JP2001343877A - Image forming method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that decreases transfer displacement of a rear end. SOLUTION: The device is composed of a table 521 and a control part 500. In the table 521, relations between data on concerning at least the size of a transfer material P, a tray on which the transfer materials P are stored, temperature, humidity, or the front and rear of the transfer material and rotating speed of at least a registration roller or a fixing roller (registration roller in Fig.1) are recorded. The control part 500 fetches data concerning at least the size of the transfer material P, the tray an which the transfer materials P are stored, the temperature, the humidity, or the front and back of the transfer material P, then refers to the table 521 to determine the revolving speed of at least the registration roller or the fixing roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of transferring a transfer material to an image carrier having a toner image formed thereon using a registration roller, transferring the toner image onto the transfer material, and transferring the toner image. The present invention relates to an image forming method and apparatus for fixing the transferred toner image onto the transfer material by heating and pressing the transferred transfer material with a fixing roller.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, in particular, in an apparatus for transporting a transfer material in a vertical direction which is almost vertical, the deflection of the transfer material in a transport path is caused by image quality, especially image shift (this is referred to as "transfer shift"). ").

[0003] This is a transfer method in which the adhesion of the transfer material at the transfer point is not so good, such as electrostatic transfer, as compared with a transfer method in which the adhesion of the transfer material at the transfer point is good, such as roller transfer or belt transfer. Was particularly remarkable.

[0004]

Generally, the deflection of the transfer material in the transport path is caused by the difference between the rotation speed of the fixing roller and the rotation speed of the registration roller immediately before the transfer point of the image carrier. Deflection occurs when the rotation speed of the fixing roller is relatively low.

If the amount of deflection is too large, the deflection is released immediately after the trailing edge of the transfer material has passed through the registration roller, and the transfer material moves backward with respect to the image carrier at the transfer point. In addition, a rear-end transfer deviation such as compression in the traveling direction of the transfer material occurs on the image.

Further, in order to prevent the transfer material from wrinkling, the fixing roller generally has a difference in roller diameter between a central portion and an end portion (an inverted crown having a narrower central portion). Therefore, the rotational speed of the central portion of the fixing roller is lower.

For this reason, when a transfer material having a small width is passed, the speed difference between the fixing roller and the registration roller increases, so that the amount of flexure also increases, and the rear end transfer deviation easily occurs.

Further, when the width of the transfer material is the same, the longer the length of the transfer material in the transport direction is, the larger the total amount of deflection is, which is disadvantageous for the rear end transfer deviation. Further, even in the case of transfer materials of the same size, if the tray used is different, the transfer speed of the transfer material by the registration roller may be different. This is because the transfer material is pulled by the roller on the upstream side of the registration roller, so that the transfer speed of the transfer material at the registration roller portion is lower than the rotation speed of the registration roller (the transfer material slides on the registration roller).
It is caused by a phenomenon.

Therefore, even if transfer materials of the same size are used, if the trays are different, the amount of deflection of the transfer material in the conveyance path is different, so that a difference occurs in the degree of occurrence of rear end transfer deviation. Further, the rear end transfer deviation also differs depending on the transfer current value. Generally, an image forming apparatus controls a transfer current value according to humidity and temperature of an environment in which the image forming apparatus is installed. When the transfer current is large, the degree of adhesion of the transfer material to the image carrier at the transfer point increases, and when it is small, the degree of adhesion decreases.

Therefore, the degree of occurrence of the rear-end transfer deviation varies depending on the humidity and temperature. Furthermore, when the automatic double-sided image forming function is provided,
The curls are often different. Since the curl affects the amount of deflection of the transfer material in the transport path, there is a difference in the degree of occurrence of rear-end transfer deviation between the front surface and the back surface.

As described above, depending on the size of the transfer material, the tray in which the transfer material is stored, the temperature, the humidity, and the conditions of the front and back sides of the transfer material, the degree of occurrence of the rear-end transfer misalignment and the presence or absence of the occurrence may differ. I will.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an image forming apparatus in which the degree of rear end transfer deviation is reduced.

