JPS63444Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a thermal printer head, and particularly to a printer head that can improve the adhesion of a platen roll.

A thermal recording system using a thermal printer head and a platen roll is often used as a recording system for facsimile machines, ticket vending machines, etc. In this method, as illustrated in Fig. 1, a glaze layer 2 is provided on a substrate 1 made of ceramics or metal oxide, and a large number of minute resistors 3 are arranged horizontally on the glaze layer 2, and both ends of each resistor are arranged horizontally. Wirings 4a and 4b are formed by vapor deposition or the like, and a wear-resistant layer 5 is provided thereon, and while a thermal paper 7 is run over a thermal printer head 6, resistors 3 are selectively connected in accordance with received image signals, etc. Electricity is applied to generate heat, and the platen roll 8 presses the thermal paper 7 against the abrasion-resistant layer 5 to display an image or signal on the thermal paper in color.

In this type of thermal recording method, it is necessary to press the thermal paper against the thermal printer head with uniform pressure in order to produce high-quality images and signals. Since warpage tends to occur in the direction perpendicular to the plane of the paper, the glaze layer, resistor group, and wear-resistant layer on the substrate often also warp. This warping occurs when the width of the board 1 is 200 to 240.
0.1 to 0.5 mm, but even with this degree of warping, if it becomes concave toward the platen roll 8, the pressing force will be insufficient near the center of the thermal paper 7. There is a drawback that the coloring in the vicinity becomes insufficient.

While examining the relationship between the properties of the substrate and the color image quality, the inventors of the present invention found that if the warp of the substrate was made to be convex toward the platen roll, the above-mentioned problems would not occur, and both the center and both ends would be It was also found that good quality images can be obtained. Moreover, this convexly warped board deforms in a direction that cancels out the warp due to the bimetal phenomenon when the temperature rises during printing, especially when an aluminum plate or the like is bonded to the back side as a heat sink material. It has also been found that this produces an effect of becoming close to a flat surface. Bimetal phenomenon is a phenomenon that occurs in bimetals made by bonding metals with different coefficients of thermal expansion, and is a phenomenon in which bimetals deform due to changes in temperature.For example, when the temperature rises, metals with higher coefficients of thermal expansion This indicates a state in which the metal has a good thermal expansion coefficient, so it curves toward a metal with a small thermal expansion coefficient. In this invention, an aluminum plate, etc., which has a larger coefficient of thermal expansion than a substrate made of ceramics, etc. is used as a heat sink, and by bonding it to the substrate, we utilize the bimetal phenomenon caused by the thermal expansion of the heat sink (larger than the substrate) when the temperature rises. do.

The present invention was made based on this knowledge, and aims to provide a thermal printer head in which a resistor, its wiring, and a wear-resistant layer are formed on the convex side of a warped substrate via a glaze layer. It is.

The details of the present invention will be explained below with reference to FIG.
In the figure, a warped substrate 1 made of a metal oxide such as alumina or ceramics has an aluminum heat sink material 9 adhered to its concave surface (lower side in FIG. 2), and an aluminum heat sink material 9 is bonded to the convex surface of the substrate. A glaze layer 2 and a large number of resistors 3 are formed, and although not shown, wiring and a wear-resistant layer are also formed.

The warpage of the board 1 is determined by B/A in Figure 2 being 0.04~
About 0.25%, preferably 0.1% is used,
A substrate having a warp greater than this is pretreated by polishing or the like so that the warp falls within the above range, and then the glaze layer 2 and the like are formed by a thick film method or a thin film method. 8 in the figure is a platen roll, which is usually made of silicone rubber with a shore hardness of about 50. 10 indicates an aluminum roller shaft.

As mentioned above, since the present invention forms a glaze layer and a resistor on the convex side of a warped substrate, the surface of the platen roll conforms well to the surface of the head, and appropriate pressing force is applied to both the center and both ends. , so high image quality can be obtained over the entire surface. In addition, especially when using a heat sink material, when it is heated during use, it deforms due to the bimetal phenomenon to counteract the warpage of the board and becomes close to a flat surface, and the resistor side has a convex surface in advance. Since a substrate having such a warp is used, it is also possible to prevent the resistor side from becoming a concave surface. In this way, according to the present invention, substrates that were conventionally used were either discarded as defective products due to warping, or were used after polishing until they became almost completely flat, but can be used as is or with some polishing. Since it can be used after processing, it can improve product yield and contribute to cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the use of the thermal printer head, and FIG. 2 is a longitudinal sectional view showing an example of the use of the thermal printer head of the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Glaze layer, 3... Resistor, 4a, 4b... Wiring, 5... Wear-resistant layer, 6...
...Thermal printer head, 7...Thermal paper, 8...
...Platen roll, 9...Heat sink, 10...
...roller shaft.

Claims (1)

[Claims for Utility Model Registration] (1) A resistor, wiring, and wear-resistant layer are formed on the convex side of a warped board via a glaze layer, and a heat sink is bonded to the concave side of the board. A thermal printer head configured to cause deformation to cancel the warping of the substrate due to a bimetal phenomenon when heated. (2) Warpage is 0.04 to 0.25% of the longitudinal length of the board.
A thermal printer head according to claim 1 of the utility model registration claim.