JPH10307447A - Electrophotographic color recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a color image where color slurring is eliminated by reducing the phase shift of an intermediate transfer body between respective colors caused by the fluctuation of a rotational load without reducing a recording speed and also to obtain an excellent color image without banding. SOLUTION: The rotation of a driving motor 40 is at first transmitted to an intermediate transfer body 16 through a first driving transmitting means 41 using a driving transmitting belt with teeth 45. Then, it is transmitted to a photoreceptor 11 through a second driving transmitting means 42 using a driving transmitting belt with the teeth 50. Then, one driving motor 40 drives the intermediate transfer body (6) together with the photoreceptor 11 and a color image is formed on the intermediate transfer body 16 by successively transferring monochromatic images formed on the photoreceptor 11 so that color recording is executed on paper by performing the transfer of the color image as a package.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention can be applied to an electrophotographic recording apparatus for offices, homes, etc., such as a laser printer, a laser copying machine, a laser facsimile, or a combination thereof. For details, form a monochromatic image on the photoconductor,
The present invention relates to an electrophotographic color recording apparatus that sequentially transfers the single-color images to form a color image on an intermediate transfer body, and collectively transfers the color images to perform color recording on paper.

[0002]

2. Description of the Related Art Conventionally, in this type of electrophotographic color recording apparatus, a color shift may occur due to a phase shift between respective colors, and one of the causes is the rotation of a photosensitive member and an intermediate transfer member. There was uneven speed. Causes of uneven rotation speed include uneven rotation speed of the drive motor itself, manufacturing accuracy error of drive transmission means such as uneven pitch of gears and eccentricity of pitch circles, and fluctuation of rotational load applied to the photoconductor and the intermediate transfer member. It was

[0003] Therefore, among the conventional ones, as shown in Japanese Patent Application Laid-Open No. 8-137180, a drive transmission means for driving a photosensitive member and an intermediate transfer member by one drive motor and transmitting rotation to them. There is a configuration in which each of the gears has the same shape.

Further, as shown in Japanese Patent Application Laid-Open No. 8-227200, there is a structure in which a toothed belt is used as the drive transmission means.

[0005]

Certainly, in such a conventional color recording apparatus, when a color image of an intermediate transfer member is collectively transferred and color recording is finished on a sheet and the next recording is started, a constant value is obtained. The effect of can be exhibited.

However, in that case, the recording speed is reduced, so that it is actually necessary to start the next recording before the end of the color recording. Then, there is a problem that the fluctuation of the rotational load on the intermediate transfer member during the transfer of the composite image or the cleaning of the intermediate transfer member affects the next image formation, causing a color shift in the color image on the intermediate transfer member. In particular, this is a problem when the drive transmission path from the drive motor to the intermediate transfer member is long.

Therefore, an object of the present invention is to obtain a color image free from color misregistration by reducing the phase deviation between the respective colors of the intermediate transfer member, which is caused by the fluctuation of the rotational load, without decreasing the recording speed, and without banding. It is to obtain a good color image.

[0008]

According to the first aspect of the present invention, for example, a belt-shaped photosensitive member 11 is driven by a single drive motor 40, as described in the following embodiments. Is driven to form a single-color image of, for example, yellow, magenta, and cyan on the photoreceptor 11, and sequentially transfers the single-color images to the intermediate transfer member 16. In an electrophotographic color recording apparatus for forming a composite color image composed of a plurality of color images and collectively transferring the color images and performing color recording on paper P, the driving motor 40
First rotation is transmitted to the intermediate transfer body 16 via the first drive transmission means 41, and then the second drive transmission means 4
2, and at least one drive transmission belt 50 is used as the second drive transmission means 42.

According to the first aspect of the present invention,
At the time of recording, the rotation of the drive motor 40 is first transmitted to the intermediate transfer body 16 via the first drive transmission means 41, and then via the second drive transmission means 42 using at least one drive transmission belt 50. It is transmitted to the photoconductor 11.

According to a second aspect of the present invention, in the electrophotographic color recording apparatus according to the first aspect, for example, as described in the following illustrated embodiment, the first
Drive transmission belt 45 as a drive transmission means 41 of
Characterized by using

In the invention described in claim 2,
At the time of recording, the rotation of the drive motor 40 is transmitted to the intermediate transfer body 16 via first drive transmission means 41 using a toothed drive transmission belt 45.

According to a third aspect of the present invention, in the electrophotographic color recording apparatus according to the first aspect, for example, as described in the following embodiment shown in the drawings,
One process cartridge 35 is configured by using the intermediate transfer member 16 and the intermediate transfer member 16 and is detachably provided to the apparatus main body 10, while the first and second drive transmission means 41.
42 is provided on the apparatus main body 10 side.

