JPS60174664A - Recording head - Google Patents

Abstract

PURPOSE:To obtain a high-speed, high-quality full-color printer at low cost by a method in which in a recording head consisting of a conductive layer, an insulator layer and a recording electrode, the base plate formed by providing the recording electrodes on an insulating base plate is bonded to a metal plate to form a common electrode. CONSTITUTION:In a recording head 20, a recording electrode pattern 24 is formed on an insulating base plate 21 of ceramics, etc., by vapor deposition and photo-etching techniques. A recording electrode material 25 is provided by a selective plating on the pattern 24 to form a base plate 22, and the base plate 22 so formed is bonded to a conductive plate 6 of a metal, etc. A high-density recording head can thus be obtained with a highly accurate photo-etching technique on a mass production basis. As the insulating base material having a heat resistance, alumina-based ceramics and SiO2 and MnO-based steatite and forsterite are suitable. As the recording electrode material having a wear resistance, materials having a high hardness and capable of being plated, e.g., Ni-P, etc., are recommendable.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a recording head, and more specifically, the present invention relates to a recording head, and more specifically, the present invention relates to a recording head, in which a current is passed through a conductive sheet, heat is generated by Joule heat, melting the thermofusible ink, and transferring the ink to a transfer paper. The present invention relates to so-called electrical thermal transfer, in which printing is obtained by

[Prior art]

A method of melting solid ink using heat generated by electricity and transferring it to recording paper was devised, for example, as seen in Japanese Patent Application No. 51960/1984, in which a single head is scanned and a current is passed through a common electrode to record. has been done. However, since it had a single head, it was extremely slow and could not be put into practical use.

In addition, for sheets having a two-layer structure in which the conductive layer is a resistive layer and a conductive layer, a multi-head type has been devised, as seen in, for example, US Pat. No. 3,744,611.

However, in this case, since the conductive layer is used as a means for eliminating the spread of current, the purpose of the present invention, which is to perform area modulation for each pixel, cannot be achieved, as will be described later.

〔the purpose〕

The present invention eliminates the above-mentioned drawbacks, and its purpose is to realize a recording head that simultaneously drives multiple recording electrodes and still applies area modulation to each pixel, thereby achieving high speed and low cost. The goal is to realize a high-quality full-color printer.

〔overview〕

FIG. 1 shows the printing principle of the present invention. A current-carrying heating sheet 1 consisting of a resistance layer 2, a support layer 3, and a heat-melting ink layer 4 is stacked with a recording paper 8 made of plain paper, and a recording electrode 5 and a common electrode 6 are pressed against each other, and a voltage pulse is generated by a signal generator 7. When applied, a current flows from the recording electrode 5 through the resistive layer 2 to the common electrode 6. At this time, if the contact area of the common electrode 6 is sufficiently larger than that of the recording electrode 5, the electric field will be concentrated near the recording electrode, and the most Joule heat will be generated in this area. The generated heat passes through the support 3 by thermal conduction and melts the thermofusible ink 4, and the melted ink 10 is transferred onto the recording paper 8. At this time, the current flowing through the resistance layer 2 is widely distributed as shown in FIG. 2(a). Therefore, the heat generated in the resistance layer 2 due to this current is distributed in a mountain shape as shown in FIG. 2(b). The figure shows the temperature distribution on the X-Y line, and 11 is the case where the input energy is larger than 12. The vertical axis represents temperature, and if T8 is the melting point of the thermofusible ink, the area of the heat distribution cut by T8 changes depending on the input energy. In other words, the area of the printed dots is modulated by the applied energy.

In this case, as long as the resistance layer 2 is homogeneous, the electric field distribution will be similar for any energy, and recording dots with very good reproducibility can be obtained.

Moreover, since heat generation occurs in the energized heat generating sheet 1, the thermal efficiency is good and therefore the printing energy is small, so the load on the power supply is reduced and a low cost printing system can be constructed. Further, since the generated heat is discarded together with the energized heat generating sheet 1, there is almost no thermal history on the recording head side, and gradations with good reproducibility can be obtained.

Figure 3 shows the relationship between printing energy and printing density. 1
Since area modulation is applied to one dot, it is extremely advantageous in terms of cost and speed.

