JPH09274345A - Paper feeder - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] In a paper feeding device that cuts and feeds roll paper with a cutter, the roll paper has a large thermal inertia when the temperature rises after the power is turned on or when the temperature falls after the power is turned off. Avoid being affected by heat from the cutter. SOLUTION: After the roll papers 5a to 5d are cut by the cutter 12, the cut portions of the roll papers 5a to 5d are separated from the cutter 12 by a predetermined dimension by reversing the roll paper conveying means 6a to 6d. The influence of the heat on the roll papers 5a to 5d is prevented. As a result, it is possible to prevent the water content of the roll papers 5a to 5d affected by the heat from the cutter 12 from becoming nonuniform and causing waviness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device of an image forming apparatus using roll paper.

[0002]

2. Description of the Related Art Conventionally, as a sheet feeding device of an image forming apparatus using roll paper, Japanese Patent Laid-Open No. 5-333634, Japanese Patent Laid-Open No. 59-26843, and Japanese Patent Laid-Open No. 59-33466.
What is disclosed in Japanese Patent Publication No. These paper feeding devices are provided with a forward / reverse rotatable paper feeding roller for feeding the roll paper toward the image forming unit, a cutter for cutting the roll paper at a predetermined position, and the like.

In the above-mentioned paper feeding device, the cutting portion of the roll paper cut by the cutter remains stopped at a position close to the cutter.

Further, in the paper feeding device of Japanese Patent Laid-Open No. 5-333634, a plurality of roll papers are conveyed to the cutter position through the common conveyance path, and the leading ends of the plurality of roll papers are overlapped in the common conveyance path. It is waiting in a standing state.

[0005]

The cutter has a large mass and a large thermal inertia. For this reason, when the temperature inside the image forming apparatus is raised by turning on the power, the temperature rise around the cutter is slower than that in other portions. On the other hand, when the power is turned off, the temperature drop around the cutter becomes slower than that in other parts.

For this reason, when the cut portion of the roll paper is located close to the cutter, the temperature in the vicinity of the cut portion of the roll paper and the temperature of the other portion of the roll paper will vary, and such a partial temperature will occur. Due to such variations, the water content of the roll paper becomes uneven, and the unevenness of the water content causes the roll paper to become wavy. When an image is formed on a corrugated roll paper, the roll paper is wrinkled, resulting in a marked deterioration in image quality.

Further, if the leading ends of a plurality of roll papers are kept waiting in a state of being overlapped with each other in the common transport path, when one roll paper is transported, it is rubbed against another roll paper and frictionally charged. , The paper is electrostatically attracted to other roll paper to cause a jam, or the leading end of the roll paper is broken. In particular, when the roll paper is film paper, tracing paper, or the like, triboelectric charging is likely to occur, and jamming or ear breakage due to electrostatic attraction is likely to occur.

[0008]

According to the first aspect of the present invention,
Forward / reverse roll paper transport means for transporting the roll paper loaded in the loading position in the paper feed direction and the return direction, and cutting the roll paper transported in the paper feed direction by the normal rotation of the roll paper transport means. In a paper feeding device equipped with a cutter, the roll paper is conveyed in the returning direction by reversing the roll paper conveying means after the roll paper is cut by the cutter and the cutting portion of the roll paper is cut from the cutter by a predetermined amount. The dimensions are separated. Therefore, when the temperature rises after the power is turned on or when the temperature falls after the power is turned off, the cut side of the roll paper is not affected by the heat from the cutter with a large thermal inertia, and the entire roll paper has a uniform temperature. As a result, the water content of the entire roll paper becomes uniform, and the waviness of the roll paper caused by the non-uniform water content is prevented.

