JP2640861B2 - Decal mechanism and recording apparatus using the decurl mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decurling mechanism for correcting the curl of a rolled sheet material and a recording apparatus having the decurling mechanism.

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

Since this sheet material is wound in a roll shape, it is easily wound (hereinafter referred to as “curl”), and the curled sheet material is likely to cause a jam when being conveyed.
For this reason, many recording apparatuses that use the roll sheet to remove or reduce the curl include a decurling mechanism.

As an example of the decurling mechanism, there is one configured as shown in FIG. 11, for example. The main body 51 and the lid 52 are configured to be openable and closable by pins 53, and a roll holder 54, a platen roller 55, a cutter 56 and a guide member 57a constituting a decurling mechanism are provided in one main body 51, and the other lid body is provided. 52 is provided with a guide member 57b that constitutes a decurling mechanism together with the recording head 58 and the guide member 57a.

In the above-described apparatus, a sheet roll 59a in which the sheet material 59 is wound in a roll shape is loaded, the sheet material 59 is conveyed by rotation of the platen roller 55, an image is formed by the recording head 58, and the image is cut by the cutter 56. When the sheet material 59 passes through a bent path formed by the guide members 57a and 57b, the sheet material 59 is curled when it is bent in a direction opposite to the curl.

As another example, there has been proposed a decurling mechanism configured as shown in FIG. This configuration is for guide shaft 60
Arms 61 are rotatably attached to both ends of the arm 61, and a decal shaft 62 is rotatably attached to the tip of the arm 61. The arm 61 is always urged counterclockwise by a spring, and when the platen roller 55 rotates in the direction of the arrow, the rotational force is transmitted through a friction clutch (not shown), and the arm 61 rotates clockwise. It is configured so that Further, stoppers 63 and 64 for limiting the rotation of the arm 61 are fixed to predetermined positions of the main body 51.

In the above configuration, when the platen roller 55 rotates in the direction of the arrow, the sheet material 59 is conveyed. At this time, arm 61
Also rotates clockwise, and when it comes into contact with the stopper 64, the friction clutch slips and the rotation of the arm 61 is stopped. The conveyed sheet material 59 is conveyed while being bent from the roll 59a via the guide shaft 60 by the decurling shaft 62 in the direction opposite to the curl, so that the curl is corrected.

When the rotation of the platen roller 55 is stopped, the arm 61 returns to the standby state until it comes into contact with the stopper 63 by the urging force of the spring.

<Problem to be Solved by the Invention> In the decurling mechanism shown in FIG. 11, the sheet material 59 between the guide members 57a and 57b is still folded even during the recording standby, so that the recording standby If the state is long, a reverse curl occurs in the sheet material 59 in the above-mentioned portion. Further, since the bending angle formed by the guide members 57a and 57b for performing the curl correction is always constant, there is a possibility that the curl that changes depending on the diameter of the roll 59a cannot be appropriately corrected.

In the decurling mechanism shown in FIG. 12, since the driving force for rotating the platen roller 55 is transmitted to the arm 61 via the friction clutch, the roller 55 is driven while the platen roller 55 is rotating. The frictional load of the friction clutch is always applied to the rotating motor. Accordingly, the required torque of the motor is also required to be larger than when only the platen roller 55 is rotated, and the motor is increased in size and causes an increase in cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a decurling mechanism capable of effectively correcting a curl without imposing an unnecessary load on a conveying means for conveying a sheet material, and a recording apparatus having the decurling mechanism. It is in.

<Means for Solving the Problems> A representative means of the present invention for solving the above problems is:
Conveying means for conveying the sheet material, a guide member for guiding the conveyance of the sheet material, a decurling member for bending and guiding the conveyed sheet material, and at least one of the guide member and the decurling member A decurling mechanism is provided by providing moving means for moving the sheet member and urging means for urging the moving means in a direction in which the bending of the sheet material is increased.

<Operation> In the above means, when the sheet material is conveyed, 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 urging force on the moving means is small, and the amount of operation of the moving means is small, so that the amount of bending of the sheet material is small. On the other hand, when the tension is small, the amount of movement of the moving means is increased and the amount of bending of the sheet material is increased, contrary to the above. Thereby, the curl correction according to the curl strength is performed.

Further, since the urging of the moving means is performed by the urging means, a load for operating the moving means is not applied to the transport means.

Further, by providing the guide member and the decal member separately in the apparatus main body and the lid, when the lid is opened, the guide member and the decal member are largely separated from each other, so that the sheet material can be easily loaded. .

Further, by making the moving force of the moving means larger than the urging force of the urging means to the moving means, the moving means can be operated in a direction in which the sheet material does not bend against the urging of the urging means, In the conveyance standby state, the sheet material can be prevented from being decurled more than necessary.

