JPH04144767A - Uncurler and recorder employing uncurler - Google Patents

Abstract

PURPOSE:To prevent oblique advance of a recording sheet from a sheet roll by a constitution wherein a press member is energized by an energizing means to move, even upon fluctuation of winding diameter, and press a sheet roll against a holding member. CONSTITUTION:A thermal recording sheet 1, which develops a color thermally, is wound into a sheet roll 1b which is held by a holding member 2. A press member 3 for pressing the sheet roll 1b against a roll holder 2 is fixed rotatably around a shaft 4, and an uncurl member 5 for the recording sheet 1 is fixed rotatably at the rotary end of the press member 3. An energizing means 6 for bringing the press member 3 into pressure contact with the sheet roll 1b is coupled to the shaft 4 side of the press member 3. According to this constitution, the recording sheet 1 is prevented from oblique advance by pressing the sheet roll 1b against the holding member 2 even upon fluctuation of the winding diameter.

Description

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

<Conventional technology> Office equipment such as facsimile machines and printers have been widely used in the past, but the recording systems of these devices generally use sheet rolls in which long recording sheets are wound around a core. .

Since the above-mentioned recording sheet is wound into a roll, it is easily curled (hereinafter referred to as r-curl J), and curled recording sheets can cause jams (paper jams) when being transported.
becomes more likely to occur. For this reason, many of the recording apparatuses using the sheet roll are equipped with a so-called decurling mechanism that is equipped with a curl correction member for correcting or reducing curl. This decal mechanism will be illustrated below.

First, as shown in FIG. 6, an apparatus main body 50 and a lid 51 are configured to be openable and closable with a bottle 52, and a roll holder 53. Platen roller 54. cutter 55
．． A guide member 56a that constitutes a decurling mechanism is provided, and the lid body 51 is provided with a guide member 56b and a recording head 57 that constitute the decurling mechanism together with the guide member 56a.

In the recording apparatus described above, a sheet roll 58a having a recording sheet 58 wound therein is loaded into a roll holder 53, and the recording sheet 58 is conveyed by rotation of the platen roller 54. At this time, recording sheet 5
8 is bent in the opposite direction to the curl when passing through the bending path formed by the guide members 56a and 56b, thereby reducing the curl and conveying it to the recording head 57. and,
An image is formed on the recording sheet 58 by the recording head 57 according to the recording information, and the image is cut from the trailing edge by the cutter 55 and discharged from the apparatus.

FIG. 7 shows another embodiment, in which an arm 60 is rotatably attached to both ends of a guide shaft 59, and a decal shaft 61 is rotatably attached to the rotatable tip of this arm 60. There is.

The arm 60 is always biased counterclockwise by a spring (not shown), and when the platen roller 54 rotates in the direction of the arrow, the rotational force is transmitted through a friction clutch (not shown), and the arm 6o is biased clockwise. It is configured to rotate. Further, a stopper 62 for restricting the rotation of the arm 60 is provided at a predetermined position on the main body 500 of the apparatus.
63 are provided.

In the recording apparatus described above, when the platen roller 54 rotates in the direction of the arrow, the recording sheet 58 is conveyed.

At this time, when the arm 60 rotates clockwise and comes into contact with the stopper 63, the friction clutch slips and the arm 600 rotates clockwise.
Stop rotation. As a result, the recording sheet 58 is conveyed from the sheet roll 58a through the guide shaft 59 and bent in the opposite direction to the curl by the decurling shaft 61, so that the curl is corrected.

When the rotation of the platen roller 54 stops, the arm 60 rotates counterclockwise due to the biasing force of the spring, comes into contact with the stopper 62, and stops.

<Problems to be Solved by the Invention> However, in the decurling mechanism shown in FIG. 6, the recording sheet 58 between the guide members 56a and 56b remains folded even during recording standby. If the recording standby state is long, curls will occur in the opposite direction. Furthermore, since the bending angle formed by the guide members 56a and 56b for correcting curls is always constant, there is a risk that curls may not be properly corrected due to changes in the winding diameter of the sheet roll 58a.

In addition, in the decurling mechanism shown in FIG. 7, the curl straightening force is adjusted via a friction clutch, so the setting of the straightening force is delicate due to changes in the winding diameter, and the torque of the friction clutch varies. management etc. is difficult.

Further, when stacking the recording sheets 58 after recording, considering the order, it is convenient to convey the recording sheets 58 with the printed side facing down as shown in FIG. Therefore, the platen roller 5
4 to convey the recording sheet 5B, the sheet roll 58a rotates in the direction of arrow A in the figure and tends to roll in the direction of arrow B as a whole. Since the direction of arrow B is opposite to the direction of arrow C in which the recording sheet 58 is pulled out, the movement of the sheet roll 58a becomes extremely unstable. Particularly in facsimile machines, the conveyance operation is intermittent, which may cause rumbling noises or the sheet roll 5.
When the winding diameter of the recording sheet 8a becomes smaller and the weight becomes lighter, the position of the sheet roll 58a becomes unstable, and there is a risk that the recording sheet 58 will be skewed, jammed, etc.

