JPH0269252A - Thermal transfer recording apparatus - Google Patents

Abstract

PURPOSE:To record a good image even for a low smoothness recording medium without impairing the medium to be recorded by a method wherein ink having resin as a main component is recorded by pressing by high head pressure within a constant range with a recording head on a substrate side end surface of which a heating element line is established, and a width of a thermal transfer medium is made wider than a length by which the head presses a platen. CONSTITUTION:An ink ribbon 2 is formed by applying thermal transfer ink having resin as a main component in layers onto a base material. For a recording head 7, a glaze layer 7b is formed on a side end surface of a head substrate 7a, and a plurality of heating elements 7c which are heated by electrification are in a line arranged on this glaze layer 7b according to an image signal. The heating element 7c is selectively heated by impressing voltage between an individual electrode 7d and a common electrode 7e. A platen is pressed by a head pressure of 300gf/cm to 1,500gf/cm by making the recording head 7 down, and a carriage is travelled in the A direction. The ink ribbon 2 is successively conveyed in the C direction, and recording is performed. Further, a width of the ink ribbon 2 is formed wider than a heating element line direction length by which the recording head 7 presses the platen 8.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thermal transfer recording device capable of transferring and recording a good image even on a recording medium with low smoothness.

<Prior Art> Today, various recording methods have been developed as input information output devices, and a typical example is a thermal transfer recording method.

In this recording method, an ink ribbon and recording paper coated with a thermal transfer ink mainly composed of wax are pressed against a platen by a recording head, and in this state, the recording head selectively generates heat to apply the ink onto the ink ribbon. Thermal transfer ink is melted in an image pattern and transferred and recorded onto recording paper.

In this thermal transfer recording method, if the head pressure is excessively high, the molten ink mainly composed of wax will spread on the recording paper and appear as a smear in the image, or the molten ink will penetrate deeply into the fibers of the recording paper and cause the image to become blurred. The concentration will be insufficient.

Therefore, in conventional thermal transfer recording devices, generally 111
1. The head pressure is set at about 500 gf/cm or less.

<Problems to be Solved by the Invention> In the above-mentioned thermal transfer recording method, there may be differences in image quality depending on the smoothness of the recording paper, and especially when recording paper with low smoothness such as rough paper is used, the transfer The edge of the image
The transcription is bright and rough. Therefore, it has been considered to use an ink ribbon coated with an ink mainly composed of a material having a relatively high melt viscosity, such as a resin, instead of Wanx, as a ribbon compatible with rough paper.

However, inks containing the above-mentioned resins etc. as main components generally have strong film strength and are easy to spread, resulting in chipping of recorded images,
The edges of the image may be poorly cut and the reproducibility of details may be poor. In order to improve the reproducibility of image details, it is preferable to increase the ribbon pressing force in the recording head and to quickly peel the ink ribbon from the recording paper after heating with a heating element.

To do this, it is necessary to move the ink ribbon from the recording paper at the end of the substrate 13b to shorten the distance d1 from the heating element row +3a to the end of the substrate 13b, as shown in FIG. I have to throw it. However, from the heating element row 13a in 1j,! A common electrode 13c with a thickness of 1 to 2 μm is generally provided between the ends of the temporary 13b for supplying electricity to the heating element array 13a, and if the distance of this part is too short, a large number of heating elements may be connected to each other. When energized, a voltage effect occurs, and the heat generation V varies depending on the number of heating elements that are energized at the same time, resulting in unstable image quality.

Therefore, by using a recording head having a shape as shown in FIG. 4 in which heat generating element arrays are arranged in a line on the side surface of the end of the substrate, the area of the common electrode can be increased. Therefore, the above-mentioned voltage drop problem can be solved.

Furthermore, when the head pressure is increased, as shown in FIG. 11, if the pressing force length p: of the recording head 13 on the platen 14 in the direction of the row of heating elements is longer than the width β2 of the ink ribbon 2, the ink ribbon Gutter 13 to the record that protrudes from the width direction
presses the recording paper 15 with high pressure (this means that the recording paper 1
There were problems such as damage to the 5.

In particular, when using a gutter for recording as shown in Figure 4, the contact area on the platen during pressing is smaller than when using a recording head as shown in Figure 1O. In the case of the recording head shown in FIG. 4, the effective pressure is larger, so the problem described above becomes more pronounced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and provide a thermal transfer recording device capable of recording clear images even when using ink containing resin as a main component.