Further, by increasing the self-holding force of the driving source of the moving means to some extent, the relationship between the guide member and the decurling member can be appropriately maintained.

Further, when the recording device is configured by providing the decurling mechanism, the transport unit and the moving unit are operated by the same driving source, and the driving source is driven to reversely feed the sheet material from the cutter to the recording unit. By returning the moving means to the initial position, the moving means always comes to the initial position in the recording standby state.

Further, by setting the output of the drive source to be larger in a case where the sheet material is conveyed in a direction opposite to the recording direction than in a case where the sheet material is conveyed in the recording direction, the sheet material can be stably conveyed. It is.

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

(First embodiment)

1 and 2 are perspective explanatory views of a recording system of the facsimile apparatus, and FIG. 3 is a sectional explanatory view of the entire facsimile apparatus.

This facsimile apparatus includes a recording system B having a decurling mechanism A and a document reading system C as shown in FIG.

First, the overall configuration will be briefly described with reference to FIG. 3. The recording system B is configured such that a lid 2 can be opened and closed by a shaft 3 on a main body 1 of the apparatus. It is constituted so that it can be locked. A roll holder 4 is provided at a predetermined position on the back side of the recording system main body, and a roll 5a of a heat-sensitive sheet material 5 wound in a roll shape is loaded in the holder 4. The sheet material 5 is conveyed by rotation of a platen roller 6a constituting a conveying means. At this time, when the sheet material 5 passes through the decurling mechanism A, the sheet material 5 is bent in a direction opposite to the curl direction to correct the curl.

The curl-corrected sheet material 5 is configured such that a predetermined image is formed in a recording unit 6, and the sheet material 5 after recording is cut by a cutter 7 and discharged to a discharge stacker 9 by a discharge roller 8. I have.

The document reading system C sets a plurality of documents 11 on a document table 10 formed on the upper surface of the lid 2 and performs a reading operation. 2 are transported by a preliminary transport roller 12a and a pressure contact member 12b pressed against the preliminary transport roller 12a, and separated and supplied one by one by a separation roller 13a and a pressure contact member 13b pressed against the separation roller 13a. The further separated document 11 is transported
While being conveyed by 14a, 14b and 15a, 15b, light is radiated by the light source 16, and the reflected light is transmitted through the mirror 17 and the lens 18.
It reaches the photoelectric conversion element 19 such as a CCD and is converted into an electric signal.
This signal is transmitted to its own recording system B in the copy mode, and is transmitted to the recording system of another machine in the facsimile mode.

Next, the configuration of each part of the recording system B having the decurling mechanism A in the facsimile apparatus will be described in detail.

The roll holder 4 is formed in a shape whose upper part is open, and this is arranged on the back side of the recording system main body 1. The roll holder 4 is loaded with a sheet roll 5a, and the outer peripheral surface of the roll 5a comes into contact with the inner surface of the holder 4 to generate frictional resistance. That is, when the sheet material 5 is pulled out, the diameter of the roll 5a is large, and when the sheet material 5 is heavy, a large frictional resistance is generated.
As the weight decreases, the frictional resistance also decreases. This frictional resistance has the effect of imparting tension to the sheet material 5 when the sheet material 5 is pulled out, and the tension applied to the sheet material 5 pulled out also changes in proportion to the magnitude of the frictional resistance.

The configuration of the recording means 6 for recording a predetermined image on the sheet material 5 includes a platen roller 6a and a recording head 6b. The platen roller 6a is formed by forming a member having a high friction coefficient such as hard rubber into a roller shape and rotatably attached to the main body 1. The platen roller 6a is configured to be driven by a motor 20 serving as a driving source. I have. That is, as shown in FIG. 1, the rotational force of the motor 20 is applied to the gear 21 fixed to the motor shaft.
is transmitted from a to the gear 21c fixed to the roll shaft of the platen roller 6a via the intermediate gear 21b, and the platen roller 6a rotates. The sheet material 5 is conveyed by the rotation of the platen roller 6a, and the platen roller 6a also functions as a conveying means of the sheet material 5.

The recording head 6b forms an image on the sheet material 5 by heating the sheet material 5 in accordance with an image signal, and is configured to press the platen roller 6a via the sheet material 5. Specifically, the cover 2 is rotatably attached to the lid 2 by a shaft 6c, and is configured such that the platen roller 6a is pressed by a compression spring 6d when the lid 2 is closed. Therefore, when the platen roller 6a rotates while the sheet material 5 is inserted between the platen roller 6a and the recording head 6b, the sheet material 5 is conveyed.

