JPH02235768A - Heat sensitive transfer recording method and apparatus therefor - Google Patents

Abstract

PURPOSE:To freshly print in high density at a high speed even on a medium to be recorded such as a rough sheet by temporarily transferring a transfer image corresponding to an image on an intermediate transfer medium between a heat sensitive recording head and a heat sensitive transfer recording medium, and further transferring the transferred image to the medium to be recorded. CONSTITUTION:An ink supply roll 1 is related by the rotation of its shaft 7 to feed a sheet 3 to a pressing roll 4A. The roll 4A is rotated by the rotation of its shaft 8A, and a platen roll 4B attached to a shaft 8B is rotated reversely to the rotation of the roll 4A. A recording sheet 5 is fed by the rotations of the. rolls 4A, 4B, the sheet 3 is fed, and wound on a winding shaft 10. The heat generator of a head 2 is selectively heated in dot state by a driving IC in a first transfer unit 11, the ink of the roll 1 is transferred to the sheet 3, the transferred image is further transferred from the sheet 3 to the sheet 5 in a second transfer unit 12 to print the sheet 5. This retransfer is performed by strongly pressing the sheet 3 to the sheet 5.

Description

[Detailed description of the invention] a. INDUSTRIAL APPLICATION FIELD The present invention relates to a thermal transfer recording method and apparatus.

mouth. BACKGROUND ART Conventionally, impact type wire dot printers and the like have been used as printers, but although these impact type printers are capable of high-speed printing, they have the disadvantage that the impact sound is unpleasant to the ears.

Therefore, attention is being paid to thermal transfer recording methods, which produce quieter sounds during printing. The thermal transfer recording method is a method in which ink from a thermal transfer medium is transferred onto a transfer medium using heat from a thermal recording head to print.

However, in the case of such a thermal transfer recording method,
The printing speed is slower than the impact method, and if the recording paper is rough paper, it is difficult for ink to adhere to it, making it difficult to print clearly and with high density.
Thermosensitive recording media are wasteful because the ink in the recording area bleeds off after one use, making them disposable and uneconomical.

C. Purpose of the Invention The purpose of the present invention is to provide an economical and reusable heat-sensitive recording medium that is quiet when printing, can print clearly and with high density even on recording materials such as rough paper, and is capable of printing at high speed and with high density. An object of the present invention is to provide a thermal transfer recording method and a device thereof.

two. Structure of the Invention The first invention is a thermal transfer recording medium (for example, an ink supply roll 1 (described later) (Fig. 1,
When thermally transferring an image from the image (e.g., Fig. 2) onto a recording medium, a transfer image corresponding to the image is once transferred onto an intermediate transfer medium between a thermal recording head and the thermal transfer recording medium;
Furthermore, the present invention relates to a thermal transfer recording method for retransferring this transferred image onto the recording medium.

The second invention includes a first transfer section constituted by a thermal recording head that is positioned opposite to each other with an intermediate transfer medium in between, and a thermal transfer recording medium that can be used multiple times at the same location, and this first transfer section. The present invention relates to a thermal transfer recording apparatus having means for guiding the recording medium from the first transfer section to the second transfer section, and for bringing the recording medium into contact with the intermediate transfer medium.

Ho. Example Examples of the present invention will be described below.

Thermal transfer recording is roughly divided into two methods: a line method and a serial method. In the line method, a thermal recording head (hereinafter referred to as
Simply called the head. ) does not move, and the head has a large number of heat generating parts (for example, about 24) located in a line perpendicular to the direction in which the recording paper is fed. One line is printed at the same time, and then the recording paper and ink sheet are fed by one line before the next line is printed. In the serial method, the head has a large number of heat generating parts (for example, about 50) arranged in a line with the width of one line in the direction along the recording paper feeding direction, and the head is positioned perpendicular to the recording paper feeding direction. One line is printed from the ink ribbon to the recording paper while moving in the direction, and then the recording paper is sent to the position of the next line, and the head retreats and returns to the original position, printing the next line. is now being done.

First, an example in which the present invention is applied to line type thermal transfer recording will be described.

FIG. 1 is a schematic perspective view showing the main parts of a line type thermal transfer recording apparatus.

