JPH0496078A - Driving device for multicolor image forming device - Google Patents

Abstract

PURPOSE:To prevent deterioration of image quality due to wear of worm gear by supporting a worm gear shaft adjustable by moving it in its axial direction. CONSTITUTION:A bracket 30 is provided with a hole 30a for a bearing 27 and a hole 30b for a fastening screw 40 of a worm supporter 32; a bracket 31 is provided with a semi circular shaped recessed part 31a for engagement of the bearing 27, a screw hole 31b for the fastening screw 40 of the worm supporter 32, and engagement holes 31c and 31d for positioning pins 41 fixed to the supporter 32; and the hole 31c is a slot extended in a direction orthogonally crossed with the worm shaft. The recessed part for engagement 31a is in a position where the vertical relationship is symmetrical against a central line L matched with the axis of the worm shaft 33, and the distance between the centers are 2a against length (a) which is one half of the length of pitch diameter of a worm wheel 34 added to pitch diameter of the worm gear 35. Because the bracket 31 can be attached to the bracket 30 by rotating it 180 deg. and at same precision to the bracket 30, deterioration of image quality due to wear of the worm gear can be prevented.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a driving device for a multicolor image forming apparatus.

114 In a multicolor image forming device, a plurality of image forming units such as photoreceptors and developing devices are arranged in parallel, and the toner images formed by each image forming unit are superimposed and transferred onto the same transfer paper to form a color image. Devices such as this are already known.

In such a multicolor image forming apparatus, providing multiple driving means for multiple image forming sections increases the cost of the apparatus and complicates control. Generally, a worm shaft is orthogonal to a plurality of parallel projecting photoreceptor shafts, and a worm wheel and a worm gear are combined to drive the photoreceptor.

However, when using the above-mentioned worm wheel and worm gear, the part of the worm gear that meshes with the worm wheel is fixed, so only that part will wear out, and the worm gear will wear out. If the value becomes large, there is a problem in that unevenness in drive transmission to the photoreceptor occurs and image quality deteriorates. To solve this problem, at least the worm gear should be replaced when it wears out, but in this case, the problem of increased costs arises.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drive device for a multicolor image forming apparatus that eliminates the above-mentioned conventional problems and can prevent deterioration of image quality due to wear of the worm gear at low cost.

Hands to solve problems The structure of the present invention that achieves the above object is as follows.

A device comprising a plurality of photoreceptors, a worm wheel to which each photoreceptor is fixed, and a worm gear meshing with each worm wheel, each worm gear being fixed to one worm shaft drivingly connected to a drive source. In a drive device for a multicolor image forming apparatus.

The drive device is characterized in that the worm shaft is supported so as to be movable and adjustable in the axial direction.

According to the above configuration, after the second bracket of the support device that supports the worm shaft rotates 180 degrees, the first bracket rotates with the same accuracy.
Since it is attached to a bracket, the worm shaft will move even if each worm gear wears out, and the contact surface of the worm gear to the worm wheel will be reversed, preventing image quality from deteriorating due to worm gear wear and extending the life of the machine. It can be done.

Great Phoenix Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows a color copying machine to which the present invention is applicable.

In FIG. 1, a color copying machine includes a scanner section 1 for reading originals, an image processing section 2 that electrically processes image signals output as digital signals from the scanner section 1, and an image processing section 2 for electrically processing image signals output from the scanner section 1 as digital signals. and a printer section 3 that forms an image on copy paper based on the image recording information of each color.

The scanner part 1 has a lamp 5, such as a fluorescent lamp, for scanning and illuminating the document on the document table 4. The reflected light from the document when illuminated by the fluorescent lamp 5 is reflected by the mirror 6°7.
8 and enters an imaging lens 9. The image light is focused on a dichroic prism 10 by the imaging lens 9, and the image light is focused on a dichroic prism 10, for example, three of red R, green G, and blue B.
The light is split into different wavelengths, and a receiver 11 is used for each wavelength.
, for example, CCDIIR for red, CCDII for green
It is input to CCDIIB for G and blue. Each CCDll
R111G, IIB converts the incident light into a digital signal and outputs it, and the output is subjected to necessary processing in the image processing section 2 to record color information of each color, such as black (hereinafter abbreviated as BK), yellow ( abbreviated as Y), magenta (M
(abbreviated as C), cyan (abbreviated as C), and cyan (abbreviated as C).

