JPH0462569A - Carrying adjusting method and device for image forming device - Google Patents

Abstract

PURPOSE:To adjust the difference of linear velocity between a carrying device and a fixing device according to whether an unfixed image is rubbed or not by projecting an adjusting member into a carrying path between the carrying device carrying a transfer material to the fixing device and a pair of fixing rollers. CONSTITUTION:In the carrying path 27 between a transfer belt 21 and a pair of the fixing rollers 25 and 26, the adjusting member composed as a lug part member 32 on a shaft capable of rotating 31 is fixed on the upper fixing entrance guide 28. First the lug part member 32 is positioned so as to be protruded toward the lower part compared with the upper entrance guide 28, and copying for adjusting is started. When the linear velocity V2 of a pair of the rollers 25 and 26 is slower than the linear velocity V1 of the transfer belt 21, and the difference of the linear speed exceeds a certain range, a copying sheet P is loosened between them, and the unfixed toner image is rubbed by the lug part member 32. At this time, the driving devices of a pair of the fixing rollers 25 and 26 are finely adjusted, the linear velocity V2 is increased a little, and the fine adjustment of the driving device is carried out, again, in a state where the unfixed toner image is not rubbed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transport adjustment method and apparatus for an image forming apparatus.

BACKGROUND ART In an image forming apparatus that includes a conveyance device that conveys a transfer material from an image transfer section to a fixing device, and a fixing device that includes a pair of fixing rollers that are rotationally driven by a drive device for the conveyance device and a separate drive device, If there is a large difference in linear speed between the conveying device and the fixing device, and the linear speed of the conveying device is faster than that of the fixing device, slack will be formed in the transfer material between the two,
If the slack is large, the unfixed toner image will come into contact with the guide plate, reducing image quality. Additionally, if the linear speed of the transport device is slower than that of the fixing device, the transfer material may be pulled by the fixing device when it is transported across the same device, causing transfer misalignment or wrinkles on the transfer material. .

Therefore, it was necessary to adjust the linear speed difference between the conveying device and the fixing device in advance to a range that does not cause the above-mentioned problems. When performing the above adjustment, which is the object of the invention, it is necessary to adjust the linear speed difference between the conveying device and the fixing device in advance. It is necessary to understand. However, in order to know the linear velocity difference between the two, it is necessary to detect the linear velocity of the conveyance device and the fixing device, and if speed detection means are provided for each, there is a problem in that the cost increases.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a method and apparatus for adjusting the conveyance of an image forming apparatus, which can adjust the linear speed difference between the conveyance device and the fixing device with a simple configuration.

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

(1) In an image forming apparatus having a conveyance device that conveys a transfer material from an image transfer section to a fixing device, and a fixing device equipped with a pair of fixing rollers rotationally driven by a drive device of the conveyance device and a separate active device, In the conveyance adjustment method for adjusting the linear speed difference between the conveyance device and the fixing device, an adjustment member is protruded from above into the conveyance path between the conveyance device and the pair of fixing rollers, A slack is formed in the transfer material within the conveyance path due to the difference in linear speed with the fixing device, and depending on whether or not the unfixed toner image carried on the transfer material is rubbed by the adjustment member due to the slack, the difference between the conveyance device and the fixing device is determined. A conveyance adjustment method characterized by adjusting a difference in slow speed of a device.

(2) In an image forming apparatus having a conveying device that conveys a transfer material from an image transfer section to a fixing device, and a fixing device including a pair of fixing rollers that are rotationally driven by a drive device of the conveying device and a separate active device, In the conveyance adjustment device that adjusts the linear speed difference between the conveyance device and the fixing device, an adjustment member is provided on a conveyance path between the conveyance device and the pair of fixing rollers, and the adjustment member protrudes into the conveyance path from above. A conveyance adjustment device characterized in that it is movable to a position where the conveyance adjustment device is moved.

According to the structure of claim (1), when the unfixed toner image formed on the transfer material is rubbed by the adjustment member, the conveying device and the fixing device have linear speeds equal to or higher than the desired slow speed difference. If it is found that a difference has occurred, and the adjustment member rubs the unfixed toner image, finely adjust one of the moving devices to reduce the linear speed difference slightly, and then adjust to the desired linear speed difference. can.

According to the configuration of claim (2), the yA phasing member is positioned at the protruding position only when adjusting it and is retracted onto the conveyance path when forming one image, and after adjustment, it is possible to prevent the unfixed toner image from being rubbed by the adjusting member. .

