JP2005271318A - Thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform head cleaning without performing troublesome cleaning sheet loading work. <P>SOLUTION: The printer 10 is provided with a cleaning mechanism 41 to perform head cleaning for a thermal head 22. The head cleaning mechanism 41 is composed of a cleaning member 42 slidingly contacting a heating element array 22a and scraping dirt off the array and a moving mechanism 43 to move the cleaning member in a main scanning direction. The cleaning member 42 is attached to a carriage 44. The carriage 44 is fixed to a belt 47 and reciprocates in the main scanning direction, guided by a guide member 46 at the time when the belt is rotationally driven by a driving motor 49. The cleaning member 42 is arranged outside the width of the thermal head 22 in a printing mode and is withdrawn from the transfer route of a recording sheet 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal printer for cleaning dirt adhering to a thermal head.

  Thermal printers that record images thermally by heating a thermal head are known. A platen roller is disposed at a head facing position that faces the thermal head. Thermal printers are classified into thermal recording types (thermal printers) that use thermal recording paper (hereinafter simply referred to as recording paper) and thermal transfer types that use a transfer ink ribbon. Thermal printers and platens The recording paper is sandwiched between the rollers, and thermal recording is performed while the recording paper is conveyed in a state where the thermal head is pressed against the recording paper.

  Since the thermal head reaches a high temperature, the protective layer on the surface of the recording paper is softened, and a part of it is attached to the thermal head as dirt. Since this stain causes deterioration of the image quality, the thermal head is cleaned. The thermal head is cleaned, for example, by using a cleaning sheet having a surface coated with an abrasive and feeding it to a printer instead of recording paper. The supplied cleaning sheet passes through the thermal head through the conveyance path. At this time, the cleaning sheet is brought into sliding contact with the thermal head, and dirt adhering to the thermal head is scraped off (for example, see Patent Document 1 below).

  A head cleaning method using a cleaning sheet generally involves a user loading the cleaning sheet into a printer. Ideally, the head cleaning should be performed periodically, but the user tends to neglect cleaning because of the troublesome work of loading the cleaning sheet. The printer described in Patent Document 1 uses a recording paper roll in which a cleaning sheet is provided at the leading end of the recording paper. If this recording paper roll is always used, a regular (roll) The head can be cleaned every time one volume is used up.

JP 2001-47648 A

  However, the recording paper roll with a cleaning sheet is a special product as compared with a standard recording paper roll without a cleaning sheet. Therefore, if it is always used, the cost of consumables becomes high. Regardless of whether you are a business printer user, personal use printer users are unlikely to have access to such expensive consumables.

  An object of the present invention is to provide a thermal printer that does not require a complicated cleaning sheet loading operation and that can perform head cleaning at a reduced running cost.

  The thermal printer of the present invention uses a thermal head in which a plurality of heating elements are arranged in the main scanning direction, and in a thermal printer having a thermal head that thermally records an image by heating the thermal head in pressure contact with a thermal recording material. A head cleaning mechanism comprising: a cleaning member that slidably contacts the thermal head and scrapes off dirt adhering to the head; and a moving mechanism that moves the cleaning member in the main scanning direction in a state where the cleaning member is in contact with the thermal head. It is provided.

  In the print mode, the head cleaning mechanism preferably retracts the cleaning member to the outside of the end portion of the thermal head in the main scanning direction.

  A platen roller that is disposed at a position facing the thermal head and sandwiches the thermal recording material with the head is provided. In the cleaning mode, at least one of the thermal head and the platen roller is displaced between the two. It is preferable to leave a gap through which the cleaning member can enter.

  The moving mechanism preferably includes a carriage that holds the cleaning member, a belt to which the carriage is attached, and a pulley that rotates the belt.

  Preferably, the cleaning member has a polishing portion coated with an abrasive, and the polishing portion and the thermal head are brought into sliding contact to scrape off dirt.

  The thermal printer of the present invention includes a cleaning member that slides on the thermal head and scrapes off dirt adhered to the head, and a moving mechanism that moves the cleaning member in the main scanning direction in a state where the cleaning member is in contact with the thermal head. By providing the head cleaning mechanism comprising the above, it is possible to provide a thermal printer that can perform head cleaning without carrying out a complicated cleaning sheet loading operation. Further, since the head cleaning mechanism is provided, it is not necessary to use a special consumable such as a recording paper roll with cleaning, so that the running cost can be reduced.

