JP2006062093A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which occurrence of reverse and creasing is prevented by cutting the forward end of a moist rolled sheet at the time of image formation. <P>SOLUTION: When the image forming apparatus is set to discharge the forward end of a sheet (S10; Y), humidity in a sheet feed unit and the time elapsed after sheet feed operation of a rolled sheet is performed previous time are checked (S11, S12). If a set value (a state causing reverse or creasing) is exceeded (S11;Y, S12;Y), a display is presented at an operating section in order to inquire a user whether the forward end of a sheet is cut and the sheet is discharged or not (S13). When the user selects discharge (S13; Y), the image forming apparatus starts sheet feed and a part of the sheet touching outer air in the sheet feed unit is cut by means of a cutter 22 before the sheet is discharged to the outside of the apparatus (S14). In case of an image forming apparatus having a plurality of sheet feed stages (S15; Y), above-mentioned control is repeated for each sheet feed stage (S16). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for preventing wrinkles and white spots of paper used for image formation.

Image forming apparatuses such as copying machines and facsimile machines perform image formation by printing on a predetermined sheet held by the apparatus.
If the inside of the paper feed unit that holds this paper is kept in a high humidity state, the roll paper inside will be damp and if you form an image on that paper, it will cause white spots and wrinkles. It had become.
As a technique for preventing such white spots and wrinkles, the inventions described in the following Patent Documents 1 to 3 can be cited.
Japanese Patent Laid-Open No. 5-8908 JP-A-8-151152 JP-A-8-282886

  Patent Documents 1 and 2 disclose a control method for keeping the humidity in the paper feeding unit constant. Patent Document 3 describes a method for preventing white spots and wrinkles by changing the front end position of the sheet.

By the way, when image formation is performed using roll paper, white spots and wrinkles are mostly generated when an image is formed in contact with the outside air at the leading edge of the paper. Therefore, if only the part of the roll paper that has been in contact with the outside air is cut in advance with a cutter to form an image, white spots and wrinkles can be largely prevented.
Accordingly, a first object of the present invention is to provide an image forming apparatus that prevents white spots and wrinkles from being generated by cutting the tip of a wet roll paper with a cutter when performing image formation. is there.
The second object of the present invention is that when the roll paper is not damp when the humidity is low or the like, if the roll paper tip is automatically discharged uniformly, the roll paper will be wasted, so only when necessary. An object of the present invention is to provide an image forming apparatus that cuts the leading edge of roll paper with a cutter.
A third object of the present invention is to provide an image forming apparatus that cuts only a portion that is in contact with outside air and takes measures against white spots and wrinkles.
A fourth object of the present invention is to provide an image forming apparatus capable of cutting and discharging the leading edge of the roll paper without waiting for an increase in the fixing pressure temperature when discharging the leading edge of the roll paper.
A fifth object of the present invention is to provide an image forming apparatus capable of determining whether or not to use a function for preventing white spots and wrinkles according to a user's selection.
A sixth object of the present invention is to provide an image forming apparatus capable of determining the timing of using a function for preventing white spots and wrinkles according to a user's selection.

According to a first aspect of the present invention, there is provided an image forming apparatus for forming an image on a roll paper in a paper feed unit by cutting the roll paper with a predetermined cutter, The first object is achieved by cutting the tip of the roll paper that has absorbed moisture with the cutter and discharging it to the outside of the machine.
According to a second aspect of the present invention, in the first aspect of the present invention, the humidity detecting means for detecting the humidity in the paper feeding unit, a timer for measuring the time since the last paper feeding operation, A water absorption state measuring means for determining the water absorption state of the leading end of the roll paper from the humidity detection means, the timer, and the measurement, and as a result of measurement by the water absorption state measurement means, the roll paper exceeds a predetermined water absorption state. Then, the cutter achieves the second object by cutting the leading end of the roll paper.

In invention of Claim 3, in invention of Claim 1 or Claim 2, the part which is the part which is touching the external air of each roll paper, and the part which is not wound, and one outer periphery are cut | disconnected with the said cutter. Thus, the third object is achieved.
According to a fourth aspect of the present invention, in the first, second, or third aspect of the present invention, paper feeding is started regardless of the fixing / pressing temperature of the image forming apparatus, and the cutter moves the leading end of the roll paper. The fourth object is achieved by cutting and discharging to the outside of the machine.

The invention according to claim 5 is the invention according to claim 1, claim 2, claim 3 or claim 4, further comprising an operation unit that presents predetermined information to the user and receives various inputs from the user. The fifth object is achieved by receiving selection of whether or not to cut the leading end of the roll paper with the cutter.
According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the timing for cutting the leading edge of the roll paper and discharging it to the outside of the apparatus is set at the time of turning on the power or starting the image forming operation at the operation unit. The sixth object is achieved by accepting.

