JPH0361260A - Decurl mechanism and recording device using decurl mechanism - Google Patents

Abstract

PURPOSE:To minimize migration torque at the time of shifting into the recording stand-by state so as to reduce the load of the driving source of a motor or the like by providing a shifting means with migration torque according to the roll diameter of sheet material. CONSTITUTION:At the time of conveying a sheet material 5, a shifting means stops in the balanced state between tension applied to the sheet material 5 and energizing force by an energizing means 32. Accordingly, when the tension is large, the influence of the energizing force on the shifting means 26 is small, and the acting quantity of the shifting means 26 becomes small and therefore the curvature of the sheet material 5 becomes small. In this case, the energizing means 32 provides the shifting means 26 with the maximum migration torque when the roll diameter is relatively large for instance, and the migration torque is made smaller when the roll diameter is small or as the shift into the recording stand by state is made. The driving load of the shifting means 26 can be thus lightened.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a decurling mechanism for correcting curling of a sheet material wound into a roll, and a recording apparatus having the decurling mechanism.

<Prior Art> Today, office equipment such as facsimile machines and printers are widely used, and the recording systems of these devices generally use a roll sheet in which a long recording sheet is wound around a core.

Since this sheet material is wound into a roll, curls (hereinafter referred to as decals) are likely to occur, and curled sheet materials are likely to jam during transportation. For this reason, many of the recording devices that use the roll sheet to remove or reduce the curl use Decal 8! A structure has been established.

An example of the decurling mechanism is one constructed as shown in FIG. 11, for example.

This is configured such that a main body 51 and a lid 52 can be opened and closed by a pin 53, a roll holder 54, a platen roller 55, and a cutter 56 are provided in one main body 51, and the other lid 52 is provided with a roll holder 54, a platen roller 55 and a cutter 56.
2 is provided with a decurling shaft 57 and a recording head 58 that constitute a decurling mechanism.

To explain the operation of the device, a sheet roll 59a in which a sheet material 59 is rolled is loaded into a roll boulder 54, and the sheet material 5 is rolled by rotation of the platen roller 55.
9 via the decal shaft 57,
The image is formed in five days by the recording head, cut by a cutter 56, and discharged from the apparatus.

In the above-mentioned apparatus, curling is reduced by conveying the sheet material 59 while being bent in the opposite direction to curling by the decurling shaft 57.

In this case, as shown in FIG. 12, it is known that the larger the center angle α of the sheet material 59 around the decal shaft 57, the greater the curl correction effect.

<Problem that the invention sought to solve> Decal 8 in Figure 11 above! In the structure, sheet material 5
9 is used, the diameter of the sheet roll 59a becomes smaller, and the center angle α of winding the sheet material 59 with respect to the decal shaft 57 gradually becomes smaller from α1 to α2.

Therefore, the curl removal effect of the sheet material 59 gradually decreases, and even though the curl is tighter as the diameter of the sheet roll 59a is smaller, sufficient curl removal is often not performed.

In particular, in recent years, as the core of the sheet roll 59a has been made smaller in order to downsize the apparatus, the curl of the sheet material 59 has become tighter, and there is a need for a decurling mechanism with a stronger curl removal effect.

The present invention solves the above problems of the prior art, removes curls according to the amount of bending of the sheet material, and applies a moving torque to the moving means according to the roll diameter of the sheet material. The present invention provides a decurling mechanism that reduces the driving load on a device, and a recording apparatus having the decurling mechanism.

<Means for solving the problem> i! ! ! A typical means of the present invention for solving the problem includes a conveyance means for conveying a sheet material, a guide member for guiding the conveyance of the sheet material, and a bending guide for the conveyed sheet material. Decal parts for
A decurling mechanism is configured by providing a moving means for moving at least one of the guide member and the decurling member, and a biasing means for applying a moving torque to the moving means according to the roll diameter of the sheet material. It is characterized by this.

Effect> In the above means, when conveying the sheet material, the moving means stops in a state where the tension applied to the sheet material and the urging force of the urging means are balanced. Therefore, when the tension is large, the influence of the biasing force on the moving means is small, and since the amount of movement of the moving means is small, the bending of the sheet material is reduced. On the other hand, when the tension 5 is small, the amount of movement of the moving means increases, contrary to the above, and the amount of bending of the sheet material increases. As a result, curl correction is performed according to the curl strength.

Further, since the moving means is biased by the urging means, no load is applied to the conveying means to operate the moving means.

Furthermore, by providing the guide member and the decal member separately in the main body of the device and the lid, the guide member and the decal member are separated by a large distance when the lid is opened, making it easier to load the sheet material. Become.

Furthermore, by making the moving force of the moving means larger than the urging force of the urging means against the moving means, it is possible to move the moving means in a direction in which the sheet material does not bend against the urging of the urging means. It is possible to prevent the sheet material from being unnecessarily decurled in the conveyance standby state.

Further, the biasing means applies a maximum moving torque to the moving means when the roll diameter is relatively large, and decreases the moving torque when the roll has a small diameter or as the state shifts to a recording standby state, thereby reducing the driving load on the moving means. It can be reduced.

Further, by increasing the self-holding force of the drive source of the moving means to a certain extent, the relationship between the guide member and the decal member can be maintained appropriately.