According to a second aspect of the present invention, a plurality of roll paper transporting means which can transport the plurality of roll papers mounted at the plurality of mounting positions individually in the paper feeding direction and the returning direction, respectively, and a plurality of roll paper transporting means capable of rotating in the forward and reverse directions. Paper feed provided with a common transport path for transporting each roll paper transported in the paper feed direction by the normal rotation of the roll paper transport means, and a cutter located in the middle of the shared transport path for cutting the roll paper In the apparatus, after cutting the roll paper with the cutter, the roll paper conveying means is reversed to convey the roll paper in the returning direction so that the cut portion of the roll paper is retracted from the shared conveyance path. Therefore, when the roll paper is fed, the roll paper does not rub against other roll papers in the shared conveyance path to be triboelectrically charged, and the triboelectrically charged roll paper is electrostatically attracted. Jam and ear breakage are prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the entire structure of a copying machine which is an image forming apparatus. An upper tray 2 and a lower tray 3 are accommodated in a lower portion of a main body case 1 so as to be slidable in a horizontal direction. Paper spool 4 in upper tray 2
The roll papers 5a and 5b set on a and 4b are loaded, and the roll papers 5c and 5d set on the paper spools 4c and 4d are also loaded in the lower tray 3. When these roll papers 5a to 5d are mounted in the trays 2 and 3, the leading ends of the roll papers 5a to 5d are held by the feed rollers 6a, 6b, 6c and 6d which are roll paper conveying means. These feed rollers 6a to 6d are connected via a clutch to a drive motor (not shown) that can rotate forward and backward. Further, a rotary operation knob (not shown) for manually rotating the feed rollers 6a to 6d is connected to the feed rollers 6a to 6d.

The roll paper 5a is placed on the upper tray 2.
An individual transport path 7a for transporting the roll paper, an individual transport path 7b for transporting the roll paper 5b, and the roll paper 5
A common transport path 8a for transporting a and 5b and roll papers 5c and 5d of the lower tray 3 is formed. A fixed blade 9a and a slitter 10a for cutting the leading ends of the roll papers 5a and 5b when the roll papers 5a and 5b are mounted on the shared transport path 8a, and roll papers 5a to 5d transported in the shared transport path 8a. A size sensor 11 for detecting the size, a cutter 12 for cutting the roll papers 5a to 5d conveyed in the common conveyance path 8a and conveyed to an image forming unit described later to a predetermined length, and image formation for the roll papers 5a to 5d. A relay roller pair 13 that conveys the sheet toward the sheet and a cut length sensor 14 that detects the cut length of the roll papers 5a to 5d are provided.
The cutter 12 includes a fixed blade 12a and a rotary cutter 12
b. An exit 15 is formed at the tip of the shared conveyance path 8a.

The lower tray 3 has the roll paper 5c.
And an individual transport path 7c for transporting the roll paper 5d, and an individual transport path 7d for transporting the roll paper 5d.
A common transfer route 8b for transferring c and 5d is formed. Roll papers 5c, 5 are provided on the shared conveyance path 8b.
A fixed blade 9b and a slitter 10b for cutting the leading end portions of the roll papers 5c and 5d when the d is mounted are provided, and the common transport path 8 is provided.
An outlet 16 is formed at the tip of b.

When the upper tray 2 and the lower tray 3 are pushed into the main body case 1 to be in the state shown in FIG. 1, the common transport paths 8a and 8b communicate with each other, and the exit 15 of the common transport path 8a shows an image. It communicates with the transport path of the forming unit.

An image forming section 20 having a photosensitive drum 17, a developing device 18, a transfer charging device 19 and the like is provided in an upper part of the main body case 1, and rolls 5a fed to the image forming section 20. A fixing unit 21 for fixing the toner image transferred to 5d is provided. On the upper surface of the body case 1,
A paper discharge tray 22 is provided for discharging the roll papers 5a to 5d that have passed through the fixing unit 21.

In this copying machine, input data from various keys (not shown) provided on the operation panel, detection data from the sensors 11 and 14 and other sensors not shown, and stored in the ROM. Based on a control program or the like, the feed rollers 6a to 6d and the cutter 12 are
Also, a control unit (not shown) having a microcomputer configuration for controlling the image forming unit 20 and the like is provided.

In such a structure, first, mounting of the roll papers 5a to 5d on the trays 2 and 3 will be described. The trays 2 and 3 are pulled out from the main body case 1, and the roll papers 5a to 5d set on the paper spools 4a to 4d
Is mounted in the main body case 1 at the mounting position. At the time of this mounting, the leading ends of the roll papers 5a to 5d are held by the feed rollers 6a to 6d.

By holding the leading end of each roll paper 5a-5d between the feed rollers 6a-6d, the roll papers 5a-5d
After the attachment of 5d is completed, turn the rotary operation knob. Then, the feed rollers 6a to 6d rotate and the roll papers 5a to 5d are fed out. The leading ends of the roll papers 5a and 5b on the upper tray 2 pass through the common conveyance path 8a and exit 1
Get out of 5. The leading ends of the roll papers 5c and 5d on the lower tray 3 exit from the outlet 16 through the shared conveyance path 8b.

