JP2011152670A - Recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording apparatus which can suppress the generation of slack of a roll paper and can maintain a transfer accuracy of the roll paper, even if the roll paper rotates in a direction to unwind because of an operator's inadvertent contact with the roll paper. <P>SOLUTION: The recording apparatus 160 records an image on the transferred roll paper 111. A transfer driving means 600 is provided which has a braking force variable device 116 (316) capable of winding off and winding up the roll paper from a roll paper spool 112 and capable of varying a braking force of the roll paper being wound off and wound up. A control means 500 is provided which controls the braking force variable device to change the braking force of the roll paper when the roll paper is transferred and recorded and when the roll paper is wound up. The control means controls the braking force so that the braking force of the roll paper at the time of non operation when the roll paper is not transferred becomes larger than the braking force of the roll paper at the time of transfer when the roll paper is transferred. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording apparatus that performs recording on roll paper, and more particularly to a recording apparatus that includes a mechanism for preventing sagging of roll paper.

  2. Description of the Related Art Devices having functions such as a printer, a facsimile machine, and a copying machine are used as a recording device that records an image with a recording head based on image information on a recording medium conveyed through a recording unit. As the recording medium, roll paper which is continuous paper is used in addition to cut paper having a predetermined size. In a recording apparatus using roll paper, recording is performed on the roll paper by a recording head based on image information while the unrolled roll paper is conveyed by a conveyance roller. At this time, the roll paper is set so as to be rotatable (unwound) with respect to the recording apparatus while being wound around the spool shaft.

  With respect to such a recording apparatus using roll paper, Patent Document 1 discloses a configuration in which a torque limiter for applying a braking force to the roll paper is attached to the spool shaft and a constant back tension is applied to the roll paper to be conveyed. Is disclosed. In Patent Document 1, the back tension applied by the torque limiter is uniquely determined. Therefore, when recording on roll paper of another size or different type, it is necessary to replace the roll paper spool with another torque limiter suitable for the roll paper, and the work of replacing and storing the roll paper spool is complicated.

  Therefore, as a technique for dealing with this, Patent Document 2 discloses a printer having a mechanism for automatically switching to an appropriate back tension (braking force) according to the type and size of roll paper to be used. In this printer, it is possible to switch between a light back tension and a heavy back tension, and in a normal printing operation, a predetermined amount is recorded in a state in which a conveyance force and a pinch roller are nipped to ensure a conveyance force. Yes. At that time, the roll paper is controlled so as to apply a light back tension within a range that does not cause wrinkles or skews and does not hinder the conveying force of the conveying roller. By doing so, the quality of the recorded image can be maintained without causing wrinkles, skewing, feed unevenness, etc. in the recording medium. However, when recording is performed on roll paper that is stiff and easy to unwind, the roll paper may be gradually unwound due to a slight vibration of the printer or a conveyance operation during recording. In order to prevent such unraveling, a setting is made such that a heavy back tension is applied to some roll papers within a range that does not affect the conveyance accuracy.

JP 2005-096987 A JP 2007-290866 A

  However, in both the light back tension and the heavy back tension settings, the value is not enough for unwinding of various types of roll paper. It sometimes occurred. In addition, if a roll paper with a strong stiffness with force applied in the unwinding direction is set, the roll paper will repeatedly expand and contract due to temperature and humidity fluctuations over time, and the roll paper will increase in number. there were. When recording is started in this unwound state, the loosening state is gradually eliminated as the roll paper is conveyed. In this case, since the back tension is not applied while recording in the unwound state, the carry amount becomes larger than the original, and there may be a non-image area (white stripe) at the joint of the image.

  The present invention has been made in view of such technical problems. The object of the present invention is to suppress the occurrence of sagging of the roll paper and maintain the roll paper transport accuracy even if the operator carelessly contacts the roll paper and tries to rotate in the direction in which the roll paper can be unwound. It is to provide a recording device.

  The present invention relates to a recording apparatus that records an image on a conveyed roll paper by a recording head, and can roll out and wind up the roll paper from a roll paper spool. Conveyance drive means having a variable braking force variable device, and control means for controlling the braking force variable device so as to change the braking force of the roll paper during the conveyance / recording and winding of the roll paper. The roll paper is controlled so that the braking force of the roll paper during non-operation when the roll paper is not transported is larger than the braking force of the roll paper during the transport of transporting the roll paper.

  According to the present invention, by variably controlling the braking force of the roll paper spool, the occurrence of sagging of the roll paper can be suppressed even if the operator inadvertently touches the roll paper and tries to rotate the roll paper in the unwinding direction. And a recording apparatus capable of maintaining the conveyance accuracy of the roll paper is provided.

