JP4273870B2 - Printing device - Google Patents

Description

  The present invention relates to a technique for removing rolls of roll paper.

The thermal transfer printing device can change the print density finely and can express continuous gradation like a photograph, which is difficult with other methods. For example, images taken with a digital camera Are widely used for business purposes, such as a printing apparatus that prints the image, and a printing apparatus that creates a sticker print from an image taken by a camera provided.
In such a thermal transfer printing apparatus for business use, roll paper is used. However, since the roll paper has a curl, there is a problem that curls remain after printing and are difficult to use. Therefore, as a mechanism for solving such a problem, for example, a mechanism that corrects curl by bending the roll paper in a direction opposite to the direction in which the roll paper was wound has been proposed (for example, Patent Documents). 1).
JP-A-4-338570

  By the way, in a thermal transfer printing apparatus for business use, large-capacity roll paper and ink ribbon are used so that consumables such as printing paper and ink ribbon need not be replenished. There is a method to reduce the diameter of the roll paper core as a way to increase the capacity of the roll paper, but if the diameter of the roll core is reduced, a strong curl will be attached to the part near the core. It becomes. Patent Document 1 describes a technique for correcting the curl of the roll paper, but this technique is limited to bending in a direction opposite to the curl, depending on the degree of curl. The correction degree is not adjusted. For this reason, the technique described in Patent Document 1 cannot correct the curl of large-capacity roll paper.

  The present invention has been made under the background described above, and provides a technique for adjusting the degree of correction of the curl of the printing paper according to the roll diameter of the roll paper on which the printing paper is wound. Objective.

In order to solve the above problems, a printing apparatus according to the present invention rotates a roll paper made of printing paper wound around a supply shaft, and detects a winding diameter of the roll paper and a feeding means for feeding out the printing paper. The supply shaft is located on the downstream side in the transport direction of the print paper as viewed from the detection unit and a printing unit that performs printing on the print paper, and on the upstream side in the transport direction of the print paper as viewed from the discharge port. A roller for conveying the printing paper fed out from
A groove extending in a direction parallel to the rotation axis of the roller, sandwiching the printing paper between the rollers, facing the roller, and recessed to receive the roller, and an edge of the groove from the edge of the printing paper A paper guide having a plate-like portion that protrudes upstream in the conveying direction and guides the printing paper to the groove; and a printing paper that is fed from the supply shaft and positioned downstream in the conveying direction from the roller. When printing is performed by being sent to a printing unit upstream of the roller in the transport direction, the roller and the paper guide groove are relatively positioned so that the printing paper does not hit the edge of the paper guide groove. The distance is controlled, and after the printing on the printing paper is finished, the printed paper is pushed toward the groove of the paper guide by the roller while feeding the printing paper downstream in the transport direction. And a control means for curving the printing paper in a direction that eliminates curl caused by being wound around the supply shaft, and the control means is configured to control the roller according to the winding diameter detected by the detection means. And a relative distance between the groove and the paper guide.
According to the printing apparatus of this printing paper is the core set curl by grooves recessed roller and the paper guide is curved in the opposite direction, the bending degree, the position of the roller is controlled in accordance with the winding diameter of the printing paper Is controlled.

  According to the present invention, it is possible to adjust the degree of correction of the curl of the printing paper according to the winding diameter of the roll paper on which the printing paper is wound.

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

[A. Constitution]
FIG. 1 is a diagram showing a configuration of a thermal transfer printing apparatus according to an embodiment of the present invention. In FIG. 1, illustration of an ink ribbon and a mechanism for transporting the ink ribbon is omitted to prevent the drawing from becoming complicated. In the following description, a thermal transfer type printing apparatus will be described as an example. However, the printing method is not limited to the thermal transfer method, and other printing methods may be used.

  The supply shaft 10 is a shaft for rotating the roll paper 5 made of the printing paper 1 wound around the supply shaft 10 and is rotated by a motor (not shown). The guide roller 20 is for changing the conveyance direction of the printing paper. The main feed roller 30 conveys the printing paper 1 fed out by rotating the supply shaft 10 in the direction of arrow A or arrow B in FIG. 1, and is rotated by a motor (not shown). The thermal head 50 has a heating element (not shown), and its heat generation is controlled by a control device (not shown) included in the printing apparatus. The platen roller 40 conveys the printing paper 1. The platen roller 40 presses the ink ribbon (not shown) and the printing paper 1 against the thermal head 50. When the control device controls the heating element of the thermal head 50 and heat is applied to the ink ribbon pressed by the platen roller 40, the heat-applied portion of the ink is welded to the printing paper 1.

