JPH11180603A - Rolled paper unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely create a prescribed quantity of loop space without being influenced by the stiffness of a rolled paper by providing a driving means selectively stopped to both a guide position and a loop forming position on the guide member of a rolled paper unit. SOLUTION: When the top end part 72a of a rolled paper 72 is detected by an output sensor 110, rotation of a decurling roller 90 is stopped, but a feed roller 86 continues to rotate to begin the formation of the loop of the rolled paper 72. The feed to a solenoid 101 is also stopped simultaneously with the detection, and a guide member 87 is rotated down and stopped in a loop forming position to create a space allowing the formation of a prescribed quantity of loop above a guide surface 87a. Since the guide member 87 is selectively stopped in both of a guide position and the loop forming position by the driving means solenoid 101, the space allowing the formation of a prescribed quantity of loop can be surely created regardless of the stiffness of the rolled paper 72.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll paper unit which is removably incorporated in an image forming apparatus for forming an image on roll paper.

[0002]

2. Description of the Related Art As an output device of a computer or a workstation, an ink jet type image forming apparatus for forming an image on a print medium (recording medium) by discharging ink, or forming an image on a print medium using a developer or the like. There is known an electrophotographic image forming apparatus. Some of these image forming apparatuses can selectively use both cut paper and roll paper as a print medium. There is also a type in which only roll paper can be used as a print medium. Such a type of image forming apparatus includes a roll paper unit for storing roll paper, and the roll paper is fed from the roll paper unit to an image forming unit inside the apparatus to form an image.

When an image is formed on a roll paper, an image in an image area longer than the transport distance from the roll paper storage position where the roll paper is stored to the image forming section is usually formed on the roll paper. May be. For this reason, the roll paper is cut by a length corresponding to the length of the image area while forming an image by forming a loop of the roll paper when feeding and transporting the roll paper. This cutting is performed while the loop of the roll paper is being formed, and the paper feeding operation and the image formation are continued. Thus, the cutter for cutting the roll paper and the guide member for guiding the roll paper to the image forming section are incorporated in the image forming apparatus.

A conventional roll paper unit will be described with reference to FIGS.

FIG. 7 is an enlarged schematic view of a main part of a conventional roll paper unit, showing a state in which the leading end of the roll paper is guided toward a decurling roller. FIG. 8 is an enlarged schematic view of a main part of a conventional roll paper unit, showing a state where an insufficient loop is formed.

The roll paper 72 is sandwiched between a pressure roller 84 and a paper feed roller 86, and is guided by a cutter lower blade guide 78 and a guide plate 120 by rotation thereof, and is fed to a decurling roller 90. The cutter 100 that cuts the roll paper 72 is disposed downstream of the cutter lower blade guide 78 in the roll paper transport direction (roll paper feed direction, arrow F direction). The cutter 100 is normally located at a standby position away from both ends of the roll paper 72 in the width direction, and is configured not to hinder the passage of the roll paper 72. The guide plate 120 is rotatably supported by a support portion 120b.
A torsion spring 130 is pressed against the support portion 120, and the guide plate 120 is urged upward (in the direction of arrow J) by the torsion spring 130 to be lifted. An upper stopper 103 is arranged above the guide plate 120,
The guide plate 120 comes into contact with the upper stopper 103 and stops. When the roll paper 72 forms a loop, the guide plate 120 is supported by the support portion 12
It rotates downward (the direction opposite to the arrow J direction) about 0b.

[0007]

As described above, the guide plate 120 is urged upward by the spring force of the torsion spring 130, and is rotated downward by the "strain" of the roll paper 72. For this reason, when the “strain” of the roll paper 72 is weak in a high-humidity environment, or when using a roll paper with a weak “strain” such as the second original drawing, the “stiffness” of the roll paper 120 is smaller than the spring force of the torsion spring 130. The force by which the "strain" pushes the guide plate 120 downward is weaker. For this reason, the guide plate 120 is not sufficiently lowered, and the space for forming the loop is narrowed.