Lost 1 piece 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, the 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 that electrically processes image signals output as digital signals from the scanner section 1. and a printer section 3 that forms an image on copy paper as a transfer material 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 mirrors 6, 7, .
8 and enters an imaging lens 9. The image light is focused on the dichroic prism 10 by the imaging lens 9, and for example, three images of red R, green G, and blue B are focused on the dichroic prism 10.
The light is split into different wavelengths, and a receiver 11 is used for each wavelength.
, for example, CCDIIR for red, CCD11 for green
It is input to CCDIIB for G and blue. Each CCD l
I 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 blank (hereinafter abbreviated as Bk), yellow. (abbreviated as Y), magenta (abbreviated as M), 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 devices 12Bk, 12C, 1 for each color
Sent to 2M and 12Y.

In the example shown in the figure, the printer section includes four sets of recording devices 13gk,
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 15C, an exposure device including a laser beam emitting device 12C, a developing device 1.6C, a transfer charger 17C, and the like are attached to the photoreceptor 14C in the same manner as in a known copying apparatus.

The photoreceptor 14C uniformly charged by the 1E electric charger 15C forms a cyan latent image by the laser beam emitting device 12C, and is developed by the 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 sequentially sent to photoreceptors 14Bk, 14C, 14M, and 14Y on which developed images are formed, and the developed images are 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.

In FIG. 2, the copy paper P that has been accurately conveyed to the transfer belt 21 is separated from the transfer belt 21 by the curvature of the bell 1- or an appropriate separating means, and is conveyed to the fixing device 22 while guided by the guide plate 24. . The fixing device 22 includes a pair of fixing rollers including a heat roller 25 and a pressure roller 26, which are driven by a drive device separate from the drive device of the transfer belt 21. It is fixed by being held between the two. At this time, while the rear end side of the copy paper P is conveyed to the transfer belt 21, the front end side thereof is held between the pair of fixing rollers 25 and 26, so that the linear velocity v1 of the transfer belt 21 and the linear velocity of the pair of fixing rollers 25 and 26 It was previously explained that if there is a large difference between the two images and v2, image blurring, image blurring, etc. will occur.

Therefore, it is necessary to adjust the linear speed difference, but the present invention enables such conveyance adjustment with a simple configuration, which will be explained in detail below.

In FIG. 2, a transfer belt 21 and a fixing roller pair 25.
A conveying path 27 between the fixing guides 28 and 26 is formed by the upper and lower fixing guides 28 and 29 of the guide plate 24. As shown in FIG. 3, a shaft 31 rotatably inserted into the side plate 30 of the fixing device 22 is provided on the conveyance path 27, that is, on the upper fixing entrance guide 28, and the shaft 31 is configured as a claw member 32. A plurality of adjusted adjustment members are fixed at appropriate intervals. A knob 33 is fixed to one end of this shaft 31, and the knob 33 is formed with a protrusion 33a that engages with a recess in the side plate 3°, as shown in FIG. It is normally held at the position shown by the chain line in FIG. A spring 34 is fitted to the other end of the shaft 31, and the action of the spring 34 maintains the engagement of the protrusion 33a.

The transport adjustment method of the transport adjustment device having the above structure will be explained.

First, the knob 33 is operated so that the claw member 32 is positioned so as to protrude downward from the master log guide 28. Next, the linear velocity (1) of the transfer belt 21 and the linear velocity (2) of the pair of fixing rollers 25, 26 are set to be approximately the same. At this time, the transfer belt 21 and the fixing device are separate drive sources, and it is unavoidable that linear speed differences occur due to uneven drive transmission, errors in roller diameter, etc.

Now, start copying for adjustment. At this time.

If the linear velocity v2 of the pair of fixing rollers 25 and 26 is slower than the linear velocity v1 of the transfer heald 21 and exceeds a linear velocity difference range, the copy paper P will sag between them, causing the unfixed toner image carried on the copy paper to sag. is rubbed by the claw member 32.

At this time, the drive device of the pair of fixing rollers 25 and 26 is finely adjusted to slightly increase the linear velocity v2, and the fine adjustment of the drive device is completed when the unfixed toner image is no longer rubbed by the claw member 32 again. .

However, if the conveyance speeds of the transfer belt 21 and the fixing device 22 are normally set to be the same, a linear speed difference that is large enough to cause the unfixed toner image to be rubbed occurs, but this is rare, and a copy that is not rubbed is obtained. In this case, the drive device of the fixing device 22 is finely adjusted in the direction of decreasing the linear speed, and if this is repeated and the linear speed of the fixing device exceeds a certain range, the unfixed toner image will be rubbed by the claw member 32. . In this state or by adjusting the linear speed of the fixing device 22 to be slightly faster, the copy paper can be adjusted to a preferable linear speed difference in which a slight slack is formed between the transfer belt 21 and the pair of fixing rollers 25 and 26.

Note that the above adjustment is performed using the longest copyable size paper in the transport direction. Moreover, once the adjustment is completed, the claw member 32
is returned to the position indicated by the chain line in Figure 2. Therefore, the unfixed toner image will not be rubbed by the claw member 32 after adjustment.