Although FIG. 1 shows an example of forming images in four colors, BK, C, M, and Y, it is also possible to form a color image using only three colors. In that case, the number of recording devices can be reduced by one compared to the example shown in FIG.

The signal from the image processing section 2 is input to the printer section 3,
Laser light emitting device of each color [12BK, 12C, 1
Sent to 2M and 12Y.

In the example shown in Figure 1, the printer section includes four sets of recording devices 138,
13C, 13M, and 13Y are arranged side by side. Since each recording device 13 is made of the same constituent members, in order to simplify the explanation, the recording device for C will be explained, and the explanations for other colors will be omitted. Note that for each color, the same parts are given the same reference numerals, and in order to distinguish the configuration of each color, an appendix indicating each color is attached to the reference number.

The recording device 13C has a photoreceptor 14C1, for example, a photoreceptor drum, outside the laser beam emitting device 12C.

A charger 15G, an exposure device including a laser beam emitting device 12C, a developing device 16C, a transfer charger 17C, and the like are attached to the photoreceptor 14C in the same manner as in a known copying apparatus.

Photoreceptor 1 uniformly charged by charger 15G
4C forms a cyan latent image using a laser beam exposure device 12C, and develops it using a developing device 16C to form a developed image. Copy paper supplied by a paper feed roller 18 from a paper feed unit 19, for example, one of two paper feed cassettes, is sent to a transfer belt 21 at the same time that its leading edge is aligned by a registration roller 20. The copy paper conveyed by the transfer belt 21 is transferred to each photoreceptor 1 on which a developed image is formed.
48, 14G, 14M, and 14Y, and the developed image is transferred under the action of the transfer charger 17. The transferred copy paper is fixed by a fixing roller 22 and discharged by a paper discharge roller 23.

By being electrostatically attracted to the transfer belt 21, the copy paper can be conveyed with high precision at the speed of the transfer belt.

FIG. 2 is a plan cross-sectional view schematically showing the driving section of the photoreceptor 14. As shown in FIG.

24C on the photoconductor support shaft 248 of the photoconductor 14;

24M and 24Y are arranged at equal intervals and are rotatably supported by bearings 26 and 27 provided at both ends of the supporter 28. A portion of the bearing 26 is fitted into a drum shaft hole (not shown) formed in the main body side plate 25. On the other hand, a part of the bearing 27 is connected to a worm shaft 33 which will be described in detail later.
The second bracket 31 of the support device 29 that supports the second bracket 31 is engaged with the engagement recess 31a. Further, at the tip of the photoreceptor support shaft 24, a worm wheel 348, 34C, 34M,
34Y is fixed, and 35C, 3
It meshes with 5M and 35Y.

A pulley 3 is connected to one end of the worm shaft 33 through a drive motor 36 and a timing belt 38.
7 is installed. Note that the reference numeral 39 is a collar that suppresses the wobble of the worm shaft 33 in the axial direction.

As shown in FIG.
A first bracket 30 is indirectly fixed to the first bracket 30 via a supporter 28, and a second bracket 31 is detachably fixed to the first bracket 30 with a screw (not shown).
and a worm supporter 32 attached to the second bracket 31 with screws 40).

The first bracket 30 includes a bearing 27 as shown in FIG.
The hole 30a into which the worm supporter 32 is fitted and the hole 30b into which the set screw 40 of the worm supporter 32 is loosely fitted are formed in a sparse manner.

