JPH03159779A - Ink ribbon take-up device of printer - Google Patents

Abstract

PURPOSE:To enable always giving a constant tension to an ink ribbon through only one wind-up roller by equipping the wind-up roller pressure-welded to the outer peripheral face of a take-up reel and rotated with a constant torque in the take-up direction of the ink ribbon through driving of a take-up motor and an energizing means for energizing and pressure-welding the wind-up roller to the outer peripheral face of the take-up reel through a predetermined pressure welding force. CONSTITUTION:A take-up reel 15 is rotated by a torque weaker than that of a wind up roller 32. The wind-up roller 32 is energized in the direction of the take-up reel 15 via link plate 31 by an energizing means 40 composed of an extension spring and always pressed against the outer peripheral face of the take-up reel through a predetermined pressure. One end of the extension spring 40 is fitted to a fitting piece 310 provided in the middle of the link plate 31 and the other end, to a fitting piece 311 on the printer body side to always energize the wind-up roller 32 via the link plate 31 in the direction of pressure- welding to the outer peripheral face of the take-up reel 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ink ribbon winding device suitable for application to a high-quality thermal transfer printer such as a full color video printer.

Conventional technology In a thermal transfer printer using a thermal head, a supply reel and a take-up reel of ink ribbon are arranged through a platen, and the head is pressed against the paper wound around the platen through the ink ribbon, thereby printing the paper together. Printing is performed by heating the heel while feeding the ink ribbon to the winding side.

Among these types of printers, a take-up reel is rotated by the drive of a take-up motor, and the rotation of the take-up reel directly applies a tensile force in the winding direction to the ink ribbon to wind it. There is. However, if the tension force for winding the ink ribbon is directly applied to the ink ribbon by the rotation of the take-up reel, when the ribbon winding diameter of the take-up reel changes in size, the tensile force for winding the ink ribbon is adjusted accordingly. For example, when the printer is a high-level thermal transfer printer, high image quality cannot be expected as a result.

Therefore, in thermal transfer printers for high image quality, etc., a take-up roller and a vinch roller are arranged facing each other on the ink ribbon take-up path in front of the platen, and the ink ribbon pressed between them is kept at a constant tension TI. It is designed to be rolled up. In this case, the tension in the winding direction given to the ink ribbon by the take-up roller is always kept constant because the diameter of the take-up roller is constant.

FIG. 4 shows the main parts of a thermal transfer printer using a conventional thermal head.

In FIG. 4, a platen 10 is rotatably supported in the printer main body in the paper feeding direction. During printing, the paper A is wrapped around the circumferential surface of the platen 10 and is sequentially sent from the supply side to the delivery side. A paper feed roller 11 is disposed on the paper feed side in front of the platen 10. A Vinci roller 12 is disposed adjacent to the paper feed roller 1l so as to be able to be pressed into contact with it and detached from it. Printing During printing, the pinch roller 12 pinches the paper A and comes into pressure contact with the paper feed roller 11, and is rotated in the paper feed direction along with the rotation of the paper feed roller 11. The paper feed roller 11 is rotationally driven by a driving means 13 such as a stepping motor, and sequentially feeds the paper A sandwiched between it and the pinch roller 12 in steps in the sending direction. Following the rotation of the paper feed roller 11, the platen 10 rotates in the same direction, and the paper A is fed in steps with the rotation. Printing●During the printing operation,
Ink ribbon B is attached to platen 10 via paper A, and is synchronized with paper A in the same direction.

A supply reel 14 and a take-up reel 15 of an ink ribbon cassette are arranged with their axes parallel to each other on one side of the ribbon B supply side and the other side of the ribbon B take-up side via the platen 10. . The ink ribbon B is wound around the supply reel 14 and the take-up reel 15, and is sequentially fed out from the supply reel 14 toward the take-up reel 15 and wound up.

The supply reel 14 and the take-up reel i5 have the bobbin 1 at the center.
4L151, and these bobbins 141, 151
The ends of the ink ribbon B are fixed to the respective ends.

An ink ribbon winding mechanism is arranged in front of the platen 10.

An ink ribbon take-up motor 16 is located near the take-up reel 15.
is located. On the other hand, a take-up roller 17 that applies a tensile force to the ink ribbon B is disposed on the ribbon take-up path in front of the platen 10b.

A pinch roller 18 is pressed against and separated from the take-up roller 17 via the ribbon B. Take-up motor 16 and take-up roller 1
7 is connected by a belt transmission mechanism. That is, the belt 20 is stretched between the drive shaft of the take-up motor 16 and the friction clutch 19.
A belt 21 is stretched between the winding roller 17 and the shaft of the winding roller 17.

