JP2001019247A - Looseness removal device of roll type web - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove looseness of a web by reversely rotating machine-glazed paper which is a roll part of the web in simple constitution. SOLUTION: A first gear transmission mechanism 14 to support machine- glazed paper 2 of a web 3 by a set part 5 of a device main body 1 free to rotate, to clamp a head end side of the delivered web 3 by pinch rollers 17a, 17b and driving rollers 12a, 12b to deliver paper and to transmit motive power to the driving rollers 12a, 12b, a second gear transmission mechanism 34 to rotate the machine-glazed paper 2 and a reciprocally rotatable Y axis motor 13 are furnished. A working projection 60 to transmit motive power to the driving rollers 12a, 12b when the Y axis motor normally rotates and sideway projected to a side block 23a of a carriage 23 at the time of reverse rotation of the Y axis motor 13 prevents revolution of a working lever 49 in accordance with movement of it to approach a direction of the first gear transmission mechanism 14 and blocks transmission of motive power to the driving rollers 12a, 12b through a pair of planetary gears 42a, 42b in the middle of the first gear transmission mechanism 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing slack of a roll-shaped web such as a recording medium in an image forming apparatus such as a printer or a facsimile or a cutting apparatus such as a label sheet.

[0002]

2. Description of the Related Art For example, in Japanese Unexamined Utility Model Publication No. 5-95952, when a curl of a roll paper used as a recording medium in an image forming apparatus such as a facsimile is removed, a part of the roll paper drawn out is not loosened. In such a configuration, a round bar-shaped guide bar and a curling plate made of a spring plate provided with a nose portion having a protruding curved cross section are arranged in a paper (web) transporting path, and the roll paper is used. It is disclosed that curl is removed by sandwiching the unraveled paper in an S-shape, and at the same time, the looseness of the paper is regulated by an elastic film body near the nose.

[0003] On the other hand, the roll paper width size, roll length,
When judging the type of paper, etc., the data of the mark printed on the inner diameter of the center cylinder, which is the core of the roll paper, and the flanges on both the left and right sides of the roll paper, is detected by rotating the roll paper. There was a technology to determine by.

[0004]

However, if the paper is slackened in the transport path of the paper (web) at the initial stage when the roll paper is set, the above-described structure for restricting the slack of the roll paper causes the looseness of the paper. Since the paper portion is not actively wound (rewinded) in the direction of the roll paper, the roll paper portion remains stationary, and the sensor makes a false detection, such as determining that there is no roll paper. was there.

[0005] Such a problem is solved by a cutting device such as printing a predetermined area of a sheet unraveled from roll paper, cutting the sheet into a rectangular shape or the like so as to surround the printed portion, and creating a label or the like. Even so, it occurred.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problem. With a relatively simple structure, only a roll paper portion is fixed while a web on a work section side for image formation or the like is fixed. It is designed to be able to eliminate slack by reverse rotation.

[0007]

According to a first aspect of the present invention, there is provided a roll-shaped web slack removing apparatus according to the first aspect of the present invention, which is provided on one side of an apparatus main body having a working section for image forming or cutting. The roll portion of the web is rotatably supported, and a pinch roller and a drive roller for feeding paper, which are disposed near the working portion, hold the leading end side of the web fed from the roll portion, and the apparatus main body. A first gear transmission mechanism for transmitting power to the drive roller, a second gear transmission mechanism for transmitting power so as to rotate the roll portion, and a reversible rotatable mechanism for operating the two gear transmission mechanisms. One drive motor, and in the middle of the first gear transmission mechanism, when the drive motor rotates forward, power is transmitted to the drive roller, and when the drive motor rotates reversely,
In response to the movement of the working unit approaching the first gear transmission mechanism,
And a first transmission switching means for interrupting power transmission to the drive roller.

[0008] The invention described in claim 2 is the first invention.
In the device for removing the slack of a roll-shaped web according to the above,
The first transmission switching means includes a planetary arm for integrally rotating a pair of planetary gears in the first gear transmission, and an operating lever, and when the working unit approaches the first gear transmission, The power transmission to the drive roller is interrupted by contacting or forcibly rotating the operation lever.

