JPH04371970A - Color electrophotographic device - Google Patents

Abstract

PURPOSE:To measure a meandering quantity for correcting the meandering of an intermediate transfer body belt without providing another meandering detecting unit, on a color image forming device using the intermediate transfer body belt. CONSTITUTION:The position detecting slit 15 of the intermediate transfer body belt 2 provided thereon has a shape so as to measure the meandering quantity of the intermediate transfer body belt 2, as well, and a mechanism detecting the measuring quantity of the intermediate transfer body belt 2 through the use of a signal at the time of detecting a position, and correcting the meandering of the intermediate transfer body belt 2 by the detected meandering quantity. Thus, the meandering of the intermediate transfer body belt 2 can be easily and precisely detected without using another meandering detecting unit, so that a problem that the rising of cost, an attaching space, etc., caused by the installation of the meandering detecting unit, is resolved, and a color electrophotographic device having the improvement of the service life of an intermediate transfer body, color superimposing, and the functions of a device, can be realized.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a color electrophotographic apparatus, and more particularly, electrostatic latent images are developed on a photoreceptor with toners of respective colors, and these toner images are transferred onto an intermediate transfer belt. The present invention relates to a color electrophotographic apparatus that outputs a color image by overlapping the images and transferring them all at once to a sheet of paper.

0002

BACKGROUND OF THE INVENTION In recent years, color electrophotographic devices sequentially form toner images of different colors on an electrostatic carrier such as a photoreceptor.
A color image is output by a method in which toner images of each color are multiple-transferred onto a transfer member. A compact color electrophotographic apparatus has been developed in which an intermediate transfer belt is provided to overlap the toner images of each color once before the toner images of each color are transferred to the transfer member, thereby making effective use of the space within the apparatus. However, in these color electrophotographic apparatuses, the intermediate transfer belt used to make the apparatus more compact has caused a new problem of meandering of the belt.

A color electrophotographic apparatus using a conventional intermediate transfer belt will be described below.

In FIGS. 4, 5, and 6, 1 is a photoreceptor;
2 is an intermediate transfer belt that superimposes the toner images of each color formed on the photoreceptor 1; 3 is a developer that develops the electrostatic latent image on the photoreceptor 1 with toner; and 4 is a belt that converts image data onto the photoreceptor 1. 5 is a sheet of paper; 6 is a transfer device A that transfers the toner image on the photoconductor 1 onto the intermediate transfer belt 2; 8 is a charger that charges the photoreceptor 1; 9 is a cleaning member that cleans the surface of the photoreceptor 1; 10 is a static eliminator that removes the potential of the photoreceptor 1;
11 is a fixing device that fixes the toner to the paper 5; 12 is a paper cassette; 13 is a conveyance device that conveys the paper 5; 14 is a position detector for the intermediate transfer belt 2; and 15 is provided on the intermediate transfer belt 2. A slit for position detection, 16 a roller supporting the intermediate transfer belt 2, 17 a roller 16
18 is a control section that detects the amount of meandering of the intermediate transfer belt 2 and controls the mechanism section 17;
9 is the main body of the electrophotographic apparatus, 50 is a meandering amount detector of the intermediate transfer belt 2, 51 in FIG. 5 is a meandering prevention beat provided on the intermediate transfer belt 2, and 52 is a beat 51 provided on the roller 16 The grooves 21 in FIG.
2 is a spring 2 by changing its position by a motor 20.
Adjustment plates for adjusting the tension of 1 are shown respectively.