The leading ends of the roll papers 5a to 5d are the outlets 15,
After exiting from 16, the manual cutting knob is operated to rotate the slitters 10a and 10b, and the fixed blades 9a and 9b are rotated.
The leading ends of the roll papers 5a to 5d are cut by sliding the roll papers along b. The leading ends of the cut roll papers 5a to 5d are taken out from the outlets 15 and 16.

After the leading ends of the roll papers 5a to 5d cut by the slitters 10a and 10d are taken out from the outlets 15 and 16, the upper tray 2 and the lower tray 3 are pushed into the main body case 1. When the upper tray 2 and the lower tray 3 are pushed into the main body case 1, the feed rollers 6a to 6d are sequentially driven, and the roll papers 5a to 5d are conveyed to the position of the size sensor 11 and their size is detected. At this time,
The remaining amount of the roll papers 5a to 5d is detected from the rotation amounts of the feed rollers 6a to 6d and the paper spools 4a to 4d.

The roll papers 5a to 5d subjected to the size detection and the remaining amount detection are rewound until the leading ends of the roll papers 5a to 5d return to the positions of the individual conveying paths 7a to 7d by the reverse rotation of the feed rollers 6a to 6d, and Wait at the position. That is,
According to the control program stored in the ROM, the feed roller 6 is triggered by the execution of the size detection and the remaining amount detection.
Control is performed to reversely drive a to 6d. When the roll papers 5a to 5d are not mounted at any of the mounting positions, the paper spools 4a to 4d do not rotate even if the feed rollers 6a to 6d rotate, and thus it is detected that the roll papers 5a to 5d are not present. The size is not detected. All roll papers 5a mounted in this way
By completing the size detection and the remaining amount detection for .about.5d, the roll papers 5a to 5d are ready to be fed.

After the temperature of the fixing section 21 rises to the fixing possible temperature, when the original is set in the original reading section and the copy start button is pressed, one roll paper 5a selected from the original size, the magnification and the like is fed. In order to do so, one feed roller 6a is driven. The roll paper 5a that is fed by the drive of the feed roller 6a passes through the shared conveyance path 8a and is fed to the image forming unit
It is transported toward zero. Then, during this conveyance, it is determined whether or not the roll paper 5a is jammed by measuring the time until the leading edge of the roll paper 5a is detected by the size sensor 11. Further, after the leading end of the roll paper 5a has passed the size sensor 11, the cut length sensor 14
It is determined whether or not a jam has occurred again by measuring the time until it is detected.

When the roll paper 5a thus conveyed reaches the image forming section 20, the toner image formed on the outer peripheral surface of the photosensitive drum 17 is transferred to the roll paper 5a, and the roll paper 5a is fixed in the fixing section 21. The toner image transferred when passing the sheet is fixed, and the roll paper 5a having the toner image fixed is discharged onto the discharge tray 22. The cut length sensor 14 starts counting after the front end of the roll paper 5a is detected by the cut length sensor 14, and the rotary cutter 12b is rotated at a certain timing based on the count.
The roll paper 5a is cut by coming into contact with the fixed blade 12a.

If an input is made to continue copying using the roll paper 5a, the roll paper 5
The sheet a is continuously conveyed toward the image forming unit 20, and the transfer of the toner image, the counting by the cut length sensor 14, the cutting by the cutter 12, and the like are repeated.

On the other hand, when the copying operation using the roll paper 5a is finished after the roll paper 5a is cut by the cutter 12, the feed roller 6a is reversed and the roll paper 5a is conveyed in the returning direction. The cut portion of the roll paper 5a cut by the cutter 12 is retracted from the common transport path 8a and returned to the individual transport path 7a. That is, according to the control program stored in the ROM, the control of driving the feed roller 6a in reverse is triggered by the execution of the final cutting of the cutter 12 on the roll paper 5a. As a result, the cut portion of the roll paper 5a is not affected by the heat from the cutter 12 having a large thermal inertia, and the entire temperature of the roll paper 5a becomes uniform when the copier is turned on or turned off. The water content of the roll paper 5a is also uniform, and the occurrence of waviness of the roll paper 5a due to the non-uniformity of the water content is prevented. Therefore, wrinkling does not occur on the roll paper 5a that has passed through the fixing unit 21 due to the transfer of the toner image to the roll paper 5a that has been wavy and passing through the fixing unit 21. The quality of the image transferred to is improved. In addition, the slitter 10a,
Since 10b has a smaller thermal inertia than the cutter 12, the slitters 10a and 10b can be separated by separating the cut portion of the roll paper 5a from the slitters 10a and 10b by about 10 mm.
No longer affected by heat from

