μm or less, the image is recognized as a color shift on the image. It is necessary to maintain a constant drive speed. Therefore,
It is essential to prevent distortion of the drive transmission means provided on the main body frame to suppress uneven rotation and vibration.

The present invention relates to a drive source support member and a drive transmission means.
It is an object of the present invention to provide an image forming apparatus in which a bearing supporting member to which a bearing receiving a load is fixed has no distortion.

[0006]

According to a first aspect of the present invention, there is provided an original reading drive unit, a paper feed / conveyance drive unit, a photoconductor drive unit, a development drive unit, a fixing drive unit, and one of the above drive units. or more drive sources, the drive source support members for fixing the driving source to the image forming apparatus main body frame, the driving source driving force of the drive source to transmit to the drive means and the
One or more drive transmission means kicked set between the drive means, in an image forming apparatus having a drive transmission bearing support member, which is fixed a bearing for receiving the load of the drive transmitting means, and the drive source support member, a plurality An image forming apparatus, comprising a stay for supporting and connecting between the drive transmission bearing supporting members on a surface substantially parallel to the image forming apparatus main body frame.

According to a second aspect of the present invention, there is provided an image according to the first aspect, wherein the shaft end of the drive transmission means supported by the bearing is supported by another bearing supported by the stay. It is a forming device.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG. 3 is a schematic sectional view of a color image forming apparatus according to an embodiment of the present invention. The operation will be described with reference to FIG. Platen glass 8
The upper document O is irradiated with the laser beam L onto the photosensitive drum 1 uniformly charged by the primary charger 2 by an exposure device 3 including an optical system 3a and a laser scanner 3b known to those skilled in the art. To form a latent image. Next, the latent image is developed by the developing device 4 in order to make the latent image visible. Since full-color copying normally uses four color toners, the developing device 4 includes a magenta developing device 4M, a cyan developing device 4C, a yellow developing device 4Y, and a black developing device 4BK.
These are mounted on a moving table 26, and the necessary color developing device 4
One of M, 4C, 4Y, and 4BK is moved so as to be arranged below the photosensitive drum 1.

The transfer material is usually transfer paper P, and the transfer paper P is fed out of a paper feed cassette 9 by a paper feed roller 13 or manually fed from a manual feed section 12 to a paper feed roller 1.
The sheet is sent out by the conveying roller 21 arranged next to 3. The transferred transfer paper P is conveyed to the transfer device, that is, the transfer drum 6 by the registration roller 22 in synchronization with the timing of the transfer drum 6. In order to electrostatically attract the transfer paper P to the surface of the transfer drum 6, the transfer paper P is charged by the suction charger 19 while supporting the transfer paper P by the suction roller 20.

The photosensitive drum 1 and the transfer drum 6 are connected and driven by gears, and their outer circumferences are in contact with each other and rotate synchronously at a predetermined process speed without slippage. Therefore, the transfer paper P adsorbed on the surface of the transfer drum 6 is conveyed to a transfer position at a contact point between the photosensitive drum 1 and the transfer drum 6, and an image is transferred by the transfer charger 7. At the transfer position, a pressing sheet 30 for pressing the transfer paper P against the surface of the photosensitive drum 1 is further disposed.

The transfer paper P that has completed the transfer is separated from the transfer drum 6 by the separation claws 14, sent to the fixing device 18 by the transport unit 17, and discharged onto the discharge tray 16 after fixing.

When the transfer paper P is separated from the transfer drum 6, the charge removal device 1 removes residual charge on the surface of the transfer paper P.
0, 11, 29 turn on. Thereafter, the surface of the transfer drum 6 is cleaned by the cleaning device 15.

In order to make a full-color copy, four-color visual images are superimposedly transferred onto the transfer paper P sucked and held on the surface of the transfer drum 6 while keeping the timing. In the photosensitive drum 1, the residual toner is removed by the charger 27 for removing the residual toner after the transfer and the cleaning device 5. After that, the photosensitive drum 1 is uniformly charged again by the primary charger 2.
A latent image is formed by the laser beam L, and this cycle is repeated.

FIG. 1 is a rear view of the embodiment of the present invention, in which a document reading section is removed, in which a rear outer cover of FIG. 3 is removed.
FIG. 2 is a rear view with the stay 40 removed in FIG. FIG. 1 will now be described with reference to FIG. The main body frame 39 is a flat plate or a substantially flat plate and is erected.