  The feed roller 60 conveys the printing paper 1 in the direction of arrow C or arrow D in FIG. 1, and is rotated by a motor not shown. The first paper guide 70 guides the printing paper 1 conveyed via the feed roller 60 to the cutter 80. The cutter 80 cuts the printing paper 1 and cuts the printing paper 1 guided by the first paper guide 70 into a predetermined length under the control of the control device. The paper discharge roller 240 conveys the printing paper 1, is rotated by the power transmitted from the feed roller 60 via a gear (not shown), and is guided by the second paper guide 250 and the third paper guide 260. The printed printing paper 1 is discharged in the direction of arrow C in FIG.

  Next, the curl correction mechanism provided in the printing apparatus according to the present embodiment will be described. The curl correction mechanism is roughly constituted by the motor 100, the paper discharge roller 240, the first lever 170, the second lever 180, and the third paper guide 260. FIG. 2 shows a main configuration of the curl correction mechanism.

  A worm gear 120 and an encode plate 110 provided with a plurality of slits in the radial direction are mounted on the shaft of the motor 100. A first gear 130 is engaged with the worm gear 120, and a second gear 140 attached to the curl correction cam drive shaft 150 is engaged with the first gear 130. When the motor 100 is rotationally driven under the control of a control device (not shown), the worm gear 120 rotates as the shaft of the motor 100 rotates. This rotation is transmitted to the curl correction cam drive shaft 150 via the first gear 130 and the second gear 140, and the curl correction cam 160 mounted on the curl correction cam drive shaft 150 rotates.

  The sensor 115 is, for example, a transmissive photosensor, and includes a light emitting element that emits light and a light receiving element that receives light and emits an electrical signal. When the light emitted from the light emitting element is incident on the light receiving element, the transmission type photosensor outputs an ON signal indicating that the light is incident on the light receiving element to the control device. When the light emitted by is not incident on the light receiving element, an off signal indicating that no light is incident on the light receiving element is output to the control device. The sensor 115 is arranged so that the encode plate 110 passes between the light emitting element and the light receiving element. Therefore, when the encode plate 110 rotates with the rotation of the shaft of the motor 100, the sensor 115 is provided on the encode plate 110. The ON signal and the OFF signal are alternately output by the slit. For example, the control device counts the number of rotations of the motor 100 by counting the number of ON and OFF signals output from the sensor 115, and the curl correction cam 160 rotated by the motor 100 is counted from the number of rotations. The rotation angle of the curl correction cam 160 is controlled by calculating the rotation angle.

As shown in FIG. 3, the first lever 170 is disposed so that the end thereof is in contact with the curl correction cam 160, and the first lever support shaft 270 is centered as the curl correction cam 160 rotates. It is designed to rotate. As shown in FIG. 3, the other end of the first lever 170 includes a bearing 280 </ b> C and a support portion 175 that rotatably supports the paper discharge roller 240.
The second lever 180 rotatably supports the paper discharge roller 240, and supports the paper discharge roller 240 with a bearing 280A provided at the end. The other end of the second lever 180 is provided with a bearing 280B, and the second lever 180 is rotated around a pin 290 penetrating the bearing 280B. .
When the first lever 170 rotates as shown in FIG. 4 along with the rotation of the curl correction cam 160, the paper discharge roller 240 moves away from the third paper guide 260. When the first lever 170 is rotated as shown in FIG. 5 along with the rotation of the curl correction cam 160, the paper discharge roller 240 approaches the third paper guide 260 accordingly.

The first idle gear 210 disposed on the third lever 190 is engaged with the second idle gear 220 disposed on the third lever, and the gear 230 mounted on the paper discharge roller 240. The second idle gear 220 is rotated by the rotation transmitted from the feed roller 60 via a gear (not shown). When the second idle gear 220 rotates, this rotation causes the first idle gear 210 to rotate. The paper discharge roller 240 that is transmitted to the gear 230 and supported by the second lever 180 and the fourth lever 200 rotates.
The third paper guide 260 is for removing the curl attached to the printing paper 1 and has a semicircular groove formed in the longitudinal direction.

