JP2750870B2 - Thermal transfer recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording apparatus capable of transferring and recording a good image even on a recording medium having low smoothness.

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

In this recording method, generally, an ink ribbon coated with a thermal transfer ink containing wax as a main component and a recording paper are pressed against a platen by a recording head, and in this state, the recording head is selectively heated to apply to the ink ribbon. In this method, the thermal transfer ink is melted into an image pattern and is transferred and recorded on recording paper.

In this thermal transfer recording method, when the head pressure is excessively increased, the molten ink containing wax as a main component spreads on the recording paper and appears as bleeding of the image, or the molten ink penetrates deeply into the recording paper fibers and the image is formed. The concentration becomes insufficient. Therefore, in a conventional thermal transfer recording apparatus, the head pressure is generally set to about 500 gf / cm or less.

<Problems to be Solved by the Invention> In the thermal transfer recording method, there is a difference in image quality depending on the smoothness of the recording paper, or transfer is performed particularly when using a recording paper having low smoothness such as rough paper. The edge portion of the image is difficult to transfer clearly. Therefore, it has been considered to use an ink ribbon coated with an ink containing a material having a relatively high melt viscosity such as a resin as a main component instead of wax as a ribbon for rough paper.

However, the ink containing the resin or the like as a main component generally has a high film strength and is easy to spread, so that a recorded image may be chipped, an edge of an image may be poorly cut, and reproducibility of details may be poor. In order to improve the reproducibility of the image details, it is preferable to increase the ribbon pressing force of the recording head and to quickly peel off the ink ribbon from the recording paper after heating by the heating element.

For that purpose, the ink ribbon must be peeled off from the recording paper at the end of the substrate of the recording head, and as shown in FIG.
From the heating element array 13a must shorten the distance d ₁ to the end of the substrate 13b. However, a common electrode 13c for supplying electricity to the heating element array 13a is generally provided with a thickness of 1 to 2 μm between the heating element array 13a and the end of the substrate 13b. If the length is shortened, a voltage effect occurs when a large number of heating elements are energized, and the amount of generated heat varies depending on the number of heating elements that are energized simultaneously, resulting in a problem that image quality becomes unstable.

For this reason, the area of the common electrode can be increased by using a recording head having a shape as shown in FIG. Therefore, the above-mentioned problem of voltage drop can be solved.

When the head pressure is increased, as shown in FIG. 11, if the pressing force length l ₁ of the recording head 13 to the platen 14 in the heating element row direction is longer than the width l _{2 of the} ink ribbon 2, the ink ribbon The recording head 13 protruding from the width direction of the recording paper 15
And the recording paper 15 may be damaged.

In particular, when a recording head as shown in FIG. 4 is used,
Since the contact area on the platen at the time of pressing is smaller than when a recording head as shown in FIG. 10 is used, even with the same pressing force, the effective pressure becomes larger in the case of the recording head of FIG. The task becomes significant.

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

<Means for Solving the Problems> A means for solving the above-mentioned conventional problems is a thermal transfer recording apparatus that selectively heats a thermal transfer medium by a recording head to perform transfer recording on a recording medium. A recording head having a heating element that generates heat according to the end side of the substrate, a platen that the recording head presses through the thermal transfer medium and the recording medium, and the recording head is 300 gf /
pressing means for pressing the platen with a head pressure of not less than cm and not more than 1500 gf / cm, means for separating the thermal transfer medium heated by the recording head from the recording medium within a predetermined time, and a resin as a main component Winding means for supplying to the thermal transfer medium a winding force for winding a thermal transfer medium wider than a pressing width by which the recording head presses the platen, the ink having: An adjusting means for adjusting the thermal transfer medium according to the recording head pressing force by the means, and winding the thermal transfer medium with the winding force according to the recording head pressing force.

<Operation> According to the above means, the effective contact area between the thermal transfer medium and the recording medium at the time of recording can be increased, and the head pressure can be increased by the winding force according to the head pressure. The recording medium is elastically deformed, and the ink containing resin as a main component is adapted to the recording medium and comes into contact with a large area. Therefore, the extension of the ink when the thermal transfer medium is peeled off from the recording medium is reduced, and image chipping or the like hardly occurs.

