JP3129109B2 - Thermal transfer recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording apparatus for forming images and characters on a recording sheet by using an ink sheet and a recording sheet typified by a video printer or the like.

[0002]

2. Description of the Related Art A conventional thermal transfer recording apparatus will be described with reference to the drawings.

FIG. 6 is a front view of a conventional thermal transfer recording apparatus. In the figure, 1 is a recording paper, 2 is an ink sheet coated with ink on a thin strip film, 3 is a thermal head, 4 is a heating element provided on the thermal head, and 5 is a rubber around a metal cylinder. Reference numeral 6 denotes a sheet guide made of sheet metal. Reference numeral 7 denotes a drive unit provided on the thermal head 3 and formed of an IC or the like, and has a role of selectively energizing the heating element 4 to generate heat. The sheet guide 6 has a role of protecting the driving unit 7 from the outside and a role of guiding the ink sheet 2. 8 is a capstan, 9 is a pinch roller.
The capstan 8 is rotated by a driving force from a first driving source (not shown), and holds and transports the recording paper 1 together with the pinch roller 9. A recording paper conveying means is formed from the capstan 8, the pinch roller 9, and a first driving source (not shown). 10
Is a supply reel around which an unused ink sheet 2 is wound ;
Is a take-up reel for winding the used ink sheet 2 . The take-up reel 11 is rotated by a driving force from a second driving source (not shown). The take-up reel 11 and a second driving source (not shown) form a sheet conveying means. Reference numeral 12 denotes a guide formed of a bent sheet metal which is attached to the thermal head 3 and guides the ink sheet 2.

The operation of the conventional thermal transfer recording apparatus configured as described above will be described. During recording, the thermal head 3 is pressed against the platen 5 via the ink sheet 2 and the recording paper 1. The capstan 8 rotates counterclockwise in the figure by a first driving source (not shown), and the recording paper 1 held by the capstan 8 and the pinch roller 9 is transported to the left in the figure.
At the same time, the take-up reel 11 is driven by a second drive source (not shown).
Is rotated counterclockwise in the figure to wind up the ink sheet 2. In this manner, the ink sheet 2 is conveyed from right to left in the drawing with the supply reel 10 being upstream and the take-up reel 11 being downstream. In this state, the heating element 4 is energized to cause the heating element 4 to generate heat.
Is transferred onto the recording paper 1.

By performing the above operation, a desired image can be obtained on the recording paper 1.

[0006]

However, in the above configuration, the recording paper 1 is pressed against the sheet guide 6 via the ink sheet 2 due to its rigidity. Because of this,
The entire width of the ink sheet 2 is the sheet guide 6 and the recording paper 1.
To be in a state of being sandwiched. The ink sheet 2 heated by the heating element 4 partially extends near the heating element 4,
The upstream ink sheet 2 is about to be conveyed together with the recording paper 1 while being sandwiched between the sheet guide 6 and the recording paper 1.
At this time, the rotational load of the supply reel 10 acts as a back tension in the conveyance of the ink sheet 2 and the heating element 4
Has the function of absorbing the expansion of the ink sheet 2 generated in the vicinity of the ink sheet 2, but cannot absorb the expansion of the ink sheet 2 when the ink sheet 2 is strongly sandwiched between the sheet guide 6 and the recording paper 1. . In the case of the above conventional example, the ink sheet 2
Is stretched between the recording paper 1 and the sheet guide 6 over the entire width, so that the expansion of the ink sheet 2 is not absorbed. Therefore, as recording progresses, the ink sheet 2 is placed near the heating element 4.
The increased amount of is accumulated. FIG. 7 shows this state. When the accumulated elongation increases to some extent, the ink sheet 2 is conveyed to the heating element 4 in a slack state, and the recording operation is performed while the ink sheet 2 is bent. Since the transfer is not performed on the folds (wrinkles) of the ink sheet 2, there is a problem that a streak-shaped untransferred portion is generated on the recording paper 1 and the image quality is impaired.

The present invention has been made in view of the above problems, and provides a thermal transfer recording apparatus in which untransferred portions do not occur due to wrinkles.

[0008]

In order to solve the above problems, a thermal transfer recording apparatus according to the present invention comprises a recording paper, an ink sheet coated with ink, a thermal head having a heating element, a recording paper and an ink sheet. A platen, a recording paper conveying means for conveying recording paper, a sheet conveying means for conveying an ink sheet, and a sheet guide positioned upstream of the heating element to guide the ink sheet. On the side of the guide that contacts the ink sheet
A substantially elliptical shape whose major axis is substantially the conveyance direction of the ink sheet, or
Or a configuration having a substantially parallelogram-shaped projection.

