JP3002583B2 - Edge type thermal head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end face type thermal head suitably used for a thermal type or thermal transfer type printer, facsimile or the like.

[0002]

2. Description of the Related Art Conventionally, as a thermal head used for a printer, a facsimile or the like, a flat thermal head in which a portion provided with a driver IC for driving and a heating resistor portion are provided on the same main plane of a substrate, JP-A-60-80
No. 81, Japanese Unexamined Patent Publication No. 61-40168, etc., an end-face type thermal head having a heating resistor provided on an end face of a substrate has been put to practical use.

[0003] In particular, the end face type thermal head has better contact property of the heat generating resistor portion with the thermal paper or film as compared with the flat type thermal head, and escapes to avoid contact between the drive circuit and the platen. It has been recognized that there is no need to provide, and it is more advantageous as it has various advantages such as easy miniaturization of the entire device and easy securing of the flatness of the portion where the heating resistor is provided. .

However, in such an end face type thermal head, in order to improve the recording quality of printing or printing, the distance between the recording electrode for electrically connecting the heating resistor and the return electrode is made uniform. When the substrate located between the electrodes is made of a thin plate that can meet such demands, it is extremely difficult to handle such a thin plate during head manufacturing. It is difficult and the mechanical strength cannot be sufficiently ensured. Furthermore, in such a conventional end face type thermal head, the above-mentioned contact property which is a feature of the end face type head is not sufficiently satisfactory.
Further, the heat generation response was not satisfactory.

[0005]

The present invention has been completed in view of the above-mentioned circumstances, and the problem to be solved is to improve the contact with a film or the like and to improve the heat generation responsiveness. It is an object of the present invention to provide an end face type thermal head which is excellent in recording quality and recording quality.

[0006]

According to the present invention, in order to solve the above-mentioned problem, at least the tip of the ceramic substrate is made thin, and at least the tip of the tip is provided with a heat-generating resistance film, A recording electrode and a return electrode for supplying an electric current to the resistive film are provided so as to be located only on the opposite main planes of the ceramic substrate. An end face type thermal head characterized in that a resistive film is provided at least at one end of the ceramic substrate while electrically connecting the resistive film, and at least one of the opposing main planes is provided with a reinforcing material. , Its gist.

[0007] In the present invention, the reinforcing member is preferably made of an easily wearable material.

In the present invention, it is preferable that at least the tip of the ceramic substrate has a substrate thickness of generally 10 to 90 μm, and the return electrode is provided on one of the opposed main planes of the ceramic substrate. It is preferable that it is constituted by a common electrode composed of joined electrode plates. Here, the main plane of the ceramic substrate in the end face type thermal head of the present invention refers to the substrate surface of the ceramic substrate following the substrate end surface that supports the heating resistor portion pressed against a film or thermal paper, in other words Indicates a substrate surface that does not come into contact with a film or thermal paper.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, some embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 3 each show an example of an end face type thermal head according to the present invention. In these figures, a ceramic substrate 2 is provided with a large number of stripe-shaped recording electrodes 4 on one main plane, and a return electrode corresponding to the shape of the substrate 2 on the other main plane. 6 are provided. On the end surface of the substrate 2, heat is generated at a predetermined thickness at least in the thickness direction (left-right direction in the figure) of the substrate 2 so as to be electrically connected to the recording electrode 4 and the return electrode 6. The resistance film 8 is provided directly. Also, in FIG. 1, at least at the tip of the head, outside the surface of the substrate 2 supporting the return electrode 6, and further in FIGS. 2 and 3, outside the surface of the substrate 2 (2 a) supporting the recording electrode 4. Reinforcing members 12 each having a predetermined thickness are adhered to each other with an adhesive 10 so as to be located, so as to form an integral structure.

In such an end face type thermal head, the ceramic substrate 2 needs to be formed at least at the head end portion as shown in the figure, and the entire shape is formed as a thin wall. In this case (FIG. 1), a notched portion is formed at the tip end by machining, press molding, or the like, so that a predetermined length of the tip end of the head where the heat-generating resistance film is provided becomes thin. (FIG. 2). Further, the thin plate or green sheet (2a) and the thick plate or green sheet (2b) are combined so that a predetermined length portion of the head end portion becomes thin. Even if they are integrally formed by laminating or joining and performing heat treatment or the like as necessary (FIG. 3), any of them can be adopted. In FIG. 2, the surface from the thick portion to the thin portion (cut portion) at the front end of the substrate 2 is an obtuse slope here, but even if it is an acute slope, Further, it may be a right-angled surface giving a stepped shape, or even a rounded surface (curved surface).

