JP3957519B2 - Printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of deterioration of the printing quality due to drastic sagging by at least a predetermined amount during the printing operation of the tube fed by the feeding unit at the time the top end 41 is contacted with a feeding roller 1 with the tube 4 fed always with a certain amount of sagging by a feeding unit mounted on the upstream side of the printer 1 in the case a tube 4 is set on the printer 1 for executing a printing starting operation, a conveyance roller 15 feeds the top end 41 of the tube 4 to an installation position of a top end detection sensor 18, and then feeds the same backward by a certain amount to a printing starting position. <P>SOLUTION: While feeding the top end 41 to the printing starting position, the sagging amount is controlled so as not to exceed the predetermined amount by providing the feeding speed of the feeding unit at a low level with a small sagging amount. <P>COPYRIGHT: (C)2003,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing apparatus that performs printing on at least the surface of a tube.
[0002]
[Prior art]
The tube may be supplied in a state where it is wound on a large reel having a diameter of several tens of centimeters. The reel is held on a stand so that the central axis can be freely rotated with the center axis being horizontal, and the printing apparatus removes the tube from the reel. You have to print while pulling out.
[0003]
Since the tube is wound on a large reel in this way, a large torque must be applied to the reel in order to start the reel, particularly at the start of printing. However, in particular, when the printing apparatus is a portable type, a large motor cannot be mounted as a motor for driving the conveyance roller. For this reason, there is a problem in that the conveyance force by the conveyance roller is insufficient, slip occurs between the tube and the conveyance roller, or the conveyance roller cannot rotate, and the tube cannot be reliably pulled out from the reel.
[0004]
Therefore, a feeding device that feeds the tube to the transport mechanism by sandwiching the tube with a feed roller in conjunction with the transport by the transport mechanism provided in the printing apparatus is used. This feed roller pulls out the tube from the reel. If there is little slack in the tube between the transport roller and the feed roller, the torque when pulling the tube from the reel affects the transport roller. The tube is fed to the transport roller at a feeding speed in a high-speed operation state faster than the transport speed by, and the tube is bent between the transport roller and the feed roller so that torque fluctuation or large torque does not affect the transport roller. To stabilize the conveyance speed.
[0005]
Note that if the high-speed operation state is continued for a certain period, the amount of sag of the tube is ensured, so the feed speed is set to a low-speed operation state slower than the transport speed, the sag amount is gradually decreased, and the The tube is always controlled to sag between them. When the amount of sag is less than or equal to a predetermined amount, the feeding speed is again set to the high speed operation state to increase the amount of sag.
[0006]
Thus, since the feeding device must operate in synchronism with the operation of the printing device, the feeding device and the printing device are connected to each other through communication cables, for example, and can communicate with each other. It is configured as follows.
[0007]
On the other hand, since the surface of the tube is curved in a cylindrical shape, it is necessary to flatten the tube so that the surface is as flat as possible when attempting to print large on the tube surface. Therefore, in a printing apparatus that prints on a tube, a feed roller is provided on the downstream side of the print head, and the feeding direction of the tube is bent by the feed roller so that the tube follows the platen roller. The platen roller is provided close to the print head, and when the tube is moved along the platen roller by the feed roller, the tube is configured to be flat along the platen roller from a position upstream of the print head. Has been.
[0008]
The tube is flattened by being bent along the platen roller by the feed roller. Since this feed roller is positioned in the transport direction from the transport roller to the print head, when the tube is newly set, the tip of the tube contacts the platen roller and the transport direction is bent toward the print head. The conveyance direction is forcibly bent in the reverse direction by hitting this feed roller.
[0009]
[Problems to be solved by the invention]
When the tube is set in the printing apparatus, the end of the tube is manually pulled out from the reel, and the tube is set at a position where it is sandwiched between the feeding roller and the conveying roller. At this time, the tube is set so that the tip of the tube is located on the upstream side of the print head and between the transport roller and the print head.
[0010]
When the printing start button is pressed in this state, the printing apparatus automatically feeds the tube slightly and is brought into a state of being pressed against the platen roller by the feed roller.
[0011]
In a state where the tube is set manually, the tube is generally not slack between the conveying roller and the feeding roller, and the amount of slack is less than a predetermined amount. Then, as described above, at the same time when the print start button is pressed, the feeding speed is set to a high speed operation state, and the tube is controlled to bend between the conveying roller and the feeding roller.