Next, a roll diameter detection mechanism provided in the printing apparatus according to the present embodiment will be described. FIG. 6 is a diagram illustrating the main configuration of the roll detection mechanism.
The roll diameter detection lever 300 is rotatable about a support shaft 310, has a roller 320 at the end, and a light-shielding portion 300a at the other end. The roller 320 is for allowing the roll diameter detection lever 300 to rotate following the winding diameter of the roll paper 5 without damaging the roll paper 5. The roll diameter detection lever 300 can be rotated by a pin 330. Is attached. The sensors 340A and 340B are sensors for detecting the winding diameter of the roll paper 5, and are arranged at different angles as shown in FIG. The sensors 340A and 340B are transmissive photosensors similar to the sensor 115, and are arranged so that the light shielding portion 300a of the roll diameter detection lever 300 passes between the light emitting element and the light receiving element.

  When the roll diameter of the roll paper 5 is large, that is, when the light shielding portion 300a is between the light emitting element and the light receiving element of the sensor 340A, the sensor 340A outputs an off signal. When the use of the printing paper 1 progresses and the roll diameter detection lever 300 rotates and the light-shielding portion 300a is not positioned between any of the light emitting elements and the light receiving elements of the sensors 340A and 340B, the sensors 340A and 340B are used. Both output an ON signal. When the use of the printing paper 1 further progresses, the roll diameter of the roll paper 5 becomes small, the roll diameter detection lever 300 rotates, and the light shielding unit 300a is positioned between the light emitting element and the light receiving element of the sensor 340B. 340B outputs an off signal.

Next, control performed by the control device (not shown) according to the winding diameter of the roll paper 5 will be described. The curl of the printing paper 1 is weak at a portion away from the supply shaft 10 and becomes stronger as it is closer to the supply shaft 10. Therefore, the control device determines the winding diameter of the roll paper 5 from the signals output from the sensors 340A and 340B, controls the rotation of the curl correction cam 160, and adjusts the degree of curvature of the printing paper 1.
Specifically, the control device rotates the motor 100 when the signal output from the sensor 340A is an off signal, that is, when the roll paper 5 has a large winding diameter and the printing paper 1 has a weak curl. The curl correction cam 160, the first lever 170, and the second lever 180 are rotated so that the paper discharge roller 240 is positioned at the position shown in FIG. As shown in FIG. 7, the printing paper 1 is in a direction opposite to the direction in which the roll paper is curled by the paper discharge roller 240 and the semicircular groove formed in the third paper guide. Curled and curled.

  In addition, when the signals output from the sensors 340A and 340B are both ON signals, that is, when the use of the printing paper 1 is advanced and the roll diameter of the roll paper 5 is smaller than that at the new time, the control device 100 is rotated, and the curl correction cam 160, lever A, and lever B are rotated so that the paper discharge roller 240 is positioned at the position shown in FIG. As the use of the printing paper 1 progresses and the roll diameter of the roll paper 5 becomes smaller, the curl attached to the printing paper 1 becomes stronger accordingly, so that the printing paper 1 is bent more than that shown in FIG. 7, as shown in FIG. Let the curl be corrected.

  Further, when the signal output from the sensor 340B is an off signal, that is, when the use of the printing paper 1 further progresses and the winding diameter becomes small, the control device rotates the motor 100 and moves the position shown in FIG. The curl correction cam 160, the lever A, and the lever B are rotated so that the paper discharge roller 240 is positioned at the same position. Since the curl of the printing paper 1 is stronger as it is closer to the supply shaft 10, as shown in FIG. 9, the printing paper 1 is curved more than that shown in FIG. 8 to correct the curling.

[B. Operation]
Next, the operation of this embodiment will be described. In the following description, the operation when the roll diameter of the roll paper 5 is large, that is, when the roll paper 5 is weak, will be described. Next, the use of the printing paper 1 proceeds and the roll paper 5 The operation when the winding diameter becomes medium and when the winding diameter of the roll paper 5 becomes small will be described.