The second bracket 31 includes a shaft and a bearing 2 as shown in FIG.
7 is engaged with, a hole 31b into which the setscrew 40 of the worm supporter 32 is screwed into, and holes 31c, 31d into which the positioning pin 41 fixed to the worm supporter 32 is fitted. is formed, and the hole 31c is formed as a long hole extending in a direction perpendicular to the worm axis.

In this case, the engagement recess 31a has a symmetrical vertical arrangement with respect to a center line that coincides with the axis of the worm shaft 33, and the distance between the centers corresponds to the pitch circle diameter of the worm gear 35. 2 of the length plus the pitch diameter
If the length of 1/2 is a, then it is 2a.

The worm supporter 32 is connected to the bearing 4 as shown in FIG.
A positioning pin 41 for positioning the worm gear 32 on the second bracket 31 is implanted in the worm supporter 32 .

In the drive device with this configuration, the worm gear 35 and the worm wheel 34 mesh at the same location, so the worm gear 3
As previously explained, the photoreceptor 5 may be locally worn compared to the worm wheel 34, and if the wear is severe, uneven rotation of the photoreceptor 14 may occur.

At this time, in the present invention, it is possible to empirically predict the time when rotational unevenness will occur in the photoreceptor 14 due to wear of the worm gear 35, and to deal with it as follows immediately before or when rotational unevenness occurs.

With the above configuration, the worm gear 35 and the worm wheel 34 can be attached without changing the distance between the axes even if the second bracket 31 is rotated 180 degrees with respect to the first bracket 30 and fixed again. That is, the photoreceptor support shaft 248K.

24C, 24M, and 24Y are arranged at equal intervals, and the vertical arrangement of the engagement recesses 31a is symmetrical, so that the second bracket 31 can be rotated and fixed by 180 degrees with respect to the first bracket 30. Even if it is repaired, it can be installed without changing the distance between the axes.

In this manner, after the second bracket 31 is rotated by 180 degrees, the positional relationship between the pulley 37 and the collar 39, which have been reversed, is exchanged. In this case as well, the attachment can be replaced by making the worm shaft 33 an appropriate distance longer than one end of the collar as shown in FIG. This results in
Deterioration of image quality due to wear of the worm gear 35 can be prevented, and the life of the machine can be extended.

Effects According to the above configuration, the present invention provides an angle between the second bracket of the support device that supports the worm shaft and the first bracket by 18°.
After being rotated, it is attached to the first bracket with the same precision, so even if each worm gear wears, the worm shaft will move, and the contact surface of the worm gear to the worm wheel will be reversed, reducing the image quality due to the wear of the worm gear. We were able to prevent the decline in This made it possible to extend the life of the machine.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a color copying machine to which the present invention is applied, and FIG. 2 is a plan sectional view schematically showing the photoreceptor drive section thereof.
FIG. 3 is an enlarged front view showing a part of the photoconductor drive unit, FIG. 4 is a front view of the first bracket, FIG. 5 is a front view of the second bracket, and FIG. 6 is B-B in FIG. 3. FIG. 14...Photoconductor 24...Photoconductor support shaft 25...Body side plate 26.27...Bearing 29...Support device 3o...First bracket 31...Second bracket 31a...・Engagement recess 32... Worm supporter 33... Worm shaft 34... Worm wheel 35... Worm gear Minato 3 Figure 4-

Claims (1)

[Claims] It has a plurality of photoreceptors arranged at equal intervals, a worm wheel fixed to the shaft of each photoreceptor, and a worm gear that meshes with each of the worm wheels, and each of the worm gears is driven by a drive source. In a driving device for a multicolor image forming apparatus that is fixed to one connected worm shaft, a support device that supports the worm shaft is provided, and the support device includes a first drive device that is indirectly fixed to a side plate of the main body. a bracket, a second bracket detachably fixed to the first bracket, and a worm supporter attached to the second bracket to support the worm shaft, and attached to the second bracket to the shaft of the photoreceptor. The driving device, wherein the engagement recess that is engaged with the worm shaft is formed at a symmetrical position with respect to the axis of the worm shaft.