According to the first to fourth aspects of the present invention, when using roll paper that has not been used for a long time, it is possible to prevent wrinkles and white-out images by cutting the tip including moisture. .
According to the fifth aspect of the present invention, useless consumption of roll paper can be prevented for a user who does not care about white spots or wrinkles.
According to the sixth aspect of the present invention, if the roll front end is ejected when the power is turned on, the start of image formation is not delayed, and if the roll paper front end is ejected before image formation, the image is formed even when the power is turned on. If you don't, you don't have to waste paper.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a diagram illustrating a configuration of an image forming apparatus including a paper cutter according to the present embodiment, FIG. 2 is a flowchart illustrating a processing procedure when power is turned on, and FIG. It is the flowchart which showed the processing procedure at the time.
In the image forming apparatus shown in FIG. 1, when a sheet is fed from the sheet feeding unit 20 to the drum unit 30 and the fixing unit 32, a cutter 22 that cuts the sheet by a predetermined length is provided. Further, this image forming apparatus is provided with a hygrometer for detecting the humidity in the paper feeding unit and a timer for measuring the use interval of the apparatus.

First, the processing procedure when the power is turned on will be described with reference to the flowchart of FIG.
When the image forming apparatus is turned on, it is first determined whether or not it is set to eject the leading edge of the sheet after the power is turned on (step 10). If it has been set to eject the leading edge of the paper (step 10; Y), the humidity inside the paper feeding unit is checked using a hygrometer (step 11), and the paper feeding operation is performed with the roll paper last time. The timer for the elapsed time is checked (step 12).
As a result of these checks, if it exceeds the set value (a condition that causes white spots and wrinkles) (step 11; Y, step 12; Y), the front end of the sheet is cut by displaying on the operation unit. The user is inquired whether or not to discharge (step 13).
As a result, when the user selects discharging (step 13; Y), the image forming apparatus starts feeding, cuts the length of the paper that is in contact with the outside air in the paper feeding unit with the cutter 22, and discharges it outside the machine. (Step 14). Thereafter, for an image forming apparatus having a plurality of paper feed stages (step 15; Y), the above control is repeated for each paper feed stage (step 16).

Next, a processing procedure at the time of image formation will be described with reference to the flowchart of FIG.
First, when performing image formation, it is determined whether or not the setting is such that the leading edge of the sheet is discharged during image formation. (Step 20). As a result, if the setting is made to eject the leading edge of the paper, the humidity in the paper feed unit is continuously checked (step 21), and the elapsed time since the previous paper feed operation was checked. (Step 22). As a result of the check, if it exceeds the set value (a state causing white spots / wrinkles) (step 21; Y, step 22Y), whether or not the front end of the sheet is cut and discharged by displaying on the operation unit The user is asked whether or not (step 23).
As a result, when the user selects discharge (step 23; Y), only the paper feed stage used for image formation starts feeding, and the length of paper that is in contact with the outside air in the paper feed unit is cut by the cutter 22, Discharge out of the machine (step 24). After paper discharge, image formation control is started (step 25).

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an exemplary embodiment. It is the flowchart which showed the process sequence at the time of power activation. It is the flowchart which showed the processing procedure at the time of image formation.

Explanation of symbols

20 Paper Feed Unit 22 Cutter 30 Drum Unit 32 Fixing Unit

Claims (6)

An image forming apparatus that feeds paper by cutting roll paper in a paper feed unit with a predetermined cutter,
An image forming apparatus, wherein a leading end portion of roll paper that has absorbed moisture in a paper supply unit during paper supply standby is cut by the cutter and discharged to the outside of the apparatus. Humidity detecting means for detecting humidity in the paper feeding unit;
A timer that measures the time since the last paper feed operation,
From the humidity detection means and the timer and measurement, water absorption state measurement means for obtaining the water absorption state of the leading end of the roll paper,
2. The image forming apparatus according to claim 1, wherein when the roll paper exceeds a predetermined water absorption state as a result of measurement by the water absorption state measuring means, the cutter cuts the leading end of the roll paper. The image forming apparatus according to claim 1, wherein an unrolled portion and one outer periphery of the roll paper that are in contact with the outside air are cut by the cutter. The paper feed is started regardless of the fixing / pressurizing temperature of the image forming apparatus, and the cutter cuts the leading end of the roll paper and discharges it outside the apparatus. 3. The image forming apparatus according to 3. An operation unit that presents predetermined information to the user and receives various inputs from the user,
5. The image forming apparatus according to claim 1, wherein selection of whether or not to cut the leading end of the roll paper is received by the cutter. 6. The image forming apparatus according to claim 5, wherein the operation unit accepts a setting as to whether the leading edge of the roll paper is cut and discharged outside the apparatus when the power is turned on or when the image forming operation is started.

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