The operation of the electrophotographic apparatus configured as described above will be explained below. When an image output command is input to the component 17, the photoreceptor 1 rotates in the direction of arrow X, and the intermediate transfer belt 2 rotates in the direction of arrow Y. When the reference position of the intermediate transfer belt 2 is detected by the slit 15 provided in the intermediate transfer belt 2 passing through the position detector 14, the photoreceptor 1 uniformly charged by the charger 8 is charged. , is irradiated with light corresponding to image data of a predetermined color by the optical section 4, and an electrostatic latent image corresponding to the image data is formed on its surface. The electrostatic latent image formed on the photoreceptor 1 is developed into a toner image by a developing device 3 containing a predetermined toner, and the toner image is transferred onto the intermediate transfer belt 2 by a transfer device A6. After the toner image has been transferred to the intermediate transfer member 2, the photoreceptor 1 is cleaned of residual toner by a cleaning member 9, and its charged state is initialized by a static eliminator 10. This process is repeated a predetermined number of times by detecting the position of the intermediate transfer belt 2. In this way, toner images of each color are sequentially transferred to the intermediate transfer belt 2 each time it is developed, and finally a superimposed toner image of three to four colors including yellow, cyan, magenta, or black is formed. will be formed. Then, the multicolor toner image on the intermediate transfer belt 2 is transferred to the paper 5 conveyed by the conveyance device 13 by a transfer device B7.
The image is transferred all at once and fixed by the fixing device 11, and a color image is output. Therefore, meandering of the intermediate transfer belt 2 not only damages the intermediate transfer belt 2 itself, but also deteriorates the superimposition accuracy of toner images of each color and lowers the function of the apparatus. Therefore, as a method of preventing meandering of the intermediate transfer belt 2, grooves 52 are provided in the beat 51 and the roller 16 on both sides of the intermediate transfer belt 2 shown in FIG. 5 to control the meandering of the intermediate transfer belt 2. Alternatively, as shown in FIG. 6, the meandering state of the intermediate transfer belt 2 is detected by measuring the wobbling of the end of the intermediate transfer belt 2 using the meandering detector 50 of the intermediate transfer belt 2, and based on the data, the meandering state is detected by the control unit 18. By moving the adjustment plate 22 that supports the support roller 16 of the transfer belt 2 to an appropriate position by the motor 20, the tension of the intermediate transfer belt 2 applied to both ends of the support roller 16 is controlled, and the meandering of the intermediate transfer belt 2 is controlled. A method of correcting is used.

[0006]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional configuration, in order to prevent the intermediate transfer belt 2 from meandering, which would reduce the lifespan of the intermediate transfer belt 2 itself, as well as deterioration of image quality, device functions, etc., the intermediate transfer belt Measures to suppress meandering of the intermediate transfer belt 2, such as providing beats 5 on both sides of the intermediate transfer belt 2, are generally taken, but this alone does not provide a complete effect, and measures to detect the amount of meandering and correct it In this case, since the amount of meandering of the intermediate transfer belt 2 is determined by the deflection of the edge of the intermediate transfer belt 2, the accuracy of the edge of the intermediate transfer belt 2 is increased, and a detector is required to detect the edge with even higher accuracy, which increases cost and requires less installation space. There were problems with securing supplies, etc. The present invention has been made to solve these problems, and aims to provide a low-cost, compact color electrophotographic apparatus that extends the life of the intermediate transfer belt itself, improves image quality, and improves the functions of the apparatus.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the color electrophotographic apparatus of the present invention has a position detection slit provided in the intermediate transfer belt in a shape that can also measure the meandering amount of the intermediate transfer belt. A mechanism is provided that detects the amount of meandering of the intermediate transfer belt using a signal at the time of position detection and corrects the meandering of the intermediate transfer belt based on the amount of meandering.