Also, the decal af! to configure the recording device,
The conveying means and the moving means are operated by the same driving source, and the moving means returns to the initial position when the driving source is driven to reversely feed the sheet material from the cutter to the recording means. In the recording standby state, the moving means is always located at the initial position.

Further, by setting the output of the %ilK movable power source to be larger when the sheet material is being transported in the opposite direction to the recording direction than when the sheet material is being transported in the recording direction, it is possible to stably transport the sheet material. It is what it is.

<Embodiment> Next, an embodiment in which the above means is applied to a facsimile machine will be described.

Figure 1 is a perspective explanatory diagram of the recording system of a facsimile machine;
The figure is an explanatory cross-sectional view of the entire facsimile machine.

As shown in FIG. 2, this facsimile apparatus is comprised of a recording system B having a decurling mechanism A and an original reading system C.

First, the overall configuration will be briefly described with reference to FIG. 2. Recording system B has a device main body 1 and a lid 2 that can be opened and closed by a shaft 3. The lid 2 is connected to the main body 1 by a click mechanism (not shown). It is constructed so that it can be locked to. Further, a roll holder 4 is provided at a predetermined position on the back side of the main body of the recording system, and a roll 5a of a heat-sensitive sheet material 5 wound into a roll is loaded into the holder 4. This sheet material 5 is conveyed by the rotation of a platen roller 6a constituting a conveyance means, and at this time, when passing through the decurling mechanism A, the sheet material 5 is bent in the opposite direction to the curl direction, thereby correcting the curl.

A predetermined image is formed on the sheet material 5 whose curl has been corrected in a recording means 6, and the sheet material 5 after recording is cut by a force/interchanger 7 and discharged to a discharge stacker 9 by a discharge roller 8. has been done.

The document reading system C places a plurality of documents 11 on the document mounting table IO formed on the top surface of the lid body 2, and when a reading operation is performed, the document reading system C reads several documents from the bottom among the plurality of documents 11 that have been placed. The document 11 is conveyed by the pre-all conveyance roller 12a and the pressure contact member 12b in pressure contact therewith, and then transferred to the separation roller 13.
A and a pressure contact member 13b that presses against the pressure contact member 13b are configured to separate and supply one sheet at a time. Further, the separated original 11 is transported by transport roller pairs 14a, 14b and 15a, 15.
While being transported by the light source 16, the reflected light reaches a photoelectric conversion element 19 such as a CCD via a mirror 17 and a lens 18, where it is converted into an electrical signal. is transmitted to recording system B of
In the case of a facsimile remote, the information is configured to be transmitted to the recording system of another machine.

Next, the configuration of each part of the recording system B having the decurling mechanism A in the fusing device will be explained in detail.

The roll holder 4 is formed with an open top, and is arranged at the back side of the recording system main body 1. The roll holder 4 is loaded with a sheet roll 5a, and the outer circumferential surface of the roll 5a and the inner surface of the holder 4 come into contact with each other, creating frictional resistance. That is, when the sheet material 5 is drawn out, when the roll 5a has a large diameter and is heavy, a large frictional resistance is generated, and as the sheet material 5 is drawn out and the weight of the roll 5a decreases, the frictional resistance also decreases. This frictional resistance has the effect of imparting tensile strength to the sheet material 5 when the sheet material 5 is drawn out, and the strength of the sheet material 5 that is drawn out is proportional to the magnitude of the frictional resistance.
The tensile strength applied to this will also change.

Recording means 6 for recording a predetermined image on the sheet material 5
The configuration consists of a platen roller 6a and a recording head 6b. The platen roller 6a is a roller-shaped member made of a material with a high friction coefficient such as hard rubber, which is rotatably attached to the main body 1, and is connected to a motor 2 serving as a driving source.
It is configured to be driven at 0. That is, as shown in FIG. 1, the rotational force of the motor 20 is transmitted from a gear 21a fixed to the motor shaft via an intermediate gear 21b to a gear 21c fixed to the roll shaft of the platen roller 6a, causing the platen roller 6a to rotate. do. The sheet material 5 is conveyed by the rotation of the platen roller 6a, and the platen roller 6a also serves as a means for conveying the sheet material 5.

The recording head 6b forms an image on the sheet material 5 by heating the sheet material 5 according to an image signal, and is configured to press the platen roller 6a through the sheet material 5. Specifically, the lid body 2 is
The platen roller 6a is rotatably attached to the platen roller 6a by a compression spring 6d when the lid body 2 is closed. Therefore, when the platen roller 6a rotates with the sheet material 5 inserted between the platen roller 6a and the recording head 6b, the sheet material 5 is conveyed.

The recording head 6b in this embodiment uses a so-called line-type thermal head in which a large number of heating elements 6b that generate heat when energized are arranged in the width direction of the sheet material 5 on the surface that contacts the sheet material 5. The sheet material 5 is selectively heated by energizing the heating element 6b in accordance with an image signal, and the heat-sensitive sheet material 5 is colored to perform recording.

Next, the cutter 7 has a fixed blade 7a and a driving blade 7b in this embodiment.
A rotary cutter consisting of is used. Specifically, the fixed blade 7a is fixed to the main body 1, and the driving blade 7b is attached to be rotatable about the shaft 7C, and when the driving blade 7b is rotated by the driving means, it rubs against the fixed blade 7a. This is for cutting the sheet material 5.