According to a third aspect of the present invention, in the apparatus for removing slack of a roll-shaped web according to the first or second aspect, the drive gear of the drive motor is provided in the middle of the second gear transmission mechanism. A second transmission switching means is provided for interrupting power transmission during rotation and for reversely rotating the roll portion of the web when the drive motor rotates in the reverse direction.

[0010]

Next, embodiments of the present invention will be described.

FIG. 1 is a side view of a printing apparatus for tack paper, and FIG.
Is a plan view, FIG. 4 is a plan view of a carriage of the cutter holder,
FIG. 5 is a side view of the gear transmission mechanism in a state where the roll paper is unwound and the recording paper is advanced, and FIG. 6 is a side view of the gear transmission mechanism in a state where the roll paper is rewound.

As shown in FIGS. 8 to 10, the roll paper 2 applied to the present invention is obtained by applying an adhesive such as a pressure-sensitive adhesive to the back surface of a recording paper which can be printed on the front surface as a strip-shaped web 3. The pressure-sensitive adhesive layer is attached to the surface of a strip-shaped release paper, and is wound around a central cylindrical body 61 such as a paper tube. One or more long detection holes 62 (three in this embodiment are illustrated) are formed. Then, on the winding inner surface of the connecting piece 3a for winding the base end of the web 3 around the central cylindrical body 61, the width dimension, paper quality, roll winding length, etc. A discrimination mark 63, such as a black and white band, for discriminating the type of the roll paper 2 is attached by printing, labeling, or the like (see FIG. 10).

The recording paper that can be printed may be plain paper, glossy paper or synthetic resin film.

In the printing apparatus to which the present invention is applied, the roll paper 2 as a roll portion of the web 3 and a central cylindrical body 61 are provided on the left end portions of the pair of lower frames 4 and 4 of the apparatus main body 1 in FIG. A set portion 5 is provided to be rotatably supported. Then, as shown in FIGS. 8 and 9, when the roll paper 2 is set in the setting section 5, a pair of roll holders 57 and 64 holding both side ends of the roll paper 2 are fitted inside the central cylindrical body 61. Then, the engaging claw 6 of the other roll holder is inserted into the engaging hole 65 of the one roll holder 57.
6 are elastically engaged. The other roll holder 64
A watermark hole 67 is formed at a position corresponding to the detection hole 62 in the inner diameter portion of.

The inner surfaces of the flange portions 57a, 64a of the pair of roll holders 57, 64 are engaged with engaging grooves 61a, 61a formed at both ends of the central cylindrical body 61 so as to be relative to each other. Engagement protrusions 68 for preventing rotation are provided.

As shown in FIGS. 8 and 9, the set portion 5 has a substantially U-shaped upward shape for rotatably supporting a pair of roll holders 57 and 64 holding the roll paper 2. Receiving portions 69a and 69b are provided, and one of the receiving portions 69b is provided with a sensor holder 70 that rotates so that the sensor portion 70a faces the position of the watermark hole 67 when the roll holder 64 is dropped into the receiving portion 69b. Is provided. When the sensor holder 70 is not pressed downward by the roll holder 64, the sensor holder 70 is twisted at the shaft 71 so as to rotate upward to a position outside the receiving portion 69 b (outside the range in which the roll holder 64 moves up and down). Respring 72
It is energized by.

Accordingly, when the roll paper 2 set in the setting section 5 rotates, the discrimination mark 63 can be read by the light reflection type sensor section 70a through the watermark hole 67 and the detection hole 62. The type of the roll paper 2 is discriminated and stored by an electronic controller (not shown), which is useful for controlling operations such as printing conditions and cutting width.

In FIG. 1, a roller-shaped platen 6 is disposed in the middle of the apparatus main body 1 in the longitudinal direction, and the web 3 unwound from the roll paper 2 at the setting section 5 is placed on the upper surface of the platen 6. The cutting part 1 in the right end direction of FIG.
0. Arms 7, 7 mounted on the upper frames 16, 16 so as to be vertically rotatable.
A thermal head 9 provided on the lower surface of a frame 8 connecting the leading ends of the frames forms a printing section for forming an image such as printing by pressing and contacting the web 3 on the platen 6.

