JPS59156786A - Back tension generator for ink ribbon - Google Patents

Abstract

PURPOSE:To reduce the overall size of a printer, by a method wherein a means for providing friction for rotation of a supplying spool and a member for exerting a back tension on an ink ribbon are provided between the supplyng spool and a base supporting the supplying spool. CONSTITUTION:An upper shaft of a rotary shaft 11 for a spool is disengageably engaged into a quadrilateral hole 6a provided in the supplying spool 6, and a lower shaft rotatably supports the spool 6 on an upper plate 12. An end of a spiral spring 14 for exerting a back tension on the ink ribbon 5 is engaged into a small hole 13a of a rotation-transmitting plate 13 rotated together with the supplying spool 6 by being engaged with the lower shaft of the shaft 11 and being rotatably slidden on the lower surface of the upper plate 12. A press plate 17 is slidably engaged with a lower plate 16, and a friction disk 19 placed on the press plate 17 is pressed against a slipping plate 15 by a coil spring 18. Accordingly, since each component part is provided in a space beneath the supplying spool 6 which space is not effectively utilized in a conventional system, the overall size of the printer can be reduced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to an impact printer that mechanically transfers ink from an ink ribbon to recording paper, or a thermal transfer printer that melts ink with heat and transfers it to recording paper. This invention relates to a pack tension generating device for an ink ribbon wound around a supply spool and a take-up spool.

(Structure of conventional example and its problems) A conventional impact type printer has a fourteenth structure as shown in FIG. In FIG. 1, a print head 1 is placed on a carriage 2 and moves parallel to a platen 4 holding a recording paper 3. An ink ribbon 5 is wound around both ends of the platen 4 by a supply spool 6 and a take-up spool 7, and is brought into contact with the print head via a ribbon roller 8 provided on the carriage 2. While the print head 1 moves from the take-up spool 7 to the supply spool 6, ink in the ink cartridge 5 is transferred onto the recording paper 3 to perform printing. 1, the ink ribbon 5u is wound around the preliminary supply spool 6 and is pulled out from the supply spool 6v as necessary by rotating the take-up spool 7 driven by a motor etc. in the direction of the arrow in the figure. and is wound onto the take-up spool 7. At this time, if the ink ribbon 5 is simply wound up, the ink ribbon 5 between the print head 1 and the supply spool 6 will bend when the print head 1 moves, causing problems in the position of the ink ribbon 5 and resulting in poor print quality. decreases. Therefore, the supply spool 611
A tension generator is attached to the ink ribbon 11, in which a swingable tension lever 9 is brought into pressure contact with a coil spring 1o, and a constant tension is applied to the ink ribbon 5. However, such conventional bank tension generators and tension levers
Since the coil springs 9 and 10 are located on the same plane as the supply spool 6, a relatively large space is required, which is one of the problems in miniaturizing printing devices.

(Objective of the Invention) The present invention is an improvement made in view of the drawbacks of the above-mentioned conventional example, and provides an ink ribbon pack tension generating device that enables downsizing of a printing device.

(Structure of the Invention) In order to achieve the above object, the present invention provides a means for applying friction to the rotation of the supply spool and a spring member that applies hack tension to the ink ribbon between the supply spool and a base that supports the supply spool. It is arranged with.

(Explanation of Examples) Hereinafter, two embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows the structure of the first embodiment of the present invention, and FIG. 3 shows an exploded perspective view thereof. In FIGS. 2 and 3, a supply spool 6 has an ink ribbon 5 wound thereon and has a square hole 6a in its center. Reference numeral 11 denotes a spool rotation shaft with a shaft passing through the center of a disc-shaped member.The disc-shaped member divides the shaft into two shafts and a lower shaft, and the upper shaft can be freely attached to and removed from the square hole 6a of the supply spool 6. and the lower shaft passes through the soil plate 12, and the supply spool 6 is connected to the upper plate 1.
It is rotatably held on 2. 13 is a rotation transmission plate that fits into the lower shaft of the spool rotating shaft 11 and rotatably slides on the lower surface of the upper plate 12 to rotate together with the supply spool 6;
A part thereof has a small hole 13a, and one end of a spiral spring 14, which serves as a spring member that applies a tension force to the ink ribbon 5, is locked in this small hole 13a. Reference numeral 15 denotes a clip plate which rotatably slides on the rotation transmission plate 13 and has the other end 1 of the spiral spring 14 locked in a small hole +5a provided in a part of the clip plate, and is a lower plate which is the base of this embodiment. The spool rotating shaft 110 is rotatably held at the tips of the upper shaft protruding from the earth surface of the presser plate 17 which is fitted in a non-rotatable manner to the spool rotating shaft 116 so as not to rotate. The presser plate 17 is slidably fitted to the lower plate 16, and a friction disk 19 made of felt or the like placed on the presser plate 17 is pressed against the slip plate 15 by a coil spring 18. There is.