[1. Operation when roll paper roll diameter is large]
When the printing apparatus is operated by the user and an instruction to perform printing is input, the control apparatus (not shown) outputs a signal output from the sensor 115 so that the curl correction cam 160 is in the state shown in FIG. Is used to rotate the motor 100. When the motor 100 is driven and the worm gear 120 mounted on the shaft of the motor 100 rotates, this rotation is transmitted to the curl correction cam drive shaft 150 via the first gear and the second gear, and the curl correction cam 160 rotates. To do. When the curl correction cam 160 rotates as shown in FIG. 4, the first lever 170 in contact with the curl correction cam 160 rotates about the first lever support shaft 270 in the direction of arrow A in FIG. 2. . When the first lever 170 rotates in the direction of arrow A in FIG. 2, the second lever 180 rotates about the pin 290 in the direction of arrow C in FIG. 2. When the second lever 180 rotates in the direction of arrow C, the paper discharge roller 240 supported by the second lever 180 is separated from the third paper guide 260 as shown in FIG. .

When the paper discharge roller 240 is separated from the third paper guide 260, the control device starts printing. The control device controls the platen roller 40 and presses the printing paper 1 and an ink ribbon (not shown) against the thermal head. Next, the control device rotates the supply shaft 10 and the main feed roller 30 to convey the printing paper 1 in the direction of arrow D in FIG. 1 and controls the thermal head 50 to print the ink ribbon ink. It is welded to the paper 1. When printing is completed, the control device detects the winding diameter of the roll paper 5 and rotates the curl correction cam 160.

  When the roll diameter of the roll paper 5 is large, that is, when the light shielding portion 300a of the roll diameter detection lever 300 is between the light emitting element and the light receiving element of the sensor 340A, the sensor 340A outputs an off signal. When the signal output from the sensor 340A is an off signal, the control device (not shown) controls the motor 100 so that the paper discharge roller 240 is positioned at the position shown in FIG. Specifically, the motor 100 is controlled, the curl correction cam 160 is rotated, and the first lever 170 is rotated in the direction of arrow B in FIG. When the first lever 170 is rotated in the arrow B direction, the second lever 180 is rotated in the arrow D direction in FIG. When the second lever 180 is rotated in the direction of arrow D, the paper discharge roller 240 supported by the second lever 180 is moved to the position shown in FIG.

  Next, the control device controls the platen roller 40 to separate the printing paper 1 and the ink ribbon from the thermal head 50, and then rotates the supply shaft 10, the main feed roller 30, and the paper discharge roller 240, The printing paper 1 on which printing has been performed is conveyed in the direction of arrow C in FIG. When the printing paper 1 is conveyed in the direction of arrow C in FIG. 1, the printing paper 1 with the curl is wound by the paper discharge roller 240 and the third paper guide 260 as shown in FIG. 7. It is conveyed while being bent in the opposite direction. When the control device transports the printing paper 1 having a predetermined length, the control device controls the cutter 80 to cut the printing paper 1. When the printing paper 1 is cut, the control device rotates the paper discharge roller 240 to discharge the cut printing paper 1 from the paper discharge port cover 90.

[2. Operation when roll diameter is medium]
Next, an operation when the use of the printing paper 1 progresses and the roll diameter of the roll paper 5 becomes medium will be described. Since the operation from the start of printing to the end of printing is the same as the operation when the roll diameter of the roll paper 5 is large, the description thereof is omitted.

  When the use of the printing paper 1 proceeds from the state in which the new roll paper 5 is loaded, and the light shielding portion 300a of the roll diameter detection lever 300 is not between the light emitting element and the light receiving element of either the sensor 340A or the sensor 340B. Both the sensor 340A and the sensor 340B output an ON signal. When the signals output from the sensors 340A and 340B are both ON signals, the control device (not shown) controls the motor 100 so that the paper discharge roller 240 is positioned at the position shown in FIG. Specifically, the motor 100 is controlled, the curl correction cam 160 is rotated, and the first lever 170 is rotated in the direction of arrow B in FIG. When the first lever 170 is rotated in the direction of arrow B, the second lever 180 is rotated in the direction of arrow D in FIG. 2, and the discharge roller 240 supported by the second lever 180 is It is moved to the position shown in.