For example, a cylindrical ink supply roll (thermal transfer medium) 1 made of a nonwoven fabric impregnated with thermal ink (solid at room temperature) and wound around a shaft 7 and a head 2 face each other to form a first transfer section 1.
1 is configured. Each component constituting the head 2 is not shown. Between the ink supply roll 1 and the head 2 is a thin sheet (intermediate transfer medium) 3 made of heat-resistant resin such as polyimide, polyethylene terephthalate, or metal.
The head 2 presses the sheet 3 against the ink supply roll 1 during printing. The front side of the sheet 3 is wound on the take-up shaft 10, and the rear side is wound on the feed-out shaft 10A. The pressure roll 4A is made of heatable rubber and has a built-in heater.
It is arranged so that it is hung on the winding shaft and wound up on the winding shaft in 10 days.

A cylindrical platen roll 4B made of rubber is located opposite the pressure roll 4A, and a second transfer section 12 is configured.

A recording plate 5 is located between the platen roll 4 and the sheet 3, and the sheet 3 and the recording plate 5 are brought into close contact with each other by pressing the platen roll 4 with the press roll 4A.

The ink supply roll 1 is rotated by the rotation of its shaft 7,
The sheet 3 is sent out to the press roll 4A.

The press roll 4A is rotated by the rotation of its shaft 8A, and the platen roll 4 attached to the shaft 8 rotates in the opposite direction to the rotation of the press roll 4A. Press roll 4
By the above rotation of A and the platen roll 4B, the recording paper 5
At the same time, the sheet 3 is sent out and the winding shaft 10
It is wound up.

In the first transfer unit 11, the heat generating part of the head 2 is selectively heated in dots by the driving IC, and the ink supply roll 1
The ink is transferred to the sheet 3, and this transferred image is retransferred from the sheet 3 to the recording paper 5 at the second transfer section 12, and printing is performed on the recording paper 5. This retransfer is performed by strongly pressing the sheet 3 against the recording pad 5.

Transfer in the first transfer section 11 will be explained with reference to FIG. 2, which is a cross-sectional view of this portion. In FIG. 2, the thickness of the sheet 3 and the size of the ink 6 attached to the sheet 3 are greatly exaggerated (the same applies to FIG. 3, which will be described later). The rotation of the shaft 7 causes the ink to be directed upwards in the drawing. At the point where the ink supply roll 1 contacts the sheet 3, the ink is selectively softened or melted by the selective heat generation of the heat generating part of the head 2, and this ink is transferred to the sheet 3. The ink 6 is deposited on the sheet 3 to form a transferred image. Since the ink supply roll 1 rotates in contact with the sheet 3 and is located on the opposite side of the head 2, continuous ink supply is possible.

This transferred image is retransferred onto the recording paper at the second transfer section 12. This retransfer will be explained with reference to FIG. 3, which is a sectional view of the second transfer section 12. Due to the pressure of the press roll 4A in the direction of the arrow and the rotation of the press roll 4A and the platen roll 4, the sheet 3 and the recorder 5, which are in line contact with each other, are sent in the direction of the arrow, respectively. At the position of contact with the recording sleeve 5, the ink 6 that had formed the transferred image on the sheet 3 is retransferred onto the recording sleeve 5 by the pressing force of the pressure roll 4A. To ensure this retransfer, the pressure roll 4A
It is desirable that a heater 13 be disposed inside to heat the ink 6 on the sheet 3 to soften or melt it. In particular, the above heating is necessary for retransfer to rough paper. In this way, an image is recorded (printed) on the recording paper 5 by retransfer, and there is no more ink on the sheet 3 after the retransfer. In addition, in case the ink is not completely retransferred and a small amount of ink remains on the sheet 3, move the cleaning blade 14 (a fur brush may be used) shown by the imaginary line to the sheet 3.
The seat 3 may be cleaned by pressing it against it.

The number of times that the same dot location on the ink supply roll 1 could be repeatedly transferred by the first transfer unit 11 was 10 times.

In the first transfer section 11, instead of the ink supply roll 1, as shown in FIG. The sheet 3 is rotated by the rotation of one pulley 57A over the 57th day, and the sheet 3 is pressed against the other pulley 57B by the pressing force of the head 2, and the ink 6 is supplied from the ink supply belt 51 to the sheet 3. It may also be transcribed.

Next, an example in which the present invention is applied to serial type thermal transfer recording will be described.

FIG. 5 is a schematic perspective view showing the main parts of a serial type thermal transfer recording apparatus.

Head 22, three ink supply rolls 21Y, 21M,
21G, a pressure roll 24A, and a ribbon cassette 35 are mounted on a common carriage 36. The ink supply rolls have the same structure as the ink supply roll 1 in the above example, and 21Y supplies yellow ink, 21M supplies magenta ink, and 21C supplies cyan ink.