In the above, the paper feed roller 13 and the transport roller 21 receive the driving force from the shaft 55 of the paper feed drive unit 47 via the clutch, and move to the positions opposing the photosensitive drum 1 to the developing devices 4M, 4C, 4Y, For example, the developing roller 4a of one developing device 4M of the
The fixing roller 18 a of the fixing device 18 receives a driving force from the shaft 51 of the fixing drive unit 43 by engaging with the shaft 53 of the fixing device 5 and receiving the rotational force.

The support plate 4 of the main motor unit 41
2. The support plate 44 of the fixing drive unit 43, the support plate 46 of the development drive unit 45, and the support plate 48 of the paper feed drive unit 47 are spaced apart from the main body frame 39 and are parallel to the top plates 42a, 44a, 46a, respectively. 48a and the top plate are bent into a crank-shaped cross section from the top plate to the outer flange 42a.
b, 44b, 46b, and 48b, and the small screws 64 are screwed into the main body frame 39 and fixed through the outer flanges. The top plates 42a, 44a, 46a, 4
As shown in FIG. 2, female screws 42c, 44c, 46c, and 48c for attaching the stay 40 of FIG. 1 are provided on 8a. The bearings 32 are fixed to the top plates 42a, 44a, 46a, and 48b, respectively, as in FIG. 5, and the bearings 33 are fixed to the body frame 39 facing these top plates (FIGS. 1, 1). 2 is not shown). That is, each support plate 4
2, 44, 46, 48 and the bearings are top plates 42a, 44a,
Female threads 42c, 44c, 46c, 48 on 46a, 48a
It is the same as FIG. 5 except that c is provided.

The stay 40 is a main motor unit 4
1, a support plate 42 provided as a drive source support member, a support plate 44 of a fixing drive unit 43, and a development drive unit 45.
The small screws 63 are screwed into the female screws 42c, 44c, 46c and 48c of the support plate 46 of the sheet feeding drive unit 47 and the support plate 48 of the paper feed drive unit 47, respectively. Support plates 44, 46, 4
8 is provided as a drive transmitting shaft receiving the support member. Stay 4
With the widest surface 40a of the “0” parallel to the main body frame 39, the section fixed to each of the support plates 42, 43, 46, 48 corresponds to the position of the support plate (height from the main body frame 39). Are bent so as to have a crank shape to provide an outer flange 40b. Also, the outer flange 40
The portion of the surface 40a where no b is provided has its edge bent toward the body frame 39. Therefore, the configuration of the stay 40 is simplified, and if the strength is required, the widest surface 40
It is also easy to add reinforcement such as an aperture to a.

Main motor shaft 49, fixing drive unit 4
The shaft 51 of the third unit, the shaft 53 of the developing drive unit, and the shaft 55 of the paper feed drive unit 47 are supported by bearings 32 and 33, respectively, as in FIG. 5, and the top plates 42a, 44a, 46a and 48 of the respective support plates.
2, a pulley 50 is attached to the main motor shaft 49, a pulley 52 is attached to the shaft 51 of the fixing drive unit 43, and the developing drive unit 4
A pulley 54 is provided on the shaft 53 of the fifth unit, and a sheet feeding drive unit 47 is provided.
A pulley 56 is attached to each of the shafts 55, a belt 57 is wound around the pulleys 50 and 52 in parallel, and a belt 58 is wound around the pulleys 50, 54 and 56 on the inside.
The outside is wound around the idler pulley 59. The photosensitive drum drive unit 60 is driven by a motor 62 dedicated to drum drive via a gear box 61. However, when the photosensitive drum is driven from the main motor unit 41 of the drive source, a chain gear is used. It is driven and the support plate for the bearing of the photosensitive drum is also fixed to the stay.

When a main motor (not shown) is energized, the main motor shaft 49 rotates to rotate the pulley 50 and rotate the pulley 52 via the belt 57 to drive the shaft 51 of the fixing drive unit. The fixing roller 18a rotates, and the pulley 5
4 and 56 rotate to rotate the shaft 55 of the paper feed drive unit and the shaft 53 of the development drive unit to rotate the paper feed roller 13, the transport roller 21, and the developing roller 4a at predetermined timings.

