JPH0648004A - Ribbon cassette - Google Patents

Abstract

PURPOSE:To provide a ribbon cassette which does not allow a sheet to be contaminated by the contact with an ink ribbon during the printing and ensures the running stability of the ink ribbon. CONSTITUTION:The ribbon cassette 13 consists of an ink ribbon 18 wound around a pair of freely rotating reels 20a, 20b and a ribbon running path, the center of which leads to an area outside of the cassette and has a recessed part 26 where a printing head 25 is arranged. In addition, guide rollers 17b, 17c supported in such a manner that they rotate freely are provided at the upstream and the downstream side position of the recessed part in the ribbon running path, facing said path of both reels 20a, 20b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ribbon cassette for accommodating an ink ribbon therein, and more particularly to printing an image such as a predetermined character on a recording medium such as a sheet by selective heat generation of a heating element of a thermal head. The present invention relates to a ribbon cassette suitable for a thermal transfer printer.

[0002]

2. Description of the Related Art Generally, a recording medium such as paper and an ink ribbon coated with a desired ink are supported in front of a platen, and a thermal head having a plurality of heating elements arranged thereon is mounted on the platen together with a carriage. While reciprocating along the same, the ink ribbon is drawn out, and the heating elements arranged in alignment with the thermal head are selectively heated based on print information, so that desired characters or the like are printed on a recording medium such as paper. The thermal transfer printer that prints the image of
It is widely used as an output device for computers, word processors, etc. for reasons such as high printing quality, low noise, low cost, and ease of maintenance.

A conventional ribbon cassette used in such a thermal transfer printer will be described below with reference to FIG. Figure 6
FIG. 8 is a plan view showing a main part of a conventional ribbon cassette in a head-up state.

As shown in FIG. 6, a conventional ribbon cassette 1 has a pair of reels 3a and 3b rotatably supported in a pair of plane main body 2 and a ribbon path. A plurality of guide rollers 4, 4, ...

The pair of reels 3a and 3b are formed in a substantially cylindrical shape, and desired ink ribbons 5 are wound from both ends on the outer peripheral surface of each reel 3a and 3b. When the carriage (not shown) of the thermal transfer printer is mounted on the pair of reels 3a and 3b, one of the reels 3a and 3b serves as a take-up reel 3a for winding up the ink ribbon 5 of the portion used for printing, and the other one. Is a delivery reel 3b for delivering the ink ribbon 5.

On the inner peripheral surface of each reel 3a, 3b, a plurality of key grooves 6, 6, ... Are formed in a spline shape at intervals in the circumferential direction, and inside the reel 3a on the left side in the figure. The peripheral surface has a winding hole 7a with which a winding bobbin (not shown) is engaged.
The inner peripheral surface of the other reel 3b on the right side of the drawing is a delivery hole 7b with which a delivery bobbin (not shown) is engaged. In the printing state, the take-up bobbin is driven and back tension is applied by the delivery bobbin while the ink ribbon 5 is running in synchronization with the movement of the carriage.

Further, the flat platen 8 shown by the chain double-dashed line in the figure and the case body 2 of the ribbon cassette 1 on the side facing the sheet 9 as an example of the recording medium are also printed by the chain double-dashed line in the figure. A concave portion 11 in which the thermal head 10 as a head is arranged is formed, and an intermediate portion of the ink ribbon 5 is led out in the concave portion 11. Fixed guides 12 each having a curved surface in a direction facing the platen 8 are formed at both corners of the recess 11.

The ink ribbon 5 accommodated in the ribbon cassette 1 is a one-time ink ribbon used only in one direction depending on the traveling direction of the ink ribbon 5,
There are multi-time ink ribbons that are used reciprocally, and there are various types such as black ribbons, single-color ink ribbons such as red ribbons, and full-color ink ribbons of multiple colors depending on the color of the ink.

[0009]

However, in the above-described conventional ribbon cassette 1, during the printing operation, as shown in FIG. 6, the paper 9 is placed between the platen 8 and the ink ribbon 5 which is led out. In the head-up state in which the thermal head 10 is not in contact with the platen 8 and the carriage 8 moves (moves along the platen 8 of the ribbon cassette 1), for example, a line feed operation or the like, the paper 8 is ejected. When it falls toward the ribbon 5, the fixed guide 12,
There is a problem in that the ink portion of the ink ribbon 1 in the portion supported by 12 and the paper 9 come into contact with each other as if they rub against each other, and the paper 9 is stained with the ink and adheres to the paper.

