JPH0826542A - Continuous paper transport mechanism - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a continuous paper printing apparatus, and more particularly to a continuous paper transport mechanism for stably transporting continuous paper, and a continuous paper transport mechanism capable of absorbing unnecessary tension generated in continuous paper. For the purpose of providing. A continuous paper transport mechanism including a tractor 3 for transporting the continuous paper 1 upstream of a photosensitive drum 4 arranged in a transport path of the continuous paper 1, wherein a continuous paper transport mechanism is provided between the photosensitive drum 4 and the tractor 3. In addition, a conveyance roller 71 that conveys and drives the continuous paper at the same speed as the conveyance speed of the tractor 3 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous paper printing apparatus,
In particular, it relates to a continuous paper transport mechanism that stably transports continuous paper.

With the recent increase in speed and space saving of printing apparatuses, high print quality is required. Therefore, it has a paper feed mechanism that feeds continuous paper with a paper feed tractor and pulls it with a scuff roller, and a toner image formed on a photoconductor is formed by a transfer section provided between the paper feed tractor and the scuff roller. 2. Description of the Related Art There is provided a printing apparatus in which a transfer guide is closely attached to a continuous sheet to transfer the image and the image is fixed to a fixing device.

In the continuous paper conveying process in this printing apparatus, it is desired to develop a means for preventing a paper jam generated in the conveying mechanism of the paper feed tractor due to a change in the paper width due to a change in humidity.

[0004]

2. Description of the Related Art FIG. 3 is a block diagram showing an example of a conventional electrophotographic continuous paper printing apparatus. In order to make the description of the configuration and operation easier to understand, the same parts will be denoted by the same reference symbols throughout the drawings, without redundant description.

In FIG. 3, reference numeral 1 is a continuous paper, which is pulled out from the hopper 2 in the carrying direction by a tractor 3 as an upstream paper feeding means. Reference numeral 4 denotes a photosensitive drum that forms a toner image. Since static electricity for attracting the toner image is applied to the surface of the photosensitive drum, the continuous paper 1 is also attracted by the static electricity, and as the photosensitive drum 4 rotates. The continuous paper 1 receives a load force in the transport direction. On the downstream side of the photosensitive drum 4, a scuff roller 7 is provided as a downstream paper feeding means.

The continuous paper 1 is fed between the photosensitive drum 4 and the transfer section 5, and the toner image formed on the surface of the photosensitive drum 4 at the transfer section 5 is transferred to the continuous paper 1 and then transferred to the fixing section 6. The paper is sent in, guided to the scuff roller 7, and collected by the stacker 8 to form a straight paper conveyance path.

Although various known means for forming a toner image are arranged around the surface of the photosensitive drum 4,
The description is omitted because it is not directly related to the present invention. 9
Is a control unit including a power source and the like for controlling the respective components by a higher-level control device (not shown), and 10 is a rocker that houses the respective components.

The control unit 9 increases the conveyance speed in the order of the tractor 3, the photosensitive drum 4, and the scuff roller 7 in order to prevent the occurrence of the slack of the paper on the paper conveyance path. FIG. 4 shows a schematic front view of a conventional tractor and a layout diagram of a photosensitive drum and continuous paper. In the figure, 1a and 1b are continuous paper 1
Are feed holes continuously provided at equal intervals along both side edges of the. The tractor 3 is composed of a pair of tractors 3a and 3b for feeding the continuous paper 1 on both side edges thereof.
And a pin belt 31a and 31b of the pins 32a ₁ ~32a ₄ and 32b ₁ ~32b ₄ to respectively engage planted in 1a and 1b. 32a and 32b show the pin rows of each pin 32a ₁ ~32a ₄ and 32b ₁ ~32b _4.

By the tractor drive shaft 34, the pin row 32a,
By driving 32b, continuous paper is fed in the direction of arrow A in the figure. Also, 33a and 33b are paper retainers that can be opened and closed, 35 is a guide shaft, and 36a and 36b are for locking a pair of tractors 3a and 3b at arbitrary positions in the width direction of the continuous paper 1 on the guide shaft. It is a lock knob of.

In the conventional apparatus, the pin row 32a of the tractor 3a and the pin row 32b of the tractor 3b are arranged in parallel with the feed holes 1a and 1b of the continuous paper 1. That is, the pin intervals of the opposing pins, for example, the pins 32a ₁ and 32b ₁ , 32a ₄ and 32b ₄ are equal.

Thus, in the conventional apparatus, the continuous paper 1
When setting the tractor on the tractor 3, generally, first, the tractor
Secure 3a with the lock knob 36a, and press the paper retainers 33a and 33b.
Open, and insert the feed holes 3a and 3b of the continuous paper 1 into the pin rows 32a,
Engage each pin of 32b, and then press the paper retainers 33a and 33b.
Close. Next, the tractor 3b is lightly pulled in the direction of the arrow B so that the continuous paper 1 is not loosened in the width direction, and the position is fixed by the lock knob 36b while keeping tension in the width direction of the continuous paper 1. 1c indicates a paper center line.