The driving force of the take-up motor 16 is transmitted to the take-up roller 17 via the belt 20, the friction quatch 19, and the belt 21.
It is rotated in the winding direction. At this time, the torque transmitted to the take-up roller 17 is kept constant by the friction clutch 19.

Further, the take-up motor 16 and the take-up reel l5 are connected by a belt transmission mechanism. That is, a friction clutch 22 is interposed between the take-up motor 1B and the take-up reel 15, and the belt 2 is interposed between the take-up motor 16 and the friction clutch 22 and between the friction clutch 22 and the take-up reel 15.
3 and a belt 24, and the rotational power of the take-up motor 16 is transmitted to the take-up reel 15 via a belt transmission mechanism made up of these members. The tension in the winding direction given to the ink ribbon B by the rotation of the take-up reel 15 is smaller than the tension TI in the winding direction given to the ink ribbon B by the take-up roller 17, TI>T2, and the winding When the ink ribbon B is wound around the handle 15, wrinkles may occur on the ink ribbon B,
The size is large enough to prevent the occurrence of sagging.

The take-up reel 15 is connected to the belt transmission mechanism described above when the ink ribbon cassette is set in the printer, and is connected to the take-up motor 16 via this belt transmission mechanism.

The thermal head 25 is pressed against the platen 10 via the paper A and the ink ribbon B by the drive of the head drive mechanism 26 during the printing operation.

Then, along with the feeding operation of paper A and ink ribbon B, printing is performed on the thermal head 25. A voltage corresponding to the printing information is applied in the form of a pulse, and printing is performed on paper A by thermal transfer of ink.
A print is made.

The thermal head 25 moves in a direction in which it comes into pressure contact with the platen 10 or separates from the platen 10 via the paper A1 and the ink ribbon B, by the operation of the head drive mechanism 26. At this time, the pinch roller 18 moves in the same direction together with the thermanole head 25, and comes into pressure contact with the ink ribbon B on the winding path -L, or separates from it.

Problems to be Solved by the Invention Conventional thermal transfer printers that pursue high image quality have to maintain constant tension (tensile force) in the winding direction on the ink ribbon B by using a platen, a ribbon between the thermal head and the take-up reel. It was necessary to provide a pinch roller in addition to the take-up roller on the take-up path.

As a result, the ink ribbon winding mechanism becomes complicated and the space occupied increases, resulting in a problem that the mechanism of the printer becomes larger.

This invention eliminates the pinch roller for taking up the ribbon on the ink ribbon take-up path, thereby simplifying and making the mechanism more compact. ).

Means for Solving the Problems In order to achieve the above object, the first technical means of the present invention is to apply pressure to the outer peripheral surface of the take-up reel and apply a constant torque in the winding direction of the ink ribbon by driving a take-up motor. The present invention is characterized by comprising a take-up roller which is rotated by the winding reel, and a biasing means which urges and presses the take-up roller against the outer circumferential surface of the take-up reel with a predetermined pressure contact force.

A second technical means of the present invention includes a take-up roller that is pressed against the outer peripheral surface of the take-up reel and rotated with a constant torque in the winding direction of the ink ribbon by the drive of a take-up motor; A link that rotatably supports the take-up motor around the drive shaft, a power transmission means that transmits the driving force of the take-up motor to the take-up roller at a constant torque, and rotates the take-up roller in the ribbon winding direction; The present invention adopts a configuration including a biasing means for urging the take-up roller to press against the outer circumferential surface of the take-up reel at a predetermined pressure. In this case, the power transmission means is configured with a winding transmission mechanism, and a friction clutch is interposed in the winding transmission mechanism to keep the torque transmitted to the take-up roller constant, or the power transmission means is configured with a gear mechanism. The gear mechanism is a reduction gear train that keeps the torque transmitted to the take-up roller constant. This is also within the scope of the present invention.

