KR101495592B1 - Card printer with tensioning device for printing-ribbon - Google Patents

Abstract

The present invention relates to a card printer having an apparatus for automatically adjusting tension of a ribbon, and more specifically, to a card printer having an apparatus for automatically adjusting tension of a ribbon which enables a printing ribbon wound around a supply roll to execute printing operation in a card printer to be moved toward a winding roll while always being under uniform tension, thereby improving printing quality. According to the present invention, a card printer having an apparatus for automatically adjusting tension of a ribbon includes a printing ribbon device having a supply roll on which a printing ribbon wound in a shape of a roll is installed and a winding roll having the printing ribbon wound after being unwound and passing a thermal transfer head; a printing ribbon operation device rotating the winding roll or the supply roll to move the printing ribbon; a printing ribbon thickness detection unit installed by contacting the supply roll to detect the thickness of the printing ribbon wound around the supply roll; and a torque adjusting unit disposed between the printing ribbon thickness detection unit and the supply roll, and adjusting rotary torque of the supply roll in accordance with the thickness of the printing ribbon detected by the printing ribbon thickness detection unit. According to the present invention, tension applied to the printing ribbon is always the same even if the winding roll is rotated by the same force in a case wherein great amount of printing ribbon is wound around the supply roll and a case wherein small amount of printing ribbon is wound around the supply roll, such that printing quality of a printing layer on which a surface of a card is printed when passing the thermal transfer head is improved.

Description

CARD PRINTER WITH TENSIONING DEVICE FOR PRINTING-RIBBON WITH AUTOMATIC RIBBON TENSIONING UNIT

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a card printer having an automatic ribbon tension adjusting device, and more particularly, to a card printer having an automatic ribbon tension adjusting device, The present invention relates to a card printer having an automatic ribbon tension adjusting device capable of improving printing quality by allowing a user to move the card to a predetermined position.

Generally, a card printer is a device for printing data on a surface of various cards such as a personal identification card, an identification card, and an employee card by receiving data from a computer. In the printing process of the card, when the card is supplied from the card supply device, the thermal print head is driven in a state in which the print ribbon is positioned on the printed surface of the card to perform the printing operation.

The printing ribbon 40 is unwound by the printing ribbon driving device in a state of being wound on the feeding roll 50 as shown in Fig. 1, guided and moved to the guide rollers, It is to be rewound.

The printed ribbon driving device is driven by the belt 213 by driving the lower DC motor 211 as shown in the Korean Utility Model Registration No. 20-0277605 (registered on May 27, 2002) As the connected winding roll 212 is rotated, the printing ribbon 216 is pulled from the feeding roll 214 and fed along the guide roller 215 to perform the printing process. When the rolled-off printing ribbons of the supply roll 214 are sequentially released through the printing process and are all used, the printing process is repeatedly performed by replacing with the new product.

However, in the conventional card printer described above, since the load device constituted on the supply roll axis for giving tension to the print ribbon is fixed, a large amount of the print ribbon is wound on the supply roll, and a state where a small amount of the print ribbon is wound on the supply roll There is a limit in that the printing quality is deteriorated due to differences in the tension applied to the printing ribbon.

More specifically, if the thermal transfer head 228 is lowered to press the printing ribbon 216 in the card direction while a thermal transfer operation is being performed, if the tension of the transferred printing ribbon changes, printing There is a problem that a uniformity of the image quality and resolution are significantly different.

SUMMARY OF THE INVENTION The present invention provides a card printer having an automatic ribbon tension adjusting device for improving printing quality by causing a printing ribbon wound on a supply roll to always move in a state in which a uniform tension is applied It has its purpose.

In order to achieve the above object, a card printer provided with an automatic ribbon tension adjusting device according to the present invention is a card printer comprising a supply roll provided with a print ribbon wound in a roll form, A printing ribbon device with a roll; A print ribbon thickness sensing unit including a print ribbon driving device for rotating the take-up roll or the supply roll to move the print ribbon, the print ribbon thickness sensing unit being installed in contact with the supply roll to sense the thickness of the print ribbon wound on the supply roll; And a torque adjusting unit which is disposed between the printing ribbon thickness sensing unit and the supplying roll and adjusts the rotation torque of the supplying roll according to the thickness of the printing ribbon sensed by the printing ribbon thickness sensing unit.

The print ribbon thickness sensing portion may include a contact member which is in contact with the print ribbon wound on the supply roll, and a connection shaft which is connected to the contact member and is rotatably connected to the frame.