The thickness of the thin portion at the tip of the ceramic substrate 2 is appropriately selected according to the printing or printing characteristics required at the tip of the head. In the present invention, generally, about 10 to 90 μm, preferably about 20 to 70 μm is suitably adopted. That is, if the thickness is smaller than 10 μm, the width of the heat-generating resistive film becomes short and a good-quality dot shape cannot be obtained. If the thickness is more than 90 μm, the width of the heat-generating resistive film becomes long and the high-density From the point where the dot density cannot be obtained, it is desirable to set the thickness within the above range in order to obtain high-quality recording.

The ceramic substrate 2 is preferably a glass ceramic substrate, a free-cutting glass ceramic substrate, a zirconia substrate, a glass substrate, or the like, and more preferably a free cutting containing mica. A conductive glass ceramic substrate is used.

On both main planes of the substrate 2, a recording electrode 4 and a return electrode 6 for supplying a current to a heating resistance film 8 which is brought into contact with a film-shaped recording medium or thermal paper are provided respectively. Accordingly, the distance between the electrodes 4 and 6 is determined by the thickness of the front end of the substrate 2. However, since the front end is thin as described above, the heat-generating resistance film is formed. 8, when used for various recording methods, the heat-generating resistive film 8 is efficiently pressed against the film or the thermal paper, so that the contact property is remarkably improved, and the heat generated is efficiently transferred to a necessary portion. Good concentration can be achieved, and good heat response can be obtained, and further, recording quality can be improved.

As described above, the recording electrode 4 and the return electrode 6 provided on the opposing main planes of the substrate 2 are generally made of a normal conductor material. In particular, chromium, titanium, molybdenum, tungsten, nickel,
Metals such as gold and copper and alloys containing them, nitrides, carbides, borides and the like of these metals are appropriately selected and used. Further, the recording electrode 4 and the return electrode 6 are formed on the respective main planes of the substrate 2 by the usual thin film method or thick film method using the above-mentioned electrode material. The electrode 4 is usually patterned in accordance with the recording density of the head, while the return electrode 6 may be patterned in the same manner as the recording electrode 4, but is preferably provided as a common electrode. It is formed into a layer by a known appropriate technique, or is joined as a plate-like electrode. The thickness of the recording electrode 4 and the return electrode 6 is selected to be at least 0.5 μm or more, preferably 1 μm or more, and more preferably 3 μm or more. It can also be provided.

On the other hand, the heating resistance film 8 provided on at least the front end surface of the front end portion of the substrate 2 is preferably a thin film resistance film, a thick film resistance film, or the like having high heat pulse characteristics and high resistance. Generally, a material mainly composed of a high melting point metal or its alloy, a material mainly composed of a mixture of a high melting point metal or its alloy and any of oxides, nitrides, borides and carbides, or titanium, tantalum, chromium , Zirconium, hafnium, vanadium, lanthanum, molybdenum,
A material mainly composed of nitride, carbide, boride, silicide or the like of at least one element selected from tungsten and the like,
A material containing a ruthenium-based oxide as a main component or the like is appropriately adopted. And such a heating resistance film 8
Is formed on at least the front end surface of the substrate 2 by a normal thin film method or the like according to the recording density of the head, or provided in a continuous single band shape.

The heating resistance film 8 needs to be provided on at least the front end face of the front end of the substrate 2.
After the return electrodes 6 are formed, they are provided so as to cover the tips of the electrodes 4 and 6 so as to be electrically connected to the electrodes 4 and 6 as shown in the drawing. Alternatively, before forming the electrodes 4 and 6, the substrate 2
The heating resistance film 8 is provided in advance on the front end surface of the substrate 2, and then the electrodes 4 and 6 are formed on both main planes of the substrate 2, respectively. Things.