As for color printing, full-color printing became possible by selecting heat-melting inks of yellow, magenta, cyan, and, if necessary, black.

Next, FIG. 4, which shows the driving principle, is a conceptual diagram of a recording head according to the present invention, in which a plurality of recording electrodes 5 and a common electrode 6 are opposed to each other. At this time, the distance U between the common electrode 6 and the recording electrode 5 is set to a value close to the value of the pitch P between the recording electrodes. As shown in Figure 2 (a), this recording method uses the spread of current to apply area modulation, but this conversely causes the effects on each other when driving multiple recording electrodes. If the image is blurred, the gradation cannot be reproduced. Therefore, in the present invention, the above! By making P close to P, it was possible to simultaneously select multiple recording electrodes by suppressing crosstalk between recording electrodes while ensuring current distribution. This enabled high-speed gradation printing.

This will be explained below through examples.

FIG. 5 shows the experimental values of 70 strokes between the recording electrodes when p = 0.2wb and n = 03wk. The figure shows the current flowing to the resistance layer when recording electrode A is driven alone. There are recording chambers i! on both sides of the recording electrode A, each S′IIs apart. When iiB+o are simultaneously driven and the current flowing through recording electrode A is used as a function, the horizontal axis is S1EII)
, the vertical axis is machined/engineered. If we allow 05% current crosstalk representing ×100, that is, for example, 5% heat dispersion, then from the figure, S≧1.2, and P =
Since it is 0.21%, it is possible to simultaneously drive every six recording north poles.

In the present invention, 1/8 time division driving is performed in which every eight lines are driven simultaneously, and the allocated time for each line is 11 nsee, making it possible to perform high-speed printing at a line scanning speed of 8 fnsee/His.

If even higher speeds are required, this can be achieved by increasing the drive power.

〔Example〕

Based on the above principle, the recording head of the present invention will be described below.

As shown in FIG. 6, the recording head 20 includes a recording electrode pattern 24 formed on an insulating substrate 21 made of ceramic or the like by vapor deposition and photoetching (α), and a recording electrode material 25 applied thereon by selective plating. (C), completed board 2
2 to a conductive plate made of metal or the like (a).

With the precision of photoetching technology and mass production possible, high-density recording heads can be realized at low cost.

Insulating substrate materials require heat resistance, so ceramics whose main component is alumina, alumina-based porous ceramics, and 5in.
2, steatite whose main component is MnO, orsterite 7, Macol (trade name), etc. are suitable.

Further, in order to improve the wear resistance, materials that can be plated with nickel-phosphorus, nickel-tungsten-phosphorus, etc. and have high hardness are suitable for the recording electrode material.

This recording head prints by pressing the cross section against the platen 80 as shown in FIG. Therefore, mechanical abrasion and electrical abrasion occur. Therefore, in order to ensure electrical contact with the current-carrying sheet, it is preferable to select a recording electrode 5 having a harder hardness than the insulating substrate 21.

Therefore, in the present invention, 7-orsterite is used as the insulating substrate material.
Nickel-tungsten-phosphorus was used as the electrode material.

As described in the driving principle, it is desirable that the distance between the recording electrode 5 and the common electrode 6 be approximately the same as the pitch of the recording electrodes.
For the pitch recording electrode, the thickness of 7-orsterite, which is the substrate material, was set to 0.11 m5.

Furthermore, in the present invention, the wiring 31 for mounting the drive IC is formed using thin film technology at the same time as the electrodes are formed, and 40 drive holes 0152 are formed on the 7-orsterite substrate 21 as shown in FIG.
By implementing this, a compact recording head 20 was realized. The recording head is 2.20121X5! +11II, the length of the recording electrode portion 5 is 5 ms, and the remaining portion is the wiring portion 61 for mounting the drive member 052. Since the signal line to the drive wire 031 crosses over, two-layer wiring is performed using a tape carrier.With the above configuration, a recording head with an A4 width of 8 dots/wb was realized.