The torque adjusting unit includes a cam member inserted into the supply roll driving shaft and coupled with the connecting shaft so as to be inserted into the supply roll driving shaft to which the supplying roll is installed, an elastic force that is changed while being contracted and expanded in accordance with angular movement of the cam member And an elastic member for adjusting a rotational torque applied to the supply roll by the elastic member.

The cam member includes a cam plate to which the connecting shaft is coupled at one end, a guide slot penetrating through the other side of the cam plate and inserted with the supply roll driving shaft, And a cam follower portion formed to be increased from the lower portion toward the lower portion.

Meanwhile, the automatic ribbon tension adjusting device according to the present invention includes: a drive bushing movably inserted into the supply roll drive shaft and closely attached to the cam protrusion; And a torsion spring inserted into the connection shaft and having one free end fixed to the cam plate and the other free end fixed to the frame.

The print ribbon driving device includes a supply roll driving gear which is rotated by receiving a rotational force from a driving motor and is mounted on the supply roll driving shaft, and the elastic member is provided between the driving bush and the supply roll driving gear, And a compression coil spring installed on the supply roll drive shaft.

According to the card printer having the automatic ribbon tension adjusting device according to the present invention, when a large amount of the print ribbon is wound on the supply roll and a small amount of the print ribbon is wound on the supply roll, The printing quality of the printing layer printed on the surface of the card during the passage of the thermal transfer head is improved because the tension applied to the printing ribbon is always the same.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining a printing ribbon driving method of a general card printer;
2 is a view for explaining a printing ribbon driving apparatus of a conventional card printer,
3 is a perspective view showing a card printer having an automatic ribbon tension adjusting device according to an embodiment of the present invention,
4 is a perspective view showing a part of a card printer having an automatic ribbon tension adjusting device according to an embodiment of the present invention,
Fig. 5A is a perspective view showing a main portion of a card printer having an automatic ribbon tension adjusting device according to an embodiment of the present invention, Fig.
5B is a perspective view showing a cam member of a card printer equipped with an automatic ribbon tension adjusting device according to an embodiment of the present invention,
6A and 6B are diagrams for explaining the operation of the card printer having the automatic ribbon tension adjusting device according to the embodiment of the present invention. And FIG. 6B is a perspective view showing an operating state in a state in which the thickness of the print ribbon is reduced on the supply roll.

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

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an automatic ribbon tension adjusting device and, more particularly, to be.

3 and 4, a card printer having an automatic ribbon tension adjusting device according to an embodiment of the present invention includes a frame 1, a printing ribbon a ) And a take-up roll (3) in which the print ribbon is unrolled and passed through a thermal transfer head (b, shown by imaginary lines in Fig. 3) And a printing ribbon driving device (4) for moving the printing ribbon (a) by rotating the roll (3) so as to keep the tension of the printing ribbon moved by the printing ribbon driving device (4) And an adjusting device 5 is further provided.

The automatic ribbon tension adjusting device 5 includes a printing ribbon thickness sensing portion 51 for sensing the thickness of the printing ribbon a wound on the supply roll 2, And a torque adjusting unit 52 for adjusting the rotation torque of the supply roll 2 according to the thickness of the supply roll 2 so that a constant tension is always applied to the print ribbon.

FIG. 5A is a perspective view showing a main part of a card printer equipped with an automatic ribbon tension adjusting device according to an embodiment of the present invention, FIG. 5B is a perspective view showing a cam member of a card printer having an automatic ribbon tension adjusting device according to an embodiment of the present invention Fig.

3 to 5B, the printing ribbon thickness sensing portion 51 is provided in contact with the supply roll 2 and includes a contact member 511 in contact with the printing ribbon a wound on the supply roll 2 And a connecting shaft 512 which is connected to one side of the contact member 511 and is rotatably connected to the frame 1 is provided.

The contact member 511 includes a contact roller 511a contacting the surface of the print ribbon wound around the supply roll 2, a contact roller rotational shaft 511b inserted into the center of the contact roller 511a, And a bearing bracket 511c having a bearing groove in which the lower portion is coupled and in which the contact roller rotation shaft 511b is inserted.

The connecting shaft 512 is formed in the shape of a round bar, and one side portion is coupled to the rotating bracket 511c, and the other side portion is coupled to a cam plate to be described later.