[0012]
However, when the printing start operation is performed with a relatively thick tube set anew, the tip of the tube contacts the platen roller as described above, hits the feed roller, and the conveyance direction is forcibly bent. . In this way, when the tube is transported in the forward direction from the upstream side to the downstream side in the cueing step of transporting the distal end of the tube to the print start position downstream of the print head at the start of printing, the distal end of the tube is a platen roller. The platen roller and the feed roller act as a resistance against the conveyance of the tube from the time when they contact the roller and collide with the feed roller until they are nipped by the feed roller and the platen roller. When resistance to the tube conveyance occurs, the conveyance roller slips and the tube is not conveyed.
[0013]
Even if the tube is not transported due to the slip of the transport roller, the feed roller feeds the tube in a high-speed operation state. Especially when the cueing process is started in the high-speed operation state, the tube and the transport roller There will be slip in between and the tube will sag more than the preset amount.
[0014]
If the tube bends more than a certain amount, the tube may be bent or hit against a feeding device or other parts, and the tube may not be stably conveyed, which may reduce the print quality.
[0015]
Therefore, in view of the above problems, the present invention has an object to provide a printing apparatus in which a tube is not bent more than necessary at the start of printing even when a tube is newly set in a state where a feeding device is used. To do.
[0016]
[Means for Solving the Problems]
In order to solve the above problems, a printing apparatus according to the present invention includes a print head and a platen facing the print head, and is a printing apparatus that prints a tube, and conveys the tube between the print head and the platen. A transport mechanism is provided on the upstream side of the print head, and there is a mechanism that resists the transport of the tube from the upstream side of the print head to the print start position on the downstream side of the print head. When the amount of sag detected by the sag sensor detecting the amount of sag of the tube between the transportable mechanism and the feedable feeding device that feeds the tube to the transport mechanism falls below a predetermined amount, the amount of sag becomes a constant amount. Control means is provided to increase the feeding speed of the feeding device for a certain period from a low-speed operation state slower than the conveyance speed by the conveyance mechanism to a high-speed operation state faster than the conveyance speed. Bed is characterized in that it does not speed between, increased until the newly set the tip of the tube is conveyed to the print start position.
[0017]
When a new tube is set, a cueing process is performed in which the tip of the tube is transported to the print start position.However, since the print start position is set downstream of the print head, It collides with the feed roller and resists the tube conveyance until it is nipped by the feed roller and the platen roller. Therefore, there is a risk of slipping between the transport roller and the tube, but the feeding speed is not increased while the tip of the tube moves to the print start position, so the tube is not moved between the transport roller and the feed roller. Don't bend more than necessary.
[0018]
A tip detection sensor for detecting the tip of the tube is provided downstream of the feed roller. When a tube is newly set, the tube is conveyed until the tip of the tube is detected by the tip detection sensor. In the printing apparatus that reversely conveys the tip of the tube to the print start position, the feeding speed is not increased at least until the tip of the tube is detected by the tip detection sensor.
[0019]
The sag detecting means for detecting the sag amount may be provided in the feeding device, and the feeding device may be detachably attached.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, reference numeral 1 denotes a printing apparatus, and a separate feeding device 2 is detachably attached to the printing apparatus 1. 3 is a reel around which a long tube 4 is wound, and is held by a stand 31 so as to be rotatable.
[0021]
A cassette mounting portion 11 is provided on the upper surface of the printing apparatus 1. When the tube 4 is set in the printing apparatus 1, the holder 5 is set in the cassette mounting section 11 in advance.
[0022]
Further, the printing apparatus 1 can print on a tape other than the tube 4 and other media. The media other than the tubes 4 are stored in the respective cassettes 6, and the cassette 6 storing the media to be printed is set in the cassette mounting portion 6 instead of the holder 5. Then, the medium pulled out from the cassette 6 is printed.
[0023]
With reference to FIG. 2, a print head 12 and a platen roller 13 facing the print head 12 are attached in the vicinity of the cassette attaching portion 11. The tube 4 is printed on the surface in a state of being sandwiched between the print head 12 and the platen roller 13, and then conveyed to the downstream on the left side in the drawing.