1 is a perspective view of a recording apparatus according to an embodiment. 1 is a perspective view of an internal configuration of a recording apparatus according to an embodiment. 1 is a longitudinal sectional view of an internal configuration of a recording apparatus according to an embodiment. Plan view of drive path from transport motor to transport roller and roll paper spool Explanatory drawing which shows the structure of the braking force variable apparatus which concerns on 1st Embodiment. FIG. 5 is an explanatory diagram showing the state of the braking variable device in FIG. 5 when a weak braking force is generated when conveying / recording or when there is no roll paper. Explanatory drawing which shows the state of the braking variable apparatus of FIG. 5 when winding up, applying a weak braking force to roll paper FIG. 5 is an explanatory diagram showing a state of the braking variable device in FIG. 5 when a strong braking force is applied to the roll paper during conveyance / recording or when the roll paper is set and inactive. Explanatory drawing which shows the state of the braking variable apparatus of FIG. 5 when winding up, providing a strong braking force to roll paper The table | surface which shows the relationship between the ON / OFF state of each actuator and the magnitude | size of braking force in the braking force variable apparatus of FIG. Explanatory drawing which shows the structure of the braking force variable apparatus which concerns on 2nd Embodiment. 11 is an explanatory diagram showing the state of the braking variable device in FIG. 11 when a strong braking force is generated during conveyance / recording or when the roll paper set is not operating. The table | surface which shows the relationship between the ON / OFF state of each actuator and the magnitude | size of braking force in the braking force variable apparatus of FIG.

Embodiments of the present invention will be specifically described below with reference to the drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings.
[First Embodiment]
FIG. 1 is a perspective view of a recording apparatus according to an embodiment. FIG. 2 is a perspective view of the internal configuration of the recording apparatus according to the embodiment. FIG. 3 is a longitudinal sectional view of the internal configuration of the recording apparatus according to the embodiment. In this embodiment, the case where the recording apparatus is an ink jet recording apparatus that performs recording by discharging ink from a recording head to a recording medium based on image information is illustrated. The recording apparatus according to the present embodiment performs recording using at least roll paper that is continuous paper, regardless of whether or not recording is possible on cut paper. As the recording medium, various materials such as paper and plastic sheets can be used, and the material is not limited.

  The illustrated recording apparatus 160 is an ink jet recording apparatus capable of recording on roll paper (rolled continuous paper), and can record up to a relatively large size such as JIS standard A1 size or JIS standard B1 size. The recording apparatus (the apparatus main body) 160 includes a paper feeding unit 110 on which roll paper 111 as a recording medium is set, a conveyance / recording unit 120 that conveys and records the roll paper, and discharges the recorded roll paper And a paper discharge unit 130. The recording device 160 is detachably fixed on the stand 140. The paper feeding unit 110 is disposed in front of the lower part of the recording apparatus (apparatus main body) 160. Inside the paper supply unit 110, a roll paper spool 112 in which the roll paper 111 is set in advance so as to be unwindable is housed. The roll paper spool 112 includes a fixed flange 113, a movable flange 114, and a spool shaft 115. The fixed flange 113 is fixed to one end of the spool shaft 115, and the position of the movable flange 114 can be adjusted along the spool shaft 115. When the roll paper 11 is set on the roll paper spool 112, the movable flange is moved in accordance with the paper width of the roll paper 111 to sandwich the both ends, thereby positioning the roll paper in the width direction. The roll paper 111 set on the roll paper spool 112 is rotatably supported with respect to the apparatus main body 160 and has a predetermined braking force when unwinding and rewinding by the braking force variable device 116 connected to the spool shaft 115. (Back tension) can be applied.

  The paper feeding unit 110 is disposed in front of the recording device 160. The roll paper 111 unwound from the paper supply roll spool 112 of the paper supply unit makes a U-turn from the lower front and is conveyed substantially horizontally through the conveyance / recording unit 120 and the paper discharge unit 130 arranged at the top. The An image is recorded by the recording head 121 on the roll paper conveyed on the platen 128 of the conveyance / recording unit and the paper discharge guide 131 of the paper discharge unit. The roll paper that has been recorded is cut on the rear side of the recorded image by a cutter (not shown) disposed on the upstream side of conveyance of the paper discharge guide 131, and the separated image recording unit (for one page) is placed on the stand unit 140. The sheet is discharged to the mounted sheet receiving portion 150.

  The main body 160 of the recording apparatus is provided with a control unit 500 including a controller including a CPU, a memory, an I / O circuit, and the like. The control means 500 controls the operation of the drive motor and various devices according to a control program stored in advance in the internal memory. Thus, the conveyance / recording operation of the roll paper 111 as a recording medium is controlled, and the drive of the recording head 121 is controlled based on the image data, thereby recording an image on the roll paper. Further, the control means 500 controls the operation of the braking force variable devices 116 and 316 and the conveyance driving means 600 including the same as described later. Further, the control unit 500 controls the overall operation and timing of other recording apparatuses.

  The transport / recording unit 120 includes a carriage 122 on which the recording head 121 is mounted, a flat cable 123 that electrically connects the recording head 121 to the control unit 500, and an ink tube 124 that connects the recording head 121 to the ink tank 125. , Is provided. The control means 500 connected to the recording head 121 is built in the apparatus main body 160. The carriage 122 is supported so as to be able to reciprocate in the main scanning direction (direction intersecting the transport direction) along a guide shaft 127 installed in the apparatus main body. Further, the conveyance / recording unit 120 is disposed to face a conveyance roller 129 that conveys the roll paper 111, a driven roller (not shown) that can be pressed against and separated from the conveyance roller, and a recording head 121 on the carriage 122. Platen 128. The recording head 121 includes an ejection unit that ejects ink of each color such as black, yellow, cyan, and magenta. An openable and closable upper cover 125 is provided on the upper surface of the conveyance / recording unit 120 of the recording apparatus 160 so that the recording head 121 and the carriage 122 can be accessed from the outside.

