JPH01154787A - Base for electrothermorecording - Google Patents

Abstract

PURPOSE:To reduce a contact resistance or stabilize the contact resistance irrespective of recording speed, by a construction wherein at least a portion of a conductive fine powder mixed in a base is caused to protrude on the surface of the base on the side for contact with recording electrodes, and the conductive powder protruding on the surface provides secure contact with the electrodes. CONSTITUTION:A resistive base 11 comprises conductive carbon as a conductive fine powder 14 dispersed in a carrier 15, and at least a portion of the powder 14 protrudes on the surface of the carrier 15 on the side for contact with recording electrodes. The fine powder, when formed of a material lower in hardness than the recording electrodes, does not damage the recording electrode. A portion of the powder at the protruding part shaved by the recording electrodes secures further the contact between the electrodes and the base, and functions as a lubricant, thereby reducing the frictional resistance between the electrodes and the base. The fine powder, when formed of a material higher in hardness than the recording electrodes, secures contact with the electrodes, and shaves uniformly the surfaces of the electrodes for making contact with the base, thereby enabling all of the electrodes to be constantly maintained under the same conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a current-carrying recording support used in a current-carrying recording system.

(Prior art) Thermal transfer recording devices have features such as plain paper recording, noiseless printing, high reliability, and maintenance-free operation, and are suitable for personal computers,
It is widely used as an OA-related hard copy device such as a word processor printer or a color printer. However, it has been difficult to make high-quality records on papers with rough surfaces such as RPC paper and bond paper. Recently, an electric transfer type printer has been put into practical use, which allows high-quality recording even on paper with such a rough surface. The recording principle of this printer is shown in FIG. 1 is a resistive ink ribbon.

A resistive ink ribbon 1 has a resistive support 2 and a conductive M of AQ.
j3 and a coloring material layer 4 which is melted or softened by heat. 5 is a recording electrode. The recording electrode 5 is connected to a recording electrode drive circuit 6 that drives the recording electrode 5 according to a recording signal. A return electrode 7 is provided on the downstream side with respect to the direction of relative movement between the recording electrode 5 and the resistive ink ribbon 1 (indicated by the arrow ←). The return electrode 7 is grounded,
An ink ribbon transport drive means (not shown) engages the follower roller 8 to transport the resistive ink ribbon 1 . Due to the function of the recording electrode drive circuit 6, from the recording electrode 5,
A recording current is injected into the abutting resistive support 2 . The recording current flows through the resistive support 2, through the conductive layer 3 in the direction indicated by the arrow, and again through the resistive support to the return electrode 7.

Due to the Joule heat generated in the resistive support of the recording electrode 5 where the recording current is concentrated, the coloring material in the coloring material layer 4 in contact with the heat generating area is softened or melted and transferred to the recording paper 9 . Even under the recording electrode 7, the recording current passes through the resistive support 2 and generates Joule heat, but since the contact area is wider than that under the recording electrode 5, the temperature does not reach the point where the colorant layer 4 softens or melts. do not have.

From the above description, the recording electrode 5 moves on the resistive support 2 in the direction of the arrow ←, and injects a recording current into the resistive support 2 according to the recording signal, thereby transferring the coloring material 4. With this printer as is also obvious.

Since heat is generated within the ink ribbon 1, the efficiency of heat transfer to the color material layer 4 is good, compared to conventional thermal transfer recording printers that use a thermal head as an external heat source.

It is possible to use high-speed recording or coloring materials with high melting points and high sublimation points that could not be used in the past.

In this recording method, there are locations in the recording current path where heat is generated, that is, where resistance components exist, in addition to the locations mentioned above. The largest one is the contact resistance between the recording electrode 5 and the resistive support 2 of the resistive ink ribbon 1.

As the recording speed increases, that is, as the sliding speed of the recording electrode 5 on the resistive support 2 increases, the contact state between the two becomes unstable and the contact resistance increases. This increase in contact resistance is caused by an increase in the recording voltage, a decrease in printing quality due to insufficient recording current, and a decrease in the mechanical strength of the resistive ink ribbon due to heat generation at the contact surface between the recording electrode 5 and the resistive support.
This may lead to increased wear on the recording electrode.