Further, in the thermal head having such a structure, at least one of the main planes of the substrate 2 is provided since at least the head end on which the heating resistance film 8 is provided is made thin. In order to reinforce at least the thin-walled portion at the head end, a predetermined reinforcing material 12 is adhered via the adhesive 10 so as to conform to the shape of the substrate at the head end. The reinforcing member 12 is preferably provided with a material having a lower hardness than the recording electrode 4 and the return electrode 6 and a higher wear resistance than the heating resistance film 8, or a protective layer (24) described later. in this case, although the that it easily abradable material is used than, in particular Knoop hardness of 1000 kgf / mm ² or less, more preferably 500 kgf / mm ² or less of metal, ceramic, glass, glass ceramics, etc. Materials are appropriately selected and used. As a result, the heating resistance film 8 provided on the end face of the substrate 2 has a shape slightly projecting forward from the end face of the reinforcing member 12 while sliding with the film, and can satisfy both mechanical strength and contact properties. It is.

More specifically, as the easily wearable material constituting the reinforcing member 12, free-cutting glass ceramic, free-cutting glass ceramic containing mica, free-cutting alumina, free-cutting boron nitride, A material mainly composed of a material selected from aluminum nitride, thin film, copper, aluminum, bronze, and the like, or a material obtained by combining them is preferably used. Among them, a free-cutting glass ceramic containing mica, Machinable alumina, free-cutting boron nitride, free-cutting aluminum nitride and other materials mainly
It is preferable because the head has excellent slidability and contact properties.

As described above, in such a thermal head structure, since the predetermined reinforcing material 12 is provided at least at the end of the head, when the thermal head is used, the thermal paper or film or the like is used. The exfoliation or the like of the heating resistance film 8 or the protective layer (24) due to the sliding contact is not caused, and the exfoliated material or the like is caught between the electrode and the thermal paper or the like, and obstructs printing or printing. It exhibits excellent characteristics in that it does not cause any problems.

The adhesive 10 for attaching the reinforcing material 12 to the substrate 2 as described above may be an inorganic material containing alumina, silica, boron nitride, or the like, or an epoxy, phenol, polyimide or the like. A resin-based material or a composite material containing such an inorganic material and a resin-based material may be used, and among them, an inorganic material containing alumina, silica, boron nitride, or the like is suitably selected.

In the present invention, if necessary, a suitable insulating material such as silicon oxide, silicon nitride, silicon carbide, Using a material appropriately selected from tantalum oxide, glass and the like, at least a protective layer 24
(See FIGS. 8 to 10), and the protective layer 24 can effectively prevent oxidation, abrasion resistance, insulation coating, and the like. The protective layer 24
Is provided according to a known method such as sputtering, CVD, and a thick film method, and is not limited to a single-layer structure selected from the above materials, and may be a multilayer structure including the above materials. When used for insulation coating of such leads, organic materials such as epoxy, phenol, and polyimide are advantageously used.

In the thermal head according to the present invention, as shown in FIG. 4, if necessary, an electrical insulating layer such as glass, a so-called glaze layer Is provided, and the recording electrode 4 and the return electrode 6 are supported thereon. As a result, the heat diffusion in the heating resistance film 8 is slowed down, and the resistance film 8 can be more firmly bonded to the substrate 2.

Further, various other embodiments according to the present invention are shown in FIGS. 5 to 10, respectively, wherein FIG. 5 first shows that electrodes 4, 6 are provided on both main planes, respectively. The heating resistor film 8 is attached to the tip of the
Is formed, the reinforcing material 12 is bonded to both main planes via the adhesive material 10, and FIG.
The recording electrode 4 is provided on one main plane of the substrate via the glaze layer 14 as in the previous example, while the return electrode 6 is
On the other main plane of the substrate 2, it is provided so as to be located only at the head end portion via the glaze layer 14, and reinforcing materials 12, 12 are provided on the recording electrode 4 and the return electrode 6 respectively with the adhesive 10. In this example, a head having such a structure is provided, and the lead 16 and the return electrode 6 are connected to the mounting substrate 18. As described above, the components are mounted by being joined via the adhesive 10.

