JP2011057421A - Device for carrying roll paper and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively achieve improvement in productivity and holding of a stopping position, by performing highly accurate low speed carrying and high speed carrying except for recording on roll paper by a single motor and a simple transmission mechanism. <P>SOLUTION: In the device for carrying a roll paper, for carrying the roll paper 12 while being sandwiched between a register roller 8 and a pressurizing roller 6 while applying back tension, a small diameter belt gear 16, an intermediate diameter belt gear 20, a large diameter belt gear 21, a first belt transmission system of the low reduction gear ratio and a second belt transmission system of the high reduction gear ratio constituted of first and second belts 22 and 23, are arranged between a rotary shaft 13a of one register motor 13 and the register roller 8. A plurality of tensioners 24 and 25 are arranged to be displaceable to a position for individually applying tension to the belts 22 and 23 of the belt transmission system of its respective systems and a position for relaxing the belts 22 and 23. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a roll paper conveying device provided in an image forming apparatus such as a printer or a plotter for recording information such as characters and images on roll paper, a copying machine, a facsimile machine, or a complex machine thereof, and the like. The present invention relates to an image forming apparatus including

There is an image forming apparatus such as a printer or a plotter or the like that records information such as characters and images on the roll paper (paper) using a roll paper in which a long sheet of a certain width is wound into a roll. It is often used as an output device of a host device such as a computer.

  In such an image forming apparatus, the roll paper held by the paper holder is pulled out and fed, and is conveyed at a constant speed or intermittently at a predetermined timing by a high-precision conveyance roller (generally referred to as “registration roller”). The information is recorded (image formation) on the roll paper (paper). Thereafter, the portion where a series of image formation has been completed is discharged, the roll paper is conveyed until the trailing edge reaches the cutter position, cut by the cutter, and then the remaining roll paper is pulled back until the leading edge reaches a predetermined recording standby position. . Further, a back tension is applied by applying a load in the conveyance direction so that the roll paper does not loosen during conveyance.

  For example, in Patent Document 1, a back tension mechanism such as a return spring is applied to a spool to constantly apply a small back tension, and a single transport motor feeds roll paper and a constant speed during recording by a transport roller. There is disclosed a sheet conveying apparatus of a recording apparatus that can perform conveyance and return conveyance after recording.

  In Patent Document 2, one DC motor is commonly used for feeding roll paper by a paper feed roller and high-speed conveyance by a constant speed conveyance roller (referred to as a grid roller). There has been disclosed a paper sheet conveying apparatus in which high-precision conveyance during alignment and recording is performed by driving a grid roller by a stepping motor.

  However, the sheet conveying apparatus described in Patent Document 1 drives a conveying roller via a belt transmission mechanism by a single conveying motor, and via another belt transmission mechanism, a clutch, a gear train, a torque limiter, and the like. A complicated mechanism for driving a spool for holding the roll paper increases the cost. In addition, since the transport motor will rotate in the forward and reverse directions but the driving speed will be constant, the transport of the roll paper after recording to the cutting position and the subsequent return transport are the same speed as during recording, and the start of the next recording is slow. Therefore, productivity is bad. When trying to convey at high speed except during recording, it is necessary to control to increase the rotation speed of the conveyance motor, which not only complicates the motor control circuit but also increases power consumption.

In addition, since the transport apparatus described in Patent Document 2 can switch between the transport speed at the time of recording roll paper and the transport speed at other times, the productivity can be improved, but the grid corresponding to the registration roller can be improved. Since two different types of motors and two electromagnetic clutches are used to drive the roller, there are still problems that the cost increases and the power consumption increases.
Further, in any of the transport devices, since the back tension in the return direction applied to the roll paper is not particularly considered for holding the stop position in the transport stop state, the roll paper is stopped at a predetermined recording standby position. However, there is also a problem that the stop position cannot be kept accurately and the recording start position may be shifted unless the position is adjusted again at the start of recording.

