JPH074932Y2 - Ribbon guide device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a ribbon guide device used in a printer.

2. Description of the Related Art Conventionally, as shown in FIG. 4, a rotary shaft 53, 54 is rotatably supported by a side plate 52 holding a platen 50 and a thermal head 51, and one end of a guide shaft 55 is fixed. A light emitting element 56 for detecting the end of the ribbon 58 and a light emitting element 57 are provided to face each other, and a ribbon cassette 61 having a pair of spools 59, 60 for holding the ribbon 58 in a wound state from both ends is provided. The ribbon cassette 61 is attached to the side plate 52 by fitting the light emitting element 56 and the light receiving element 57 to the ribbon cassette 61 by fitting the ribbon cassette 61 to the rotating shafts 53 and 54. There is a ribbon cassette 61 in which a plurality of guide rollers 62 and 63 are provided on the upstream side and the downstream side of the light receiving element 57 and 56 to maintain the path of the ribbon 58 in a straight line.

However, in such a device, a plurality of guide rollers 62 and 63 must be attached to the ribbon cassette 61 only to pass the ribbon 58 between the light emitting element 56 and the light receiving element 57. . Also, there is play in the mating portions of the rotary shafts 53, 54 and the spools 59, 60 so that the side plate 52 and the side surface of the ribbon cassette 61 are not necessarily parallel, but the platen 50 and the guide rollers 62, 63 should be parallel. Difficult to maintain. Therefore, it becomes difficult to uniformly contact the entire area of the ribbon 58 in the width direction with the platen 50, and there is a problem that print quality is affected.

Means for Solving the Problems A side plate rotatably supporting one end of two parallel rotating shafts, at least one of which is driven by a driving unit, is provided, and the ribbon is held in a wound state from both ends, and the rotation is performed respectively. A ribbon cassette having a pair of spools fitted to a shaft is provided, and one end is held by the side plate and a guide shaft for guiding the ribbon from the spool on the supply side to the printing unit is provided, and the ribbon is opposed to the guide shaft. A detector having a light emitting element and a light receiving element, one end of which is fixed to the side plate at a position on the upstream side of the guide shaft, is positioned near the upstream side of the detector and abuts on the ribbon. The ribbon is linearly formed between the light emitting element and the light receiving element and on the outer circumference of the guide shaft, and has a rotation fulcrum and an abutting portion located near the downstream side of the guide shaft and abutting on the ribbon. Ribbon guide leading to The ribbon cassette is provided rotatably, one end of which is fixed to the side plate and which abuts against the ribbon guide when the rotary shaft and the spool are fitted to retract the ribbon guide from the ribbon.

Therefore, before attaching the ribbon cassette to the side plate,
Part of the path of the ribbon is supported by the rotation fulcrum of the ribbon guide and the abutting part, and is defined in a straight line. Therefore, when the spool and the rotating shaft are engaged, the ribbon manually corrects the path. Without being guided, it is guided between the light emitting element and the light receiving element and to the outer circumference of the guide shaft. This facilitates mounting of the ribbon cassette on the side plate. Further, since the ribbon can be positioned with respect to the detector and the guide shaft by one ribbon guide having the rotation fulcrum and the contact portion, the number of parts of the ribbon cassette can be reduced and the structure can be simplified. . Further, during the fitting operation of the spool and the rotation shaft, the ribbon guide is retracted from the ribbon by the pressing body, so that the ribbon is guided to the platen by the guide shaft which is supported by the side plate and has an accurate parallelism to the platen. It is possible to bring the entire area of the ribbon in the width direction into uniform contact with the platen.

Embodiment An embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 denotes a side plate, and on the side plate 1, two rotary shafts 3 and 4 having a plurality of protrusions 2 on the outer periphery are rotatably supported. One of the rotary shafts 3 is connected to the drive unit. Reference numeral 5 denotes a ribbon cassette. The ribbon cassette 5 has two supporting plates 7 having a plurality of cylinder shafts 6 opposed to each other, and
Of the spools 8 and 9 are rotatably mounted on these support plates 7, and the tips of the ribbons 13 wound on one spool 9 are attached to the other spool 8. It was fixed on. Further, the cylindrical shaft 6 is tapered so as to become gradually thinner toward the tip. Further, these spools 8 and 9 are fitted to the rotary shafts 3 and 4, and a plurality of ridges 10 that mesh with the ridges 2 of the rotary shafts 3 and 4 are formed on the inner peripheral surface. .

Next, one end of the two guide shafts 11 and 12 is supported by the side plate 1 in a cantilevered state, and one end of a detector 16 having a light emitting element 14 and a light receiving element 15 facing each other with the ribbon 13 in between is attached. It is fixed. A spherical expanding portion 17 is integrally formed at the end portions of the guide shafts 11 and 12 on the free end side. Further, a notch 18 for letting the guide shaft 12 and the detector 16 escape is formed in the lower portion of the support plate 7. Further, a ribbon guide 21 having a rotation fulcrum 19 rotatably fitted to the shaft 6a positioned near the notch 18 of the plurality of shafts 6 and a contact portion 20 for contacting the ribbon 13 is provided. 5 is provided. The ribbon guide 21 is biased counterclockwise (downward) by a torsion spring (not shown) wound around the shaft 6a, but is fixed by a stopper (not shown) formed on the support plate 7. It is located in position. Further, a platen 22 and a thermal head 23 elastically contacting the platen 22 are mounted on the side plate 1, and one end of a pressing body 24 for pressing one side of the lower surface of the ribbon guide 21 is fixed. There is. The pressing body 24 has a shaft shape, and a taper 25 is formed on the free end side thereof.