Means for Solving the Problems> Means for solving the conventional problems is a thermal transfer recording device that performs transfer recording on a recording medium by selectively heating a thermal transfer medium with a recording gutter, a recording head in which heating elements that generate heat in response to signals are arranged in a row on the side surface of an end of a substrate; a platen that the recording head presses through the thermal transfer medium and the recording medium; Thermal transfer includes a pressing means for pressing the platen with a head pressure of 300 gf/c+m or more and 1500 gf/cm or less, and ink containing resin as a main component, and has a width wider than the pressing width by which the recording head presses the platen. medium and 1
1; After heating the thermal transfer medium heated by the recording head in step 1, remove it from the recording medium before transporting 300μI11! ,
The feature is that a means for mowing the grass is provided.

<Operation> According to the above means, since the effective contact area between the thermal transfer medium and the recording medium during recording can increase the head pressure, the recording medium is elastically deformed and the ink containing resin as the main component can be increased. blends into the recording medium and comes into contact with it over a wide area. Therefore, when the thermal transfer medium is peeled off from the recording medium, the spread of the ink is reduced, and image defects and the like hardly occur.

Furthermore, by providing the heating element for recording on the side surface of the end of the head substrate, the thermal transfer medium can be quickly removed from the recording medium after being heated by the heating element. , I+ is released.

Furthermore, since the width of the thermal transfer medium is wider than the width at which the recording head presses the platen, the recording head does not squeeze the recording medium.

Furthermore, with the configuration of the means described above, there is no need to increase the pressure particularly excessively, so the configuration of the recording device must also increase the strength of each part so that it can withstand higher pressure, and the output of the motor used in each part of the recording unit. There is no need to increase the size of
It is also possible to prevent the equipment from increasing in size and cost.

<Embodiment> Next, an embodiment in which the above means is applied to a serial type thermal transfer recording device will be described.

[First embodiment]

FIG. 1 is a perspective view of a thermal transfer recording device according to the first embodiment, FIG. 2 is a cross-sectional view of a thermal transfer medium, and FIG.
B) is an explanatory cross-sectional view of the recording section during non-recording and during recording.

First, the general structure of the entire apparatus will be described. An ink ribbon 2 serving as a thermal transfer medium is housed in a cassette 1, and the cassette 1 is removably loaded into a carriage 3. Further, the carriage 3 is configured to be movable back and forth along a carriage shaft 5 by a drive mechanism 4. When the carriage 3 moves in the direction of arrow A in FIG. The ink is transferred onto a recording medium (such as high-quality paper, rough paper, or plastic sheet, hereinafter referred to as "r recording paper") 9 supported by a platen 8. Furthermore, the recording paper 9 is configured to be intermittently conveyed line by line in the direction of arrow B in FIG. 1 by a conveying means (not shown).

Next, the configuration of each part will be explained in detail.

First, the cassette l is composed of a lower case Ia and an upper cover 1b, and inside the lower case la, the ink ribbon 2 is wound around the supply reel lc of the cassette l, and from the supply reel lc to the opening of the lower case la. It is guided so that it is once exposed to the outside, and is wound around a take-up reel Id via a pair of conveying rollers 6.

The ink ribbon 2 is formed by applying a layer of thermally transferable (heat-melting, heat-softening, heat-sublimating, etc.) ink containing a resin as a main component onto a support, preferably an ink containing an ionomer resin. is used. The above-mentioned ionomer resin refers to one in which a side chain of a carboxyl group partially or completely neutralized with a metal ion or quaternary ammonium ion is attached to the main chain of a hydrocarbon. Among such ionomer resins, for example, a copolymer of an α-olefin such as ethylene or propylene and an αβ-unsaturated carboxylic acid, which is neutralized with metal ions, is used. The content of the ionomer resin in the thermal transfer ink component is preferably 5 to 70%.

As shown in FIG. 2, the ink ribbon 2 used in this example has an intermediate layer 2b, a first transfer layer 2c, and a second transfer layer 2d laminated in this order on a support 2a. Specifically, the applicant described this in Japanese Patent Application No. 146380/1983 (filed on June 12, 1988), and the support 2a has a thickness of 6p.
A polyester film having a width of 8fi was used, and the intermediate N2a, first transfer layer 2c, and second transfer layer 2d were each made of the following components.

Intermediate layer (1,0 trm) First transfer layer (2,2μ+11) Second transfer layer (1,2μl11) Next, the carriage 3 is connected to a heel 4c which is passed between pulleys 4a and 4b, and the When the carriage motor 4d connected to the pulley 4a is driven, the carriage 3
is configured to reciprocate while being guided by a carillon shaft 5.