On the surface in the recording head 6b in the present embodiment is in contact with the sheet material 5, a large number of heating elements 6b ₁ which generates heat by energization and arranged in the width direction of the sheet material 5, by using the so-called line type thermal head And selectively heating the sheet material 5 by applying current to the heating element 6b ₁ in accordance with an image signal,
The recording is performed by coloring the heat-sensitive sheet material 5.

Next, in this embodiment, a rotary cutter composed of a fixed blade 7a and a driving blade 7b is used as the cutter 7. Specifically, the fixed blade 7a is fixed to the main body 1, and the driving blade 7b is rotatably mounted around a shaft 7c. When the driving blade 7b is rotated by a driving unit, the driving blade 7b rubs against the fixed blade 7a. This is for cutting the sheet material 5.

The driving blade 7b may be driven by a motor 20 for driving the platen roller 6a, or may be driven by another independent motor.

The sheet material 5 cut by the cutter 7 is stacked by a discharge roller 8 driven by driving means (not shown).
However, since the sheet material 5 used for the recording is wound around the core 5b, the sheet material 5 is curled when pulled out from the sheet roll 5a.

The curl varies depending on the diameter of the roll 5a. For example, the curl generated when the roll diameter is large is small in the curl height h shown in FIG. 4A, and when the roll diameter is small, the curl height h is large and further shown in FIG. 4B. Curled up like that.

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 decurl member,
The curl is corrected by bending the sheet material 5 in the direction opposite to the curl direction when guided by the shafts 22 and 23.

Further, the guide shaft 23 is urged by the urging means to be described later on the sheet material 5, and the guide shaft 23 is loaded with the large-diameter roll 5a as shown in FIG. 5 and when the small-diameter roll 5a is loaded as shown in FIG. The decal effect is different.

Here, the configuration of the decurling mechanism A will be specifically described.

The decal shaft 22 is rotatably mounted on a mounting member 24 fixed to the lid 2 as shown in FIGS. The mounting member 24 is a flat plate serving as a guide for the sheet material 5.
24a and brackets 24b formed upright at both ends of the flat plate 24a.
The distance between the two brackets 24b is larger than the width of the sheet material 5, and a guide shaft 23 to be described later is formed.
Are formed smaller than the interval between the arms supporting both ends of the arm. Then, the decal shaft 22 is attached to the bracket 24b.
Is rotatably mounted.

As shown in FIGS. 5 and 6, the position of the decal shaft 22 with respect to the main body 1 when the lid 2 is closed is always constant, and the position at this time is relative to the platen roller 6a. It is disposed on the upstream side in the transport direction and at a position where the introduction angle of the sheet material 5 to the platen roller 6a is not so large.

The sheet material 5 pulled out from the roll 5a is placed on the platen roller 6a on the main body 1 facing the decal shaft 22.
A guide 37 for guiding up to is provided. One end of the guide 37 is extended 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 configured to be movable with respect to the decal shaft 22 by a moving means. As shown in the perspective explanatory view of FIG. 7 and the sectional explanatory view of FIG.
The arms 26 are fixedly mounted, and a guide shaft 23 is rotatably attached to the distal ends of both arms 26. When the shaft 25 rotates, the arms 26 rotate integrally, whereby the guide shaft 23 with respect to the decal shaft 22 is rotated. Is movable.

The shaft 25 is rotatably mounted on the main body 1 via a bearing 27. A clutch flange 28, a clutch gear 29 and a spring clutch 30 are mounted on one shaft end, and a rotational force is transmitted to the shaft 25 in one direction. It is constituted so that it may be performed.

The clutch flange 28 includes a cylindrical portion 28a and a flange portion 28b, and is attached by a locking pin 31 so as to rotate integrally with the shaft 25 in the same direction.

The clutch gear 29 includes a cylindrical portion 29a and a gear portion 29b. The inner diameter of the hole through which the shaft 25 is inserted is formed slightly larger than the outer diameter of the shaft 25, and the clutch gear 29 is rotatably attached to the shaft 25. I have.

The spring clutch 30 is formed by winding a spring steel wire, a spring steel strip, a plastic wire, or the like in a coil shape, and forms both the cylindrical portions 28a, 29 of the clutch flange 28 and the clutch gear 29.
It is wound around the outer periphery of a, and one end thereof is engaged with a flange 28b of the clutch flange 28.