As shown in FIGS. 1 and 2, a pair of front and rear drive rollers 12a for transporting the web 3 across a table 11 which is long in the X-axis direction and short in the Y-axis direction (transport direction), as shown in FIGS. , 12b are arranged, and both drive rollers 12a, 12b are rotationally driven in the same direction from a Y-axis motor 13 which can be rotated forward and backward via a first gear transmission mechanism 14, which will be described in detail later.

Pinch rollers 17a, 17b facing the drive rollers 12a, 12b from above are interposed between upper frames 16, 16 which rotate vertically via pivots 15 at the left ends of the pair of lower frames 4, 4. When the upper frames 16, 16 are turned downward with respect to the lower frames 4, 4 and closed, the pinch rollers 17 a, 1 are closed.
7b respectively presses the drive rollers 12a and 12b so that the web 3 can be conveyed therebetween.

In this embodiment, the printing unit is a web 3
Although the horizontal thermal head 9 is used over the entire width of the ink jet head, as another embodiment, an ink jet type print head or a print head of a type for printing with a dot pin or a thermal head via an ink ribbon may be used. .

A carriage 23 as a working unit movable in the width direction (X-axis direction) of the web 3 includes a main guide shaft 18a, such as a round shaft, mounted between the pair of upper frames 16, 16, and an auxiliary guide. It is slidably mounted on the shaft 18b. Then, one position of a timing belt 21 wound around a driving pulley 19 and a driven pulley 20 disposed on each inner surface of the pair of upper frames 16, 16 is fixed to the carriage 23, and a forward / reverse rotatable step motor is provided. X such as
The timing belt 21 is driven to rotate in the X direction from the shaft motor 22 via the X-axis
Is selectively moved in the X-axis direction.

An elevating block 25 is mounted on the carriage 23 so as to be movable up and down between the side block 23a, and a substantially cylindrical cutter holder 26 is fixed to the elevating block 25. A horizontally long rotating arm 28 mounted between the pair of upper frames 16, 16.
The free-end side which rotates vertically is fitted in the lateral fitting groove 25a of the elevating block 25, and is rotated by a Z-axis motor 27 such as a step motor or the like, which can be rotated forward and backward, via a holder height adjusting mechanism 29, which is not described in detail. The free end side of the rotating arm 28 is moved up and down to move the cutter holder 26 to the table 1.
1 is configured to be able to be raised and lowered with respect to the upper surface.

The cutter blade 26 has a cutting blade 30 at its lower end.
The cutting blade 30 is rotatably supported about a vertical axis and is supported so as to be able to move up and down. A half-cut position where the amount projecting from the lower surface of the cutter holder 26 cuts only the recording paper in the web 3 and does not cut the release paper, and a full cut position where the recording paper and the release paper are pierced to completely cut the web; The height position of the cutting blade 30 is adjusted to a position where the cutting edge of the cutting blade 30 does not touch the surface of the recording paper so that the cutting edge protrudes.

A first gear for rotating both drive rollers 12a and 12b in the same direction by the operation of a Y-axis motor 13 such as a step motor capable of rotating forward and backward is provided on the outside of the one lower frame 4. A transmission mechanism 14 and a second gear transmission mechanism 34 for executing rewinding of the roll paper 2 are arranged. 1 and 4 to 7 show a first embodiment of the present invention, in which a first gear transmission mechanism 14 is a small gear that rotates integrally with a first gear 36 from a pinion 35 fixed to an output shaft of a Y-axis motor 13. Power is transmitted to a platen gear 37 that rotates integrally with the platen 6 via a gear 36a, and a sun gear 40 is rotated from the pinion 35 via a second gear 38 and a third gear 39. ing. Two planetary gears 42a and 42b are mounted on a planetary arm 41 pivotally supported on a support shaft of the sun gear 40, and the two planetary gears 42a and 42b are connected to the sun gear 40. Are engaged.