Further, by retracting the cut portion of the roll paper 5a from the common conveyance path 8a and returning it to the inside of the individual conveyance path 7a, when the other roll papers 5b to 5d are conveyed inside the common conveyance path 8a, The roll papers 5b to 5d and the roll paper 5a do not rub against each other to be triboelectrically charged.
Therefore, it is possible to prevent the occurrence of jams, folds of the ears, etc. due to electrostatic attraction of the triboelectrically charged roll papers 5a to 5d in the common conveyance path 8a.

In the method of rewinding the roll paper 5a into the individual transport path 7a, the feed roller 6a is rotated in the reverse direction and its rotational force is transmitted to a hysteresis clutch (not shown) so that the rotational force is transmitted to the paper spool 4a. Then, the roll paper 5a can be rewound between the paper spool 4a and the feed roller 6a without slackening. As another rewinding method, the clutch of the feed roller 6a may be disengaged to directly reverse the paper spool 4a.

Here, the cutter 1 of the fed roll paper 5a
Regarding the cutting by 2 and the rewinding after cutting, only one roll paper 5a has been described, but other roll papers 5a
The same applies to b to 5d.

The application of the present invention is not limited to the present embodiment, and the roll paper transporting means for transporting the roll paper in the paper feeding direction and the returning direction and the roll paper transporting means for cutting the roll paper are provided. The present invention can be applied to any paper feeding device having a cutter regardless of its form.

[0029]

According to the first aspect of the present invention, after the roll paper is cut by the cutter, the roll paper conveying means is reversed to convey the roll paper in the returning direction to cut the cut portion of the roll paper. Since it is separated by a predetermined size from the above, when the temperature rises after the power is turned on or when the temperature falls after the power is turned off, the cut side of the roll paper is not affected by the heat from the cutter with high thermal inertia. The entire roll paper can be heated to a uniform temperature to make the water content of the roll paper uniform, and the occurrence of waviness in the roll paper caused by the uneven water content can be prevented. It is possible to prevent wrinkles on the roll paper that occur when paper is fed to form an image, and the quality of the image on which the image is formed can be improved.

According to the second aspect of the present invention, after the roll paper is cut by the cutter, the roll paper conveying means is reversed to convey the roll paper in the returning direction and the cutting portion of the roll paper is used as the common conveyance path. Since it is retracted from the roll paper, it is possible to prevent the roll paper from rubbing against other roll paper in the shared transport path and frictionally charged when the roll paper is fed, and the frictionally charged roll paper is electrostatically adsorbed. It is possible to prevent jams of the roll paper and folds of the ears that are caused by

[Brief description of drawings]

FIG. 1 is a front view showing the overall structure of a copying machine including a sheet feeding device according to an embodiment of the present invention.

[Explanation of Codes] 5a to 5d Roll Paper 6a to 6d Roll Paper Conveying Means 8a, 8b Shared Conveying Path 12 Cutter

Claims (2)

[Claims] 1. A roll paper transporting means for transporting a roll paper mounted at a mounting position in a paper feeding direction and a returning direction, and a roll paper transporting means for transporting the roll paper in a paper feeding direction by forward rotation. In a paper feeding device provided with a cutter for cutting roll paper, the roll paper is conveyed in the returning direction by reversing the roll paper conveying means after the roll paper is cut by the cutter, and the roll paper cutting unit The sheet feeding device is characterized in that the sheet is separated from the cutter by a predetermined dimension. 2. A plurality of roll paper transporting means capable of forward and reverse rotation for individually transporting a plurality of roll papers mounted at a plurality of mounting positions in a paper feeding direction and a returning direction, respectively, and these roll paper transporting means. In a paper feeding device provided with a common transport path for transporting each roll paper transported in the paper feed direction by forward rotation, and a cutter located in the middle of the common transport path for cutting the roll paper, Paper feeding characterized in that after the roll paper is cut, the roll paper conveying means is reversed to convey the roll paper in the returning direction so that the cut portion of the roll paper is retracted from the shared conveyance path. apparatus.