JPH02245342A - Printing and recording head - Google Patents

Abstract

PURPOSE:To attain the high reliability of the electric contact of an electrode part with an ink medium, to accomplish contact with less press-contact force and to reduce wear of an ink recording medium by positioning a projecting part, which is composed of a conductive material and is formed on a part of recording electrodes that is not coated with an insulating film, closer to a head top than the top of the recording electrodes. CONSTITUTION:A plurality of patterned recording electrodes 2 are disposed on a substrate 1, and are coated with an insulating film 3 except their tops. A projecting part 4 including parts 4a, 4b, 4c and 4d is formed on the exposed part of the recording electrodes 2 that is not coated with the insulating film 3. Each of the recording electrodes 2 is disposed a distance (d) away from the top of a printing and recording head, and the insulating film 3 lies between the tops of the recording electrodes 2 and the top of the printing and recording head. Since the top of the projecting part 4 is closer to the head top than the top of the recording electrode 2, the projecting part 4 alone comes into contact with a printing and recording medium and the contact part can be controlled in terms of space. In addition, contact pressure applied to the overall printing and recording head can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a print recording head used in an electrical transfer recording system.

Conventional technology Conventionally, an electric current recording method has been proposed as a print recording method in which an image is formed by converting an image electrical signal into thermal energy, melting the ink layer with the thermal energy, and transferring it to transfer paper. .

As shown in FIG. 3, the print recording head used in such a recording method is equipped with a return electrode 5 having a larger contact area than the recording electrode 2, so that the recording electrode and the return electrode are integrated. (for example, see Japanese Unexamined Patent Publication No. 171666/1989), or as shown in FIG. Print recording heads and the like have been proposed.

Problems to be Solved by the Invention In the former print recording head, since a recording electrode and a return electrode are present on the contact surface with the print recording medium, the pressure contact area of the print recording head becomes large, and it is necessary to increase the total pressure. Therefore, there are problems such as it is difficult to achieve uniform pressure contact, and the torque of the drive roll increases, resulting in a loss of reliability of print recording.

Furthermore, the latter type of print recording head requires the end face of the head to be in surface contact with the print recording medium when recording an image. Therefore, if the print recording head is tilted with respect to the print recording medium, the contact rate will be extremely poor, so it must always be held vertically, which poses the problem of requiring a highly accurate head holding mechanism. .

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

In other words, an object of the present invention is to have high reliability in electrical contact between an electrode part and an ink medium, to enable sufficient contact even with a small pressure contact force, to have little wear with the ink recording medium, and to be able to be used for a long period of time. The purpose of this invention is to provide a print recording head that is capable of printing.

Means for Solving the Problems The present inventors first developed a print recording head in which the above-mentioned conventional problems were improved by providing a conductive protrusion near the tip of the recording electrode provided on the substrate of the print recording head. However, as a result of a rough study, it was discovered that durability could be significantly improved by preventing the tip of the recording electrode from being exposed at the edge of the tip of the print recording head, and this led to the completion of the present invention. Ta.

That is, in the print recording head of the present invention, a plurality of recording electrodes are arranged in parallel on a substrate, and the plurality of recording electrodes are coated with an insulating film except for the tips, and the insulating film of the recording N pole is A print recording head is formed with a protrusion made of a conductive material on the tip that is not covered with a film, and the protrusion is
It is characterized by being located closer to the head tip than the tip of the recording electrode.

In the print recording head of the present invention, the substrate on which the recording electrodes are disposed preferably has an elastic layer.

In the print recording head of the present invention, the protrusion made of a conductive material is preferably provided so as to protrude from the insulating film by 1 to 200 μm, more preferably by 5 to 5 ONt, thereby further improving the contact stability. be done.

Further, the protrusion made of a conductive material may have any shape, for example 1. It is possible to use a shape having a square, rectangular, circular or oval shape. Further, it is preferable that the protrusion made of a conductive material is provided with a high melting point metal or conductive ceramic as a wear-resistant layer to prevent wear.

Function: The print recording head of the present invention is used to obtain a recorded image by an electric transfer recording method or an electrostatic recording method. For example, in the current transfer recording method, the print recording head is
It is brought into pressure contact with an ink recording medium having a heat generating layer and a heat-melting ink layer, so that the plurality of recording NFi of the print recording head slides on the ink recording medium. The image electrical signal from the print recording head is input to the heating element layer, generating Joule heat in the heating element layer, thermally melting the adjacent ink layer according to the image shape, and transferring the ink to the transfer material (generally paper). The layers are transferred and recording is performed.

