JPS6312570A - Image former - Google Patents

Abstract

PURPOSE:To prevent image slippage form occurring, by constituting a detector so as to consist of a spherical member capable of rotating at will and a detecting device detecting rotation of the said spherical member, letting this spherical member contact with a moving member, and to make any variation in an optional direction of the said moving member detectable. CONSTITUTION:A speed detector 27 is set up between sensitizer drums 16b and 16c, and a ball 29 of the said detector 27 comes into contact with a web W and it is constituted so as to be dragged together with this web W. And, the said detector 27 detects rotation of the ball 29 with the roller set up in a width direction of the web W, and transmits a conveying speed of the web W and a signal of variations in the width direction of the web W to a control circuit 28 which controls a motor 19 and a stepping motor 26 on the basis of a signal of the said detector 27, adjusting the conveying speed and the cross direction position of the web W. In consequence, stable conveyance of the web W is performable, thus transfer slippage is prevented from occurring.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to an image forming apparatus such as an electrophotographic copying apparatus or a laser beam printer, and more specifically, the present invention relates to an image forming apparatus such as an electrophotographic copying apparatus or a laser beam printer. The present invention relates to the structure of a detection device that detects fluctuations in transfer material conveyance means etc.

(B) Conventional technology Conventionally, an image forming apparatus (hereinafter referred to as a copying machine) equipped with a belt-like moving part The image is first transferred to an intermediate transfer member, and then transferred from the intermediate transfer member to a transfer material.

Also to the applicant. 1-2, using one conventional image forming section (copying section) J→- As an alternative to a copying machine, high-speed 119 drums are arranged side by side and the transfer material is transferred to the belt conveying means, L Color copying machines have been proposed (Japanese Unexamined Patent Publications No. 59-155871,
Publication No. 9-16847, JP-A-59-182+39
j=J Publication, JP-A No. 59-204069)
1. and c4, in the color copying machine described above, when the speed of the belt-shaped moving part +4 changes, the image size in each copying part changes]
was occurring.

Therefore, as shown in FIG. 5, a belt-shaped moving member 1 (
A guiding rib 2 is arranged on the periphery of the conveyor belt 1 in a direction perpendicular to the rotational direction of the conveyor belt 1. A guide groove 7 into which the guide rib 2 fits is provided on the tension roller 6 and the tension roller 6 to prevent the belt 1 from moving laterally. Furthermore, a detection roller 9 that detects the speed of the conveyor belt 1 is arranged in contact with the belt 1, and a rotary encoder 10 that converts the rotation of the roller 9 into an electrical signal is fixed to the shaft of the roller 9. has been done. In addition, the drive roller 3
A motor 11 serving as a power source is connected to il, -C, and a control circuit 12 for controlling the rotation of the motor 11 based on a signal from the encoder 1o is provided. As a result, the rotation direction of the conveyor belt is detected by the roller 9.
Further, the position in the direction perpendicular to the rotational direction is prevented from fluctuating by the guide rib 2, thereby preventing transfer deviation of the image.

←9 Problems to be Solved by the Invention However, since the above-mentioned feed belt without guide ribs has higher rigidity in the part to which the guide ribs are attached than in other parts, g) it is less susceptible to fluctuations and vibrations. It is difficult to absorb, causing unstable running, or the linearity of the guide ribs may become distorted.
The problem was that it did not fit smoothly into the guide groove, causing irregular running. Furthermore, it was difficult to attach the guide ribs to the belt while ensuring the linearity of the ribs.

(b) Second means for solving the problem The present invention aims to solve the above-mentioned problems, and includes a detection device that detects a freely rotatable spherical member and the rotation of the spherical member. The present invention is characterized in that it comprises a detection means, and is configured such that the spherical member is brought into contact with the moving member to detect the movement of the moving member in any direction.

(e) Effect - Based on the configuration described above, when the movable member moves, the spherical member of the detection device that is in contact with the movable member rotates in an arbitrary direction together with the movable member. Then, the rotation of the spherical member, for example, in the moving direction of the moving part is detected by one of the detection means, and the rotation in the direction perpendicular to the moving direction is detected by the other detection means, and these detected values are sent to the control circuit. .

Then, the control circuit corrects the fluctuation of the moving member by controlling the driving means for the moving member based on the detection result.

explain.

In the color electrophotographic copying machine M, as shown in FIG.
b and Pc, and also includes a sheet feeding section (not shown) on the negative side and a fixing section (not shown) on the other side. Part 1
Each of the image forming sections Pa, Pb, and Pc is provided with dedicated exposure means 15a, '1.5b, and 15c, respectively, and dedicated photosensitive drums 16a, 16b around which a Carlson process (not shown) is arranged. , 1.6c are arranged, and furthermore, the photosensitive drums 16a, 1.6b
, ], A dedicated primary charger, a developing device, a cleaning device, and a transfer charger (not shown) are arranged around 6C. MOSHI-C, each image forming section Pa, Pb.

