Abstract: An objective lens system for endoscopes comprising, in the order from the object side, a first lens component having a negative refractive power, a second lens component having a positive refractive power, an aperture stop arranged right after the second lens component, and a rear lens unit comprising a third lens component designed as a cemented doublet consisting of a lens element having a positive refractive power and a lens element having a negative refractive power. Said objective lens system for endoscopes has a wide field angle, a compact design, a small number of lens elements and favorably corrected aberrations.
Abstract: A lens system is provided which includes two lens units. The first lens unit includes two meniscus lenses whose concave surfaces face each other and the second lens unit has a positive power. The system can be configured to have a wide field of view and/or to be telecentric. In its basic form, a well-corrected lens having a relatively large aperture and field of view is achieved through the use of only three lens elements.
Abstract: To easily correct color shading merely by adjusting the arrangement of an optical system. A light beam incident on a three prism type color separation optical system 1 having photographic devices 7, 8, 9 and guided to the photographic devices, is effectively telecentric on the side of the photographic devices.
Abstract: An objective optical system for endoscopes comprising, in the order from the object side, a front negative lens unit, an aperture stop, a positive lens unit comprising at least one positive lens component, and an infrared cut filter arranged immediately before said aperture stop, said objective optical system being adapted so as to allow rays to be incident on said filter at heights lower than the outside circumference of said filter.
Abstract: Source of laser radiation for a printer includes at least one laser diode array and an optical system which is telecentric in at least one azimuth for imaging the near field distribution from the laser diode array(s) on a recording medium.
Abstract: Modular illumination system for transmitted-light microscopes, embodying the Koehler illumination principle, and usable on microscopes of short or long optical transmission length, including a telecentering lens disposed in the light beam path defined according to Koehler between the luminous field diaphragm and the aperture diaphragm and imaging the luminous field diaphragm at infinity the telecentering lens is displaceable, preferably perpendicularly to the optical axis.
April 11, 1990
Date of Patent:
August 4, 1992
Jenoptik Jena GmbH
Joachim Bergner, Burkhard Bufe, Hubert Wahl
Abstract: A diffraction limited, f/6.0, 71.0 mm focal length telecentric scan lens which is color-corrected for 780 nm, 830 nm and 890 nm wavelengths. The lens includes, in succession from a side of incident light:a first negative meniscus lens element, concave toward the incident light side;a second positive meniscus lens element, concave toward the incident light side;a first plano-convex lens element, convex away from the incident light side;a second plano-convex lens element, convex toward the incident light side;a first cemented doublet including bi-concave and plano-convex lens elements, the cemented surface convex toward the incident light side; anda second cemented doublet including plano-concave and plano-convex lens elements, the cemented surface convex toward the incident light side.
March 28, 1991
Date of Patent:
February 11, 1992
Minnesota Mining and Manufacturing Company
Abstract: An exposure apparatus for use in fabricating a printed circuit board. A thermally-written liquid-crystal light valve is provided in which a pattern is formed by opaque portions and transparent portions. A writing optical system directs a heating spot light onto the light valve. The light valve and/or the heating spot light is movable, relative to the other. A projecting optical system is arranged which transmits a luminous flux emitted from a light source, through a liquid-crystal layer within the liquid-crystal light valve. The projecting optical system illuminates a subject with the transmitted luminous flux.
Abstract: A zoom lens is described for an electronic camera for still pictures, comprising a front group (G.sub.1), a variator group (G.sub.2) and a main group (G.sub.4). The lens is designed in such a manner that the sum of the spherical aberrations of the front group and the variator group is constant throughout the zoom range and is adapted to that of the main group.
Abstract: An optical scanning system has a deflector for deflecting a beam emitted from a light source portion, a telecentric scanning lens for focusing the deflected beam onto a scanning surface, a beam splitter for splitting a beam reflected by the scanning surface on an optical path between the deflector and the light source portion from an outgoing optical path, and a focus point detector for receiving the beam split by the beam splitter and detecting a focused state of the beam on the scanning surface.
Abstract: An optical system for endoscopes so adapted as to be usable with video endoscopes, comprising an imaging lens system equipped with an aperture stop and a field lens component arranged on the image side thereof, and so designed as to prevent the color shading from being produced by selecting an adequate focal length for the field lens component.