[0012] Although this in complete sets of the continuous sheet 1, the pin array 32a in this state, the relationship between the pin and the feed holes 3a and 3b and 32b, all of the pins 32a ₁ ～32A the left pin rows 32a ₄ the left end is in contact with the left end of the feed holes 1a, all the right end of the pin 32b ₁ ～32B ₄ in the right pin rows 32b would contact with the right end of the feed hole 1b.

That is, the center of the pin deviates from the center of the feed hole. Therefore, if the continuous paper 1 shifts to the left or right even slightly, the pin easily comes off the feed hole. The state in which the pin is disengaged from the feed hole is referred to as "passing through the sheet hole", and in this state, the continuous paper 1 cannot be fed stably. To solve this drawback, the following mechanism has been developed.

FIG. 5 is an engagement operation diagram of a pin row and a feed hole of a conventional example, and there are (a) expansion type and (b) swing type.
(A) The expansion type is improved so that the interval between the facing pins of the pair of pin rows 32a and 32b of the tractor becomes gradually wider from the entrance side of the continuous paper 1 toward the discharge side. That is, when the distance between the pins on the entrance side of the continuous paper 1 is W ₂ and the distance between the pins on the discharge side is W ₁ , the parallelism of the pin rows is changed so that W ₁ > W _2. Is held by the lock knobs 36a and 36b and fixed to the guide shaft 35.

With this mechanism, even if the pin row is engaged with the feed hole when the continuous paper is set, and then the paper is stretched in the width direction and locked, the center of the pin and the center of the feed hole at the entrance side of the continuous paper 1 The paper feed will be stable because of the matching.

(B) In the case of the swing type, the pair of tractors 3a and 3b can swing independently left and right with respect to the paper feeding direction of the continuous paper 1 around the lock portion of the guide shaft 35. It is a mechanism. That is, when the distance W between the feed holes changes in a direction in which it spreads due to factors such as humidity changes during continuous paper feeding, the pair of tractors 3a and 3b are respectively provided with arrows E around the lock portion.
And F direction. On the contrary, when the distance W between the feed holes changes in the direction of contraction, the pair of tractors 3a and 3b rotate in the directions of arrow G and H around the vicinity of the lock portion, respectively.

Further, depending on the paper width change state of the continuous paper 1, only one of the tractors rotates. As a result, the pin row of the tractor can follow the change of the paper width due to the change of humidity.

[0018]

In FIG. 4, since the photosensitive drum 4 and the scuff roller 7 (not shown) convey the continuous paper 1 uniformly by applying tension in the conveying direction,
A tension as shown by an arrow C is generated on the continuous paper 1 immediately before the photosensitive drum 4.

Further, in the tractor 3, since the paper is conveyed while applying tension in the width direction by the several pin rows 32a and 32b which engage with the feed holes 1a and 1b of the continuous paper 1, it is particularly wide. For continuous paper, etc., start from the paper edge to the paper center line.
Force is generated in the direction toward 1c (arrows D and D ').

Due to the synergistic effect of the tension in the arrow C direction and the tension in the arrow D, D'direction, when the distance between the feed holes in the width direction of the continuous paper 1 changes in the direction of contraction due to factors such as humidity change, the feed holes 1a , 1b the position of each pin engaged to the outside of the individual feed holes, and if the tension exceeds the limit, the feed holes 1a, 1b will be worn,
There is a problem that the skew and the deviation of the sheet from the pin row of the tractor 3 occur.

Also in the improved configuration of FIG. 5A, both lock knobs 36a and 36b are locked when the continuous paper 1 is set on the pair of tractors 3a and 3b, so that the width of the paper due to humidity change or the like. Along with the change, a force may be generated particularly in the direction from the side edge of the paper to the paper center line 1c (arrows D and D ′) as shown in FIG.

Also in FIG. 5B, the lock knobs 36a and 36b are provided.
Both are locked. Further, since the change in the pin interval in the direction connecting the rotation center points near the lock knobs 36a and 36b of both tractors is the smallest, there is a possibility that tension may be generated due to a change in the paper width due to a change in humidity. Therefore, there is a problem that it is not possible to completely prevent the paper from getting over the hole and jamming the paper.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a continuous paper conveying mechanism capable of absorbing a force directed to a paper center line.

