JP2010036425A - Thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To print surely and at high speed without influencing on printing in a thermal printer. <P>SOLUTION: The thermal printer is equipped with a thermal head, an ink ribbon arranged between the thermal head and a printing surface of an object to be printed, and a printing receiving roller which rotates with its peripheral surface contacting to at least a part of the object to be printed into so that the printing surface faces to the ink ribbon. The thermal head presses the ink ribbon to the printing receiving roller side on the downstream in a rotating direction of the printing receiving roller from a contact starting part where a contact between the object to be printed and the ink ribbon is started, in a contact section where the object to be printed and the peripheral surface contact with each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermal printer.

  In recent years, it has been widely demanded to display information such as a production number, a production date, and a shelf life on various target products. In such a case, various information is often displayed on a packaging film or the like for packaging the target product, and thermal printers are widely used for printing various information on the packaging film or the like.

  A thermal printer usually includes a thermal head, an ink ribbon, and a platen roller. The thermal head includes a plurality of heating elements at the end thereof, and a desired heating element generates heat when the thermal printer energizes the thermal head. The ink ribbon is fed from the thermal printer so as to synchronize with a substrate to be printed such as a packaging film continuously fed from a packaging machine or the like. The platen roller comes into contact with a printing material continuously drawn from a packaging machine or the like, and constitutes a print receiving portion for the thermal head and the ink ribbon.

The thermal printer is configured to perform printing by adhering the ink applied to the ink ribbon to the object to be printed by bringing the ink ribbon in contact with the desired heating element on the peripheral surface of the platen roller into contact with the object to be printed. (For example, see Patent Document 1).
Further, in the above-described thermal printer, it is necessary to bond the heated ink to the printed material and to peel the ink ribbon from the printed material while the ink on the ink ribbon is heated by the heating element. . Then, the peeling needs to be performed quickly in order to prevent the ink peeled off from the ink ribbon due to heat from re-adhering (reverse transfer) to the ink ribbon.
Japanese Patent Laid-Open No. 11-123863

  However, when the ink is adhered, the angle formed by the refraction direction of the ink ribbon refracted by contact with the thermal head and the tangential direction of the platen roller at the ink adhesion portion (hereinafter referred to as “peeling angle”) is small. In other words, the substrate to be printed and the ink ribbon are peeled off at the bonding portion in a state where they are close to each other. For this reason, the adhesion of the ink is apt to occur, and there is a possibility that the ink may not adhere to the printed material at the time of peeling and may re-adhere to the ink ribbon. As a result, the thermal printer has a problem that reliable printing may not be performed.

  In this case, for example, a guide portion for guiding the movement of the ink ribbon is provided in the vicinity of the contact portion between the thermal head and the ink ribbon, and the refraction direction of the ink ribbon is set to the feeding direction of the printing object using this guide portion. It is conceivable to increase the peeling angle by arranging the layers so as to have an acute angle.

  However, for example, in the case of the so-called cassette type in which the ink ribbon is configured to be detachable from the thermal printer by the ribbon holder, the above-described guide portion is provided, and the ink ribbon is refracted in the vicinity of the contact portion with the thermal head If the ink cartridge is configured to have an acute angle with respect to the thermal head, the ink ribbon may come into contact with the thermal head when the ribbon holder is attached or detached. When the ink ribbon comes into contact with the thermal head when the ribbon holder is attached / detached, there is a problem that the ink ribbon at the contact portion is cut or wrinkled and cannot be used.

  In this case, for example, it is conceivable that a moving mechanism capable of moving the thermal head is provided in a cassette-type thermal printer, and the thermal head is released in advance with a predetermined stroke when the ribbon holder is attached or detached. This makes it possible to avoid contact between the thermal head and the ink ribbon when the ribbon holder is attached or detached.

  However, in recent years, in thermal printers that require higher performance, smaller size, etc., it is difficult to secure a space for providing the above-described stroke in the thermal head or to provide a separate mechanism as described above. There was a problem of being.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a thermal printer capable of performing printing at high speed and reliably without affecting printing.

  The thermal printer according to the present invention includes a thermal head, an ink ribbon disposed between the thermal head and a printing surface of the printing material, and at least the printing material so that the printing surface faces the ink ribbon. A print receiving roller that rotates while contacting a part thereof with the peripheral surface, and wherein the thermal head has a contact section where the print target and the peripheral surface are in contact with each other. The ink ribbon is pressed toward the print receiving roller on the downstream side in the rotation direction of the print receiving roller from the contact start portion where contact is started.

  Further, it is preferable that the thermal head is configured to be able to approach or leave the print receiving roller.

  The thermal printer further includes a head holder that holds the thermal head and a ribbon holder that holds the ink ribbon, and the ribbon holder is preferably configured to be detachable from the head holder. .