  A color thermal printer 10 shown in FIG. 1 is loaded with a recording paper roll 12 in which a long recording paper 11 is wound in a roll shape. As is well known, the recording paper 11 has a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer sequentially provided on a support. The yellow thermosensitive coloring layer, which is the uppermost layer, has the highest thermal sensitivity and develops yellow with a small amount of heat energy. The cyan thermosensitive coloring layer, which is the lowermost layer, has the lowest thermal sensitivity and develops cyan with large heat energy. In addition, the yellow thermosensitive coloring layer loses its coloring ability when irradiated with yellow fixing light which is blue-violet visible light having an emission wavelength peak of about 420 nm. The magenta thermosensitive coloring layer develops magenta with intermediate thermal energy between the yellow thermosensitive coloring layer and the cyan thermosensitive coloring layer, and develops color when irradiated with magenta fixing light having a peak emission wavelength of about 365 nm. The ability is lost.

  The paper feed roller 13 abuts on the recording paper roll 12 and rotates the recording paper roll 12, thereby pulling out the leading end of the recording paper 11 from the roll 12 to the conveyance path. A conveyance roller 16 including a capstan roller 14 and a pinch roller 15 is disposed on the downstream side of the paper feed roller 13. The conveying roller 16 conveys the recording paper 11 in the feeding direction and the returning direction in a nipped state. The transport path is constituted by a guide member (not shown), and the recording paper 11 is transported while being guided by the guide member along the path.

  The paper feed roller 13 and the transport roller 16 are driven to rotate in both forward and reverse directions by the transport motor 17. The conveyance motor 17 is controlled by the controller 21 through a motor driver (not shown). As the carry motor 17, for example, a stepping motor whose rotation amount is determined according to the given number of pulses is used, and the controller 21 counts the drive pulse given to the carry motor 17 to thereby determine the recording start position, The position of the recording paper 11 such as the cutting position and the conveyance amount thereof are specified. The controller 21 includes a CPU, a ROM, a RAM, and the like, and comprehensively controls each unit of the printer.

  A thermal head 22 is disposed on the downstream side of the transport roller 16. The thermal head 22 is a line head that simultaneously records pixels for one line of an image. The direction of this line is called the main scanning direction, and the thermal head 22 includes a heating element array 22a in which a large number of heating elements are arranged in the main scanning direction, as is well known. Then, in a state where the heating element array 22a is in pressure contact with the recording paper 11, each heating element generates heat and heat energy corresponding to the gradation value of the image data is given to the recording paper 11. The thermal head 22 is driven by a head driver based on image data sent from the controller 21.

  A platen roller 23 that supports the recording paper 11 from the back surface is disposed at a head facing position that faces the heating element array 22a. The platen roller 23 is driven and rotated in accordance with the conveyance of the recording paper 11, and stabilizes the contact state between the recording paper 11 and the heating element array 22a. The recording paper 11 is sandwiched between the thermal head 22 and the platen roller 23 to be brought into pressure contact with the heating element array 22a. The thermal recording by the thermal head 22 is performed while the recording paper 11 is transported in the return direction after passing through the thermal head 22 once through the recording area of the recording paper 11 during paper feeding.

  As shown in FIG. 2, the head shift mechanism 24 swings the thermal head 22 to leave a clearance between the heating element array 22a and the platen roller 23 (shown by a broken line and a two-dot chain line in the figure). And the heating element array 22a is swung between a press-contact position (shown by a solid line in the drawing) where the recording element 11 is pressed. At the time of recording, the thermal head 22 moves to the press contact position, and the heating element array 22a is pressed against the recording paper 11.

  There are two types of retreat positions: a paper feed position indicated by a broken line in the figure and a cleaning position indicated by a two-dot chain line in the figure. The paper feeding position is a position where a gap is formed so that the recording paper 11 can pass between the heating element array 22a and the platen roller 23 during paper feeding. The printer 10 is provided with a head cleaning mechanism 41 for cleaning the thermal head 22 as will be described later. The cleaning position of the printer 10 is between the platen roller 23 and the heating element array 22a when the head is cleaned. It is a position that leaves a gap enough to enter. In the cleaning position, the thermal head 22 is further away from the platen roller 23 than in the paper feeding position. For this reason, it is easy to work even when the cleaning member 42 is replaced.