[0024]
A feed roller 14 is provided downstream of the print head 12, and the printed tube 4 is forcibly bent in the transport direction by the feed roller 14 and transported along the platen roller 13, and then from the printing device. Discharged.
[0025]
A pair of transport rollers 15 as a transport mechanism is provided on the upstream side of the print head 12, and the tube 4 is transported to the print head 12 while being sandwiched between the transport rollers 15. Also. A medium sensor 16 is provided on the upstream side of the transport roller 15. The medium sensor 16 is an optical sensor composed of a light projecting unit and a light receiving unit. When the medium is positioned between the light projecting unit and the light receiving unit, the light emitted from the light projecting unit to the light receiving unit is blocked. Thus, it is detected that the medium is located between the light projecting unit and the light receiving unit.
[0026]
A cassette sensor 17 composed of a micro switch is attached to the cassette attaching portion 11, and the cassette sensor 17 is turned on when the cassette 6 is set in the cassette attaching portion 11. A concave portion (not shown) for preventing the cassette sensor 17 from being turned on was formed on the bottom surface of the holder 5 so that the cassette sensor 17 was not turned on even when the holder 5 was set on the cassette mounting portion 11.
[0027]
Similar to the medium sensor 16, an optical tip detection sensor 18 is provided further downstream of the feed roller 14. When the tube 4 is newly set, the tube 4 is transported by the transport roller 15, and the tip 41 of the tube reaches the installation position of the tip detection sensor 18, the light in the tip detection sensor 18 is shielded. It is detected that has reached the installation position of the tip detection sensor 18.
[0028]
A cutter 19 that advances and retreats in the vertical direction in the figure is provided further downstream of the tip detection sensor 18. When the printed portion is conveyed to the position of the cutter 19, the conveyance of the tube 4 is temporarily stopped, and the cutter 19 moves upward in the drawing to cut the tube 4. In addition, the cutting by this cutter 19 can select freely the full cut which cuts the tube 4 completely, and the half cut which leaves a part.
[0029]
Referring to FIG. 3, the feeding device 2 is provided with a pair of feeding rollers 21. When the lid 26 of the feeding device 2 is opened, the space between the feeding rollers 21 is opened as shown in the figure, and the tube 4 can be easily passed between the feeding rollers 21. Then, when the lid 26 is closed, both the feeding rollers 21 approach in conjunction with the operation and pinch the tube 4 with a predetermined stress.
[0030]
A slack roller 22 turns on a slack sensor comprising a micro switch (not shown). The slack roller 22 is forcibly retracted to the illustrated position when the lid 26 is opened, and does not come into contact with the tube 21. When the lid 26 is closed, the retraction is released, and comes into contact with the tube 4 from the lateral direction with a predetermined urging force. The biasing force is set to be relatively small, and the tube 4 is not bent due to the biasing force.
[0031]
The slack roller 22 does not turn on the slack sensor if the tube 4 is deflected in an appropriate amount while the slack roller 22 is in contact with the tube 4, but the slack sensor is turned on when the slack amount of the tube 4 becomes a predetermined amount or less. Then, when the sag sensor is turned on, it is detected that the sag amount of the tube 4 has become a predetermined amount or less.
[0032]
A stay 23 for connection to the printing apparatus 1 protrudes from the side of the feeding apparatus 2, and the feeding apparatus 2 is detachably attached to the printing apparatus 1 by this stay 23. When the feeding device 2 is attached to the printing device 1, the connector 25 provided at the tip of the communication cable 24 is inserted into a connector opened on the side surface of the printing device 1, and between the printing device 1 and the feeding device 2. Communication was made.
[0033]
Referring to FIG. 4, the printing apparatus 1 is provided with a control unit 1a, and signals from the medium sensor 16, the cassette sensor 17, and the tip detection sensor 18 are input to the control unit 1a. And the control part 1a controls the action | operation of the drive motor 10 incorporated in the printing apparatus 1 according to the program set beforehand. The driving force of the drive motor 10 is transmitted to the platen roller 13, the feed roller 14, and the transport roller 15 through a predetermined transmission mechanism. Therefore, the platen roller 13, the feed roller 14, and the transport roller 15 are driven in synchronization with each other.