Further, by providing the heating element of the recording head on the side surface of the end portion of the head substrate, the thermal transfer medium is quickly separated from the recording medium after heating by the heating element.

Further, since the width of the thermal transfer medium is wider than the width of the recording head pressing the platen, the recording head does not squeeze the recording medium.

In addition, in the configuration of the above-mentioned means, it is not necessary to increase the pressure particularly excessively, so that the configuration of the recording apparatus can be increased in strength and the output of the motor used in each portion of the recording unit so that the recording device can withstand higher pressure. It is no longer necessary to increase the size of the apparatus, and it is possible to prevent the apparatus from increasing in size and cost.

<Example> Next, an example in which the above-described means is applied to a serial type thermal transfer recording apparatus will be described.

(First embodiment)

FIG. 1 is an explanatory perspective view of a thermal transfer recording apparatus according to a first embodiment, FIG. 2 is an explanatory sectional view of a thermal transfer medium, and FIG.
FIG. 3B is an explanatory cross-sectional view of a recording unit during non-recording and during recording.

First, a schematic configuration of the entire apparatus will be described. An ink ribbon 2 serving as a thermal transfer medium is stored in a cassette 1, and the cassette 1 is removably mounted on a carriage 3. The carriage 3 is driven by a drive shaft 4 to a carriage shaft 5.
Is configured to be able to reciprocate along. When the carriage 3 moves in the direction of arrow A in FIG. 1, the ink ribbon 2 is fed out by a pair of conveying rollers 6 constituting a conveying means of the ink ribbon 2, and the recording head 7 heats the ink ribbon 2; The ink is transferred onto a recording medium (high-quality paper, rough paper, plastic sheet, or the like, hereinafter referred to as “recording paper”) 9 whose back surface is supported by a platen 8.
Further, the recording paper 9 is configured to be intermittently conveyed line by line in the direction of arrow B in FIG. 1 by conveying means (not shown).

 Next, the configuration of each section will be described in detail.

First, the cassette 1 comprises a lower case 1a and an upper cover 1b. Inside the lower case 1a, an ink ribbon 2 is wound around a supply reel 1c of the cassette 1, and an opening of the lower case 1a extends from the supply reel 1c. And is wound around the take-up reel 1d through the pair of transport rollers 6 once.

The ink ribbon 2 is formed by applying a heat transferable (heat melting property, heat softening property, heat sublimation property, etc.) ink containing a resin as a main component on a support in a layered form, preferably an ink containing an ionomer resin. Is used. The ionomer resin refers to a resin in which a main chain of a hydrocarbon has a side chain of a carboxyl group partially or completely neutralized with a metal ion or a quaternary ammonium ion. Among the various ionomer resins, those obtained by neutralizing a copolymer composed of an α-olefin such as ethylene and propylene and an α, β-unsaturated carboxylic acid with metal ions are 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 embodiment has an intermediate layer 2b, a first transfer layer 2c, and a second transfer layer on a support 2a.
2d are sequentially laminated. Specifically, the applicant filed a patent application
No. 62-146380 (filed on Jun. 12, 1987), wherein a polyester film having a thickness of 6 μm and a width of 8 mm is used as a support 2a, and an intermediate layer 2a and a first transfer layer are used.
2c and the second transfer layer 2d use the following components, respectively.

Next, a belt 4c stretched between pulleys 4a and 4b is connected to the carriage 3, and when a carriage motor 4d connected to the pulley 4a is driven, the carriage 3 is guided by a carriage shaft 5 to reciprocate. Is configured.

When the carriage 3 moves in the direction of arrow A in FIG. 3 (B), the conveying roller pair 6 conveys the ribbon 2 in the direction of arrow C by driving a motor (not shown), and the recording head 7 records the ribbon 2 and the recording. Platen 8 through paper 9
The ribbon 2 is sequentially fed from the supply reel 1c by sliding while pressing the ribbon.