In the invention according to claim 3,
When the photoconductor 11 or the intermediate transfer member 16 reaches the end of its life,
The first and second drive transmission means 41 and 42 are left in the apparatus main body 10 as they are, and only the process cartridge 35 is taken out and replaced with a new one.

According to a fourth aspect of the present invention, in the electrophotographic color recording apparatus according to the third aspect, for example, the process cartridge 35 and the first and second process cartridges 35 as described in the following embodiments shown in the drawings. The second drive transmission means 41 and 42 are connected via couplings 46 and 52, respectively.

In the invention described in claim 4,
When the process cartridge 35 is mounted, first and second drive transmission means 41.4 provided on the apparatus main body 10 side
2 are connected via couplings 46 and 52, respectively.

According to a fifth aspect of the present invention, there is provided the electrophotographic color recording apparatus according to the first aspect, wherein the color image of the intermediate transfer body 16 is formed on a sheet as described in the following embodiment. Either one or both of the transfer roller 21a of the composite image transfer device 21 for collective transfer to P and the cleaning member 22a of the intermediate transfer member cleaning device 22 for removing the residual developer of the intermediate transfer member 16 after the collective transfer, It is characterized in that the intermediate transfer member 16 is pressed against the outer periphery of a driving roller 16a around which an intermediate transfer belt 16c is wound.

Further, in the invention according to claim 5,
During recording, the transfer roller 21a of the composite image transfer device 21 and the cleaning member 22 of the intermediate transfer member cleaning device 22
The driving roller 1 that applies the pressing force of either or both of a to the intermediate transfer belt 16c of the intermediate transfer body 16.
Receive on the outer circumference of 6a.

According to a sixth aspect of the present invention, in the electrophotographic color recording apparatus according to the first aspect, for example, as described in the following embodiment, the photosensitive member 11 is connected to a driving roller 11a. A cleaning member 17a of a photoconductor cleaning device 17 configured to span a photoconductor belt 11c between driven rollers 11b and removes residual developer on the photoconductor belt 11c after image transfer is provided on the outer periphery of the drive roller 11a. It is characterized by being pressed against.

In the invention according to claim 6,
At the time of recording, the pressing force of the cleaning member 17a of the photoconductor cleaning device 17 is received on the outer periphery of the drive roller 11a of the photoconductor 11 that hangs over the photoconductor belt 11c.

According to a seventh aspect of the present invention, in the electrophotographic color recording apparatus according to the first aspect, for example, as described in the following embodiment, the photosensitive member 11 is connected to a driving roller 11a. The photoreceptor belt 11c is stretched between driven rollers 11b.
An image writing position A on the drive roller 11a is provided on the outer periphery of the driving roller 11a.

According to the seventh aspect of the present invention,
At the time of recording, an image is written at an image writing position A on the outer periphery of the drive roller 11a of the photoconductor 11.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall schematic configuration diagram of an internal mechanism in a color laser printer according to the present invention.

Reference numeral 10 in the drawing denotes a printer apparatus main body. The photoreceptor 11 is provided in the printer body 10 at a position slightly closer to the front in the center of the outer case 12 (rightward in the figure). As shown in FIG. 2, the photoconductor 11 includes an endless photoconductor belt 11c which is stretched between a driving roller 11a and a driven roller 11b.

Around the photoreceptor 11, a multicolor developing device 14, a black developing device 15, an intermediate transfer member are arranged in order from a charging device 13 provided thereunder in a conveying direction a indicated by an arrow in FIG. 16. Photoconductor cleaning device 1
7. It has a static eliminator 18. Further, a laser writing device 19 is provided below the multicolor developing device 14.

The multicolor developing device 14 has a support frame 14c supported by a central shaft 14b in a cylindrical case 14a. A developing device containing a yellow developer, a developing device containing a magenta developer, and a developing device containing a cyan developer are attached to the support frame 14c.
The support frame 14c is centered on the center axis 14b.
By rotating the developing roller 63, the developing roller 63, which will be described later, of each developing device can be sequentially brought into contact with the photosensitive belt 11c.

As can be seen from FIG. 2, each of the developing devices is provided with a screw-shaped first developer conveying member 60, a second developer conveying member 61, a supply roller 62, and a developing roller 63 in parallel with each other.