As a method to solve these problems, a liquid (Japanese Patent Laid-Open No. 57-170796
) or carbon powder (USP 4,477, 19
8) to stabilize the contact, or a method of coating the surface of the resistive support with a stable thin film that is smooth and has an appropriate resistance value that does not cause crosstalk with adjacent recording electrodes (Proceedings of the
SID, voJ2.28. No. 1, PP8
7) has been proposed.

However, although these methods can suppress the increase in contact resistance during high-speed recording, the former method requires a mechanism for applying and supplying liquid or carbon powder, which complicates the device configuration. In the latter method, the ink ribbon configuration becomes complicated, so
There was a problem that the ink ribbon was expensive.

(Problems to be Solved by the Invention) As mentioned above, the conventionally considered methods require a mechanism for applying and supplying liquid or carbon powder, which complicates the equipment and makes the ink ribbon itself expensive. There were problems such as.

Therefore, this invention was made in view of the above-mentioned problems, and its purpose is to reduce the contact resistance between the recording electrode and the resistive ink ribbon or resistive recording paper, or to stabilize it regardless of the recording speed. The purpose of the present invention is to provide a resistant support that can

Another object of the present invention is to provide a resistive support capable of suppressing heat generation between a recording electrode and a resistive support of a resistive ink ribbon or a resistive recording paper.

Still another object is to provide an inexpensive resistive ink ribbon that has low contact resistance between a recording electrode and a resistive ink ribbon, and provides stable contact resistance regardless of the recording speed.

This invention relates to a resistive support made by mixing conductive fine powder into an insulating or appropriately conductive resin or paper, in which at least a part of the mixed conductive fine powder is brought into contact with a recording electrode. The conductive fine powder, which is protruded from the side surface and protruded from the support surface, ensures reliable contact with the recording electrode, thereby solving the above problem. Further, in a resistive ink ribbon in which an ink layer is provided on one surface of a resistive support, at least a part of the conductive fine powder mixed in the resistive support is made to protrude on the side on which the ink layer is not provided, The conductive fine powder protruding from the support ensures reliable contact with the recording electrode, thus solving the above problem. If a conductive fine powder that is softer than the recording electrode material is used, the frictional resistance will be reduced due to the lubrication effect, and if a hard fine powder is used, the recording electrode can be treated and all recording electrodes can be kept under the same conditions at all times.

(Function) The resistive support of the present invention or the resistive ink ribbon or resistive recording paper using the same can reliably maintain contact between the recording electrode and the resistive ink ribbon or the resistive recording paper. resistance is reduced.

Recording can be performed at a lower recording voltage than conventional methods.

Furthermore, since a constant contact resistance can be obtained regardless of the recording speed, printing without uneven density can be achieved. In addition, contact resistance is reduced, so there is almost no heat generation due to contact resistance.
Ribbon breakage due to mechanical strength deterioration of the ink ribbon is eliminated, and the life of the recording head is also extended. In addition, if comparatively soft conductive fine powder is used, the frictional resistance between it and the recording electrode will be reduced due to the lubrication effect, so that uneven feeding of the recording head and ink ribbon will be eliminated and beautiful printing will be obtained. Furthermore, since the wear of the recording electrodes is reduced, the life of the recording head is extended. The contact resistance between the recording electrode and the recording electrode can be reduced without adding any special means to the conventional device or using an expensive ink ribbon.

(Example) Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows the cross-sectional structure of a resistive ink ribbon according to the present invention. Resistant ink ribbon 10
are a resistive support 11, a conductive layer 12. It consists of an ink layer 13. The resistive support 11 is formed into a sheet by dispersing conductive carbon, which is a conductive fine powder 14, in a polyester resin, which is a carrier 15.

As shown in FIG. 1, this resistive support 11 is characterized in that a portion of the conductive fine powder 14 protrudes from the surface of the carrier 15 at least on the surface that contacts the recording electrode. . The height of this protrusion must be a height that does not cause vibration of the recording electrode or contact instability that causes uneven recording density, and is preferably about 2 μs or less. The conductive fine powder 14 is made of a material that is conductive and has a higher hardness than the recording electrode material, and the average particle size thereof is desirably about 2 μm or less, preferably 1 μm or less. In addition to conductive carbon black, copper, nickel, molybdenum, chromium, etc. can be used.