Further, as shown in FIG. 7, in a head-down state in which the thermal head 10 is in contact with the platen 8 via the drawn out ink ribbon 5 and paper 9,
The ink ribbon path of the ink ribbon 5 becomes longer in the thermal head 10 portion due to the contact operation of the thermal head 10 toward the platen 8, and the thermal head 10
There is a problem that the positional relationship between the fixed guides 12 and 12 becomes distant and the running of the ink ribbon 5 becomes unstable.

When the printed portion of the paper 9 falls to the ribbon cassette 1 side, the printing portion of the paper 9 is fixed to the fixed guide 1.
2 and 12, the non-printed portion of the paper 9 becomes dirty, and abnormal stress is applied to the paper 9
There was a problem that there was an adverse effect such as scratches on the.

The present invention has been made in view of these points, and overcomes the above-mentioned problems in the conventional ones.
An object of the present invention is to provide a ribbon cassette capable of preventing paper stains due to contact between a paper and an ink ribbon during a printing operation and improving running stability of the ink ribbon.

[0013]

In order to achieve the above-mentioned object, a ribbon cassette according to the present invention according to claim 1 has an ink ribbon wound between a pair of rotatable reels, and a ribbon path of the ink ribbon. In a ribbon cassette having a concave portion in which a middle portion of the reel is led out to the outside and a print head is arranged in the middle portion, a guide roller that is rotatably supported and faces the ribbon paths of the reels is provided with the ribbon of the concave portion. The feature is that they are provided at the upstream and downstream positions of the route.

A ribbon cassette according to a second aspect of the present invention is the ribbon cassette according to the first aspect, wherein the guide roller is arranged at a position most protruding in the platen direction.

[0015]

According to the ribbon cassette of the present invention having the above-mentioned structure, the rotatably supported guide roller is provided at the upstream and downstream positions of the ribbon path of the ink ribbon in the recess. In the printing state, a ribbon path regulated by the guide rollers on both sides of the printing head is formed in the vicinity of the printing head, and stable running of the ink ribbon in the printing state can be obtained.

Further, according to the ribbon cassette of the present invention as defined in claim 2, since the guide roller rotatably supported is arranged at the most projecting position in the platen direction of the ribbon cassette, During printing, even if the printed part of the paper falls to the ribbon cassette side, the paper contacts the guide roller and the guide roller rotates, rubbing the printed part of the paper, and the unprinted part of the paper remains. It is possible to reduce stains and the addition of abnormal stress to the paper.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a plan view of a main part showing an embodiment of the ribbon cassette of the present invention, FIG. 2 is an enlarged plan view showing the main part of the ribbon cassette, and FIG. 3 is a side view of FIG. is there.

As shown in FIG. 1, the ribbon cassette 13 of this embodiment has a pair of case main bodies 14 each having a substantially rectangular plane.
A pair of reels 15a, 15 rotatably supported therein
b, and a pair of rotatably supported ribbon feed rollers 1
6a, 16b, and a plurality of guide rollers 17 facing the rotatably supported ribbon path, four guide rollers 17 in this embodiment.
a, 17b, 17c and 17d are provided.

The pair of reels 15a and 15b are formed in a substantially cylindrical shape, and desired ink ribbons 18 are wound from both ends on the outer peripheral surface of each reel 15a and 15b. When the pair of reels 15a and 15b is mounted on a carriage (not shown), one of the pair of reels 15a and 15b winds the ink ribbon 18 of the portion used for printing.
5a, and the other is a delivery reel 15b for delivering the ink ribbon 18. In addition, each reel 15a, 15b
A plurality of key grooves 19, 19, ... Are formed in a spline shape at intervals in the circumferential direction on the inner peripheral surface of the reel. The inner peripheral surface of the reel 15a on the left side in the drawing projects to a carriage (not shown). A winding hole 20a with which the winding bobbin provided is engaged.
The inner peripheral surface of the reel 15b on the right side of the drawing is a delivery hole 20b with which a delivery bobbin protruding from a carriage (not shown) is engaged.

