JP2687514B2 - Print recording head - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print recording head for applying an image electric signal to a print recording medium.

2. Description of the Related Art Hitherto, an energization recording method has been proposed as a print recording method for forming an image by converting an image electric signal into thermal energy, dissolving an ink layer with the thermal energy, and transferring the image to transfer paper. .

As a print recording head used in such a recording system, a return electrode having a larger contact area than the pattern electrode is provided integrally, and a print recording head formed by integrating the pattern electrode and the return electrode (for example, Kaisho 59
No. 171666), or a print recording head or the like formed by laminating a patterned electrode made of a patterned metal layer and a ceramic material on a ceramic substrate.
These print recording heads have various problems. For example, in the former case, since the pattern electrode and the return electrode are present on the contact surface, the pressure contact area of the print recording head becomes large, and the total pressure contact becomes large. There is a problem that it is necessary to take a large pressure, it is difficult to perform uniform pressure contact, and the torque of the drive roll becomes large. In the latter case, the print recording head must always be held vertically. However, there is a problem that a highly accurate head holding mechanism is required.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In order to solve the above conventional problems, the present inventors have
Previously, a proposal was made in which a conductive protrusion was provided near the end face of the print recording head, but in these print recording heads, the conductive protrusion provided near the tip of the pattern electrode was
The length in the main scanning direction (electrode width direction) and the length in the sub-scanning direction (electrode length direction) are formed to be substantially the same.

However, when the ratio of the length in the main scanning direction to the length in the sub scanning direction of the conductive protrusions is substantially the same, there are the following problems. 1) When analog recording is carried on an ink recording medium and printing is performed by controlling the pulse width of a signal, even if the size of one dot is small, it becomes the same as the size of the conductive protruding portion, resulting in high resolution. There is a problem that can not be obtained.
2) When the ink recording medium is stepwise conveyed and the pulse width of the signal current is controlled or the electric energy is controlled to perform the printing recording, since the dot size is controlled by the input energy amount, the conductive protrusion is generated. In order to hit a dot larger than the size of a part, since a large amount of energy is applied to the heating element layer of the ink recording medium per unit volume, the addition to the heating element layer becomes large, and when using the recycling method, the ink There is a problem that the life of the recording medium is shortened. 3) When the ink recording medium is analog-conveyed and the electric energy of the signal current is controlled to perform the print recording, the same problem as in the above 2) occurs.

The present invention has been made in view of the above circumstances.

That is, an object of the present invention is to provide a print recording head capable of arbitrarily performing dot modulation in the sub-scanning direction with high resolution. Another object of the present invention is to provide a print recording head that does not require a large amount of energy to be applied to an ink recording medium.

Means for Solving the Problems The print recording head of the present invention includes an insulating substrate, a plurality of pattern electrodes arranged in parallel on the insulating substrate, and an exposed portion near the tip of the pattern electrode. An insulating layer and a conductive protrusion provided on the exposed portion, wherein the ratio of the length of the conductive protrusion in the main scanning direction to the length in the sub-scanning direction is 4 or more. To do.

In the print recording head of the present invention, a cutout groove may be provided between the pattern electrodes at least at the leading end of the plurality of pattern electrodes.

Action The print recording head of the present invention is used when a recorded image is obtained by a current transfer recording method or an electrostatic recording method. For example, in the electric transfer recording method, the print recording head is pressed against a print recording medium having a heating element layer and a heat-meltable ink layer so that the plurality of pattern electrodes of the print recording head slide on the print recording medium. Contact. An image electrical signal from the print recording head is input to the heating element layer, Joule heat is generated in the heating element layer, the adjacent ink layers are melted by heat according to the image shape, and the ink is transferred to the transfer material (generally God). The layers are transferred and the recording is done.

In this case, in the print recording head of the present invention, the shape of the conductive protrusions formed on the pattern electrodes has a ratio of the length of the conductive protrusions in the scanning direction to the length in the sub-scanning direction of 4 or more. Therefore, the area of the electrode is smaller than that in the case of having a square shape, and the dots at the start of ejection are also elongated and the area is small. Then, if the applied pulse width is lengthened,
Correspondingly, the dot also becomes longer, so dot modulation becomes possible by adjusting the pulse width. Therefore, when the print recording head of the present invention is used to carry out analog recording of the ink recording head to perform print recording, dot modulation in the sub-scanning direction can be arbitrarily performed by controlling the applied pulse width.

Examples Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings.

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a vertical sectional view thereof. A plurality of pattern electrodes 2 formed in a pattern are arranged in parallel on the insulating substrate. These pattern electrodes are formed by the insulating layer 3 except for a partial region near the tip thereof. Is covered. These exposed parts that are not covered by the insulating film of the pattern electrodes,
The conductive protrusion 1 is formed. The insulating substrate is the second
In the figure, it is composed of an insulating support layer 4, an elastic layer 5 and a rigid body 6.