In such a case, as shown in FIG. 8, although a loop is formed between the cutter lower blade guide 78 and the curl removing roller 90, the guide surface 1 of the guide plate 120 is formed.
An S-shaped loop is formed in a narrow space formed between the upper guide plate 80 and the upper guide plate 80. Thus S
When a loop in the shape of a letter is formed, the looped portion is caught by the curl removing roller 90 and the pressing roller 88 during paper feeding, and the roll paper 72 is bent into a Z shape or jammed (paper jam). May occur. In this case, the roll paper 72 does not reach the lower exit guide 67 or the upper exit guide 92, and the roll paper 72 is not conveyed to the image forming unit.

The present invention has been made in view of the above circumstances, and has as its object to provide a roll paper unit that can reliably create a space in which a predetermined amount of loop can be formed without being affected by the surrounding environment or the "strain" of roll paper. And

[0010]

According to a first aspect of the present invention, there is provided a roll paper unit for storing roll paper in an image forming apparatus having an image forming section for forming an image on roll paper. A roll paper unit provided with a paper feed mechanism for feeding rolled paper to the image forming section; (1) being disposed upstream of the image forming section in the paper feed direction and holding the fed roll paper; (2) selectively stopping at both a guide position for guiding the roll paper to the holding member and a loop forming position for creating a space in which a loop of the roll paper can be formed in front of the holding member; A guide member disposed upstream of the holding member in the sheet feeding direction; and (3) driving the guide member so that the guide member selectively stops at both the guide position and the loop forming position. That it is characterized in that it comprises a drive means.

Here, (4) the drive means stops the guide member at the guide position when the feeding of the roll paper is started, and the leading end of the roll paper is held by the holding member. The guide member may be stopped at the loop forming position when the guide member is located downstream of the holding member in the sheet feeding direction.

(5) The driving means may stop the guide member at the loop forming position in a state of waiting for the supply of roll paper.

Further, (6) the guide member is a plate-shaped member which rotates between the guide position and the loop forming position about a predetermined rotation axis, and (7) the driving means. May be connected to one end of the guide member and drive the guide member by reciprocating in a predetermined direction.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the roll paper unit of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the appearance of a copying machine in which a roll paper unit according to an embodiment of the present invention is incorporated.

An openable / closable platen cover 12 is arranged on the top surface of a copying machine (an example of an image forming apparatus according to the present invention) 10, and the platen cover 12 sends a document to a platen. Also serves as a document feeder (DF).
An operation unit 14 for inputting the number of copies and the like is arranged on the front side of the top surface. The copier 10 can selectively form an image on both cut paper and roll paper, and includes four cassettes 1 each storing a plurality of cut papers.
6, 18, 20, and 22 are provided so as to be freely inserted into and removed from the main body of the copying machine 10. Further, a roll paper unit 70 in which the roll paper is stored is incorporated in the main body of the copying machine 10 so as to be freely taken in and out. The copier 10 also includes a manual tray 23 on which small-sized recording paper such as a postcard can be placed. Further, a paper output tray 25 on which recording paper on which an image is formed is stacked is provided.

Referring to FIG. 2, a procedure for forming an image by the copying machine 10 of FIG. 1 will be described.

FIG. 2 is a schematic diagram showing an outline of the internal structure of the copying machine 10. As shown in FIG.

Below the platen cover 12 (see FIG. 1),
A document glass 24 on which a document is placed is arranged. An exposure optical system that irradiates a document and obtains an image signal carrying image information is arranged below the document glass 24. The exposure optical system includes a light source 26, a lens 28, and mirrors 30, 32, 34, 36, 38, and 40. The original placed on the original glass 24 is irradiated with light from the light source 26, and the reflected light 42 from the original is converted into an image signal by the lens 28 and the mirrors 30, 32, 34, 3
After passing through 6, 38, and 40, the light is irradiated on a photosensitive drum 44 disposed below the exposure optical system. As shown in FIG.
Has a rotating shaft 44a extending in a direction perpendicular to the paper surface of
It is rotating in the direction of arrow A. A primary charger 4 for uniformly charging the photosensitive drum 44 is provided upstream of the irradiation position where the reflected light 42 from the document is irradiated in the rotation direction of the photosensitive drum 44.
6 are arranged. After the photosensitive drum 44 is uniformly charged by the primary charger 46 to form a charged surface,
The charged surface is irradiated with the reflected light 42 from the document to form an electrostatic latent image.

