DIRECT LIQUID-TYPE WRITING UTENSIL AND POROUS FILTER FOR INK TANK OF DIRECT LIQUID-TYPE WRITING UTENSIL

摘要

PPROBLEM TO BE SOLVED: To provide a direct liquid-type writing utensil which can inhibit ink leakage without the necessity to arrange an ink buffer. PSOLUTION: This direct liquid-type writing utensil includes an ink tank (3) shaped like a cylindrical body accommodating ink (2) and a pen point (4) to which the ink (2) is supplied from the ink tank (3). When the cylindrical body is divided into a part A and a part B by a plane (23) which is perpendicular with a center axis (21) of the cylindrical body and equally distant along the center axis (21) from both end surfaces of the cylindrical body, the part A and the part B have each a venting hole (5). In addition, a porous filter (7) which allows permeation of air but does not allow permeation of the ink (2), is arranged in the venting hole (5). PCOPYRIGHT: (C)2008,JPO&INPIT