In the present invention, as the insulating substrate, a substrate made of an insulating material, a rigid metal body laminated with an insulating material, or the like is used. As the insulating material, polyester, vinyl chloride resin, polyurethane, polyorganosilicone, polyacetal, polyimide resin, polyimideamide resin,
Insulating resins such as polyacrylate, polyurea, and epoxy resin can be used, and elastomer can also be used. When the insulating substrate is made of insulating resin, the thickness is preferably in the range of 0.1 mm to 7 mm. If the thickness is less than 0.1 mm, sufficient elastic pressure contact cannot be obtained. On the other hand, if it is thicker than 7 mm, it exhibits a rigid body behavior, and sufficient stable contact characteristics cannot be obtained. When aluminum or another metal rigid body is used, it is necessary that an insulating layer is formed on the surface thereof, but it is preferable to provide an insulating elastic layer.

A plurality of pattern electrodes are formed in parallel on the insulating substrate in a strip shape. Examples of usable substances include, for example, conductive metals (Ni, Cr, Au, Cu, Ta, Ti, Fe, Al, Mo, W, Z
n, Sn, Pt, Pb and alloys containing them, conductive metal compounds (VO ₂ , RuO ₂ , TaN, Ta ₂ N, HfB ₂ , TaB ₂ , MoB ₂ , B)
_{4 C, MoB, ZrC, VC} , TiC , etc.), and mixtures containing the same and the like substances. The volume resistivity value required for these substances may be 10 ⁻⁴ Ω · cm or less. Pattern electrodes made of these materials are used for metal foil adhesion, electrolytic plating,
Electroless plating, vacuum deposition method, sputtering method, printing and other coating methods, PVD method, CVD method, plasma film deposition method, etc. can be selected according to the material and substrate material, 0.1 μm
The film may be deposited to a thickness of up to 50 μm. In order to form a striped pattern electrode, the deposited conductive layer is
It can be formed by patterning by a combination of light and laser or electron beam lithography and wet etching, or a combination of dry etching. Alternatively, a pattern electrode can be formed by directly drawing a conductive layer.

The formed patterned electrode is then covered with an insulating layer. For example, a photosensitive insulating film (dry film) is thermocompression-bonded, and is removed by photolithography and wet etching in order to expose a pattern electrode in a portion corresponding to a portion in contact with a print recording medium. Alternatively, the pattern electrode can be exposed by thermocompression bonding the insulating film without using the photosensitive insulating film, using a resist film, and using a combination of photolithography and dry etching. The thickness of the insulating layer is 5-50μ
A range of m is preferably used.

A portion not covered by the insulating layer on the pattern electrode,
That is, a conductive protrusion is formed on the exposed portion. The conductive protrusion is formed, for example, by coating a conductive metal (Ni, Cr, Cu, etc.) on the exposed portion on the pattern electrode by electrolytic plating. It can be formed by being attached so as to be thicker.

In the present invention, the conductive protrusion has a rectangular shape with long sides in the electrode width direction, as shown in FIG. The ratio of the length of the conductive protrusion in the main scanning direction to the length in the sub scanning direction needs to be 4 or more, and preferably 8 or more.

The conductive protrusion is 2.0 μm to 100 μm thicker than the insulating layer,
In particular, it is preferable that the protrusion is provided by 10 μm to 40 μm.

In the print recording head of the present invention, a cutout groove may be provided between the pattern electrodes at least at the leading end of the plurality of pattern electrodes. The notch groove can be formed by a rotary cutting method using a cutting disk, a laser processing method, a dry etching method, a fluid cutting method, or the like. The depth of this notch groove is 5 mm to 40 m from the tip of the print recording head.
Good range for m.

Next, a more specific example of the print recording head of the present invention will be described.

Example of preparation As an insulating film for arranging electrodes, thickness 30μ
m polyimide film was used, and a copper foil having a thickness of 20 μm was laminated thereon as an electrode material and attached with a thermosetting adhesive. The bonded copper foil is patterned by photolithography and etching, electrode width 80μm, pitch 125μ
m of striped pattern electrodes arranged in parallel were formed. Next, a thermosetting polyimide resin solution was applied to the formed pattern electrode side and heat-cured to form an insulating layer having a thickness of 10 μm. The thermosetting polyimide resin on the pattern electrodes is removed by photolithography and etching, and each pattern electrode is 80 μm x 20 μm on each spot.
Drilled a square hole of size.

Ni in the above holes by electroplating, 15 μm thicker than the insulating layer
The protrusion was formed up to the protruding height, and a protrusion made of Ni was formed.