In the present invention, as described above, since the tip of the protrusion is located closer to the head tip than the tip of the recording electrode, the print recording electrode is not exposed even if the print recording head is worn out due to sliding friction. Therefore, there is no occurrence of two-point contact between the protrusion and the recording electrode due to wear, and the current-carrying area does not increase, so the resistance value does not decrease.

Further, in the print recording head of the present invention, when the substrate is made of an elastic material, even if there are irregularities or undulations on the surface of the print recording medium, the print recording head deforms accordingly. Therefore, the protrusion provided at the tip of the recording electrode acts to maintain stable contact at all times.

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

FIG. 1 shows a print recording head according to an embodiment of the present invention, in which (a) is a cross-sectional view, (b) is a longitudinal cross-sectional view, and (C) is a perspective view. A plurality of recording electrodes 2 formed in a pattern are arranged in parallel on a substrate 1, and the recording electrodes are covered with an insulating film 3 except for their tips. Projections 4 (4a, 4b, 4c, 4d) are formed on the exposed portions of the recording electrode that are not covered by the insulating film. Each recording electrode is arranged such that its tip is located a distance d from the tip edge of the print recording head, and is therefore located between the tip of the recording electrode and the tip edge of the print recording head. An insulating film is present. In the present invention, the distance from the tip edge of the print recording head to the tip of the protrusion is preferably from 10 to 70 degrees,
The tip of the recording electrode only needs to be in contact with the protrusion.

As the substrate 1, a rigid substrate such as insulating ceramic, plastic, or metal coated with insulation is used. Also, as an elastic layer on the rigid substrate, silicone rubber, urethane rubber, synthetic rubber, natural rubber, porous material, It is possible to use a material in which layers of a foamable material or the like are laminated, and an insulating film made of polyimide, polyester, or other heat-resistant plastic is further laminated thereon.

A plurality of recording electrodes are formed in parallel in strips on the substrate, and are made of conductive metals (Ni, Cr, ALI, CIJ,
Ta, Ti, Fe, AI, W, Zn, Sn, Pt, Pb
and alloys containing them) by vacuum evaporation, sputtering, electroless plating, electrolytic plating, etc.
A film can be formed to a thickness of ~50 μm, and then the formed metal film can be patterned into a stripe shape by a combination of light or laser phosphorography and wet etching, or a combination of dry etching. .

The formed recording electrodes are then covered with an insulating film, in which case a portion of each recording electrode including its tip is exposed. for example,
A photosensitive insulating film (dry film) is bonded by thermocompression and removed by photolithography and wet etching to expose a portion of the recording electrode corresponding to the portion that contacts the print recording medium. Alternatively, the recording electrodes can be exposed by thermocompression bonding of an insulating film without using a photosensitive insulating film, by using a resist film, and by a combination of photophosphorography and dry etching. The thickness of the insulating film is preferably in the range of 5 to 50 mm. In addition, the shape and size of the portion of the recording electrode that is not covered with the insulating film, that is, the exposed portion, may be any shape and size as long as it does not come into contact with the adjacent recording electrode, but the shape may be rectangular or circular. is preferable, and the size difference is preferably about the width of the electrode.

A protrusion made of a conductive material is formed on the exposed portion formed on the recording electrode. For example, conductive metal (N i
, Cr, OL+, etc.) is deposited on the exposed portion of the recording electrode by electrolytic plating so as to be thicker than the insulating film to form a protrusion.

It is preferable that this protruding portion protrudes from the insulating film by 0.5 to 200 JJfr1, particularly 5 to 50 JJfr1. When the protrusion is lower than 0.5 mm, there is not much difference in effectiveness from a print recording head without a protrusion. 200 on the contrary
If the height is higher than that, the protrusion is likely to break, and it is difficult to manufacture the protrusion so that it does not come into contact with adjacent protrusions.

In the present invention, it is preferable to provide a wear-resistant layer of a high melting point metal, conductive ceramic, or the like on the surface of the protrusion.

In the above drawing, the protrusions of the recording electrodes are arranged in a line parallel to the contact surface, but they may be arranged in a staggered manner, or three or more protrusions may be arranged in a row parallel to the contact surface. It may also be in a saw-like shape with a parallel/v shape.