  According to the present invention, in a thermal printer, printing can be performed at high speed and surely without affecting printing.

  Hereinafter, a thermal printer 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 11.

  1 and 2 are external perspective views showing the external appearance of a thermal printer 1 according to an embodiment of the present invention. FIG. 3 is an external perspective view showing the mounting surface 20a side of the ribbon cassette 2 holding the ink ribbon R according to the present embodiment. As shown in FIGS. 1 and 2, a thermal printer 1 according to this embodiment includes a ribbon cassette 2 that is a ribbon holder, a printer main body 3 that is a head holder, a platen roller 4 that is a print receiving roller, It is mainly composed.

  The ribbon cassette 2 feeds out the ink ribbon R at a high speed (for example, 80 mm / s or more) while synchronizing with the packaging film W that is a printing object continuously fed out from a packaging machine (not shown). The printer main body 3 includes a thermal head 61, and the thermal head 61 has a plurality of heating elements at its end 61a. The thermal head 61 is configured such that a desired heating element generates heat when the thermal printer 1 energizes the thermal head 61. The platen roller 4 makes a peripheral surface contact the packaging film W in a predetermined contact section, and constitutes a print receiving portion for the thermal head 61 and the ink ribbon R.

  As described above, the thermal printer 1 according to this embodiment is applied to the ink ribbon R by bringing the ink ribbon R in contact with the desired heat generating element that has generated heat into contact with the packaging film W on the peripheral surface of the platen roller 4. The ink is adhered to the packaging film W to perform printing. Further, as shown in FIG. 2, the thermal printer 1 according to the present embodiment is configured so that the ribbon cassette 2 can be attached to and detached from the printer main body 3. That is, the thermal printer 1 according to the present embodiment constitutes a so-called cassette type thermal printer.

  First, the ribbon cassette 2 will be described. The ribbon cassette 2 holds the first ribbon core R1 around which the unused ink ribbon R is wound and the second ribbon core R2 around which the ink ribbon R after the printing is wound, and the ink ribbon R Is conveyed along a predetermined conveying path from the upstream side (first ribbon core R1 side) to the downstream side (second ribbon core R2 side).

  As shown in FIG. 3, the ribbon cassette 2 includes a rectangular cassette base 20, and on the mounting surface 20 a side, a raw fabric holder 21, a first guide roller 22, a second guide roller 23 a, The 3rd guide roller 23b, the electrostatic removal board 24, the 4th guide roller 23c, the winding holder 5, the 1st insertion pin 25a, the 2nd insertion pin 25b, and the 3rd insertion pin 25c are arrange | positioned.

  In the following description, an upper end portion of the ribbon cassette 2 (cassette base 20) in a state where the ribbon cassette 2 is mounted on the printer main body 3 (see FIGS. 1 and 2) is referred to as a first end portion 20c. The end opposite to the first end 20c in the height direction is the second end 20d, the end opposite to the second end 20d in the width direction is the third end 20e, and the second end 20e is the second end 20e in the height direction. The end opposite to the third end 20e will be described as a fourth end 20f.

  Also, the side edge connecting the first end 20c and the second end 20d is the first side edge 20g, the side edge connecting the second end 20d and the third end 20e is the second side edge 20h, A side edge connecting the third end portion 20e and the fourth end portion 20f will be referred to as a third side edge 20i, and a side edge connecting the fourth end portion 20f and the first end portion 20c will be described as a fourth side edge 20j.

  Furthermore, the direction from the first end 20c to the second end 20d is a first direction D1, the direction from the second end 20d to the third end 20e is a second direction D2, and from the third end 20e. A direction toward the fourth end 20f is defined as a third direction D3, and a direction from the fourth end 20f toward the first end 20c is defined as a fourth direction D4. Further, the direction from the mounting surface 20a of the cassette base 20 to the printer body 3 in a state where the ribbon cassette 2 is mounted on the printer body 3 is a fifth direction D5, and the direction opposite to the fifth direction D5 is a sixth direction D6. explain.

  A first ribbon core R1 is attached to the original fabric holder 21. The original fabric holder 21 is formed in a columnar shape, and is rotatably attached to the cassette base 20 around a rotation axis extending in the fifth direction D5 in the vicinity of the first end 20c. Further, a guide pulley 21 a is provided at the starting end portion (end portion on the sixth direction D6 side) of the raw fabric holder 21. The guide pulley 21 a is hung on the winding holder 5 by a timing belt 26 and is configured to be interlocked with the rotation of the winding holder 5. The original fabric holder 21 rotates in conjunction with the rotation of the winding holder 5 to supply the ink ribbon R from the first ribbon core R1.