FIG. 5 shows another embodiment of the present invention, in which an upper fixing member logite 28 is used as an adjusting member. In this case, the upper fixing entrance guide 28 is mounted so as to be movable from the normal position shown by the solid line in FIG. 5 to the adjustment position shown by the chain line.

Thus, the above adjustment can also be made by moving the upper fixing entrance guide 28 up and down. When making this adjustment.

The upper fixing entrance guide 28 may be raised and lowered manually, but an adjustment motor 34 may also be used as shown in FIG.

In this case, the shaft 35 is fixed to the upper fixing entrance guide 28, and the shaft 35 is supported in a long hole 30a formed in the side plate 3o so as to be movable up and down. A rack plate 36 on which a rack is formed is screwed to this shaft 35, and the rack plate 36 meshes with a gear 38 which is rotationally driven by an adjustment motor 37. Note that 39 is an auxiliary gear, and 40 is a backup roller.

With this configuration, the upper fixing entrance guide 28 is raised and lowered by reversibly driving the adjustment motor 37, thereby making it possible to adjust the linear velocity difference between the transfer belt 21 and the fixing device 22 as follows.

In this adjustment method, the linear velocity (2) of the pair of fixing rollers 25.degree. Then, hold the upper fixing entrance guide 28 at the highest position,
Check whether the unfixed toner image is rubbed by the upper fixing entrance guide 28.

If the unfixed toner image is rubbed, it means that a large slack is formed between the transfer belt 21 and the fixing device W22, and in this case, the linear velocity v2 of the pair of fixing rollers 25 and 26 is slightly increased to remove the unfixed toner image again. Check to see if it rubs. In this way, the linear velocity (2) of the pair of fixing rollers 25 and 26 is gradually increased, and when the unfixed toner image is no longer rubbed, the upper fixing entrance guide 28 is lowered. By repeating this adjustment, the unfixed toner image is rubbed only when the upper fixing entrance guide 28 reaches the lowest position. The linear velocity v2 of the pair of fixing rollers 25 and 26 in this state is a preferable linear velocity difference between the transfer belt 21 and the fixing device 22, and can thus be adjusted to a desired linear velocity difference. After adjustment, upper fixing entrance guide 2
Return 8 to its original highest position.

This adjustment can be performed by the control device shown in FIG. That is, the adjustment motor 37 is driven by inputting the amount of elevation of the upper fixing entrance guide 28, and the rotation speed of the drive motor of the fixing device 22 is finely adjusted by inputting the linear velocity adjustment amount. In this embodiment as well, the linear velocity of the transfer belt 21 is adjusted by vI, and furthermore, the transfer belt 21 and the fixing device 2 are
2 may be finely adjusted.

Effects According to the above configuration, the present invention determines and adjusts the transfer belt and the fixing device to have a desired linear velocity difference depending on whether or not the unfixed toner image formed on the transfer material is rubbed by the adjustment member. It became possible.

In addition, the adjustment member can be moved from the top to the bottom during adjustment and retracted onto the conveyance path during image formation.
The adjustment member does not get in the way during normal image formation.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a color copying machine to which the present invention is applied, FIG. 2 is an explanatory diagram showing an embodiment of the present invention, FIG. 3 is a perspective view showing an example of an adjusting member, and FIG. Its partial sectional view,
FIG. 5 is an explanatory view showing another embodiment of the present invention, FIG. 6 is a perspective view showing an example of an adjusting member, and FIG. 7 is a block diagram of a sub-control device for GA. 21...Transfer belt 22...Fixing device 25.26...Fixing roller pair 28...Upper fixing entrance guide 32...Claw member 4 Figure 5

Claims (2)

[Claims] (1) In an image forming apparatus that includes a conveying device that conveys a transfer material from an image transfer section to a fixing device, and a fixing device that includes a pair of fixing rollers that are rotationally driven by a drive device for the conveying device and a separate drive device, In the conveyance adjustment method for adjusting the linear velocity difference between the conveyance device and the fixing device, an adjustment member is protruded from above into the conveyance path between the conveyance device and the pair of fixing rollers, and A slack is formed in the transfer material within the conveyance path due to the difference in linear speed with the fixing device, and depending on whether or not the unfixed toner image carried on the transfer material is rubbed by the adjustment member due to the slack, the difference between the conveyance device and the fixing device is determined. A conveyance adjustment method characterized by adjusting a linear speed difference between devices. (2) In an image forming apparatus that includes a conveyance device that conveys a transfer material from an image transfer section to a fixing device, and a fixing device that includes a pair of fixing rollers that are rotationally driven by a drive device for the conveyance device and a separate drive device, In the conveyance adjustment device that adjusts the linear velocity difference between the conveyance device and the fixing device, an adjustment member is provided on a conveyance path between the conveyance device and the pair of fixing rollers, and the adjustment member protrudes into the conveyance path from above. A conveyance adjustment device characterized in that it is movable to a position where the conveyance adjustment device is moved.