JP2001002295A - Rolled paper feeding device in image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of curling regardless of feeding conditions by providing a rolled paper standby control device for allowing the rolled paper to stand by while successively feeding the same, with respect to predetermined standby positions of the rolled paper set on a plurality of places in the feeding direction. SOLUTION: When the copying operation is stopped, a point of the recording paper pulled out of the rolled paper is held on a predetermined position in a state of projecting by a predetermined amount from a nip part of a roller, and the standby position is properly changed by a standby control device 31. A timer counter 31d for measureing a standby time of the rolled paper is mounted in a central processing unit(CPU) 31a of the standby control device 31, the actual standby time of the rolled paper is measured, and a measured value is compared with a predetermined reference standby time in the CPU 31a. The reference standby time is specified every predetermined standby position of the rolled paper determined over a plurality of places, and a basic value of each reference standby time is determined corresponding to the possibility of the generation of curling of the rolled paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a roll paper transport device of an image forming apparatus such as a copying machine and a printer using roll paper.

[0002]

2. Description of the Related Art In general, in various image forming apparatuses using roll paper, the roll paper mounted in a roll unit is moved by a roll paper transport device so that the timing of forming a toner image on a photosensitive drum is adjusted. The paper is sent out so as to be unwound, cut into a predetermined size, and supplied to a transfer area.

When the image forming operation is not performed, the roll paper stops at a predetermined position and is in a standby state. However, the roll paper in the standby state may be stretched due to moisture or the like. A device in which the roll transport device is slightly rotated in the reverse direction immediately after stopping the drive to cause slackness, and always keeps the leading end of the roll paper in a fixed standby position to minimize the possibility of bending in the roll state A device for causing this to occur has conventionally been proposed.

[0004]

However, in taking the curl of the roll paper, the stand-by position for completely preventing the curl is different depending on the conditions of conveyance. Is not able to prevent roll bending habits well,
In some cases, it is not possible to provide a standby position that does not completely create a habit mechanically.Because it is held in a certain place for a long time, a bending habit such as a pressing trace of a roller is formed, and a jam or the like occurs. It may cause a conveyance failure.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a roll paper feeding device of an image forming apparatus which has a simple structure and is capable of favorably preventing the tendency of roll bending.

[0006]

In order to achieve the above object, according to the first aspect of the invention, a roll paper whose leading end portion is at a predetermined standby position is conveyed toward a transfer area, and the roll paper is transported. In the roll paper transport device of the image forming apparatus configured to form an image on the roll paper, a standby time storage storing a predetermined reference standby time for each of the scheduled standby positions of the roll paper set at a plurality of locations in the transport direction Means, counting means for measuring the actual standby time of the roll paper at each of the plurality of scheduled standby positions, and comparison determination means for comparing the standby measured time by the counting means with a reference standby time in the standby time storage means. And a paper transport unit for moving the roll paper to the next scheduled standby position on condition that both times match in the comparison determination unit.

According to a second aspect of the present invention, the standard standby time in the standby time storage means according to the first aspect is as follows:
It is set differently according to the remaining amount of roll paper.

Further, according to the third aspect of the present invention, the counting means according to the first aspect includes a cutting operation of roll paper,
It is configured to be cleared by operating the main power switch.

According to the first aspect of the present invention having such a configuration, the roll paper is sequentially transported and waited at the scheduled standby position of the roll paper set at a plurality of locations in the transport direction. In addition, irrespective of various transporting conditions, the occurrence of roll bending habit is well prevented.

In particular, since the bending tendency of the roll paper varies depending on the remaining amount of the roll paper, the configuration according to the second aspect of the present invention further reduces the bending tendency of the roll paper.

Further, according to the third aspect of the present invention,
The above-described standby control operation is always performed favorably.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a roll paper transport device in a fixing device according to the present invention is mounted on a copying machine will be described below in detail with reference to the drawings.

The copier 1 shown in FIG. 1 is applicable to both cut paper in which recording paper is cut into a sheet and roll paper in which long recording paper is wound in a cylindrical shape. The apparatus is configured so that an image can be selectively formed. As a sheet feeding apparatus, a cassette 14 for storing cut sheets, and sheet recording paper of each size, large and small, are placed and fed. A manual tray 19 and a roll paper unit RU for storing roll paper are provided.

The cassettes 14 are mounted so that they can be inserted into and removed from the front side of the body of the copier 1 in multiple stages in different sizes, and a plurality of cut sheets are stacked in each of the cassettes 14. It is housed in a shape. The manual feed tray 19 is provided so as to extend obliquely upward from one side (the right side in the figure) of the main body of the copying machine 1. The manual feed tray 19 has a size from A3 size to large and small like a postcard. A plurality of sheet-like recording papers are placed and fed. Further, the roll paper unit RU is disposed below the manual feed tray 19 and is mounted so as to be able to be moved in and out of the main body of the copying machine 1 laterally.