” = In the configuration, printing is in progress or printing has finished,
When the take-up spool 7 rotates and the ink ribbon 5 is pulled out from the supply spool 6, the supply spool 6 rotates together with the spool rotation shaft 11 to rotate the rotation transmission plate 13 fitted to the spool rotation shaft 11. At this time, the rotation transmitting plate 13 rotates in a direction to unwind the spiral spring 14 to which a part of the rotation transmission plate 13 is locked, but the slip plate 15 to which the other end of the spiral spring 14 is locked is connected to the holding plate 17 and the coil. Spring 8 is in pressure contact with the inner disc 19 of Jq, and the frictional force prevents it from rotating, so the spiral spring I4 winds up.
I get kicked. When the ink ribbon 5 is further pulled out, the spiral spring 14 is further wound, and when it is wrapped so that there is no gap, the repulsive force of the spiral spring 14 is greater than the frictional force between the slip plate 5 and the friction disk 19. When it becomes larger, a slip occurs between the slip plate 15 and the friction disk 19, and the slip plate 15 rotates together with the rotation transmission plate 13. When the ink ribbon 5 is pulled out in this state, the spiral spring 14 is wound around the slip plate 1 at the L position.
5 continues to slide on the friction disk 19''2.

Next, when the ink ribbon 5 is not pulled out by a predetermined amount, the rotation of the take-up spool 7 is stopped and the supply spool 6 is stopped.
rotation stops, and there is no slipping between the slip plate 15 and the friction disk '19. Normally, after this, the carriage 2 moves to the take-up spool 7 side and printing is performed, but at this time the print head 1 is connected to the platen 4 by the amplifier.
The ink ribbon 5 is bent due to the bending and the like. However, the spiral spring 14 that was wrapped around it unraveled,
At this time, since the slip plate 15 does not rotate due to the J1 friction with the friction disk 19, the repulsive force of the spiral spring 14 causes the rotation transmission plate 13 to rotate in the opposite direction to the direction when pulling out the ink ribbon 5. , dispose of the spool rotation shaft 11 and rotate the supply spool 6 in the direction in which the ink ribbon 5 is wound. Therefore, the deflection of the ink ribbon 5 is reduced by the supply spool 6.
By winding it up, the ink ribbon 5 can be kept stretched at all times.

FIG. 4 is a diagram showing the configuration of a second embodiment of the present invention. In this embodiment, a torsion coil spring 20, which is the spiral spring 14 in the first embodiment shown in FIG. 2 with the function of the coil spring 18, is used as a spring part. Moreover, the rotation transmission plate 22 and the slip plate 23 are connected at both ends between the rotation transmission plate 22 which rotatably slides on the lower surface of the upper plate 12 and the slip plate 23 which is rotatably held on the spool rotation shaft 21. The torsion coil springs 20 are arranged so as to be engaged with the lower plate 1, and the slip plate 23 is fixed to the lower plate 1.
It is brought into pressure contact with a 1q friction disk 24 placed on a 60-meter. By configuring as described above, the presser plate 17 and the coil spring 18 shown in FIG. 2 can be omitted, and the number of parts can be reduced.

FIG. 5 is a diagram showing the configuration of a third embodiment of the present invention. In this embodiment, a torsion coil spring 20 is disposed between a lower plate 16 and a holding plate 25, and the holding plate 25 is rotatably held on a spool rotation shaft 26, and is placed on the holding plate 25. This embodiment has a friction disc 27 pressed against a slip plate 28 which rotates together with the spool rotation shaft 26, and has a configuration that is almost vertically reversed from that of the second embodiment.

