Abstract: An optical element includes a multilayer film which has a first transmittance characteristic in a first wavelength region, and has a second transmittance characteristic in a second wavelength region existing at the side where a wavelength is longer than that of the first wavelength region. The multilayer film has a transmittance characteristic where a first peak with a maximum transmittance exists in the second wavelength region.

Abstract: A microscope includes an optical element provided with an anti-reflection film applied thereto. The anti-reflection film has the following layered structure: having first to sixth layers of films, in order from the surface of the optical element, formed of a high-refractive-index material for each of the first, third and fifth layers, a low-refractive-index material or a middle-refractive-index material for each of the second and fourth layers, and a low-refractive-index material for the sixth layer, with a range of the optical film-thickness nd of each layer in reference to the design wavelength ? being “(0.13˜0.35)×?/4” for the first layer, “(0.18˜0.75)×?/4” for the second layer, “(0.28˜2.31)×?/4” for the third layer, “(0.26˜0.92)×?/4” for the fourth layer, “(0.20˜0.37)×?/4” for the fifth layer, and “(1.09˜1.18)×?/4” for the sixth layer.

Abstract: A microscope includes an optical element provided with an anti-reflection film applied thereto. The anti-reflection film has the following layered structure: having first to sixth layers of films, in order from the surface of the optical element, formed of a high-refractive-index material for each of the first, third and fifth layers, a low-refractive-index material or a middle-refractive-index material for each of the second and fourth layers, and a low-refractive-index material for the sixth layer, with a range of the optical film-thickness nd of each layer in reference to the design wavelength ? being “(0.13˜0.35)×?/4” for the first layer, “(0.18˜0.75)×?/4” for the second layer, “(0.28˜2.31)×?/4” for the third layer, “(0.26˜0.92)×60 /4” for the fourth layer, “(0.20˜0.37)×?/4” for the fifth layer, and “(1.09˜1.18)×?/4” for the sixth layer.

Abstract: A microscope includes an optical element provided with an anti-reflection film applied thereto. The anti-reflection film has the following layered structure: having first to sixth layers of films, in order from the surface of the optical element, formed of a high-refractive-index material for each of the first, third and fifth layers, a low-refractive-index material or a middle-refractive-index material for each of the second and fourth layers, and a low-refractive-index material for the sixth layer, with a range of the optical film-thickness nd of each layer in reference to the design wavelength ? being “(0.13˜0.35)×?/4” for the first layer, “(0.18˜0.75)×?/4” for the second layer, “(0.28˜2.31)×?/4” for the third layer, “(0.26˜0.92)×?/4” for the fourth layer, “(0.20˜0.37)×?/4” for the fifth layer, and “(1.09˜1.18)×?/4” for the sixth layer.

Abstract: A fluorescence observing apparatus has an excitation filter unit for transmitting only exciting light with particular wavelengths, of illuminating light, and an absorption filter unit for transmitting only fluorescent light produced from a specimen by irradiating the specimen with the exciting light to block the exciting light. In this case, the space between the half-value wavelength on the long-wavelength side of the excitation filter unit and the half-value wavelength on the short-wavelength side of the absorption filter unit is in the range of 6–12 nm, and variations in the half-value wavelengths of the excitation filter unit and the absorption filter unit where humidity is changed from 10% to 95% are within 0.5 nm. Whereby, faint fluorescent light is efficiently taken out and the observation can be made.

Abstract: A microscope includes an optical element provided with an anti-reflection film applied thereto. The anti-reflection film has the following layered structure: having first to sixth layers of films, in order from the surface of the optical element, formed of a high-refractive-index material for each of the first, third and fifth layers, a low-refractive-index material or a middle-refractive-index material for each of the second and fourth layers, and a low-refractive-index material for the sixth layer, with a range of the optical film-thickness nd of each layer in reference to the design wavelength ? being “(0.13˜0.35)×?/4” for the first layer, “(0.18˜0.75)×?/4” for the second layer, “(0.28˜2.31)×?/4” for the third layer, “(0.26˜0.92)×?/4” for the fourth layer, “(0.20˜0.37)×?/4” for the fifth layer, and “(1.09˜1.18)×?/4” for the sixth layer.

Abstract: A fluorescence observing apparatus has an excitation filter unit for transmitting only exciting light with particular wavelengths, of illuminating light, and an absorption filter unit for transmitting only fluorescent light produced from a specimen by irradiating the specimen with the exciting light to block the exciting light. In this case, the space between the half-value wavelength on the long-wavelength side of the excitation filter unit and the half-value wavelength on the short-wavelength side of the absorption filter unit is in the range of 6-12 nm, and variations in the half-value wavelengths of the excitation filter unit and the absorption filter unit where humidity is changed from 10% to 95% are within 0.5 nm. Whereby, faint fluorescent light is efficiently taken out and the observation can be made.

Abstract: The nonaqueous solvent employed in drying as a final step of cleaning is regenerated. The nonaqueous solvent is contacted with a separation fluid having low compatibility with the nonaqueous solvent and high compatibility with a hydrophilic solvent to cause the hydrophilic solvent contained in the nonaqueous solvent to be absorbed in the separation fluid, thereby regenerating the nonaqueous solvent. When the hydrophilic solvent is an alcohol, a low-molecular-weight silicone compound and demineralized water may be used as the nonaqueous solvent and the separation fluid, respectively, in which the silicone compound can be regenerated to a purity of 99.0 to 99.8% so that the silicone compound can be recycled for use in the drying.

Abstract: A cleaning and drying solvent is disclosed which has excellent cleaning power and drying property and finds uses as a hand-cleaning agent, a precise cleaning agent and a drying agent for industrial parts. Since it does not contain halogens causing the depletion of the ozone layer, it is available as a solvent replacing freon. The cleaning and drying solvent is composed of a siloxane compound, in particular, hexamethyldisiloxane, an azeotropic or azeotrope-like composition of hexamethyldisiloxane and a lower alcohol, or a mixture of hexamethyldisiloxane and each of ketones, carboxylic esters, low molecular saturated hydrocarbons and low molecular alcohols.

Abstract: The nonaqueous solvent employed in drying as a final step of cleaning is regenerated. The nonaqueous solvent is contacted with a separation fluid having low compatibility with the nonaqueous solvent and high compatibility with a hydrophilic solvent to cause the hydrophilic solvent contained in the nonaqueous solvent to be absorbed in the separation fluid, thereby regenerating the nonaqueous solvent. When the hydrophilic solvent is an alcohol, a low-molecular-weight silicone compound and demineralized water may be used as the nonaqueous solvent and the separation fluid, respectively, in which the silicone compound can be regenerated to a purity of 99.0 to 99.8% so that the silicone compound can be recycled for use in the drying.