In such a configuration, before the ribbon cassette 5 is mounted on the side plate 1, the spool 13 on the take-up side is manually rotated to the take-up side, so that the ribbon 13 pulled out from the spool 9 is pulled out.
Is given a tension as shown in FIG. Therefore, when the spools 8 and 9 are fitted to the rotating shafts 3 and 4 in this state, a part of the ribbon 13 is located on the rotation fulcrum 19 located on the upstream side of the detector 16 and on the downstream side of the guide shaft 12. Since it is maintained in a straight line with the abutting portion 20 located, the ribbon 13 is moved to the detector 16 and the guide shaft 12.
It is possible to mount the Boncassette 5 on the side plate 1 without interfering with, that is, to insert the ribbon 13 between the light emitting element 14 and the light receiving element 15 without modifying the path of the ribbon 13 by hand and to guide the guide shaft 12. Can lead to the lower side. Also,
In the latter half of the process of fitting the spools 8 and 9 to the roots of the rotating shafts 3 and 4, as shown in FIG.
It is pushed up little by little by the taper 25 of 24 and rotates clockwise, so that it is separated from the ribbon 13. Then, the ribbon 13 is slightly pulled out from the spool 9, passed between the platen 22 and the thermal head 23, and wound around the upper guide shaft 11. Then, print on the paper 26 with the thermal head 23,
The sheet 26 and the ribbon 13 are fed in a superposed state by the rotation of the platen 22, and the ribbon 13 is wound around the spool 8 by the fed amount by rotating the rotary shaft 3 in the clockwise direction.

As described above, since the ribbon can be positioned with respect to the detector 16 and the guide shaft 12 by the single ribbon guide 21 having the rotation fulcrum 19 and the contact portion 20, the number of parts of the ribbon cassette 5 is reduced and the structure is simplified. Can be converted. Also,
With the ribbon cassette 5 attached to the side plate 1, the pressing body is
In order to retract the ribbon guide 21 from the ribbon 13 by 24, the ribbon 13 is guided to the platen 22 by the guide shaft 12 which is supported by the side plate 1 and has the parallelism with respect to the platen 22. The print quality can be improved by uniformly contacting the platen 22.

Effect of the Invention Since the present invention is configured as described above, before the ribbon cassette is attached to the side plate, a part of the ribbon path can be linearly defined by the rotation fulcrum of the ribbon guide and the contact portion. Therefore, during the fitting operation of the spool and the rotary shaft, the ribbon can be guided between the light emitting element and the light receiving element and to the outer circumference of the guide shaft without manually correcting the path, and thus the ribbon can be guided to the side plate. The ribbon cassette can be easily attached, and the ribbon can be positioned with respect to the detector and the guide shaft by one ribbon guide having a rotation fulcrum and an abutting portion, so that the number of parts of the ribbon cassette can be reduced. The structure can be reduced, and the structure can be simplified. Further, since the ribbon guide is retracted from the ribbon by the pressing body during the fitting operation of the spool and the rotary shaft, the ribbon guide is supported by the side plate and faces the platen. The ribbon is guided to the platen by an accurate guide shaft with parallelism, and thus, the entire area in the width direction of the ribbon is brought into uniform contact with the platen to improve the printing quality.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is an exploded perspective view, FIG. 2 is a vertical sectional side view showing a process of mounting a ribbon cassette on a side plate, and FIG. 3 is a ribbon. FIG. 4 is a vertical sectional side view showing a state in which the cassette is attached to the side plate, and FIG. 4 is a side view showing a conventional example. 1 ... Side plate, 3, 4 ... Rotating shaft, 5 ... Ribbon cassette, 8, 9 ... Spool, 12 ... Guide shaft, 13 ... Ribbon, 14 ... Light emitting element, 15 ...
Light receiving element, 16 ... Detector, 19 ... Rotation fulcrum, 20 ... Abutment part, 21
… Ribbon guide, 23… Thermal head (printing part), 24…
Pressing body

Claims (1)

[Scope of utility model registration request] 1. A side plate for rotatably supporting one ends of two parallel rotary shafts, at least one of which is driven by a drive unit, is provided, and the ribbon is held in a wound state from both ends and fitted to the rotary shafts. Provided is a ribbon cassette having a pair of spools to be fitted together, one end of which is held by the side plate and which is provided with a guide shaft for guiding the ribbon from the spool on the supply side to the printing unit, and the light emitting element facing each other with the ribbon in between A rotation fulcrum having a light receiving element and one end fixed to the side plate at a position on the upstream side of the guide shaft and located near the upstream side of the detector and contacting the ribbon. A ribbon that linearly guides the ribbon between the light emitting element and the light receiving element and on the outer periphery of the guide shaft, the ribbon having an abutting portion located near the downstream side of the guide shaft and abutting on the ribbon. Guide the ribbon cassette And a pressing member that is fixed to the side plate and has one end abutted against the ribbon guide when the rotary shaft and the spool are fitted to retract the ribbon guide from the ribbon. Ribbon guide device.