The drive blade 7b may be configured to be driven by the motor 20 that drives the platen roller 6a, or may be driven by another independent motor.

The sheet material 5 cut by the cutter 7 is discharged to a stacker 9 by a discharge roller 8 driven by a drive means (not shown), but since the sheet material 5 used for recording is wound around a core 5b, The sheet is curled when it is pulled out from the sheet roll 5a.

The curl becomes blue depending on the diameter of the roll 5a.

For example, when the roll diameter is large, the curl height h shown in FIG. 4 (al) is small, and as the roll diameter becomes smaller, the curl height h becomes larger.

Furthermore, it curls up as shown in FIG. 4(b).

In the apparatus of this embodiment, the curl is corrected when the sheet material 5 passes through the decurling mechanism A.

That is, the position of the guide shaft 23 serving as a guide member is configured to be movable with respect to the decal shaft 22 serving as a decal member, and the sheet material 5 is attached to both shirts) 22.23.
The curl is corrected by being bent in the opposite direction to the curl direction when being guided.

The guide shaft 23 is biased against the sheet material 5 by a biasing means to be described later, and is loaded with a large diameter roll 5a as shown in FIG. 5(a), and with a small diameter roll 5a as shown in FIG. 6(a). The decal effect is now different depending on when it is loaded.

Here, the structure of the decurling mechanism A will be specifically explained.

As shown in FIG. 1, the decal shaft 22 is rotatably attached to a pair of attachment members 24 fixed to the lid body 2. This decal shaft 22 is composed of a cylindrical metal shaft with a diameter of 4 mm, for example. The mounting member 2
4 stands up on the back surface of the lid body 2, and the interval therebetween is larger than the width of the sheet material 5, and smaller than the interval between arms supporting both ends of a guide shaft 23, which will be described later.

The decal shaft 22 is shown in FIG. 5(a) and FIG. 6(
As shown in a), when the lid body 2 is closed, its position with respect to the main body l is always constant, and the position at this time is on the upstream side in the conveyance direction of the sheet material 5 with respect to the platen roller 6a, and It is arranged at a position where the angle at which the material 5 is introduced into the platen roller 6a does not become too large.

Further, a guide 34 is provided on the main body 1 facing the decal shaft 22 for guiding the sheet material 5 pulled out from the roll 5a to the platen roller 6a. One end of this guide 34 extends to the vicinity of the platen roller 6a, and the other end is configured to be integrated with the roll holder 4.

On the other hand, the guide shaft 23 is constituted by a metal shaft having a diameter of about 4 m+++, for example.

Further, the guide shaft 23 is configured to be movable relative to the decal shaft 22 by a moving means. As shown in FIG. 1, the structure of this moving means is that two arms 26 are fixed to a shaft 25 attached to the main body 1.
A guide shaft 23 is rotatably attached to the tips of both arms 26, and when the shaft 25 rotates, the arms 26 rotate together, thereby making the guide shaft 23 movable with respect to the decal shaft 22. There is.

The shaft 25 is rotatably attached to the main body l via a bearing 27, and one end of the shaft is a biasing means for applying a moving torque to the moving means according to the roll diameter of the sheet material. Clutch gear 28. Spring Franch29. Crank 30. and a tension spring 32 are attached, so that rotational force in only one direction is transmitted to the shaft 25.

As shown in FIG. 3, the crank 30 has a cylindrical portion 30a and a crank plate 30b, and the cylindrical portion 30a is connected to the shaft 25.
It is fitted integrally with the body and rotates in the same direction. Further, a projection 30c is provided at one end of the outer surface of the crank plate 30b.
A tension spring 32 is installed between the protrusion 31 and the protrusion 31 protruding from the main body l. The above tension spring 32
Rotational torque in the direction of arrow a is always generated in the crank 30 due to the elastic force.

Further, the clutch gear 28 includes a cylindrical portion 28a and a gear portion 28.
b, and the inner diameter of the hole through which the shaft 25 is inserted is the shaft 25.
It is formed to be slightly larger than the outer diameter of the shaft 25, and is rotatably attached to the shaft 25.

The spring clutch 29 is formed by winding a spring steel wire, a spring steel strip, a plastic wire, etc. into a coil shape, and is wound around the outer periphery of the cylindrical portion of the clutch gear 28 and the crank 30, and one end thereof is connected to the crank plate 30b. It is locked in.

The spring clutch 29 transmits the rotational force of the clutch gear 28 to the crank 30 in only one direction, and not in the other direction. That is, when the clutch gear 28 rotates in the direction of arrow a in FIG. 1, the spring clutch 29 is loosened and becomes free, and no rotational force is transmitted to the crank 30. On the other hand, the clutch gear 28 is indicated by the arrow -a opposite to the above.
(hereinafter, the minus sign indicates the opposite direction of the arrow), the honey clutch 29 rotates in the direction of the clutch gear 28.
Then, the cylindrical portion 30a of the crank 30 is tightened to be in a locked state, and the rotational force is transmitted to the crank 30, and the rotational force that moves the guide shaft 22 in the direction indicated by the arrow is transmitted.

The drive source for rotating the clutch gear 28 is the same as the drive source for rotating the platen roller 6a,
It is driven by a motor 20. That is, as shown in FIG. 1, the driving force of the motor 20 is transmitted through the gears 21a to
21c, the gear 21c attached to the platen roller shaft meshes with a gear portion of a clutch gear 28 via an intermediate gear 21d.