  An optical fixing device 26 is disposed downstream of the thermal head 22 in the feeding direction. The optical fixing device 26 includes a yellow fixing lamp 27 that emits yellow fixing light and a magenta fixing lamp 28 that emits magenta fixing light. The light fixing of the yellow image is performed while the yellow fixing lamp 27 is turned on after the thermal recording of the yellow image is completed, and the recording area is conveyed in the feeding direction as opposed to the thermal recording. Thereafter, thermal recording of the magenta image is started while the recording area is conveyed in the returning direction. At this time, the yellow fixing lamp 27 is turned off. When the thermal recording of the magenta image is completed, the magenta fixing lamp 28 is turned on, and magenta light fixing is started while conveying the recording area in the feeding direction. After the recording area passes through the optical fixing device 26, the conveyance direction is reversed to the return direction, and thermal recording of the cyan image is started.

  A cutter 32 is disposed on the downstream side of the optical fixing device 26. The cutter 32 cuts a recorded portion of the recording paper 11 that has been subjected to thermal recording and fixing into one sheet. The cut sheet is discharged out of the printer from the discharge outlet. The unrecorded portion of the recording paper 11 is rewound onto the recording paper roll 12.

  The cleaning mechanism 41 slidably contacts the heat generating element array 22a to scrape dirt adhering to the array 22a, and moves the cleaning member 42 in the longitudinal direction (main scanning direction) of the heat generating element array 22a. And a moving mechanism 43.

  At the tip of the cleaning member 42, a polishing portion 42a coated with an abrasive is provided. The polishing portion 42a is brought into sliding contact with the heating element array 22a to scrape off dirt.

  The moving mechanism 43 includes a carriage 44, a guide member 46, and a belt 47. The carriage 44 is attached to the groove of the guide member 46 and is held movably in the main scanning direction. The cleaning member 42 is attached to the carriage 44. The cleaning member 42 may be detachably attached to the carriage 44 so that the cleaning member 42 can be replaced when it is consumed.

  One end of the carriage 44 is fixed to the belt 47. The belt 47 is hung on the pulley 48 and is driven to rotate by the rotation of the pulley 48. When the belt 47 rotates, the carriage 44 fixed thereto moves along the main scanning direction while being guided by the guide member 46. The pulley 48 is driven by a drive motor 49. The rotation direction of the belt 47 is determined by the rotation direction of the pulley 48.

  As shown in FIG. 4, the movement range of the carriage 44 is longer than the width of the thermal head 22, and in the print mode, the cleaning member 42 retracts outside the end of the thermal head 22 in the main scanning direction. . For this reason, the carriage 44 does not enter the conveyance path of the recording paper 11 during the print mode. During cleaning, the cleaning member 42 enters the gap between the thermal head 22 and the platen roller 23 to perform head cleaning.

  The carriage 44 reciprocates in the X direction and the Y direction, and microswitches 50a and 50b are arranged at both ends of the movement range. The micro switch 50 has a pair of metal contact pieces, and is turned on when these contact pieces come into contact with each other. The microswitch 50 is connected to the controller 21, and sends a signal to the controller 21 when the tongue piece 52 provided on the carriage 44 is turned on by contacting the metal contact piece. Based on this signal, the controller 21 detects the position of the carriage 44 and switches the rotation direction of the drive motor 49. As a means for detecting the position of the carriage 44, for example, a photo sensor may be used instead of the micro switch.

  The controller 21 switches the operation mode of the printer 10 at a predetermined timing. The initial operation mode is the print mode, and the timing for switching to the cleaning mode is, for example, when a predetermined number of prints have been performed. In addition, the cleaning process may be executed by switching to the cleaning mode when a cleaning instruction is issued from the operation unit, when a predetermined period has elapsed, or when the power is turned on. These timings may be used in combination.