More specifically, an original glass table 2 serving as an original table is arranged substantially horizontally on the upper surface of the main body of the copying machine 1, and an image is read directly below the original glass table 2. A scanner (scanning optical device) 3 constituting the means is provided. The scanner 3 has an illumination lamp 3a for irradiating the original (not shown) on the original glass table 2 with scanning light and guides reflected light from the original onto a photosensitive drum 4 described later. Mirror 3b
And a projection lens 3c.

A platen cover 5 is provided on the platen glass 2 so as to cover the platen glass 2 so as to be openable and closable. The platen cover 5 is provided with the illumination lamp 3
a is stopped at a predetermined position and a document is fed while a document is being conveyed. The document feeder (DF) 5a is used for scanning (sheet through). The document is stopped at a predetermined position and the illumination lamp 3a is moved. And an automatic document feeder (AF) 5b for reading.

A photosensitive drum 4 as an image carrier is provided below the scanner 3 so as to be driven to rotate clockwise in the drawing. Around the photosensitive drum 4, a charger 6 for uniformly charging the photosensitive drum 4, and a toner is applied to an electrostatic latent image formed on the photosensitive drum 4 by exposing the scanning light from the scanner 3 to light. A developing device 7 for supplying and forming a face image, a transfer charger 8 located in the middle of the paper transport path for transferring the toner image on the photosensitive drum 4 to the recording paper side, and separating the transferred recording paper from the photosensitive drum 4 A separation charger 9 for performing the operation, a cleaning device 10 for removing the toner remaining on the photosensitive drum 4 after the transfer, and the like are sequentially arranged along the rotation driving direction of the photosensitive drum 4.

Further, the toner image on the recording paper is thermally transferred to the exit side end of the belt-shaped paper transport path 11 extending from the transfer band dragon 8 and the separation charger 9 toward the exit of the apparatus main body. A fixing device 12 for fixing is provided, and the above-described paper discharge tray 13 is mounted at an outlet of the fixing device 12. Further, immediately below the belt-shaped paper distribution path 11, cassettes 14 for storing cut paper for each size are provided in four stages.

A paper feed roller 15 is disposed above the outlet on the right side of each paper feed cassette 14 in the drawing, and the paper feed rollers 15 are transferred from these paper feed rollers 15 to the transfer section of the photosensitive drum 4. Toward, the transport paths 16 extend. Each of these transport paths 16 merges into a single transport path 17. A registration roller that feeds recording paper to the transfer section in the vicinity of the transfer section in the merged transport path 17 in synchronization with the image forming process. 18 are provided.

Next, the structure of the roll paper supply device will be described. FIG. 2 shows a roll paper unit in the copying machine shown in FIG. A roll paper unit RU integrally provided with a roll paper 20 and the like is pulled out toward the right side in the drawing from the main body of the copying machine 1 on a side portion (right side portion in the figure) of each of the above-described paper supply cassettes 14. Mounted as possible.
A pair of spool holders 26 for rotatably holding the roll paper 20 are provided upright at a lower portion in the roll paper unit RU so as to face each other at a predetermined interval.

The roll paper 20 is formed by winding a long recording paper around a cylindrical core tube, and is exchangeably mounted inside the roll paper unit RU. When the roll paper 20 is mounted, first, a long rod-shaped spool 25 is penetrated into the core tube, and both ends of the spool 25 are opposed to concave groove-shaped receiving portions formed by cutting out the spool holder 26. It is designed to be rotatable. On the other hand, when the recording paper of the roll paper 20 has been consumed, the roll paper is removed in a procedure opposite to the procedure described above, and a new roll paper 20 is mounted in the same manner.

A roll paper transport mechanism is provided immediately above the roll paper 20 mounted in the roll paper unit RU, and transports the recording paper pulled out so as to unwind the roll paper 20. The roll paper transport mechanism includes a paper feed roller 22 and a transport roller 23 that are disposed at predetermined intervals on the upstream side and the downstream side in the paper transport direction (left direction in the drawing), and is disposed on the downstream side in the paper transport direction. Transport roller 2
From 3, the transfer path 21 is provided so as to extend diagonally upward. The transport path 21 is connected to the merging transport path 17 toward the registration roller 18 described above. The leading end portion of the recording paper pulled out from the roll paper 20 is sandwiched between a paper supply driving roller 22a and a paper supply pressure roller 22b constituting the paper supply roller 22 until the paper supply is started. The paper is waiting in a state where the leading end of the paper protrudes by a predetermined amount from the nip portions of the two-side rollers 22 and 23. The leading end position of the roll paper 20 at this time is detected by a paper presence / absence sensor 30 provided at the exit of the paper feed roller 22.