Fine powder made of a material with lower hardness than recording conductivity will not damage the recording electrode, and a part of the conductive fine powder in the protruding part that has been scraped off by the recording electrode will further spread between the recording electrode and the resistive support. It makes the contact more reliable and also acts as a lubricant, reducing the frictional resistance between the recording electrode and the resistive support. The fine powder made from a material harder than the recording electrode not only ensures contact with the recording electrode, but also uniformly scrapes the contact surface on the recording electrode's resistive support, making it possible to keep all recording electrodes under the same conditions at all times. do. career 15
In addition to polyester resin, polymers such as polycarbonate, polyvinyl chloride, and nitrocellulose, or paper can be used as the material. If the thickness of the resistive support 11 is too thick, the resistance value between the resistive support 11 and the conductive layer 12 will increase, resulting in a high recording voltage.If the resistive support 11 is too thin, the mechanical strength as a support for the ink ribbon IO will be insufficient. In order to
A range of about 20 .mu.s to several seconds is desirable.

The conductive layer 12 is formed by depositing AQ and has a thickness of 100 mm.
It is 0A. Since it serves as a return path for the recording current, a highly conductive material is suitable. If the thickness is too thick, cracks will easily occur and the role of the return path will become central, and if it is too thin, resistance will occur, so a range of 100A to 5000A is desirable.
The ink layer 13 is composed of carbon black as a coloring material, aliphatic ester resin, vinyl toluene/acrylic copolymer resin, and low melting point wax as binders. As the ink, either thermoplastic or heat sublimation ink can be used. Color pigments such as phthalocyanine blue, brilliant carmine 6B, and disazo yellow can also be used as coloring materials for thermoplastic ink. As the binder, thermoplastics such as polyimide, polyketone, and ethylene vinyl acetate, resins such as polystyrene and petroleum resin polyethylene, and waxes such as carnauba wax, paraffin wax, oxidized wax, and montan wax derivatives can be used. Color materials for sublimation ink include Color Index Solvent Blue 80 and Color Index Diverse Red 60.
・Dye with heat sublimation properties such as Color Index Yellow 7 can be used. As the binder, cellulose derivative-water-soluble acrylic starch or hydrophilic polymer resin can be used.

The thickness of the ink layer 13 is preferably 10 μs or less.

Next, a method for manufacturing this resistive ink ribbon will be explained. The resistive support 11 is composed of polyethylene terephthalate and conductive carbon having an average particle size of about 0.31 m in a weight ratio of 1.
0% of the mixture was mixed and kneaded well, and then stretched to form a film using a conventional method. The thickness of the film at this time was 61 m. A part of the mixed conductive carbon protruded from the surface of the film, and its average roughness (height) was about 0.1 μs. On one side of this film, 100 OA of i was applied by vapor deposition. Furthermore, a heat-melt ink containing 6% by weight of the aforementioned carbon black was applied thereon by heat-melt coating to obtain an ink layer with a thickness of 6 μs after solidification.

Printing was performed using this ink ribbon using a serial printer having a tungsten 8-electrode recording head, the recording principle of which is shown in FIG. For comparison, 100O of AQ was applied to a conventional resistive support without protrusions made of conductive fine powder.
Printing was also carried out using an ink ribbon with A applied thereon and the same ink applied to the same thickness.

Recording speed: 4 in/see, 6 in/sec, 8
As a result of printing on PPC paper at recording speeds of 10 in/see and 10 in/see, there was no noticeable difference between the two up to 6 in/see, but at a recording speed of 8 in/see, this invention No deterioration in print quality was observed with the new ink ribbon, but with the conventional ink ribbon,
Unevenness in density was observed. At a recording speed of 10 inches/see, bits were missing with conventional ink ribbons, but
With the resistive ink ribbon of this invention, no significant deterioration in print quality was observed.

In addition, when we compared the lifespan of the recording head for both ink ribbons by printing kanji characters continuously at a recording speed of 6 inches/see, we found that the conventional recording head.

1 million characters, but the ink ribbon of this invention had 1.5 million characters.

Next, only the recording head was changed to one with a copper recording electrode, and printing was performed at a recording speed of 81 nch/see. In the conventional ink ribbon, density unevenness and bit omission due to the same recording electrode occurred, but with the ink ribbon of the present invention, such problems did not occur and good printing was obtained. When the recording electrodes of the recording heads used for each ink ribbon were subjected to IIm, it was found that in the recording heads used for conventional ink ribbons, the condition of the recording electrode surface in contact with the resistive support differed depending on the recording electrode, causing bit dropouts. The recording electrode had deposits on it.