In order to use the protrusions arranged on the pattern electrodes as the contact electrodes of the print recording head, the wiring board was cut at a position 16 μm from the row of the protrusions.

Next, with the protruding surface of the wiring board facing up, this wiring board, a 1 mm thick silicone rubber plate and a 3 mm thick aluminum plate were laminated in this order and bonded with a thermosetting adhesive. . In this case, the end faces of the respective materials were adhered so that the row of the protruding portions of the wiring board was located at the edge of the print recording head.

Comparative Example A print recording head was prepared in the same manner as in the preparation example. However, the pattern electrode has an electrode width of 80 μm and a pitch of 125 μm, and the size of the holes in the insulating layer on the pattern electrode is 65 μm × 65.
μm. (Refer to FIG. 3) Evaluation method 1 Using the print recording apparatus shown in FIG.

In the figure, 7 is a print recording head, 8 is an ink recording medium, 9 is a transfer paper, and 10 is a platen roll.

An aluminum drum having a diameter of 50 mm was used as a platen roll, and an ink recording medium was laminated from the platen roll side so that the transfer paper and the ink surface side faced up, and pressure contact was performed with a print recording head. The platen roll rotates at a constant speed of 5 rpm by an analog motor to convey the transfer paper and the ink recording medium,
A rectangular pulse electric signal is applied from the print recording head,
Dot transfer was performed. The electric signal was applied at a constant voltage while changing the pulse width condition.

The obtained transferred image has the result shown in FIG. In FIG. 5, (a) shows transfer dots when the print recording head of the present invention is used, and (b) shows transfer dots when the print recording head of the comparative example is used.
In both (a) and (b), when the pulse width is 1 ms, dots having the size of the conductive protrusion are obtained. Pulse width is 5ms, 2
When it becomes as large as 0 ms, the dot also becomes longer, but the length in the electrode width direction is longer in (b) than in (a).

In the case of a long dot close to a line, the difference between (a) and (b) is small, but a dot smaller than the size of the conductive protrusion cannot be printed. When modulation is performed, the print recording head of the comparative example cannot output a high resolution image.

Advantageous Effects of Invention In the print recording head of the present invention, the shape of the conductive protrusions formed on the pattern electrodes is such that the ratio of the length of the conductive protrusions in the main scanning direction to the length in the sub-scanning direction is 4 or more. Therefore, when the print recording head of the present invention is used to carry out analog recording of the ink recording head, the dot recording in the sub-scanning direction can be arbitrarily performed by controlling the applied pulse width. Print recording can be performed with high resolution. Furthermore, since it is not necessary to apply a large amount of energy to the ink recording medium, it is possible to prevent the heating element layer of the ink recording medium from being largely added, and it is possible to extend the life of the ink recording medium.

In addition, when the notch groove is provided at the position between the pattern electrodes, the pattern electrodes are brought into pressure contact with each other one by one or independently for each of a plurality of groups, so that the pattern electrodes are not covered with dust or the like. Even if foreign matter is mixed in, the entire print recording head does not float up, and even if a part of the printout head floats, the floating is less likely to affect other pattern electrodes. If it exists, it can be blown off into the notch groove, so that it is possible to remove foreign matter, and since the contact reliability of each pattern electrode is improved, the pressure contact pressure can be reduced, and the ink recording medium Contributes to the friction characteristics of, the high reliability of the pattern electrode contact portion, and the long life.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the print recording head of the present invention, FIG. 2 is a sectional view taken along the line AA of the print recording head of FIG. 1, and FIG. 3 is a print recording head of a comparative example. Top view of the fourth
FIG. 5 is an explanatory view for explaining a schematic configuration when print recording is performed using the print recording head of the present invention, and FIGS. 5A and 5B show print recording heads of the present invention and comparative example, respectively. It is explanatory drawing explaining the shape of the transfer dot when used. 1 ... Conductive protrusion, 2 ... Pattern electrode, 3 ... Insulating layer, 4 ... Insulating support layer body, 5 ... Elastic layer, 6 ...
Rigid body, 7 ... print recording head, 8 ... ink recording medium,
9: Transfer paper, 10: Platen roll.

Claims (2)

(57) [Claims] 1. An insulating substrate, a plurality of pattern electrodes arranged in parallel on the insulating substrate, an insulating layer having an exposed portion near the tip of the pattern electrode, and an exposed layer provided on the exposed portion. A print recording head, wherein the print recording head has a ratio of the length in the main scanning direction of the conductive protrusion to the length in the sub scanning direction of 4 or more. 2. The print recording head according to claim 1, wherein a cutout groove is provided between the pattern electrodes at least at a tip portion of the plurality of pattern electrodes.