When the Y-axis motor 13 rotates forward (when the pinion 35 rotates clockwise as shown in FIG. 5), the sun gear 40 rotates counterclockwise, and the two planetary gears 42a, 42 meshing therewith. 42b revolves counterclockwise via the planetary arm 41 while rotating clockwise, and the revolution stops at a position where one planetary gear 42a meshes with the fourth gear 43. The pair of drive rollers 12a,
It is configured to rotate the two fifth gears 45, 45 with respect to 12b in the same direction.

Further, the first gear transmission mechanism 14 includes:
First transmission switching means 46 utilizing the planetary gears 42a and 42b and the planetary arm 41 is provided. That is, as shown in FIG.
Is fitted in a loose fitting hole 50 of an operating lever 49 rotatably supported via a shaft 48 of the one lower frame 4. Therefore, as described above, when the Y-axis motor 13 rotates forward, the tip (upper end) of the operating lever 49 rotates clockwise.

The second gear transmission mechanism 34 operates only when the Y-axis motor 13 rotates in the reverse direction (see FIGS. 6 and 7; the pinion 35 rotates counterclockwise). 6 rotates counterclockwise, the first gear 36 rotates clockwise, and the platen 6 rotates counterclockwise, as shown in FIG. Then, a planetary gear 52 rotatably supported by a third arm 51 rotatable around a support shaft of the first gear 36 as a second transmission switching means.
Is a small gear 36a that rotates integrally with the first gear 36.
, The third gear 51 rotates clockwise while the planetary gear 52 rotates counterclockwise, and the planetary gear 52 is prevented from revolving at a position where the planetary gear 52 meshes with the sixth gear 53. A seventh gear 54 coaxial with the sixth gear 53
A slip clutch 55 that slips when a torque equal to or more than a predetermined value acts is interposed. The seventh gear 54 meshes with a roll gear 58 on the outer circumference of a roll holder 57 attached to one side of the roll paper 2 via an intermediate gear 56 via an intermediate gear 56 to transmit power, and the roll paper 2 rotates clockwise in FIG. ,
The web 3 is rewound (rewinded).

In this case, since the sun gear 40 rotates clockwise in the first gear transmission mechanism 14, the other of the two planetary gears 42a and 42b that mesh with the sun gear 40 and revolve clockwise while rotating. Is the fourth planetary gear 42b
The revolution stops at the position where the gear 43 meshes. Then, the small gear 4 that rotates integrally and coaxially with the fourth gear 43
4, the two fifth gears 45, 45 for the pair of drive rollers 12a, 12b are rotated in the same direction (counterclockwise).

Therefore, at the cutting section 10, the web 3 sandwiched between the driving rollers 12a and 12b and the pinch rollers 17a and 17b is also reversely conveyed leftward in FIG. Also, when the winding diameter of the roll paper 2 increases,
Although the winding amount per rotation gradually increases, the rotation speed of the roll paper 2 can be gradually reduced while applying a predetermined tension by the operation of the slip clutch 55.

As described above, when the pinion 35 rotates clockwise (when the web 3 is conveyed rightward as shown in FIG. 5), the small gear 36a which rotates integrally with the first gear 36 is provided. The third arm 51 rotates in the counterclockwise direction.
Rotates counterclockwise, and the planetary gear 52 and the sixth gear 5
3 is released, and the portion of the roll paper 2 is in a free state.

When the roll paper 2 is rewound to loosen the web 3 in the middle, as shown by the solid line in FIG. When approaching the lower frame 4, the operation protrusion 60 laterally protruding from the side block 23 a abuts on the left side of the upper end of the operation lever 49 which is about to rotate counterclockwise. To a neutral position. Thereby, the movement of the planetary arm 41 engaged with the operating lever 49 is regulated, and the pair of planetary gears 42 attached to both ends of the planetary arm 41 are controlled.
Both a and b are held at neutral positions where they do not mesh with the fourth gear 43.