The pressure roll 24A also has the same structure as the pressure roll 4A in the above example, and is rotatably supported by a shaft 28A. The ink supply rolls 21Y, 21M, 21G and the pressure roll 24A are attached to the carriage 36 with their axes perpendicular.

FIG. 6 is an enlarged internal plan view of the ribbon cassette 35.

Both ends of a thin ribbon (intermediate transfer medium) 23 made of polyimide resin or metal are connected to a feeding hub 30A and a winding hub 3.
0E3, the ribbon 23 is fed out from the feeding hub 30A by rotation of a shaft 30D provided on the carriage 36 and fitted into the winding hub 30, and is fed out from the feeding hub 30A through five guide pins 4.
0 and run in the direction of the arrow. The ribbon 23 comes out of the ribbon cassette at the cutout part of the ribbon cassette 35,
Here, the head 22 and three ink supply rolls 21Y, 2
It is sandwiched between either one of 1M and 21C, and the head 2
2, an ink image is formed on the ribbon 23 in the same manner as in the previous example. Ink supply roll 21Y, 2
1M and 21C are rotatably supported by shafts 27Y, 27M and 27C, respectively. A first transfer section 31 is configured by the head 22 and the ink supply rolls 21Y, 21M, and 21G. In FIG. 6, the ribbon 23 is shown in a state where the ink from the ink supply roll 21C is transferred, but the head 22 is moved as shown by the arrow and is positioned opposite to either the ink supply roll 21Y or the 21st direction 121C. You can now choose from yellow, magenta, or cyan. 3
When printing in color and/or black, head 2
2 is provided facing each ink supply roll as shown by the imaginary line, and black printing can be performed by printing in three colors or by overlapping the three colors. For black printing, if a black ink supply roll is added and four heads 22 are provided to perform transfer using black ink, clearer printing can be achieved.

In the second transfer section 32, the platen roll 24 is positioned horizontally opposite the pressure roll 24A. The ribbon 23 to which the ink has been transferred in the first transfer section 31 is sandwiched between a pressure roll 24A and a platen roll 24B, and is pressed in the direction of an arrow against a recording wheel 25 that comes into contact with the platen roll 24, and is placed on the ribbon 23. The ink image is retransferred onto the recording paper 25. In the second transfer section 32, the carriage 36 moves to the right in the figure while retransferring onto the recording paper 25. As the ribbon 23 moves in the direction of the arrow, the ribbon 23 and the recording paper 25 are The moving speed of the carriage 36 is adjusted to prevent them from rubbing against each other. When the ribbon 23 is completely wound around the take-up hub 30B, the shaft 30C provided on the carriage 36 and fitted into the feed-out hub 30A is rotated, and the ribbon 23 is run in the opposite direction of the arrow to be wound around the feed-out hub 30A. , used for the next print.

The transfer mechanism in the first transfer section 31 is the same as that shown in FIG. 2 in the above example. The retransfer mechanism in the second transfer section 32 includes a press roll 24A and a platen roll 24A.
This is the same as in the previous example shown in FIG. 3, except that B and B are located along directions perpendicular to each other. Press roll 2
It is preferable that the ink on the ribbon 23 is softened or melted at the time of retransfer by incorporating a heater in the ink 4A as in the above example. Also, instead of the pressure roll 24A,
A heat plate that slides against the non-inked surface of ribbon 23 without rotating can be used.

In FIG. 5, the carriage 36 includes pulleys PA, PB.
It is fixed to a rotating belt 39 and is guided by a guide bar 37 to reciprocate in the main scanning direction X. When the carriage 36 moves forward, the pressure roll 2
4A presses the ribbon 23 against the recording sleeve 25, and retransfer (printing) is performed while the ribbon 23 is fed out from the feeding hub 30A in FIG. 5 to the winding hub 30. Record G25
is in contact with the platen roll 24th by the pusher 38, and when printing for one line is completed, the press roll 24A and the ribbon 23 are separated from the recording paper, the carriage 36 moves backward, and the pulley moves at a predetermined angle on the 28th. By this rotation, the recording paper 25 is moved by one line in the sub-scanning direction Y. Printing is performed by repeating these operations.

The sheet 3 in FIG. 1 and the ribbon 23 in FIG. 6 may be in the form of an endless belt, as shown by imaginary lines in FIG. 6, and may be wound around pulleys or guide rollers. In this case, it is preferable to provide a tension pulley in order to apply appropriate tension to the sheet 3 and ribbon 23 to prevent them from loosening. In FIG. 6, the pressure roll 24A can be used as one of the boots.