  Hereinafter, the operation of the above configuration will be described. In the print mode, the recording paper 11 is fed when a print instruction is given. When paper is supplied, the thermal head 22 is retracted to the paper supply position, and when the paper is supplied, the thermal head 22 moves to the press contact position. Then, the thermal recording of the image by the thermal head 22 and the optical fixing by the optical fixing device 26 are performed while reciprocating the recording paper 11 in the returning direction and the returning direction.

  When the number of prints reaches a predetermined number, the controller 21 switches to the cleaning mode and operates the cleaning mechanism 41 to execute the cleaning process. First, the thermal head 22 is retracted to the cleaning position, and then the drive motor 49 is rotated to move the carriage 44 from the stop position in the X direction. When the cleaning member 42 enters the gap between the thermal head 22 and the platen roller 23, the polishing portion 42a comes into contact with the heating element array 22a. When the carriage 44 moves in the X direction in this state, the polishing portion 42a comes into sliding contact with the heat generating element array 22a, and the dirt attached to the heat generating element array 22a is scraped off by the friction. When the carriage 44 reaches the micro switch 50a, the micro switch 50a is turned on, the drive motor 49 is reversely rotated, and the carriage 44 moves in the Y direction. Similarly, during this movement, cleaning is performed by the polishing section 42a. When the micro switch 50b is turned on, it further rotates forward and moves the carriage 44 in the X direction.

  The head cleaning is performed by repeating such a reciprocating operation a predetermined number of times. When the head cleaning is completed, the carriage 44 stops at the retracted position outside the width of the thermal head 22 and returns to the print mode. Thus, since the head cleaning is performed by the cleaning mechanism 41, the user does not need to load the cleaning sheet. Further, since the recording paper roll 12 is a standard one that is not provided with a cleaning sheet, the cost of consumables does not increase and the running cost can be reduced.

  In the above embodiment, the example in which the moving mechanism is configured as a moving mechanism dedicated to the cleaning member has been described. However, a rotary cutter that reciprocates the rotary blade in the main scanning direction is used as a printer cut. There is a case where it is arranged in the vicinity of the head. In such a case, the cleaning member may be attached to a carriage to which the rotary blade is attached, and the moving mechanism of the rotary blade and the moving mechanism of the cleaning member may be combined.

  In the above embodiment, the example of scraping dirt with an abrasive has been described, but a brush may be used instead of using an abrasive. In this case, the material of the brush is plastic or metal.

  In the above embodiment, the thermal recording paper that self-colors by heating is used and the thermal printer that heats the thermal recording paper with the thermal head to record the color image has been described as an example. The present invention can also be applied to other printers that use a thermal head, such as a thermal transfer printer that thermally transfers the ink to paper.

It is a block diagram of the color thermal printer of this invention. It is explanatory drawing of the rocking | fluctuation position of a thermal head. It is a block diagram of a cleaning mechanism. It is explanatory drawing which shows the moving range of a cleaning member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Color thermal printer 21 Controller 22 Thermal head 22a Heating element array 23 Platen roller 41 Cleaning mechanism 42 Cleaning member 43 Moving mechanism 49 Drive motor

Claims (5)

In a thermal printer having a thermal head that uses a thermal head in which a plurality of heating elements are arranged in the main scanning direction, presses the thermal head against a thermal recording material, and thermally records an image by heating,
A head cleaning mechanism comprising: a cleaning member that slidably contacts the thermal head and scrapes off dirt adhering to the head; and a moving mechanism that moves the cleaning member in the main scanning direction in a state where the cleaning member is in contact with the thermal head. A thermal printer characterized by being provided.   2. The thermal printer according to claim 1, wherein the head cleaning mechanism retracts the cleaning member to the outside of the main scanning direction end of the thermal head in a print mode.   A platen roller that is disposed at a position facing the thermal head and sandwiches the thermal recording material with the head is provided. In the cleaning mode, at least one of the thermal head and the platen roller is displaced between the two. The thermal printer according to claim 1, wherein a gap through which the cleaning member can enter is opened.   The thermal printer according to claim 1, wherein the moving mechanism includes a carriage that holds the cleaning member, a belt to which the carriage is attached, and a pulley that rotates the belt.   The thermal member according to claim 1, wherein the cleaning member has a polishing portion coated with an abrasive, and the polishing portion and the thermal head are brought into sliding contact to scrape off dirt. Printer.

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