Therefore, the pair of front and rear drive rollers 12
The transmission of the rotational force to the driving rollers 12a and 12b is stopped, and the rotation of the driving rollers 12a and 12b is stopped.
Since the portion of the web 3 sandwiched between the pinch rollers 2a and 12b and the pinch rollers 17a and 17b is not conveyed in any of the front and rear directions and is constrained, The slack of the web 3 of the roll paper 2 can be removed.

Next, the preparation operation for discriminating the type of the roll paper 2 will be described.
When set in the pair of upper frames 16, 16
Is turned upward to open the setting section 5, and the front end of the web 3 fed (pulled out) from the roll paper 2 set in the setting section 5 is moved forward and backward in the cutting section 10 as a working section. The upper frame 16 is closed so as to be located to the right of the drive rollers 12a and 12b. Then, the leading end of the web 3 can be detected by the leading end detection sensor 73 disposed in the right direction (downstream of the conveyance) of the drive rollers 12a and 12b.

During this operation, if there is a slack between the setting section 5 and the end of the web 3, the drive roller 12
Even if the web 3 sandwiched between the a and 12b and the pinch rollers 17a and 17b is driven to rotate in the feeding direction (forward direction) as shown in FIG. 5, the roll paper 2 rotates until the slack portion is in a tension state. Therefore, the discrimination mark 63 attached to the roll paper 2 cannot be discriminated by the sensor unit 70a provided in the setting unit 5. In such a state, first, the Y-axis motor 13 is slightly rotated forward to
9 is rotated clockwise, and the operating lever 49 is securely moved in the extending direction so that the operating lever 49 does not come into contact with the operating projection 60 protruding from the hole formed in the lower frame 4 as the carriage 23 moves. Keep it tilted. Next, as shown in FIG. 4, the carriage 23 is moved along the X-axis direction to approach or contact one of the lower frames 4, and the operation projection 60 projecting from the side block 23a is moved downward. It faces one side of the operating lever 49 from a hole formed in the frame 4 to restrict the operating lever 49 from tilting and rotating in the retreating operation direction (see FIG. 7).

In this state, when the Y-axis motor 13 is once rotated in the reverse direction for an appropriate period of time, the roll paper 2 in the setting section 5 rotates in the reverse direction (winding operation), while the front end of the web 3 is moved to the pinch rollers 17a, 17b. The rotation of the portions of the drive rollers 12a and 12b sandwiched by the stop is stopped, so that the slack of the web 3 is removed as described above. When tension acts on the web 3, the roll paper 2 does not rotate even if the third gear transmission mechanism 34 rotates due to the function of the slip clutch 55. Thus, the fact that the web 3 is loosened and the roll paper 2 does not rotate can be detected from the fact that the reading signal of the sensor unit 70a does not change.

In this state, the Y-axis motor 13 is stopped, and then the carriage 23 is moved away from the lower frame 4 to release the restriction on the operation lever 49, and then the Y-axis motor 13 is rotated forward. Thus, the discrimination mark 63 may be read by the sensor unit 70a while the forward operation is started to move the distal end side of the web 3 to the right in FIG.

FIGS. 11 and 12 show a first transmission switching means 46 'as a second embodiment. FIG. 11 shows an operation state when the web 3 advances, and FIG. 12 shows an operation state when slack is removed. . The configuration of the first transmission switching means 46 'is such that a first gear transmission mechanism 14 for rotating both drive rollers 12a and 12b in the same direction by the operation of a Y-axis motor 13 such as a step motor capable of forward and reverse rotation. Planetary arm 4 pivotally supported on a support shaft of a sun gear 40 which is an intermediate part of
1 'is provided with one planetary gear 42a',
The planet gears 42a 'mesh with the sun gear 40. On the other hand, the intermediate lever 75 rotates about the support shaft of the fourth gear 43, and a guide groove into which one end of the support shaft 76 of the planetary gear 42a 'is fitted at one end of the intermediate lever 75. 77 is formed by drilling. This guide groove 77 is
The planetary gear 42a 'includes the planetary gear 42a' and the fourth gear 43.
, And at least the planetary gear 42a 'and the fourth gear 4
3 and an open groove 77a from which the engagement with the opening 3 is released.

