A radiation-sensitive resin composition includes an acid generating agent to generate a compound represented by a following formula by irradiation with a radioactive ray. The microlens has a concave bottom face and a convex top face. The average AC output power may be a predetermined value or a calculated value based on sensed or measured signals. The suspension also has a reinforcing plate to hold and fix a second side of the resilient part between the reinforcing plate and the base plate.