Therefore, as shown in FIG. 1, when the motor 20 rotates forward in the direction of arrow C, the platen roller 6a rotates in the direction of arrow d, and the clutch gear 28 rotates in the direction of arrow a. That is,
When the platen roller 6a rotates in the direction of drawing out the sheet material 5 in the direction of arrow C, the spring clutch 29 is in a free state.

Further, when the motor 20 rotates in the opposite direction of the arrow -C, the platen roller 6a rotates in the direction of feeding the sheet material 5 in the reverse direction, and at this time, the clutch gear 28 rotates in the direction of the arrow -a, and the spring clutch 29 rotates in the direction of the arrow -a. is in a locked state and transmits the rotational force that rotates the guide shaft 23 in the direction indicated by the arrow in FIG.

Due to the tensile force of the tension spring 32, the shaft 25 is always urged in the direction of arrow a in FIG. 1 (the direction in which the decurling effect by the guide shaft 23 becomes greater).

Further, a stopper 33 is provided at a predetermined position on the main body 1 within the rotation range of the arm 26.

This stopper 33 comes into contact with the arm 26 when it rotates in the direction of arrow -b in FIG. This is what you set.

Next, the operation when recording using the recording system B having the decurling mechanism A configured as described above is shown in the case where the roll diameter is large as shown in FIG. 5(a) and the case shown in FIG. 6(a). The following will focus on the curl straightening effect when the roll diameter is small.

First, the lid body 2 is opened, the sheet roll 5a is loaded into the roll holder 4, and the leading edge of the sheet is pulled out to the platen roller 6a and then sent. At this time, as shown in FIGS. 1 and 2, the decal shaft 22 is attached to the lid 2 and the guide shaft 23 is attached to the main body 1, so when the lid 2 is opened, both shafts 22 and 23 are attached. The sheet materials 5 can be easily set at large distances.

Next, when the recording start signal is input with the lid 2 closed,
The motor 20 rotates normally, the platen roller 6a rotates in the direction of arrow d, and the sheet material 5 is conveyed in the direction of arrow C. In synchronization with this conveyance, the heating element 6b+ of the recording head 6b selectively generates heat to perform predetermined recording on the sheet material 5. Then, when the sheet material 5 is conveyed, the decurling mechanism A operates to correct the curl of the sheet material 5.

That is, the forward rotation driving force of the motor 20 is also transmitted to the clutch gear 28, but as described above, the spring clutch 29 is in a free state and the clutch gear 28 is rotating idly with respect to the crank 30.

On the other hand, since a biasing force in the direction of arrow a is applied to the shaft 25 by the elastic force of the tension spring 32 as shown in FIG.
The arm 26 rotates in the direction of arrow -b and the guide shaft 2
3 moves and stops at a position balanced with the tension of the sheet material 5.

As a result, the conveyance path of the sheet material 5 is wound around the guide shaft 23 from the sheet roll 5a in the curling direction.
Next, the decal is bent at the decal shaft 22 and attached to the shaft 22 in a direction opposite to the curl.

This winding around the decal shaft 22 corrects the curl of the sheet material 5.

Here, the tension applied to the conveyed sheet material 5 is caused by the contact friction between the roll holder 4 and the roll 5a loaded on this holder 4.

That is, as shown in FIG. 5(a), if the weight of the roll 5a is G and the tension acting on the sheet material 5 is F, then the friction force generated on the sheet material 5 due to the weight G1 is Tension F1 and rotational force of arm 26 (
The arm 26 stops at a position where the rotational torque of the crank 30 due to the tensile force of the tension spring 32 is balanced.

As shown in FIG. 5(a), when the roll diameter is large, for example, when a 100 m roll of a 65 μm thick thermal sheet is used around a 1 inch core, the tension Fl against the sheet material 5 and the arm 26 When the rotational force is balanced, the wrapping angle at which the sheet material 5 is wound around the decal shaft 22 is θ1, and then the sheet material 5 is guided to the platen roller 6a. If the wrapping angle θ with respect to the decal shaft 22 is larger than necessary, there is a risk that reverse curling will occur in the opposite direction, so the wrapping angle θ should be changed to an appropriate value depending on the diameter of the sheet roll 5a. The elastic force of the tension spring 32 may be set as follows. Experimentally, in the case of the sheet roll 5a in this example, the above-mentioned wrapping angle θ was determined as shown in Fig. 5).
1 is 120° ~ 90° 1 winding center angle α is 60' ~ 90°
It is desirable to set the elastic force of the tension spring 32 so that .

On the other hand, as shown in FIG. 6(a), when the diameter of the roll 5a becomes smaller and, for example, about 20 minutes remain, the roll weight G2
(ci<cu, the tension F2 acting on the sheet material 5 also becomes smaller (P!<Fl), so the arm 26 is further moved by the arrow - than when the roll diameter is large.
Rotate in direction b. If the rotational force of the arm 26 and the tension F2 are balanced, the arm 26 will stop at that position, but if the amount of rotation of the arm 26 is greater, it will stop at the position where it abuts the stopper 36. At this time, the wrapping angle at which the sheet material 5 is wrapped around the decal shaft 22 is θ2, and when the roll diameter is large, the wrapping angle θ
becomes smaller than 1. As mentioned above, the wrapping angle θ8 is determined by the elastic force of the tension spring 32, but experimentally, in the case of the sheet roll 5b, the wrapping angle θ2 is determined as shown in FIG. 6(b).
is 06” to 30’, and the winding center angle α2 is 150” to 18
It is desirable to set the guide shaft 23 so that it is 0''.In this case, the position of the guide shaft 23 is
The position is approximately directly above or closer to the platen roller 6a side.