[0034]
The control unit 1 a communicates with the control unit 2 a built in the feeding device 2 via the communication cable 24. The control unit 2a is connected to a microswitch 22a that is turned on by the sag roller 22 and a drive motor 20 that drives the feed roller 21.
[0035]
With reference to FIG. 5, when the tube 4 is newly set and printing on the tube 4 is started, a cueing process shown in B1 is first performed. In this cueing step, the tip 41 of the tube 4 is moved to a predetermined printing start position. And if the front-end | tip 41 of the tube 4 is moved to a printing start position, the printing process shown to B2 will be performed.
[0036]
When the tube 4 is newly set, the tip 41 of the tube 4 is upstream of the print head 12 and the vicinity of the front end 41 of the tube 4 is sandwiched between the transport rollers 15. When a print start instruction is given in this state, the rotational speed of the drive motor 20 is not increased even if the micro switch 22a is turned on, and the tube 4 is fed in the forward direction at a constant speed ( S1). Therefore, even if the sag of the tube 4 between the transport roller 15 and the feeding roller 21 decreases, control for increasing the amount of sag by increasing the feeding speed of the feeding roller 21 is not performed.
[0037]
Next, the transport roller 15 transports the tube 4 in the forward direction at a predetermined speed. Although the conveyance speed at this time does not need to be the same as the conveyance speed at the time of printing, in this embodiment, the tube 4 is conveyed at the same speed as the conveyance speed at the time of printing. The tip 41 of the tube 4 comes into contact with the platen roller 13 and the conveying direction of the tube 4 is once bent toward the print head 12 side. When the tube 4 is further conveyed, the tip 41 collides with the feed roller 14 and is returned to the platen roller 13 side by the rotation of the feed roller 14, and is then sandwiched between the feed roller 14 and the platen roller 13 and further conveyed. The When the tip 41 of the tube 4 reaches the installation position of the tip detection sensor 18, the normal conveyance is stopped (S3).
[0038]
The fact that the tip 41 has reached the installation position of the tip detection sensor 18 means that the tip 41 is completely held between the platen roller 13 and the feed roller 14 and does not collide with the platen roller 13 or the feed roller 14 again. Therefore, the micro switch 22a that has been disabled is enabled (S4).
[0039]
Subsequently, the transport roller 15 is rotated in the reverse direction by a predetermined amount, and the tube 4 is transported in the reverse direction (S5). Then, when the tip 41 is returned to the state immediately before it is removed from between the feed roller 14 and the platen roller 13, the conveyance in the reverse direction is stopped (S6, S7). Thus, the cueing process B1 is completed. In this embodiment, the micro switch 22a, which is a sag sensor, is activated after stopping the normal conveyance. However, the micro switch 22a may be activated after step 7 in which the reverse conveyance is stopped.
[0040]
When the tip 41 of the tube 4 is thus moved to the print start position, the process proceeds to the printing process. In the printing process B2, first, the tube 4 is transported as it is to secure the front margin, and then the printing process is performed until the printing is completed while transporting the tube 4 at the printing speed (S8, S9).
[0041]
Details of the printing process are shown in FIG. When the cassette sensor 17 of the printing apparatus 1 detects that a cassette 6 containing a medium other than the tube 4 is set (S21), the printer shifts to the single printing mode (S22). In this single printing mode, the printing apparatus 1 performs printing alone. Even if the power switch of the feeding apparatus 2 is turned on and the communication cable 24 is connected to the printing apparatus 1, the operation of the feeding apparatus 2 is performed. Is stopped, the operation of the drive motor 20 that drives the feed roller 21 is prohibited, and the feed roller 21 is not rotated while being held in a stopped state.
[0042]
On the contrary, when the holder 5 is set instead of the cassette 6 (S21), the process proceeds to S23, and the counter is first reset. This counter measures the operation time of the feed roller 21 by counting the number of pulses output to the drive motor 20 that drives the feed roller 21. When the counter is reset, the state of the sag sensor is monitored. When the micro switch 22a, which is a sag sensor, is off, the tube 4 is deflected by a predetermined amount or more, so the feed roller 21 feeds the tube 4 at a speed slower than the transport speed by the transport roller 15 (S24). .