  The present invention has been made to solve such a problem. In the roll paper transport apparatus and the image forming apparatus including the roll paper as described above, high-precision constant speed transport or intermittent operation during the recording of the roll paper is provided. The transfer and high-speed transfer at other times can be performed with a single motor and a simple transmission mechanism, improving productivity and maintaining the stop position at low cost, and reducing power consumption. For the purpose.

  In order to achieve the above object, a roll paper transport device according to the present invention is configured to rotate one resist motor in order to achieve the above object. A plurality of belt transmission systems having different reduction ratios are provided between the shaft and the registration roller, and a position for individually applying tension to the belts of the plurality of belt transmission systems and a position for relaxing the belt. A plurality of displaceable tensioners are provided.

When the roll paper is conveyed, tension is selectively applied only to one of the belts of a plurality of belt transmission systems having different reduction ratios by the tensioner, and when the conveyance is stopped, the plurality of belts are transmitted by the tensioner. A belt is applied to two or more belts of a belt transmission system.

The plurality of belt transmission systems with different reduction ratios may be a first belt transmission system with a reduced speed ratio and a second belt transmission system with a high reduction ratio.
Further, the registration motor is a stepping motor, a small-diameter belt gear is fixed to the rotating shaft of the stepping motor, a medium-diameter belt gear and a large-diameter belt gear are fixed coaxially with the registration roller, and the small-diameter belt gear is A first timing belt is stretched between the medium diameter belt gear and the first belt transmission system having the above reduction speed ratio, and a second timing belt is interposed between the small diameter belt gear and the large diameter belt gear. The second belt transmission system having the high reduction ratio can be formed by stretching.

  An image forming apparatus according to the present invention includes the above-described roll paper transport device and a recording unit that records information such as characters and images on the roll paper transported by the roll paper transport device.

  A roll paper transport device and an image forming apparatus provided with the same according to the present invention provide a single motor and simple transmission for high-precision constant speed transport or intermittent transport during roll paper recording and high-speed transport at other times. Since it can be performed by a mechanism, productivity can be improved and the stop position can be maintained at low cost, and power consumption can be reduced.

1 is an overall configuration diagram showing an embodiment of an image forming apparatus provided with a roll paper transport device according to the present invention. It is a front view which shows the low-speed conveyance state of one Example of the roll paper conveying apparatus by this invention. It is a front view which similarly shows the high-speed conveyance state. It is a front view which similarly shows the stop holding state.

Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.
FIG. 1 is an overall configuration diagram showing an embodiment of an image forming apparatus provided with a roll paper transport device according to the present invention.
The image forming apparatus shown in FIG. 1 is an inkjet printer or the like, and includes a box-shaped roll paper supply unit 30 and a recording unit 40 mounted thereon.

The recording unit 40 includes a carriage stay 2 on which the carriage 1 is mounted, a cutter 3, a suction stay 4, a suction fan 5, a pressure roller 6, a pressure mechanism 7, a registration roller 8, and a movable guide plate biased by a spring 9a. 9 etc. are provided.
The roll paper supply unit 30 includes three roll holders 32 for holding a roll of roll paper 12 in which a long paper with a certain width is wound in a roll shape in a casing 31, three paper feed rollers 11, A sheet conveying path 33 having three branch paths 33a, 33b, and 33c for guiding the roll sheet fed by each sheet feeding roller 11 and a plurality of sets of intermediate rollers 10 provided in the conveying path are provided.

  The flow of the paper is such that the roll paper 12 is fed from one of the three roll holders 32 of the roll paper supply unit 30 by the paper feed roller 11, passes through the paper transport path 33 and the intermediate roller 10, and then the recording unit 40. To supply. In the recording unit 40, when the supplied roll paper (hereinafter also referred to as “paper”) reaches the registration roller 8, the paper is sandwiched between the pressure roller 6 and tension is applied to the paper by the movable guide plate 9. The registration roller 8 rotates at a required timing while the pressure 6 is pressed by the pressure mechanism 7, and the sheet is conveyed at a constant speed or intermittently along the suction stay 4.

