Abstract: A microscope objective lens system comprising a first lens unit which comprises a positive meniscus lens component having a concave surface on the object side and has a positive refractive power, a second lens unit which comprises a diverging cemented surface and has a positive refractive power, a third lens unit which comprises surfaces having strongly diverging functions and has a negative refractive power, and a fourth lens unit which has a negative refractive power; and configured so as to allow the second lens unit to be moved relatively to the first lens unit and the third lens unit in conjunction with thickness of a transparent plane parallel plate disposed between a surface of an object to be observed and the first lens unit, thereby correcting variations of aberrations caused due to changes in thickness of plane parallel plates.

Abstract: In a turret type of machine tool having a turret head which can be rotated for indexing to selectively index an arbitrary one of tool mounting members provided in a plurality of circumferential portions into a machining position which coincides with a predetermined radial direction, the construction of the turret head is simplified to reduce the cost and increase the reliability. A first supporting body is provided which is connected to a moving mechanism which advances or recedes the turret head along an axis of machining coinciding with the axial line of the tool mounting member at the machining position. A second supporting body which is movable along the axis of machining is supported on the first supporting body, and the turret head is rotatably supported on the second supporting body so as to be rotated for indexing. A spindle head is fixed to the first supporting body such that a spindle to be supported on the spindle head coincides with the axis of machining.