A developing device 48 for developing an electrostatic latent image is disposed downstream of the irradiation position in the rotation direction of the photosensitive drum 44. An area where the photosensitive drum 44 and the developing device 48 face each other is a developing area where the electrostatic latent image is developed,
When the electrostatic latent image reaches the developing area by the rotation of the photosensitive drum 44, the developing device 48 develops the electrostatic latent image to form a toner image (developed image).

A transfer charger 5 for transferring a toner image onto recording paper is provided downstream of the developing area in the rotation direction of the photosensitive drum 44.
0 is arranged. Photosensitive drum 44 and transfer charger 50
Is a transfer area where the toner image is transferred onto the recording paper. When the toner image reaches the transfer area by rotation of the photosensitive drum 44, the toner image is transferred onto the recording paper conveyed to the transfer area. Transcribed.

The recording sheets are cassettes 16, 18, 20, and 2.
2 and roll paper unit 70 and are conveyed to the transfer area. In transporting the recording paper to the transfer area, for example, the cut paper 16a sent out from the cassette 16 or the like by the paper feed roller 16b is caused to stand by in a state where the leading end of the cut paper 16a contacts the registration roller 54 to form a loop. The recording paper is conveyed to the transfer area at the timing when the toner image reaches the transfer area.

The recording paper onto which the toner image has been transferred is separated from the photosensitive drum 44 by a separation charger 56, is conveyed to a conveyor belt 58 rotating in the direction of arrow B, and reaches a fixing unit 60. The toner image is fixed on the recording paper. After the toner image is fixed on the recording paper, the recording paper is discharged to a paper discharge tray 25 from a paper discharge port (not shown). In addition,
The residual toner remaining on the photosensitive drum 44 after the transfer is removed from the photosensitive drum 44 by the cleaning device 64. Further, the residual charges remaining on the photosensitive drum 44 are discharged by a discharge lamp (not shown). As a result, the photosensitive drum 44 is ready for the next image formation.

The roll paper unit 70 will be described with reference to FIG.

FIG. 3 is a schematic diagram showing a roll paper unit 70 incorporated in the main body of the copying machine 10. In this figure, the same components as those in FIG. 2 are denoted by the same reference numerals.

The roll paper 72 is formed by fixing both ends of a spool 74 on which the roll paper 72 is set to a spool holder 76 so as to be rotatable.
0. The roll paper 72 accommodated in the roll paper unit 70 waits until the start of paper supply with the leading end 72 a thereof being sandwiched between the pressure roller 84 and the paper supply roller 86.

When the supply of the roll paper 72 is started, the roll paper 72 is supplied to the cutter lower blade guide plate 78, the guide plate 80, and the plate-like guide member (the guide member according to the present invention) disposed above the roll paper 72. 87), and is nipped between a press roller 88 and a curl removing roller (feed roller) 90. The press roller 88 is made of metal, and the curl removing roller 90 is a sponge wound around the outer peripheral surface. By rotating the paper feed roller 86 and the curl removing roller 90, the roll paper 72 is transported in the paper feed direction. Thereafter, the guide member 87 rotates to the loop forming position and stops as described later.

With the guide member 87 stopped at the loop forming position, a loop of the roll paper 72 is formed, and the loop of the roll paper 72 is held until the cutter 100 finishes cutting the roll paper 72. Paper feeding is performed. Note that the cutter 100 is disposed downstream of the cutter lower blade guide 78 in the roll paper feeding direction. This cutter 100
Usually, it is located at a standby position separated from both ends in the width direction of the roll paper 72, and is configured not to hinder the passage of the roll paper 72. The holding roller 88 and the curl removing roller 90 constitute a holding member according to the present invention.

Referring to FIGS. 4 to 6, guide member 8
7 will be described.

FIG. 4 is a schematic diagram showing a state where the guide member 87 is stopped at the loop forming position, and FIG. 5 is a schematic diagram showing a state where the guide member 87 is stopped at the guide position. FIG. 6 is a schematic diagram illustrating a state in which the roll paper 72 forms a loop. In these figures, FIGS. 2 and 3
The same reference numerals are given to the same components as those of the above. Also, since each component is shown enlarged,
Some of the same components as those in FIGS. 2 and 3 have slightly different shapes.

