JP2007160782A - Printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing device capable of significantly reducing noise at a printing part. <P>SOLUTION: The printing device has a roller pair 14 for transferring roll paper 11 while clamping it, the printing part 17 for printing onto the roll paper 11, and a platen roller 161 for transferring the roll paper 11 supplied via the roller pair 14 to a printing position at the printing part 17. It is composed such that tension applied to the roll paper 11 transferred between the roller pair 14 and the printing part 17 is made variable by drivingly controlling the roller pair 14 and the platen roller 161 with instruction of a control part 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing apparatus used for a receipt issuing machine, a register, or the like.

Conventionally, as a printing device used for a receipt issuing machine or a register, there is one disclosed in Patent Document 1. FIG. 8 shows a schematic configuration of a receipt issuing machine. The roll paper 2 held in the paper storage unit 1 is conveyed through a paper conveyance path 4 having an idler 3, and a printing unit (thermal head) 6 is provided. Printing is performed by contacting the platen (paper transport mechanism) 5 with a predetermined pressure, and then the roll paper 2 is cut by a cutter 7 and issued as a receipt.
JP 11-99715 A

  However, in the case of Patent Document 1 as described above, tension is applied to the roll paper 2 fed to the printing unit 6 from the paper conveyance path 4 by the idler 3 and supplied to the printing unit 6. For this reason, if the roll paper 2 is continuously supplied while printing in the printing unit 6 in this state, a slight vibration at the time of printing of the printing unit 6 is transmitted to the tensioned roll paper 2, which becomes noise. There was a problem that occurred.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a printing apparatus that can significantly reduce noise in a printing unit.

The printing apparatus according to the present invention includes:
A roller pair in which at least one roller for nipping and conveying the roll paper is constituted by a driving roller;
A printing unit for printing on the roll paper;
A platen roller composed of a driving roller that conveys the roll paper supplied via the roller pair to a printing position of the printing unit;
Tension variable means for driving and controlling the roller pair and the platen roller to vary the tension of the roll paper conveyed between the roller pair and the printing unit;
Cutter means for cutting the roll paper printed by the printing means into a predetermined length;
It is characterized by comprising.

  ADVANTAGE OF THE INVENTION According to this invention, the printing apparatus which can reduce the noise in a printing part significantly can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a schematic configuration of a printing apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 11 denotes a roll paper, and this roll paper 11 is held in a paper storage unit 12. The paper storage unit 12 is provided with a paper transport path 13 for transporting the roll paper 11 held in the paper storage unit 12 to the outside.

  A roller pair 14 is disposed in the paper transport path 13. The roller pair 14 includes rollers 141 and 142, and the roll paper 11 is sandwiched between the rollers 141 and 142. The roller 141 is configured as a driving roller by connecting a motor 15 as a rotational driving source to a rotating shaft 141a. The roller 142 is in contact with the roller 141 and conveys the roll paper 11 as the roller 141 rotates. In this case, the roller 142 may also be a driving roller.

  A platen (paper transport mechanism) unit 16 is disposed in the transport path of the roll paper 11 supplied via the roller pair 14. The platen unit 16 conveys the roll paper 11 supplied from the roller pair 14 to a printing position of a printing unit (thermal head) 17. Here, the platen unit 16 includes a platen roller 161 including a driving roller. As shown in FIG. 2A, the platen roller 161 has a hole 161a formed along the center of rotation. A groove 161b is formed on the peripheral surface of the hole 161a. A rotation shaft 162 is inserted through the hole 161a. The rotating shaft 162 is provided with a protrusion 162a in a direction orthogonal to the axial direction. This protrusion 162a is inserted into the groove 161b in the hole 161a. As a result, the platen roller 161 is provided with a play in the rotation direction so that the protrusion 162a can rotate with respect to the rotary shaft 162 in a range where the protruding portion 162a contacts the side walls 161c and 161d of the groove 161b.

  In addition, the method of providing play on the platen roller 161 with respect to the rotation shaft 162 is along the circumferential direction of the peripheral surface of the hole 161a formed along the rotation center of the platen roller 161 as shown in FIG. A plurality of (four in the illustrated example) groove portions 161e are formed at equal intervals, while a plurality of (four in the illustrated example) projecting in the direction orthogonal to the axial direction along the circumferential surface of the rotating shaft 162. The platen roller 161 may be rotatable within a predetermined range with respect to the rotation shaft 162 by forming the portion 162b and inserting the protruding portions 162b into the corresponding groove portions 161e in the hole portion 161a.

