Abstract: An ultra-wide angle f-.theta. lens system comprising, in the order from the light beam deflector side, a first lens component having positive power, a second lens component having negative power, and a third lens component having positive power, the ultra-wide angle f-.theta. lens system being arranged to have an ultra-wide scanning angle widened to .+-.45.degree. and exhibiting an imaging performance of laser beam waist close to the diffraction limit in spite of the fact that the f-.theta. lens system comprises a small number of lenses.

Abstract: The present invention relates to an ocular comprising a first lens component of a positive single or cemented lens, a second lens component of a positive single lens, a third lens component of a biconcave lens and a fourth lens component of a positive single lens. The ocular is constituted of a triplet type lens system comprising as a basis the second through fourth lens components and, in addition, the positive single or cemented lens.

Abstract: An objective lens system for microscopes consisting of a front lens group comprising a positive lens component and a meniscus lens component having a concave surface on the image side, and a rear lens group comprising at least a meniscus cemented lens component, a positive lens component and at least one cemented three-element lens component. Said objective lens system is so designed as to have a large numerical aperture, secondary spectrum sufficiently minimized, a long working distance and curvature of field, coma etc. favorably corrected over a wide range of visual field.

Abstract: A microscope objective comprising a first, second, third, fourth and fifth lens components, in which the first lens component is a negative meniscus lens, the second lens component is a positive meniscus lens, the third and fourth lens components are positive cemented doublets and the fifth lens component is a negative cemented meniscus doublet, and for which the numerical aperture is large and the image becomes flat toward marginal portion.

Abstract: A lens mount for a microscope objective comprising a correcting ring, which is used for moving a part of lenses constituting the objective along the optical axis in order to correct deterioration of the image, and a friction band arranged round the outer surface of said correcting ring and made of material such as rubber so that said correcting ring can be easily rotated by rubbing said friction band by a finger bulb.

Abstract: An incident light fluorescence microscope comprising a dichroic mirror of the concave type to enable a person to observe a extremely bright, fog-free and clear image, by making small the incidence angle of the illuminating light to said dichroic mirror.