| 摘要 |
PURPOSE:To obtain the same quality of printing with that of ordinary-paper printing, by specifying the width and the radius of curvature of a partial glaze layer of a thermal head corresponding to printing of paper of low smoothness so that a contact surface pressure to deform elastically the ridged portion of the surface of the paper of low smoothness be given by a pressing force of the head for the ordinary-paper printing. CONSTITUTION:The highest contact surface pressure is obtained when the contact width of a partial glaze layer 3 in the case when it is pressed on the surface of paper of low smoothness is larger slightly than the width (d) of a heating resistor 4, on the condition that a pressing force of a head is identical. Therefore, the width (w) of the glaze layer 13 is set to be 1-4 times larger approximately than the projected width (d) of the heating resistor 4 or to be 450mum or less approximately in consideration of the easiness for manufacture as well. In addition, the height (h) of the glaze layer 3 is set generally to be 30-50mum. Accordingly, a radius of curvature obtained when the cross section of the glaze layer 3 is formed in the shape of a circular-arc is 1,200mum or less when it is calculated by the Hertz's theoretical formula of contact. The same effect can be obtained also when a partial glaze layer having a large radius of curvature is formed to be triangular substantially by etching. |