The spring clutch 30 transmits the rotational force of the clutch gear 29 to the clutch flange 28 only in one direction and does not transmit the rotational force in the other direction. That is, when the clutch gear 29 rotates in the direction of arrow a in FIG. 7, the spring clutch 30 is loosened and becomes free, and no torque is transmitted to the clutch flange 28. On the other hand, when the clutch gear 29 rotates in the direction indicated by the arrow -a opposite to the above (the minus sign indicates the opposite direction of the arrow), the spring clutch 30 tightens the cylindrical portions 28a, 29a to be in a locked state, and the clutch flange is locked. The rotational force is transmitted to 28 and the rotational force for moving the guide shaft 22 in the direction of arrow b is transmitted.

The driving source for rotating the clutch gear 29 is the same as the driving source for rotating the platen roller 6a, and is driven by the motor 20. That is, as shown in FIG. 1, the driving force of the motor 20 is transmitted to the platen roller 6a through the gears 21a to 21c as described above, but the gear 21c attached to the platen roller shaft is transmitted through the intermediate gear 21d. It is in mesh with the gear portion 29b of the clutch gear 29.

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 29 rotates in the direction of arrow a. That is, when the platen roller 6a rotates in a direction to pull out the sheet material 5 in the direction of arrow e, the spring clutch 30 is in a free state.

When the motor 20 rotates in the reverse direction of the arrow -c, the platen roller 6a rotates in the direction to feed the sheet material 5 in the reverse direction. At this time, the clutch gear 29 rotates in the direction of the arrow -a, and the spring clutch 30 rotates. Are locked, and transmit a rotational force for rotating the guide shaft 23 in the direction of the arrow b in FIG.

Next, the structure of the urging means for urging the guide shaft 23 so as to balance the tension of the sheet material 5 will be described.

A locking pin is provided at the other end of the shaft 25 as shown in FIGS.
A pulley 33 is fixed by 32. A groove 33a is formed on the circumferential surface of the pulley 33, and a hook 34a is protruded at a predetermined position. The hook 34a and a hook 34b protruded at a predetermined position of the main body 1 (see FIG. 2). And a tension spring 35 is attached with a tension. That is, the pulley 33 is always urged in the direction of arrow f in FIG. 7 (the direction in which the decurling effect by the guide shaft 23 increases) by the tensile force of the tension spring 35.

Further, a stopper 36 is provided at a predetermined position of the main body 1 and in a rotation range of the arm 26. The stopper 36 comes into contact when the arm 26 rotates in the direction of the arrow -b in FIG. 7, and restricts the amount of rotation of the arm 26 so that the maximum value of the amount of winding of the sheet material 5 around the decal shaft 22 is reduced. To set.

Next, the operation when recording is performed using the recording system B having the decurling mechanism A configured as described above will be described when the roll diameter is large as shown in FIG. 5 and when the roll diameter is small as shown in FIG. A description will be given mainly of the curl correcting action of the present invention.

First, the cover 2 is opened to load the sheet roll 5a into the roll holder 4, and the leading end of the sheet is pulled out to the platen roller 6a and set. At this time, the decal shaft 22 is attached to the lid 2 as shown in FIGS.
Since the guide shaft 23 is attached to the main body 1, when the lid 2 is opened, the two shafts 22 and 23 are largely separated so that the sheet material 5 can be easily set.

Next, when a recording start signal is input with the lid 2 closed, the motor 20 rotates forward, the platen roller 6a rotates in the direction of arrow d, and the sheet material 5 is conveyed in the direction of arrow e. Predetermined recording is performed on the sheet material 5 by heating the heating elements 6b ₁ or selectively recording head 6b in synchronization with the conveyance. 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 29, but as described above, the spring clutch 30 is in a free state, and the clutch gear 29 idles with respect to the clutch flange.

On the other hand, since the urging force in the direction of arrow f is acting on the shaft 25 by the tensile force of the tension spring 35 as shown in FIG. 7, the arm 26 rotates in the direction of arrow -b and the guide shaft 23 moves. Then, it stops at a position balanced with the tension of the sheet material 5.

As a result, the sheet material 5 is conveyed from the sheet roll 5a around the guide shaft 23 in the curl direction, then bent by the decurl shaft 22 and wound around the shaft 22 in a direction opposite to the curl direction. The curl of the sheet material 5 is corrected by the winding around the decurl shaft 22.

Here, contact tension between the roll holder 4 and the roll 5a loaded in the holder 4 acts on the tension applied to the conveyed sheet material 5. That is, as shown in FIG. 5, the weight of the roll 5a and G _1, this time the tension acting on the seat member 5 and F _1, the tension F ₁ along the sheet material 5 before and after the guide shaft 23 Works.
The guide shaft 23 is increased is wound amount of the sheet material 5 with respect to the shaft 23 by moving the arrow -b direction tensile rotational force (tension spring 35 of the arm 26 with respect to the resultant force of the tension F ₁ in accordance with this The resistance to the force (rotational torque of the pulley 33) increases. And the resultant force and arm
The arm 26 stops at a position where the turning power of 26 is balanced.