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

An example of a substrate in which an elastic layer and an insulating film are laminated on an aluminum plate is shown.

First, a polyimide film is used as an insulating film, CLJ is vacuum-deposited on it to a thickness of 1, and then a width of 5ON1 is formed by lithography and wet etching.
Recording electrodes were formed in stripes with one pitch of 125 JIIrI. A photosensitive film (dry frame) with a thickness of 10#i is placed on the insulating film on which the recording electrode is formed.
A 70 x 70 square exposed area was formed at the tip of the recording electrode by thermocompression and photolithography and wet etching.

Ni was made to protrude from the dry film by electrolytic plating on this exposed part to provide a protruding part.

A wiring board based on the formed insulating film, a silicone rubber plate (rubber hardness 50, thickness 1#) and an aluminum plate (thickness 3#) are bonded with an epoxy thermosetting adhesive, and the protrusions are bonded together. 5 points below the leading edge of the print recording head.
A print recording head was created by cutting with a dicing saw so as to be positioned at intervals of ON1.

The produced print recording head was tested as shown in FIG. That is, surface resistance 600Ω/mouth, thickness 20
tIM's conductive polyimide film 11 has a thickness of 2000 mm.
The film coated with the human aluminum film 12 is wound around an aluminum drum 9 with a diameter of 100tIIrI with the coated side facing inside, and the print recording head 8 is mounted using a weight 10 at a pressure of 500 g/cm and a contact angle θ=30. The resistance value between the recording electrode and the aluminum drum was measured while the aluminum drum was rotated, and how the change in resistance value changes with the cumulative number of rotations was investigated.

For comparison, the same test was conducted using the same print head as in the above example except that the recording electrodes extended to the leading edge of the print head as shown in FIG.

The results obtained are shown in Table 1 below. The values in the table indicate the percentage of electrodes whose resistance change rate was ±50% or more with respect to the initial resistance value.

As is clear from the above results, the print recording head of the present invention has superior durability compared to the comparative example.

Effects of the Invention In the print recording head of the present invention, since the tip of the protrusion formed on a part of the recording electrode is located closer to the head tip than the tip of the recording electrode, only the protrusion can be used as a print recording medium. It comes into contact and functions to control the area of contact.

Therefore, the contact pressure of the print recording head as a whole can be reduced. In addition, as mentioned above, the tip of the recording electrode and the edge of the print recording head are separated by an insulating film, so even if the print recording head is worn out due to sliding friction, the print recording electrode will remain intact. never exposed. Therefore, there is no possibility of two-point contact between the protrusion and the recording electrode due to wear, and since there is no increase in the energized area, the resistance value does not decrease, making it possible to perform good print recording over a long period of time. Become.

[Brief explanation of drawings]

FIG. 1 shows a print recording head of the present invention, in which (a) is a cross-sectional view, (b) is a longitudinal cross-sectional view, and (C) is a perspective view, and FIG. 2 is a print-recording head of a comparative example. This is a vertical cross-sectional view, and the third
4 and 4 are perspective views of a conventional print recording head, respectively, and FIG. 5 is an explanatory diagram for explaining a test method for the print recording head. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Recording electrode, 3... Insulating film, 4... Protrusion part, 5... Return electrode, 6... Plate-shaped rigid body, 7... Insulating film, 8...Print recording head,
9... Aluminum drum, 10... Weight, 11.
... Conductive polyimide film, 12... Aluminum film. Patent applicant Fuji Xerox Co., Ltd. Agent
Patent Attorney Tsuyoshi Watanabe Figure 2 Corpse Exhaustion Figure 3 Figure 5 Figure 4

Claims (4)

[Claims] (1) A plurality of recording electrodes are arranged in parallel on a substrate, and the plurality of recording electrodes are coated with an insulating film except for their tips,
A print recording head in which a protrusion made of a conductive material is formed at the tip of a recording electrode that is not covered with an insulating film, the tip of the protrusion being closer to the head than the tip of the recording electrode. A print recording head characterized by being located on the tip side. (2) The print recording head according to claim (1), wherein the protruding portion is provided to protrude from the insulating film by 1 to 200 μm. (3) The print recording head according to claim (1), wherein the protrusion is coated with a wear-resistant layer made of a high-melting point metal or a conductive ceramic. (4) The print recording head according to claim (1), wherein the substrate has an elastic layer.