An engaging pin 78 protruding from the other end of the intermediate lever 75 is provided with a loose fitting hole 8 of an operating lever 79 rotatably supported via the shaft 48 of the driving roller 12a.
It is fitted in 0. Further, the intermediate lever 75 is
By the urging spring 81, the support shaft 76 of the planetary gear 42a '
Is biased in a direction to fit into the regulating groove 77b.

Therefore, as described above, when the Y-axis motor 13 rotates forward, as shown in FIG.
5 rotates clockwise, the sun gear 40 rotates counterclockwise via the second gear 38 and the third gear 39, and the planetary gear 42a 'meshing therewith rotates clockwise, and the fourth gear 4 rotates.
3 is engaged with the small gear 44 which rotates coaxially and integrally with the driving roller 12a.
The fifth fifth gears 45 are rotated in the same direction.

In order to remove the slack of the web 3, as shown in FIG. 4, the carriage 23 is moved in advance in the X-axis direction so as to approach or abut on one lower frame 4, and the side block 23a Operating projection 60 projecting from
Is projected from a hole formed in the lower frame 4, and the upper end 79 a of the operating lever 79 is pushed downward (clockwise in FIG. 12) to rotate the operating lever 79 clockwise in FIG. 12. Then, the engagement pin 78 fitted in the loose fitting hole 80 moves to the left in FIG. With this movement,
Since the intermediate lever 75 is rotated counterclockwise against the spring force of the biasing spring 81, the support shaft 7 of the planetary gear 42a 'is
6 moves to the upper left end of the lower open groove 77a of the guide groove 77.

When the Y-axis motor 13 is rotated in the reverse direction in this state, as shown in FIG. 12, the pinion 35 rotates counterclockwise, and the sun gear 40 is rotated via the second gear 38 and the third gear 39. Planetary gear 4 that rotates clockwise and meshes with it
2a 'rotates counterclockwise and revolves clockwise via the planetary arm 41', so that the support shaft 76 is open groove 77a.
To the lower left end of the second gear 43 to maintain the position where the engagement with the fourth gear 43 is released. As a result, the leading end side of the web 3 is
12b and the pinch rollers 17a and 17b, while the set portion 5 reversely rotates the roll paper 2 in the winding direction via the second gear transmission mechanism 34, so that the web 3 Can be removed. Thereafter, by moving the carriage 23 away from the lower frame 4, the urging spring 81 moves the support shaft 7.
6 can be returned to the position of the restriction groove 77b.

[0043]

As described in detail above, the apparatus for removing slack in a roll-shaped web according to the first aspect of the present invention is provided with a web on one side of an apparatus body provided with a working section for image formation or cutting. The roll portion is rotatably supported, and a pinch roller and a driving roller for feeding paper disposed near the working portion hold the leading end side of the web fed from the roll portion, while the apparatus body includes: A first gear transmission mechanism for transmitting power to the drive roller, a second gear transmission mechanism for transmitting power so as to rotate the roll portion, and one drive capable of normal and reverse rotation for operating the two gear transmission mechanisms; A motor for transmitting power to the drive roller when the drive motor rotates forward, and a work unit for rotating the drive motor when the drive motor rotates reversely.
A first transmission switching means for interrupting power transmission to the drive roller in accordance with a movement approaching the gear transmission mechanism is provided, so that one drive motor is switched between forward rotation and reverse rotation. Unwinding the web while rotating the roll part forward, and transporting the tip in the direction of the working part;
The web that has been once unwound can be moved in the simultaneous rewinding direction while rotating the roll portion in the reverse direction, and the first transmission switching means provided in the middle of the first gear transmission mechanism is configured such that the working portion is the first transmission switching device. Actuating in response to the movement approaching the gear transmission mechanism, the second gear transmission mechanism reversely rotates only the roll section while preventing the first gear transmission mechanism from moving in the reverse rotation direction on the web tip side, The slack of the web in the middle can be easily removed.