Further, when the recorded recording sheet 58 is reversely fed after being cut, there is little room for the recording sheet 58 to escape, and there is a risk that curling may occur in the standby state (at the middle point in the figure).

An object of the present invention is to solve the problems of the prior art described above, and to press a sheet roll against a holding member even if its winding diameter changes by urging a pressing member to prevent the recording sheet from being skewed. It is an object of the present invention to provide a curl correction device capable of appropriately correcting the curl of a recording sheet using a curl correction member provided on a part of a pressing member, and a recording device having the curl correction device.

<Means for Solving the Problems> Typical means for solving the above-mentioned problems of the prior art and applied to the embodiments described below are as follows in the curl straightening device:
a holding member for holding a sheet roll having a recording sheet wound therein; a movable pressing member for pressing the sheet roll against the holding member; The sheet roll includes a curl correction member for correcting curls, and an urging means for urging the pressing member to press the sheet roll.

The recording device also includes the curl correction device, a sheet roll around which a recording sheet is wound, and a recording means for forming an image on the recording sheet pulled out from the sheet roll according to recording information. It has the following.

According to the above means, since the pressing member is urged by the urging means, even if the winding diameter changes, the pressing member moves and presses the sheet roll against the holding member. It is possible to prevent the recording sheet being pulled out from being skewed.

Further, since a curl correction member is provided in a part of the pressing member, the pressing member moves according to the winding diameter of the sheet roll, and the angle at which the recording sheet is wound around the curl correction member changes.
It is possible to appropriately correct curls that vary depending on the winding diameter.

Further, since the pressing member moves according to the winding diameter of the sheet roll, if a part of the pressing member is made visible from the outside, the remaining amount of the sheet roll can be detected.

Further, when the cover of the sheet roll is opened, the pressing member is released from the pressing member and retracted, thereby making it possible to easily take out and load the sheet roll.

Further, by forming one wall surface of the holding member, the pressing member can hold the sheet roll without requiring a particular space compared to a conventional holding member.

Further, when the pressing member presses the sheet roll toward the upstream side of the holding member in the recording sheet conveyance direction, and the bottom surface of the holding member is inclined in the direction in which the sheet roll rolls toward the upstream side in the recording sheet conveyance direction, The behavior of the sheet roll can be stabilized during conveyance of the recording sheet.

Further, when a stopper is provided in the movement range of the pressing member, it is possible to prevent the pressing member from interfering with other parts.

Furthermore, when the recording apparatus is equipped with the curl correction device, it is possible to prevent the recording sheet from curling, skewing, etc., so that the image quality can be maintained.

<Embodiment> An embodiment of a recording apparatus to which the present invention is applied will be described below with reference to the drawings.

FIG. 1 is an explanatory cross-sectional view showing a schematic configuration of a recording apparatus, and FIGS. 2 and 3 are explanatory views of its recording operation.

First, a schematic configuration of a recording apparatus to which the present invention is applied will be explained with reference to FIG.

Reference numeral 1 denotes a heat-sensitive recording sheet that develops color when heated, and a sheet roll 1b in which a long sheet is wound in a roll around an inner core 1a having a diameter of approximately 32 mm is held in a drop-in type roll holder 2, which is a holding member. ing. The bottom surface of the roll holder 2 is inclined by a small angle α so that the sheet roll 1b rolls toward the upstream side (to the right in the drawing) in the conveyance direction of the recording sheet 1.

The direction of pulling out the recording sheet 1 from the roll holder 2 (
A pressing member 3 for pressing the sheet roll 1b against the roll holder 2 is rotatably attached to the side surface (left side in the drawing) about a support shaft 4. A decurl shaft 5, which is a curl correcting member for correcting the curl of the recording sheet 1, is rotatably attached to the rotating tip of the pressing member 3.

Further, a tension coil spring 6 is connected to the support shaft 4 side of the pressing member 3, which is a biasing means for bringing the pressing member 3 into pressure contact with the sheet roll 1b.

This coil spring 6 is hooked on the claw portion 3a of the pressing member 3 and the boss 7 of the device main body, and biases the pressing member 3 clockwise around the support shaft 4, as shown in FIG. The pressing force F1 acts on the sheet roll 1b as shown in FIG.

Further, the recording sheet 1 pulled out from the sheet roll 1b is wound around the decurl shaft 5 at an angle θ in the opposite direction to the curl, and is squeezed to correct the curl. At this time, a resultant force F2 acts on the decal shaft 5 due to the tension of the recording sheet 1, as shown in FIG.

