JPH05281824A - Color image forming device - Google Patents

Abstract

PURPOSE:To eliminate a defect in a conventional color image forming device and to improve the assembling performance of the color image forming device and the workability of service. CONSTITUTION:Photosensitive body shaft driving parts 261 and 262 consisting of worms 29BK-29Y provided on the same worm shaft 30, worm wheels 28BK-28Y meshing with respective worms provided at the ends of respective photosensitive body shafts 24BK-24Y, and an axially supporting member 33 rotatably supporting the worm shaft 30, and the respective photosensitive body shafts are fixed on the side plate 25 of a device main body as one unit. In order to guarantee the accuracy of exact positional relation between the respective photosensitive bodies and an image forming unit around the photosensitive body, a positioning part for the image forming unit is provided on the axial supporting member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus in which a plurality of photoconductors are formed in one direction so as to form a visible image for superimposing transfer on the same position on a transfer material. ..

[0002]

2. Description of the Related Art A color image forming apparatus having a plurality of photoconductors arranged in one direction to form a visible image for superimposing transfer on the same position of a transfer material is well known in the prior art. .. In such a color image forming apparatus, if rotation unevenness occurs in each photoconductor, color misregistration or density unevenness occurs, which causes deterioration of image quality. For this reason, a photoconductor shaft driving unit that rotationally drives the photoconductor shafts of the plurality of photoconductors on the shaft end side is provided with worms provided on the same worm shaft and at the photoconductor shaft ends. It has already been proposed to have a worm wheel meshing with each worm and to rotationally drive the worm shaft by a motor. In this configuration, in order to prevent the occurrence of the uneven rotation described above, a worm,
It is necessary to tighten the accuracy of the components such as the worm wheel and the mounting position accuracy such as the distance between the shafts.

Further, in the above-mentioned structure, it is already known that the worm wheel mounting angle is adjusted to match the phase of the rotational unevenness between the photoconductors to reduce the color misregistration.

[0004]

In the color image forming apparatus proposed above, first, the shaft supporting member of the photoconductor shaft drive unit is fixed to the main body of the device, then the photoconductor shaft is attached, and then the worm wheel is attached to the photoconductor. Must be fixed to the shaft end.
For this reason, the assembling property is poor, and when the rotation irregularity of the photoconductor occurs due to defective parts or defective assembly, the parts must be replaced, but this workability is disadvantageous.

In the above-described construction in which the phase of rotational unevenness between the photoconductors is adjusted to reduce color misregistration by adjusting the mounting angle of the worm wheel, the phase of rotational unevenness is caused by the eccentricity of the worm wheel and the runout of the shaft. Since it is determined by both, even if one of the photoconductor shaft and the worm wheel is replaced, the phase of the rotation unevenness changes, and readjustment is necessary. In particular, if there is deterioration of parts due to wear over time, replacement of parts by a service person is necessary, but in this case, readjustment of the phase of uneven rotation becomes a very difficult task.

An object of the present invention is to solve the above-mentioned drawbacks in the conventional color image forming apparatus and improve the assembling property and service workability of the color image forming apparatus.

[0007]

According to the present invention, there is provided a worm in which a photoconductor shaft driving unit for rotating and driving each photoconductor shaft of the plurality of photoconductors is provided on the same worm shaft. A worm wheel that is provided at the end of each photoconductor shaft and meshes with each worm, and a shaft support member that rotatably supports the worm shaft and each photoconductor shaft, and a photoconductor shaft drive unit as one unit. It is solved by fixing to the side plate of the device body as.

Further, in order to solve the above-mentioned problems, the present invention provides that a shaft supporting member for rotatably supporting a worm shaft and each photoconductor shaft is driven on the photoconductor shaft on a surface facing a side plate of the apparatus main body. It is proposed to have a positioning part for the part.