The contact surfaces of all the recording electrodes of the recording head using the ink repository of the present invention were almost the same, and no deposits were observed at all.

Next, FIG. 2 shows another electrical transfer serial printer using the ink ribbon according to the present invention.

In the figure, the recording head 16 has, for example, 50 tungsten recording electrodes (not shown) arranged in a vertical line at a density of 12 electrodes/Inl11, and is supported by a pair of head holders 17 and 18. A recording head assembly 19 consisting of a recording head 16 and head holders 17 and 18 is pressed against the platen 20 by a recording head biasing means (not shown) during recording, and is released from the pressed state during non-recording. The pressing force of the recording head 16 against the platen 20 needs to be appropriately strong because if it is too strong, the transferred characters may flow or the non-recording portions of the recording paper 21 may be stained.

The return electrode 22 is made of a grounded conductive roller and is arranged on the unused side of the resistive ink ribbon 23 when viewed from the recording electrode. The ink ribbon 23 is the ink ribbon according to the present invention described above. This ink ribbon 23 is housed in a ribbon cassette 24. A pair of pinch rollers 25 and 26 constitute an ink ribbon conveying means 6
Recording head assembly 19, return path electrode 22, ink ribbon transport means 25, 26, and ink ribbon cassette 2
4 is mounted on the carriage 27. Carriage 2
7 is guided by a guide bar 28, and the rotation of a carriage drive motor 29 is transmitted via a timing belt 30, thereby moving left and right along the platen 21. The platen 21 is rotated by the rotation of the platen driving motor 31 being transmitted via the timing belt 32 . The recording paper 21 is, for example, bond paper with a smoothness of about 10 seconds, is wound around the platen 20, and is transported by the rotation of the platen 20.

Next, the operation of this printer will be explained. carriage 27
In the initial state, the guide bar 28 is at the home position at the left end in the figure, and is moved to the recording start position in response to the recording start signal. During this time, the recording head 16 is pressed against the platen 20 by the recording head urging means, and the recording electrode, ink ribbon 23, recording paper 21, and platen 20 are brought into close contact with each other to form a recording region.

The carriage 27 moves to the right in the figure at a speed of about 10 inches/see while printing and recording in accordance with the recording start signal. At this time, the ink ribbon 23 is moved by the pinch roller 25,
26.

The recording current path and the ink transfer process to the recording paper 21 in this recording operation will be explained in detail with reference to FIG. The ink ribbon 23 and the recording paper 21 are supplied directly below the recording electrode 33 in the recording head 16, and these ribbons are pressed against each other to form a recording region. The recording portion t433 and the return electrode 22 move in the direction of arrow A on the surface of the resistive support 34 in the ink ribbon 23.

The recording electrode 33 is driven by a recording circuit 37 at a constant current according to a recording signal, and a recording current is injected into the resistive support 34 . Here, the recording electrode is driven with a constant current, but since the ink ribbon according to the present invention provides stable contact resistance, it can also be driven with a constant voltage. The injected recording current passes through the conductive layer 35 in the ink ribbon 23 as shown by arrow B,
It reaches the return electrode 22 through the resistive support 32 in the area contacting the return electrode 15 . At this time, since the recording current flows in a concentrated manner directly under the recording electrode 33, Joule heat is generated, which melts the ink layer 36 in this area and causes it to adhere to the recording paper 21. Joule heat is also generated in the resistive support 34 directly below the return electrode 22, but because the contact area of the return electrode 22 is large and the amount of heat per unit volume is small, the ink layer 36
It does not reach the point of melting the ink.

As shown in the figure, the resistive ink ribbon 23 of the present invention has protrusions 38 made of conductive fine powder on the surface of the resistive support 34 that is in contact with the recording electrode 33 and the return electrode 22. In this printer, the conductive fine powder protrusion 38 contacts the return electrode 22 before contacting the recording electrode 33.