[0013]

According to a first aspect of the present invention, a transfer material is conveyed to an image carrier having a toner image formed thereon using a registration roller, and the toner image is transferred to the image carrier. An image forming method for fixing the transferred toner image onto the transfer material by heating and pressing the transfer material onto which the toner image has been transferred by transferring and transferring the toner image with a fixing roller, the size of the transfer material, A tray in which the transfer material is accommodated, a temperature, a humidity, and at least one of front and back conditions of the transfer material, the registration roller,
An image forming method, wherein a rotation speed of at least one of the fixing rollers is determined.

According to a second aspect of the present invention, a transfer material is conveyed to an image carrier having a toner image formed thereon using a registration roller, and the toner image is transferred onto the transfer material, and the toner image is transferred. In an image forming apparatus for fixing the transferred toner image onto the transfer material by heating and pressing the transferred transfer material with a fixing roller, the size of the transfer material, the tray in which the transfer material is stored, and the temperature A table in which a relationship between at least one data of the front and back of the transfer material and the rotation speed of at least one of the registration roller and the fixing roller is recorded, and a size of the transfer material, At least one of the tray in which the transfer material is stored, the temperature, the humidity, and the front and back of the transfer material
An image forming apparatus comprising: a control unit that fetches two data, refers to the table, and determines a rotation speed of at least one of the registration roller and the fixing roller.

The registration roller may be provided in accordance with at least one of a size of the transfer material, a tray accommodating the transfer material, temperature, humidity, and front and back of the transfer material.
By controlling the rotation speed of at least one of the fixing rollers, the degree of rear-end transfer deviation is reduced.

The image carrier and the fixing roller are driven by the same drive source, and the rotational speed of the registration roller is changed so that the ratio of the transport direction of the image transfer material to the direction perpendicular to the transport direction (longitudinal magnification ratio) is increased. In an adjustable image forming apparatus, it is desirable to change the rotation speed of the registration roller as in the third aspect of the invention.

In this case, if the rotational speed of the registration roller must be largely changed in order to eliminate the occurrence of the transfer deviation at the rear end, the aspect ratio is greatly changed. Therefore, in preparation for a case where an exact aspect ratio is required, as in the invention according to claim 4, the size of the transfer material, the tray in which the transfer material is stored, the temperature, the humidity, the transfer material It is desirable to have a mode for changing the rotation speed of the registration roller and a mode for not changing the rotation speed in accordance with at least one condition of the front and back.

On the other hand, when the image bearing member and the fixing roller are driven by different driving sources, the invention is described as follows.
It is desirable to change the rotation speed of the fixing roller. In this case, an image having an accurate aspect ratio can be obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment in which the image forming apparatus of the present invention is applied to a copying machine will be described with reference to the drawings.

(Overall Configuration) First, the overall configuration of the image forming apparatus according to the embodiment will be described with reference to FIG. In the figure, an image forming apparatus (copying apparatus) 1 is an automatic document feeder.
(Commonly known as ADF) A, a document image reading unit B for reading an image of a document conveyed by the automatic document feeder A, an image control unit C for processing the read document image, and according to the data after image processing, A writing unit D including a writing unit for writing on an image carrier 10 composed of a photosensitive drum; a charging electrode 14 around the image carrier 10 and a developing means 16 composed of a magnetic brush type developing device; a transfer electrode 18; An image forming unit E including an image forming unit such as an electrode 20 and a cleaning unit 21; a storage unit F for trays 22 and 24 for storing the transfer material P; and a transfer material for forming images on both sides of the transfer material P It has a reversing mechanism X for reversing P and the like.

The automatic document feeder A includes a document table 26
And a document transport processing unit 28 including a roller group including the roller R1 and a switching unit for appropriately switching a document moving path.

The original image reading section B is located under the top glass G and can move back and forth while maintaining the optical path length, and a fixed imaging lens (hereinafter, referred to as a lens).
33, a linear image sensor (hereinafter, referred to as CCD) 35, etc.
(Polarizer) 42 and the like.