Therefore, the pressing force F is greater than the resultant force F2 (F,
>F), and the pressing member 3 is always maintained in a state in which the sheet roll 1b is pressed against the roll holder 2. In addition, the above pressing force F is the recording sheet 1
Since the sheet roll 1b rotates as the sheet is transported, the sheet roll 1b is set to a level that does not significantly affect the transport load.

Further, a low friction member 8 is attached to the contact surfaces of the roll holder 2 and the pressing member 3 that contact the sheet roll 1b.
The frictional force when the sheet roll 1b rotates and the recording sheet 1 is fed out is reduced, and since the pressing member 3 constitutes one wall surface of the roll holder 2, it takes up less space than conventional roll holders. does not require.

Further, since a pressing force F1 is applied to the sheet roll 1b by the pressing member 3, the sheet roll 1b is pressed to the upstream side of the roll holder 2 in the sheet conveyance direction, and the bottom surface of the roll holder 2 is pressed against the sheet roll 1b. Since it is tilted by a small angle α toward the upstream side in the conveyance direction of the recording sheet 1, the sheet roll lb can be stably held at one end of the roll holder 2 (on the right side in the drawing). Therefore,
It is possible to prevent the recording sheet 1 pulled out from the sheet roll 1b from being skewed.

The recording sheet 1 pulled out from the sheet roll 1b is decurled by a decurling shaft 5, and then an image is recorded by a recording head 9, which is recording means, according to recording information. The recording head 9 has heating elements arranged in a line that individually generate heat when energized according to recording information.
It is configured to come into pressure contact with the surface of the platen roller 10. The platen roller 10 is made of a member having a high friction coefficient, such as hard rubber, molded into a roller shape, and is configured to be driven by a drive source (not shown).

Therefore, an image is recorded on the recording sheet 1 by rotating the platen roller 10 in the direction of the arrow to convey the recording sheet 1, and in synchronization with this, the heating element of the recording head 9 generates heat according to the image signal. It is something that will be done.

The recorded recording sheet 1 is cut from the trailing edge of the image by a cutter 11, and is then cut by a pair of ejection rollers 12a, 12b.
The liquid is discharged to a discharge tray 13 provided outside the apparatus.

Next, the curl correction operation of the recording sheet 1 when the winding diameter of the sheet roll 1b changes will be explained with reference to FIGS. 2 and 3.

In FIG. 2, when the winding diameter φ of the sheet roll 1b is large, the pressing member 3 presses the sheet roll 1b while rotating counterclockwise against the elastic force of the coil spring 6. The angle θ1 of the wrapping of the recording sheet 1 around the decurl shaft 5 is set to be large (about 90 m in diameter and θ1 is preferably about 90°), and when the curl is weak, the curl correction force is also set to be small. In this case, in order to maintain the angle θ1 within the set angle range, the maximum movement range of the pressing member 3 includes a stopper 14 on the device main body side.
is provided.

Next, in FIG. 3, when the winding diameter φ of the sheet roll 1b is small, the pressing member 3 presses the sheet roll tb while rotating clockwise, and the recording sheet 1 is pressed against the decal shaft 5. The wrapping angle θ2 is set small (about φ40III11 and θ2 is 20°~
(preferably about 30°), and if the curl is strong, the curl straightening force is also set large. In this case, in order to maintain the angle θ2 of the winding at a set angle, a stopper 15 is provided protruding from the pressing member 3 to restrict the maximum movement range.

The stoppers 14, 15-4 restrict the movement range of the pressing member 3 and prevent interference between the pressing member 3 and other parts.

According to the above configuration, by pressing the sheet roll 1b against one end of the roll holder 2 by the pressing member 3, even if the winding diameter of the sheet roll 1b changes, the sheet roll 1b is simultaneously held integrally by the pressing member 3. By moving the decurl shaft 5, the angle at which the recording sheet 1 is wrapped changes appropriately, and curls can be corrected.

It is also possible to configure the apparatus so that when the upper cover 16 of the apparatus is opened in order to replace the sheet roll lb, the pressure of the pressing member 3 is released and the apparatus is retracted.

For example, as shown in FIG. 4, the claw portion 3a of the pressing member 3 and the upper cover 16 are connected by a wire 18 via a pulley 17. When the upper cover 16 is rotated about the fulcrum 16a to open the upper side of the device, the wire 18 is pulled upward, so the pressing member 3 rotates counterclockwise about the support shaft 4 and retreats. Therefore, the sheet roll 1b can be easily replaced, and since the platen roller 10 is attached to the upper cover 16, the conveyance path for the recording sheet 1 is also wide open, making it easy to set the recording sheet 1. Incidentally, the fulcrum 16a of the upper cover 16 can also be provided above the platen roller 10 or the like.