As shown in FIG. 5, the tension F ₁ and winding angle sheet material 5 is wound to the decurling shaft 22 when the rotational force of the arm 26 are balanced is theta ₁ becomes relative to the seat member 5 when the roll diameter is large , And then guided to the platen roller 6a.

On the other hand, when the diameter of the roll 5a as shown in FIG. 6 is smaller roll weight G ₂ becomes small (G ₂ <G _1), the tension F ₂ acting on the sheet material 5 is also reduced (F ₂ <F ₁₎ . For this reason, the arm 26 has an arrow -b further than the case where the roll diameter is large.
Rotate in the direction. When the rotational force of the arm 26 and the drag are balanced, the arm 26 stops at that position,
If the amount of rotation of the arm 26 is larger, the stopper 36
Stop at the position where it abuts. In this case the winding angle sheet material 5 is wound to the decurling shaft 22 is theta ₂ becomes smaller than the winding angle theta ₁ when the roll diameter is large.

Therefore, when the diameter of the roll 5a is large, the winding amount of the sheet material around the decurling shaft 22 is small, and the winding amount increases as the roll diameter decreases and the curl increases. As the amount of winding increases, the sheet material 5 is bent in the direction opposite to the curl, so that the curl correcting effect increases. That is, the curl correcting effect increases as the roll diameter at which the curl increases becomes smaller.

Here, the results of an experiment in which the sheet material 5 having various roll diameters is conveyed by the decurling mechanism A to correct the curl are shown.

The sheet material 5 used in this experiment was a sheet roll 5a in which a thermosensitive recording paper having a width of 210 mm (A4 size) and a length of 100 m was wound around a 1-inch (25.4 mm) core 5b. in this case,
When the sheet was not used, the diameter of the roll 5a was 96 mm. In addition, the tension spring 35 is set so that the turning power of the arm 26 is 1 kgcm, the moving radius of the guide shaft 23 is set to 13 mm,
The decal shaft 22 used had an outer diameter of 4 mm. Further, the sheet material 5 is configured so that the range of the winding angle θ at which the sheet material 5 is wound around the decal shaft 22 is 130 to 30 degrees.
mm (A4 size length) was conveyed and the result was observed.

The results of the experiment were as shown in FIG. In FIG. 9, the white triangles show the curl shape in FIG. 4A without curl correction, and the black triangles show the curl shape without curl correction in FIG. (B)
It has become. The white circles are the ones which have been curled by the decurling mechanism A and whose curl state is as shown in FIG. 4 (a).

As is clear from this result, the curl generated in the sheet material 5 is such that the larger the diameter of the roll 5a, the smaller the value of the curl height h, and the smaller the roll diameter, the larger the value of the curl height h. When the roll diameter becomes about 40 mm or less, curling in a rolled state occurs.

On the other hand, the sheet material 5 decurled by the decurling mechanism A of the above-described embodiment hardly generates curl, and the value of the measured curl height h showed a substantially constant value.

As described above, the decurling mechanism A changes the decurling effect according to the strength of the curl by the balance between the tension acting on the sheet material 5 and the rotational power of the arm 26, and appropriately corrects the curl.

The arm 26 is urged by a tension spring 35, and the rotational force of the motor 20 in the direction c is applied to the platen roller 6a.
, But not to the arm 26. Therefore,
Since a load for moving the arm 26 is not applied to the motor 20 at the time of recording, the transport accuracy is improved and high-quality recording can be performed.

After recording the image on the sheet material 5 whose curl has been corrected as described above, the image is cut by the cutter 7 and discharged by the discharge roller 8.

On the other hand, the leading end of the sheet material 5 in the apparatus is fed backward by a distance 1 from the position of the cutter 7 to the recording means. This is to prevent a blank portion from being formed at the leading end of the sheet during the next recording. Therefore, when the motor 20 is reversely driven by a predetermined amount, the driving force is transmitted not only to the platen roller 6a but also to the clutch flange 28 by locking the spring clutch 30 as described above, thereby rotating the arm 26 in the direction of arrow b. Force acts.

At this time, as shown in FIG. 7, a tension force acts on the arm 26 in a direction in which the rotation is hindered by a tension spring 35. For this reason, the driving force of the motor 20 in the present embodiment at the time of reverse rotation driving is set to be larger than the arm rotation force due to the pulling force of the pulling spring 35 as described above.

