Adjustment mechanism and adjustment method

An adjustment mechanism for positionally adjusting and fixing a liquid discharge head to a component-fixable member, comprising:

• a first plate, being changeable in position in a horizontal direction relative to the component-fixable member, and the first plate is fixable to the component-fixable member;
• a second plate, being mountable on the first plate and movable in the horizontal direction relative to the first plate, and the second plate being structured to have the liquid discharge head be securely fitted therein;
• a first biasing unit, being attachable to one end part of the second plate, and the first biasing unit having a lift-off preventer operable to bias the second plate in the horizontal direction and to deter the second plate from lifting upward off the first plate;
• and
• a moving member, being attachable to another end part of the second plate, and the moving member being operable to move the second plate against a biasing force of the first biasing unit and to locate the another end part;
• wherein the first biasing unit comprises:
• a pressing member that presses the second plate;
• and
• an biasing force generator that biases the pressing member toward the second plate, wherein
• the pressing member is slidably attachable to the first plate along the horizontal direction through a slide groove formed in the first plate, the pressing member being prevented from falling off the first plate by the slide groove.