Further, the thermal transfer recording apparatus of the present invention includes a recording paper, an ink sheet coated with ink, a thermal head having a heating element, a platen for sandwiching the recording paper and the ink sheet with the thermal head, and a recording paper. The thermal head is provided with a drive unit for selectively energizing the heating element, which is provided upstream of the heating element. has a protective cover is provided so that the driver does not contact with the ink sheet, generally conveying direction of the ink sheet a longitudinal axis on the side in contact with the ink sheet of protective cover
It has a configuration in which substantially elliptical or substantially parallelogram-shaped projections are provided.

[0010]

In the thermal transfer recording apparatus of the present invention, a plurality of projections are provided in a direction perpendicular to the direction of transport of the ink sheet, and the downstream side of the long axis is inclined to the outside of the sheet guide or the protective cover. It becomes.

Further, the thermal transfer recording apparatus of the present invention has a configuration in which the cross section of the projection is in the form of a drop having a curved portion having a large curvature on the downstream side.

[0013]

According to the present invention, only the projections provided on the sheet guide allow the recording paper to be pressed against the sheet guide via the ink sheet due to the rigidity of the recording paper. The ink sheet sandwiched between the sheet guide and the recording paper cannot absorb the elongation of the ink sheet generated in the vicinity of the heating element due to the heating caused by the back tension generated by the transport load on the upstream side. However, the ink sheet is sandwiched between the sheet guide and the recording paper only at the protrusions, and most of the ink sheets are not sandwiched between the sheet guide and the recording paper. Therefore, since the expansion of the ink sheet is absorbed by the back tension, it is possible to obtain a thermal transfer recording apparatus in which untransferred portions due to wrinkles do not occur.

Further, when the major axis of the projection is opened outward on the downstream side, a force is generated to spread the ink sheet in the width direction on the downstream side of the projection. The force to expand the ink sheet in the width direction tries to shrink the ink sheet in the transport direction, which is a direction perpendicular to the width of the ink sheet. Can be more effectively prevented.

Further, by making the cross section of the projection into a droplet shape with the downstream side having a large curvature, only a part of the downstream side of the projection contacts the recording paper with the sheet guide via the ink sheet. However, the ink sheet is also in contact with the upstream side of the protrusion having a gentle curvature. Therefore, the transport load due to the friction of the ink sheet with the protrusion increases, and the back tension increases. As a result, the elongation of the ink sheet is more easily absorbed, so that the occurrence of untransferred portions due to wrinkles can be more effectively prevented.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal transfer recording apparatus according to one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of the thermal transfer recording apparatus according to the first embodiment. 6 that are the same as those in FIG. 6 indicate the same components. Numeral 13 in the figure denotes a projection provided on the side of the sheet guide 6 that comes into contact with the ink sheet 2.

FIG. 2 is a view showing the sheet guide 6, which is a front view and a side sectional view. A plurality of protrusions 13 are provided,
The numbers 13a, 13b, 13c, 13d, and 13e are respectively assigned. When the above-mentioned five protrusions are not particularly distinguished, they are collectively referred to as protrusions 13. The protrusion 13 has a substantially elliptical shape, and its long axis is substantially in the conveying direction of the ink sheet 2. Except for the projection 13c located at the center of the sheet guide 6, the long axis of each projection is directed outward on the downstream side, and its inclination is the outermost projection 13a.
13e are large and are located on the inner side of these.
The inclinations of b and 13c are set small.

The operation of the thermal transfer recording apparatus having the above configuration will be described. The operation at the time of recording is the same as that of the conventional thermal transfer recording apparatus, and the thermal head 3 is pressed against the platen 5 via the ink sheet 2 and the recording paper 1. The capstan 8 rotates counterclockwise in the figure by a first driving source (not shown), and the recording paper 1 held by the capstan 8 and the pinch roller 9 is transported to the left in the figure. 2nd not shown at the same time
The ink sheet 2 is wound up by rotating the take-up reel 11 counterclockwise in FIG.
Thus, the ink sheet 2 is conveyed from right to left in the drawing with the supply reel 10 being upstream and the take-up reel 11 being downstream. In the above state, the heating element 4 is energized and the heating element 4
Is generated, and the ink applied to the ink sheet 2 is transferred onto the recording paper 1 by the heat.