Further, according to the present invention, in order to solve the above-mentioned problems, a shaft supporting member for rotatably supporting a worm shaft and each photoconductor shaft is provided on the surface facing the side plate of the apparatus main body of the image forming unit. It is proposed to have a positioning part.

[0010]

A photosensitive member shaft driving unit for rotating and driving the photosensitive member shafts of a plurality of photosensitive members arranged in one direction on the shaft end side is provided with a worm provided on the same worm shaft and each photosensitive member. A worm wheel that is provided at the shaft end and meshes with each of the worms, and a shaft support member that rotatably supports the worm shaft and each of the photoconductor shafts, and the photoconductor shaft drive unit as one unit. Secure to the side plate of. In this case, the shaft support member may be provided with a positioning portion for the photoconductor shaft driving portion and a positioning portion for the image forming unit on the surface facing the side plate of the apparatus body.

[0011]

First, a color image forming apparatus to which the present invention is applied will be described with reference to FIG.

The color image forming apparatus shown in FIG. 1 includes a scanner section 1 for reading a document, an image processing section 2 for electrically processing an image signal output from the scanner section 1 as a digital signal, and an image processing section. 2 and a printer unit 3 for forming an image on a copy sheet based on the image recording information of each color.

The scanner section 1 has a lamp 5 for scanning and illuminating an original on the original table 4, for example, a fluorescent lamp. The reflected light from the document when illuminated by the fluorescent lamp 5 is reflected by the mirrors 6, 7, and 8 and enters the imaging lens 9. The image light passing through the imaging lens 9 reaches the dichroic prism 10, where red R, green G,
It is split into light of three different wavelengths of blue B, and a light receiver for each wavelength, for example, CCD 11R for red, CC for green
The light is incident on the D11G and the blue CCD 11B. Each CC
The outputs from the D11R, 11G, and 11B are converted into digital signals and subjected to necessary processing in the image processing unit 2, and recording color information of each color, for example, black (abbreviated as Bk below), yellow (abbreviated as Y), Magenta (abbreviated as M),
The signals are converted into recording formation signals of cyan (abbreviated as C).

FIG. 1 shows an example of forming four colors of Bk, C, M and Y, but it is also possible to form a color image with only three colors. In that case, the number of recording devices can be reduced by one from the example of FIG.

The signal from the image processing unit 2 is sent to the printer unit 3
To the laser light emitting device 12B of each color
k, 12C, 12M, 12Y.

In the printer section 3, four sets of recording devices 13Bk, 13C, 13M and 13Y are juxtaposed in the illustrated example. Since each recording device 13 is composed of the same constituent members, the recording device for cyan (C) will be described and the other colors will be omitted for simplification of description. For each color, the same parts are designated by the same reference numerals, and in order to distinguish the configuration of each color, the reference numerals are added to indicate the respective colors.

The recording device 13C includes a laser light emitting device 12
C and, for example, a drum-shaped photosensitive member 14C as illustrated. The photoreceptor 14C includes a charging charger 15C, an exposure device using a laser beam emitting device 12C, and a developing device 16C.
C, a transfer charger 17C and the like are additionally provided as in a known copying apparatus.

A latent image of a cyan light image is formed on the photosensitive member 14C uniformly charged by the charging charger 15C by exposure by the laser light emitting device 12C, and this latent image is developed by the developing device 16C and visualized. Is formed. In the other recording devices 13Bk, 13C, 13M, and 13Y, black, magenta, and yellow visible images are similarly formed on the photoconductors 14BK, 14M, and 14Y.

A transfer paper, which is an example of a transfer material, is supplied from the paper supply unit 19 by a paper supply roller 18. For example, the transfer paper supplied from either of the two paper feed cassettes has its leading ends aligned by the registration rollers 20 and is sent to the transfer belt 21 at the same timing. The transfer paper conveyed by the transfer belt 21 is sequentially sent to the photoconductors 14Bk, 14C, 14M, and 14Y on which visible images of different colors are formed,
Under the action of the transfer charger 17, the visible images of the respective colors are superposed and transferred onto the same position on the transfer paper. The transfer paper on which the visible images of the respective colors have been transferred is fixed by the fixing roller 22 and discharged to the outside by the paper discharge roller 23. In this case, the transfer paper is electrostatically attracted to the transfer belt 21, and thus is accurately conveyed at the speed of the transfer belt.