Therefore, when the diameter of the roll 5a is large, the amount of wrapping of the sheet material around the decal shaft 22 is small, and as the roll diameter becomes smaller and the curl becomes stronger, the amount of wrapping increases. As the amount of wrapping increases, the sheet material 5 is bent in the direction opposite to the curl, so that the curl correction effect increases. That is, the curl correction effect increases as the roll diameter, which causes stronger curling, becomes smaller.

Here, the results of an experiment in which sheet materials 5 of various roll diameters were conveyed by the decurling mechanism A and curls were corrected will be shown.

The sheet material 5 used in this experiment has a width of 210R111 (A
4 sizes) and 100 m long thermal recording paper to 1 inch (2
5.4 mm) sheet roll 5a wound around a winding core 5b
was used. In this case, when the sheet is not used, the roll 5a
The diameter was 96 mm. Also, the rotational force of the arm 26 is 1k.
The tension spring 32 was set so that the decal shaft 22 had a diameter of 4 mm, and the radius of movement of the guide shaft 23 was 13 mm. Furthermore, the range of the wrapping angle θ where the sheet material 5 wraps around the decal shaft 22 is set to 13.
Constructed so that the angle is 0° to 30°, and the sheet material 5 is 297
I sent 111Il (A4 size length) III and looked at the results.

The experimental results were as shown in FIG. In Figure 7, the white triangles are the curl shapes shown in Figure 4 (a) without curl correction, and the black triangles are the curl shapes shown in Figure 4 (a) without curl correction. (b), and the white circle is the one that has been curled by the decal mechanism A, and the curled state is shown in Figure 4 (
a).

As is clear from this result, the larger the diameter of the roll 5a, the smaller the curl height h of the sheet material 5, and the smaller the roll diameter, the smaller the curl height h.
The value of increases. When the roll diameter becomes less than about 40 m5+, curling occurs.

On the other hand, the sheet material 5 decurled by the decurling mechanism of the above-mentioned example had almost no curling, and the measured curl height h showed a substantially constant value.

In this way, the decurling mechanism A changes the decurling effect depending on the strength of the curl by balancing the tension acting on the sheet material 5 and the rotational force of the arm 26, and corrects the curl appropriately.

Further, the arm 26 is biased by a tension spring 32, and the rotational force of the motor 20 in the C direction is transmitted to the platen roller 6a but not to the arm 26. Therefore, since no load is applied to the motor 20 during recording to move the arm 26, the conveyance accuracy is increased and high-quality recording can be performed.

Next, the relationship between the rotational angle θ and the rotational torque T of the shaft 25 for maintaining the guide shaft 23 at an appropriate position according to the diameter of the sheet roll 5a will be explained with reference to FIG.

In FIG. 8, first, when the sheet roll 5a is a small roll (for example, when there is 1 m remaining), the motor 20 rotates in the C direction, the shaft 25 is driven to rotate in the a direction, and the guide shaft 23 is rotated in the direction a. It rotates in the -b direction about the axis 25 of , and rotates to the position 23a. At this time, the wrapping center angle α2 of the sheet material 5 with respect to the decal shaft 22 is 1
It is 50°. In order to stabilize the guide shaft 23 in this position, the shaft 25 must be given -b forward rotational torque T=20
0 gcm was required.

In addition, in the case of a large diameter roll (for example, when it is unused and 100 m long), the motor 20 similarly rotates in the C direction, so that the shaft 25 is driven to rotate in the a direction, and the guide shaft 23
rotates in the -b forward direction about the axis 25 in the figure and rotates to the position 23b. At this time, the center angle α1 of wrapping the sheet material 5 around the decal shaft 22 is 90''.At this time, the tension of the sheet material 5 increases compared to when it is rolled with a small diameter, so it is pulled back by θ-45° in the direction indicated by the arrow. .

In order to stabilize the guide shaft 23 in this position,
A rotational torque T=400 gcm was required for the shaft 25 in the -b direction.

In addition, in the recording standby state, as the motor 2o rotates in the direction C, the shaft 25 rotates further in the direction of arrow -a than in the case of a large diameter roll, and the guide shaft 23 rotates in the direction of arrow A. and rotates from the position 23a to a position 23c at θ=135°.

It should be noted that the rotational torque T, the winding center angle α1 with respect to the decal shaft 22, The relationship between α2 and curl is the sheet material 5
The rotational torque T may be set as appropriate depending on the type (core diameter, paper thickness, etc.), or the rotational torque T may be ':;'+time-constant. Moreover, the value of T may be maximum not only for a large diameter roll but also for any roll diameter.

According to the above embodiment, based on the position 23a of the guide shaft 23 when using the small diameter sheet roll 5a,
When the rotation angle θ at which the guide shaft 23 rotates in the direction indicated by the arrow due to the rotation of the shaft 25 is from 0° to 45°, the rotational torque T increases as the rotation angle θ increases.