Further, a winding motor 3a is provided at a predetermined position of the carriage 3.
And a take-up shaft 3c connected via a friction clutch 3b to engage the take-up reel 1d when the cassette 1 is loaded on the carriage 3 and to perform recording (when the carriage 3
(Movement in the direction of arrow D) only in the direction of arrow D. Thus, the ribbon 2 fed from the supply reel 1c is taken up by the take-up reel 1d.

 In FIG. 1, reference numeral 12 denotes a guide shaft of the ink ribbon 2.

An opening 3d is formed at the front of the carriage 3 at a position corresponding to the opening when the cassette 1 is loaded, and the recording head 7 is positioned at the opening 3d in the direction of arrow E in FIG. Are mounted so that they can swing up and down.

The recording head 7 has a head substrate as shown in FIG.
A glaze layer 7b is formed on the side end surface of 7a, and this glaze layer 7b
A plurality of heating elements 7c that generate and generate electricity according to the image signal are arranged in a line, and the heating element 7c selectively generates heat by applying a voltage between the individual electrode 7d and the common electrode 7e. . By providing the heating element array on the end face on the substrate side as described above, the ink ribbon 2 heated by the heating element 7c peels off the recording paper 9 in a short time of about several ms after heating.

In this embodiment, the recording head 7 has a glaze layer thickness of 44 μm, a heating element array having a dot density of 240 dots / inch, and as shown in FIG. 4, the distance d from the heating element 7c array to the end of the substrate side end face as shown in FIG. The one having a thickness of 200 μm is used.
As a result, the ink ribbon 2 is peeled off from the recording paper 9 before being conveyed by 200 μm after being heated by the heating element 7c.
It comes off from. In addition, if the distance until peeling after this heating is set to be about 300 μm or less,
The ink ribbon 2 heated by the heating element 7c comes off the recording paper 9 in a short time of about several ms after heating.

As shown in FIG. 5, the length l ₁ of the recording head 7 pressing the platen 8 is the width l ₂ of the ink ribbon ₂ (l ₂ = 8 m).
m) shorter than 6 mm.

The recording head 7 is configured to press down the ink ribbon 2 and the recording paper 9 by pressing down the head by a pressing means 10 during recording, and to press the platen 8 with a set pressure.

The platen 8 pressed by the recording head 7 is formed in a flat plate shape. In the present embodiment, a hard rubber having a hardness of 73 degrees is formed in a flat plate shape having a width of 6 mm, and this is mounted on a platen holder 8a. .

Next, as shown in FIGS. 1 and 3, the structure of the pressing means 10 is such that a bent head arm 10a is rotatably mounted on a bent portion by a shaft 10b, and one end 10a of the head arm 10a. _The recording head 7 is supported by 1 and a head arm 10
tension spring between the other end 10a _{2 of a} and the pressing arm 10c
10d is installed.

Further, one end of the pressing arm 10c is rotatably mounted on the shaft 10b, and the other end is a tension spring 10f.
, So as to be pressed against the outer periphery of the mosquito 10e.

Accordingly, when the cam 10e is rotated, FIG.
As shown in (B), the recording head 7 moves down and up. When the recording head 7 is lowered by 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 preferably set to be in a range of 300 gf / cm or more and 1500 gf / cm or less, more preferably 450 gf / cm or more and 1100 gf / cm or less, and still more preferably 600 gf / cm or more and 1100 gf / cm. Set as below.

The ink ribbon 2 is moved downstream of the recording head 7 in the transport direction of the ribbon 2 by the tension applying means 11,
That is, the tension on the winding side (hereinafter referred to as “front tension”)
) Can be changed. The configuration of the tension applying means 11 is such that the tension arm 11a is
The shaft 1b is rotatably mounted on the shaft, and one end thereof is provided with a moving roller 11c, and the other end is provided with a tension spring 11d. Further, the ribbon 2 includes a guide roller 12 and a tension arm 11a provided on a lower case 1a.
, And reaches the take-up reel 1d via the pair of transport rollers 6.

