Abstract: A catadioptric optical system (10, 110) capable of forming an image of an object. The system comprises a first optical axis (Z.sub.1) having a first end (12) and a second end (14), with a concave mirror (M.sub.C) arranged at the first end. A second surface (P.sub.2) orthogonal to the first optical axis is provided at the second end. A reflective surface (M) is arranged between the concave mirror and the second surface. A first imaging optical system (A) comprising a first plurality of lenses (L.sub.1 -L.sub.4) is arranged between the reflective surface and the concave mirror. A second imaging optical system (B) comprising a second plurality of lenses (L.sub.5 -L.sub.9) is arranged between the reflective surface and the second surface. The system further includes a second optical axis (Z.sub.2) intersecting the first optical axis at the reflective surface and having a first surface (P.sub.1) disposed along and orthogonal to the secondary optical axis.

Abstract: A zoom lens system is provided having a relatively small F-number, which remains nearly constant as the zoom lens system is moved from its wide-angle end to its telephoto end, and which provides an excellent imaging quality. The zoom lens system includes at least a first lens group G.sub.1 having a positive refractive power, and a second lens group G.sub.2 having a negative refractive power. The second lens group G.sub.2 moves uniformly toward the image while the first lens group G.sub.1 remains stationary. When the zoom lens system is moved from the wide-angle end to the telephoto end. The F-number is equal to or less than 2.1 over the entire zoom range.

Abstract: A shake-preventing correction optical system has in order from the object side a lens unit (Gf) fixed in a direction perpendicular to the optical axis and a shake-preventing correction lens unit (Gv) including a decentering lens unit arranged as movable in a direction substantially perpendicular to the optical axis, wherein the lens unit (Gf) has a first lens unit (G1) having a positive refractive power, a focusing lens unit (G2) having a negative refractive power and arranged to move along the optical axis to effect focusing to a near object, and a lens unit (G3a), and wherein the shake-preventing lens unit (Gv) includes the decentering lens unit (G3b) having a positive lens and a negative lens. The shake-preventing correction optical system has the decentering lens unit composed of a small number of constituent lens or lenses and has good imaging performance even upon shake-preventing correction.

Abstract: A microscope objective lens is provided as a semi-apochromatic microscope objective lens which has a magnification of about 40, has favorably corrected various kinds of aberration, and can also be used for observing fluorescence under downward radiation. The microscope objective lens comprises, successively from the object side, a positive meniscus lens component G1 having a concave surface directed onto the object side, a positive meniscus cemented lens component G2 having a concave surface directed onto the object side, a biconvex lens component G3, a cemented lens component G4 having, at least, a negative lens and a biconvex lens, and a negative meniscus cemented lens component G5 having a concave surface directed onto the image side, wherein the following conditions:0.1<r1/r3<0.3-30<f2/f1<-105<D/f<8.5are satisfied.

Abstract: A measuring apparatus in which two opposite sides of a load receiving plate to which a load is to be applied are coupled to two sides of an inner frame enclosing the load receiving plate by means of at least four inner beams. The measuring apparatus also comprises an outer frame enclosing the inner frame, two sides of which are coupled to other two sides of the inner frame by means of at least four outer beams, whereby the load receiving plate and inner frame are supported by the outer frame. Further, strain gauges are provided on the inner and outer beams, and strains of these beams are detected by the strain gauges and measured as electrically processed and amplified.

Abstract: The present invention provides a measuring apparatus comprising a load receiving plate, a frame member enclosing the load receiving plate, and at least four beams coupling the load receiving plate and the frame member to each other, thereby supporting the load receiving plate. The beams are so formed as to deflect at predetermined portions thereof in response to X-, Y- and Z-axial components of a force applied to the load receiving plate under the assumption that a direction perpendicular to the load receiving plate is taken as the Z-axial direction and directions perpendicular to each other in the horizontal plane of the load receiving plate are taken as the X- and Y-axial directions, respectively, and strain gauges are provided at predetermined portions of the beams.

Abstract: The present invention provides a catching head of apparatus for catching parts, having a tube expansible by a fluid such as air, etc. hermetically fixed at both the ends thereof to a hard base end and free end, respectively, of a core member. When in use, the tube of the catching head is expanded by air to catch a part or any other object to be handled. The one end of the tube attached to the free end of the core member is fitted as folded back to the free end of the core member. A passage is formed in the base end of the core member to supply air into the tube hermetically sealed.