  Returning to FIG. 1, the motor 15 is connected to the rotating shaft 162, and is rotated by the motor 15.

  The printing unit 17 is a thermal head having a large number of heating elements, and selectively heats the heating elements in accordance with print data from a driver (not shown) to perform thermal transfer printing on the roll paper 11. .

  A cutter unit 19 is disposed as a cutter unit in the conveyance path of the roll paper 11 printed by the printing unit 17. The cutter unit 19 has a fixed blade 191 and a movable blade 192. The roll paper 11 passing between the fixed blade 191 and the movable blade 192 is cut into a predetermined length by the movement of the movable blade 192, and a receipt is obtained. Output.

  A controller 20 is connected to the motor 15. The control unit 20 controls the start and stop of the operation of the motor 15 and switching between the forward and reverse rotation directions. The tension of the roll paper 11 conveyed between the roller pair 14 and the printing unit 17 together with the motor 15 is variable. The tension variable means is configured.

  Next, the operation of the embodiment configured as described above will be described.

  First, before starting printing, the control unit 20 instructs the motor 15 to rotate backward. The motor 15 reversely rotates in response to this instruction, and reverses the roller 141 of the roller pair 14 and the platen roller 161 by a certain amount at the same speed. With this reverse rotation, in the platen roller 161, the protruding portion 162a of the rotating shaft 162 is brought into contact with the one side wall 161d of the groove portion 161b. That is, the protruding portion 162a of the rotating shaft 162 is taken back by a predetermined distance so that play is generated between the rotating shaft 162 and the platen roller 161 when the rotating shaft 162 is rotated forward.

  From this state, the controller 20 instructs the motor 15 to perform forward (forward) rotation. The motor 15 rotates forward (forward) in response to this instruction. As a result, the roll paper 11 is conveyed to the platen unit 16 via the roller pair 14, printed by thermal transfer at the printing unit 17, and further cut into a predetermined length by the cutter unit 19, and a receipt is output.

  In this case, when the roller 141 of the roller pair 14 starts to rotate due to the forward (forward) rotation of the motor 15, the projection 162a of the rotating shaft 162 is slightly delayed from the other side wall 161c of the groove 161b. Stop rotating and start rotating. That is, the platen roller 161 starts to rotate with a delay by the above-described play amount, and thereafter rotates at the same speed as the roller 141 to convey the roll paper 11. Accordingly, the tension of the roll paper 11 conveyed between the roller 141 and the platen roller 161, that is, between the roller pair 14 and the printing unit 17, is reduced, and the roll paper 11 is conveyed while maintaining this state.

  Accordingly, the roll paper 11 fed to the printing unit 17 from the roller pair 14 can reduce the tension by the rotation delayed by the play of the platen roller 161, so that the printing unit 17 performs printing. However, even if the roll paper 11 is continuously conveyed, the noise generated in the printing unit 17 can be greatly reduced. Further, since the roller 141 and the platen roller 161 of the roller pair 14 are driven by the same motor 15, the apparatus configuration can be simplified and the price can be reduced.

  3 (a) and 3 (b) show the results of confirming this by experiment. FIG. 3 (a) shows that the tension of the roll paper 11 fed from the roller pair 14 to the printing unit 17 is reduced. FIG. 2B shows a state in which the back tension is applied to the roll paper from the idler described above. In this case, a noise meter is installed at a position about 200 mm away from the printing unit 17 on the output side of the receipt, the transport speed of the roll paper 11 is 240 mm / s, the horizontal axis indicates time, and the vertical axis indicates the noise level. . As a result, when the tension of the roll paper 11 shown in FIG. 10A is reduced, the noise level can be significantly reduced compared to the case where the back tension is applied to the roll paper by the idler shown in FIG. Was confirmed.

(Second Embodiment)
FIG. 4 shows a schematic configuration of a printing apparatus according to the second embodiment of the present invention. The same parts as those in FIG.

  In this case, the platen roller 161 is fixed to the rotary shaft 162 without play. The rotation shaft 141a of the roller 141 of the roller pair 14 and the rotation shaft 162 of the platen roller 161 are connected to motors 21 and 22 as rotation drive sources prepared separately. That is, the platen roller 161 and the roller 141 are independently driven to rotate by separate motors 21 and 22.