When the carriage 3 moves in the six directions of arrows in FIG. By sliding the platen 8 while being pressed through the recording paper 9, the ribbon 2 is sequentially fed out from the supply reel lc.

Further, a winding motor 3a is provided at a predetermined position of the carriage 3.
and a winding shaft 3 connected via a friction clutch 3b.
c is provided, and is configured to engage with the take-up rule 1d when the cassette L is loaded into the carriage 3, and to rotate in the direction indicated by the arrow only during recording (when the carriage 3 moves in the direction indicated by the arrow 6). .

As a result, the ribbon 2 unwound from the supply reel 1c is wound onto the take-up reel 1d.

Note that 12 in FIG. 1 is the guide F axis of the ink ribbon 2.

Further, the front part of the carriage 3, the cassette 1
An opening 3d is formed at a position corresponding to the opening when the disc is loaded, and a recording head door is attached to the opening 3d so as to be swingable in the direction of arrow E in FIG.

The recording head 17 is connected to the head substrate 7 as shown in FIG.
A glaze layer 7b is formed on the side end surface of the glaze layer 7b, and a plurality of heating elements 7c are energized to generate heat according to the image name.
are arranged in a line, and the individual electrodes 7d and the common type J! 1i
The heating element 7C selectively generates heat by applying a voltage between the heating element 7e and the heating element 7e. By providing the heating element array on the substrate side end surface as described above, the heating element 7c is
The heated ink ribbon 2 comes to peel off from the recording paper 9 in a short time of about several milliseconds after heating.

In this embodiment, the recording head 7 has a glaze layer thickness of 44 μm, and a heating element array with a dot density of 240 dots/
As shown in FIG. 4, a 1-nch device is used in which the distance d from the row of heating elements 7c to the edge of the substrate side end is 200 μm. As a result, the ink ribbon 2 is heated by the heating element 7C and transported 200 pm from the recording paper 9. , 11, and the ink ribbon 2
comes to be separated from the recording paper 9 by 7.1j in a short time after heating. The distance until peeling after heating is approximately 300μ.
If it is set to be less than m, the ink ribbon 2 heated by the heating element 7C will peel off from the recording paper 9 in a short time of about several 11 seconds after heating.

Further, as shown in FIG. 5, the recording platen 7 is
The pressing length l is the width ff2 (j2
2 = 811) is composed of 6 dragons, which is shorter than 2 = 811).

During recording, the recording head door is configured to move its head down by a pressing means 10 to press the ink ribbon 2 and recording paper 9 into contact with each other, and to press the platen 8 at a set pressure.

The platen 8 pressed by the recording head 7 is formed into a flat plate shape, and in this embodiment, it is made of hard rubber with a hardness of 73 degrees and is formed into a flat plate shape with a width of 6 mm, which is attached to a platen holder 8a. There is.

Next, the configuration of the pressing means 10 is such that, as shown in FIGS.
The head arm 10 is rotatably pivoted by the head arm 10.
The recording gutter 7 is supported on one end 10a1 of the head arm 10a, and the other end 10a2 of the head arm 10a and the pressing arm 10c
A tension spring 10d is attached between them.

Furthermore, one end of the pressing arm lOc is rotatably attached to the shaft 1ob, and the other end is pressed against the outer periphery of the cam 10e by a tension spring lOf.

Therefore, when the cam lOe is rotated, the result is shown in FIG. 3(A).

As shown in (B), the recording head 7 moves head down and head up. Then, when the recording head 7 heads down due to the rotation of the cam 10e and pulls the spring 10d, the recording head 7 presses the platen 8 with a predetermined pressure. The head pressure at this time is 300gf/cm or more15
It is preferable to set it within a range of 00 gf/cm or less, more preferably 450 gf/cn+ or more and 1100 gf/cm or less, and even more preferably 600 gf/cm.
Set it to between cm and 1100 gf/cm.

Further, the ink ribbon 2 is applied by the tension applying means 11 to the downstream side of the recording head 7 in the conveying direction of the ribbon 2.
In other words, the tension on the winding side (hereinafter referred to as "front tension")
) is configured so that it can be changed. The configuration of this tension applying means 11 is as follows: tension arm lla
is rotatably attached to a shaft 11b, a moving roller llc is provided at one end thereof, and a tension spring lid is attached to the other end. Furthermore, the ribbon 2
is guided by a guide roller 12 provided in the lower case 1a and a moving roller llc of the tension arm lla,
It then passes through a pair of transport rollers 6 and reaches a take-up rule ld.