Further, the invention described in claim 2 is the same as that in claim 1
In the device for removing the slack of a roll-shaped web according to the above,
The first transmission switching means includes a planetary arm for integrally rotating a pair of planetary gears in the first gear transmission, and an operating lever, and when the working unit approaches the first gear transmission, The power transmission to the drive roller is interrupted by contacting or forcibly rotating the operation lever.

According to this configuration, the planetary arm for integrally rotating the pair of planetary gears in the first gear transmission mechanism is used, and the operating lever connected thereto serves as the first transmission switching means. There is an effect that the configuration becomes very simple.

According to a third aspect of the present invention, in the apparatus for removing slack of a roll-shaped web according to the first or second aspect, the drive gear of the drive motor is provided in the middle of the second gear transmission mechanism. A second transmission switching means for interrupting power transmission during rotation and reversely rotating the roll portion of the web at the time of reverse rotation of the drive motor is provided, so that the web and the roll portion are integrated in opposite directions. It is possible to perform the movement (reverse rotation) and also perform the reverse rotation of only the roll part when removing the slack of the web.

[Brief description of the drawings]

FIG. 1 is an overall side view of a label printing apparatus.

FIG. 2 is an overall plan view of the label printing apparatus.

FIG. 3 is a side view of a cutting section.

FIG. 4 is a plan view of a carriage as a working unit.

FIG. 5 is a side view showing an operation state of the first gear transmission mechanism and the second gear transmission mechanism when the web moves in the forward direction.

FIG. 6 is a side view showing an operation state of the first gear transmission mechanism and the second gear transmission mechanism when the web is moved in the backward direction.

FIG. 7 is a side view showing an operation state of a first gear transmission mechanism and a second gear transmission mechanism during a web slack removal operation.

FIG. 8 is a partially cutaway sectional view of a setting portion of a roll portion (roll paper) of a web.

FIG. 9 is a view taken on line IX-IX of FIG. 8;

FIG. 10 is a perspective view showing a roll paper determination mark.

FIG. 11 is a side view showing the operation of the first transmission switching means at the time of web forward movement in the second embodiment.

FIG. 12 is a side view at the time of a web slack removal operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Roll paper as a roll part 3 Web 4 Lower frame 5 Set part 13 Y-axis motor 14 1st gear transmission mechanism 12a, 12b Drive roller 17a, 17b Pinch roller 23 Carriage 23a Side block 34 2nd gear transmission mechanism 35 pinion 36 first gear 38 second gear 39 third gear 40 sun gear 41 planetary arm 42a, 42b planetary gear 43 fourth gear 43a small gear 46 first transmission switching means 47 engaging pin 49 operating lever 51 third arm 52 Planetary gear 60 operating projection 73 tip sensor

Claims (3)

[Claims] 1. A web roll portion is rotatably supported on one side of an apparatus main body provided with a work section for image formation or cutting, and a pinch roller disposed near the work section and a drive for paper feeding. While holding the leading end side of the web unwound from the roll portion with a roller, the apparatus body includes:
A first gear transmission mechanism for transmitting power to the drive roller, a second gear transmission mechanism for transmitting power so as to rotate the roll portion, and one drive capable of normal and reverse rotation for operating the two gear transmission mechanisms; A motor is provided. In the middle of the first gear transmission mechanism, when the drive motor rotates forward, power is transmitted to the drive roller, and when the drive motor rotates reversely, the working unit is connected to the first gear transmission mechanism. An apparatus for removing slack in a roll-shaped web, comprising a first transmission switching means for interrupting power transmission to the drive roller in response to the approaching movement. 2. The first transmission switching means includes a planetary arm for integrally rotating a pair of planetary gears in a first gear transmission mechanism, and an operating lever, and a working unit includes a first gear transmission. 2. The apparatus for removing slack from a roll-shaped web according to claim 1, wherein the power transmission to the drive roller is interrupted by contacting or forcibly rotating the operation lever when approaching the mechanism. . 3. A second transmission for interrupting power transmission during forward rotation of the drive motor and reversely rotating the roll portion of the web during reverse rotation of the drive motor in the middle of the second gear transmission mechanism. The apparatus for removing slack of a roll-shaped web according to claim 1 or 2, further comprising switching means.