Therefore, the ribbon 2 is pulled upward in FIGS. 3A and 3B by the tensile force of the spring 11d, and a front tension is applied.

Further, a magnet 11e is attached to the tension arm 11a, and a Hall element 11f is attached to the lower case 1a near the magnet 11e. Thereby, the distance between the magnet 11e and the Hall element 11f, that is, the inclination of the tension arm 11a is detected, and the position of the tension arm 11a is controlled to be constant by controlling the rotation speed of the conveying roller pair 6 during recording. The ribbon 2 is configured to be given a predetermined front tension so that the ribbon 2 can be accurately separated from the recording paper 9.

Next, the operation when recording is performed using the thermal transfer recording apparatus having the above configuration will be described.

The recording head 7 is moved down, the platen 8 is pressed with the head pressure of 300 gf / cm to 1500 gf / cm via the ink ribbon 2 and the recording paper 9, and the carriage 3 travels in the direction of arrow A in FIG. 3 (B). At the same time, printing is performed by sequentially transporting the ink ribbon 2 in the direction of arrow C. At this time, the heat transferable ink is melted by the heat of the heat generating element 7 c which generates heat in accordance with the image signal, and adheres to the recording paper 9. Although this molten ink has a high viscosity because it contains a resin as a main component, the fibers of the recording paper 9 are elastically deformed due to a high head pressure, and the high-viscosity molten ink is adapted along the fibers to form a wide area. Contact by area. Further, since the heating element array is provided on the end face of the recording head 7 on the substrate side, the ink ribbon 2 heated by the heating element is separated from the recording paper 9 immediately thereafter.

Therefore, when the ink ribbon 2 is peeled from the recording paper 9, the length of the molten ink extending (extending like a syrup) when the molten ink and the non-melted ink break is reduced. In addition, transfer defects at the image edge portion hardly occur, and a high-quality image with sharp image edges can be obtained.

Further, since the ink ribbon 2 is formed wider than the length of the recording bed 7 pressing the platen 8 in the direction of the heating element row, the recording head 7 does not directly squeeze the recording paper 9 and the recording paper 9 No damage.

If the head pressure is excessively increased (above the set head pressure), the recording paper 9 is damaged even through the ink ribbon 2, and the molten ink penetrates deeply into the fibers of the recording paper 9, thereby reducing the image density. It is not preferable because it lowers.

〔Experimental result〕

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

Recording is performed on the following three types of recording paper 9 with a common test pattern by dividing the head pressure into the following 10 stages, and (1) the sharpness of the edge portion in the transferred image at that time;
(2) Length of ink extension, (3) Ink density, (4)
Each of the recording papers was examined for damage.

(1) Sharpness of Edges in Transfer Image The results of subjective evaluation of the sharpness of the edges of the transfer image when recorded on the bond paper A at the respective head pressures are as shown in FIG. there were.

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

As is clear from FIG. 6, the sharpness of the edge portion of the image sharply improves from a head pressure of around 300 gf / cm, and the image quality is remarkably improved around 400 gf / cm.
In the vicinity, the image quality was further improved. The image quality did not change much when the head pressure was further increased, and the improvement of the image quality reached a saturation range around 1000 gf / cm.

 The evaluation was common to other recording papers.

(2) Length of ink extension It is considered that the sharpness of the edge portion of the transferred image is greatly affected by the extension of the molten ink. Then, with respect to the bond paper A, the extension length of the ink with respect to the head pressure was observed by a high-speed video. The result was as shown in FIG.

As is clear from FIGS. 6 and 7, there is a correlation between the length of ink extension and the sharpness of the image edge portion. If the ink extension is long, the sharpness decreases and the image quality deteriorates. It can be seen that when the ink spread is short, the sharpness is increased and the image quality is improved.

The length of ink extension slightly varied depending on the smoothness of the recording paper, but the tendency with respect to the head pressure was common to all three types of recording paper.

(3) Recording Density Recording was performed on the bond paper A at each of the above head pressures, and the subjective evaluation of the recording density of the transferred image was as shown in FIG.