  The first guide roller 22 guides the ink ribbon R supplied from the first ribbon core R1 to the transport path. The first guide roller 22 is provided in the vicinity of the first side edge 20g on the lower side (first direction D1 side) of the original fabric holder 21, and is formed on the cassette base 20 around the rotation axis extending in the fifth direction D5. It is mounted for rotation. The first guide roller 22 receives the ink ribbon R sent out from the first ribbon core R1 on the circumferential surface, and guides the ink ribbon R so as to be conveyed in the first direction D1 along the first side edge 20g.

  The second guide roller 23a and the third guide roller 23b guide the ink ribbon R guided by the first guide roller 22 to a printing section provided in the transport path. The fourth guide roller 23c is guided by the third guide roller 23b, and guides the ink ribbon R after printing to the second ribbon core R2.

  The second guide roller 23a is attached to the cassette base 20 so as to be rotatable around a rotation axis extending in the fifth direction D5 in the vicinity of the second end 20d. The second guide roller 23a guides the ink ribbon R guided from the first guide roller 22 to be conveyed in the first direction D1 along the first side edge 20g in the vicinity of the second end 20d. In the printing section provided between the second end 20d and the third end 20e, the ink ribbon R is guided so as to be conveyed in the second direction D2 along the second side edge 20h. That is, the second guide roller 23a changes the transport direction of the ink ribbon R from the first direction D1 to the second direction D2 in the vicinity of the second end 20d.

  The third guide roller 23b is rotatably attached to the cassette base 20 around a rotation axis extending in the fifth direction D5 in the vicinity of the third end 20e. The third guide roller 23b guides the ink ribbon R guided from the second guide roller 23a in the vicinity of the third end portion 20e so as to be conveyed in the second direction D2 along the second side edge 20h. The ink ribbon R is guided so as to be conveyed in the third direction D3 along the third side edge 20i from the third end 20e. That is, the third guide roller 23b changes the transport direction of the ink ribbon R from the second direction D2 to the third direction D3 in the vicinity of the third end 20e.

  The fourth guide roller 23c is provided in the vicinity of the third side edge 20i on the upper side (third direction D3 side) of the third end portion 20e, and the cassette base 20 is centered on the rotation axis extending in the fifth direction D5. It is attached to be rotatable. The fourth guide roller 23c guides the ink ribbon R guided by the third guide roller 23b so as to be conveyed in the third direction D3 along the third side edge 20i above the third end portion 20e. At the same time, the ink ribbon R is guided to the second ribbon core R2.

  The electrostatic removal plate 24 is disposed between the third guide roller 23b and the fourth guide roller 23c. In the vicinity of the third side edge 20i, the electrostatic removal plate 24 is on the conveyance path so as to be substantially parallel to the printing surface of the ink ribbon R conveyed in the third direction D3 along the third side edge 20i. Provided. A static elimination sheet is attached to the electrostatic removal plate 24 to release the charge when the ink ribbon R being transported is charged. The electrostatic removal plate 24 releases the charge charged to the ink ribbon R. Provided for.

  A second ribbon core R2 is attached to the winding holder 5. The winding holder 5 is formed in a cylindrical shape, and is rotatably attached to the cassette base 20 around a rotation axis X1 extending in the fifth direction D5 in the vicinity of the fourth end 20f. Here, in FIG. 4, the partial expanded sectional view showing the axial cross section of the winding holder 5 which concerns on this embodiment is shown. As shown in FIG. 4, the winding holder 5 includes a fixed portion 51 that is fixed to the cassette base 20, a rotating portion 52 that is rotatably supported by the fixing portion 51, and a holder hub 53 that is fitted into the rotating portion 52. , And a guide pulley 54 connected to the rotating portion 52.

  The fixing portion 51 is formed in a substantially cylindrical shape extending in the fifth direction D5, and is fixed to the cassette base 20 by a plurality of screw members 55. A plurality of ball bearings 51 a are provided on the outer peripheral surface of the fixed portion 51. The plurality of ball bearings 51a support the rotating portion 52 around the rotation axis X1.

  The rotating part 52 is formed in a substantially cylindrical shape extending in the fifth direction D5, and the second ribbon core R2 is attached thereto. Further, the rotating part 52 is provided with a recessed part 52a capable of accommodating the fixing part 51 on the starting end side (sixth direction D6 side). The rotating part 52 is rotatably attached to the fixing part 51 in a state where the fixing part 51 is accommodated in the recess 52a. The rotating part 52 can rotate around the rotation axis X1 with respect to the fixed part 51 by using the ball bearing 51a as a bearing.

  On the other hand, a fitting insertion portion 52b into which the holder hub 53 can be fitted is provided on the distal end side (the fifth direction D5 side) of the rotating portion 52. The insertion portion 52b is formed in substantially the same shape as the outer shape of the holder hub 53, and the rotating portion 52 is provided with a screw member (not shown) that fixes the holder hub 53 after the holder hub 53 is inserted. Yes. The rotating part 52 fixes the holder hub 53 with a screw member (not shown) after the holder hub 53 is inserted into the insertion part 52b.