The automatic document feeder A has a difference in configuration from a conventional automatic document feeder, but its principle is known per se. Also, the original image reading section B, writing section D, image processing means (image carrying means) An image forming apparatus and an image forming process including a unit that forms a toner image on the body 10 and transfers the toner image onto a sheet) are well known.
The description is briefly given.

Incidentally, R10 shown on the front side of the transfer electrode 18 is a registration roller, H shown on the downstream side of the separation electrode is a fixing device, and a heating roller 91 and a pressure roller 92 pressed against the heating roller 91 are connected. And the heating roller 91
Then, the transfer material P on which the toner image has been transferred passes between the transfer material P and the pressure roller 92, so that the toner image is thermally fixed on the transfer material P.

The reversing mechanism X guides the transfer material P, on which image formation has been performed on one surface, to a reversing path 301 via a guide 300, guides the other surface of the transfer material P to the image forming section E, and transfers the image. This enables image formation on both sides of the material P.

In the above configuration, a process for forming a toner image on the image carrier 10, transferring the toner image onto the transfer material P, and then discharging the toner image to the paper discharge tray is as follows. One sheet of a document (not shown) placed on the document table 26 is transported in the document transport processing unit 28, and passes under the roller R1.
Slit exposure by the exposure means L is performed.

The reflected light from the original passes through mirror units 30 and 31 and a lens 33 at fixed positions, is coupled onto a CCD, and is read. The image information read by the document image reading unit B is processed by the image processing means, encoded, and stored in a memory on the image control board C.

The image data is called in accordance with the image formation, the laser light source 40 in the writing section D is driven according to the image data, and the image carrier 10 is exposed. Prior to this exposure, a predetermined surface potential is applied to the image carrier 10 rotating in the direction of the arrow (counterclockwise) by corona discharge of the charging electrode 14. As a result, an electrostatic latent image corresponding to the image data is formed on the image carrier 10.

The electrostatic latent image is reversely developed by the developing means 16 to be a visible image (toner image). On the other hand, the image carrier 10
Before the leading end of the upper toner image reaches the transfer area, for example, one sheet of the transfer material P in the feed tray 22 is fed and conveyed, reaches the registration roller R10, and is regulated at the leading end.

The transfer material P is a toner image, that is, the image carrier 10
The sheet is conveyed toward the transfer area by a registration roller R10 that starts rotating in synchronization so as to overlap the upper image area.

In the transfer area, the toner image on the image carrier 10 is transferred onto the transfer material P by the bias of the transfer electrode, and then the transfer material P is separated from the image carrier 10 by the bias of the separation electrode 20. Separated.

Thereafter, the toner powder forming the toner image is melted and fixed on the transfer material P by heating and pressing of the fixing device H, and the transfer material P is discharged through a discharge path 78 and a discharge roller 79. The sheet is discharged onto the tray T.

The image forming unit E includes a temperature sensor 30.
3. The storage unit F is provided with a humidity sensor 305. (Electrical Configuration) Next, the electrical configuration of the image forming apparatus having the above configuration will be described with reference to FIG.

The reference numeral 521 designates, as shown in FIGS.
In accordance with the size of the transfer material P, the paper feed trays 22 and 24 accommodating the transfer material P, the temperature, the humidity, and the front and back of the transfer material, the optimum rotation speed of the registration roller R10 (the reference rotation in this embodiment). 6 is a table in which the correction amount (%) of the rotation speed with respect to the number is recorded.

The reversing sensor 307 detects whether or not the transfer material P exists in the reversing path 301 of the reversing mechanism X in FIG. The control unit 500 includes a copy switch 501 provided on the operation panel, a number setting switch 503 for setting the number of copies, a paper size setting switch 505 for determining the size of the transfer material P, the tray 22,
24, a tray setting switch 507 for selecting one-sided copy mode or two-sided copy mode
The data from the / double-side setting switch 509, the environmental data from the temperature sensor 303 and the humidity sensor 305, and the data from the reversing sensor 307 are taken in, and a table 521 is acquired.
, The number of rotations of the driving motor of the registration roller R10 is determined, and the registration roller R10 is
The drive motor 513 is controlled.