FIG. 2 shows a photoconductor shaft driving unit constructed according to the present invention. In the figure, the main body side plate indicated by reference numeral 25 is
Each support member 26Bk, 26C, 26M, which will be described below,
26Y together with four photoconductor shafts 24Bk, 24C, 24
M and 24Y are rotatably supported on the photoreceptor side via bearings 50. Hereinafter, the subscripts for each color attached to each reference numeral are omitted for convenience.

Each photoconductor 14 is fixedly supported on a shaft 24 via a drum flange 27. A shaft driving unit for rotating and driving each photoconductor shaft 24 is provided on the shaft end side. In the present embodiment, the shaft driving unit is provided with the worms 2 provided on the same worm shaft 30.
9 and each worm 2 fixed to the shaft end of each photoconductor shaft 24.
It consists of a worm wheel 28 that meshes with the 9.
Each worm 29 is rotationally driven by a motor 31 via a timing belt drive unit 32 and a worm shaft 30, and thereby each photoconductor 14 rotates. Reference numeral 35 is a closed oil box.

A shaft support member 33 is arranged so as to be parallel to the main body side plate 25 while maintaining a predetermined distance from the main body side plate 25. Between the shaft support member 33 and the body side plate 25,
A support member 26 provided for each photoconductor is fixedly provided in series, and the shaft support member 33, together with the support member 26,
Through the bearings 51, the shaft portions of the photoconductor shaft 24 on the shaft drive portion side are rotatably supported. Thus, the common shaft support member 33 connects the support members 26.

Further, worm shaft supporting members 34a, 34b, 34c, 34d and 34e are screwed to the shaft supporting member 33 at the positions shown in the drawing, respectively, and these rotatably support the worm shaft 30. The drum flange 27 described above is fixed to the photoconductor shaft 24 also as a thrust stopper for the photoconductor shaft 24. Then, as shown in FIG. 2, the photoconductor shaft drive unit is fixed to the side plate 25 of the main body in a state where the photoconductor shaft drive unit is assembled into a unit shape in advance. In this case, the fixed position is the reference hole 25 in which the positioning projections 261 and 262 provided in the support member 26 are provided in the side plate.
1 and the secondary reference hole 252, it is determined with high accuracy.

By adopting the above-mentioned configuration, the rotation unevenness of the photoconductor shaft is measured by mounting the photoconductor shaft driving unit as a unit on a measuring jig or the like, and the rotation unevenness causing the image quality deterioration is generated. It is possible to confirm the presence or absence and adjust the phase as necessary.

FIG. 3 shows an embodiment in which the worm shaft support member is integrally formed with the shaft support member 33. That is, as indicated by reference numerals 33a, 33b, 33c, 33d, 33e, the worm shaft support member is integrally formed with the shaft support member 33 as an extension support portion.

With this structure, if the stretching support portion is accurately molded, the accuracy of the right angle between the photoconductor shaft 24 and the worm shaft 30 can be increased, and the worm 29 and the worm wheel 28 can be improved. The meshing with the is smooth, and the rotational shake of the photoconductor 14 can be prevented or reduced. This makes it possible to further improve the color image quality.

In the embodiment shown in FIG. 2, an image forming unit such as a developing device and a cleaning device, which is arranged around a photosensitive member (not shown), is different from that of a conventional copying machine by a positioning hole of a side plate of the main body. Similarly, the mounting position is determined. On the other hand, since the position of the photoconductor is unitized as the photoconductor shaft drive unit and is determined by the shaft support member 33, the mounting position accuracy of the support member 26 of the shaft support member 33 must be strict. As a result, it becomes impossible to guarantee good positional relationship accuracy between each photoconductor and the image forming device around the photoconductor, which causes image deterioration.