The guide member 87 includes a guide surface 87a disposed upstream of the press roller 88 and the curl removing roller 90 in the paper feeding direction, an arm portion 87c connected to the guide surface 87a and extending in the paper feeding direction, and an arm portion. And a supporting portion (which is an example of a predetermined rotating shaft according to the present invention) 87b that rotatably supports 87c. The arm 87c rotates between the loop forming position shown in FIG. 4 and the guide position shown in FIG. 5 with the support 87b as the center axis of the rotation.

When the arm portion 87c is located at the loop forming position, a space where a loop of the roll paper 72 can be formed is created above the guide surface 87a. On the other hand, when the arm portion 87c is located at the guide position, the guide surface 87a
The roll paper 72 is pressed by the pressing roller 8
8 and the curl removing roller 90. Further, at the guide position, the guide surface 87a is in contact with the upper stopper 103, whereby the guide member 87 stops at the guide position. On the other hand, at the loop forming position, the back surface of the guide surface 87a is in contact with the lower stopper 102, whereby the guide member 87 stops at the loop forming position.

A guide member 8 is provided below the arm 87c.
A solenoid (which is an example of a driving means according to the present invention) 101 for rotating the rotating member 7 is disposed. This solenoid 1
01 has a plunger 101a which reciprocates in the direction of arrow C. The tip of the plunger 101a is connected to one end of the arm 87c in the sheet feeding direction. In the roll paper feed standby state shown in FIG. 4, power is not supplied to the solenoid 101, and the guide member 87 is moved to the guide surface 87a.
Is in contact with the lower stopper 102 and stopped by the spring force of the plunger spring 101b with its own weight.

An outlet upper guide 92 and an outlet lower guide 67 are disposed slightly downstream of the curl removing roller 90 in the sheet feeding direction. On the exit side of the exit upper guide 92 and the exit lower guide 67, an exit sensor 110 for detecting the roll paper 72 is disposed. This exit sensor 110
It comprises a support portion 110a serving as a rotation axis, an arm portion 110b rotatably supported by the support portion 110a, and a photo sensor portion 110c. As shown in FIG. 6, the leading end of the roll paper 72 guided by the upper exit guide 92 and the lower exit guide 67 pushes the arm 110b, so that the arm 110b is turned around the support 110a. The roll paper 72 rotates in the direction D, and the photo paper 110c detects the roll paper 72.

When a copy start button (not shown) is turned on and a paper feed command is issued in a paper feed standby state of the roll paper 72 shown in FIG. 4, power is supplied to the solenoid 101, and
The plunger 101a is retracted. Accordingly, the guide surface 87a of the guide member 87 rotates upward (in the direction of the arrow J), comes into contact with the upper stopper 103, and stops.

Thereafter, the paper feed roller 86 starts to rotate, and the roll paper 72 is fed in the paper feed direction (arrow F direction). The leading end 72a of the roll paper 72 is guided by the curl removing roller 90 by the guide surface 87a.
The paper is fed while being held by the press roller 88.

When the leading edge 72a of the roll paper 72 is detected by the exit sensor 110, the rotation of the curl removing roller 90 stops, but the paper feeding roller 86 continues to rotate. Thereby, the loop of the roll paper 72 starts to be formed. Simultaneously with the above detection, the power supply to the solenoid 101 is also stopped, and the guide member 87 rotates downward and stops at the loop forming position, and a space is formed above the guide surface 87a where a predetermined amount of loop can be formed. . Therefore, the space above the guide surface 87a is sufficiently wide, and a predetermined amount of loop can be formed. In this manner, a space in which a predetermined amount of loops can be formed is created regardless of the strength of the "strain" of the roll paper 72, so that a space in which a predetermined amount of loops can be formed can be reliably created.