[0008]

[Operation] The color electrophotographic apparatus of the present invention has the above configuration, so that the two sides of the intermediate transfer belt that are in contact with the outside of the image area at right angles are
By providing right triangular slits that are perpendicular or parallel to the traveling direction of the intermediate transfer belt, and detecting the reception time of light passing through these slits with a position detector, the meandering direction of the intermediate transfer belt can be determined. This means that the amount of meandering can be determined.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electrophotographic apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1, 2, and 3, 1 is a photoreceptor;
2 is an intermediate transfer belt that superimposes the toner images of each color formed on the photoreceptor 1; 3 is a developer that develops the electrostatic latent image on the photoreceptor 1 with toner; and 4 is a belt that converts image data onto the photoreceptor 1. 5 is a sheet of paper; 6 is a transfer device A that transfers the toner image on the photoreceptor 1 onto the intermediate transfer belt 2; 7 is an optical unit that forms a corresponding electrostatic latent image; 8 is a charger that charges the photoreceptor 1; 9 is a cleaning member that cleans the surface of the photoreceptor 1; 10 is a static eliminator that initializes the potential of the photoreceptor 1; 11 is a toner. 12 is a paper cassette, 13 is a conveyance device that conveys the paper 5, 14 is a position detector for the intermediate transfer belt, and 15 is an intermediate provided outside the image area of the intermediate transfer belt 2. The slit 15 is a slit for detecting the position of the transfer belt 2, and the shape of the slit 15 is such that one side of the two right-angled sides is perpendicular to the traveling direction of the intermediate transfer belt 2, and the other side is perpendicular to the traveling direction of the intermediate transfer belt 2. It forms a right triangle parallel to the traveling direction and with the oblique side inclined to the traveling direction of the intermediate transfer belt. 16 is a roller that supports the intermediate transfer belt 2; 17 is a mechanism that controls the left and right tension of the roller 16; and 18 is the intermediate transfer belt 2.
A control section 19 is a main body of the electrophotographic apparatus, which detects the amount of meandering of the intermediate transfer belt 2 based on the length of light reception time when detecting the position of the electrophotographic apparatus, and controls the mechanism section 17. FIG. 2A shows the shape of the slit 15 when the position of the intermediate transfer belt 2 provided on the intermediate transfer belt 2 is detected on the upstream side of the intermediate transfer belt 2. Detection of the position of the intermediate transfer belt 2 with no meandering, b with the intermediate transfer belt 2 meandering in the M direction, and c with the intermediate transfer belt 2 meandering in the N direction. These are the light receiving positions of the device 14, and are T1, T2, and T3 in Fig. 2 (b).
are the intermediate transfer belt 2 in states a, b, and c, respectively.
The light reception time of the position detector 14 is shown. 21 in Figure 3
2 represents a motor 20 constituting the mechanism section 17, a spring that applies tension to the roller 16, 22 represents the motor 20, and an adjustment plate that changes the tension of the spring 21, respectively.

The operation of the color electrophotographic apparatus of this embodiment constructed as described above will be explained below.

Since the image forming process is the same as that of the conventional apparatus, the explanation here will be omitted, and the meandering correction of the intermediate transfer belt 2 will be explained below.

A signal serving as a reference for image formation is obtained when a reference slit 15 provided in the intermediate transfer belt 2 crosses a position detector 14 using optical means. Therefore, the shape of the reference slit 15 provided outside the image area of the intermediate transfer belt 2 is as shown in FIGS. It is a right-angled triangle whose other side is parallel to the traveling direction of the intermediate transfer belt 2 and whose hypotenuse is inclined with respect to the traveling direction of the intermediate transfer belt 2. The position of the intermediate transfer belt 2 must be detected to determine whether the side perpendicular to the direction of movement of the intermediate transfer belt 2 should be on the upstream side or the downstream side in the direction of movement of the intermediate transfer belt 2. It is determined whether the slit 15 is taken upstream or downstream. FIG. 2 shows only the case where position detection is performed on the upstream side. The position detector 14 is connected to the intermediate transfer belt 2.
It is provided so as to detect approximately the center of this slit 15 when the belt is not meandering (in the case of a), and when the position detector 14 senses the position of the intermediate transfer belt 2 by this slit 15. The light reception time is T1. Here, when the intermediate transfer belt 2 meanders and the position detector 14 detects the slit position as shown in b, the light reception time is T2.
Therefore, it is shorter than T1. In the case of the slit shape used in the explanation, it can be seen from this time difference that the intermediate transfer belt 2 is meandering in the M direction, and the amount of meandering can be determined from the slope of the oblique side of the slit 15 and the speed of the intermediate transfer belt 2. Desired. Therefore, a meandering correction mechanism 17 is provided in at least one of the support rollers 16, and the adjusting plate 22 is connected to the motor 20 so that the tension on the N side of the intermediate transfer belt 2 is increased by an amount commensurate with the amount of meandering based on the detected data. The meandering of the intermediate transfer belt 2 can be corrected by controlling the intermediate transfer belt 2 by the control unit 18 so as to move the intermediate transfer belt 2 at . Next, when the position detector 14 detects a slit position such as c, the light reception time becomes T3, which is longer than T1. Therefore, it can be seen that the intermediate transfer belt 2 is meandering in the N direction, and the adjustment plate 22 is controlled to be moved by the motor 20 so that the tension on the N side of the intermediate transfer belt 2 is weakened by an amount commensurate with the meandering. It may be controlled by the section 18. That is,
The meandering direction and amount of meandering of the intermediate transfer belt 2 can be detected based on the light reception time when detecting the position of the intermediate transfer belt 2, and there is no need to install a meandering detector 50 as shown in FIG. 4. .