  Drive is transmitted from a carriage drive (not shown) to a carriage belt (not shown) connected to the carriage 122, so that the carriage 122 is guided by the rail 127 and reciprocates. The flat cable 123 has one end connected to the connector of the control unit and the other end connected to the connector of the recording head 121, and sends a recording signal from the control unit to the recording head 121. The ink tubes 124 for each color ink have one end connected to the corresponding ink tank 125 and the other end connected to each color ink discharge portion of the corresponding recording head 121. The upper cover 126 is rotatably supported at the upper part, and can be opened and closed by the user pushing up and down with the lower part. The transport roller 129 is formed as a single long roller, and is pivotally supported by the frame at both ends via bearings. Further, the transport roller 129 can be rotated in both forward and reverse directions via a pulley, a belt, and the like by forward / reverse driving of the transport motor 231 (FIG. 4). The driven roller pressed against the transport roller 129 is composed of a plurality of short roller rollers that are rotatably supported by a plurality of driven roller support members arranged in parallel in the axial direction.

  The platen 128 is formed in a rectangular flat plate shape having a length larger than the maximum recordable paper width, and is disposed on the downstream side of the conveyance roller 129. The paper discharge unit 130 includes a paper discharge guide 131 that forms part of the transport path in the sub-scanning direction, and a paper discharge roller (not shown) that suppresses the reverse warping of the roll paper. The stand unit 140 includes two support stays 142 each having a moving caster 141, and a reinforcement stay 143 that is spanned between the support stays 142. The recording apparatus (its main body) 160 is fixed on the support stay 142 with screws or the like while being placed on the upper portion of the support stay 142. Left and right tank storage portions 161 and 162 for storing and holding the left and right ink tanks 125 and 125 are provided at both side ends of the back surface of the apparatus main body 160. The upper surfaces of the tank storage portions 161 and 162 are covered with tank covers 163 and 164, respectively. It has been broken. Further, an operation panel 170 is provided on the right side of the front surface of the apparatus main body so that the user can turn on / off the power and perform various settings. The operation panel 170 includes a liquid crystal screen and various buttons that are electrically connected to the control unit 500, and the user can perform button operations while viewing the liquid crystal screen.

  FIG. 4 is a plan view showing a transport driving unit 600 having a drive path from the transport motor 231 to the transport roller 129 and the roll paper spool 112. The recording apparatus 160 is provided with a transport driving unit 600 capable of unwinding and winding the roll paper from the roll paper spool 112 as shown in FIG. The driving force of the conveyance motor 231 that is a driving source of the conveyance driving unit 600 is divided into two paths and transmitted. One path is connected to the transport roller 129 via a pulley and a belt, and transmits driving to transport the roll paper in the forward direction or transport in the return direction. The other path is connected to the roll paper spool 112 via the braking force variable device 116 and a gear train, and is used when the roll paper is rewound.

  When the roll paper is conveyed (sent out) in the forward direction (feed direction), the route is blocked so that the driving force of the drive source (conveyance motor) 231 is not transmitted to the roll paper spool 112. At the same time, as will be described in detail later, each actuator in the braking force varying device 116 is controlled so that a desired braking force acts on the roll paper 111 set. When the conveyance motor 231 is driven to rotate forward in this state, the roll paper 111 can be conveyed at a predetermined speed while applying a predetermined back tension to the roll paper 111.

  When the roll paper is rewound (back-feed in the reverse direction), the transmission path is connected so that the driving force of the drive source (conveyance motor) 231 is transmitted to the roll paper spool 112. At the same time, as will be described in detail later, each actuator in the braking force varying device 116 is controlled so that a desired braking force acts on the roll paper 111 set. By rotating the transport motor 231 in this state, the transport roller 129 and the roll paper spool 112 can be simultaneously reversely rotated (rotated in the rewind direction). In order to apply a desired back tension to the roll paper in this reverse rotation operation, it is necessary to pay attention to the following points when setting the gear ratio in the braking force varying device 116. That is, even if the rotation speed of the roll paper spool 112 is constant, the feed speed changes when the roll diameter of the roll paper 111 changes, and the roll paper feed speed becomes slower as the roll diameter decreases. Therefore, when setting the gear ratio, if the roll paper 111 is not set so that it can be wound even with a diameter slightly smaller than the minimum outer diameter, the winding becomes slack (not possible) during the winding operation (reverse rotation). There is a possibility that the (dissolution) will increase. Therefore, with the braking force variable device 116 having a gear ratio with this point in mind, the feed speed when winding the roll paper 111 is faster than the return conveyance speed of the conveyance roller 129 even if the roll diameter is the minimum diameter. Become. Therefore, the roll paper 111 can be rewound without sagging while applying a predetermined back tension.