Furthermore, in each of the above technical means, the biasing means is constituted by a tension spring, and the spring pressure of the tension spring is adjusted within a range where the ribbon winding diameter of the take-up reel changes in size, and the pressure contact force of the take-up roller is within a predetermined pressure range. It is also included in the technical feature of the present invention that it is set so that

Function: When an ink ribbon cassette is loaded into a printer, a take-up roller is pressed against the outer peripheral surface of the take-up reel with a constant rotational torque, and is rotated in the ribbon winding direction with a constant transmitted torque by the drive of the take-up motor. . The take-up roller is rotated by being pressed against the outer peripheral surface of the reel with a constant torque by a predetermined biasing force of the biasing means and a constant transmission torque from the power transmission mechanism, so that the ink ribbon is always kept in a constant winding direction. Tension TI can be applied. That is,
Even if the ribbon winding diameter of the take-up reel changes in size, the torque transmitted from the power transmission mechanism remains constant, and the take-up roller is constantly applied to the outer peripheral surface of the take-up reel with a constant torque due to the urging force of the urging means. Since the ink ribbon is pressed, a constant tension TI can always be applied to the ink ribbon regardless of changes in the ribbon winding diameter of the take-up reel.

If the biasing means is composed of a tension spring, when the ribbon winding diameter of the take-up reel changes in size, the tension spring will expand and shorten according to the change in the ribbon winding diameter, and within the range of the expansion and shortening. A biasing force of spring pressure is applied to the take-up roller according to the change in the ribbon winding diameter.

As a result, the take-up roller is pressed against the outer peripheral surface of the reel with a constant transmitted torque regardless of changes in the ribbon winding diameter of the take-up reel, and the pressing force remains at a constant pressure in accordance with changes in the ribbon winding diameter. be adjusted. This results in
The tension e applied to the ink ribbon is always kept constant without being affected by changes in the ribbon winding diameter.

As described above, the tension in the winding direction applied to the ink ribbon can be kept constant at all times using only the winding roller.

Therefore, the vinch roller, which was conventionally required in the ribbon winding path, becomes unnecessary, and it becomes possible to arrange the winding reel at that position or at a position near it. This makes it possible to reduce the number of component parts of the ink ribbon winding mechanism and save space.

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

1 and 2 show a first embodiment of the ink ribbon winding mechanism of a printer according to the present invention, and the same parts as in FIG. Omitted.

One end of a link plate 31 on the side of a support stand 30 that supports the take-up motor 16 is coaxially attached to the drive shaft l61 of the motor. A take-up roller 32 for the ink ribbon B is rotatably supported at the other end of the link plate 31. The take-up roller 32 is supported by the link plate 31 so as to be rotatable around a drive shaft 181 at one end thereof. The rotation locus of the center P of the take-up roller 32 coincides with the circumference passing through the center Q of the take-up reel 15. That is, the length OP connecting the drive shaft center 0 of the take-up motor 16 and the center P of the take-up roller 32 is equal to the length OQ connecting the drive shaft center C10 of the motor 16 and the center Q of the take-up reel 15. When the link plate 31 rotates around the drive shaft 161 of the motor 16, the rotation locus of the center P of the roller is the center Q of the take-up reel l5.
It passes on the circumference of radius OP passing through.

The drive shaft 181 of the take-up motor 16 and the shaft of the take-up roller 32 are connected by a belt transmission mechanism.

Pulleys 33 and 34 are attached to the drive shaft 161 of the motor 16 and the shaft of the take-up roller 32, respectively. A friction clutch 35 is interposed between the motor 16 and the take-up roller 32. A belt 36 is stretched between a pulley 33 of the drive shaft IE31 of the motor 16 and a pulley 351 of the friction clutch 35. In addition, the pulley 3 of the friction clutch 35
52 and the pulley 34 of the take-up roller 32
is being passed over. The rotational power of the take-up motor 16 is transmitted to the take-up roller 32 by these belt pulleys and friction clutches. From the motor 16 to the take-up roller 3
The torque transmitted to 2 is kept constant by a friction clutch 35. The length of the take-up roller 32 in the axial direction is set to be equal to or slightly longer than the width of the ink ribbon B.

On the other hand, a pulley 33 is attached to the drive shaft 161 of the winding motor 16.
A pulley 33゛ with the same diameter is attached. This pulley 33'' and the boot U 2 2 1 of the friction clutch 22
Belts 23, 24
are distributed between each.

When the ink ribbon is loaded into the printer, the bobbin 151 of the take-up reel 15 is coaxially connected to the bobbin 222 on the printer side. The take-up reel 15 is rotated in the ribbon winding direction by the drive of the take-up motor 16 via a belt transmission mechanism consisting of a belt pulley and a friction clutch. At this time, the take-up reel 15 is rotated with a rotation torque that is weaker than the rotation torque of the take-up roller 32. The tension T2 in the winding direction applied to the ink ribbon B by the winding roller 32 is set to be much smaller than the tension TI applied to the ink ribbon B by the take-up roller 32. .