In both the line method and serial method examples mentioned above, instead of printing directly on recording paper with a head as in the past, the ink image is first transferred to a sheet or ribbon as an intermediate recording medium. Since the ink image is retransferred onto the recording paper, the following unique effects can be achieved.

(1) 6 In the first transfer section, the ink supply roll is
Since the same location can be used many times, it goes without saying that running costs are lower than using conventional ink ribbons that can be used only once. Moreover, compared to the case of using a conventional ink ribbon that can be used multiple times (as explained later in FIG. 8, the ink layer is transferred to the recording paper by heating from the side of the ink carrying film carrying the ink layer with a head). hand,
In this example, since the ink supply roll is heated and transferred via a sheet or ribbon which is an intermediate transfer medium, the thickness of the ink supply roll can be increased. As a result, a large amount of printing can be performed with one ink supply roll. Therefore, the transfer method is fundamentally different from the case of using a conventional ink ribbon that can be used multiple times, and the above-mentioned effects can be achieved by this difference in the transfer method.

(2). In the first transfer section, the sheet or ribbon is not provided with an ink layer, and the first transfer is performed from the ink supply roll to the sheet or ribbon at the position where the ink supply roll and the sheet or ribbon come into contact. , high-speed recording is possible for the following reasons.

The first transfer mechanism will be explained using an example of the line method in FIG. The head 2 has the following structure. A heating element JW 42 made of tantalum nitride, for example, is adhered to an alumina substrate 46 supported by an aluminum substrate 47, and a common electrode 43 is provided at one end of the heating element layer 42, and a common electrode 43 is provided at the other end of the heating element layer 42. A large number of individual electrodes 44 are provided in a direction perpendicular to the plane of the paper, and the surface is covered with a wear-resistant protective layer 45 such as silicon nitride. Common electrode 43 and individual electrode 4
A heat generating portion 41 is formed at a position facing away from 4. By applying a selective electric signal to the individual electrodes 44 from a drive IC (not shown), the heat generating part 41 generates heat in a dot shape, and this heat heats the sheet 3 in contact with the heat generating part 41 in a dot shape. As explained in FIG. 2, ink 6 is transferred from the ink supply roll 1 onto the sheet 3 in the form of dots. Here, the thermal energy passes through the sheet 3 and is transmitted to the surface of the ink supply roll, so that heat is exchanged between the two in a short period of time, and therefore, the transfer is also performed in a short period of time. By selecting a durable material with high thermal conductivity and reducing the thickness of the sheet 3, the transfer speed can be increased.

In conventional thermal transfer recording, as shown in FIG. 8, an ink sheet 53 consisting of ink N 5 3 a and a polyethylene terephthalate (PET) film 53 b that temporarily holds the ink is transferred to the head on the ink carrying film 53 b side. 2 and comes into contact with the heat generating part 41 of No. 2. Then, the recording head 5 comes into contact with the ink layer 53a of the ink sheet, and is pressed against the platen roll 48 by the pressing force of the head 2. The ink layer 53a of the ink sheet 53 is transferred to the recording paper 5 in the form of dots due to the selective heat generation of the heat generating section 410, and the ink falls out at the position of the ink sheet where the ink 56 has been transferred.
The ink sheet 53 cannot be used for transfer again. The heat in the heat generating portion 41 passes through the ink layer 53a via the ink carrying film 53b, and the ink 56 that has become transferable due to this heat is transferred to the recording paper 5. Ink layer 53
a is thicker than the ink carrying film 53b, and therefore it takes a longer time to heat the ink N 5 3 a to the surface so that it can be transferred, compared to the structure shown in FIG.

(3) The ink supply roll mentioned in section (1) above can be used many times and no ink is wasted;
) As described in section 2, high-speed transfer is possible, and ink consumption can be reduced even during long periods of use (section (1)).
(running costs) are reduced.

(4). In the second transfer section, the contact pressure between the sheet or ribbon and the recording paper can be increased by increasing the pressing force of the pressure roll, making clear retransfer possible even when rough paper is used as the recording paper. Become. In the conventional method (FIG. 8), the ink sheet 53 has an extremely thin ink carrying film 53b carrying thick ink N 5 3 a, so it is not possible to increase the pressing force, and therefore the ink sheet 53 cannot be applied to rough paper. It is not possible to print clearly. Furthermore, with conventional ink ribbon types that are used multiple times, traces of previous printing called ghosts are recorded.

(5). In conventional thermal transfer recording, the ink ribbon or ink sheet after being subjected to recording has some ink removed from the transfer portion of the ink layer, so the recorded content can be determined by examining these.

