Nikon Corporation

Tdk Corporation

Nikon Vision Co., Ltd.

Jun Kawakami

Hisashi Shiozawa

Kouichi Tsukihara

Yutaka Ichihara

Eiji Takegami

Yasuaki Ishikawa

Hitoshi Kawai

Takeshi Kamono

Mikihiko Ishii

Yasushi Fukutomi

Akira Ishida

Katsunori Tomita

Satoru Okazaki

Koichi Watanabe

Hitohsi Kawai

There are provided a reticle, a reticle unit, and an optical apparatus, such as a rifle scope, each having a novel configuration that allows formation of a desired pattern. In a reticleAon which a pattern that serves as an indicator when an object under observation is visually recognized is formed, the pattern is formed of protruding sectionsandprovided on a pattern formation surfaceof a plate-shaped optical member. The protruding sectionsandare each formed of a plurality of protruding ridges(structural elements) extending in the lengthwise direction of a line that forms the pattern in parallel to the widthwise direction of the line. The protruding ridgeseach have an inclining surfaceinclining with respect to the optical path of an observation optical path, and the inclination angle of the inclining surface with respect to the optical axis Z is so set at an angle that causes light incident via an objective lens to be deflected to exit out of the observation optical path.

Reticle, reticle unit, rifle scope, and optical apparatus

A DC-DC converter is configured with a voltage-source power converter at a primary side of a transformer, a current-source power converter at a secondary side of the transformer, and a controller. First and second voltage detection circuits respectively detect first and second voltages of the voltage-source and the current-source power converters. A current detection circuit detects an input-output current of the current-source power converter. The controller controls the voltage-source and the current-source power converters to transfer power between the primary side and the secondary side of the transformer. The controller includes a calculation unit that performs calculations based on the first voltage, the second voltage and the input-output current, and a table unit that include a plurality of parameter sets. The calculation unit performs the calculations based on one of the plurality of parameter sets that is selected from the table unit.

DC-DC converter

A point diffraction interference measuring method comprises forming a substantially ideal spherical wave by using a point light source-generating unit, allowing a light flux composed of the spherical wave to pass through a test sample, thereafter dividing the light flux into two light fluxes by using an optical path-dividing element, allowing one light flux of the divided light fluxes to pass through a pinholeto covert the one light flux into a reference light beam which is a substantially ideal spherical wave, and detecting interference fringes generated by causing interference between the reference light beam and a measuring light beam which is the other light flux of the divided light fluxes. The wavefront aberration of the test sample can be measured by observing the interference fringes without being affected by the disturbance which would be otherwise caused by any system vibration or the like.

Method and apparatus for point diffraction interferometry

Both the optical distance of the detected-light light path and the optical distance of the reference-light light path are simultaneously varied according to respective specified patterns, so that differences are created between the period of variation in the intensity of the required signal component (in the interference signals) and the periods of variation in the intensities of the coherent noise components. When the modulation scanning procedure is performed, the phase difference between the detected light and reference light in a specified state is determined as shape information for the above-mentioned detected surface on the basis of the interference signals output from the light-receiving element. As a result, it is possible to securely reduce the effects of coherent noise components generated as a result of the interference of specified noise light that has passed through at least portions of the detected-light light path and reference-light light path with the detected light or reference light.

Method for measuring interference and apparatus for measuring interference

A second harmonic generation (SHG) device is used for conversion of wavelength. The direction of polarization of light beams is suitably rotated by a direction-of-polarization rotating unit, for example by 45.degree., and thereafter these light beams are guided into the SHG device. This can minimize attenuation of intensity of light beam due to conversion of wavelength. Hence, using this direction-of-polarization rotating unit in the apparatus for measuring the medium, the intensity of light being incident upon the photodetector can be increased, whereby the refractive index of the medium can be measured more accurately than by the conventional apparatus.

Apparatus for measuring refractive index of medium using light,

The displacement of the stage of an exposure apparatus can be measured by obtaining the phase difference between a light beam reflected by a stationary mirror and a light beam reflected by a movable mirror placed on the stage. This apparatus calculates the position data of the stage at second time by using the position data of the stage at first time which is measured by using first and second frequencies, the position data of the stage at the first time which is measured by using a third frequency, and the position data of the stage at the second time which is measured by using the third frequency.

Interferometric apparatus for measuring a physical value

The present invention relates to an optical interference measuring apparatus and method for measuring displacement of an object. The apparatus and method reduces the displacement-measurement error caused by changes of the refractive index of the atmosphere or the like, in a measurement optical path and a reference optical path, by suppressing crosstalk caused by unfavorable mixing of reference light and measurement light with each other, thereby improving accuracy in the measurement. The apparatus produces interference between a measurement light beam and a reference light beam. The measurement light is propagated through a measurement optical path including a measurement reflector, which is at least movable along the measurement optical path. The reference light is propagated through a reference optical path including a reference reflector. The interference occurs in a predetermined interference system, whereby the displacement of the measurement reflector can be measured. The apparatus, especially, comprises a light path separating system for spatially separating from each other the optical path from the measurement reflector to the interference system, through which the measurement light is propagated, and the optical path from the reference reflector to the interference system, through which the reference light is propagated.

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Mito, Japan

Jun Kawakami