Hitachi, Ltd.

Hitachi Denshi Kabushiki Kaisha

Manabu Yamamoto

Masaru Ito

Seiichi Murayama

Kounosuke Oishi

Kunifusa Kayama

Masahiro Ojima

Makoto Yasuda

Shuhei Tanaka

Makoto Watanabe

Kounosuke Ohishi

In an autofocus system in which the image definition of an object to be picked up is detected by image sensor means disposed on a light path of an image-forming optical system and converted into electric signals, and the image-forming position of the image-forming optical system is controlled by using the electric signals, a plurality of electric signals representative of image definitions are obtained from a main image sensor and at least one sub-image sensor which are provided at optically different positions on the light path and subjected to a predetermined logical judgement processing to produce a focus control signal. The position of the image-forming optical system is controlled by the focus control signal. When the sub-image sensor is movably supported and the light path length between the image-forming optical system and the sub-image sensor is varied by changing the position of the sub-image sensor, a signal representative of the position of the sub-image sensor is also subjected to a predetermined logical judgement processing and used for controlling the position of the sub-image sensor.

Autofocus system

Apparatus for detecting magneto-optical anisotropy

In measuring a change in the polarization state of light attributed to magnetooptic anisotropy, a means for generating optic anisotropy is added to a light source or onto an optical path extending from the light source to a polarization analyzer. This allows high precision analysis of the polarization state of light emergent from the polarization analyzer.

Method and apparatus for measuring magnetooptic anisotropy

This application discloses a spectrophotometer employing a magneto-optic effect which enables quantitative analysis of a sample to be measured by a double beam method. In performing the double beam method for analyzing the sample, a magnetic field is applied to the sample along with linearly polarized light from a light source, the forward scattered light scattered by the sample atoms and the incident linearly polarized light from the sample are converted into two cross-polarized beams of light using an analyzer, and these two beams of cross-polarized light are spectrally analyzed by a single dispersive element. The spectrophotometer of the invention provides an arrangement such that the plane defined by the above-mentioned two beams of light is perpendicular to the plane of dispersion of the dispersive element, and the two beams of light so dispersed are independently detected by separate detectors.

Spectrophotometer employing magneto-optic effect

A magneto-optic spectrophotometer for detection or identification of atoms or molecules contained in the sample by utilizing phenomena of birefringence or rotation of polarization caused by the atoms or the molecules in a magnetic field is constructed as follows. Linearly polarized lights are incident on a space where atoms or molecules to be detected exist in a magnetic field. The lights having passed through said space are separated into two beams of lights of polarization components perpendicular and parallel to the polarization of the incident lights. The perpendicular components are used as the signal lights, and the parallel components the reference lights. The signal lights and the reference lights are spectrally analyzed by a wavelength selector in which a signal light and a reference light of a wavelength to be selected are incident on an identical dispersive element. The signal lights and the reference lights are detected by respective detectors. Then, the ratios of the outputs of the signal light detectors to the outputs of the reference light detectors are obtained. By this construction the intensities of the scattered lights by atoms or molecules to be detected can precisely be measured.

Magneto-optic spectrophotometer

A high frequency discharge lamp for a spectral-line source includes a discharge envelope in which a substance contributive to the emission of desired spectral lines is contained and in which one electrode is included, the discharge envelope being made of a material, such as quartz, which is electrically insulating and capable of transmitting the spectral lines. A cylindrical metallic container surrounds the discharge envelope and has at a part thereof an opening for taking out the spectral lines. There is further provided means for applying a high-frequency voltage between the electrode and the metallic container.

High frequency discharge lamp for a spectral-line source

A tunable laser is disclosed in which a plurality of laser beams different from one another in wavelength and polarization can be simultaneously oscillated. The tunable laser is advantageous among others in that an atomic absorption spectroscopic analysis can be carried out with very high sensitivity when it is used as, for example, a light source for two-wavelength measurement in the atomic absorption spectroscopic analysis.

Growing community of inventors

Odawara, Japan

Manabu Yamamoto