The paper conveyed by the registration roller 8 is mounted on the carriage stay 2 and information is recorded (printed) by, for example, an ink jet recording head of the carriage 1 that reciprocates in the main scanning direction which is a direction perpendicular to the paper surface in FIG. Is done. During the recording, the sheet is sucked by the suction stay 4 by the suction fan 5 and the flatness is maintained. Note that the paper transport direction is the sub-scanning direction.
The recording head provided on the carriage 1 has been described as an ink jet recording head, but is not limited to this, and various other recording heads such as a laser beam method, a thermal transfer method, a thermal method, and a wire dot method can be used. It may be adopted.

  When the recording of a series of information is completed, the registration roller 8 rotates in the same direction (forward rotation) at a higher speed than at the time of recording, and the paper on which the information is recorded is cut by the cutter 3 at the rear end portion of the recorded portion. The paper is transported at a speed higher than that at the time of recording until reaching the position, and then the rear end portion is cut by the cutter 3, and the cut paper is discharged from the paper discharge guide 41 onto the paper discharge tray 42 by a paper discharge roller (not shown). The paper is ejected. After the paper is cut by the cutter 3, the registration roller 8 rotates reversely at high speed, and the remaining roll paper is pulled back until the leading edge comes to the next recording start position (recording standby position) and stopped. Each stop position of the paper is detected by a photoelectric sensor or the like (not shown).

  A back tension mechanism such as a return spring is provided in the spool of each roll holder 32 of the roll paper supply unit 30, and the back tension is always applied in the direction of pulling back the roll paper 12 so that the roll paper 12 does not loosen during conveyance. In addition, rewinding is possible when the registration roller 8 is pulled back by reverse rotation. Therefore, each of the paper feed rollers 11 and the intermediate roller 10 is slightly opened except when rotating in the paper feed direction, or is freely rotatable in the reverse direction by a one-way clutch, thereby freeing the roll paper 12.

  Next, an embodiment of a roll paper conveyance device including the registration roller 8 and the pressure roller 6 provided in the image forming apparatus will be described with reference to FIGS. 2 to 4 are schematic front views showing different states of the roll paper transport device.

2 to 4, a small-diameter belt gear 16 is fixed to a rotating shaft 13a of a registration motor 13 that is a stepping motor. The belt gear 16 has tooth belt-like irregularities for the timing belt formed in two steps at intervals in the axial direction on the outer peripheral surface.
On the other hand, on the shaft 8a of the registration roller 8, a medium-diameter belt gear 20 is located on one side (front side in FIGS. 2 to 4) with the registration roller 8 in between, and the other side (rear side in FIGS. 2 to 4). ) Has a large-diameter belt gear 21 fixed thereto. Toothed irregularities for timing belts are also formed on the outer peripheral surfaces of the belt gears 20 and 21, respectively.

  A first belt 22 is stretched between the small-diameter belt gear 16 and the medium-diameter belt gear 20 to form a first belt transmission system with a reduced speed ratio. Further, a second belt 23 is stretched between the small-diameter belt gear 16 and the large-diameter belt gear 21 to constitute a second belt transmission system having a high reduction ratio. Further, a first tensioner 24 that applies tension to the first belt 22 in the vicinity of the intermediate portion of the first belt 22 is provided so as to be movable in the directions indicated by arrows a and b, and the intermediate portion of the second belt 23 is provided. A second tensioner 25 that applies tension to the second belt 23 is provided so as to be movable in the directions indicated by arrows c and d.

Both the first belt 22 and the second belt 23 are timing belts, and tooth-like irregularities that mesh with the tooth-like irregularities on the outer peripheral surfaces of the belt gear 16 and the belt gear 20 or 21 are formed on the inner surfaces, respectively. Yes. The “tensioner” is also referred to as a “tension roller”.
In this roll paper transport device, when the first tensioner 24 moves in the direction indicated by the arrow a, tension is applied to the first belt 22 and the first belt transmission system becomes effective. Further, when the second tensioner 25 moves in the direction indicated by the arrow c, tension is applied to the second belt 23, and the second belt transmission system becomes effective.