FIG. 6 is a diagram showing the configuration of a fourth embodiment of the present invention'.
In contrast to the first, second and third embodiments, in which each component is stacked in the longitudinal direction of the spool rotation shafts 11, 21 and 26, the components in this embodiment are stacked coaxially in the lateral direction. This is what was placed. In Figure 6, 29
is fitted with the supply spool 6 on which the ink ribbon 5 is wound to rotatably hold the supply spool 6 on the second plate 12, and a rotation transmission plate is provided between the soil plate 6 and the lower plate 16. 30
This is the spool rotation shaft that locks the spool. Reference numeral 31 denotes a spiral spring made of a leaf spring, which is fixed at both ends to the rotation transmission plate 30 and an annular slip plate 32 disposed coaxially on the outside of the rotation transmission plate 30. The reason why the leaf springs are used is to prevent the springs from shifting from each other when the ink is drawn out and the spiral springs 31 are turned. In addition, 33 is a friction/crad, which is installed at the other end of the friction pad presser arm 34 rotatably supported by the two plates 1 and 2. The slip plate 32 is pressed against the outer circumferential surface of the slip plate 32 by a coil spring 35 installed between the pad and the substantially center of the hold-down arm 34. The present embodiment configured in this manner can be made thinner than the first, second, and third embodiments, and the printing device can be further miniaturized.

In addition, in the first, second, and third embodiments, the second embodiment is similar to the first, second, and third embodiments.

- 1 tone each on the rotary shafts 11.21 and 26, respectively;
Although the parts were arranged coaxially and stacked, the IQI+ of each part
is divided and arranged on multiple shafts, and each gear is used to control the vehicle movement.
It can also be configured to
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(Effects of the Invention) As described above, the present invention provides a printing device in which a 4y ink ribbon is wound around a supply spool and a take-up spool, and the take-up spool is rotated to pull out the ink ribbon from the supply spool. Since each part is installed in the space under the supply spool that was not being used effectively, the entire printing device can be made smaller, and it is highly safe because no unnecessary force is applied from outside. Furthermore, since it does not have a structure that acts directly on the ink ribbon, it has the advantage that it is easy to remove the ink ribbon.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional printing device, FIG. 2 is a sectional view of a first embodiment of the present invention, and FIG. 3 is a perspective view of the first embodiment of the present invention. Figure 4 is a sectional view of the second embodiment of the present invention, Figure 5 is a sectional view of the third embodiment of the invention, and Figures 6(a) and (b) are the fourth embodiment of the invention. FIG. 2 is a front view and a plan view of an embodiment of the invention. 1 ・・・・・・・・・-1] head, 3 ・・・・・・
・Recording paper, 5... Ink ribbon, 6...
Supply spool, 7... Winding Lisbourg,
11,2]. 26, 29-...Spool rotation axis, 12...
... Upper plate, 14.3] ... Spiral spring, ]
5.23.28゜32... Slip plate, 16.
...Lower plate, 17°25... Holding plate, 19.
24.27 ・・・・・・1q rubbing disc, 20・・・・・・
Torsion coil spring, 33... Thick inner pad. Figure 1 Figure 2 Figure 3 G), +8 Figure 4 It) Figure 5 6 Figure 6 (0) (b)

Claims (3)

[Claims] (1) The ink ribbon wound around the supply spool is wound around a take-up spool and interposed between the print head and the recording paper, and the ink on the ink ribbon is mechanically or thermally injected. In a printing device that prints characters and other characters by transferring them onto the recording paper, drives the take-up spool to wind up the ink ribbon used for printing, and pulls out the ink ribbon wound around the supply spool, between the supply spool and the base supporting it;
A pack tension generating device for an ink printer characterized in that a means for applying friction to the supply spool that rotates when the ink ribbon is pulled out, and a spring system for applying back tension to the ink ribbon are interposed. . (2) The patent characterized in that the means for applying friction is such that the base body or a pressing member provided on the base body is in pressure contact with a slip plate that rotates in accordance with the rotation of the supply spool via a friction member. An ink ribbon pack tension generating device according to claim (1). (3) The spring member for applying the bar tension is disposed at a distance between the supply spool and the slip plate and between the presser member and the base body. The ink ribbon bank tension generator according to item (2).