[0024]

As shown in FIG. 1, the present invention is a continuous machine having a tractor 3 for transporting the continuous paper 1 upstream of a photosensitive drum 4 disposed in a transport path for the continuous paper 1. In the paper transport mechanism, a transport roller 71 is provided between the photosensitive drum 4 and the tractor 3 to transport and drive the continuous paper at the same speed as the transport speed of the tractor 3.

Further, as shown in FIG. 2, a pair of tractors 3a, 3b 'slidably supported by the tractor drive shaft 34 and a guide shaft 35 parallel to the tractor drive shaft 34 are provided on both side edges of the continuous paper 1. In a continuous paper transporting mechanism that transports by engaging the feed holes 1a and 1b, the other tractor 3b 'is arranged with the one tractor 3a locked to the guide shaft 35 as a reference, and the other tractor 3a.
b'is a holding means 37 locked to the guide shaft 35 centered on a position aligned with the widthwise interval of the feed holes of the continuous paper 1.
Is configured to be swingably suspended in the width direction through a plurality of elastic members 373 and 374.

The mechanisms shown in FIGS. 1 and 2 are combined and configured.

[0027]

In FIG. 4, a conveyance roller 71 is provided between the tractor 3 and the photosensitive drum 4, and the paper conveyance speeds of the tractor 3 and the conveyance roller 71 are controlled to the same speed by the constant speed control unit 91. The tension in the direction of arrow C described above is absorbed by the conveyance roller 71, and the tension generated in the directions of arrows D and D ′ may remain due to the change of the paper width due to the change of humidity and the like. Like arrow type and swing type,
By using the means for relaxing the tension in the D'direction, it is possible to prevent the sheet from passing through the hole and the sheet jam.

Further, since the rotational linear velocity of the photosensitive drum 4 is controlled to be slightly higher than that of the conveying roller 71, the slack between the conveying roller 71 and the photosensitive drum 4 can be prevented. Further, as shown in FIG. 2, a pair of tractors 3a, 3b 'slidably supported by the tractor drive shaft 34 and the guide shaft 35 arranged in parallel are provided with feed holes 1a, 1a, 3b on both side edges of the continuous paper 1. 1b is engaged, and one tractor 3a is locked to the guide shaft 35 by the lock knob 36
The other tractor 3b 'is locked by using a, and the other tractor 3b' is swingably held by a holding means 37 around a position corresponding to the interval W in the paper width direction of the feed hole of the continuous paper 1.

The holding means has a holding plate 371 slidably locked to the guide shaft 35, and the holding plate 371 and the other tractor 3b 'are suspended via elastic members 373 and 374, and the humidity of the continuous paper 1 is increased. The distance between the two tractors is maintained by following a change in the distance W between the feed holes in the paper width direction due to a change or the like. As a result, the tension in the directions of arrows D and D'shown in FIG.
It is possible to prevent paper jams and paper jams.

By mounting the conveying roller 71, the constant velocity control section 91 and the holding means 37 together, the tension in the direction of arrow C acting on the feed hole shown in FIG. The synergistic effect of alleviating the tension in the D and D'directions can completely prevent the paper from passing through the hole and jamming the paper.

[0031]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a layout of a continuous paper transport mechanism of the present invention. In the figure, 71 is a conveying roller provided between the photosensitive drum 4 and the tractor 3, and the conveying roller 71 conveys the continuous paper 1 sent from the tractor 3 to a constant speed control unit.
The 91 drives the tractor 3 in the direction of the photosensitive drum 4 at the same speed as the tractor 3.

The carrying roller 71 is, for example, a scuff roller 7
Similarly, one of the pair of rollers is a driving roller and the other is a driven roller, and the continuous paper 1 is conveyed while both rollers are in close contact with each other.

By the way, in order to prevent the occurrence of the slack of the paper on the paper transport path, the control unit 9 is adjusted so that the transport speed of each of the scuff roller 7, the photosensitive drum 4, and the tractor 3 becomes higher toward the downstream side. . Therefore, by providing the carrying roller 71 having the same speed as the carrying speed of the tractor 3 between the tractor 3 and the photosensitive drum 4, the tension in the direction of arrow C remains on the continuous paper 1 downstream of the carrying roller 71 as in the conventional case. , Prevent paper slack.

Further, since the tractor 3 and the conveying roller 71 convey the continuous paper 1 at the same speed, the tractor 3 and the conveying roller 71
The tension in the direction of arrow C described with reference to FIG. Therefore, only the tension generated in the directions of the arrows D and D ′ remains, but the adjustment distance W ₂ of the expansion type described in FIG. 5 is adjusted, or the tension in the directions of the arrows D and D ′ is relaxed as in the swing type. By using the means, an unreasonable force does not act on the engagement between the feed hole and the pin, and it is possible to prevent the sheet from passing through the hole and the sheet jam.