  The holder hub 53 is formed in a substantially cylindrical shape, and a drive hole 53a into which a ribbon drive shaft 7 described later can be inserted is provided on the rotation shaft. The holder hub 53 includes a pair of first guide grooves 53 b that can be engaged with the ribbon drive shaft 7 inserted into the drive hole 53 a, and the first guide groove 53 b with respect to the rotation axis X <b> 1 of the winding holder 5. And a pair of second guide grooves 53c provided at positions rotated by a predetermined degree. The pair of first guide grooves 53b and the pair of second guide grooves 53c form a cross-shaped groove with respect to the drive hole 53a. The pair of first guide grooves 53b and the pair of second guide grooves 53c are formed so as to be able to engage with a part of a ribbon drive shaft 7 (a pair of roller parts 73 described later) inserted into the drive hole 53a. The rotational force transmitted from the ribbon drive shaft 7 is transmitted to the rotating unit 52. Further, as shown in FIG. 4, the holder hub 53 is formed so that the surface of the tip end portion (tip portion on the fifth direction D5 side) is substantially horizontal. The tip of the holder hub 53 formed in a substantially horizontal plane plays a role of assisting insertion of the ribbon drive shaft 7 that positions the insertion position while rotating.

  The guide pulley 54 is connected to the rotating portion 52 on the starting end side of the rotating portion 52. A timing belt 26 that is hung around the guide pulley 21 a of the original fabric holder 21 is wound around the guide pulley 54, and the rotational force of the rotating portion 52 is transmitted to the original fabric holder 21.

  The first insertion pin 25a, the second insertion pin 25b, and the third insertion pin 25c are fitted in the first insertion portion 35a, the second insertion portion 35b, and the third insertion portion 35c provided in the printer body 3. It is formed to be insertable.

  On the mounting surface 20b side of the cassette base 20, as shown in FIG. The grip portion 27 is used when the printer body 3 is attached to or detached from the printer body 3. Further, the cassette base 20 is formed with a through hole 28 through which the cassette base 20 passes. The through hole 28 exposes a switch unit 34 described later provided in the printer main body 3.

  Next, the printer body 3 will be described. FIG. 5 is an external perspective view showing the external appearance of the printer main body according to the present embodiment. FIG. 6 is a front view of the printer main body 3 according to the present embodiment. As shown in FIGS. 5 and 6, the printer main body 3 is mainly configured by a drive unit 30 that holds the ribbon cassette 2 and a main body unit 31 that holds the drive unit 30.

  The drive unit 30 is configured to be movable in a fifth direction D5 and a sixth direction D6 with respect to the main body 31 by a drive motor (not shown) provided in the main body 31. That is, the thermal printer 1 according to the present embodiment is configured such that the drive unit 30 that holds the ribbon cassette 2 is movable in the fifth direction D5 and the sixth direction D6, and the fifth direction D5 and the sixth direction of the drive unit 30 are configured. The area in the width direction (fifth direction D5 or sixth direction D6) of the ink ribbon R held in the ribbon cassette 2 can be effectively used in conjunction with the movement to D6.

  The drive unit 30 includes a frame unit 32, a ribbon sensor 33, and a switch unit 34. The frame part 32 constitutes the skeleton of the drive part 30 and holds the ribbon cassette 2. Moreover, the frame part 32 has the 1st insertion part 35a, the 2nd insertion part 35b, and the 3rd insertion part 35c which extend in the 6th direction D6, and the 1st insertion part 35a, the 2nd insertion part. The portion 35b and the third insertion portion 35c are formed so that a first insertion pin 25a, a second insertion pin 25b, and a third insertion pin 25c provided on the cassette base 20 can be inserted. Specifically, the first insertion portion 35a is formed so that the first insertion pin 25a can be inserted, and is provided at a position corresponding to the first insertion pin 25a. Moreover, the 2nd insertion part 35b is formed so that the 2nd insertion pin 25b can be inserted, and it is provided in the position corresponding to the 2nd insertion pin 25b. The third insertion portion 35c is formed so that the third insertion pin 25c can be inserted therein, and is provided at a position corresponding to the third insertion pin 25c. The frame portion 32 causes the first insertion pin 25a, the second insertion pin 25b, and the third insertion pin 25c to be inserted into the first insertion portion 35a, the second insertion portion 35b, and the third insertion portion 35c. Thus, the ribbon cassette 2 is held and fixed to the drive unit 30.

  The ribbon sensor 33 is disposed on the transport path of the ink ribbon R in a state where the ribbon cassette 2 is mounted on the printer main body 3. The ribbon sensor 33 includes a sensor transmitter 33a and a sensor receiver 33b. The sensor transmitter 33a and the sensor receiver 33b are arranged to face each other with a predetermined distance therebetween. ing. The ribbon sensor 33 detects that the ink ribbon R is inserted between the sensor transmitter 33a and the sensor receiver 33b.