As described above, according to this embodiment, the amount of meandering of the intermediate transfer belt can be detected with high accuracy using the signal at the time of detecting the position of the intermediate transfer belt. It is possible to improve the long life of the intermediate transfer belt itself, the image quality, and the functions of the device without adding any additional components, to reduce costs, and to provide a compact color image device.

[0015]

[Effects of the Invention] As is clear from the above description of the embodiments, the color electrophotographic apparatus of the present invention allows meandering of the intermediate transfer belt to be easily and accurately detected without using a new meandering detector. It is possible to realize a color electrophotographic apparatus which eliminates problems such as increased cost and installation space due to the installation of a meandering detector, and improves the life of the intermediate transfer belt, the overlap of colors, and the functions of the apparatus.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view schematically showing the configuration of a color electrophotographic apparatus according to an embodiment of the present invention.

[Fig. 2] In the explanation of the meandering detection method of the intermediate transfer belt,
(A) is an enlarged cross-sectional view of the slit, and (B) is a diagram showing the light reception time of the position detector at each position of the intermediate transfer belt.

[Fig. 3] A perspective view showing in detail the main parts related to intermediate transfer belt meandering correction.

[Fig. 4] A vertical cross-sectional view schematically showing the configuration of a conventional color electrophotographic apparatus.

[Fig. 5] A perspective view illustrating suppression of meandering due to beats of the intermediate transfer belt.

FIG. 6 is a perspective view illustrating in detail the main parts related to meandering correction of the conventional intermediate transfer belt.

[Explanation of symbols] 1 Photoreceptor 2 Intermediate transfer belt 14 Position detector 15 Slit 16 Roller 17 Mechanism section 18 Control section

Claims (1)

[Claims] 1. An intermediate transfer belt for superimposing toner images of each color formed on a photoreceptor, and a reference position of the intermediate transfer belt for superimposing the toner images of each color on the intermediate transfer belt. an optical position detector for the intermediate transfer belt, two or more support rollers that support the intermediate transfer belt, and a left and right tension of the intermediate transfer belt provided on at least one of the support rollers; and a control section that controls the mechanism, and the intermediate transfer belt is provided with a slit outside the image area for detection by the position detector, and the slit is shaped at right angles. One side of the two contacting sides is perpendicular to the traveling direction of the intermediate transfer belt, the other side is parallel to the traveling direction of the intermediate transfer belt, and the oblique side is perpendicular to the traveling direction of the intermediate transfer belt. The position detector has an inclined right triangle shape, and the position detector simultaneously detects the reference position and meandering state of the intermediate transfer belt using the slit, and uses the detected meandering state to detect the meandering state of the intermediate transfer belt. A color electrophotographic device that performs correction.