JPH0655819A - Ribbon cassette - Google Patents

Abstract

PURPOSE:To provide a ribbon cassette which can contrive miniaturization and an improvement in printing life by simple structure. CONSTITUTION:In a ribbon cassette wherein an ink ribbon 6 is passed round a pair of freely turnable reels 3, an intermediate part of a ribbon route of the ink ribbon 6 is led outside and the intermediate part possesses a recessed part 20 into which a printing head 12 is arranged, it is constituted by allowing a form of the bottom part 21 of the recessed part 20 approximate to a form of the maximum wound up diameter R1 of the ink ribbon 6 wound round the reel 3 so as to run along the same.

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.

Two types of conventional ribbon cassettes used in such a thermal transfer printer, which will be described below, are used corresponding to the positional relationship of the print head with respect to the carriage.

First, the first conventional ribbon cassette is shown in FIG.
Will be described.

FIG. 4 is a plan view showing the structure of a main part of a first conventional ribbon cassette.

As shown in FIG. 4, the first conventional ribbon cassette 1 has a pair of rotatably supported reels 3 and a pair of rotatably supported reels 3 in a case body 2 having a substantially rectangular plane. A pair of ribbon feed rollers 4 and four guide rollers 5 facing the rotatably supported ribbon path are arranged.

The pair of reels 3 are formed in a substantially cylindrical shape, and desired ink ribbons 6 are wound from both ends on the outer peripheral surface of each reel 3. When the pair of reels 3 is mounted on a carriage (not shown), one of them, for example, the left side in the drawing is a take-up reel 3a for winding the ink ribbon 6 of the portion used for printing, and the other is the ink. The reel 6 serves as a delivery reel 3b for delivering the ribbon 6. Further, on the inner peripheral surface of each reel 3a, 3b, a plurality of key grooves 7, 7,
Are formed in a spline shape at intervals in the circumferential direction, and the inner peripheral surface of the take-up reel 3a on the left side of the drawing is wound with a take-up bobbin protruding from a carriage (not shown). A delivery hole 8a is formed, and an inner peripheral surface of the delivery reel 3b on the right side in the drawing is formed as a delivery hole 8b with which a delivery bobbin protruding from a carriage (not shown) is engaged.

The pair of ribbon feed rollers 4 are formed in a substantially cylindrical shape.
When mounted on a carriage (not shown),
For example, the left side of the figure shows the ink ribbon 6 of the portion used for printing.
Is a ribbon feeding roller 4a for winding up the ink, and the other is a ribbon feeding roller 4b for sending out the ink ribbon 6. In addition, each ribbon feed roller 4a, 4b
A plurality of key grooves 9, 9, ... Are formed in a spline shape at intervals in the circumferential direction on the inner peripheral surface of, and the inner peripheral surface of the ribbon feeding roller 4a for winding on the left side in the drawing is An engaging hole 10a into which a winding roller drive shaft projecting from a carriage (not shown) is engaged, and an inner peripheral surface of a ribbon feeding roller 4b for feeding on the right side in the drawing has a carriage (not shown). It is an engaging hole 10b with which the roller drive shaft for delivery, which is provided in a protruding manner, is engaged. A covering sleeve 11 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 ribbon feed roller 4a, 4b by integral molding or fitting.

Further, a substantially rectangular plane-shaped concave portion 13 in which a thermal head 12 as a print head is arranged is formed at a substantially central portion in a longitudinal direction of a case body 2 of a ribbon cassette 1 on a side facing a platen (not shown). The ribbon cassette 1 has a linear bottom portion 14 on the central portion side. The intermediate portion of the ink ribbon 6 is led out in the recess 13.

The ink ribbon 6 accommodated in the ribbon cassette 1 is a one-time ink ribbon used only in one direction depending on the running direction of the ink ribbon 6.
There are multi-time ink ribbons and the like that are used in the reciprocating direction by reversing the front and back, and there are various types such as single color ink ribbons such as black ribbons and red ribbons and full color ink ribbons having a plurality of colors depending on the ink color.

Next, the second conventional ribbon cassette will be described with reference to FIG.

FIG. 5 is a plan view showing the structure of the main part of a second conventional ribbon cassette. The same or corresponding components as those of the first conventional ribbon cassette described above are designated by the same reference numerals in the drawings, and detailed description thereof will be omitted.