  Next, the control device controls the platen roller 40 to separate the printing paper 1 and the ink ribbon from the thermal head 50, and then rotates the supply shaft 10, the main feed roller 30, and the paper discharge roller 240. Then, the printed printing paper 1 is conveyed in the direction of arrow C in FIG. When the printing paper 1 is conveyed in the direction of arrow C in FIG. 1, the printing paper 1 with the curl is moved by the paper discharge roller 240 and the third paper guide 260 as shown in FIG. It is conveyed while being curved in the direction opposite to the curl with a degree of curvature larger than the degree of curvature shown in FIG. When the control device transports the printing paper 1 having a predetermined length, the control device controls the cutter 80 to cut the printing paper 1. When the printing paper 1 is cut, the control device rotates the paper discharge roller 240 to discharge the cut printing paper 1 from the paper discharge port cover 90.

[3. Operation when roll paper roll diameter is small]
Next, an operation when the use of the printing paper 1 further progresses and the roll diameter of the roll paper 5 becomes small will be described. Since the operation from the start of printing to the end of printing is the same as the operation when the roll diameter of the roll paper 5 is large, the description thereof is omitted.

  When the use of the printing paper 1 is advanced and the roll diameter of the roll paper 5 is reduced and the light shielding portion 300a of the roll diameter detection lever 300 is between the light emitting element and the light receiving element of the sensor 340B, the sensor 340B outputs an off signal. Output. When the signal output from the sensor 340B is an off signal, the control device (not shown) controls the motor 100 so that the paper discharge roller 240 is positioned at the position shown in FIG. Specifically, the motor 100 is controlled, the curl correction cam 160 is rotated, and the first lever 170 is rotated in the direction of arrow B in FIG. When the first lever 170 is rotated in the direction of arrow B, the second lever 180 is rotated in the direction of arrow D in FIG. 2, and the paper discharge roller 240 supported by the second lever 180 is It is moved to the position shown in.

  Next, the control device controls the platen roller 40 to separate the printing paper 1 and the ink ribbon from the thermal head 50, and then rotates the supply shaft 10, the main feed roller 30, and the paper discharge roller 240. Then, the printed printing paper 1 is conveyed in the direction of arrow C in FIG. When the printing paper 1 is conveyed in the direction of arrow C in FIG. 1, the printing paper 1 with the curl is bent by the paper discharge roller 240 and the third paper guide 260 to have a curvature larger than the curvature shown in FIG. 8. At the same time, it is bent in the direction opposite to the curl and led to the paper discharge port. When the control device transports the printing paper 1 having a predetermined length, the control device controls the cutter 80 to cut the printing paper 1. When the printing paper 1 is cut, the control device rotates the paper discharge roller 240 to discharge the cut printing paper 1 from the paper discharge port cover 90.

As described above, according to the present embodiment, it is possible to adjust the degree of correction of the roll paper curl according to the winding diameter of the supply roll that supplies the roll paper.
Moreover, according to this embodiment, the following effects can be obtained. When the printing paper 1 is conveyed in the direction of arrow D in FIG. 1 and printing is performed, if the roll paper is bent by the paper discharge roller 240 and the third paper guide, the printing paper 1 is removed from the paper discharge roller 240. When it comes off, the force acting on the printing paper 1 varies. If the force acting on the printing paper 1 fluctuates during printing, the conveyance accuracy of the printing paper 1 decreases, and printing defects such as streaks appear in the printed image. In the present embodiment, the paper discharge roller 240 is separated from the third paper guide 260 during printing, so that printing can be performed without causing such a problem.

[C. Modified example]
The present invention is not limited to such an embodiment. Hereinafter, modifications of the above-described embodiment will be described.
(Modification 1)
Depending on the type of paper, the printing apparatus may change the degree of curvature of the printing paper 1 by changing the distance between the paper discharge roller 240 and the third paper guide even if the winding diameter of the roll paper is the same. Good. In addition, the printing apparatus receives information indicating the paper type, and controls the motor 100 according to the paper type indicated by the received information and the roll diameter of the roll paper detected by the sensors 340A and 340B. The degree of curvature of the printing paper 1 may be changed by changing the distance between the paper discharge roller 240 and the third paper guide. According to such an aspect, even when different types of paper are loaded, it is possible to correct the roll paper curl.