As shown in FIG. 3, a fan-shaped developer accommodating portion 65 for each color is provided at one end of such a multi-color developing device 14 so as to be combined with the whole circular shape. The developer storage portions 65 are provided outside the portions 65, respectively.
The developer cartridge 66 for replenishing the developer is detachably attached.

As shown in FIG. 2, the black developing device 15
Are placed in the developing case 15a.
5c, a supply roller 15d, a developing roller 15e, and the like. The spring is normally urged toward a cam (not shown) provided on the left side of the drawing, while the cam is rotated during use to bring the developing roller 15e into contact with the photosensitive belt 11c as appropriate.

The intermediate transfer body 16 has an endless intermediate transfer belt 16c between a driving roller 16a and a driven roller 16b.
And a part thereof comes into contact with the photoreceptor belt 11c. The photoconductor image transfer device 16 is located inside the contact position.
d is provided. Then, the transfer roller 21a of the composite image transfer device 21 is pressed against the outer periphery of the drive roller 16a from the right side, and the cleaning member 22a of the intermediate transfer member cleaning device 22 is pressed against the left side.

The transfer roller 21a and the cleaning member 22a are movable by a contacting / separating mechanism (not shown), and appropriately contact and separate from the intermediate transfer belt 16c during recording.

The photosensitive member cleaning device 17 presses the cleaning member 17a against the outer periphery of the drive roller 11a of the photosensitive member 11. Then, the cleaning member 17a
Then, the residual developer on the photoreceptor belt 11c after the image transfer is removed and collected and stored inside.

The laser writing device 19 irradiates the laser beam L on the basis of the writing information, and performs writing at the image writing position A provided on the outer periphery of the driving roller 11a.
An electrostatic latent image is formed on 1c.

The printer main body 10 further includes a fixing device 24 above the black developing device 15, a paper discharge roller pair 25 on the left side of the fixing device 24, and a printer main body 10 on the left side. A paper discharge stack unit 26 is provided above. The fixing device 24 includes a fixing roller 24a having a built-in heater, a pressure roller 24b pressed against the fixing roller 24a, and an oil supply mechanism 24c for applying oil to the peripheral surface of the fixing roller 24a.

Further, although not shown, the printer main body 10 also has, for example, an electric device on the left side of the multicolor developing device 14, and a ventilation fan on the upper side thereof. Further, at the bottom, a paper feed cassette 28 containing paper P is stored.
Can be freely installed and removed.

When recording is performed using the illustrated printer, the paper P in the paper feed cassette 28 is fed by rotating the paper feed roller 29, and is conveyed through the paper feed path 31 by the conveyance roller pair 30. It stops against the registration roller pair 32.

At the same time, the photosensitive belt 11c is moved in the conveying direction a.
The intermediate transfer belt 16c is conveyed in the conveying direction b. Then, the surface of the photoconductor belt 11c is uniformly charged by the charging device 13 as the photoconductor belt 11c is conveyed, and then the laser beam L is irradiated by the laser writing device 19 based on the writing information of the first color to cause the photoconductor belt 11c to be charged. An electrostatic latent image of the first color is formed on top.

Then, at the position of the multi-color developing device 14, the first developing device moved to the developing position in contact with the photoreceptor belt 11c adheres the first color developer to develop the electrostatic latent image.
The visible image is transferred to the intermediate transfer belt 1 by the photoconductor image transfer device 16d.
6c once. After the image transfer, the residual developer of the first color remaining on the photoconductor belt 11c is removed by the cleaning member 17a of the photoconductor cleaning device 17.

Thereafter, when images of the second and third colors are formed, laser writing is similarly performed based on the respective writing information to form respective electrostatic latent images, and the second and third images are formed. To develop the electrostatic latent images by transferring the visible images onto the intermediate transfer belts 16c, and after transferring the images, the electrostatic latent images are transferred onto the photosensitive belts 11c. To clean.

When a black developer is used, similarly, laser writing is performed based on the writing information to form an electrostatic latent image, and the developing roller 15e of the black developing device 15 is brought into contact with the photosensitive belt 11c. Then, the electrostatic latent image is developed, the visible image is transferred onto the intermediate transfer belt 16c, and after the image is transferred, the photosensitive belt 11c is cleaned.

After each cleaning of the photoconductor belt 11c, the surface of the photoconductor belt 11c is neutralized by the static eliminator 18 to prepare for the next writing.

After forming the composite color image on the intermediate transfer belt 16c as described above, the composite image transfer device 2
The transfer roller 21a and the cleaning member 22a of the intermediate transfer body cleaning device 22 are moved to come into contact with the intermediate transfer belt 16c, while the registration roller pair 32 moves the paper P between the transfer roller 21a and the intermediate transfer belt 16c. Transport to Then, the intermediate transfer belt 1
The composite color image on 6c is transferred to the lower surface of the paper P by the transfer roller 21a.