Therefore, when the motor 20 is driven in reverse to feed the sheet material 5 in the reverse direction as described above, the arm 26 rotates in the direction of arrow b by the driving force and separates from the sheet material 5, as indicated by the two-dot chain line in FIG. Return to the indicated initial position. Here, the initial position is a position where the guide shaft 23 does not block the opening of the roll holder 4, and the guide shaft 23 is opened when the lid 2 is opened.
23 is a position where it does not interfere with the decal shaft 22. In this state, since the guide shaft 23 is separated from the sheet material 5, even if the recording standby state continues for a long time, the sheet material 5 is not curled in the opposite direction.

A motor is used to reversely feed the sheet material 5 by a distance l.
The amount by which the arm 26 rotates (return angle α) when the 20 is rotated in the reverse direction is set to an angle at which the arm 26 rotates from the position in contact with the stopper 36 to the initial position as shown in FIG. .

That is, the motor for rewinding the sheet material 5 by the length l
In order that the rotation amount of the motor 20 and the rotation amount of the motor 20 when the arm 26 is rotated by the angle α in the direction of the arrow b are the same,
The distance 1 between the platen roller 6a and the cutter 7, the rotation ratio between the platen roller 6a and the shaft 25, the position of the stopper 36, and the like are set.

Next, the motor driving force required to operate each member when the motor 20 is driven forward and when it is driven reversely will be described.

When the case of normal rotation of the motor 20 to the motor output (when conveying the sheet material 5 to the recording direction) and P _1, in the spring clutch 30 in this case becomes a free state, the output P ₁ is a platen roller The driving force required to rotate 6a is sufficient.

On the other hand, when the motor output when (when transporting direction to rewind the sheet material 5) to reverse driving motor 20 and P _2, in the spring clutch 30 in this case becomes the locked state, the output P ₂ is A driving force required to rotate the platen roller 6a and a driving force required to rotate the arm 26 against the tension spring 35 are required, and a driving force (P ₁ <P ₂₎ is required.

Setting the rated output of the for motor 20 to the P _2, when conveying the sheet material 5 to a recording direction of the motor 20 and driven to rotate forward, the excess output of the motor 20 (P ₂ -P ₁₎ is caused Vibration may occur, leading to uneven feed and noise.

Therefore, in the present embodiment sets the output at the time of normal rotation driving motor 20 in the P _1, when driven in reverse to drive so that the large output P ₂ than during normal rotation. This can be easily achieved by a known method such as increasing the drive current of the motor 20 at the time of reverse rotation with respect to the time of forward rotation, or reducing the number of rotations.

Even if the driving current is increased or the number of rotations is set low during the reverse rotation driving as described above, the rewinding amount l (for example, 20 mm) with respect to the recording transport amount (for example, 210 mm for A4 size) of the sheet material 5 ) Is sufficiently small, the effect of the temperature rise of the motor 20 during the reverse rotation driving or the delay of the reverse feeding time of the sheet material 5 is extremely small.

Further, it is preferable to set the gear ratio and the like so that the rotation speed of the arm 26 driven by the drive of the motor 20 is equal to or slightly higher than the rotation peripheral speed of the platen roller 6a (conveyance speed of the sheet material 5). That is, the guide shaft 23 is quickly retracted to the initial position when the sheet material 5 is reversely fed by the above configuration.

The motor 20 is stopped after rewinding the sheet material 5 by a predetermined amount.
It is being pulled by 35. As shown in FIG. 7, this pulling force becomes a force for urging the clutch gear 29 in the direction of arrow a by locking the spring clutch 30 in order to rotate the pulley 33 in the direction of arrow f. This acts as a rotation torque for rotating the motor 20 via the gears 21a to 21d.

For example, if the rotation torque for rotating the pulley 33 in the direction of arrow f is T ₁ (for example, about ₁ kgcm), and the rotation speed ratio between the motor 20 and the clutch gear 29 is 10: 1, the rotation power causes the motor 20 to rotate. rotational torque T ₂ /10(0.1kg transmitted
cm).

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 (the magnetic force or the like when the torque is externally applied to the rotor composed of the permanent magnet). It is set larger (e.g. 0.2Kgcm) than the rotational torque T ₂ to be transmitted torque) which the rotor is to rest on the motor 20 by.

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.

Therefore, the guide shaft 23 does not interfere with the decal shaft 22 when the cover 2 is opened, for example, when the roll 5a is replaced, and the cover 2 can be opened smoothly.

Since the apparatus according to the present embodiment is configured as described above, the curl correction can be performed according to the curl strength, and the load applied to the motor 20 during recording is a platen roller.
Since only the load for rotating 6a is used, the sheet is accurately conveyed, and the roll 5a can be easily replaced.