[0043]
If printing is continued as it is, since the conveyance speed is faster than the feeding speed, the sag of the tube 4 gradually decreases, and the micro switch 22a, which is a sag sensor, is turned on. Then, the rotational speed of the feed roller 21 is increased so that the feed speed by the feed roller 21 is faster than the feed speed by the carry roller 15 and a high-speed operation state is set (S26).
[0044]
When the operation state of the feed roller 21 is switched to the high-speed operation state, measurement of the operation time of the feed roller 21 by the counter is started, and the high-speed operation state is continued until the counted number of pulses reaches a preset value and counts up. (S27, S28). Then, after the feed roller 21 rotates for a predetermined time in the high speed operation state, the process proceeds to S24, where the rotation speed of the feed roller 21 is returned to the low speed operation state, and the low speed operation state is maintained until the micro switch 22a is turned on again. To do.
[0045]
By the way, a stop command is constantly monitored during printing. This stop command is output not only when printing is completed, but also when the conveyance of the tube 4 is temporarily stopped during printing. Therefore, when a stop command is issued (S31), it is determined whether it is a stop command due to the end of printing or a stop command due to a temporary stop other than the end of printing such as cutting by the cutter 19 (S32). For example, all information is once cleared and a new print start instruction is waited. If the stop command is temporary except for the end of printing, the previous printing is resumed after the stop command is released without resetting the counter.
[0046]
The determination in step S32 is based on the excitation state of the drive motor 20 that drives the feeding roller 21. The drive motor 20 is a stepping motor. When a stop command is issued, the power supply to the drive motor 20 is stopped and no excitation is performed. However, at other times, the rotation phase of the drive motor 20 is maintained as it is. Thus, the drive motor 20 remains energized. Therefore, when a stop command is issued, the excitation state of the drive motor 20 is checked to determine whether the printing is due to the end of printing or not.
[0047]
In this embodiment, the tube is completely cut or half cut by the cutter 19 after the printing is finished, but in addition to this, the conveyance of the tube is temporarily stopped and a punch is used to make a hole or an overcoat. You may make it perform spraying of an agent.
[0048]
In this embodiment, it is automatically detected whether the holder 5 or the cassette 6 is set and the type of the set medium is discriminated. However, the type of the medium to be printed is manually input. You may comprise as follows.
[0049]
【The invention's effect】
As is apparent from the above description, the present invention sets a new tube and prevents the feeding speed from entering a high-speed operation state until the tip of the tube moves to a predetermined print start position. The tube does not bend more than necessary between the transport roller and the feed roller, and therefore, it is possible to prevent deterioration of print quality due to excessive slack.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention. FIG. 2 is a plan view of a cassette mounting portion. FIG. 3 is a perspective view showing an appearance of a feeding device. FIG. 5 is a flowchart showing the operation at the start. FIG. 6 is a flowchart showing the operation at the time of printing.
DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Feeding apparatus 3 Reel 4 Tube 12 Print head 13 Platen roller 14 Feeding roller 18 Tip detection sensor 21 Feeding roller 22 Slack roller 24 Communication cable

Claims (3)

A printing apparatus that includes a print head and a platen that faces the print head and prints a tube, and a transport mechanism that transports the tube between the print head and the platen is provided on the upstream side of the print head, and the tip of the tube Between the upstream side of the print head and the print start position on the downstream side of the print head, there is a mechanism that resists the conveyance of the tube, and a mountable supply that feeds the tube to the conveyance mechanism. When the amount of slack detected by the slack sensor for detecting the amount of slack in the tube between the feeding device and the transport mechanism falls below a predetermined amount, the feeding speed of the feeding device is controlled by the transport mechanism so that the amount of slack is constant. A control means is provided to increase the speed for a certain period from a low speed operation state slower than the conveyance speed to a high speed operation state faster than the conveyance speed. Until it is conveyed to the position, the printing apparatus characterized by not accelerated. A tip detection sensor that detects the tip of the tube is provided downstream of the feed roller. When a new tube is set, the tube is transported until the tip of the tube is detected by the tip detection sensor. 2. The printing apparatus according to claim 1, wherein the speed is not increased at least until the tip of the tube is detected by the tip detection sensor when the ink is conveyed back to the print start position. 3. A printing apparatus according to claim 1, wherein sag detecting means for detecting the amount of sag is provided in the feeding device, and the feeding device can be detachably attached.

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