  FIG. 5 is an explanatory diagram showing the configuration of the braking force varying device according to the first embodiment. The braking force varying device 116 is composed of several types of actuators such as a gear, an electromagnetic clutch, a torque limiter, and a solenoid. The conveyance motor 231 is connected to the roll paper spool 112 via a drive path including the braking force variable device 116. The driving force of the conveyance motor 231 is transmitted to the transmission shaft 211 via the gear train. An electromagnetic clutch 212 having a gear 213 and an electromagnetic clutch 214 having a gear 215 are attached to the transmission shaft 211. The electromagnetic clutch is configured to have an electromagnet on one side of a rotating iron disk, and to draw a drive force (on) by magnetically attracting the other disk by passing an electric current through it. A type of actuator that can be transmitted. In this electromagnetic clutch, when the current is interrupted, the disk is separated and the power transmission is interrupted. That is, it has a clutch function by turning on and off the current. Therefore, when an ON signal is input to the electromagnetic clutch 212, the rotation of the transmission shaft 211 is transmitted to the gear 213. Similarly, when an ON signal is input to the electromagnetic clutch 214, the rotation of the transmission shaft 211 is transmitted to the gear 215.

  A torque limiter 222 and a torque limiter 223 are attached to a transmission shaft 221 arranged in parallel with the transmission shaft 211 so as to be able to rotate synchronously with the transmission shaft 221. A gear 224 and a stopper gear 225 are fixed to the torque limiter 222. A large number of protrusions are formed at predetermined intervals on the entire circumference of the stopper gear 225. Normally, the torque limiter 222, the gear 224, and the stopper gear 225 are integrally rotatable with the transmission shaft 221. A gear 226 is fixed to the torque limiter 223. Normally, the torque limiter 223 and the gear 226 are integrally rotatable with the transmission shaft 221. Here, the torque limiter has a structure that slides and rotates when a load torque greater than the tightening force (braking force) set by the torque limiter is applied. As an example of a mechanism that generates the tightening force, a coil spring type There is. In this case, a spring with a weak tightening force runs idle with a light force (torque), and a spring with a strong tightening force does not rotate unless a large external force (torque) is applied. In this embodiment, the setting value of the braking force (torque at the start of sliding rotation) of the torque limiter 222 is 3000 g · cm, and the setting value of the braking force (torque at the start of sliding rotation) of the torque limiter 223 is 2000 g · cm. It is.

  The braking force varying device 116 is provided with a solenoid 241 for separating and hooking the L-shaped hooking portion 242 with respect to the protrusion on the circumference of the stopper gear 225. A solenoid is a type of actuator in which a movable iron core is installed in a coil, and the iron core is driven (directly moved) by an electromagnetic force generated by a current flowing in the coil. In the present embodiment, when the solenoid 241 is off, the hooking portion 242 is hooked on a protrusion on the circumference of the stopper gear 225 by an urging force of a spring or the like (not shown), so that the stopper gear 225 is rotated. Stop. On the other hand, when the solenoid 241 is turned on, the stopper gear 225 can be freely rotated by separating the hooking portion 242 from the stopper gear 225 by electromagnetic force. That is, when an ON signal is input to the solenoid 241 to generate an electromagnetic force, the hooking portion 242 is pulled downward to be detached from the stopper gear 224, and the stopper gear 224 can freely rotate. On the other hand, when the solenoid 241 is turned off, the hooking portion 242 is pulled upward by a spring (not shown) to be hooked on the protruding portion of the stopper gear 224, and the rotation of the stopper gear 224 is stopped.

  The braking force varying device 116 is provided with a one-way gear 243 that meshes with the gear 226 on the transmission shaft 221. The one-way gear 243 is a gear incorporating a one-way clutch, and is attached to the fixed shaft 244. A one-way clutch is a clutch that transmits a rotational force in one direction, like a free wheel provided on the rear wheel hub of a bicycle, but transmits only a one-way drive by idling in the reverse direction. The one-way gear 243 rotates freely without resistance in the direction of the arrow shown in FIG. 5, but stops (locks) in the direction opposite to the arrow without being able to rotate because it is fixed to the fixed shaft 244. . For example, when the roll paper 111 is pulled out in the opposite direction to the arrow in FIG. 5 or when the user inadvertently touches the roll paper 111 to pull out the roll paper (opposite to the arrow), this direction is used. Is stopped by the one-way gear 243 via the gear train.

  However, in the configuration of the braking force varying device 116, the torque limiter 223 (rotated at 2000 g · cm or more) is interposed between the roll paper spool 112 and the one-way gear 243. The braking force acts as a back tension. This braking force serves as a back tension that prevents sagging (unwinding) of the roll paper that is pulled out (fed). At that time, if the solenoid 241 is further turned off, the rotation of the stopper gear 225 is stopped by the hook portion 242, and the back tension of the roll paper 111 can be further increased. That is, when the rotation of the stopper gear 225 is stopped, the torque limiter 222 slides and rotates with the set braking force (3000 g · cm), and thus the total back tension of 5000 g · cm is added to the roll paper 111. Will work.