The pair of ribbon feed rollers 16a, 16
b is formed in a substantially cylindrical shape, and when the pair of ribbon feeding rollers 16a and 16b is mounted on a carriage (not shown), one of them winds up a portion of the ink ribbon 18 used for printing. The ribbon feeding roller 16a for taking out the ink ribbon 18 and the ribbon feeding roller 16b for feeding the ink ribbon 18 are provided on the other side. Further, a plurality of key grooves 21, a plurality of key grooves 21, are formed on the inner peripheral surface of each ribbon feed roller 16a, 16b.
21 are formed in a spline shape at intervals in the circumferential direction, and the inner peripheral surface of the ribbon feed roller 16a on the left side in the drawing has a winding roller drive shaft projectingly provided on a carriage (not shown). Is an engaging hole 22a for engaging with, and the inner peripheral surface of the ribbon feeding roller 16b on the right side in the drawing is an engaging hole for engaging with a roller driving shaft for feeding, which is projectingly provided on a carriage (not shown). 22b. A covering sleeve 23 formed of a material having a relatively high friction coefficient such as a rubber-like elastic body is fixed to the outer circumference of each of the ribbon feeding rollers 16a and 16b by integral molding or fitting.

Further, the case body 14 of the ribbon cassette 13 on the side opposite to the platen 24 shown by the chain double-dashed line in the drawing is formed with a recess 26 in which a thermal head 25 as a print head is arranged. An intermediate portion of the ink ribbon 18 is led out inside.

The ribbon path of the ink ribbon 18 is covered with the covering sleeve 2 of the ribbon feeding roller 16b for feeding from the feeding reel 15b through the guide roller 17a.
It is arranged along the outer periphery of the case 3 at the position most protruding from the case body 14 in the platen 24 direction, and is guided to the thermal head 25 portion via the guide roller 17b arranged on the right side of the recess 26 in the drawing. Further, like the guide roller 17b, it is arranged at the most projecting position in the platen 24 direction, and the ribbon feed roller 16a for winding is covered via the guide roller 17c arranged on the left side of the recess 26 in the drawing. Along the outer circumference of the sleeve 23, the take-up reel 15 via the guide roller 17d.
It is designed to be wound around a.

The guide rollers 17b and 17c arranged on both sides of the recess 26 are rotatably supported near the tips of the arms 27, 27 extending on both sides of the recess 26 of the case body 14. ing. Further, guide ribs 28, 28 are provided at desired positions of the arm portions 27, 27.
Are provided, and the guide ribs 28, 28 form an ink ribbon path when the thermal head 25 heads up.

The ribbon feed rollers 16a and 16b are also provided.
The wrapping angle of the ink ribbon 18 with respect to the guide roller 17a, 17b, 17
The winding angles of c and 17d do not change between the winding start and the winding end of the ink ribbon 18, and are always the same. Further, each of the ribbon feed rollers 16a, 1
The coating sleeve 23 of 6b and the ink ribbon 18 are in contact with each other on the back surface side of the ink ribbon 18 on which the ink is not coated.

Further, the ribbon feeding roller 16 for feeding
b and the guide roller 1 arranged on the right side of the recess 26 in the drawing.
7b, a guide roller 17c arranged on the left side of the recess 26 in the drawing, and a ribbon path of a winding ribbon feed roller 16a are substantially linear, and the guide roller 17b, Platen 2 of 17c
4, the ink ribbon 18 passes through the portion on the far side with respect to 4.

Further, as shown in FIG. 2, the tip position of the guide roller 17b arranged on the right side of the recess 26 in the figure facing the platen 24 is a predetermined dimension A from the tip position facing the platen 24 of the case body 14. Only the platen 24 is projected. The same applies to the guide roller 17b arranged on the left side of the recess 26 in the drawing. In other words, both guide rollers 17b and 17c are arranged at the frontmost position with respect to the platen 24. The predetermined dimension A projected from the ribbon cassette 13 is preferably 1/2 or more of the outer diameter dimension of the guide rollers 17b and 17c.

Further, as shown in FIG. 3, the guide roller 1
Flanges 29, 29 are formed at the upper and lower ends of 7b, 17c, the diameter of which is increased outward in the axial direction. And
The flanges 29, 29 constrain the position of the ink ribbon 18 in the vertical direction in the figure.

Further, the guide rollers 17b and 17c are replaceable, and it is possible to arrange the guide rollers 17b and 17c having different outer diameters depending on the type of the ink ribbon 18.

Next, the operation of this embodiment having the above-mentioned structure will be described.