  The switch unit 34 starts and stops the thermal printer 1. The switch part 34 has a button part 34a and a button base part 34b. The button part 34a is pressed by the user when starting and stopping the thermal printer 1. The button base portion 34 b exposes the button portion 34 a from the through hole 28 of the cassette base 20 when the ribbon cassette 2 is mounted on the printer main body 3.

  The main body 31 is formed in a rectangular box shape and holds the drive unit 30. The main body 31 has a thermal head unit 6, a ribbon drive shaft 7, and a control unit (not shown). The control unit rotates the thermal head unit 6 in accordance with a predetermined program, and causes the thermal head 61 provided in the thermal head unit 6 to perform predetermined printing. In addition, when the ribbon cassette 2 is mounted, the control unit causes the ribbon sensor 33 to detect the presence of the ink ribbon R, thereby rotating the ribbon drive shaft 7 around the rotation axis X2 at a predetermined speed. The rotation of the ribbon drive shaft 7 ends when it is detected that the ribbon cassette 2 is mounted on the printer main body 3. Moreover, you may comprise so that rotation of the ribbon drive shaft 7 may be stopped when predetermined time passes.

  FIG. 7 is a front view of the printer main body 3 and the platen roller 4 showing the arrangement of the thermal head unit 6 and the platen roller 4 according to the present embodiment when not printing. FIG. 8 is a front view of the printer main body 3 and the platen roller 4 showing a contact state during printing between the thermal head 61 and the platen roller 4 according to the present embodiment.

  The thermal head unit 6 includes a thermal head 61 having a heating element (not shown) at an end portion 61a, a head bracket 62 for fixing the thermal head 61, a head bracket 62, and the thermal head 61 and the head bracket 62. And a head driving unit 63 that rotates the ink around a predetermined rotation axis, and is disposed in the vicinity of the ink ribbon R that is conveyed in the printing section.

  The thermal head 61 has a chamfered end 61a, and a plurality of heating elements are arranged on the chamfered end 61a. The plurality of heating elements are configured such that a desired heating element generates heat when the thermal head 61 is energized in response to a command from the main body 31.

  The head bracket 62 fixes the thermal head 61 to the head driving unit 63 so that the thermal head 61 is supported by the head driving unit 63 at a predetermined inclination angle. The head bracket 62 according to the present embodiment is configured such that the inclination angle of the thermal head 61 with respect to the horizontal direction is larger than that of the conventional head bracket. In other words, the head bracket 62 fixes the thermal head 61 to the head driving unit 63 in a state where the thermal head 61 is raised in the vertical direction from the conventional one.

  The head drive unit 63 rotatably supports the thermal head 61 fixed to the head bracket 62 around a rotation axis extending in the sixth direction D6. Specifically, the head drive unit 63 moves the thermal head 61 from the initial position where the thermal head 61 fixed to the head bracket 62 is positioned on the inner side of the main body 31 (see FIG. 7) to the outer side of the main body 31. And the thermal head 61 and the ink ribbon R are rotated to a printing position (see FIG. 8) where printing is performed on the packaging film W.

  Here, the thermal head 61 performs printing on the packaging film W by pressing the end 61 a against the peripheral surface of the platen roller 4. The end portion 61a is chamfered, and a heating element is disposed in the chamfered portion. Therefore, in order to print on the packaging film W, the end 61a needs to be brought into contact with the peripheral surface at a predetermined angle. However, in the present embodiment, the thermal head 61 is held by the head drive unit 63 in a state where the thermal head 61 is inclined to the vertical direction side with respect to a predetermined angle. Thus, in order to bring the end portion 61 a into contact with the circumferential surface at a predetermined angle, the contact portion between the platen roller 4 and the end portion 61 a needs to be brought into contact with the downstream side of the top portion A of the platen roller 4.

  Furthermore, the platen roller 4 according to the present embodiment is arranged on the second direction D2 side from the conventional one so that the thermal head 61 can come into contact with the downstream side of the top portion A of the platen roller 4. ing. For example, 10 mm is arranged on the second direction side. Further, the head drive unit 63 performs thermal in the contact section defined by the contact end portion where the contact ends from the contact start portion where the contact between the peripheral surface of the platen roller 4 and the packaging film W starts at the printing position. The thermal head 61 is rotated at a predetermined stroke so that the head 61 presses the ink ribbon R against the peripheral surface of the platen roller 4 on the downstream side in the rotation direction of the platen roller 4 from the top A in the vertical direction of the platen roller 4. Let Thereby, the end portion 61a of the thermal head 61 can be brought into contact with the peripheral surface at a predetermined angle.