When the copying operation is started, the recording paper is fed from the above-described standby position by the rotational driving force of the rollers 22 and 23, and is moved toward the transfer area (photosensitive drum 4) in synchronization with the copying operation. It is conveyed toward.

The paper feed roller 22 and the transport roller 2
3 is provided in the transport path at the portion between
There is provided a cutter 24 as a cutting means for cutting the recording paper drawn out of the printer at a predetermined length. The cutter 24 has a rotary blade that moves so as to cross in the paper width direction, and the rotary blade operates at a predetermined timing according to a command from a roll paper supply control unit (not shown).

When the copying operation is stopped, the leading end of the recording paper pulled out from the roll paper 20 is held at a predetermined standby position. The standby position is appropriately changed depending on the situation at that time. It has become so.
Hereinafter, the standby control device 31 that changes the standby position of the roll paper 20 will be described together with the standby control operation.

As shown in FIG. 3, a detection signal from the above-mentioned paper presence / absence sensor 30 is received by an input side of a central processing unit (hereinafter, referred to as a CPU) 31a in a standby control device 31, and its The driver 32 of the transport system drive motor is connected to the output side of the CPU 31a. In the standby control device 31, for the CPU 31a, a ROM 31b in which a control program described later is stored,
And a RAM 31c for temporarily storing various data.

Further, the CPU 3 of the standby control device 31
A timer counter 31d for measuring the standby time of the roll paper 20 is provided in 1a. The timer counter 31d measures the actual standby time after the roll paper 20 enters the standby state, and the standby time measurement value is set in advance in the CPU 31a in the ROM 31b or the RAM 31c. This is compared with the standard standby time.

The reference standby time is defined for each scheduled standby position of the roll paper 20 set at a plurality of locations. In the present embodiment, as shown in FIG. 4, the scheduled standby position of the leading end of the roll paper 20 is Al,
9 of A2, A3, B1, B2, B3, Cl, C2, C3
The reference standby time is 8 hours for Al, A2, and A3, the reference standby time is 4 hours for B1, B2, and B3, and the reference standby time is 6 hours for Cl, C2, and C3. Are set as basic settings. The basic value of each of these reference standby times is the roll paper 20
Is set in accordance with the tendency of the roll to have a curl, and the place where the curl is likely to occur is set in a short time.

Next, the contents of a control program provided in the standby control device 31 will be described with reference to a flowchart. As shown in FIG. 5, first, at the time of power-on (Step 1), a check operation of the roll unit RU is performed (Step 2), and when there is no roll paper (No in Step 3). Since the control is unnecessary, the process exits the control routine (step 4). Note that the condition when there is no roll paper in step 2 described above includes a case where the length of the roll paper 20 is less than the shortest length that can be copied.

On the other hand, if the roll unit RU contains roll paper of a length that can be copied (Yes in step 3), a roll paper standby control operation described later is performed (step 5). This roll paper standby control operation
While the leading end of the roll paper 20 is moved to the most appropriate place in consideration of the previous roll paper standby position and is made to stand by, a paper transport operation as shown in FIG. 6 is performed, for example.

That is, as shown in FIG. 6, prior to the roll paper standby control operation, the presence or absence of the cut operation of the roll paper 20 is detected, and the cut length by the cut operation is determined as follows.
When all the planned standby positions Al to C3 in FIG. 4 described above are included, data all is set in the cut position information Pcut (step 1). As a result, all of the aforementioned scheduled standby positions Al to C3 are set as control targets. When the data all is set in the cut position information Pcut (Yes in step 1), the previous cut position information Pcut and the standby position information Pold are cleared to zero.

In this way, the standby position information P
When old is cleared to 0 or when the new roll paper 20 is set and the standby position information Pold is set to 0 (Yes in step 3), the scheduled standby position is set in the roll paper standby position information Pnow. Is set as the initial value of (step 4). On the other hand, if the standby position information Pold is other than 0 (No in step 3), for example, the position corresponding to the next standby position is a function h (x) in the order as shown in FIG. And the next scheduled standby position is set in the roll paper standby position information Pnow (step 5).