Then, when θ=45@ or more, the rotational torque T decreases and reaches a minimum in the recording standby state.

Next, FIG. 9(a) shows a configuration for obtaining the characteristics of the rotational angle θ and rotational torque T of the guide shaft 23.
b) Explain with reference to (C). In the figure, l is the length of the tension spring 32, P is the elastic force of the tension spring 32, and r is the elastic force P.
2 shows the perpendicular distance between the line of action and the axis 25, respectively.

FIG. 9(a) shows the case when a small diameter roll is used, FIG. 9(middle) shows the case when a large diameter roll is used, and FIG. 9(C) shows the recording standby state.

The tension spring 32 moves the shaft 25 through the crank 30 in the direction of arrow -a.
The torque T for rotating in the direction is given by -Pr.

When a large diameter roll is used instead of the small diameter roll shown in FIG. 9(a), the crank 30 and shaft 25 are pushed back in the direction of arrow -a by the tension of the sheet material 5, and the guide shaft 23 rotates in the direction of the arrow. . At this time, the tension spring 32
By stretching, the elastic force P increases. Also, the vertical pressure between the line of action of the elastic force P and the shaft 25 is 1liilIl
Since r also increases, rotational torque T also increases. and,
As shown in FIG. 9 α)), the rotational torque T is at its maximum when the longitudinal center line of the crank plate 30a and the line of action of the elastic force P are perpendicular to each other.

During recording standby, the crank 30 and shaft 25 rotate further in the direction of arrow -a than when using a large-diameter roll, and the guide shaft 23 rotates in the direction indicated by the arrow. At this time, as shown in FIG. 9(C), the tension spring 32 is further stretched, so the elastic force P increases.

However, since the vertical distance r between the line of action of the elastic force P and the shaft 25 is significantly reduced, the rotational torque T is reduced as a whole.

FIG. 10 shows the above relationship in a graph.

In FIG. 10, a straight line indicated by a dotted line indicates the case where a rotational torque T is applied to the shaft 25 by a coil spring or the like. In this case, during recording standby, a torque of 800 gcm+ is required, which is approximately twice the torque T required for large-diameter rolls. Therefore, it is necessary to increase the output of the motor 20 that rotates the shaft 25, and there is a possibility that problems such as load fluctuations on the platen roller 6a may occur.

In this embodiment, the value of the rotational torque T of the shaft 25 with respect to the rotational angle θ of the guide shaft 23 is maximized at a relatively large arbitrary roll diameter, so that the guide shaft 23 is connected to the tension spring 32 during recording standby. The load on the motor 20 when rotating in the direction indicated by the arrow against the force P can be reduced, and the entire device can be downsized.

Note that the values of the rotational angle θ of the guide shaft 23 and the rotational torque T of the shaft 25 are not limited to those in the above embodiment, and may vary depending on the spring constant of the tension spring 32, the shape of the crank 30, and the protrusion 30.
b It is determined by appropriately selecting the position of the skin protrusion 31, etc.

Further, it is also possible to set the value of the rotational torque T to be larger when the diameter of the sheet roll 5a is small than when it is large.

Further, it is also possible to keep the rotational torque T constant using a constant torque mechanism such as a slip clutch or a negator spring, regardless of the roll diameter (that is, regardless of the position of the guide shaft 23).

After recording an image on the sheet material 5 whose curls have been corrected as described above, the cutter 7 is used to force and punch the image, and the FJ1 output roller 8
Discharge with.

On the other hand, the tip of the sheet material 5 in the device is cut into a cutter 7.
It is sent backward by a distance W1j2 from the position to the recording means 6. This is to avoid creating a blank area at the leading edge of the sheet during the next recording. Therefore, when the motor 20 is driven in the reverse direction by a predetermined amount, the driving force is transmitted not only to the platen roller 6a but also to the crank 30 as the spring clutch 29 becomes locked as described above, and the force rotates the arm 26 in the direction indicated by the arrow. acts.

At this time, as shown in FIG. 1, a tensile force is applied to the arm 26 by a tension spring 32 in a direction that prevents the rotation. For this reason, the driving force of the motor 20 in this embodiment is set to be larger than the arm rotation force due to the tension force of the tension spring 32 when driving in reverse as described above.

Therefore, when the motor 20 is driven in reverse to reversely feed the sheet material 5 as described above, the driving force causes the arm 26 to
is rotated in the direction indicated by the arrow, separated from the sheet material 5, and returned to the initial position shown by the two-dot chain line in FIG. Note that the initial position here refers to a position where the guide shaft 23 does not block the opening of the roll holder 4, and where the guide shaft 23 does not interfere with the decal shaft 22 when opening the lid body 2. . In this state, the guide shaft 23
is separated from the sheet material 5, the sheet material 5 will not be curled in the opposite direction even if the recording standby state continues for a long time.

Incidentally, in order to reversely feed the sheet material 5 by a distance l, the motor 2
The rotation angle M (return angle α) of the arm 26 when the arm 26 is driven in the reverse direction is set to the angle at which the arm 26 rotates from the position where it contacts the stopper 36 to the initial position as shown in FIG. 5(a). are doing.