  FIG. 6 is an explanatory diagram showing the state of the braking variable device in FIG. 5 when a weak braking force is generated during conveyance / recording or without roll paper. FIG. 7 is an explanatory diagram showing a state of the braking variable device of FIG. 5 when winding is performed while applying a weak braking force to the roll paper. FIG. 8 is an explanatory diagram showing the state of the braking variable device in FIG. 5 when a strong braking force is generated during conveyance / recording or in a non-operating state with a roll paper set. FIG. 9 is an explanatory diagram showing a state of the braking variable device of FIG. 5 when winding is performed while applying a strong braking force to the roll paper. FIG. 10 is a table showing the relationship between the on / off state of each actuator and the magnitude of the braking force in the braking force variable device of FIG. Next, referring to FIGS. 6 to 10, when transporting / recording (feeding / recording operation of the roll paper 111), when winding the roll paper (rewinding operation), the roll paper set is in a non-operating state. A control operation for changing the strength of the braking force (back tension) of the roll paper 111 in a state where there is no roll paper will be described.

FIG. 6 shows that a relatively weak braking force of 2000 g · cm is applied to the roll paper spool 112 during conveyance / recording (paper feeding / recording operation) or when no roll paper is set in the apparatus main body. The input signal to the actuator is set as follows. Here, “the state without roll paper” and “the state where no roll paper is set” mean a state where the roll paper cannot be conveyed / recorded. Therefore, in addition to the state in which the roll paper spool 112 is not mounted on the apparatus main body, the state in which the roll paper 111 is not fed, the state in which the roll paper is not nipped by the transport roller 129, and the like. This includes a state where recording cannot be performed.
Electromagnetic clutch 212: OFF
Electromagnetic clutch 214: OFF
Solenoid 241: ON (ON)
In such a setting, when the roll paper 111 is unwound in the direction of the arrow when feeding or recording, the gears and the actuators rotate in the direction of the arrow shown in FIG. In this rotation direction, the one-way gear 243 does not rotate (the rotation is locked), so that the set braking force 2000 g · cm of the torque limiter 223 acts on the roll paper 111. At this time, assuming that the winding radius of the roll paper 111 is 5 cm, a braking force (back tension) of 400 g acts on the roll paper 111. Further, when the roll paper 111 is not set, the same braking force is applied to the roll paper spool 112.

In FIG. 7, a relatively weak braking force of 2000 g · cm is applied to the roll paper spool 112 when the roll paper 111 is wound (rewinded). Input signals to the actuators are set as follows.
Electromagnetic clutch 212: OFF
Electromagnetic clutch 214: ON (ON)
Solenoid 241: ON (ON)
In such a setting, when the roll paper 111 is rewound, the set braking force 2000 g · cm of the torque limiter 223 always acts on the roll paper 111. At this time, if the winding radius of the roll paper 111 is 5 cm, the roll paper 111 is wound while receiving a back tension of 400 g.

  In the state of FIG. 7, the driving force of the transport motor 231 is used for returning the roll paper 111 by the transport roller 129 and is also transmitted to the braking force variable device 116. Accordingly, as the conveyance motor 231 is driven, the roll paper 111 is reversely conveyed by the conveyance roller 129, and the roll paper 111 is wound in the arrow direction by rotating the gear trains in the directions indicated by the arrows. Done at the same time. As described above, the rotation ratio of each gear is set so that the winding speed is larger so that the roll paper does not sag even at the minimum winding diameter of the roll paper. On the other hand, since the roll paper is a continuous paper that is relatively difficult to expand and contract, in the winding operation in FIG. 7, the roll paper is wound by means of the return conveyance speed by the nip of the conveyance roller 129 and the braking force variable device 116. Same speed (same speed). Therefore, the torque limiter 223 slides by the amount corresponding to the higher speed on the winding side, and the set braking force 2000 g · cm of the torque limiter 223 acts on the roll paper 111.

FIG. 8 shows a state in which a relatively strong braking force of 5000 g · cm is applied to the roll paper spool 112 during conveyance / recording (paper feeding / recording operation) or when the roll paper is set and inactive. Show. Here, the “non-operating state” means a state where the roll paper is set to be usable, and means a state other than conveyance / recording, winding and unwinding. This includes a power-off state and a power saving state of the recording apparatus. At this time, the input signal to each actuator of the variable braking device 116 is set as follows.
Electromagnetic clutch 212: OFF
Electromagnetic clutch 214: OFF
Solenoid 241: OFF
In such a setting, when the roll paper 111 is unwound in the direction of the arrow when feeding or recording, the gears and the actuators rotate in the direction of the arrow shown in FIG. Since the one-way gear 243 does not rotate (locks) in this rotational direction, the set braking force 2000 g · cm of the torque limiter 223 acts on the roll paper 111. At the same time, the rotation of the stopper gear 225 is stopped (rotation locked) by the hooking portion 242 of the solenoid 241, so that the set braking force 3000 g · cm of the torque limiter 222 also acts on the roll paper 111. Therefore, a strong braking force of 5000 g · cm, which is the sum of the braking force set by the torque limiter 222 and the braking force set by the torque limiter 223, acts on the roll paper 111. Therefore, when the roll paper has a winding radius of 5 cm, the roll paper is wound while receiving a back tension of 1000 g.