In this manner, when the next scheduled standby position is determined based on the roll paper standby position information Pnow, the reference standby time Tp at that position is, for example, Tp = Tp * Qn (n = It is calculated by a function f (x) such as (0, 1, 2, 3) (step 6). Tp * in the above equation is a basic value of the above-described reference standby time, and Qn is a coefficient corresponding to the roll diameter. The coefficient Qn is set smaller as the roll diameter is smaller. In the present embodiment, the coefficient Qn is divided into four pitches of n = 0 to 3, and n =
1.0 for 0, 0.8 for n = 1, n = 2
Is set to 0.6 in the case of and to 0.4 in the case of n = 3.

Next, based on the roll paper standby position information Pnow obtained as described above, the leading end of the roll paper 20 is transported and moved to a target scheduled standby position by a function g (x) (step 7). When the movement is completed, the count value of the timer counter 31d is cleared to 0, and the next counting operation is started (step 8).

Returning to FIG. 5, after the above-described roll paper standby control operation is completed (step 4), if there is no request for cocopying start (No in step 6), the presence or absence of roll paper is checked. If it exists (Ye in step 7)
s) After waiting until the count value of the timer counter 31d reaches the reference standby time Tp (step 8), the timer count value is cleared to 0 (step 9), and the above-described roll paper standby control operation is performed again.

On the other hand, after the end of the roll paper standby control operation (step 4), if there is a copy start request (Yes in step 6), after the timer count value is cleared to 0 (step 10), the roll paper A transfer control operation is performed (step 11).

In this embodiment, the scheduled standby positions Al to Roll paper 20 set at a plurality of positions in the transport direction are described.
Since the leading end position of the roll paper 20 is sequentially moved and conveyed with respect to C3 and is on standby, the occurrence of roll bending habit is well prevented regardless of various conveyance conditions.

In particular, since the habit of the roll paper varies depending on the remaining amount of the roll paper, in the present embodiment, the standby time is changed by a coefficient corresponding to the roll diameter.
The generation of the curl of the roll paper is more effectively prevented.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above embodiments, and it is needless to say that various changes can be made without departing from the gist of the present invention. For example, the present invention can be similarly applied to an image forming apparatus other than the copying machine as in the above-described embodiment.

[0040]

As described above, according to the first aspect of the present invention, the roll paper standby is performed in such a manner that the roll paper is sequentially transported and waited at the scheduled standby position of the roll paper set at a plurality of positions in the transport direction. By providing the control device, the roll bending habit can be satisfactorily prevented irrespective of the transport conditions, so that the roll bending habit can be satisfactorily prevented with a simple configuration. In addition, the paper quality can be improved by always enabling stable paper conveyance.

According to a second aspect of the present invention, the reference paper standby time in the standby time storage means is set differently in accordance with the remaining amount of the roll paper, whereby the curl of the roll paper is changed. Therefore, the above effects can be further enhanced.

According to a third aspect of the present invention, the standby means is always satisfactorily performed by clearing the counting means according to the first aspect of the present invention by a roll paper cutting operation and a main power switch operation. With such a configuration, the above-described effects can be further enhanced.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an example of a copying machine employing a roll paper transport device according to the present invention.

FIG. 2 is a partially enlarged explanatory view showing the roll transport device shown in FIG. 1;

FIG. 3 is a block diagram illustrating an example of a roll paper standby control device.

FIG. 4 is a diagram illustrating a setting example of a scheduled standby position.

FIG. 5 is a flowchart showing the entire standby control procedure.

FIG. 6 is a flowchart showing a main part of a roll paper standby control procedure.

FIG. 7 is a green garden showing an example of changing a scheduled standby position.

[Explanation of symbols]

 RU roll paper unit 4 photosensitive drum 20 roll paper 22 paper feed roller 23 transport roller

Claims (3)

[Claims] 1. A roll paper transport device of an image forming apparatus configured to transport a roll paper having a paper leading end at a predetermined standby position toward a transfer area and form an image on the roll paper. A standby time storage unit that stores a predetermined reference standby time for each of the roll paper scheduled standby positions set at a plurality of locations in the direction, and measures an actual standby time of the roll paper at each of the plurality of scheduled standby positions. Counting means; comparison and determination means for comparing the standby measurement time by the counting means with a reference standby time in the standby time storage means; and A roll paper transport device for an image forming apparatus, comprising: a paper transport means for moving to a scheduled standby position. 2. A roll paper transport device for an image forming apparatus, wherein the reference standby time in the standby time storage means according to claim 1 is set differently in accordance with the remaining amount of roll paper. 3. The roll paper of the image forming apparatus according to claim 1, wherein the counting means is cleared by a roll paper cutting operation and a main power switch operation. Transport device.