That is, the motor 2 when rewinding the sheet material 5 by the length l
The distance l between the platen roller 6a and the cutter 7, the distance l between the platen roller 6a and the shaft 25, and the rotation amount of the motor 20 when rotating the arm 26 by the angle α in the direction indicated by the arrow are the same. The rotation ratio, the position of the stopper 36, etc. are set.

Next, the motor driving force required to operate each member will be explained when the motor 20 is driven in forward rotation and when it is driven in reverse.

If the motor output when driving the motor 20 in normal rotation (when conveying the sheet material 5 in the recording direction) is Pl, in this case, since the spring clamp/unch 29 is in a free state, the output P+ is the output from the platen roller. The driving force required to rotate 6a is sufficient.

On the other hand, if the motor output when driving the motor 20 in the reverse direction (when conveying the sheet material 5 in the rewinding direction) is set to P2, the spring clutch 29 is in a locked state in this case, so the output Pt is The driving force necessary to rotate the roller 6a and the driving force necessary to rotate the arm 26 against the tension spring 32 are required, and the driving force is larger than that in the case of forward rotation (P+<Pg )Is required.

Therefore, if the rated output of the motor 20 is set to P2, the surplus output (p, -p
+) may cause vibration, which may cause uneven feeding, noise, etc.

Therefore, in this embodiment, the output when driving the motor 20 in the normal rotation is set to P1, and when driving the motor 20 in the reverse rotation, the output is set to P2, which is larger than that when driving the motor 20 in the normal rotation. This can be easily accomplished by a known method such as increasing the driving current of the motor 20 during reverse rotation compared to normal rotation, or lowering the rotation speed.

As mentioned above, even if the drive current is increased or the rotational speed is set to a low value during reverse drive, the amount of rewinding (for example, about 20 nm) with respect to the transport distance of the sheet material 5 during recording (for example, 210 m5 for A4 size) Since this is sufficiently small, the influence of the temperature rise of the motor 20 during reverse drive or the delay in the reverse feeding time of the sheet material 5 is extremely small.

Also, an arm 2G driven by the motor 20
It is preferable to set the gear ratio and the like so that the rotational speed of the platen roller 6a is the same as or slightly faster than the rotational peripheral speed of the platen roller 6a (the conveyance speed of the sheet material 5). That is, by configuring as described above, the guide shaft 23 quickly retreats to the initial position when the sheet material 5 is fed back.

Incidentally, the motor 20 moves the sheet material 5 to a predetermined "Ji N
After returning to O, it comes to a halt state, but at this time the arm 26
is in a tensioned state by the tension spring 32.

As shown in FIG. 1, this tensile force is caused by an attempt to rotate the crank 30 in the direction of arrow a, which causes the spring clutch 30 to
becomes a locked state and becomes a force that urges the clutch gear 28 in the direction of arrow a, which acts as a rotational torque that rotates the motor 20 via the gears 21a to 21d.

For example, when the rotational torque for rotating the crank 30 in the direction of arrow a is T, (for example, about 1 kgcm), and the rotational speed ratio of the motor 20 and the clutch gear 28 is set to 10:1, the rotational force causes the motor 20 to rotate. The rotational torque Tt transmitted to is T+/10 (0.1kgcI11)
becomes.

Therefore, in this embodiment, in order to prevent the arm 26 from rotating when the motor 20 is stopped, the self-holding torque of the motor 20 (when torque is applied from the outside to the rotor made of permanent magnets, the magnetic force The torque at which the rotor attempts to come to a standstill) is greater than the rotation torque Tz transmitted to the motor 20 (for example, 0.2 kgcm).
It is set.

As a result, in the recording apparatus of this embodiment, in the recording standby state, the arm 26 is held at the initial position indicated by the two-dot chain line in FIGS. 5(a) and 6(a).

Therefore, when opening the lid 2, such as when replacing the roll 5a, the guide shaft 23 does not interfere with the decal shaft 22, and the lid 2 can be opened smoothly.

Since the device of this embodiment is configured as described above, it is possible to correct the curl according to the strength of the curl, and the load applied to the motor 20 during recording is only the load for rotating the platen roller 6a. Therefore, sheet conveyance is performed accurately, and furthermore, the roll 5a can be easily replaced.

<Other Embodiments> In the embodiments described above, an example was shown in which the guide shaft 23 was movable with respect to the decal shaft 22, but it is also possible to configure the decal shaft 22 to be movable with respect to the guide shaft 23. In this case as well, the moving means of the decal shaft 22 is provided with a Ji
It is possible to apply force. Furthermore, both the decal shaft 22 and the guide shaft 23 may be configured to be movable.

Further, in the above embodiment, the guide shaft 23 is attached to the arm 26 and moved by rotating the arm 26, but the moving means need not be limited to this. Alternatively, the decal shaft 22 may be configured to move in parallel along a rank or rail, or may be moved by being pushed up with a cam or the like.

Further, the cylindrical decal shaft 22. Instead of the guide shaft 23, a plate-like member such as a sheet metal having a curved surface having the same radius of curvature as that of each shaft can also be used.

Further, as a device for selectively transmitting the driving force of the motor to the decal shaft 22 or the guide shaft 23,
Although the spring clutch 30 is used in the embodiment, the present invention is not limited to this, and a roller type needle clutch or the like may be used.