(Second embodiment)

In the above-described first embodiment, an example in which the guide shaft 23 is made movable with respect to the decal shaft 22 is shown, but an embodiment in which the decal shaft 22 is made movable as a second embodiment is shown in FIG. .

The same portions and portions having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 10, the guide shaft 23 is rotatably attached to a support member 38 of the apparatus main body 1.

On the other hand, the decurling shaft 22 is rotatably mounted on an arm 40 fixed to a shaft 39 rotatably mounted on the lid 2, and the curl of the sheet material 5 is corrected by rotating the arm 40 in the direction of arrow g. The correction is released by rotation in the -g direction.

At one end of the shaft 39, a clutch gear 42 to which an electromagnetic clutch 41 is fixed is rotatably provided. The electromagnetic clutch 41 transmits or releases the rotational force of the clutch gear 42 to the shaft 39 according to a signal from a control unit (not shown). A gear 44 fixed to a motor 43 meshes with the clutch gear 42 so that the driving force of the motor 43 is transmitted to the clutch gear 42.

The other end of the shaft 39 has a pulley 45 as in the first embodiment.
Is fixed, and a tension spring 47 is attached between a protrusion provided on the circumferential surface of the pulley and a knock 46 protruding at a predetermined position of the lid 2, and the arm 40 is operated by the action of the spring 47. Are always provided in the direction of arrow g.

In the above-described configuration, at the time of recording standby, the electromagnetic clutch 41 is used.
Is in the ON state, and the arm 40 is held at the position shown by the two-dot chain line in FIG. 10 by the self-holding force of the motor 43. Therefore, when the cover 2 is opened, the roll 5a can be easily replaced without interference between the decal shaft 22 and the guide shaft 23.

At the time of recording, the cover 2 is closed, the motor 20 is driven, the platen roller 6a is rotated to convey the sheet material 5 in the direction of the arrow e, and the recording head 6b is driven according to the image signal to form the sheet material 5. Form an image. At this time, when the electromagnetic clutch 41 is turned off at the same time as the driving of the motor 20, the arm 40 rotates in the direction of arrow g due to the pulling force of the pulling spring 47, and the decal shaft 22 is seated as shown by the solid line in FIG. Contact with material 5. This decal shaft 22
Is moved to a position where the urging force of the tension spring 47 and the tension of the sheet material 5 are balanced as in the first embodiment, and the sheet material 5 is bent by the decurling shaft 22 in the direction opposite to the curling direction, thereby curling. Is to be corrected.

When the recording is completed, the motor 20 is driven to rotate in the reverse direction, and the leading end of the sheet material 5 is fed backward from the cutter 7 to the position of the platen roller 6a. At this time, the electromagnetic clutch 41 is turned on, and the motor 43 is reversely driven by a predetermined amount to rotate the arm 40 in the direction of the arrow -g. The rotation amount α of this arm is the same as in the first embodiment. As a result, the sheet 40 returns to the position indicated by the two-dot chain line in FIG. 10 and is held at that position.

Even if the decal shaft 22 is movable as described above,
The same effects as in the first embodiment can be obtained.

[Other embodiments]

In the above-described first embodiment, the guide shaft 23 is attached, and in the second embodiment, the decal shaft 22 is attached to each arm,
The arm is configured to move by rotating the arm. However, the moving means is not limited to this. For example, as another structure, the guide shaft 23 or the decal shaft 22 is moved in parallel along a rack or a rail. Such a configuration may be adopted, and the moving may be performed by pushing up with a cam or the like.

Further, both the decal shaft 22 and the guide shaft 23 may be configured to be movable by combining the first embodiment and the second embodiment.

Further, the decal shaft 22 and the guide shaft 23 may be fixed to the mounting member 24 and the arm 26, respectively, and may be formed of a metal plate or the like bent to have a predetermined radius of curvature instead of the metal shaft. It is possible.

Further, as a device for selectively transmitting the driving force of the motor to the decal shaft 22 or the guide shaft 23, the spring clutch 30 is used in the first embodiment, and the electromagnetic clutch 41 is used in the second embodiment. Without limitation, for example, a roller type needle clutch or the like may be used.

In the first embodiment, a motor for driving the platen roller 6a is used as a drive source for moving the guide shaft 23.
Although 20 was used, it is obvious that these may be driven by separate motors. Further, the drive source does not need to be limited to a motor, and for example, a plunger or the like may be used.

Further, in the above-described embodiment, a tension spring is used as the urging means for urging the decal shaft 22 or the guide shaft 23 in a direction to increase the decurling effect. However, the present invention is not limited to this. In addition to a coil spring, a compression spring, a spring such as a mainspring, cylinders such as an air cylinder and an oil cylinder, or a magnet may be used.