(Operation) The operation of the image forming apparatus having the above configuration will be described with reference to FIG. When the copy switch 501 is turned on, the control unit 500 performs the following operation.

First, the copy number information is fetched from the copy number setting switch 503 (step 1), and the temperature sensor 303,
The environment data from the humidity sensor 305 is fetched (step 2), and the size of the transfer material P to form an image from the paper size setting switch 505 and the transfer material P is supplied from any of the trays 22 and 24 from the tray setting switch 507. Fetch the data (step 3).

Then, a table 5 is obtained from the acquired temperature data, humidity data, paper size data, and paper feed tray data.
21 to determine the rotation speed of the registration roller drive motor 513 that drives the registration roller R10 (step
4) The registration roller drive motor 513 is driven at the rotation speed determined via the driver 511 (step 5).

Next, the information from the simplex / duplex setting switch 509 is fetched, and if the mode is the simplex copy mode (step 6), the rotation of the registration roller drive motor 513 at the rotation speed determined in step 4 is continued (step 6). 7). Copies are made for the set number of copies taken in step 1 (step 8). When copying of the set number of copies is completed, driving of the registration roller drive motor 513 is stopped.
(Step 9).

On the other hand, if the mode is the double-sided mode in step 6, the information from the reversing sensor 307 determines that the next image formation is to form an image on the back side when the transfer material P is present on the reversing path 301, and to form an image on the front side when there is not. (Step 10) In the case of the front side, the rotation of the registration roller drive motor 513 at the rotation speed determined in Step 4 is continued (Step 11), and the process returns to Step 10.

If it is determined in step 10 that the sheet is the back side, the registration roller R10 is driven by referring to the table 521 again from the back side data in addition to the taken-in temperature data, humidity data, paper size data, and paper feed tray data. The number of rotations of the registration roller drive motor 513 is determined (step 1).
2), the registration roller driving motor 513 at the determined number of rotations.
Is rotated (step 13).

Then, copying is performed for the set number of copies taken in step 1 (step 14). When copying of the set number of copies is completed, the driving of the registration roller drive motor 513 is stopped (step 9).

According to the above configuration, the rotational speed of the registration roller R10 is controlled by the data of the size of the transfer material P, the tray in which the transfer material P is stored, the temperature, the humidity, and the data on the front and back of the transfer material. The degree of edge transfer deviation can be reduced.

The present invention is not limited to the above embodiment. In the above embodiment, the size of the transfer material P, the tray in which the transfer material P is stored, the temperature, the humidity,
The rotation speed of the registration roller R10 is controlled in accordance with at least one of the size of the transfer material P, the tray in which the transfer material P is stored, the temperature, the humidity, and the data on the front and back of the transfer material. Is controlled, it is possible to reduce the degree of rear-end transfer deviation.

In the above embodiment, the image carrier 1
0 and the fixing rollers 91 and 92 are driven by the same drive source,
By changing the rotation speed of the registration roller R10, the ratio of the conveyance direction of the image transfer material to the direction perpendicular to the conveyance direction (magnification ratio) can be adjusted. To reduce the number, the rotation speed of the registration roller R10 was changed.

In this case, if the rotational speed of the registration roller R10 must be largely changed in order to eliminate the occurrence of the transfer deviation at the rear end, the aspect ratio is greatly changed. Therefore, in the case where an accurate aspect ratio is required, the rotation speed of the registration roller R10 is determined based on the size of the transfer material P, the tray in which the transfer material P is stored, the temperature, the humidity, and the data on the front and back of the transfer material. It is also desirable to be able to switch between a mode in which is controlled and a mode in which it is not controlled.

Further, in the above configuration, the registration roller R1
Although the rotation speed of 0 is controlled, when the image carrier 10 and the fixing rollers 91 and 92 are driven by different driving sources, the rotation speed of the driving source for driving the fixing rollers 91 and 92 may be controlled. Good.

In this case, the degree of rear end transfer deviation is reduced,
Moreover, an image having an accurate aspect ratio can be obtained.