Therefore, the ribbon 2 is pulled upward in FIGS. 3(A) and 3(B) by the tensile force of the spring lid.
Front tension is applied.

Furthermore, a magnet lie is attached to the tension arm lla.
is attached to the lower case 1 near the magnetic eye 1e.
A Hall element 11f is attached to a. Thereby, the distance between the magnet lie and the Hall element Iff, that is, the inclination of the tension arm lla, is detected, and the rotational speed of the conveying roller pair 6 is controlled during recording, thereby controlling the position of the tension arm lla to be constant; The configuration is such that a constant front tension is applied to the ribbon 2 so that the ribbon 2 is accurately peeled off from the recording paper 9.

Next, the operation of recording using the thermal transfer recording apparatus having the above configuration will be explained.

The recording head 7 is head down and the platen 8 is set at 300 gf/cm to 150 gf/cm via the ink ribbon 2 and recording paper 9.
Press with a head pressure of 0 gf/cm, and move the caliper 3 to the third position.
The ink ribbon 2 is run in the direction of the arrow in FIG. At this time, the thermal transfer ink is melted and adhered to the recording paper 9 by the heat generated by the heating element 7C in response to the image signal. This molten ink has a high viscosity because its main component is resin, but
Due to the high head pressure, the fibers of the recording paper 9 are elastically deformed,
The high viscosity molten ink blends along the fibers and makes contact over a wide area. Further, since a heating element array is provided on the substrate side end surface of the recording head 7, the ink ribbon 2 heated by the heating element peels off from the recording paper 9 immediately after that.

Therefore, when the ink ribbon 2 is peeled off from the recording paper 9,
When the melted ink and the non-melted ink break, the length that the melted ink extends (extends like syrup) becomes smaller.

In addition, transfer defects at image edge portions hardly occur, and a high-quality image with sharp image edges can be obtained.

Furthermore, since the ink ribbon 2 is formed wider than the length in the row direction of the heat generating elements by which the recording pad 7 presses the platen 8, the recording pad 7 does not directly squeeze the recording paper 9, and the recording paper 9 will not be damaged.

Note that if the head pressure is set too high (beyond the set head pressure), the recording paper 9 will be damaged even through the ink ribbon 2, and the molten ink will penetrate deep into the fibers of the recording paper 9, causing the image density to deteriorate. This is not preferable because it reduces the

〔Experimental result〕

Next, the results of an experiment in which thermal transfer recording was performed by changing the head pressure using the apparatus of the first embodiment described above, and the recorded image was corrected will be shown.

Recording was performed on the following three types of recording paper 9 using a common test pattern with the head pressure divided into 10 levels as shown below, and at that time (1) the sharpness of the edge portion of the transferred image;
(2) Length of ink extension, (3) Ink concentration,
(4) Damage to each recording paper was verified.

(*The smoothness of embossed paper is so rough that it cannot be measured.) (1) Sharpness of the edges in the transferred image The results of subjective evaluation of the sharpness of the portions were as shown in FIG.

In the evaluation shown in FIG. 6, the evaluation was made as 3 when the head pressure was 300 gf/cm, and 4 when the head pressure was 1200 gf/cm.

As is clear from Fig. 6, the sharpness of the edge portion of the image varies from around 300 (Hf/cm) to 9
The improvement in image quality was remarkable at around 400gf/8m, and further improvement was seen at around 600gf/cm. Even if the head pressure was increased further, the image quality did not change much, and the improvement in image quality reached a saturation region around lo00gf/c+n.

Incidentally, the values mentioned in 3.) above were also common to other recording papers.

(2) Length of extension of ink It is considered that the sharpness of the edge portion of the transferred image is greatly influenced by the extension of the molten ink. Therefore, for bond paper, the length of ink extension relative to the head pressure was observed using high-speed video. The results were as shown in FIG.

As is clear from FIGS. 6 and 7, there is a correlation between the length of the ink and the sharpness of the image edge.
It can be seen that the longer the ink extends, the lower the sharpness and the lower the image quality, and conversely, the shorter the ink extends, the higher the sharpness, the higher the image quality.

Incidentally, although the length of the ink elongation differed slightly depending on the smoothness of the recording paper, the tendency with respect to the pressure was common to all three types of recording paper.

(3) Recording was performed on bond paper at the respective gutter pressures of T and 'A density P I, and the results of main evaluation of the recorded density of the transferred image were as shown in Figure 8. Ta.

In addition, the evaluation in FIG. 8 was performed with the evaluation when the henode pressure was 300 gf/cm as 4.