FIG. 9 shows a case where a relatively strong braking force of 5000 g · cm is applied to the roll paper spool 112 when the roll paper 111 is wound (rewinded). Input signals to the actuators are set as follows.
Electromagnetic clutch 212: ON (ON)
Electromagnetic clutch 214: ON (ON)
Solenoid 241: ON (ON)
In such a setting, when the roll paper 111 is rewound, a total braking force of 5000 g · cm, which is the sum of the braking force setting 3000 g · cm of the torque limiter 222 and the braking force 2000 g · cm of the torque limiter 223, is applied to the roll paper 111. Will always work. At this time, if the winding radius of the roll paper 111 is 5 cm, the roll paper 111 is wound while receiving a back tension of 1000 g.

  In the state of FIG. 9, the driving force of the transport motor 231 is used to return the roll paper 111 by the transport roller 129 and is also transmitted to the braking force variable device 116. Accordingly, the roll paper 111 is reversely transported by the transport roller 129 as the transport motor 231 is driven, and the roll paper 111 is wound in the arrow direction as each gear train rotates in the arrow direction in FIG. It is done. As described above, the rotation ratio of each gear is set so that the winding speed is larger so that the roll paper does not sag even at the minimum winding diameter of the roll paper. On the other hand, the roll paper is a continuous paper that is relatively difficult to expand and contract. Therefore, in the winding operation in FIG. 9, the roll paper is wound via the return conveyance speed by the nip of the conveyance roller 129 and the braking force variable device 116. Same speed (same speed). Therefore, the torque limiter 222 and the torque limiter 223 slide by the amount corresponding to the higher speed on the winding side, and the set braking force of the torque limiter 222 is 3000 g · cm and the set braking force of the torque limiter 223 is 5000 g · cm. A braking force of cm acts on the roll paper 111.

  FIG. 10 is a table showing the relationship between the on / off state of each actuator and the magnitude of the braking force in the braking force varying device 116. The table of FIG. 10 collectively shows the relationship between the on / off of each actuator of the braking variable device 116 described above and the value of the braking force (back tension acting on the roll paper) in each operation state. . Here, “a state in which no roll paper is set” and “a state in which no roll paper is present” mean a state in which the roll paper cannot be conveyed / recorded. Therefore, in addition to the state in which the roll paper spool 112 is not mounted on the apparatus main body, the state in which the roll paper 111 is not fed, the state in which the roll paper is not nipped by the transport roller 129, and the like. This includes a state where recording cannot be performed.

  Next, the effects obtained by variably controlling the back tension of the roll paper 111 using the aforementioned braking variable device 116 will be described with reference to FIG. According to the brake variable device 116 described above, when the roll paper 111 is not set in the apparatus main body 160 (FIG. 6), the braking force acting on the roll paper spool 112 loaded with the roll paper 111 is relatively weak. The power is set to 2000 g · cm. According to this setting, when the operator inserts the leading end of the roll paper into the apparatus main body while rotating the roll paper spool 112, the operator can insert it with a light operating force, and the operability at the time of inserting the roll paper is improved. In the roll paper conveyance / recording and winding operations, the actuators are configured so that the optimum back tension is applied as shown in the embodiments of FIGS. 6 to 9 according to the type and characteristics of the roll paper. Is switched on / off.

  In a state where the roll paper is set and in a non-operation state other than the conveyance / recording and winding operations (FIG. 8), the braking force acting on the roll paper spool 112 loaded with the roll paper 111 is a strong braking force. It is set to 5000 g · cm. According to this setting, even if the operator accidentally touches the roll paper, the roll paper 111 can be prevented from being easily unwound (unraveled), and convenience in handling is improved. On the other hand, when the roll paper is left in the main body for a long time, when the roll paper is stretched and contracted due to changes in environmental conditions such as temperature and humidity, a force acts in the loosening direction. There are cases where force acts in the loosening direction. Such loosening of the roll paper increases with time. With respect to such a loosening problem, according to the braking variable device 116 described above, as shown in FIG. 8, the braking force acting on the roll paper spool 112 loaded with the roll paper 111 in a non-operating state is a strong braking force of 5000 g. -Since it sets to cm, the above-mentioned roll paper can be prevented from loosening. In addition, since this strong braking force is set with all the actuators turned off, it is effective even when the power of the main body of the apparatus is off. ) Can be effectively prevented. Then, since the roll paper does not come loose during the subsequent transport / recording operation, a constant back tension can be applied to the roll paper, and a clean recorded image can be obtained without image deterioration due to feed fluctuations. Can do.

[Second Embodiment]
FIG. 11 is an explanatory diagram showing the configuration of the braking force varying device 316 used in the recording apparatus according to the second embodiment. The braking force varying device 316 is obtained by adding an additional braking force varying unit 317 for adding a braking force to the braking force varying device 116 according to the first embodiment, and otherwise has the same configuration. That is, the recording apparatus according to the present embodiment is the same as the first embodiment except for the braking force variable device 316 and a part of control of the device. Therefore, for simplification, in the following description of the braking force variable device 316, differences from the braking force variable device 316 will be mainly described, and description of common parts will be omitted as appropriate. In FIG. 11, an electromagnetic clutch 312 having a gear 313 is attached to the transmission shaft 211 in addition to an electromagnetic clutch 212 having a gear 213 and an electromagnetic clutch 214 having a gear 215. In addition to the torque limiter 222 and the torque limiter 223, a torque limiter 322 is attached to the transmission shaft 221 arranged in parallel with the transmission shaft 211 so as to be able to rotate synchronously with the transmission shaft 221. A gear 324 and a stopper gear 325 are fixed to the torque limiter 322. A large number of protrusions are formed at predetermined intervals on the entire circumference of the stopper gear 325. Normally, the torque limiter 322, the gear 324, and the stopper gear 325 are integrally rotatable with the transmission shaft 221. Here, the set value of the braking force (torque at the start of sliding rotation) of the torque limiter 322 is 4000 g · cm.