First, when the ribbon cassette 13 is mounted on the carriage of a thermal transfer printer (not shown), as shown in FIG. 1, the ink ribbon 18 led out to the recess 26 of the ribbon cassette 13 of the thermal head 25 shown by the broken line in the figure. A pair of roller drive shafts (both not shown), which are positioned in front of the carriage and project from the carriage, are engaged with the respective ribbon feed rollers 16a, 16b through engagement holes 22a, 22b formed in the ribbon cassette 13. The roller drive shaft and the ribbon feed rollers 16a and 16b are engaged with each other. The take-up bobbin and the delivery bobbin (both not shown) provided on the carriage project from the ribbon cassette 13.
The reels 15a and 15b are inserted into the reels 15a and 15b through the take-up hole 20a and the delivery hole 20b formed in the above, and the bobbins and the reels 15a and 15b are engaged with each other.

In such a state, when print information is input by an input device such as a keyboard (not shown), the thermal head 25 (head-up state) shown by a broken line in the figure causes the ink ribbon 18 and the sheet 30 to be printed based on the print information. And moves to the position (head-down state) indicated by the solid line in the figure and contacts the platen 24. Then, the thermal head 25 causes the ink ribbon 18 and the paper 30.
In the head-down state in which the thermal head 2 is in contact with the platen 24 via the thermal head 2 based on the input print information.
The heating elements of No. 5 selectively generate heat to melt the ink in the portions of the ink ribbon 18 that are in contact with the heated heating elements and transfer the ink to the sheet 30. After that, when the winding ribbon feed roller 16a and the winding reel 15a are rotationally driven in a predetermined direction, the winding ribbon feed roller 1
Due to the frictional force (tension) of the covering sleeve 23 of 6a, the portion of the ink ribbon 18 used for printing is separated from the paper 30. The ink ribbon 18 separated from the paper 30 is taken up by the take-up reel 15a via the outer circumference of the take-up ribbon feed roller 16a.

Further, both the ribbon feed rollers 16a, 1
The ink ribbon 18 contacting the 6b is the ink ribbon 18
The back surface of the ribbon feeding rollers 16a and 16b, which is not coated with the ink, comes into contact with the coating sleeve 23 formed of a material having a relatively high friction coefficient such as a rubber-like elastic body of the ribbon feeding rollers 16a and 16b. It is possible to reliably prevent the problem that the ink ribbon 18 adheres and the ink ribbon 18 sticks. The winding angle of the ink ribbon 18 with respect to both the ribbon feed rollers 16a and 16b is always a constant angle regardless of the use state of the ink ribbon 18 by the freely rotatable guide rollers 17a, 17b, 17c and 17d. Therefore, it does not change between the winding start state of the ink ribbon 18 and the winding end state of the ink ribbon 18. As a result, both ribbon feed rollers 16a, 16b
The frictional force between the coating sleeve 23 and the ink ribbon 18 does not change. For example, the frictional force decreases due to a decrease in the winding angle that occurs as the winding end of the ink ribbon 18 approaches, and the ink ribbon 18 caused by this reduction in frictional force. It is possible to surely prevent the slip of the ink ribbon 18 and a decrease in the peeling force of the ink ribbon 18 from the paper sheet 30 (in an extreme case, the ink ribbon 18 remains attached to the paper sheet 30) due to the slip.

Further, the ribbon feeding roller 16b for feeding
And the guide roller 17 arranged on the right side of the recess 26 in the drawing.
b and the guide roller 1 arranged on the left side of the recess 26 in the drawing.
7c and the ribbon feed roller 16a for winding up, the ribbon path of the portion is substantially straight in the head-up state, and the guide roller 17
Since the ink ribbon 18 is made to pass through the far side portion with respect to the platens b and 17c, the running stability of the ink ribbon 18 during printing can be improved. Then, the flange 2 of the guide rollers 17b and 17c
By 9, 29, the positional fluctuation of the ink ribbon 18 in the vertical direction can be suppressed within a predetermined range, so that the running stability of the ink ribbon 18 during printing can be further improved. Further, since a ribbon path that is substantially linear is formed in the vicinity of the recess 26, the ink ribbon 18
Can be easily attached to the ribbon cassette 13. Further, in the head-up state, as shown in FIG. 3, since the ink ribbon 18 is positioned with the guide rollers 17b and 17c separated from the paper 30, the paper 30 is caught by the ink ribbon 18 when the paper 30 is fed, The ink ribbon 18 may be pulled out from the ribbon cassette 13 and wasted, or the paper 30
It is possible to surely prevent problems such as dirt on the surface.