  The ribbon drive shaft 7 is inserted into a drive hole 53 a provided in the winding holder 5 when the ribbon cassette 2 is mounted on the printer main body 3. The ribbon drive shaft 7 is supported so as to be rotatable about the rotation axis X <b> 2, and transmits the rotational force applied from the main body portion 31 to the winding holder 5.

  FIG. 9 is a partially enlarged cross-sectional view showing an axial cross section of the ribbon drive shaft 7. FIG. 10 is a partially enlarged cross-sectional view showing a state in which the ribbon drive shaft 7 is inserted into the holder hub 53. Further, FIG. 11 shows a partially enlarged sectional view showing a state in which the holder hub 53 slides on the ribbon drive shaft 7.

  As shown in FIG. 9, the ribbon drive shaft 7 is formed so as to be inserted into the support hole 74 and the drive hole 53a, which are rotatably supported by the main body 31, and the pair of first guide grooves 53b or the pair of first guide grooves 53b. 2 The guide part 71 which can be engaged with the guide groove 53c, the connection part 72 which connects the guide part 71 and the support part 74, and the guide pulley 75 are comprised.

  The support portion 74 includes a fixing portion 74b that is fixed to the main body portion 31 by a plurality of screw members 76, and a base portion 74c that is rotatably supported by the fixing portion 74b. The fixed part 74b is provided with a plurality of ball bearings 74a, and the ball bearings 74a pivotally support the base part 74c.

  The connecting portion 72 is connected to the base portion 74c. The connecting portion 72 is formed in a substantially cylindrical shape extending in the sixth direction D6 and is constricted toward the rotation axis X2 of the connecting portion 72. In other words, the connecting portion 72 is formed so that the shaft diameter at the center portion is thinner than the shaft diameter at both end portions, and is easily bent as a whole.

  The guide part 71 is formed in a substantially cylindrical shape, and is connected to the connection part 72 around the rotation axis X <b> 2 of the connection part 72. A pair of roller portions 73 are provided on the peripheral surface of the guide portion 71 so as to be rotatable about a rotation axis X3 orthogonal to the rotation axis of the connecting portion 72 (rotation axis of the guide portion 71) X2. ing.

  The pair of roller portions 73 are formed so as to roll inside the pair of first guide grooves 53b or the pair of second guide grooves 53c along the pair of first guide grooves 53b or the pair of second guide grooves 53c. (See FIGS. 10 and 11). In the thermal printer 1, the pair of roller portions 73 can roll inside the pair of first guide grooves 53b or the pair of second guide grooves 53c along the pair of first guide grooves 53b or the pair of second guide grooves 53c. By being formed in this manner, the drive unit 30 can move in the fifth direction D5 and the sixth direction D6 with respect to the main body 31 while the winding holder 5 is held.

  The guide pulley 75 is connected to the rotating portion 74 c of the base portion 74 on the starting end side (the fifth direction D5 side) of the ribbon drive shaft 7. A timing belt wound around a motor (not shown) provided inside the main body 31 is wound around the guide pulley 75, and the rotational force from the motor is transmitted to the rotating portion.

  The platen roller 4 rotates while bringing the packaging film W continuously conveyed from the packaging machine (not shown) and the peripheral surface into contact with each other in a predetermined contact section (see FIG. 8). The rotation of the platen roller is performed in conjunction with the drive of the drive unit 30 in the fifth direction D5 or the sixth direction D6, whereby the thermal printer 1 performs printing in the width direction of the ink ribbon R. The area can also be used effectively.

  Next, the operation of the thermal printer 1 according to this embodiment will be described. The user first prepares the ribbon cassette 2. That is, the user attaches the first ribbon core R1 to the original fabric holder 21 and attaches the second ribbon core R2 to the winding holder 5. At this time, the user sets the ink ribbon R in the state of the first guide roller 22, the second guide roller 23a, the third guide roller 23b, and the fourth guide roller 23c in the order along the predetermined transport path. To put on.

  Next, the user grips the grip portion 27 of the ribbon cassette 2 and attaches the ribbon cassette 2 to the printer main body 3. Here, in the thermal printer 1 according to the present embodiment, a ribbon sensor 33 is provided in the printer main body 3. The ribbon sensor 33 is configured to be able to detect the ink ribbon R when the ribbon cassette 2 is mounted. When the ribbon sensor 33 detects the insertion of the ink ribbon R by mounting the ribbon cassette, the main body 31 rotates the ribbon drive shaft 7 at a low speed for a predetermined time. Accordingly, for example, the ribbon is caused by a shift of the stop position between the pair of first guide grooves 53b or the pair of second guide grooves 53c of the drive hole 53a provided in the winding holder 5 and the pair of roller portions 73. Even in a state where the drive shaft 7 cannot be inserted into the take-up holder 5, it is possible to easily eliminate the deviation of the stop position by rotating the ribbon drive shaft 7 at a low speed. The ribbon drive shaft 7 can be inserted into the winding holder 5.