  The braking force varying device 316 is provided with a solenoid 341 for separating and hooking the L-shaped hooking portion 342 with respect to the protrusion on the periphery of the stopper gear 325. The hook portion 342 is a member for stopping the rotation of the stopper gear 325. In the state where the solenoid 341 is off, the hooking portion 342 is hooked on the protrusion on the circumference of the stopper gear 325 by urging of a spring (not shown) or the like, thereby stopping the rotation of the stopper gear 325. On the other hand, when the solenoid 341 is turned on, the stopper gear 325 can be freely rotated by separating the hooking portion 342 from the stopper gear 325 by electromagnetic force. That is, when an ON signal is input to the solenoid 341 to generate an electromagnetic force, the hooking portion 342 is pulled downward to be detached from the stopper gear 324, and the stopper gear 324 can freely rotate. On the other hand, when the solenoid 341 is turned off, the hooking portion 342 is pulled upward by a spring (not shown) to be hooked on the protruding portion of the stopper gear 324 and the rotation of the stopper gear 324 is stopped.

  The braking force variable device 316 is also provided with a one-way gear 243 that meshes with the gear 226 on the transmission shaft 221. The one-way gear 243 is a gear incorporating a one-way clutch, and is attached to the fixed shaft 244. The one-way gear 243 rotates freely without resistance in the direction of the arrow shown in FIG. 11, but stops (locks) in the direction opposite to the arrow without being able to rotate because it is fixed to the fixed shaft 244. . For example, when the roll paper 111 is pulled out in the direction opposite to the arrow in FIG. 11 or when the user inadvertently touches the roll paper 111 to pull out the roll paper (opposite the arrow), this direction is used. Is stopped by the one-way gear 243 via the gear train. However, even in the configuration of the braking force variable device 316, the torque limiter 223 (rotated at 2000 g · cm or more) is interposed between the roll paper spool 112 and the one-way gear 243, and thus the roll paper 111 has the torque limiter 223. The braking force acts as a back tension. This braking force serves as a back tension that prevents sagging (unwinding) of the drawn roll paper. At this time, if the solenoid 241 is further turned off, the rotation of the stopper gear 225 is stopped by the hooking portion 242 and the back tension of the roll paper 111 can be increased. That is, when the rotation of the stopper gear 225 is stopped, the torque limiter 222 slides and rotates with the set braking force (3000 g · cm), and thus the total back tension of 5000 g · cm is added to the roll paper 111. Will work.

  Further, the braking force varying device 316 is provided with a hooking portion 342 that can be hooked to the stopper gear 325 on the transmission shaft 221 and a solenoid 341 for operating the hooking portion 342. When the solenoid 341 is turned off, the rotation of the stopper gear 325 is stopped by the hooking portion 342, and the back tension of the roll paper 111 can be further increased. That is, when the rotation of the stopper gear 325 is stopped, the torque limiter 322 integrated with the stopper gear 325 slides and rotates with the set braking force, and a back tension of a magnitude further added thereto is applied to the roll paper 111. Can be made. In this embodiment, since the braking force of the torque limiter 322 is set to 4000 g · cm (a torque value at the start of sliding rotation), the torque limiters 223, 222, and 322 are turned off by turning off the solenoid 242 and the solenoid 341. A total of 9000 g · cm of back tension (braking force) can be applied to the roll paper 111. If the solenoid 241 is turned on and the solenoid 341 is turned off, a back tension of 60000 g · cm (2000 g · cm + 4000 g · cm) can be applied to the roll paper 111. The braking force varying device 316 and the recording device using the same according to the present embodiment are configured in the same manner as in the first embodiment except for the above description.

FIG. 12 shows a state in which a strong braking force of 9000 g · cm is applied to the roll paper spool 112 during conveyance / recording (paper feeding / recording operation) or when the roll paper is set and inactive. Here, the “non-operating state” means a state where the roll paper is set to be usable, and means a state other than conveyance / recording, winding and unwinding. This includes a power-off state and a power saving state of the recording apparatus. At this time, the input signal to each actuator of the braking variable device 316 is set as follows.
Electromagnetic clutch 212: OFF
Electromagnetic clutch 214: OFF
Electromagnetic clutch 312: OFF (OFF)
Solenoid 241: OFF
Solenoid 341: OFF