In a manner that penetrates Pc; photosensitive drum I G a, 1
6 b.

An endless feed belt 17 constituting a conveying device 13 that generally feeds the sheet S is stretched under a drive roller 20 driven by a motor 19, a driven roller 21, and a tension roller 22. , Suj relegation 25 is stretched between both ends of the shaft 22a of the tensile roller 22 and both ends of the support member 23, and the spring 25
2. Pull U to give tension to the belt 17. 1. It is configured as follows. Furthermore, in the center of the support member 23, there is a
A tupinog motor 26 is disposed, and the motor 26 rotates the IIN feed belt 17 by swinging the support member 23.
The belt 17 is moved perpendicularly to the direction of rotation by changing the tension at both ends. Further, the conveyor belt 17 carries the sheet 1 fed by the feeding IJ-iso pair.
- S is placed on the first to third image forming sections Pa, Pb.
, Pc are conveyed through the first transfer cotton charger of O'1. L sea urchin composition 11 colors 1. On the other hand, the conveyor belt 17
A belt A1 degree detection device 27 is located on the inner peripheral side of the belt).
17. Further, the device 271 is connected to a control circuit 28, and the control circuit 28 is configured to control the motor 19 and the stepping motor 26 based on the speed detection device 27.

As shown in FIG. 2, the belt speed detection device 27 includes a ball 29 that contacts the conveyor bell l-17 (see FIG. 1) and rotates along with it, and a ball 29 that connects to the core ball 29 and rotates at right angles to each other. The rotary encoders 32 and 33 are connected to the rollers 30 and 31, respectively, and convert the rotation of the rollers 30 and 31 into electrical signals.

Since the present embodiment has the above-described configuration, the color electrophotographic copying apparatus M transfers an original image onto the photosensitive drum 16a using known electrophotographic means such as the primary charger and exposure device of the first image forming section P8. After a latent image of yellow component color is formed, a visible image is formed by a developer having yellow toner in a developing device. Then, remove the sheet from the sheet feeding section.
1・S is transported by a pair of feeding rollers += I・171″
There, the sheet I-S is electrostatically attracted to the conveyor belt 171' by the adsorption charger of TOTO.
Furthermore, the sheet s is conveyed to the first image forming section Pa by the conveyor belt 17 (11), and the yellow toner image is silently transferred thereto (transfer 41), whereby a yellow image is formed on the sheet S.

On the other hand, while the above-mentioned yellow image (ψ is formed on the sheets 1 and S, a latent image of magenta component color is formed in the second image forming section 1). A toner image is formed by toner A1, and the first image forming portion Pa
The sheet S on which the transfer has been completed at 17 is transferred to the second image forming section P b
When the image is conveyed to A1, the magenta image is transferred to a predetermined position on the sheet S.

Thereafter, image formation is performed in the same manner for cyan color, and when the superposition of the three color toner images on Sea 1-SF is completed,
Sheet 1-S is fixed in the C1 fixing section, and a multicolor (full color) image is obtained on Sheet 1-S.

In addition, at this time, the circumferential speed of the conveyor belt 17 and the belt)・1
7 is detected by rollers 30 and 31 that detect the rotation of the ball 29 of the bevel 11 and speed detection device -8=27, respectively, and the rotation of the rollers 30 and 31 is detected by rotary encoders 32 and 33, respectively. It is converted into an electrical signal and sent to the control circuit 28. Then, the control circuit 28
Based on the electric signals sent by the encoders 32 and 33, the rotation of the motor 19 is controlled to correct the conveyance speed of the seat 1-S, and when the widthwise position of the conveyor belt 17 is fluctuating, the stepping The motor 26 is rotated to rotate the support member 23, and the tension roller 22 is further rotated in conjunction with the support member 23. By kneading, the tension at both ends of the conveyor belt 7 changes, and the belt 17 gradually moves in the direction of greater tension while rotating. When the belt 17 moves to a predetermined position, the control circuit 28
In response to this command, the rotation of the stepping motor 26 is canceled and the support member 23 returns to the approximately horizontal home position, but the conveyor belt 17 continues to rotate at the moved position.

In addition, as another embodiment, as shown in FIG.
The visible images formed on 16 b and 16 c-1 are sequentially superimposed and transferred onto a giant belt 17' to form a color image, and the color image is transferred to a sheet by a driven roller 21' and a backup roller 34. +-s' and pressurized or heated to facilitate transfer and re-transfer to sheet 1-8'. At this time, the movement direction of the belt 17 and the fluctuation in the direction perpendicular to the movement direction (also detected by the belt speed detection device 27 and transmitted to the control circuit 28, which controls the motor 19 and the stepping motor 26). to prevent image shift from occurring.