  In such a configuration, immediately before printing is started, the controller 20 instructs the motor 21 to rotate, and only the roller 141 of the roller pair 14 is rotated by a certain amount. A predetermined amount of roll paper 11 is sent out from the roller pair 14 by the rotation of the roller 141. Next, the control unit 20 instructs the motor 22 to rotate, and thereafter, the platen roller 161 is rotated at the same speed as the roller 141. Accordingly, the tension of the roll paper 11 conveyed between the roller 141 and the platen roller 161, that is, between the roller pair 14 and the printing unit 17, is reduced, and the roll paper 11 is conveyed while maintaining this state.

  Accordingly, even in this case, the tension of the roll paper 11 fed from the roller pair 14 to the printing unit 17 can be reduced, so that the roll paper 11 is continuously conveyed while printing by the printing unit 17. In addition, the noise generated in the printing unit 17 can be greatly reduced. Further, since the roller 141 and the platen roller 161 are driven by independent motors 21 and 22, respectively, by adjusting the rotational speed of the motors 21 and 22, the tension of the roll paper 11 is not generated by noise. It can be adjusted with high accuracy.

(Third embodiment)
FIG. 5 shows a schematic configuration of a printing apparatus according to the third embodiment of the present invention. The same parts as those in FIG.

  In this case, the platen roller 161 is fixed to the rotary shaft 162 without play. A gear 25 is connected to the rotation shaft 141 a of the roller 141 of the roller pair 14, and a gear 26 is also connected to the rotation shaft 162 of the platen roller 161. The gears 25 and 26 are meshed with a gear 28 attached to the rotating shaft 271 of the motor 27. In this case, gears 25 and 26 having different numbers of teeth are used, and the rotation speed of the rotation shaft 141 a of the roller 141 and the rotation speed of the rotation shaft 162 of the platen roller 161 with respect to the rotation of the rotation shaft 271 of the motor 27. The difference is made. Here, the number of teeth of each of the gears 25 and 26 is set so that the rotation speed of the rotation shaft 141a of the roller 141 is slightly larger than the rotation speed of the rotation shaft 162 of the platen roller 161.

  In such a configuration, when the control unit 20 instructs the motor 27 to rotate, the rotation shaft 271 rotates and the rotation is transmitted to the gears 25 and 26 via the gear 28, and the rotation number of the rotation shaft 141 a of the roller 141 is The rotating shaft 162 of the platen roller 161 rotates. In this case, since the rotation speed of the roller 141 is set to be slightly larger than the rotation speed of the platen roller 161 by the gears 25 and 26, it is between the roller 141 and the platen roller 161, that is, the roller pair 14 and the printing unit. The tension of the roll paper 11 conveyed between 17 is gradually reduced.

  Accordingly, even in this case, the tension of the roll paper 11 fed from the roller pair 14 to the printing unit 17 can be reduced, so that the roll paper 11 is continuously conveyed while printing by the printing unit 17. In addition, noise generated in the printing unit 17 can be reduced.

  In this case, if the roll paper 11 is continuously supplied and printing is continuously performed by the printing unit 17, the deflection of the roll paper 11 increases. Therefore, after printing on the roll paper 11 of a certain length by the printing unit 17, the control unit 20 instructs the motor 27 to reversely rotate before the next printing, and the roller 141 and the platen roller 161 are reversed by a certain amount. Thus, the bending of the roll paper 11 is eliminated.

(Fourth embodiment)
FIG. 6 shows a schematic configuration of a printing apparatus according to the fourth embodiment of the present invention. The same parts as those in FIG.

  In this case, a sensor unit 29 serving as a sensor unit that detects the amount of deflection of the roll paper 11 is disposed in the sheet conveyance path between the roller pair 14 and the platen unit 16. In the sensor unit 29, for example, an infrared light LED 291 and a photodiode 292 are arranged so as to sandwich the roll paper 11 as shown in FIG. In this case, the infrared light LED 291 and the photodiode 292 are arranged on the side edge of the roll paper 11 so as to block the light incident on the photodiode 292 from the infrared light LED 291 when the amount of deflection of the roll paper 11 exceeds a predetermined value. It is arranged diagonally. That is, the sensor unit 29 receives the light from the infrared LED 291 with the photodiode 292 when the deflection amount of the roll paper 11 is equal to or less than a predetermined value. This state is detected by blocking light incident on the photodiode 292 from the light LED 291.