Note that the evaluation in FIG. 8 was performed when the evaluation when the head pressure was 300 gf / cm was 4.

As is apparent from FIG. 8, when the head pressure became 1200 gf / cm or more, a paper fiber appeared on the surface, and a phenomenon that the apparent ink density was reduced occurred.

(4) Damage to the recording paper Recording was performed on each recording paper with the respective head pressures, and it was examined whether or not each recording paper was damaged.
No damage was observed on each recording paper up to 00 gf / cm.

Even when the head pressure was set to 1500 gf / cm, no damage was observed in the bond papers A and B, but slight damage was observed in the embossed paper.

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

(5) Comprehensive evaluation The above evaluations (1) to (4) can be evaluated as shown in FIG.

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

Further, when the head pressure is set in the range of 450 gf / cm or more and 1100 gf / cm or more, it can be seen that a considerably good transferred image including the image density can be obtained.

Further, it can be seen that the best transferred image can be obtained by setting the head pressure at 600 gf / cm or more and 1100 gf / cm or less.

The resin that is the main component of the thermal transfer ink of the ink ribbon need not be limited to the one described in the above embodiment, and may be, for example, an acrylic resin, a low molecular weight polyester resin, a urethane resin, a styrene acrylic resin, or a polyamide resin. And the like can also be suitably used.

<Effect of the Invention> As described above, according to the present invention, an ink containing a resin as a main component is printed by being pressed by a recording head having a heating element array provided on an end surface on a substrate side at a high head pressure within a certain range, By winding the thermal transfer medium with a winding force corresponding to the pressure, a good image can be transferred and recorded even on a recording medium having low smoothness.

Further, by making the width of the thermal transfer medium wider than the length of the head pressing the platen, it is possible to perform stable recording without damaging the recording medium.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of a thermal transfer recording apparatus according to one embodiment of the present invention, FIG. 2 is an explanatory view of a ribbon configuration, and FIG.
(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 pressing width and the ink ribbon width of the recording head, and FIG. The graph which shows the evaluation of the sharpness of the edge part of No. 7,
FIG. 8 is a graph showing ink elongation, FIG. 8 is a graph showing ink density, FIG. 9 is a graph showing overall evaluation of a transferred image with respect to head pressure, and FIGS. 10 and 11 are explanatory diagrams of the prior art. . 1 is a cassette, 1a is a lower case, 1b is an upper cover, 1c 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 is a drive mechanism, 4a and 4b are pulleys, 4c is a belt, 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 is an individual electrode, 7e is a common electrode, 8
Is a platen, 8a is a platen holder, 9 is a recording paper, 10 is a pressing means, 10a is a head arm, 10b is a shaft, 10c is a pressing arm, 10d and 10f are springs, 10e is a cam, 11 is tension applying means, 11a is a tension applying means. A tension arm, 11b is a shaft, 11c is a moving roller, 11d is a spring, 11e is a magnet, and 11f is a Hall element.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshihiko Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Kosuke Yamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Makoto Takamiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hitoshi Kishino 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-62-169684 (JP, A) JP-A-62-29991 (JP, A) JP-A-59-97046 (JP, U)

Claims (1)

(57) [Claims] 1. A thermal transfer recording apparatus which selectively heats a thermal transfer medium by a recording head to perform transfer recording on a recording medium, wherein a heating element which generates heat in accordance with an image signal is arranged on an end side surface of a substrate. A recording head comprising: a platen that the recording head presses through the thermal transfer medium and the recording medium; and a pressing unit that presses the recording head against the platen with a head pressure of 300 gf / cm or more and 1500 gf / cm or less. Means for peeling the thermal transfer medium heated by the recording head from the recording medium within a predetermined time; and a pressure width including a resin-based ink and a pressure width at which the recording head presses the platen. Take-up means for supplying a take-up force for taking up a wide thermal transfer medium to the heat transfer medium; and an adjusting means for adjusting the take-up force in accordance with a recording head pressing force by the pressing means. When having a thermal transfer recording apparatus characterized by winding the thermal transfer medium in the retracting force in accordance with the recording head pressing force.