The torque adjusting section 52 is disposed between the printing ribbon thickness sensing section 51 and the supply roll 2 and includes a cam member 521 interlocked with the connecting shaft 512, And an elastic member 522 for adjusting the rotational load of the supply roll 2 by an elastic force which is changed while being contracted and expanded during exercise.

The cam member 521 is a member in which one end of the cam member 521 is coupled to the connection shaft 512 and the other end of which is connected to the supply roll drive shaft 41, And a guide elongated hole 521b and a cam protrusion 521c are formed on the formed cam plate 521a.

5B, the cam plate 521a is formed with a shaft insertion hole to which a connecting shaft 512 is coupled at one end of a body formed in a plate shape, and a latching piece 521d is protruded at the other end. Here, the engaging piece 521d is a portion to which a cam operating member (not shown) for lifting the cam member 521 upward to rotate is connected. This cam operating member (not shown) So that the contact member 511 engaged via the connection shaft 512 is opened outwardly from the supply roll 2 so as to secure a working space at the time of replacement of the supply roll 2.

 The guide elongated hole 521b penetrates the other side of the cam plate 521a in an arc shape, and the supply roll driving shaft 41 is inserted.

The cam protrusion 521c protrudes in contact with the guide elongated hole 521b, and the protrusion height is gradually increased from the top to the bottom.

The elastic member 522 is inserted into the supply roll drive shaft 41 and contracts and expands according to the angular movement of the cam member 52 and is inserted between the drive bushing 523 and a feed roll drive gear 468 And a compression coil spring. At this time, the elastic member 522 is installed in close contact with the contact washer coupled to the side surface of the feed roll drive gear.

A drive bushing 523 having a substantially disk shape is inserted into the supply roll drive shaft 41 so as to be in close contact with the cam surface of the cam protrusion 521c. The drive bushing 523 is moved back and forth in a state of being inserted into the supply roller drive shaft in accordance with the protruding height of the cam follower portion during angular movement of the cam plate 521a in a state of being mounted on the cam surface of the cam protrusion 521c.

On the other hand, the automatic ribbon tension adjusting device 5 is further provided with a torsion spring 53 for improving the stability of the operation of the printing ribbon thickness sensing portion 51 and the torque adjusting portion 52. The center winding portion of the torsion spring 53 is inserted into the connecting shaft 512, one free end thereof is fixed to the cam plate 521a, and the other free end thereof is fixed to the frame 1.

The torsion spring 53 is compressed according to the operation of the cam member 52 which is rotated upward when the thickness of the printing ribbon (a) is thick, so that the elastic force is stored and conversely, the torsion spring 53 is gradually expanded And the cam member 52 is stably operated in response to the movement of the contact member 511 while stably touching the print ribbon a wound on the supply roll 2 by applying an elastic force to the contact roller 511a Function.

6A and 6B are diagrams for explaining the operation of the card printer having the automatic ribbon tension adjusting device according to the embodiment of the present invention. And FIG. 6B is a perspective view showing an operating state in a state in which the thickness of the print ribbon is reduced on the supply roll.

The printing ribbon driving device 4 may be configured with various driving mechanisms without any particular limitation as long as the printing ribbon a can be moved in the forward and reverse directions. However, in this embodiment, as shown in Fig. 6A, And power transmission means 46 composed of a plurality of pulleys and gears. The power transmission means 6 includes a drive pulley 461 coupled to the motor shaft of the drive motor 45, an electric pulley 463 connected to the drive pulley 461 via a belt 462, an electric pulley 463, A first idle gear 465 engaged with the transmission gear 464 and a second idle gear 465 meshed with the first idle gear 465 and fixed to the take-up roll drive shaft 43. The take-up roll driving gear 466 is connected to the take-up roll driving gear 466. [

The print ribbon driving device 4 includes a second idle gear 467 engaged with the transmission gear 464 so as to rotate the supply roll 2 and a second idle gear 467 engaged with the second idle gear 467, And a supply roll drive gear 468 coupled to the drive shaft 41 is provided.

The winding roll drive shaft 43 and the supply roll drive shaft 41 are rotatably mounted on a frame or the like by a bearing (not shown), and a winding roll 3 is provided at a portion where the winding roll 3 and the supply roll 2 are installed. (Not shown) and a supply roll connection cone 42 are provided for stable mounting of the supply roll 2 and the supply roll 2, respectively.