  When the pair of first guide grooves 53b or the pair of second guide grooves 53c and the pair of roller portions 73 cancel the deviation of the stop position and the ribbon drive shaft 7 can be inserted into the winding holder 5, The ribbon cassette 2 is attached to the printer body 3. When the ribbon cassette 2 is mounted on the printer main body 3, the ribbon drive shaft 7 stops rotating. When the ribbon cassette 2 is mounted, the thermal head unit 6 is in a state where the thermal head 61 is in the first position. Therefore, the ribbon cassette 2 is mounted without causing the ink ribbon R to interfere with the thermal head 61. It becomes possible to make it.

  When the attachment of the ribbon cassette to the printer main body is completed, printing based on a predetermined program is started when the user presses the switch button.

  The thermal printer 1 according to the present embodiment having the above-described configuration has the following effects.

  In the thermal printer 1 according to this embodiment, in the contact section where the peripheral surface of the platen roller 4 and the packaging film W are in contact, the thermal head 61 is rotated in the rotational direction of the platen roller 4 rather than the top portion A in the vertical direction of the platen roller 4. The ink ribbon R is configured to be pressed against the peripheral surface of the platen roller 4 on the downstream side. Therefore, it is possible to increase the peeling angle α formed by the refraction direction of the ink ribbon R refracted by the contact with the thermal head 61 and the tangential direction of the platen roller 4 at the ink adhesion portion (see FIG. 8). . For example, when the thermal head 61 and the ink ribbon R are brought into contact with each other at the top A of the platen roller 4 as in the prior art, only a peeling angle of about 14 ° could be ensured. , A peeling angle of 39 ° can be ensured. Thereby, for example, when the peeling angle α is small, the printed material and the ink ribbon are peeled at the bonding portion in a state where the printed material is close to each other. However, in this embodiment, since the peel angle α can be increased, the ink ribbon R can be attached to the packaging film W due to insufficient peel angle. It is possible to reduce the influence on the printed image. That is, it becomes possible to perform printing reliably.

  This also applies to the case where, for example, the ink ribbon R is fed out at a high speed (for example, 80 mm / s or more) while being synchronized with the packaging film W that is a printing material continuously fed out from the packaging machine.

  In addition, it is possible to provide a section in which the ink ribbon R and the packaging film W are conveyed in close contact immediately before the printing portion of the end portion 61a of the thermal head 61. Therefore, the speed difference between the ink ribbon R and the packaging film W can be eliminated in the section immediately before printing of the thermal head 61. Thereby, it becomes possible to reduce the printing defect due to the speed deviation between the ink ribbon R and the packaging film W.

  Further, it is possible to perform printing so that the end portion 61 a of the thermal head 61 is pressed in a direction toward the rotation axis of the platen roller 4. Therefore, for example, even when the platen roller is formed of an elastic material such as rubber, the print receiving portion can be elastically deformed evenly. Thereby, it becomes possible to make it hard to be influenced by printing.

The thermal printer 1 according to the present embodiment includes a ribbon sensor 33 that detects the proximity of the ink ribbon R when the ribbon cassette 2 is mounted. Further, the thermal printer 1 is configured to rotate the ribbon drive shaft 7 at a low speed for a certain time when the ribbon sensor 33 detects the proximity of the ink ribbon R. For this reason, for example, the ribbon drive is performed by a shift of the stop position between the pair of first guide grooves 53b or the pair of second guide grooves 53c of the drive hole 53a provided in the winding holder 5 and the pair of roller portions 73. Even in a state where the shaft 7 cannot be inserted into the take-up holder 5, the ribbon drive shaft 7 rotates at a low speed, so that the deviation of the stop position can be easily eliminated, and the ribbon drive shaft 7 can be easily taken up. Can be inserted. As a result, the ribbon cassette 2 can be easily attached to the printer body 3.
The tip of the holder hub 53 is formed flat, and the pair of roller portions 73 are formed in a rotatable roller shape. For this reason, the pair of roller portions 73 rotate to facilitate insertion of the holder hub 53 into the pair of first guide grooves 53b or the pair of second guide grooves 53c. As a result, the ribbon cassette 2 can be easily attached.

  Further, the thermal printer 1 according to the present embodiment is formed so that the connecting portion 72 of the ribbon drive shaft 7 can be bundled toward the rotation axis X2. For this reason, the connecting portion 72 is easily bent and the eccentricity generated between the ribbon drive shaft 7 and the winding holder 5 can be absorbed by the connecting portion 72. Thereby, the rotational force transmitted by the ribbon drive shaft 7 can be reliably transmitted to the winding holder 5.