As a preventive measure against this problem, the embodiment shown in FIG. 4 can be solved. In the figure, a shaft support member 133 is provided between the shaft support plate portion 66 that supports the photoconductor shaft 24 substantially rotatably, and the shaft support plate portion 66 and the main body side plate 25 for each photoconductor shaft. Support part 6 for connecting
7a, 67b, 67c, 67d, and extension support portion 134
a, 134b, 134c, 134d, and 134e are integrally molded and configured. Further, the main body side plate 25 has a shape in which a surface facing the shaft support member 133 is cut out, except for a positioning and fixing portion of the shaft support member 133. And the pivot member 13
3 on the inner surface of the main body side plate 25, for example, developing device positioning reference holes 671BK, 671C, 671M, 6
71Y, reference hole 672B for positioning the cleaning device
K, 672C, 672M, 672Y and others are arranged as needed.

With this configuration, since the positional relationship between the photoconductor and the image forming unit arranged around the photoconductor is determined only by the shaft support member 133, it is easy to guarantee the positional accuracy. Become.

[0030]

According to the first aspect of the present invention, by unitizing the photoconductor shaft drive unit, the presence or absence of uneven rotation, that is, defective parts, before the photoconductor shaft drive unit is assembled to the apparatus main body. It is possible to detect assembly defects and assembly defects at an early stage and improve assembly properties. Further, even when parts need to be replaced due to deterioration or failure of parts due to diameter, the parts can be replaced, so that readjustment is not necessary and service workability is improved.

According to the third aspect of the present invention, the photoconductor shaft drive unit is unitized, and the positioning unit for the image forming unit around the photoconductor is provided on the surface of the photoconductor shaft drive unit facing the body side plate. Therefore, in addition to the effect of the configuration of claim 1, the effect of assuring an accurate positional relationship between the photoconductor and the image forming unit around the photoconductor can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a color image forming apparatus to which the present invention can be applied.

FIG. 2 is a cross-sectional view of a photoconductor shaft drive unit configured as a unit according to the present invention.

FIG. 3 is a sectional view showing a modified example of the present invention.

FIG. 4 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

14BK, 14C, 14M, 14Y Photoconductor 24BK, 24C, 24M, 24Y Photoconductor shaft 25 Main body side plate 26BK, 26C, 26M, 26Y Support member 28BK, 28C, 28M, 28Y Worm wheel 29BK, 29C, 29M, 29Y Worm 30 Worm Shaft 33, 133 Shaft support member 261, 262 Positioning convex portion of photoconductor shaft driving portion 671BK to 671Y, 672BK to 672Y Positioning portion of image forming unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03G 21/00 118

Claims (3)

[Claims] 1. A color image forming apparatus in which a plurality of photoconductors are formed in one direction so as to form a visible image for superimposing transfer on the same position of a transfer material, and the plurality of photoconductors are arranged in one direction. A photoconductor shaft driving section for rotating and driving each photoconductor shaft, a worm provided on the same worm shaft, a worm wheel provided at each photoconductor shaft end and meshing with the worm, the worm shaft and the worm shaft A color image forming apparatus comprising a shaft supporting member for rotatably supporting each photoconductor shaft, and fixing the photoconductor shaft driving unit as one unit to a side plate of the apparatus main body. 2. A shaft supporting member for rotatably supporting the worm shaft and each photoconductor shaft has a positioning portion for the photoconductor shaft drive portion on a surface facing the side plate of the apparatus main body.
The color image forming apparatus according to claim 1. 3. A shaft supporting member that rotatably supports the worm shaft and each photoconductor shaft has a positioning portion for the image forming unit on a surface facing the side plate of the apparatus main body.
The color image forming apparatus according to claim 1.