  In this way, for example, in the above-described second embodiment, when the amount of deflection of the roll paper 11 becomes equal to or greater than a predetermined value, the operation of canceling the deflection of the roll paper 11 by the output of the sensor unit 29 is performed. If this is done, the tension of the roll paper 11 between the roller pair 14 and the printing unit 17 can be always controlled to be constant, noise at the printing unit 17 can be reduced, and at the same time, the roll paper 11 is deformed too much. Quality deterioration can be prevented. In this case, the same effect can be expected even if the above-described sensor unit 29 is applied to the third embodiment.

  FIG. 7B shows another example of the sensor unit 28. In this case, the reflective sensor 30 is disposed on the surface of the roll paper 11 so as to face the surface. The reflection type sensor 30 can directly measure the distance to the surface of the roll paper 11, and the amount of deflection of the roll paper 11 can be determined by measuring the change in the distance to the surface according to the deflection of the roll paper 11. It detects that it became more than predetermined. Even if it does in this way, the effect similar to having provided the sensor part 29 which has the above-mentioned infrared light LED291 and the photodiode 292 can be acquired.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not change the summary.

  Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. If the above effect is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.

1 is a diagram illustrating a schematic configuration of a printing apparatus according to a first embodiment of the present invention. The figure which shows the cross section of the platen roller used for 1st Embodiment. The figure for demonstrating 1st Embodiment. FIG. 4 is a diagram illustrating a schematic configuration of a printing apparatus according to a second embodiment of the present invention. FIG. 5 is a diagram illustrating a schematic configuration of a printing apparatus according to a third embodiment of the present invention. The figure which shows schematic structure of the printing apparatus concerning the 4th Embodiment of this invention. The figure which shows schematic structure of the sensor part used for 4th Embodiment. 1 is a diagram illustrating a schematic configuration of an example of a conventional printing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Roll paper, 12 ... Paper storage part, 13 ... Paper conveyance path 14 ... Roller pair, 141.142 ... Roller 141a ... Roller shaft, 15 ... Motor 16 ... Platen part, 161 ... Platen roller 161a ... Hole part, 161b ... Groove portion 161c. 161d: Side wall, 161e ... Groove 162: Rotating shaft, 162a ... Projection part 162b ... Projection part, 17: Printing part 19 ... Cutter part, 191 ... Fixed blade, 192 ... Movable blade 20 ... Control part, 21.22 ... Motor 25 .26 ... Gear, 27 ... Motor 271 ... Rotating shaft, 28 ... Gear 29 ... Sensor part, 291 ... Infrared LED
292 ... Photodiode, 30 ... Reflective sensor

Claims (8)

A roller pair in which at least one roller that sandwiches and conveys the roll paper is constituted by a driving roller;
A printing unit for printing on the roll paper;
A platen roller composed of a driving roller for conveying the roll paper supplied via the roller pair to a printing position of the printing unit;
Tension variable means for driving and controlling the roller pair and the platen roller to vary the tension of the roll paper conveyed between the roller pair and the printing unit;
Cutter means for cutting the roll paper printed by the printing means into a predetermined length;
A printing apparatus comprising: The platen roller has a play that is rotatable within a predetermined range with respect to the rotation axis;
The tension variable means rotates the roller pair and the platen roller at the same speed so that the roll paper moves in the transport direction after rotating the roll paper in the direction opposite to the transport direction. The printing apparatus according to claim 1. The printing apparatus according to claim 2, wherein the tension varying unit includes a rotational drive source that rotationally drives the roller pair and the platen roller simultaneously. 2. The tension variable means according to claim 1, wherein after the roller pair is rotated by a certain amount, the roller pair and the platen roller are rotated at the same speed so that the roll paper moves in the transport direction. Printing device. The printing apparatus according to claim 4, wherein the tension varying unit includes a rotational drive source that rotationally drives the roller pair and the platen roller. The printing apparatus according to claim 1, wherein the tension varying unit rotates the roller pair and the platen roller so that a rotation speed of the roller pair is higher than a rotation speed of the platen roller. The printing apparatus according to claim 6, wherein the tension varying unit transmits the rotation of the rotation driving source to the roller pair and the platen roller via a gear mechanism. 7. A printing apparatus according to claim 4, further comprising sensor means for measuring a deformation amount of the roll paper between the roller pair and the printing unit.

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