  Further, the thermal printer 1 according to the present embodiment is configured in a cassette type. That is, the ribbon cassette 2 holding the ink ribbon R is configured to be detachable from the printer main body 3. Therefore, for example, replacement and maintenance of the ink ribbon R are facilitated. Further, for example, by removing the ribbon cassette 2, the printer main body 3 is exposed, so that maintenance of the printer main body 3 is facilitated.

  Further, the thermal printer 1 according to the present embodiment is configured such that the thermal head 61 is close to or away from the platen roller 4. Specifically, the thermal head 61 is configured to be rotatable about the head driving unit 63 in the printer main body 3. Therefore, even in a cassette-type thermal printer in which the ribbon cassette 2 holding the ink ribbon R can be detached from the printer main body 3, for example, contact between the thermal head 61 and the ink ribbon R is avoided when the ribbon cassette 2 is detached. Is possible. This makes it possible to avoid damage to the ink ribbon R that may occur when the ribbon cassette 2 is attached or detached.

  Further, the thermal head 61 according to the present embodiment is configured to be rotatable by the head driving unit 63. Therefore, for example, a space for driving the head driving unit 63 can be reduced. As a result, a cassette type thermal printer can be configured without increasing the size of the thermal printer 1.

  The thermal printer 1 according to the present embodiment is configured such that the ribbon cassette 2 can be driven with respect to the printer main body 3. Therefore, it is configured to be movable also with respect to the packaging film W flowing through the platen roller 4. Therefore, it is possible to use the area in the width direction of the ink ribbon R without waste.

  In addition, this invention is not limited to the said embodiment at all, and the technical scope of this invention is not limited to this.

  In the present embodiment, the ribbon drive shaft 7 is configured to be bent easily by forming the connecting portion 72 of the ribbon drive shaft 7 so as to be constricted toward the rotation shaft. Not limited to. For example, the connection part 72 may be configured to bend easily by continuously forming portions with different shaft diameters in the connection part 72. Further, for example, the connection portion 72 may be made of a low-rigidity material so that the connection portion 72 is easily bent. Thus, in the present invention, any configuration may be used as long as the connecting portion 72 is easily bent.

  In the present embodiment, the holder hub 53 is provided with a cross-shaped groove including a pair of first guide grooves 53b and a pair of second guide grooves 53c. However, the present invention is not limited to this. For example, it is good also as a structure which has only a pair of 1st guide groove 53b, and it is good also as a structure which has several guide grooves, such as a pair of 3rd guide groove and a pair of 4th guide groove.

1 is an external perspective view showing an external appearance of a thermal printer according to an embodiment of the present invention. It is an external appearance perspective view which shows the external appearance of the thermal printer which concerns on the said embodiment. It is an external appearance perspective view which shows the mounting surface side of the ribbon holder with which the ink ribbon which concerns on the said embodiment was mounted. It is a partial expanded sectional view showing the axial cross section of the winding holder which concerns on the said embodiment. It is an external appearance perspective view which shows the external appearance of the printer main body which concerns on the said embodiment. It is a front view of the printer main body which concerns on the said embodiment. FIG. 3 is a front view of the printer main body and the platen roller showing an arrangement state when the thermal head unit and the platen roller according to the embodiment are not printed. FIG. 3 is a front view of the printer main body and the platen roller showing a contact state during printing between the thermal head and the platen roller according to the embodiment. It is a partial expanded sectional view showing the axial section of the ribbon drive shaft concerning the embodiment. It is a partial expanded sectional view which shows the state by which the ribbon drive shaft was inserted in the holder hub which concerns on the said embodiment. It is a partial expanded sectional view which shows the state which a holder hub slides on the ribbon drive shaft which concerns on the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal printer 2 Ribbon holder 3 Printer main body 4 Platen roller 5 Take-up holder 6 Thermal head unit 7 Ribbon drive shaft 30 Drive part 31 Main part 33 Ribbon sensor 53 Holder hub 53a Drive hole 53a
53b First keyway 53c Second keyway 61 Thermal head 62 Head bracket 63 Head drive unit R Ink ribbon W Printing film

Claims (3)

Thermal head,
An ink ribbon disposed between the thermal head and the printing surface of the substrate;
A print receiving roller that rotates while contacting at least a part of the printed material with the peripheral surface so that the print surface faces the ink ribbon;
The thermal head is downstream in the rotation direction of the print receiving roller in a contact section where the printed material and the peripheral surface are in contact with each other than a contact start portion where contact between the printed material and the ink ribbon is started. A thermal printer, wherein the ink ribbon is pressed toward the print receiving roller side.   The thermal printer according to claim 1, wherein the thermal head is configured to be close to or separated from the print receiving roller. A head holding body that holds the thermal head; and a ribbon holding body that holds the ink ribbon,
The thermal printer according to claim 1, wherein the ribbon holder is configured to be detachable from the head holder.

Images