[0049]

As described above, according to the first and second aspects of the present invention, the size of the transfer material, the tray in which the transfer material is stored, the temperature and the humidity, and the front and back of the transfer material By controlling the rotation speed of at least one of the registration roller and the fixing roller in accordance with at least one of the conditions, the degree of rear end transfer deviation can be reduced.

The image bearing member and the fixing roller are driven by the same drive source, and the rotational speed of the registration roller is changed so that the ratio (longitudinal ratio) between the transport direction of the image transfer material and the direction orthogonal to the transport direction is obtained. In the adjustable image forming apparatus, the degree of the rear end transfer deviation can be reduced by changing the rotation speed of the registration roller as in the third aspect of the present invention.

In this case, if the rotational speed of the registration roller has to be largely changed in order to eliminate the occurrence of the rear end transfer deviation, the aspect ratio is greatly changed. A mode in which the rotation speed of the registration roller is changed, and a mode in which the rotation speed of the registration roller is not changed, in accordance with at least one condition among a size of a material, a tray accommodating the transfer material, temperature, humidity, and front and back of the transfer material. Thereby, an image having an accurate aspect ratio can also be formed.

On the other hand, when the image carrier and the fixing roller are driven by different driving sources,
By changing the rotation speed of the fixing roller, it is possible to reduce the degree of the rear end transfer deviation and obtain an image having an accurate aspect ratio.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an electrical configuration of an image forming apparatus according to an embodiment.

FIG. 2 is a diagram illustrating an overall configuration of an image forming apparatus according to an embodiment.

FIG. 3 is a diagram illustrating an operation of the image forming apparatus of FIG. 1;

FIG. 4 is a diagram showing an example of contents recorded in a table in FIG. 1;

FIG. 5 is a diagram showing an example of contents recorded in a table in FIG. 1;

[Explanation of symbols]

 500 control unit 521 table

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Miyoshi Nemoto, 2970 Ishikawacho, Hachioji-shi, Tokyo Inside Konica Corporation (72) Inventor Koichi Mizuno 2970, Ishikawacho, Hachioji-shi, Tokyo Inside Konica Corporation (72 ) Inventor Tomoya Motoyoshi 2970 Ishikawa-cho, Hachioji-shi, Tokyo F-term in Konica Corporation (reference) 2H027 DA11 DA14 DC19 ED25 EE03 EE04 2H028 BA03 BA06 BB02 BB04 2H033 AA45 BA08 BB38 CA02 CA11 CA13 CA17 CA40

Claims (5)

[Claims] 1. A transfer material is conveyed to an image bearing member having a toner image formed thereon using a registration roller, the toner image is transferred onto the transfer material, and the transfer material on which the toner image is transferred is fixed. In an image forming method for fixing the toner image transferred by heating and pressing with a roller onto the transfer material, the size of the transfer material, a tray containing the transfer material, temperature, humidity, and the transfer material An image forming method comprising: determining a rotation speed of at least one of the registration roller and the fixing roller according to at least one of the front and back conditions. 2. A transfer material is conveyed to an image carrier on which a toner image is formed using a registration roller, the toner image is transferred onto the transfer material, and the transfer material on which the toner image is transferred is fixed. An image forming apparatus for fixing the toner image transferred by heating and pressing with a roller onto the transfer material, the size of the transfer material, a tray containing the transfer material, a temperature, a humidity, and the transfer material. A table in which the relationship between at least one of the front and back data and the rotation speed of at least one of the registration roller and the fixing roller is recorded, and the size of the transfer material and the transfer material are stored. Tray, temperature, humidity, at least one of the front and back of the transfer material
An image forming apparatus comprising: a control unit that fetches two data, refers to the table, and determines a rotation speed of at least one of the registration roller and the fixing roller. 3. The image forming apparatus according to claim 2, wherein a rotation speed of the registration roller is changed. 4. A mode for changing a rotation speed of the registration roller in accordance with at least one of a size of the transfer material, a tray accommodating the transfer material, temperature, humidity, and front and back of the transfer material. 4. The image forming apparatus according to claim 3, further comprising: a mode that does not change. 5. The image forming apparatus according to claim 2, wherein a rotation speed of the fixing roller is changed.