Further, the above-described recording system has been described by taking a thermal recording apparatus using a thermal sheet material as an example. However, the present invention can be similarly applied to a thermal transfer recording apparatus that transfers ink from an ink sheet to plain paper. .

<Effects of the Invention> As described above, the present invention is configured such that the guide member or the decal member can be moved by the interaction between the tension acting on the sheet material and the moving force applied to the guide member or the decal member. The curl can be corrected according to the degree of curl of the sheet.

Further, since the decal member or the guide member is urged by the urging means, it is possible to prevent an unnecessary load from being applied to the driving source of the sheet conveying means, to improve the sheet conveying accuracy, and to reduce the driving force. The feature is that the size of the source can be reduced and the cost can be reduced.

[Brief description of the drawings]

1 and 2 are perspective explanatory views of a first embodiment in which the present invention is applied to a recording system of a facsimile apparatus, FIG. 3 is an overall sectional explanatory view of the facsimile apparatus, and FIG. FIG. 5, FIG. 5 is an explanatory diagram showing a state in which recording is performed by loading a large-diameter sheet roll, FIG. 6 is an explanatory diagram showing a state in which recording is performed using a small-diameter sheet roll, and FIG. 7 and FIG. , FIG. 9 is an explanatory view showing the roll diameter and the degree of curl, FIG. 10 is an explanatory view of the second embodiment, FIG. 11 and FIG.
The figure is an explanatory view of the prior art. A is a decal mechanism, B is a recording system, C is a document reading system,
1 is an apparatus main body, 2 is a lid, 3 is a shaft, 4 is a roll holder, 5 is a sheet material, 5a is a sheet roll, 5b is a core, 6 is a recording means, 6a is a platen roller, 6b is a recording head, 6b ₁
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 drive blade, 7c is a shaft, 8 is a discharge roller, 9 is a stacker, 10 is a document placing table, 11 is a document, 12a is a preliminary transport roller, 12b is a pressure contact member, 13a is a separation roller, and 13b is a separation roller. Pressing members, 14a, 14b, 15a, 15b are transport rollers, 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, and 23 is a guide. Shaft, 24 is a mounting member, 24a is a flat plate, 24b is a bracket, 25 is a shaft, 26 is an arm, 27 is a bearing, 28 is a clutch flange, 28a is a cylindrical portion, 28b is a flange portion, 29 is a clutch gear, 29
a is a cylindrical portion, 29b is a gear portion, 30 is a spring clutch, 31 and 32 are locking pins, 33 is a pulley, 33a is a groove, 34a and 34b are hooks, 35
Is a tension spring, 36 is a stopper, 37 is a guide, 38 is a support member, 39 is a shaft, 40 is an arm, 41 is an electromagnetic clutch, 42 is a clutch gear, 43 is a motor, 44 is a gear, 45 is a pulley, and 46 is a hook. , 47 are tension springs.

Claims (7)

(57) [Claims] A conveying member for conveying the sheet material; a guide member for guiding the conveyance of the sheet material; a decurling member for bending and guiding the conveyed sheet material; A decurling mechanism, comprising: moving means for moving at least one of the decurling members; and urging means for urging the moving means in a direction in which the bending of the sheet material increases. 2. The decal according to claim 1, wherein the apparatus main body and the lid are configured to be openable and closable, the decal is provided on the lid, and a guide member is provided on the apparatus main body. mechanism. 3. The decal according to claim 1, wherein a self-holding force of a driving source for operating said moving means is set to be larger than an urging force applied to said moving means by said urging means. mechanism. 4. The decurling mechanism according to claim 1, wherein the moving force of said moving means is set to be larger than the urging force of said moving means by said urging means. 5. A recording apparatus comprising: the decurling mechanism according to claim 1; and recording means for recording an image on a sheet material conveyed by the conveying means. 6. A cutter is provided downstream of the recording means in the sheet material conveyance direction, and a drive source of the conveyance means for conveying the sheet material and a drive source for operating the movement means are the same. The rotation amount of the drive source required to reversely feed the sheet material from the cutter to the recording unit and the rotation amount of the drive source required to return the moving unit to the initial position are set to be substantially the same. The recording apparatus according to claim 5, wherein: 7. A driving source for conveying means for conveying the sheet material and a driving source for operating the moving means are configured to be the same, and the output of the driving source is conveyed in the recording direction of the sheet material. 6. The recording apparatus according to claim 5, wherein a case where the sheet is conveyed in a direction opposite to the recording direction is set to be larger than a case where the sheet is conveyed.