FIG. 7 shows that after the heating resistor film 8 is provided at the tip of the substrate 2,
In this example, a recording electrode 4 and a return electrode 6 are formed. In addition, on the recording electrode 4 and the return electrode 6, reinforcing members 12, 12 similar to the case of FIG. 6 are joined and provided integrally.

FIGS. 8 to 10 show examples in which a suitable protective layer 24 is further provided on the heating resistance film 8. That is, FIG. 8 shows that the electrodes 4 and 6 are provided on both main planes of the substrate 2 via the glaze layer 14, respectively, and further outside the reinforcing material 1 via the adhesive 10.
2 and 12 are provided, and after the heating resistance film 8 is formed on the head end surface, a protective layer 24 having a predetermined thickness is provided so as to cover the head end surface. On the other hand, after the electrodes 4 and 6 are formed, the heating resistance film 8 and the protective layer 24 are sequentially formed, and thereafter, the reinforcing material 12 is provided. 4,6
In this example, the heating resistance film 8 and the protective layer 24 are sequentially formed only on the front end face of the substrate 2, and the reinforcing members 12, 12 are further provided outside the two main planes of the substrate 2.

The specific configuration and embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to the above description, and the gist of the present invention is not limited. It should be understood that various changes, modifications, improvements, and the like can be made to the present invention based on the knowledge of those skilled in the art without departing from the present invention.

[0028]

As is apparent from the above description, in the end face type thermal head according to the present invention, at least the front end portion of the ceramic substrate is made thin, and a heating resistance film is provided on at least the front end surface of the front end portion. In addition, since the recording electrode and the return electrode for conducting electricity to the heating resistor film are provided only on the main plane facing the substrate, the contact of the heating resistor portion with the thermal paper or film is good. It is excellent in heat generation response, so that the quality of printing or printing can be advantageously improved. In addition, a predetermined reinforcing material is provided at the tip (thin portion) of such a ceramic substrate. However, the thin portion is effectively reinforced, and the mechanical strength of the head can be advantageously secured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an end face type thermal head according to the present invention.

FIG. 2 is an explanatory sectional view showing another example of the end face type thermal head according to the present invention.

FIG. 3 shows an end face type thermal head according to the present invention.
It is sectional explanatory drawing which shows an example in which the board | substrate was made into the laminated structure.

FIG. 4 shows an end face type thermal head according to the present invention.
FIG. 4 is an explanatory cross-sectional view showing an example in which reinforcing materials are provided on both sides of a main plane of a substrate.

FIG. 5 is an end face type thermal head according to the present invention;
FIG. 10 is a cross-sectional explanatory view showing another example in which reinforcing materials are provided on both sides of a main plane of a substrate.

FIG. 6 is an explanatory sectional view showing another example of the end face type thermal head according to the present invention.

FIG. 7 is an explanatory sectional view showing another example of the end face type thermal head according to the present invention.

FIG. 8 is an explanatory sectional view showing another example of the end face type thermal head according to the present invention.

FIG. 9 is an explanatory sectional view showing another example of the end face type thermal head according to the present invention.

FIG. 10 is an explanatory sectional view showing another example of the end face type thermal head according to the present invention.

[Explanation of symbols]

 2 substrate 4 recording electrode 6 return electrode 8 heating resistance film 10 adhesive 12 reinforcing material 14 glaze layer 16 lead 24 protective layer

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/335 H01L 49/00

Claims (4)

(57) [Claims] At least the tip of the ceramic substrate is made thin, and a heating resistor film is provided on at least the tip face of the tip, and the recording electrode and the return electrode for supplying current to the heating resistor film are respectively provided with the recording electrode and the return electrode. The heating resistor film is provided so as to be located only on the opposite main plane of the ceramic substrate, and the recording electrode and the return electrode are electrically connected to the ceramic substrate front end surface side portion. An end face type thermal head, wherein a reinforcing material is provided on one or both of the main planes facing each other. 2. An end face type thermal head according to claim 1, wherein said reinforcing member is made of an easily wearable material. 3. The end face type thermal head according to claim 1, wherein at least a tip portion of the ceramic substrate has a substrate thickness of 10 to 90 μm. 4. The end face type thermal device according to claim 1, wherein the return electrode is constituted by a common electrode formed of an electrode plate joined to one of the opposing main planes of the ceramic substrate. head.