The first idle gear 465 and the second idle gear 467 are rotatably coupled to one side and the other side of the hinge plate 469. The first idle gear 465 is coupled to the driving motor 45, The gears are meshed with the transmission gear 464 in the forward rotation of the take-up roll 464 and are moved toward the take-up roll drive gear 466 and are engaged with each other. The second idle gear 467 is engaged with the transmission gear 464 and moved to the side of the supply roll drive gear 468 so that the supply roll 2 is engaged with the take- The drive shaft 41 is rotated.

When the drive motor 45 is operated, the above-described print ribbon driving device 4 drives the drive pulley 461, the belt 462, the electric pulley 463, the transmission gear 464, the first idle gear 465, And the take-up roll driving gear 466 are rotated in this order, the take-up roll 3 is rotated, so that the print ribbon a wound on the supply roll 2 is pulled and released. Thereafter, the printing ribbon (a) passes through the thermal transfer head (b) and is wound on the winding roll (3).

In this printing process, since the ink layer formed on the printing ribbon (a) always starts to move at a predetermined position, the desired color can be accurately printed, so that the printing ribbon driving device moves the printing ribbon every printing, It is necessary to start the printing process after aligning the starting point of the first stage to be positioned on the entry side of the thermal transfer head b. At this time, the second idle gear 467 engaged with the transmission gear 464 rotated in the reverse direction under the control of the control unit (not shown) and rotated in the opposite direction is moved to the side of the supply roll drive gear 468 The supply roller driving shaft 41 is rotated and the print ribbon a is pulled toward the supply roll 2 in the reverse direction and is moved back to the entry side portion of the thermal transfer head b and aligned.

4, reference numerals 71 and 72 denote a normal encoder wheel and an encoder optical sensor. The encoder optical sensor 72 senses the release or retract distance of the print ribbon a from the encoder wheel 71 to be rotated And a predetermined control operation is performed by applying a detection signal to the control unit.

Hereinafter, the operation of the card printer having the automatic ribbon tension adjusting device according to the embodiment of the present invention will be briefly described.

First, as shown in Fig. 6A, in a state where a supply roll 2 having a large number of print ribbon (a) wound thereon is provided in a supply roll connection cone 42 of a supply roll drive shaft 41, The rotational force is transmitted in the order of the drive pulley 461, the belt 462, the electric pulley 463, the transmission gear 464, the first idle gear 465 and the take-up roll drive gear 466, The printing ribbon 3 wound on the supply roll 2 is pulled and moved. At this time, the contact roller 511a is in an outwardly open state due to the thick thickness of the print ribbon, and the contact member 511 to which the contact roller 511a is coupled rotates in the clockwise direction And the connecting shaft 512 engaged with the contact member 511 is interlocked so that the cam member 52 is rotated in the clockwise direction in the same direction with respect to the connecting shaft as shown in FIG. 6A .

When the cam member 52 is rotated in the clockwise direction as described above, the position of the cam protrusion 521c formed on the other side of the cam plate 521a also angularly moves upward as shown in Fig. 5A, so that the cam protrusion 521c is seated The driving bushing 523 is positioned at the highest point of the camel portion (the portion where the protruding height of the camel portion is relatively large). As a result, the gap between the drive bushing 523 and the supply roll driving gear 468 becomes narrow and the elastic member 522 interposed therebetween is compressed, so that a large elastic force is applied to the supply roll driving gear 468 to apply an urging force . This pressing force acts as a frictional load that is resistant to the rotational force of the supply roll drive gear 468 and this friction load is transmitted to the supply roll drive shaft 41 to which the supply roll drive gear 468 is coupled, A relatively large rotational torque is applied to the feed roll 2 coupled to the feed roll 2 due to the frictional load.

When the thickness of the printing ribbon (a) wound on the supply roll (2) gradually decreases by performing the printing operation repeatedly in this state, the rotational torque applied to the supply roll (2) And gradually decreases due to the action of the torque adjusting unit 52. More specifically, as shown in FIG. 6B, the contact member 511 including the contact roller 511a is rotated counterclockwise (in the direction of the reference in FIG. 6B) As the connecting shaft 512 engaged with the contact member 511 is interlocked, the cam member 52 is rotated counterclockwise in the same direction with respect to the connecting shaft.

When the cam member 52 is rotated in the counterclockwise direction as described above, the position of the cam protrusion 521c formed on the other side of the cam plate 521a is also angularly moved downward. Therefore, the driving bushing 523 seated on the cam protrusion 521c The position is moved to the low point position of the camel portion (the portion where the protrusion height of the cam portion is low) so that the distance between the drive bushing 523 and the supply roll drive gear 468 is widened and the elastic member 522 interposed therebetween is expanded The elastic repulsive force applied to the supply roll driving gear 468 is gradually reduced.