For example, as shown in FIG. 5, if an elongated hole 19 is bored in the exterior so that the position of the decal shaft 5 can be visually observed from the outside of the device, the remaining amount of the sheet roll 1b can be detected. can.

In the embodiment described above, the decurl shaft 5 is attached to the pressing member 3, but it is also possible to form a curl correction member by a part of the pressing member 3.

Further, the pressing surface of the sheet roll 1b of the pressing member 3 does not need to be flat, and may be a curved surface, a paraboloid, etc. so that the angle at which it is wound around the curl correction member is appropriate.

Further, the biasing means for the pressing member 3 is not limited to a tension coil spring, but may be a torsion coil spring, for example.

It may also be a compression coil spring, a torsion bar, or the like.

Furthermore, it goes without saying that the recording apparatus shown in this embodiment can be applied to various recording apparatuses such as printers and facsimile machines.

<Effects of the Invention> As described above, in the present invention, since the pressing member is urged by the urging means, even if the winding diameter changes, the pressing member moves and presses the sheet roll against the holding member. It is possible to prevent the recording sheet being pulled out from the sheet roll from being skewed.

Further, since a curl correction member is provided in a part of the pressing member, the pressing member moves according to the winding diameter of the sheet roll, and the angle at which the recording sheet is wound around the curl correction member changes.
It is possible to appropriately correct curls that vary depending on the winding diameter.

Further, since the pressing member moves according to the winding diameter of the sheet roll, if a part of the pressing member is made visible from the outside, the remaining amount of the sheet roll can be detected.

Further, when the cover of the sheet roll is opened, the pressure of the pressing member is released and the sheet roll is retracted, thereby making it easier to take out and load the sheet roll, thereby improving usability.

Further, by forming one wall surface of the holding member, the pressing member can hold the sheet roll without requiring a particular space compared to a conventional holding member.

Further, when the pressing member presses the sheet roll toward the upstream side of the holding member in the recording sheet conveyance direction, and the bottom surface of the holding member is inclined in the direction in which the sheet roll rolls toward the upstream side in the recording sheet conveyance direction, The behavior of the sheet roll can be stabilized during conveyance of the recording sheet.

Furthermore, when a stopper is provided in the movement range of the pressing member, it is possible to prevent the pressing member from interfering with other parts or the like.

Furthermore, when the above-mentioned curl correction device is installed in a recording apparatus, it is possible to prevent the recording sheet from curling 2 and skewing, so that the image quality can be maintained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram showing the schematic configuration of the recording apparatus, FIGS. 2 and 3 are explanatory diagrams of the curl correction operation of the recording sheet when the winding diameter of the sheet roll changes, and FIGS. 4 and 5 is an explanatory diagram of the other side, and FIGS. 6 to 8 are explanatory diagrams of a conventional example. 1 is a recording sheet, 1a is an inner core, 1b is a sheet roll, 2
is a roll holder, 3 is a pressing member, 3a is a claw part, 4 is a spindle, 5 is a decal shaft, 6 is a coil spring, 7 is a boss, 8 is a low friction member, 9 is a recording hand, 10 is a platen roller, 11 Reference numerals 12a and 12b are a pair of ejection rollers, 13 is an ejection tray, 14 and 15 are stoppers, 16 is an upper cover, 17 is a pulley, 18 is a wire, and 19 is a long piece.

Claims (8)

[Claims] (1) A holding member for holding a sheet roll having a recording sheet wound therein; a movable pressing member for pressing the sheet roll against the holding member; and a movable pressing member provided on a part of the pressing member. A curl straightening device comprising: a curl straightening member for straightening curls of a recording sheet; and a biasing means for biasing the pressing member to press the sheet roll. (2) The curl correction device according to claim 1, wherein the pressing member moves in accordance with a change in the winding diameter of the sheet roll, and the angle at which the recording sheet is wound around the curl correction member changes. (3) The curl straightening device according to claim 1, wherein the remaining amount of the sheet roll is detected by movement of a pressing member in accordance with a change in the winding diameter of the sheet roll. (4) The curl straightening device according to claim 1, wherein when a cover of the device main body is opened, the pressing member is released from the pressing member and retracted. (5) The curl straightening device according to claim (1), wherein the pressing member constitutes one wall surface of the holding member. (6) The bottom surface of the holding member has an inclination in the direction in which the sheet roll rolls upstream in the recording sheet conveying direction, and the pressing member presses the sheet roll upstream of the holding member in the recording sheet conveying direction. (1) The curl correction device described in (1). (7) The curl straightening device according to claim (1), further comprising a stopper provided in the movement range of the pressing member. (8) The curl straightening device according to any one of claims (1) to (7), a sheet roll having a recording sheet wound therein, and forming an image on the recording sheet pulled out from the sheet roll according to recording information. A recording device comprising: a recording means for recording; and a recording device.