As is clear from Figure 8, the head pressure is 1200gf/
When the thickness exceeded cm, paper fibers appeared on the surface, resulting in a phenomenon in which the apparent ink density decreased.

(4) Damage to the recording paper When recording was performed on each recording paper using the above-mentioned respective head pressures and checking whether each recording paper was damaged, it was found that the head pressure was 12.
No scratches were observed on each recording paper up to 00 gf/cm.

Also, even if the pressure is set to 15008 f/cm, bond paper A
Regarding B, no scratches were observed, but some damage was observed on the embossed paper.

When the head pressure was further increased to 1700 gf/cm, one scratch was observed on each recording paper.

(5) Comprehensive evaluation If the evaluations of (1) to (4) above are combined, the evaluation can be made as shown in FIG. 9.

As is clear from FIG. 9, when the head pressure is set to 300 gf/cm or more and 1500 gf/0m or less for the heating element array, a good transferred image can be obtained even on recording paper with low surface smoothness. I understand.

Furthermore, the pressure in the duct is set at 450 gf/cm or more to 1100 gf.
It can be seen that when set within the range of /ci or less, a fairly good transferred image can be obtained, including the image density.

Furthermore, the bending pressure should be 600 gf/cm or more and 1100 gf.
It can be seen that the best transferred image can be obtained when the value is set to /cm or less.

It should be noted that the resin that is the main component of the thermal transfer ink of the ink ribbon is not limited to the above-mentioned examples.
In addition, for example, acrylic resin, low molecular weight fi polyester resin, urethane resin, styrene acrylic resin, polyamide resin, etc. can also be suitably used.

<Effects of the Invention> As described above, the present invention provides an ink containing resin as a main component.
By pressing and recording with a high head pressure within a certain range using a recording head equipped with a row of heating elements on the end surface of the substrate, good images can be transferred even to recording media with low smoothness! You can request it.

Furthermore, by making the width of the thermal transfer medium wider than the length at which the head presses the platen, the recording medium can be
This allows stable recording without causing long-term damage.

[Brief explanation of the drawing]

FIG. 1 is a perspective explanatory diagram of a thermal transfer recording device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the configuration of a ribbon, and FIG. 3 (A)
, (B) is an explanatory diagram of the recording operation, FIG. 4 is an explanatory diagram of the configuration of the recording head, FIG. 5 is an explanatory diagram showing the state of the press width of the recording head and the ink ribbon width, and FIG. 6 is an explanatory diagram showing the state of the press width of the recording head and the ink ribbon width. A graph showing the evaluation of the sharpness of the edge portion of the transferred image,
Fig. 7 is a graph showing ink elongation, Fig. 8 is a graph showing ink density, Fig. 9 is a graph showing comprehensive evaluation of transferred images with respect to hend pressure, and Figs. 1O and 11 are explanatory diagrams of prior art. It is. l is a center, 1a is a lower case, 1b is an upper cover, lc is a supply reel, 1d is a take-up reel, 2 is a ribbon, 3 is a carriage, 3a is a take-up motor 3b is a friction clutch, 3c is a take-up shaft, 4 4a and 4b are drive mechanisms, 4a and 4b are pulleys, 4c is a heald, 4d is a carriage motor, 5 is a carriage shaft, 6 is a pair of transport rollers, 7 is a recording head, 7a is a substrate, 7b is a glaze layer, 7c is a heating element, 7d are individual electrodes, 7e is a common electrode, 8 is a platen 1.8a is a platen holder, 9 is a recording paper, 10 is a pressing means, lOa is a helad arm, 10b is a shaft, 10c is a pressing arm, 10d
, 10f is a spring, 10e is a cam, 11 is a tension applying means, lla is a tension arm, llb is a shaft,
llc is a moving roller, lid is a spring, lie is a magnet,

Claims (1)

[Scope of Claims] A thermal transfer recording device that selectively heats a thermal transfer medium with a recording head to perform transfer recording on a recording medium, comprising a row of heating elements that generate heat according to an image signal on the side surface of an end of a substrate. a platen on which the recording heads press against the thermal transfer medium and the recording medium;
a pressing means for pressing the platen with a head pressure of less than cm; a thermal transfer medium containing ink containing resin as a main component and having a width wider than the pressing width by which the recording head presses the platen; and the recording head. A thermal transfer recording device comprising: a means for peeling a thermal transfer medium heated by a heating medium from a recording medium before the thermal transfer medium is heated and transported by 300 μm.