As the paper feed roller 86 rotates without the curl removing roller 90 rotating, as shown in FIG. 6, in the area from the downstream side in the paper feeding direction with respect to the cutter lower blade guide 78 to the curl removing roller 90, as shown in FIG. A loop is formed. When the loop amount reaches a predetermined amount, the curl removing roller 90 starts to rotate again, and the paper is fed to the image forming unit while keeping the loop amount constant until the roll paper 72 is cut by the cutter 100. The loop during paper passing expands downward from the downstream side in the paper feeding direction with respect to the cutter lower blade guide 78, and the roll paper 72 enters the curl removing roller 90 while contacting the guide surface 87a. In the above-described embodiment, the solenoid 101 is used to rotate the guide member 87. However, a gear mechanism or a mechanism combining a motor and a belt may be used instead of the solenoid 101.

[0039]

As described above, according to the roll paper unit of the present invention, the guide member is driven by the driving means so as to be selectively stopped at both the guide position and the loop forming position. "Koshi" of environment and roll paper
A space in which a predetermined amount of loop can be formed without being affected by the above. Therefore, even if the roll paper is fed in a high-humidity environment or a roll paper such as the second original drawing, the roll paper is
It can be prevented from being bent in a character shape and from being jammed due to the bent.

Here, when the driving means starts feeding the roll paper, the guide member is stopped at the guide position, and the leading end of the roll paper is clamped by the clamping member so that the paper is fed more than the clamping member. When the guide member is stopped at the loop forming position when it is located on the downstream side in the direction, the guide member has a relatively simple configuration.

In the case where the driving means is in a state of waiting for the supply of roll paper, the mechanism of the driving means can be further simplified if the guide member is stopped at the loop forming position.

Further, the guide member is a plate-like member which rotates between a guide position and a loop forming position about a predetermined rotation axis, and a driving means is connected to one end of the guide member. When the guide member is driven by reciprocating in a predetermined direction, the configuration of the guide member and the driving means can be made relatively simple.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an appearance of a copying machine in which a roll paper unit according to an embodiment of the present invention is incorporated.

FIG. 2 is a schematic diagram showing an outline of an internal structure of the copying machine.

FIG. 3 is a schematic diagram illustrating a roll paper unit incorporated in a main body of the copying machine.

FIG. 4 is a schematic diagram showing a state where a guide member is stopped at a loop forming position.

FIG. 5 is a schematic diagram showing a state where a guide member is stopped at a guide position.

FIG. 6 is a schematic diagram showing a state in which the roll paper forms a loop.

FIG. 7 is an enlarged schematic view of a main part of a conventional roll paper unit, showing a state in which the leading end of the roll paper is guided by a curling roller.

FIG. 8 shows how insufficient loops are formed;
It is the schematic diagram which expanded the principal part of the conventional roll paper unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Copier 70 Roll paper unit 72 Roll paper 87 Guide member 88 Pressing roller 90 Curling roller 101 Solenoid

Claims (4)

[Claims] An image forming apparatus provided with an image forming unit for forming an image on roll paper, a roll containing roll paper and a paper feed mechanism for feeding the stored roll paper to the image forming unit. In the paper unit, a holding member disposed upstream of the image forming unit in the paper feeding direction and holding the fed roll paper, a guide position for guiding the roll paper to the holding member, and the holding member Selectively stop at both loop forming positions to create a space where a loop of roll paper can be formed before
A guide member disposed upstream of the holding member in the paper feeding direction, and a driving unit for driving the guide member so that the guide member selectively stops at both the guide position and the loop forming position. And a roll paper unit comprising: 2. The driving device according to claim 1, wherein when the sheet feeding of the roll paper is started, the guide member is stopped at the guide position, and a leading end portion of the roll paper is held by the holding member. 2. The roll paper unit according to claim 1, wherein the guide member is stopped at the loop forming position when the guide member is located on the downstream side in the paper feeding direction. 3. 3. The apparatus according to claim 1, wherein the drive unit stops the guide member at the loop forming position in a state of waiting for the supply of the roll paper. Roll paper unit as described. 4. The guide member is a plate-like member that rotates between a guide position and the loop forming position about a predetermined rotation axis, and the driving unit is configured to rotate the guide member. The guide member is driven by reciprocating in a predetermined direction after being connected to one end, and wherein the guide member is driven.
The roll paper unit according to the above.