摘要:
A composition has a durability to a sterilization treatment using vapor under high temperature and pressure and capable of transmitting or absorbing light. The composition comprises a group A including 15 to 23 mol % of lanthanum oxide, 3 to 8 mol % of gadolinium oxide, 3 to 8 mol % of tantalum oxide, and 8 mol % or less of yttrium oxide; a group B including 30 to 45 mol % of boron oxide, 20 mol % or less of silicon oxide, and 20 mol % or less of germanium oxide; zero mol % of alkaline metal oxide or alkaline earth metal oxide; and a group D including 0.3 to 15 mol % of niobium oxide and 3 to 15 mol % of zirconium oxide. A mol % ratio A/B between the group A and group B is 80% or more, and a dissolving-out rate of metal ion of the composition is 0.002×10−6 mol/hour or less per square centimeter. In case of applying the composition to an endoscope including an observation system and an illuminating system, an optical element disposed at the outer surface of the observation system and an optical element disposed at the outer surface of the illuminating system are formed of the composition.
摘要:
An endoscope optical system is capable of obtaining favorable endoscopic images at all times by overcoming the conventional disadvantages that diagnosis is hindered by image quality disturbance due to the increase in pixel density resulting from the reduction in pixel pitch of solid-state image pickup devices and also due to the conventional arrangement of an objective front optical element in an optical system having a short focal length or in an optical system having a large F-number. In an image pickup apparatus using a monochromatic high-density solid-state image pickup device in which the average pixel pitch (H+V)/2 of the pixel pitch H in the horizontal direction and the pixel pitch V in the vertical direction with respect to the monitor scanning line is not more than 4.65 μm, or using an interline type color high-density solid-state image pickup device in which the average pixel pitch (H+V)/2 is not more than 3.1 μm, the volume V1 of an air layer between a plane-parallel plate (F1) closest to the object side in the image pickup optical system and a piano-concave negative lens (L1) satisfies the following condition: V1
摘要:
A method of forming an image of detailed cilium wrapped by mucus which exists in the epithelial layer of a cellular structure of a bronchus, where the method includes the steps of: irradiating an illumination light to the epithelial layer; generating Fresnel reflected light; irradiating the Fresnel reflected light to an image pick-up optical system; enlarging the Fresnel reflected light by the image pick-up optical system so that the enlarged Fresnel reflected light can be received by the image pick-up element; scanning at a velocity which is more than the velocity of motion of the cilium by the image pick-up element; transmitting image information from the image pick-up element to an observable medium with the naked eye; and displaying the image of detailed cilium by the observable medium.