Further, in the embodiment described above, the motor 20 that drives the platen roller 6a is used as a drive source for moving the guide shaft 23, but it is natural that these may be driven by separate motors. Further, the driving source is not limited to a motor, and for example, a plunger or the like may be used.

Furthermore, although a tension spring was used in the above-described embodiment as a biasing means for biasing the decal shaft 22 or guide shaft 23 in a direction that increases the decal effect, the present invention does not need to be limited to this. In addition to springs such as coil springs, compression springs, and springs, cylinders such as air cylinders and oil cylinders, or magnets may also be used.

Furthermore, although the above-mentioned recording system has been explained by taking as an example a thermal recording device using a heat-sensitive sheet material, the present invention can be similarly applied to a thermal transfer recording device that transfers ink from an ink sheet to plain paper.

<Effects of the Invention> As described above, in the present invention, the guide member or the decal member is configured to be movable by the interaction between the tension acting on the sheet material and the moving force applied to the guide member or the decal member. Curl correction can be performed depending on the degree of curl of the sheet.

In addition, since the moving torque is applied to the moving means according to the roll diameter of the sheet material, by reducing the moving torque when transitioning to the recording standby state, the load on the drive source such as the motor is reduced, and the VT position is fully maintained. The overall size can be reduced.

Furthermore, since the decal member or the guide member is biased by the biasing means, unnecessary load can be prevented from being applied to the drive source of the sheet conveying means, and sheet conveyance accuracy can be improved. In addition, it has features such as being able to reduce the cost by downsizing the drive source.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a first embodiment in which the present invention is applied to a recording system of a facsimile machine, FIG. 2 is an overall cross-sectional view of the facsimile machine, FIG.
Figures (a) and (b) are illustrations of curling of the sheet material, Figures 5 (a) and (b) are illustrations of the state in which recording is performed with a large-diameter sheet roll loaded, and Figures 6 (a) and (b). is an explanatory diagram of the state in which recording is performed using a small diameter sheet roll, Fig. 7 is an explanatory diagram showing the roll diameter and degree of curl, and Fig. 8 is an explanatory diagram showing the rotation angle θ of the guide member.
FIG. 9 (a) is a cross-sectional explanatory diagram showing the relationship between
), (b), and (C) are explanatory diagrams showing the configuration, and Figure 1O is a graph showing the relationship between the rotational angle θ and the rotational torque T.
1 and 12 are explanatory diagrams of the prior art. A is the decal mechanism, B is the recording system, C is the document reading system,
1 is the device body, 2 is the lid, 3 is the shaft, 4 is the roll holder, 5 is the sheet material, 5a is the sheet roll, 5b is the winding core, 6
is a recording means, 6a is a platen roller, 6b is a recording head, 6b+ is a heating element, 6c is a shaft, 6d is a compression spring, 7 is a cutter, 7a is a fixed blade, 7b is a driving blade, 7C is a shaft, 8
is a discharge roller, 9 is a stacker, 10 is a document placement table, 11
12a is a preliminary conveyance roller, 12b is a pressure contact member,
13a is a separation roller, 13b is a pressure contact member, 14a, 14
b, 15a15b is a conveyance roller, 16 is a light source, 17 is a mirror, 18 is a lens, 19 is a photoelectric conversion element, 20 is a motor, 21a to 21d are gears, 22 is a decal shaft, 23 is a guide shaft, 24 is a mounting member, 25 is the axis,
26 is an arm, 27 is a bearing, 28 is a clutch gear, 28
a + 30 a is the cylindrical part, 28b is the gear part, 29 is the spring clutch, 30 is the crank, 30b is the crank plate,
30c and 31 are projections, 32 is a tension spring, 33 is a stopper, and 34 is a guide.

Claims (7)

[Claims] (1) A conveying means for conveying the sheet material, a guide member for guiding the conveyance of the sheet material, a decal member for bending and guiding the conveyed sheet material, the guide member and the decal member A decurling mechanism comprising: a moving means for moving at least one of the above; and a biasing means for applying a moving torque to the moving means according to a roll diameter of the sheet material. (2) The decurling mechanism according to claim 1, wherein the device main body and the lid are configured to be openable and closable, the decal member is provided on the lid, and a guide member is provided on the device main body. (3) The decurling mechanism according to claim 1, wherein the self-holding force of the drive source for operating the moving means is set to be larger than the urging force applied to the moving means by the urging means. (4) The decurling mechanism according to claim 1, wherein the moving force of the moving means is set to be larger than the urging force of the urging means of the moving means. (5) A recording device comprising: the decurling mechanism according to claim (1); and recording means for recording an image on a sheet material conveyed by the conveyance means. (6) A cutter is provided downstream of the recording means in the sheet material conveying direction, and a driving source for the conveying means for conveying the sheet material and a driving source for operating the moving means are configured to be the same. , The amount of rotation of the drive source required to reverse feed the sheet material from the cutter to the recording means and the amount of rotation of the drive source required to return the moving means to the initial position are set to be approximately the same. The recording device according to claim (5). (7) In the case where the drive source for the conveyance means for conveying the sheet material and the drive source for operating the moving means are configured to be the same, and the output of the drive source is used to convey the sheet material in the recording direction. 6. The recording apparatus according to claim 5, wherein the recording apparatus is set to have a larger value when conveying in a direction opposite to the recording direction.