Further, even when the paper 30 falls down to the ribbon cassette 14 side during the print operation in the head-up state, for example, the line feed operation, the rotatable guide rollers 17b and 17c located at the frontmost position with respect to the platen 24. Since the sheet 30 and the sheet 30 come into contact with each other, unlike the conventional case, the sheet 30 is not stained with ink and adheres to the sheet 30.

Further, the thermal head 25 causes the platen 24 to pass through the drawn out ink ribbon 18 and paper 30.
Even if the printed sheet 30 falls down toward the ribbon cassette 14 in the head-down state where it abuts with the head-up state, similarly to the head-up state, the rotatable guide rollers 17b and 17c located at the frontmost position with respect to the platen 24. And paper 3
0 is in contact with the guide roller 17 when the printing portion of the sheet 30 contacts the guide rollers 17b and 17c.
It is possible to reliably prevent adverse effects such as the rotation of the b and 17c, the unprinted portion of the paper 30 becoming dirty, and abnormal stress applied to the paper 30 to damage the paper 30.

Further, the guide rollers 17b and 17c are replaceable, and those having different outer diameters can be arranged depending on the type of the ink ribbon 18, so that the composition and ink of the ink used depending on the type of the ink ribbon 18 can be arranged. Unlike the conventional ribbon cassette 1, the dedicated ribbon cassette 1 for each type of the ink ribbon 18 is not used for the optimum peeling angle α at which the ink ribbon 18 is peeled off from the paper 30 after printing due to the difference in the viscosity and the like. In addition, as shown in FIG. 4, this can be dealt with only by changing the guide rollers 17b and 17c, so that various parts of the ribbon cassette 18 can be shared and the economic burden can be reduced.

The distance between the guide roller 17b and the guide roller 17c, the platen 24 and the guide roller 17
The distance between b and 17c can be reduced.

If the center of the guide roller 17c and the center of the guide rib 28 are offset as shown in FIG. 5, the distance y between the tip of the guide roller 17c and the tip of the guide rib 28 can be reduced.

The present invention is not limited to the above embodiment, but can be modified as necessary.

[0041]

As described above, according to the ribbon cassette of the present invention, guide rollers rotatably supported are respectively provided at positions on the upstream and downstream sides of the ribbon path of the ink ribbon in the recess where the print head is arranged. Since it is provided, it is possible to reliably improve the running stability of the ink ribbon during printing. Further, since the guide roller is arranged at the forefront part with respect to the platen, even if the printed portion of the paper falls on the ink ribbon side, if the printed portion of the paper comes into contact with the guide roller, the guide roller Is rotated, and it is possible to remarkably reduce the stain on the unprinted portion of the paper.

[Brief description of drawings]

FIG. 1 is a plan view showing a main part of a ribbon cassette according to the present invention.

FIG. 2 is an enlarged plan view showing a main part of the ribbon cassette shown in FIG.

FIG. 3 is a side view of FIG.

FIG. 4 is an explanatory diagram illustrating a peeling angle of an ink ribbon.

FIG. 5 is an explanatory diagram illustrating a positional relationship between guide rollers and guide ribs.

FIG. 6 is a plan view showing a main part of a conventional ribbon cassette in a head-up state.

FIG. 7 is a plan view showing a main part of a conventional ribbon cassette in a head-down state.

[Explanation of symbols]

 13 ribbon cassette 14 case body 15a take-up reel 15b delivery reel 16a take-up ribbon feed roller 16b delivery ribbon feed roller 17a, 17b, 17c, 17d guide roller 18 ink ribbon 24 platen 25 thermal head 26 recess 28 guide rib

Claims (2)

[Claims] 1. A ribbon cassette having an ink ribbon wound between a pair of rotatable reels, an intermediate portion of a ribbon path of the ink ribbon being led out to the outside, and a concave portion in which a print head is arranged. 2. A ribbon cassette, wherein guide rollers rotatably supported facing the ribbon paths of both reels are provided at upstream and downstream positions of the ribbon path in the recess. 2. The ribbon cassette according to claim 1, wherein the guide roller is arranged at a position most protruding in the platen direction.