Liquid application unit with application needle for applying liquid material on target, and liquid application apparatus including liquid application unit

A liquid application unit for applying a liquid material onto a surface of a target using an application needle, the liquid application unit comprising:

• a plurality of application needle units each including the application needle and a liquid material container in which the liquid material is stored and from which the liquid material is supplied to the application needle;
• a support that supports the plurality of application needle units and prevents movement of the plurality of application needles relative to the support;
• a push mechanism configured to move the application needle relative to the target and the liquid material container in a first direction;
• and
• a rotation mechanism configured to change a relative positional relation between the plurality of application needle units and the push mechanism,
• wherein the plurality of application needle units are integrally attachable to and detachable from the push mechanism and the rotation mechanism,
• wherein each of the plurality of application needle units further includes
• a first elastic electric member that is configured to bias the application needle in the first direction,
• a moving portion that has a wall having a first side and a second side that is connected to the application needle through the first elastic electric member, and moved by the push mechanism relative to the target,
• a base portion that is fixed to the push mechanism and has a first top wall,
• a rod externally inserted inside the base portion through the first top wall of the base portion, the rod having a first end to be coupled to the push mechanism and a second end that is in contact with the first side of the wall of the moving portion, and
• a second elastic member disposed between the first end of the rod and the first top wall of the base portion to bias the first end away from the first top wall,
• wherein the application needle is biased by the first elastic member toward the target relative to the moving portion,
• wherein the first elastic member is arranged between the second side of the wall of the moving portion and the application needle,
• wherein (1) the rod and the second elastic member, (2) the wall of the moving portion, (3) the first elastic member, and (4) the application needle are aligned in that order along the first direction, and
• wherein the push mechanism pushes the rod to move the moving portion, the first elastic member, and the application needle in the first direction in order to apply the liquid material to the surface of the target.