Therefore, ink ribbons and ink sheets used for recording confidential documents and drawings cannot be disposed of, and people have to worry about how to dispose of them. In particular, the ink ribbon cannot be easily shredded with a shredder because it is wound around a sturdy hub inside the cassette, and if it is incinerated, the ink-carrying ribbon will generate high heat and damage the incinerator since it is made of PET. will give. The ink supply roll according to this example does not cause such problems when used repeatedly, and since ink can be resupplied, there is no need to dispose of it, and it is safe in terms of confidentiality. Its confidentiality is superior to conventional multiple ink ribbons and ink sheets.

Although the embodiments of the present invention have been described above, various modifications can be made to these examples based on the technical idea of the present invention. For example, in the serial system, the movement of the head 22 or the movement of the sheet 3
, the ribbon 23, the platen roll 4B, the driving of the 24th, the feeding of the recording sheets 5 and 25, etc., may be performed using other appropriate methods.

The platen roll 4th, 24B is also cylindrical, plate-shaped,
It may have an appropriate shape such as a polygon, or may be heatable. If it is possible to replenish ink to the ink supply roll or ink supply belt as described above, the apparatus may be provided with a heating means for melting the replenishment ink.

fart. Effects of the Invention In the present invention, a transferred image is once transferred onto an intermediate transfer medium between a thermal recording head and a thermal transfer recording medium (for example, the above-mentioned ink supply roll 1, etc.), and then this transferred image is transferred to a recording medium. Since the ink is retransferred onto the medium, during the first transfer, the heat generated by the thermal recording head is transmitted to the thermal transfer recording medium via the intermediate transfer medium, and the ink in this thermal transfer recording medium is transferred to the intermediate transfer medium. In addition to being able to continuously and repeatedly supply ink to thermal transfer recording media,
Image formation can be achieved efficiently by selecting the material and thickness of the intermediate transfer medium. As a result, unlike forming a transferred image directly on a recording medium using an ink sheet or an ink ribbon, no ink is wasted and high-speed recording is possible. Furthermore, when retransferring the transferred image onto the recording medium, the intermediate transfer medium can be strongly pressed against the recording medium, so that high-quality recording can be obtained regardless of the surface roughness of the recording medium. Also, since it is not an impact record, the record is carried out quietly.

[Brief explanation of the drawing]

1 to 7 show embodiments of the present invention. FIG. 1 is a schematic perspective view showing the main parts of a line type thermal transfer recording device. FIG. 2 is a thermal transfer recording device shown in FIG. 1. A schematic sectional view of the first transfer section of the device, FIG. 3 is a sectional view of the second transfer section, FIG. 4 is a schematic sectional view of the first transfer section according to another example, and FIG. 5 is a serial method. 6 is an enlarged internal plan view of the ribbon cassette of the thermal transfer recording device shown in FIG. 5, and FIG. 7 is a schematic perspective view showing the main parts of the thermal transfer recording device shown in FIG. FIG. 3 is an enlarged cross-sectional view of the transfer section of FIG. FIG. 8 is an enlarged sectional view of a transfer section of a conventional line type thermal transfer recording apparatus. In addition, in the symbols shown in the drawings, 1, 21Y, 21M, 21G... Ink supply roll 2, 22... Angry heat recording head 3...
...Sheet (intermediate transfer medium) 4A, 24A...
...Press roll 48,248...
・Flatten roller 5, 25...Recording paper 6...Transferred ink 11, 31...
......First transfer section 12, 32...
... Second transfer section 23 ... Ribbon (intermediate transfer medium) 35 ... Ribbon cassette 4
1... Heat generating section 51... Ink supply belt. Agent Patent Attorney Hiroshi Osaka Figure 1 Figure 7

Claims (1)

[Scope of Claims] 1. When an image is thermally transferred from a thermal transfer recording medium that can be used multiple times to a recording medium at the same location, an image is transferred onto an intermediate transfer medium between a thermal recording head and the thermal transfer recording medium. A thermal transfer recording method in which a transfer image corresponding to the image is once transferred onto the recording medium, and the transferred image is then retransferred onto the recording medium. 2. A first transfer section consisting of a thermal recording head that is positioned opposite to each other with an intermediate transfer medium in between, and a thermal transfer recording medium that can be used multiple times at the same location; a second transfer section that transfers a transfer image from the intermediate transfer medium to a recording medium; and a second transfer section that guides the intermediate transfer medium from the first transfer section to the second transfer section, and a A thermal transfer recording device having means for contacting and guiding a recording medium.