After the image transfer, the sheet P is conveyed between the fixing roller 24a and the pressure roller 24b through the conveying path 33 with its recording surface facing down. Then, heat and pressure are applied between the rollers to fix the transferred image, and after the fixing, the pair of paper discharge rollers 25 discharges the transferred image from the paper discharge port 34 onto the paper discharge stack unit 26 and stacks them sequentially.

On the other hand, after the image is transferred onto the intermediate transfer belt 16c, the developer remaining on the intermediate transfer belt 16c is cleaned by the cleaning member 22a of the intermediate transfer body cleaning device 22. The developer is conveyed toward the photoconductor cleaning device 17.

In the illustrated printer, the photosensitive member 11 and the intermediate transfer member 16 are integrally supported together with the charging device 13, the intermediate transfer member cleaning device 22, and the registration roller pair 32 by the frame 35a. The cartridge 35 can be attached to and detached from the printer body 10. The process cartridge 3
In 5, a photoconductor cleaning device 17 is provided so as to be replaceable so that the collected developer can be discarded as it is.

In the present invention, as shown in FIG. 4, the rotation of one drive motor 40 is transmitted to the intermediate transfer body 16 via the first drive transmission means 41, and then the second drive transmission means 42 To the photoreceptor 11 via the

The first drive transmission means 41 extends a toothed first drive transmission belt 45 between the motor pulley 43 and the first intermediate pulley 44, and the first drive transmission belt 45 is coaxial with the first intermediate pulley 44. The convex portion side 46a of the coupling 46 is provided and configured. The concave side 46b of the first coupling 46 is
As shown in FIG. 4, the driving roller 16 a of the intermediate transfer member 16
At the end of the shaft.

On the other hand, the second drive transmission means 42 is provided between a second intermediate pulley 47 provided coaxially with the first intermediate pulley 44 and a third intermediate pulley 49 provided coaxially with the first drive transmission gear 48. A second toothed drive transmission belt 50 is wound around the first toothed drive transmission gear 48 and the second power transmission gear 51
And the second drive transmission gear 51 is provided with a convex side 52a of the second coupling 52 coaxially therewith. The concave side 52b of the second coupling 52 is provided at the shaft end of the drive roller 11a of the photoconductor 11 as shown in FIG.

When mounting the process cartridge 35, the convex side 46 a is provided on the concave side 46 b of the first coupling 46, and the concave side 52 a of the second coupling 52 is provided.
The convex portion side 52a is put in b, and is connected to the first and second drive transmission means 41, 42 provided on the printer device main body 10 side via the respective couplings 46, 52.

As a result, the photosensitive member 11 is driven by one drive motor 40 and the intermediate transfer member 16 is driven to form a single-color image on the photosensitive member 11 as described above. A color image is formed on the body 16, the color image is collectively transferred, and color recording is performed on the paper P.

In the illustrated example, the first drive transmission gear 4
8 and a second drive transmission gear 51 are provided, and the rotation direction in which they are meshed with each other and transmitted to the photoconductor 11 is reversed. However, for example, as shown in FIG. The first drive transmission gear 48 and the second drive transmission gear 51 may be omitted by meshing the first drive transmission gear 48 with the third intermediate pulley 49 to reverse the rotational direction transmitted to the photoconductor 11.

[0051]

Therefore, according to the first aspect of the present invention, during recording, the rotation of the drive motor is first transmitted to the intermediate transfer member via the first drive transmission means, and then the second drive transmission means. , The drive transmission path from the drive motor to the intermediate transfer body is shortened without increasing the number of parts, and the phase shift between the colors of the intermediate transfer body caused by fluctuations in the rotational load is reduced. A color image without color shift can be obtained. Further, since at least one drive transmission belt is used for the second drive transmission means, it is possible to obtain a good color image without banding by eliminating the unevenness of the rotation speed with the drive transmission belt.

According to the second aspect of the present invention, a toothed drive transmission belt is also used as the first drive transmission means, and during recording, the rotation of the drive motor is intermediately transferred through the toothed drive transmission belt. Since it is transmitted to the body, it is possible to obtain a good color image with less banding by eliminating the uneven rotation speed by the same drive transmission belt.