  In such a setting, when the roll paper is inadvertently touched and unwound in the direction in which the roll paper is slack, each gear and each actuator tries to rotate in the direction indicated by the arrow in FIG. However, since the one-way gear 243 does not rotate (rotation lock) in this rotation direction, the set braking force 2000 g · cm of the torque limiter 223 acts on the roll paper 111. At the same time, the hooking portion 242 of the solenoid 241 is hooked on the protrusion of the stopper gear 225 to stop the rotation of the stopper gear 225 (rotation lock), so that the set braking force 3000 g · cm of the torque limiter 222 is rolled. Acts on paper. Furthermore, since the hooking portion 342 of the solenoid 341 is hooked on the protrusion of the stopper gear 325 and the rotation of the stopper gear 325 is stopped, the set braking force 4000 g · cm of the torque limiter 322 acts on the roll paper. That is, when a force in the direction to sag the roll paper 111 is applied, a total braking force of 9000 g · cm of the torque limiters 222, 223, and 322 acts on the roll paper, and this acts as a braking force to form the roll paper. The rotation in the slack direction will be suppressed. As a result, not only during conveyance / recording (paper feeding / recording operation), but also when roll paper is set and not in operation, it is possible to more reliably prevent the roll paper from being loosened.

  FIG. 13 is a table showing the relationship between the on / off state of each actuator in the braking force varying device 316 and the magnitude of the braking force (back tension acting on the roll paper), including the states described above. The braking force varying device 316 according to the present embodiment corresponds to an addition of the additional braking force varying unit 317 to the braking force varying device 316 according to the first embodiment. In a state other than paper feeding, recording, and winding operations, including power off, a braking force 9000 g · cm stronger than the strong braking force 5000 g · cm in the first embodiment is applied to the roll paper 111. Can be applied to the roll paper 111. According to this configuration, the same operational effects as those of the first embodiment can be obtained, and the effect that the roll paper 111 can be more reliably prevented from being loosened when the operator touches the roll paper by mistake.

  In addition, as another method for preventing the roll paper from coming loose, there is a method in which rotation of the roll paper is completely stopped by providing a mechanical lock mechanism without applying an appropriate brake to the rotation of the roll paper. However, in this method, an excessive force may be applied to the recording apparatus main body 160 and the roll paper spool 112 when a strong external force is applied to the roll paper in the rotation direction. It will be difficult to adopt as a countermeasure.

  According to each of the embodiments described above, even if the roll paper is inadvertently touched and tries to rotate in the unwinding direction, a recording apparatus that does not easily cause the roll paper to melt or sag is provided. That is, in the configuration in which the braking force can be changed, the roll paper can be prevented from coming loose by switching the braking force to the heavier one. As a result, during transport / recording, it is operated with a back tension suitable for transport / recording of each roll paper, and in other states such as standby state, power-off state, power saving state, etc. -Roll paper can be prevented from sagging by applying a braking force greater than that during recording. Further, an appropriate back tension can be applied to the roll paper from the beginning to the end of image recording, and a good recorded image can be obtained by stabilizing the conveyance amount while keeping the back tension constant.

  In the above embodiment, the ink jet recording apparatus has been described as an example. However, the present invention can be applied to a recording apparatus that forms an image by other methods such as a thermal transfer type, a laser beam type, a heating type, and a wire dot type. The same applies. Further, the present invention provides a recording operation method such as a serial method in which recording is performed by alternately repeating main scanning by a recording head and sub-scanning by a conveying operation, and a line method in which recording is performed continuously only by sub-scanning by a conveying operation. Regardless, it is equally applicable. The present invention can be similarly applied regardless of the number of recording heads, the type of ink used, the number of properties, and the like. The present invention is also applicable to the case where various different materials such as paper, plastic film, photographic paper, and non-woven fabric are used as the recording medium.

DESCRIPTION OF SYMBOLS 111 Roll paper 112 Roll paper spool 116,316 Braking force variable apparatus 120 Conveyance / recording part 121 Recording head 129 Conveyance roller 160 Recording apparatus (apparatus main body)
211, 221 Transmission shaft 212, 214, 312 Electromagnetic clutch 213, 215, 224, 226, 313, 324 Gear 222, 223, 322 Torque limiter 225, 325 Stopper gear 231 Conveyance motor (drive source of the conveyance driving means)
241 and 341 Solenoid 243 One-way gear 317 Additional braking force variable part 500 Control means 600 Conveyance drive means

Claims (5)

In a recording apparatus for recording an image on a conveyed roll paper by a recording head,
A transport drive means having a braking force varying device capable of unwinding and winding the roll paper from the roll paper spool and capable of varying the braking force of the roll paper to be unwound and wound;
Control means for controlling the braking force varying device so as to change the braking force of the roll paper during the conveyance / recording and winding of the roll paper,
A recording apparatus that controls a braking force of a roll paper when the roll paper is not transported during non-operation to be larger than a braking force of the roll paper when the roll paper is transported.   The recording apparatus according to claim 1, wherein the braking force of the roll paper in a power-off state is greater than the braking force of the roll paper during conveyance for conveying the roll paper.   The recording apparatus according to claim 1, wherein the braking force of the roll paper in the power saving state of the recording apparatus is greater than the braking force of the roll paper during conveyance for conveying the roll paper.   The recording apparatus according to claim 1, wherein a roll paper braking force in a state in which the roll paper is not set is smaller than a roll paper braking force in a non-operating state in which the roll paper is not conveyed.   The recording apparatus according to claim 1, wherein the driving force for rewinding the roll paper is a driving force transmitted from a driving source of a conveyance roller to the roll paper spool via the braking force variable device.

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