(Modification 2)
In the above-described embodiment, the winding diameter of the roll paper 5 is detected using a transmission type photosensor, but the method of detecting the winding diameter of the roll paper 5 is limited to the method of the above-described embodiment. Is not to be done. For example, the angle of the roll diameter detection lever 300 may be detected using an angle sensor, and the distance between the paper discharge roller 240 and the third paper guide 260 may be controlled according to the obtained angle.
(Modification 3)
The cross-sectional shape of the groove formed in the third paper guide is not limited to a semicircular shape, and may be, for example, a concave shape.
(Modification 4)
In the embodiment described above, the position of the paper discharge roller 240 is controlled to control the degree of curvature of the printing paper 1, but the position of the third paper guide 260 is controlled to control the degree of bending of the printing paper 1. You may do it.

1 is a diagram illustrating a configuration of a printing apparatus according to an embodiment of the invention. It is a figure which illustrates the structure of the curl correction mechanism concerning the embodiment. It is a figure which illustrates the structure of the curl correction mechanism concerning the embodiment. It is a figure for demonstrating the motion of the same curl correction mechanism. It is a figure for demonstrating the motion of the same curl correction mechanism. It is a figure which illustrates the structure of the roll diameter detection mechanism concerning the embodiment. FIG. 6 is a diagram illustrating a positional relationship between a paper discharge roller, roll paper, and a third paper guide. FIG. 6 is a diagram illustrating a positional relationship between a paper discharge roller, roll paper, and a third paper guide. FIG. 6 is a diagram illustrating a positional relationship between a paper discharge roller, roll paper, and a third paper guide.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printing paper, 5 ... Roll paper, 10 ... Supply shaft, 20 ... Guide roller, 30 ... Main feed roller, 40 ... Platen roller, 50 ... Thermal head, 60 ... feed roller, 70 ... first paper guide, 80 ... cutter, 90 ... discharge cover, 100 ... motor, 110 ... encode plate, 115 ... sensor, 120 ... Worm gear, 130 ... First gear, 140 ... Second gear, 150 ... Curl correction cam drive shaft, 160 ... Curl correction cam, 170 ... First lever, 175 ··· Supporting part, 180 ... second lever, 190 ... third lever, 200 ... fourth lever, 210 ... first idle gear, 220 ... second idle gear, 230・ Gear, 240 .. discharge roller, 250... Second paper guide, 260... Third paper guide, 270... First lever support shaft, 280A, 280B, 280C. 300 ... roll diameter detection lever, 300a ... light-shielding part, 310 ... support shaft, 320 ... roller, 330 ... pin, 340A, 340B ... sensor.

Claims (2)

A feeding means for rotating roll paper made of printing paper wound around a supply shaft and feeding out the printing paper;
Detection means for detecting the roll diameter of the roll paper;
The printing paper is fed downstream from the supply shaft , located downstream of the printing paper conveyance direction as viewed from the printing unit for printing on the printing paper, upstream of the printing paper conveyance direction as seen from the paper discharge port . A roller for conveying printing paper;
A groove extending in a direction parallel to the rotation axis of the roller, sandwiching the printing paper between the rollers, facing the roller, and recessed to receive the roller, and an edge of the groove from the edge of the printing paper A paper guide having a plate-like portion that protrudes upstream in the conveying direction and guides the printing paper to the groove;
When printing paper fed out from the supply shaft and positioned downstream in the transport direction from the roller is sent to a printing unit upstream in the transport direction from the roller, printing is performed. Control the relative distance between the roller and the groove of the paper guide so that it does not hit the edge of the paper guide groove, and after the printing on the printing paper is finished, the printed printing paper is Control means for curving the printing paper in a direction that eliminates curling caused by being wound around the supply shaft by being pushed toward the groove of the paper guide by the roller while being fed downstream in the conveying direction. And
The printing device according to claim 1, wherein the control unit controls a relative distance between the roller and the groove of the paper guide in accordance with a winding diameter detected by the detection unit . The printing apparatus according to claim 1, wherein the control unit varies a position of the roller according to a type of the printing paper.

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