The second conventional ribbon cassette 1a is shown in FIG.
As shown in FIG. 1, a pair of rotatably supported reels 3 and five guide rollers 5 rotatably supported facing the ribbon path are provided in a case body 2a having a substantially rectangular plane. Has been done.

Further, the case main body 2a of the ribbon cassette 1a on the side facing the platen (not shown) is provided with two recessed portions 13a, 13a having a substantially rectangular plane in which the thermal head 12 as a print head is arranged. The thermal head 12 is arranged in the recess 13a on the left side of the drawing. Each of the recesses 13a, 13a has a linear bottom portion 14a on the center side of the ribbon cassette 1a. Further, the intermediate portion of the ink ribbon 6 is led out in the recess 13a. Other configurations are the same as those of the first conventional ribbon cassette 1 described above.

[0015]

By the way, at present,
The thermal transfer printer using such a ribbon cassette has been constantly improved in performance and size, and it is desired to reduce the size and performance of the ribbon cassette, and particularly to improve the printing life.

However, as shown in FIG. 4, in the above-mentioned first conventional ribbon cassette 1, the concave portion 13 in which the thermal head 12 is arranged has a linear bottom portion 1.
Since it is a substantially rectangular plane having four, the reel diameter r
And the distance B between the center of the reel and the print position and the thickness t of the ink ribbon are the same, the bottom portion 14 of the recess 13 is
Ink ribbons that can be stored in the ribbon cassette 1 depending on the positions of the end portions 15, 15 of the recesses 15, that is, the widthwise size of the recess 13 shown by H in the figure and the size of the recess 13 by the depthwise direction shown in FIG. The maximum winding diameter R of 6 and the distance A between reels are constrained, and an extra space 17 shown by a shaded portion in FIG. 4 is generated, so that it is impossible to improve the printing life (total length of the ink ribbon). there were.

As shown in FIG. 4, when the position of the thermal head 12 at the time of printing is set to the position shown by the broken line in the figure, the thermal head 12 at the initial position shown by the one-dot chain line in the figure shows the arrow in the figure. The thermal head 12 at the initial position shown by the solid line in the figure with respect to the position of the bottom portion 14 shown by the dashed line in the figure when the slide system that operates as indicated by L is used.
However, the position of the bottom portion 14 shown by the solid line in the case of the rotation system that operates as indicated by the arrow K in the figure is closer to the reel 3 side. That is, when the thermal head 12 of the rotating type is used, the length D in the depth direction of the recess 13 becomes large, and the maximum winding diameter of the ink ribbon 6 must be made small. Ribbon chief)
However, there was a problem that it became shorter.

Further, as shown in FIG. 6, the pressure contact angle α between the platen 16 and the thermal head 12 shown by the broken line in the figure at the printing position of the above-mentioned slide system is generally 1
However, in order to correspond to a paper called rough paper such as straw paper, which has a lot of irregularities on the surface and has poor paper quality, like the thermal head 12 shown by the solid line in the figure, for example, 3 to 5 is used.
It may be set every time. When the press contact angle α is increased in this way, the depth direction D of the concave portion 13 is also increased as shown by the one-dot chain line in the figure, and the maximum winding diameter R of the ink ribbon 6 must be reduced, and the printing life (ink There is a problem that the total length of the ribbon) becomes shorter.

The present invention has been made in view of these points, and overcomes the above-mentioned problems in the conventional ones.
It is an object of the present invention to provide a ribbon cassette which has a simple structure and can be downsized and the printing life can be improved.

[0020]

In order to achieve the above-mentioned object, the ribbon cassette of the present invention has an ink ribbon wound between a pair of rotatable reels, and an intermediate portion of the ribbon path of the ink ribbon is exposed to the outside. In the ribbon cassette that is drawn out and has a recess in which the print head is arranged in the middle part,
It is characterized in that the shape of the bottom of the recess is approximated so as to follow the shape of the maximum winding diameter of the ink ribbon wound around the reel.

[0021]

According to the ribbon cassette of the present invention having the above-described structure, the shape of the bottom of the recess in which the print head is disposed is set to the maximum winding diameter of the ink ribbon wound around the pair of rotatable reels. Since the shape is approximated so as to conform to the shape, the conventional useless space of the concave portion can be effectively used for expanding the winding diameter of the ink ribbon and / or reducing the size of the ribbon cassette.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. The same or corresponding structures as those of the conventional ribbon cassette described above are designated by the same reference numerals in the drawings, and detailed description thereof will be omitted.