The take-up roller 32 is urged in the direction of the take-up reel l5 via the link plate 31 by a biasing means 40 made of a tension spring, and is constantly pressed against its outer peripheral surface with a predetermined pressure.

One end of the tension spring 40 is attached to a mounting piece 310 provided in the middle of the link plate 31, and the other end is attached to a mounting piece 311 on the printer main body side, and the tension spring 40 is attached to the take-up roller 32 on the take-up reel 15.
It is constantly biased via the link plate 31 in a direction in which it comes into pressure contact with the outer circumferential surface of the link plate 31.

The ribbon winding diameter of the take-up reel 15 changes from time to time depending on the beginning of winding, the intermediate state, near the end of winding, and the like.

Therefore, the tension spring 40 is arranged so as to extend and shorten in response to changes in the ribbon winding diameter within the ranges of maximum, minimum extension, and shortening, and not to reach the maximum length and minimum shortening. The spring pressure is at the maximum ribbon winding diameter (near the end of the ribbon winding)
The ribbon winding diameter is Mmaxx'J when the ribbon is stretched to a minimum (at the beginning of winding) and Mmin is at the corresponding shortening time. The spring pressure of the tension spring 40 is set so that the tension spring 40 is pressed against the outer peripheral surface of the take-up reel 15 with a necessary and sufficient pressing force. Furthermore, the tension spring 4
If 0 is in the range of Mmax-Mmi ri,
゜The take-up roller 32 is urged against the outer circumferential surface of the take-up reel 15 with a substantially constant pressing force regardless of the size change in the ribbon winding diameter ●The spring pressure corresponds to the size change in the ribbon winding diameter so that it can be pressed into contact with the winding roller 32. It is set so that the pressing force of the take-up roller 32 against the outer circumferential surface of the reel is kept substantially constant during both expansion and contraction. Due to the biasing and pressing action of the tension spring 40 and the constant torque transmitted via the friction clutch 35 of the belt transmission mechanism, the take-up roller 32 is
The take-up reel 15 is in a state where a constant torque is always transmitted.
The ribbon is pressed against the winding surface of the ribbon and rotates. Due to this rotation, a constant tension T1 in the winding direction acts on the ink ribbon B at all times.

In the above configuration, as shown in FIG. 2, when the ribbon winding diameter of the take-up reel 15 is small at the beginning of winding the ink ribbon B, the tension spring 40 is shortened in accordance with the small winding diameter. Along with the shortening operation, the link plate 31 rotates around the drive shaft 161 of the motor 18 toward the take-up reel. As a result, the take-up roller 32 is applied to the take-up roll 15 with a substantially constant pressing force.
is pressed against the ribbon winding surface of the ribbon and rotated with a constant torque in the ribbon winding direction. As a result, the ink ribbon B is wound around the winding wheel 15 with a preset constant tension (tensile force) TI regardless of changes in the ribbon winding diameter.

On the other hand, as the ink ribbon B is wound up one after another, the first
As shown in the figure, the ribbon winding diameter of the take-up reel l5 becomes larger. Then, the tension spring 40 expands as the ribbon winding diameter changes through the rotation of the take-up roller 32 and the link plate 31 toward the outside of the reel.

The change in spring pressure caused by this stretching causes the take-up roller 32 to
is pressed against the ribbon winding surface of the winding roll 15 with a substantially constant pressing force. Therefore, as described above, a constant tensigon TI is given to the ink ribbon B regardless of the change in the ribbon winding diameter.

The tension spring 40 has a spring pressure of It is set so that a constant torque can be transmitted to the take-up roller 32.

As a result, regardless of changes in the ribbon winding diameter,
A constant tension TI in the winding direction is always applied to the ink ribbon B.

In the first embodiment shown in FIGS. 1 and 2, the winding roll 1
Reference numeral 5 is arranged at a position where a conventional ribbon winding pinch roller is arranged, or at a position near thereto. Accordingly, the winding motor l6, link plate 31, winding roller 32, spring 4
0. Each member such as the belt transmission mechanism is arranged closer to the platen 10 side.

FIG. 3 shows a second embodiment of the ink ribbon winding mechanism according to the present invention, and the same parts as in FIGS. 1 and 2 are given the same reference numerals, and the explanation thereof will be omitted.

Gears 41, 41 of the same diameter are attached to the drive shaft 161 of the winding motor 16.
' is installed.