  FIG. 2 shows a low-speed conveyance state, in which the second tensioner 25 moves in the direction indicated by the arrow c, tension is applied to the second belt 23, the second belt transmission system becomes effective, and the first tensioner 24 moves in the direction of the arrow. At the position moved in the direction b, the first belt 22 is relaxed and the first belt transmission system is disabled.

  This is a roll paper conveyance state at the time of recording, and the rotation of the registration motor 13 in the direction indicated by the arrow P is highly reduced by the second belt transmission system including the small-diameter belt gear 16, the second belt 23, and the large-diameter belt gear 21. Therefore, the registration roller 8 rotates at a low speed in the direction indicated by the arrow Q, and the roll paper 12 sandwiched between the pressure roller 6 is moved in the direction indicated by the arrow A at a speed matching the recording speed. Transport at constant speed or intermittently. At this time, the medium-diameter belt gear 20 also rotates together with the registration roller 8, but the first belt 22 is loose and slips and does not rotate.

  FIG. 3 shows a high-speed conveyance state, the second tensioner 25 moves in the direction indicated by the arrow d, the second belt 23 relaxes, the second belt transmission system becomes invalid, and the first tensioner 24 moves in the direction of the arrow. Since the first belt 22 is moved in the direction a and tension is applied to the first belt 22, the first belt transmission system is effective.

  This is a roll paper conveyance state after the recording is completed, and the rotation of the registration motor 13 in the direction indicated by the arrow P is caused by the first belt transmission system according to the small diameter belt gear 16, the first belt 22 and the medium diameter belt gear 20. Since it is transmitted to the registration roller 8 at a low reduction ratio, the registration roller 8 rotates at a high speed, and the roll paper 12 sandwiched between the pressure roller 6 is conveyed at a constant speed in the direction of arrow A at a higher speed than during recording. Or intermittent conveyance. At this time, the large-diameter belt gear 21 also rotates together with the registration roller 8, but the second belt 23 is loosened and therefore slips and does not rotate.

  Even when the recorded portion of the roll paper 12 is cut and then pulled back to the recording standby position, if the rotation direction of the registration motor 13 is reversed in this high-speed conveyance state, the rotation is caused by the first belt transmission system. Since it is transmitted to the registration roller 8 at a low reduction ratio and the registration roller 8 rotates at high speed in the direction opposite to the arrow Q, the roll paper 12 can be conveyed at high speed in the direction of arrow B and pulled back in a short time.

  FIG. 4 shows a conveyance stop holding state, and the position where the first tensioner 24 and the second tensioner 25 apply tension to the first belt 22 and the second belt 23, respectively, when the rotation of the registration motor 13 is stopped. Thus, both the first belt transmission system and the second belt transmission system are effective. Since the first belt transmission system and the second belt transmission system have different speed reduction ratios, a braking force that prevents rotation is applied to each other, and even if the roll paper 12 tries to return to the direction indicated by the arrow B by back tension, Since the roller 8 does not rotate and the roll paper 12 is sandwiched between the registration roller 8 and the pressure roller 6, the roll paper 12 does not move and is held at the stop position during the stop period.

  Thus, by having two series of belt transmission systems of high reduction ratio and reduction speed ratio, only the belt transmission system of high reduction ratio is effective at low speed conveyance, and only the reduction transmission ratio belt transmission system is at high speed conveyance. If is enabled, the roll paper transport speed can be switched by only moving the tensioner with one motor. Also, when the conveyance is stopped, tension is applied to both the belts of the high reduction ratio belt transmission system and the belt transmission system of the reduction speed ratio to make them effective, so that the braking force is applied to keep the paper in the stopped holding state. be able to.

  According to this embodiment, since there is only one registration motor, it is not necessary to switch and control its rotation speed, and it is only necessary to perform forward / reverse rotation and stop at a constant speed, so the configuration of the control circuit is simple. Since it is not necessary to rotate the registration motor at high speed, less power is consumed.