FIG. 2 shows a mechanism diagram of a main part of the tractor of the present invention and a layout diagram of the photosensitive drums. In the figure, 3b 'is a tractor
Although it is a tractor paired with 3a, it differs from the tractor 3b shown in the conventional example only in that a lock knob is not provided.

Reference numeral 37 is a holding means, which is a tractor drive shaft 34.
And a holding plate 371 slidably supported in the axial direction by a guide shaft 35 parallel to the shaft 34, and a holding plate 371 integrally formed on the holding plate 371 and at an arbitrary position on the guide shaft 35. A lock knob 372 that locks the 371, and an elastic member (hereinafter, abbreviated as a spring) 37 that connects the holding plate 371 and the tractor 3b ′ to each other 37
It consists of 3 and 374.

The springs 373 and 374 are fixed to the holding plate 371, and have a function of suspending the tractor 3b ′ so as to be elastically swingable in the width direction of the continuous paper 1. This spring 373, 37
Reference numeral 4 denotes a coil spring provided coaxially with each of the tractor drive shaft 34 and the guide shaft 35, but is not limited to the coil spring, and a leaf spring or the like may be used. These springs may have a function of flexibly returning to the original position with a weak elasticity for a movement amount of only a few mm.

First, one tractor 3a is locked to the guide shaft 35, and the feed hole 1a of the continuous paper 1 is inserted into the pin row 32a of the tractor 3a.
To close the paper retainer shown in FIG. Next, the feed hole 1b of the continuous paper 1 is engaged with the pin row 32b of the other tractor 3b ', and the holding plate 371 corresponding to the position of the tractor 3b' aligned with the width W of the continuous paper 1 in the widthwise direction. Position locked to guide shaft 35 with lock knob 372. In this case, the spring 37
Operate the 3,374 so as not to apply excessive force.

Both tractors 3a thus positioned,
When the continuous paper 1 is conveyed and driven by the tractor drive shaft 34 on 3b ', even if the width W of the continuous paper 1 in the width direction changes due to an external factor, the distance between the pin rows 32a and 32b of both tractors is
The spring 373, with the feed hole interval W initially set as the center position,
Since the 374 follows the swinging motion, it is possible to prevent paper jams and jams.

In both the conventional expansion type and swing type shown in FIG. 5, both tractors are locked by the lock knob, so that there is a limit to the range in which the amount of change in the feed hole distance W can be followed. According to the holding means 37, the followable range can be widened by appropriate setting of the elastic force, so that an excellent function of conveying continuous paper can be exhibited.

Further, the transport roller 71 described with reference to FIG.
4 and the holding means 37 described in FIG. 2 are combined and provided side by side, the tension in the direction of arrow C shown in FIG. 4 is absorbed by the transport roller 71, and the tension in the directions of arrows D and D ′ is also continuous.
It is possible to obtain the synergistic effect of being relaxed by following the change in the feed hole distance W in the width direction.

[0042]

As described above, according to the continuous paper transporting mechanism of the present invention, it is possible to reduce or equalize the unnecessary force received by the continuous paper during the transportation of the paper, and to stabilize the paper transportation. It greatly contributes to the improvement.

[Brief description of drawings]

FIG. 1 is a layout drawing of a continuous paper transport mechanism of the present invention.

FIG. 2 is a schematic diagram of a main part of a tractor of the present invention and a layout diagram of photosensitive drums.

FIG. 3 is a layout diagram showing an example of a conventional electrophotographic continuous paper printing apparatus.

FIG. 4 is a schematic front view of a conventional tractor and a layout diagram of a photosensitive drum and continuous paper.

FIG. 5 is an engagement operation diagram of a pin row and a feed hole of a conventional example.

[Explanation of symbols] 1 continuous paper 1a, 1b feed hole 3 tractors 3a, 3b 'pair of tractors 4 photosensitive drum 34 tractor drive shaft 35 guide shaft 37 holding means 373,374 elastic member (spring)

Claims (3)

[Claims] 1. A continuous paper transport mechanism including a tractor for transporting the continuous paper upstream of a photosensitive drum arranged in a continuous paper transport path, wherein the tractor is provided between the photosensitive drum and the tractor. 2. A continuous paper transport mechanism comprising a transport roller for transporting and driving the continuous paper at the same transport speed as that of 1. 2. A continuous paper transport mechanism for transporting a pair of tractors slidably supported by a tractor drive shaft and a guide shaft parallel to the shaft by engaging feed holes on both side edges of the continuous paper for transport. The other tractor is arranged on the basis of the one tractor locked to the guide shaft, and the other tractor is locked to the guide shaft around a position aligned with the widthwise interval of the continuous paper feed holes. The continuous paper transport mechanism, which is suspended by the holding means so as to be swingable in the width direction via an elastic member. 3. A continuous paper transport mechanism comprising a combination of claim 1 and claim 2.