An idler gear 42 attached to the link plate 31 is engaged with one gear 40. A gear 44 provided on the shaft of the take-up roller 32 is engaged with this idler gear 42. The take-up roller 32 is connected to a drive shaft 161 of the motor 16 via gear trains 4l to 44. Motor 1
The transmission torque applied to the take-up roller 32 from the winding roller 6 is kept constant by selecting and setting the gear ratios of the gear trains 4l to 44.

On the other hand, the intermediate gear 41 is connected to the other gear 41' of the drive shaft 161.
5 are engaged, and the gear 47 of the clutch 46 is engaged with the gear 45 in the middle. The gear 47 of the clutch 46 is
The coaxial shaft of the take-up roll 15 meshes with a gear 48 on the printer main body side. The bobbin 151 of the take-up liner 15 is coaxially connected to the gear 48 when the ink ribbon is loaded into the printer.

The torque transmitted from the motor 16 to the take-up reel 15 is kept constant through the intervention of the clutch 46.

As described above, the power transmission mechanism from the take-up motor 16 to the take-up roller 32 and from the take-up motor 16 to the take-up roll 15 is constituted by a gear mechanism consisting of a gear train. Even in this configuration, similarly to the first embodiment, the gear train 41 to
The take-up roller 32 rotates with a constant torque due to a constant transmission torque by the tension spring 44 and a substantially constant pressing force by the tension spring 40, and a constant tension TI is always applied to the ink ribbon B. Can be done.

Effects of the Invention As explained above, according to the present invention, the pinch roller for winding the ink ribbon, which was conventionally required, is no longer necessary, and the take-up reel is placed at or near that position, and the ink ribbon can be wound easily. The entire ribbon winding mechanism on the take-up side can be placed closer to the platen by the space that eliminates the need for the pinch roller. Therefore, the ink ribbon winding mechanism can be simplified and space saved, and the printer can be made smaller and more compact.

Further, regardless of the size of the ribbon winding diameter, it is possible to always apply a constant tension a to the ink ribbon only by the pressing action of one take-up roller.

As a result, uneven printing due to tension fluctuations is eliminated, and a structure suitable for high-quality printers can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the main parts of a printer according to the present invention;
2 is a partial side view of FIG. 1, FIG. 3 is a side view of a main part showing a second embodiment of the present invention, and FIG. 4 is a side view of a main part of a conventional presitter. 15. ．． ．． Take-up reel, 16●●●take-up motor, B●●●ink ribbon, 32●●●take-up roller, 31●●●link (plate), 33, 34●●●booley, 35●●●friction clutch , 351, 352●●●Pulley, 3E3, 37●●●Belt, 33', 221, 222, 38●●●Bouli, 22◆
●●Friction clutch, 23, 24 ●●● belt, 41 to 44 ●●● gear, 41', 45, 47 ●●● gear, 46 ●●● clasp.

Claims (5)

[Claims] (1) A pair of ink ribbon supply reel and take-up reel are provided via a platen, and a head is pressed into contact with the paper wound around the platen via the ink ribbon, and the ink ribbon is fed together with the paper while A printer that performs printing by heating a head includes: a take-up roller that is pressed against the outer peripheral surface of the take-up reel and rotated with a constant torque in the winding direction of the ink ribbon by the drive of a take-up motor; An ink ribbon winding device for a printer, comprising a biasing means for biasing and pressing a take-up roller against the outer peripheral surface of the take-up reel with a predetermined pressure contact force. (2) a take-up roller that is pressed against the outer peripheral surface of the take-up reel and rotated with a constant torque in the winding direction of the ink ribbon by the drive of the take-up motor; a link that supports the take-up motor so as to be rotatable around the ribbon; a power transmission means that transmits the driving force of the take-up motor to the take-up roller at a constant torque and rotates the take-up roller in the ribbon winding direction; An ink ribbon winding device for a printer, comprising urging means for urging and pressing a roller against the outer peripheral surface of the take-up reel at a predetermined pressure. (3) The ink of the printer according to claim (2), wherein the power transmission means is constituted by a winding transmission mechanism, and the winding transmission mechanism is provided with a friction clutch that makes the torque transmitted to the take-up roller constant. Ribbon winding device. (4) The ink ribbon winding device for a printer according to claim (2), wherein the power transmission means is constituted by a gear mechanism, and the gear mechanism is formed as a reduction gear train that keeps the torque transmitted to the winding roller constant. (5) The biasing means is constituted by a tension spring, and the spring pressure of the tension spring is set within the range of variation in the ribbon winding diameter of the take-up reel.
Claim (1), (2), (3) or (4), wherein the pressure contact force of the take-up roller is set within the predetermined pressure range.
) The ink ribbon winding device of the printer described in .