FIG. 1 is a plan view for explaining the structure of the main part of the first embodiment of the ribbon cassette of the present invention.

As shown in FIG. 1, the ribbon cassette 18 of the present embodiment has a case body 1 which is substantially the same shape as the first ribbon cassette 1 described above and which is substantially rectangular in plane and has the same size.
A pair of rotatably supported reels 3, a pair of rotatably supported ribbon feed rollers 4, and four guide rollers 5 facing the rotatably supported ribbon path are provided inside And are provided. The pair of reels 3 are formed in a substantially cylindrical shape, and desired ink ribbons 6 are wound from both ends on the outer peripheral surface of each reel 3.

A recess 20 is formed in the case body 19 of the ribbon cassette 18 on the side opposite to a platen (not shown) at a substantially central portion in the longitudinal direction thereof. The ribbon cassette 18 has a bottom portion 21 on the center side thereof.
Then, the intermediate portion of the ink ribbon 6 is led out in the recess 20.

The recess 20 has a size D1 in the depth direction on both side surfaces thereof made shorter than the size D in the depth direction of the conventional recess shown by a broken line in the figure, and the ink wound around the reel 3 is made. The ribbon 6 has a substantially roof-like shape that projects toward the central portion between the reels 3a and 3b so as to follow the shape of the maximum winding diameter R1. The feature of the ribbon cassette 18 of this embodiment is that the shape of the bottom portion 21 differs from the shape of the conventional linear bottom portion 14 shown by the broken line in the figure.

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

As shown in FIG. 1, the depth 21 of the bottom portion 21 of the recess 20 of the ribbon cassette 18 in the depth direction of both side surfaces of the ribbon cassette 18 is determined from the size D of the conventional recess 14 in the depth direction shown by the broken line in the figure. By making the length shorter and following the shape of the maximum winding diameter R1 of the ink ribbon 6 wound around the reel 3, a substantially roof-like shape is projected toward the central portion between the reels 3a and 3b. The useless space 17 of the conventional ribbon cassette 1 can be removed, and the maximum winding diameter R1 of the ink ribbon 6 can be made larger than the maximum winding diameter R of the conventional ink ribbon 6.

More specifically, the maximum winding diameter R1 of the ink ribbon is restricted by the conventional linear bottom portion 14 shown by the broken line in the figure even if the case body 19 of the same size as the conventional one is used. It is possible to surely make the diameter larger than the maximum winding diameter R of 6, and it is possible to extend the total length of the ink ribbon 6 and improve the printing life. Similarly, the distance A1 between the reels can be shortened, and the longitudinal direction of the ribbon cassette 18 can be shortened.

Further, the ribbon cassette 18 of this embodiment is
Other than the length of the case main body 19 and the ink ribbon 6, the conventional one can be used in common, so that it is possible to reduce the economic burden and the development time involved in the development of the ribbon cassette 18, and moreover, to reduce the manufacturing cost. This has the effect of reducing the financial burden and the labor of parts management.

When the ink ribbon 6 having the same maximum winding diameter R as the conventional one is used, the distance A1 between the reels and the distance B1 between the center of the reel and the printing position can be made shorter than the conventional one. The overall size of the case body 19 can be reduced, and the ribbon cassette 18 can be reliably downsized.

Further, the ribbon cassette 1 having either of the features of improving the printing life or reducing the size described above.
Ribbon cassette 1 that has both features
The number may be eight, and is not particularly limited to this embodiment, and may be determined according to the design concept of the ribbon cassette 18.

The shape of the bottom portion 21 of the recess 20 is as follows.
As shown in FIG. 2, the top portion having a substantially roof shape may be provided with a linear portion 22 parallel to the longitudinal direction of the case body 19, and the present invention is not particularly limited to this embodiment.

FIG. 3 is a plan view for explaining the construction of the main part of the second embodiment of the ribbon cassette of the present invention.

As shown in FIG. 3, the ribbon cassette 18a of this embodiment is the same as the conventional second ribbon cassette 1 described above.
a pair of reels 3 rotatably supported in a case main body 19a having substantially the same shape and the same size as that of a plane and a substantially rectangular shape, and five rotatably supported so as to face the ribbon path. A guide roller 5 is provided. The pair of reels 3 are formed in a substantially cylindrical shape, and desired ink ribbons 6 are wound from both ends on the outer peripheral surface of each reel 3.