As is apparent from the above configuration, (1) Even if the belt tension fluctuates due to the load fluctuation generated in each drive unit, the deformation of the support plate 31 as shown in FIG. Can be prevented. Therefore, each of the support plates 42, 44, 46, 48 having the same shape as the support plate 31 is provided.
Does not deform. (2) Since the stay 40 is fixed to each of the support plates 42, 44, 46, and 48 at two points, the main motor unit 41, the shafts 49 of the drive units 43, 45, and 47,
Support plates 42, 44, 46, 48 around 51, 53, 55
Also, the distortion of the shafts 49, 51, 53, 55 can be prevented.

Embodiment 2 FIG. 4 shows another embodiment 2 in which a stay 70 corresponding to the stay 40 of the previous embodiment is provided. A hole 71 is formed in the stay 70, and a bearing 73 is provided in the hole 71. The shaft 53 of the developing drive unit is supported by a stay 70 via a bearing 73. As a result, the top plate 46a of the support plate 46 of the developing drive unit 45 and the surface 70a of the stay 70 are spaced from each other, so that the distance between the bearing 73 and the bearing attached to the main body frame 39 is increased. The above effect can be sufficiently exerted even under severe conditions in which the fluctuation width changes due to severe endurance.

In the above description, the same applies to the original reading drive transmitting means which is the driving means of the optical system. The original reading driving means, paper feeding and transport driving means, photosensitive member driving means, developing driving means, fixing driving means, one or more drive source for driving the driving means, driving the drive source and said to transmit the driving source driving source support member fixed to the image forming apparatus main body frame, the driving force of the drive source to the drive means
One or more drive transmission means is provided et the between motion means, in an image forming apparatus having a drive transmission bearing support member, which is fixed a bearing for receiving the load of the drive transmitting means, and the drive source support member, a plurality It is only necessary to have a stay that supports and connects between the drive transmission bearing support members on a surface substantially parallel to the image forming apparatus main body frame.

[0024]

According to the first aspect of the present invention, there is provided a stay for supporting and connecting the drive source support member and the plurality of drive transmission bearing support members on a surface substantially parallel to the frame of the image forming apparatus. Distortion of the drive source support member and the drive transmission bearing support member due to the fluctuation is eliminated, and vibration and rotation unevenness of the drive transmission means can be prevented, so that image blurring can be prevented.

According to a second aspect of the present invention, in the first aspect, the shaft end supported by the bearing of the drive transmission means is supported by another bearing supported by the stay, whereby the shaft is more firmly supported. The above effect can be enhanced.

[Brief description of the drawings]

FIG. 1 is a rear view of a first embodiment of the present invention.

FIG. 2 is a rear view of FIG. 1 with some members removed.

FIG. 3 is a longitudinal sectional view of an image forming apparatus to which the present invention is applied.

FIG. 4 is a rear view of the second embodiment.

FIG. 5 is a plan view of a conventional example.

FIG. 6 is a plan view showing the operation of FIG. 5;

[Explanation of symbols]

 39 Body frame 40, 70 Stay 40a 70a surface 40b Outer flange 41 Main motor unit 42 Support plate 43 Fixing drive unit 44 Support plate 45 Development drive unit 46 Support plate 47 Paper feed drive unit 48 Support plate 49, 51, 53, 55 Axis 50, 52, 54, 56 Pulley 57, 58 Belt

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/00 550 G03G 21/16-21/18 B41J 29/00 B41J 23/02

Claims (2)

(57) [Claims] An original reading drive unit, a paper feed / conveyance drive unit, a photoconductor drive unit, a development drive unit, a fixing drive unit,
One or more driving sources for driving the driving unit, a driving source support member for fixing the driving source to the frame of the image forming apparatus main body, and for transmitting a driving force of the driving source to the driving unit.
To the drive source and one or more drive transmission means is provided et the between the drive means, a bearing for receiving the load of the drive transmitting means
An image forming apparatus having a fixed drive transmission bearing support member, wherein the drive source support member and the plurality of drive transmission bearing support members are supported and connected on a surface substantially parallel to the image forming apparatus main body frame. An image forming apparatus, comprising: 2. The image forming apparatus according to claim 1, wherein a shaft tip supported by said bearing of said drive transmission means is supported by another bearing supported by said stay.