In addition, since the image forming part does not pass through the image forming part, there is no possibility of odor, etc., being generated in the image forming part, and damage to the photosensitive drum and the cleaning device can be avoided. reactor.

Furthermore, another embodiment in which a web W is used for binding 10 and transfer material 17 will be described with reference to FIG.

The color copying machine M does not have a web guide 35a for guiding the web W, and is provided with a wave f support member 35.
A stepping motor 26 for moving the support member 35 in a direction perpendicular to the web feeding direction is disposed on the support member 35, and furthermore, on the downstream side of the support member 35, a photosensitive drum 16a, 16b and 16c are provided.

Furthermore, a driving roller 20'' and a driven roller 2bi connected to the motor 19 are disposed downstream of the drum 16c, and a conveyor belt 1 is disposed between the rollers 20'' and 21''.
7' is stretched. Furthermore, a speed detection device 27 is arranged between the photosensitive drums 1, 6b and 1-6c, and a ball 29'' of the device 27 comes into contact with the web W to prevent the web W from moving.
It is configured to be carried around with the user.

As described above, the device 27 detects the rotation of the ball 29 using the rollers disposed at right angles, and sends the conveyance speed of the web W and the signal of the fluctuation in the width direction of the web W to the control circuit 28. The control circuit 28 controls the motor] 9 and the stepping motor 26 based on the signal from the device 27 to adjust the conveyance speed and widthwise position of the web W. As a result, the web W can be transported stably.
Prevent transfer misalignment.

In addition, as shown in FIGS. 1 and 2, a plurality of transfer parts P
The distance between a, Pb, and Pc is an integral multiple of the circumference of the sphere 29, and is 1 of the circumference of the rollers 30 and 31 that detect the rotation of the nuclear sphere 29! ! ! If it is several times, the nuclear sphere 29 and the roller 30
, 3] due to roundness, eccentricity, or detection errors caused by device assembly accuracy, the same speed fluctuations occur in each image forming device Pn, Pb, and Pc, so that the transferred image Since the images are shifted sequentially, no image shift occurs in the entire image.

(g) As described in detail, in the present invention, the movable member is attached to the detection device 1. Since the structure is configured such that the movement of the moving member in any direction can be detected by contacting the spherical member that can rotate with 3. Be able to detect and correct fluctuations. In addition, since there is no need for guide ribs to restrict the movement of the moving member in the direction perpendicular to the direction of movement, the moving member can absorb torque fluctuations and vibrations, run stably, and prevent image shift. The moving member can also be easily replaced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an image forming apparatus according to the present invention, and FIG.
The figure is a perspective view showing the detection device according to the present invention in detail, FIGS. 3 and 4 are perspective views showing other embodiments, and FIG. 5 is a perspective view showing a conventional example. 16 a , ], 6 b , 16 c =-image carrier, 1.17... moving member, 27... detection device, 29... spherical member, 30, 31, 32,
33.Detection means, M...image forming apparatus.

Claims (8)

[Claims] (1) A transfer unit that transfers the image on the image carrier, a belt-shaped or web-shaped moving member that moves through the transfer unit, and detection that detects a fluctuation value of the moving member to control the moving member. an image forming apparatus comprising: an image forming apparatus, wherein the detection device includes a freely rotatable spherical member and a detection means for detecting rotation of the spherical member, and the spherical member contacts the movable member to detect the movement. An image forming apparatus characterized in that it is configured to be able to detect variations in a member in any direction. (2) The image forming apparatus according to claim 1, wherein the detection device detects the moving direction of the moving member and the position in a direction perpendicular to the moving direction. (3) The image forming apparatus according to claim 1, wherein there is a plurality of detection means for detecting rotation of the spherical member of the detection device. (4) The image forming apparatus according to claim 1, wherein the moving member is a moving member that passes through a plurality of transfer sections. (5) The image forming apparatus according to claim 4, wherein the moving member is a belt-like member and is a conveyance means for conveying a transfer material for transferring the image on the image carrier. (6) The image forming apparatus according to claim 4, wherein the moving member is a belt-like member and is an intermediate transfer member that retransfers the image on the image carrier onto a transfer material. (7) The image forming apparatus according to claim 4, wherein the distance between the plurality of transfer portions is an integral multiple of the circumference of the spherical member. (8) The image forming apparatus according to claim 4, wherein the distance between the plurality of transfer parts is an integral multiple of the circumference of a detection means for detecting rotation of the spherical member.