FIG. 9 shows a conceptual diagram of a full-color printer according to the present invention. Recording paper 8 wound around a drum 80 and sheet supply section 8
2, the energized heat-generating sheets 1 fed through the feed roller 85 are overlapped on the drum 80 and recorded by the recording head 20. The head is pressed against the roller 80 by a presser spring 88, maintaining appropriate pressing pressure, and the recording head 2
0. Maintain uniform contact between the energizing heat generating sheet 1 and the recording paper O. The energizing heat generating sheet 1 is in the form of a roll, and as shown in FIG. , cyan 97, and black 9B are applied every one page in this order. Therefore, writing is performed four times to obtain one full-color record. Naturally, it is also possible to write six times in the six colors of yellow, magenta, and cyan.

In addition, the sheet structure has a three-layer structure: a resistance layer, a support layer, and an ink layer, but if the resin binder in the resistance layer is strengthened to create a two-layer structure of a resistance layer and an ink layer, both thermal efficiency and resolution are expected to improve. can.

High-precision alignment is required when overlapping colors. In the present invention, the recording paper 8 is wound around the drum 80 and fixed, and the position detector 91 detects the absolute position. The position signal from the position detector 91 is sent to the control unit 90, which provides feedback to the drum 80 for constant speed rotation, and to the sheet feed roller 82, sheet winding roller 83, and recording head drive circuit 84 for positioning. A signal is sent. As described above, the present invention has achieved highly accurate positioning.

With the above printing device, a full color copy of 200*iX300sm could be made in 40 seconds.

〔effect〕

As described above, the recording head according to the present invention has a simple structure and is suitable for mass production in terms of manufacturing method, so that it can be extremely compact and inexpensive.

Also, since it uses hard materials, it has excellent wear resistance and is highly reliable.

The present invention provides a full-color line printer head using an electric thermal transfer method, and its application range is extremely wide, including full-color printers, full-color TV printers, full-color copiers, monochrome printers, and even serial terminal printers.

[Brief explanation of drawings]

Figure 1 shows the printing principle of energized heat transfer. Figure 2 (a)
) and (b) illustrate the principle of area modulation based on the printing principle according to the present invention. Figure 3 shows the relationship between input energy and recording density. FIG. 4 shows a conceptual diagram of a recording head according to the present invention. FIG. 5 shows an example of a recording head with experimental values of one cross between one pole of the recording cylinder. FIG. 9 shows the system configuration of a full-color printer according to the present invention. FIG. 10 shows an energized heat-generating sheet used in a full-color printer. 1... Current heating sheet 2... Resistance layer 3... Support layer 4... Heat-melting ink layer 5... Recording electrode 6...
・Common N pole 8...Recording paper 20...Recording head 21...Insulating substrate 22...
Baked board 31...Wiring 32...Driver 0 Above Applicant Suwa Seikosha Co., Ltd. Agent Patent Attorney Mogami Tsutomu δ2 Diagram 50! 4th 4 (g) Figure 6- Figure 8 10-

Claims (6)

[Claims] (1) A recording head having a plurality of recording electrodes and a common electrode is pressed against the resistive layer of a sheet having a resistive layer and a heat-melting ink layer, and a current is applied to melt the heat-melting ink and transfer it to recording paper. In the printing device, the recording head has a three-layer structure of a conductive layer, an insulating layer, and a recording electrode, and is made by bonding a substrate on which the recording electrode is formed on an insulating substrate to a metal plate. A recording head characterized in that is the common electrode. (2) Claim 1, wherein the thickness of the insulating substrate is close to the pitch of the plurality of recording electrodes.
Recording head as described in section. (3) The recording head according to claim 1, wherein the hardness of the recording electrode material is smaller than or close to the hardness of the flame retardant material. (3) The recording head 0 according to claim 1, wherein the hardness of the recording electrode material is smaller than or close to the hardness of the non-flammable material. (4) The recording head according to claim 1, wherein the insulating layer is made of a highly heat-resistant material. (5) 1 High heat resistant materials include ceramic, steatite,
5. The recording head according to claim 4, wherein the recording head is forsterite or macor. (6) The recording head according to claim 1, characterized in that wiring for a driving integrated circuit is formed as a thin film on the same substrate as the recording electrode at the same time, and the driving integrated circuit is mounted.