A color image can be obtained by using an ink sheet on which three types of inks of yellow, magenta, and cyan are sequentially applied in approximately the same size as the recording screen. At this time, first, a yellow image is formed on the recording paper 1 with yellow ink. After the end of the yellow recording, the thermal head 3 is separated from the platen 5 by a power source (not shown). This state is shown in FIG. In the state of FIG. 3, the take-up reel 11 is rotated counterclockwise by a second drive source (not shown) to perform cueing of a portion of the ink sheet 2 where magenta is applied, and
By rotating the capstan 8 clockwise, the recording paper 1 is transported from left to right in the figure, and the cue of the recording paper 1 is performed.
After the cueing of the magenta portion of the ink sheet 2 and the recording paper 1 is completed, the thermal head 3 is pressed against the platen 5 again by a power source (not shown). In the same manner, magenta recording is superimposed on the yellow image in the same manner. After the magenta recording is completed, the thermal head 3 is separated from the platen 5, and the cyan portion of the ink sheet 2 and the head of the recording paper 1 are respectively located. Then, the thermal head 3 is pressed against the platen 5 again to record cyan. As mentioned above, yellow, magenta,
A color image can be obtained by superimposing cyan recording on the recording paper 1.

Here, as is apparent from FIG. 1, the ink sheet 2 is sandwiched between the projections 13 and the recording paper 1, but the contact area is very small. Further, the protrusion 13 is not provided over the entire width of the sheet guide 6 as shown in FIG.
It occupies only a part of the width direction. Therefore, the back tension caused by the transport load of the upstream ink sheet including the rotation load of the supply reel 10 absorbs the expansion of the ink sheet that has expanded near the heating element 4 due to the heating.

Further, except for the projection 13c located at the center of the sheet guide 6, the long axis of each projection is directed outward at the downstream side, so that the ink sheet 2 is intended to spread in the width direction downstream of the projection 13. Force is generated. The force to expand the ink sheet 2 in the width direction tends to shrink the ink sheet 2 in the transport direction, which is a direction perpendicular to the width, and thus has a function of further absorbing the expansion of the ink sheet 2.

The reason why the projections 13a and 13e are larger on the downstream side than the projections 13b and 13c located on the inner side of the projections 13b and 13e is that the ink sheet 2 is widened in the width direction over the entire width. This is because the outer part of 2 needs to be pulled further outward than the inner part.

As described above, according to the present embodiment, the sheet guide 6
By providing the projections 13 on the surface, it is possible to obtain a thermal transfer recording apparatus that prevents the occurrence of untransferred portions due to wrinkles.

The height of the projection 13 is 0.5 mm to 1 m.
m. Further, the shape of the projection may be a substantially parallelogram as shown in FIG. FIG. 4 is a front view of the sheet guide according to the second embodiment of the present invention. The side sectional view is shown in FIG.
It is similar to that of The number 14 in the figure is a projection. In this case, the area where the recording paper 1 comes into contact with the sheet guide 6 via the ink sheet 2 increases, so that the recording paper 1
4 has the advantage that the surface of the recording paper 1 is less likely to be scratched.

Further, the cross section of the projection may be shaped as shown in FIG. FIG. 5 is a front view of a main part of the third embodiment of the present invention. Numeral 15 in the figure is a projection, and the downstream side is a drop-shaped cross section having a curve with a large curvature. In this shape, the recording paper 1 comes into contact with the sheet guide 6 via the ink sheet 2 only at a portion on the downstream side of the projection 15, but the ink sheet 2 also comes into contact with the upstream side of the projection 15 having a gentle curvature. . Therefore, the transport load due to friction with the protrusion 15 of the ink sheet 2 increases, and the back tension increases. As a result, the expansion of the ink sheet 2 is more absorbed, so that it is possible to effectively prevent the occurrence of untransferred portions due to wrinkles.

In this embodiment, the thermal head moves and presses and separates from the platen. However, there is no problem if the thermal head is fixed and the platen moves.

Further, in this embodiment, the sheet guide 6 also serves as a protective cover for protecting the drive unit 7, but may have independent configurations.

[0029]

As described above, the thermal transfer recording apparatus of the present invention comprises a recording paper, an ink sheet coated with ink, a thermal head having a heating element, and a platen which sandwiches the recording paper and the ink sheet with the thermal head. A recording sheet conveying means for conveying the recording paper, a sheet conveying means for conveying the ink sheet, and a sheet guide positioned upstream of the heating element to guide the ink sheet, and the sheet guide contacts the ink sheet. With the long axis on the side
By providing the substantially elliptical or substantially parallelogram-shaped projections in the feeding direction, the occurrence of untransferred portions due to wrinkles can be prevented with a simple configuration, and a high-quality image can be obtained.

