Patent ID: 6154231
Filing Date: 2000-11-28
Classification: B41J

Abstract:
An ink jet apparatus comprising:sucking means for sucking an ink from a cap, said sucking means including a sucking space formed by a cylinder and a piston adapted to said cylinder, a movement of the piston in the cylinder being characterized by a piston stroke, wherein an internal pressure variation in said sucking space varies corresponding to a mutual relation of said cylinder and said piston, said sucking means having a suction opening for transmitting the internal pressure variation in said sucking space to a cap for covering an ink discharge opening of a recording head; andcontrolling means for controlling said sucking means so that a length of a stroke of the piston in the cylinder during an idle suction, when the suction is performed in a state where the cap is opened to atmosphere, is smaller than a length of a stroke of the piston in the cylinder during a true suction, when the suction is performed in a state where the cap is closed to the atmosphere, and the idle suction starts from a start point in which said piston and said cylinder are disposed relative to each other such that said piston shuts said suction opening at a same time or immediately after a start of the idle suction and advances toward a lower dead point of said cylinder,wherein the internal pressure variation in said sucking space is transmitted to the cap during the piston stroke of idle suction, andwherein the internal pressure variation transmitted to the cap during the piston stroke of idle suction is less than the internal pressure variation in said sucking space transmitted to the cap in true suction.