According to the third aspect of the present invention,
One process cartridge is configured by using the photoconductor and the intermediate transfer member, and when the photoconductor or the intermediate transfer member reaches the end of its life, the process cartridge is taken out and replaced by a new one, so that the replacement workability thereof is improved. be able to. At the time of the replacement work, the first and second drive transmission means, which are made and finely adjusted with high precision, are left in the main body of the apparatus and only the process cartridge is replaced with a new one. Can be reduced.

According to the fourth aspect of the invention, since the process cartridge and the first and second drive transmission means are connected to each other through the couplings, the coupling causes the axial deviation between the two. In addition, it is possible to absorb the eccentricity of the two or the deviation of the shaft angle, and to prevent the occurrence of unevenness in the rotational speed. This allows the process cartridge and the first
And allow a margin in the positional accuracy of the second drive transmission means,
Manufacturing costs can be reduced.

According to the invention described in claim 5, at the time of recording,
Since the pressing force of one or both of the transfer roller and the cleaning member is received on the outer periphery of the drive roller over which the belt of the intermediate transfer member is applied, the intermediate transfer member is subjected to rotation load fluctuations caused by the transfer roller and the cleaning member. It is possible to prevent the belt from expanding and contracting, and to obtain a color image with less color shift.

According to the invention described in claim 6, at the time of recording,
Since the pressing force of the cleaning member is received on the outer periphery of the drive roller over which the photoreceptor belt is stretched, it is possible to prevent the photoreceptor belt from expanding and contracting on the basis of fluctuations in the rotational load caused by the cleaning member, and to achieve a color image without further color shift. Can be obtained.

According to the invention of claim 7, at the time of recording,
Since the image is written on the outer circumference of the drive roller of the photoconductor, it is not affected by the expansion and contraction of the photoconductor belt due to uneven rotation speed.
A good color image with less banding can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of an internal mechanism in a color laser printer according to the present invention.

FIG. 2 is a partially enlarged view around the developing device.

FIG. 3 is a perspective view of a multicolor developing device used in the color laser printer.

FIG. 4 is a perspective view showing a drive transmission system used in the color laser printer.

FIG. 5 is a perspective view showing another example of the drive transmission system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Printer apparatus main body 11 Photoconductor 11a Drive roller 11b Follower roller 11c Photoconductor belt 16 Intermediate transfer member 16a Drive roller 17 Photoconductor cleaning device 17a Cleaning member 21 Synthetic image transfer device 21a Transfer roller 22 Intermediate transfer member cleaning device 22a Cleaning member 35 Process cartridge 40 Drive motor 41 First drive transmission means 42 Second drive transmission means 45 First drive transmission belt with teeth 46 Coupling 50 Second drive transmission belt with teeth 52 Coupling A Image writing position P Paper

Claims (7)

[Claims] A single drive motor drives a photoreceptor and drives an intermediate transfer member using a belt to form a single-color image on the photoreceptor, and sequentially transfers the single-color image to the intermediate transfer member. In an electrophotographic color recording apparatus that forms a color image and collectively transfers the color image to perform color recording on paper, the first rotation of the driving motor is performed first.
And then to the photoreceptor via a second drive transmission means, and using at least one drive transmission belt as the second drive transmission means. An electrophotographic color recording device. 2. The electrophotographic color recording apparatus according to claim 1, wherein a drive transmission belt with teeth is used as the first drive transmission means. 3. A process cartridge is formed by using the photosensitive member and the intermediate transfer member and is detachably attached to the apparatus main body, while the first and second drive transmission means are provided in the apparatus main body. The electrophotographic color recording apparatus according to claim 1, which is provided on the side. 4. The electrophotographic color recording apparatus according to claim 3, wherein the process cartridge and the first and second drive transmission means are connected to each other through a coupling. 5. A transfer roller of a composite image transfer device for collectively transferring a color image of the intermediate transfer member onto a sheet, and a cleaning member of an intermediate transfer member cleaning device for removing residual developer of the intermediate transfer member after the batch transfer. 2. The electrophotographic color recording apparatus according to claim 1, wherein one or both of the above are pressed against the outer periphery of a drive roller that hangs the belt of the intermediate transfer member. 6. A cleaning member of a photoreceptor cleaning device, wherein the photoreceptor is constituted by a photoreceptor belt being stretched between a driving roller and a driven roller, and a developer remaining on the photoreceptor belt after image transfer is removed. 2. The electrophotographic color recording apparatus according to claim 1, wherein the color is pressed against the outer periphery of the drive roller. 7. The photosensitive member is constructed by arranging a photosensitive belt between a driving roller and a driven roller, and an image writing position on the photosensitive belt is provided on an outer circumference of the driving roller. 2. The electrophotographic color recording device according to 1.