Further, the thermal transfer recording apparatus of the present invention includes a recording paper, an ink sheet coated with ink, a thermal head having a heating element, a platen for sandwiching the recording paper and the ink sheet with the thermal head, and a recording paper. The thermal head is provided with a drive unit for selectively energizing the heating element, which is provided upstream of the heating element. has a protective cover is provided so that the driver does not contact with the ink sheet, generally conveying direction of the ink sheet a longitudinal axis on the side in contact with the ink sheet of protective cover
By providing a substantially elliptical or parallelogram-shaped projection, the unprotected portion due to wrinkles can be prevented by a low-cost method because the protective cover and the sheet guide are also used. Can be obtained.

In the thermal transfer recording apparatus according to the present invention, the projection is formed in a substantially elliptical shape or a substantially parallelogram shape whose major axis is substantially in the conveying direction of the ink sheet. It is possible to prevent the occurrence of untransferred portions due to wrinkles, which makes it possible to obtain high-quality images. This effect is particularly remarkable in the case of a substantially parallelogram shape.

Further, the thermal transfer recording apparatus of the present invention has a configuration in which a plurality of projections are provided in a direction perpendicular to the direction of transport of the ink sheet, and the downstream side of the long axis is inclined to the outside of the sheet guide or the protective cover. By doing so, a force for extending the ink sheet in the width direction is generated, so that the expansion of the ink sheet is absorbed, and the generation of untransferred portions due to wrinkles can be more effectively prevented, and a high-quality image can be obtained.

In the thermal transfer recording apparatus according to the present invention, the cross section of the projection is formed in the form of a drop having a large curvature on the downstream side, so that the contact between the ink sheet and the sheet guide is increased. Since the transport load increases, the occurrence of untransferred parts due to wrinkles is more effectively prevented,
High quality images can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a thermal transfer recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a front view and a side sectional view of a sheet guide according to the embodiment.

FIG. 3 is a front view illustrating the operation of the thermal transfer recording apparatus in the embodiment.

FIG. 4 is a front view of a sheet guide according to a second embodiment of the present invention.

FIG. 5 is a front view of a main part according to a third embodiment of the present invention.

FIG. 6 is a front view of a conventional thermal transfer recording apparatus.

FIG. 7 is a view for explaining expansion of an ink sheet of a conventional thermal transfer recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording paper 2 Ink sheet 3 Thermal head 4 Heating element 5 Platen 6 Sheet guide 7 Drive part

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-110183 (JP, A) JP-A-2-281967 (JP, A) JP-A-2-1286843 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B41J 2/32-2/325 B41J 2/335 B41J 17/30 B41J 35/04

Claims (4)

(57) [Claims] 1. A recording paper, an ink sheet coated with ink, a thermal head having a heating element, a platen sandwiching the recording paper and the ink sheet between the thermal head, and a recording paper for transporting the recording paper conveying means, and a sheet conveying means for conveying said ink sheet, said than heating element positioned upstream provided sheet guide for guiding the ink sheet, the length on the side in contact with the ink sheet of said sheet guide Move the ink sheet around the shaft
A thermal transfer recording apparatus provided with a substantially elliptical or substantially parallelogram-shaped projection in the feeding direction . 2. A recording paper, an ink sheet coated with ink, a thermal head having a heating element, a platen sandwiching the recording paper and the ink sheet between the thermal head, and a recording paper for transporting the recording paper The thermal head is provided with a drive unit for selectively energizing the heating element upstream of the heating element. Is provided with a protective cover so that the driving section does not contact the ink sheet, and a long axis is provided on a side of the protective cover that contacts the ink sheet.
Is substantially elliptical in the direction of transport of the ink sheet, or
A thermal transfer recording apparatus provided with a projection having a substantially parallelogram shape . 3. A method according to claim 1, wherein a plurality of said projections are provided in a direction perpendicular to a direction in which said ink sheet is conveyed, and a downstream side of said long axis is inclined to an outside of said sheet guide or said protective cover. The thermal transfer recording device according to claim 1 or 2 . Wherein the cross section of said protrusion claims, characterized in that the dripping-shaped downstream side is a large curve curvature
Item 3. The thermal transfer recording apparatus according to Item 1 or 2 .