  In addition, the first tensioner 24 and the second tensioner 25 are in a position where the first belt 22 and the second belt 23 are tensioned by being constantly urged by the springs in the directions indicated by the arrows a and c, respectively. The first belt transmission system is disabled by moving only the first tensioner 24 in the direction of arrow b by the solenoid during low speed conveyance, and only the second tensioner 25 is moved in the direction of arrow d by the solenoid during high speed conveyance. If the second belt transmission system is made invalid by moving it, only one solenoid needs to be energized only when the roll paper 12 is conveyed, so that power consumption can be further reduced.

  In this embodiment, a stepping motor is used as a registration motor, and a timing belt and a belt gear are used for each belt transmission system to enable high-precision intermittent driving without slipping. Instead, a DC motor or the like may be used as the registration motor, an ordinary belt having no tooth-like irregularities may be used for each belt transmission system belt, and a belt roller may be used instead of the belt gear.

  In addition, three or more belt transmission systems with different reduction ratios are provided between one conveyance motor (registration motor) and conveyance roller (registration roller), and each belt tensioner moves to at least three types of conveyance speeds. It can also be made switchable. In this case as well, at the time of stopping the conveyance, if the belt transmission systems of at least two systems are made effective, the braking force can be applied to hold the stop position.

The roll paper transport device according to the present invention can be applied to a recording device such as a printer or plotter for recording information such as characters and images on the roll paper, an image forming apparatus such as a copying machine, a facsimile machine, or a complex machine thereof. .

1: Carriage 2: Carriage stay 3: Cutter 4: Suction stay 5: Suction fan 6: Pressure roller 7: Pressure mechanism 8: Registration roller 9: Movable guide plate 10: Intermediate roller 11: Paper feed roller 12: Roll paper 13: Registration motor 16: Small-diameter belt gear 20: Medium-diameter belt gear 21: Large-diameter belt gear 22: First belt (for belt transmission system with reduced speed ratio)
23: Second belt (for belt transmission system with high reduction ratio)
24: First tensioner (for belt transmission system with reduced speed ratio)
25: Second tensioner (for belt drive system with high reduction ratio)
30: Roll paper supply unit 31: Housing 32: Roll holder 33: Paper transport path 33a, 33b, 33c: Branch path 40: Recording unit 41: Paper discharge guide 42: Paper discharge tray

JP 2006-248863 A JP-A-8-59041

Claims (4)

In a roll paper transporting device that sandwiches and transports roll paper between a registration roller and a pressure roller while applying back tension,
A plurality of belt transmission systems having different speed reduction ratios are provided between the rotation shaft of one registration motor and the registration roller, and a position for individually applying tension to the belts of the plurality of belt transmission systems, and Provide multiple tensioners that can be displaced to the position where the belt is relaxed,
When transporting the roll paper, the tensioner selectively applies tension to only one of the belts of a plurality of belt transmission systems having different speed reduction ratios by the tensioner. A roll paper conveying apparatus characterized in that tension is applied to two or more belts of a belt transmission system.   2. The roll paper conveying apparatus according to claim 1, wherein the plurality of belt transmission systems having different reduction ratios are a first belt transmission system having a reduced speed ratio and a second belt transmission system having a high reduction ratio. .   The registration motor is a stepping motor, a small-diameter belt gear is fixed to the rotation shaft of the stepping motor, an intermediate-diameter belt gear and a large-diameter belt gear are fixed coaxially with the registration roller, and the small-diameter belt gear and the A first timing belt is stretched between a medium-diameter belt gear and the first belt transmission system having the reduced speed ratio is configured, and a second belt is interposed between the small-diameter belt gear and the large-diameter belt gear. The roll paper conveying device according to claim 2, wherein a timing belt is stretched to constitute the second belt transmission system having the high reduction ratio.   A roll paper transport device according to any one of claims 1 to 3, and a recording unit that records information such as characters and images on the roll paper transported by the roll paper transport device. Image forming apparatus.

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