The frictional load exerted on the feed roll drive gear 468 is reduced and the feed roll drive shaft 41 coupled to this feed roll drive gear 468 is also reduced in friction torque, Is gradually decreased.

As described above, according to the automatic ribbon tension adjusting apparatus of the present invention, when the lamination thickness of the print ribbon (a) wound on the supply roll 2 is large, the rotational torque applied to the supply roll 2 becomes large, It can be seen that the rotational torque acting on the feed roll 2 also gradually decreases when the lamination thickness of the ribbon (a) is gradually reduced. In other words, when the lamination thickness of the printing ribbon (a) is large (the radius of the feeding roll is large), the rotational torque acting on the feeding roll is large and the lamination thickness is decreased (the radius of the feeding roll is gradually decreased) Even if the diameter of the supply roll including the print ribbon is changed, as can be seen from the formula (T = F (Kgf, force) x (radius)) of the torque T The print ribbon can be pulled with the same force, that is, the same tension. Even if the driving motor 45 always rotates the winding roll 3 with the same force, the tension applied to the printing ribbon a becomes the same, so that the image quality printed on the surface of the card c at the time of passing through the thermal transfer head And the resolution and the uniformity of the image are improved.

Although the present invention has been described in connection with what is presently considered to be preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

And the terminology used in the foregoing embodiments is used only to describe a specific embodiment and is not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

a: print ribbon b: thermal transfer head
c: Card 1: Frame
2: feed roll 3: winding roll
4: Print ribbon drive device 41: Feed roll drive shaft
43: Winding roll drive shaft 45: Drive motor
46: Power transmission means 461: Driving pulley
462: Belt 463: Electric pulley
464: transmission gear 465: first idle gear
466: Winding roll drive gear 467: Second idle gear
468: Feed roll driving gear 5: Automatic ribbon tension adjusting device
51: Printing ribbon thickness sensing part 511: Contact member
511a: contact roller 511b: contact roller shaft
511c: Rotation bracket 512: Connection axis
52: Torque adjusting portion 521: Cam member
521a: cam plate 521b: guide slot
521c: cam protrusion 522: elastic member
523: drive bushing 53: torsion spring

Claims (5)

A printing ribbon device having a supply roll on which a print ribbon wound in a roll form is installed and a take-up roll on which the print ribbon is unwound and wound after passing through the thermal print head; A printing ribbon driving device for rotating the winding roll or the feeding roll to move the printing ribbon; A print ribbon thickness sensing portion mounted adjacent to the supply roll to sense the thickness of the print ribbon wound on the supply roll; And a torque adjustment unit disposed between the print ribbon thickness sensing unit and the supply roll and adjusting a rotation torque of the supply roll according to a thickness of the print ribbon sensed by the print ribbon thickness sensing unit,
Wherein the print ribbon thickness sensing portion includes a contact member which is in contact with the print ribbon wound on the supply roll and a connection shaft which is connected to one side of the contact member and is rotatably connected to a frame on which the print ribbon device is mounted,
The torque adjusting unit includes a cam member inserted into the supply roll driving shaft and coupled with the connecting shaft so as to be inserted into the supply roll driving shaft to which the supplying roll is installed, an elastic force that is changed while being contracted and expanded in accordance with angular movement of the cam member And an elastic member for adjusting a rotational torque applied to the supply roll by the elastic member.
delete The method according to claim 1,
The cam member includes a cam plate to which the connecting shaft is coupled at one end, a guide slot penetrating through the other side of the cam plate in a arc shape and inserted with the supply roll driving shaft, And a cam follower portion that is formed to be gradually increased toward the main body of the card printer.
The method of claim 3,
A drive bushing movably inserted into the supply roll drive shaft and brought into close contact with the cam protrusion; And
And a torsion spring inserted into the connection shaft and having one free end fixed to the cam plate and the other free end fixed to the frame.
5. The method of claim 4,
Wherein the print ribbon driving device includes a supply roll driving gear that is rotated by receiving a rotational force from a driving motor and is mounted on the supply roll driving shaft,
Wherein the elastic member is composed of a compression coil spring provided on the supply roller drive shaft between the drive bushing and the supply roll drive gear.

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