This contact scrapes off a portion of the protrusions 38 and deposits them as an extremely fine conductive powder 39 on the surface of the resistive support 34 between the protrusions 38 . Therefore, under the recording electrode 33, the protrusions 38 are made smaller, and the extremely fine powder 3
9, the recording electrode 33 and the resistive support 34 are brought into contact with each other at a higher density. Due to this effect, this printer can print at a recording speed of 1/2 even on rough paper such as bond paper.
At 0 in/see, good printing was possible without uneven density or missing bits. Furthermore, when we checked the lifespan of the recording head by continuously printing Chinese characters, we found that it was possible to print about 2 million characters. When we conducted a similar continuous printing test of approximately 2 million characters using a conventional ink ribbon, the recording electrode was destroyed.
Several white streaks were observed.

Another example of an ink ribbon using a resistive support according to the present invention is shown in FIG. 4. Reference numeral 633 is a resistive ink ribbon, which includes a resistive support 34 on the surface of which a portion of conductive fine powder protrudes, and an ink layer. It consists of 35. One of the electrodes having the same shape is used as a recording electrode 36, and the other electrode is used as a return electrode 37, and current is applied between the two electrodes from the signal source 3B. The recording current flows as shown by arrow C.
Current concentrates on opposite ends of the circumferential electrodes, generating heat. This heat generation melts the ink and transfers it to the recording paper 39.

It is easily understood that when the resistive support according to the present invention is used in this type of ink ribbon, the same effect as that obtained with the ink ribbon shown in FIG. 3 can be obtained when compared with the conventional ink ribbon. Will.

Furthermore, paper may be used as the carrier. At this time, the conductive fine powder is mixed during paper making or sizing.

FIG. 5 shows an example of a recording method using a current-carrying recording paper 42 in which a thermosensitive color forming layer 41 is provided on a paper-based resistive support 40 according to the present invention. A thermosensitive color forming layer 44 under the recording electrode 43 is formed.

〔Effect of the invention〕

By utilizing the resistive support of the present invention in a recording material for current recording, high-speed recording becomes easy. In addition, high-quality printing without density unevenness is possible even during high-speed recording. In addition, since the contact resistance is small, the recording voltage can be reduced, and stable contact resistance can be obtained, making it possible to drive the recording electrode at a constant voltage, which could not be used even if density unevenness occurs, and simplifying the recording circuit. This makes it easy to integrate into IC. In the resistive ink ribbon according to the present invention, unnecessary heat generation due to contact resistance between the recording electrode and the resistive support is significantly reduced.
This eliminates thermal acceleration of wear on the recording electrodes, eliminates ink ribbon breakage that often occurs during high-speed recording, and extends the life of the recording head. In addition, the use of conductive fine powder that is softer than the recording electrode material also produces a lubricating effect, reducing the frictional resistance between the recording electrode and the resistive support, eliminating uneven feeding of the recording head and ink ribbon, and achieving high quality. It is possible to print.

It also extends the life of the head. The use of conductive fine powder that is harder than the recording electrode produces a treatment effect on the tip of the recording electrode, allowing the contact surface of the recording electrode with the resistive support to be kept clean at all times.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the configuration of a resistive ink ribbon according to the present invention, FIG. 2 is a diagram showing the configuration of an electrical transfer serial printer using the resistive ink ribbon according to the present invention, and FIG. The figure is a diagram for explaining the recording operation of the serial printer shown in Figure 2, and Figure 4 schematically shows the configuration and recording principle of another resistive ink ribbon using a resistive support according to the present invention. 5 is a diagram schematically showing the electrochromic recording paper using another resistive support according to the present invention and the recording principle, and FIG. 6 is a diagram showing the structure of a conventional resistive ink ribbon and its FIG. 2 is a diagram for explaining the recording principle of a printer using a printer. 10.23...Resistive ink ribbon 11.34.40...Resistive support 12...Conductive layer 13...Ink layer 14
...Electroconductive fine powder 15...Plastic carrier 38... Protrusion agent made of conductive fine powder Patent attorney Noriyuki Chika Yudo Yudo Motoyama Matsuyama Figure 3

Claims (1)

[Scope of Claims] A conductor is mixed in which is used in a recording method in which a resistive ink ribbon or a resistive recording paper is energized from a recording electrode and ink is transferred from the ink ribbon to the recording paper or directly recorded on the resistive recording paper. A support for energization recording, characterized in that a part of the mixed conductor protrudes from the surface of the support.