Further, in the case main body 19a of the ribbon cassette 18a on the side facing the platen (not shown), two concave portions 20a, 20a are formed in which the above-mentioned slide type thermal head 12 as a print head is arranged. The thermal head 12 is disposed in the recess 20a on the left side of the drawing. Each of the concave portions 20a, 20a has a bottom portion 21a on the center side of the ribbon cassette 1a. Then, the intermediate portion of the ink ribbon 6 is led out in the recess 20.

The concave portion 20a has a depth D1 in the depth direction of the side surface on the outer side in the longitudinal direction shorter than the depth D in the depth direction of the conventional substantially straight bottom portion 14a shown by a broken line in the drawing. The ink ribbon 6 wound around the reel 3 has a roof-like shape having an inclination along the shape of the maximum winding diameter R1. The feature of the ribbon cassette 18a of the present embodiment is that the shape of the bottom portion 21a is different from the shape of the conventional linear bottom portion 14 shown by the broken line in the figure. Other configurations are the same as those of the second conventional ribbon cassette 1a described above.

With such a structure, the bottom portion 21a of the recess 20a of the ribbon cassette 18a, the size D1 in the depth direction of the side surface on the outer side in the longitudinal direction, and the size D1 in the depth direction of the conventional bottom portion 14a shown by the broken line in the drawing are also taken. The maximum winding diameter R1 of the ink ribbon 6 is reduced by making it shorter than the size D and having a roof shape having an inclination that follows the shape of the maximum winding diameter R1 of the ink ribbon 6 wound around the reel 3.
Can be made larger than the maximum winding diameter R of the conventional ink ribbon 6.

More specifically, the maximum winding diameter R1 of the ink ribbon is restricted by the conventional linear bottom portion 14a shown by the broken line in the figure even if the case body 19a of the same size as the conventional case is used. It is possible to surely make the diameter larger than the maximum winding diameter R of 6, and it is possible to extend the total length of the ink ribbon 6 and improve the printing life. Similarly, the distance A1 between the reels can be shortened, and the longitudinal direction of the ribbon cassette 18a can be shortened.

The ribbon cassette 18a of this embodiment is also used.
Since the conventional one can be used in common except for the length of the case body 19a and the ink ribbon 6, it is possible to reduce the economical burden and the development time for developing the ribbon cassette 18a, and to manufacture the ribbon cassette 18a. This has effects such as reducing the economic burden related to the above and the labor of parts management.

When the ink ribbon 6 having the same maximum winding diameter R as the conventional one is used, the distance A1 between the reels and the distance B1 between the center of the reel and the printing position can be made shorter than the conventional one. The overall size of the case body 19a can be reduced, and the ribbon cassette 18a can be reliably downsized.

Thus, the ribbon cassette 1 of this embodiment
Also by 8a, the same effect as that of the first ribbon cassette 18 according to the present invention described above can be obtained.

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

[0044]

As described above, according to the ribbon cassette of the present invention, the maximum winding diameter of the ink ribbon can be made larger than before without increasing the size of the case body of the ribbon cassette, thereby improving the printing life. In addition, it is possible to reduce the size of the ribbon cassette, and it is possible to surely reduce the size of the ribbon cassette.

[Brief description of drawings]

FIG. 1 is a plan view illustrating a configuration of a main part of a first embodiment of a ribbon cassette according to the present invention.

FIG. 2 is a plan view showing another example of the shape of the bottom of the recess of the first embodiment of the ribbon cassette according to the present invention.

FIG. 3 is a plan view illustrating a configuration of a main part of a second embodiment of a ribbon cassette according to the present invention.

FIG. 4 is a plan view illustrating a configuration of a main part of a conventional ribbon cassette.

FIG. 5 is a plan view illustrating a configuration of a main part of another example of a conventional ribbon cassette.

FIG. 6 is an enlarged plan view illustrating a configuration of a main part of still another example of the conventional ribbon cassette.

[Explanation of symbols]

 3 reel 3a take-up reel 3b delivery reel 6 ink ribbon 12 thermal head 18,18a ribbon cassette 19,19a case body 20,20a recessed portion 21,21a bottom A1 distance between reels B1 distance between reel center and print position D1 recessed portion Size in the depth direction of R1 Ink ribbon maximum winding diameter

Claims (1)

[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. The ribbon cassette according to claim 1, wherein the shape of the bottom of the recess is approximated so as to follow the shape of the maximum winding diameter of the ink ribbon wound around the reel.