| 摘要 |
PURPOSE: To obtain a nib with a fine writing line width, and secure a sufficiently high quality nib which is capable of writing over a long distance by forming a curvature on the outer peripheral part of the tip of a nib base material and making the radius of the curvature thicker than the thickness of a highly rigid coating film. CONSTITUTION: A curvature 3 is formed between a tip face 2 and a lateral wall 4, on the tip of a pipe-shaped nib base material 1 for which a metal such as stainless steel is used. In addition, a highly rigid coating film material such as titanium carbode is used as the highly rigid coating material 5, and is formed by a physical evaporation method such as sputtering. Further, the highly rigid coating film 5 is composed of a plat part 6 formed on the tip face 2 and a curved face part 7 formed on the arc 3, and a detour part 8 formed on the lateral wall 4. The radius of the curvature 3 is established thicker than the thickness of the highly rigid coating film 5. That is, if the radius of the curvature 3 is smaller than the thickness of the coating film, cracks or chips generate on the highly rigid coating film 5 or peels off the base material 1, and the width of a writing line varies at the time of writing. |
