Hitachi, Ltd.

Yoshio Maeda

Koichi Matsumoto

Kenji Fukuda

Isao Shindo

Fujiya Takahata

Tadashi Honkawa

Koji Nishiwaki

Tetuya Shinden

Seigo Kamitake

Koichi Yagai

Fluorescent dye is added to a sample including lymphatic cells stimulated by antic bodies to measure fluorescence polarization. The fluorescence polarization varies with time. The measurement is stopped after a predetermined measurement time, and the lymphatic cells are separated from the sample by filtering. In order to determine the fluorescence polarization in a filtering process, approximate equations of the reaction are determined based on the fluorescence polarization measured during the reaction process. Based on the approximate equations, the fluorescence polarization in the filtering process is calculated. The reaction process is approximated by both an approximate linear line and an approximate curve. A reaction data at a predetermined future time is calculated based on the two approximate functions so that a reliability of the resulting data is improved.

Fluorescence polarization analyzer

A wavelength reading apparatus for a monochromator comprises a monochromator utilizing a dispersion element for dispersing light in accordance with its wavelengths, a dispersion element driver unit for rotating the dispersion element to effect the tuning wavelength scanning operation of the monochromator and a wavelength counter for adding or subtracting a pulse, which is produced each time when the tuning wavelength of the monochromator changes by a predetermined wavelength increment, depending on whether the wavelength increases or decreases. The wavelength counter is set to a predetermined counting value, in response to a wavelength calibrating pulse produced when the tuning wavelength of the monochromator reaches a predetermined value, so that any counting value of the wavelength counter correctly represents the instant value of the tuning wavelength of the monochromator.

Wavelength reading apparatus for monochromator

A light signal entering a photo-electric converter means is interrupted at a certain interval of time. An electrical signal produced from the photo-electric converter means, after a predetermined amount of electrical signal is added to it, is A-D converted. The difference between the digital signal associated with the interruption of light to the photo-electric converter means and the digital signal associated with non-interruption of light to the photo-electric converter means is produced, which difference is proportional to the incident light signal. Even when the light entering the photo-electric converter means is very weak, the fact that a predetermined amount of electrical signal is added contributes to A-D conversion of good linearity. Even very weak light is thus A-D converted accurately. Noises and undesirable DC signal components contained in the two types of digital signals are offset by production of the difference.

Apparatus for converting light signals into digital electrical signals

Monochromatic light emitted from a monochromator is split into two light beams. These light beams are detected by a photodetector and converted into corresponding electric signals after having been transmitted, respectively, through a sample to be analyzed and a reference placed in the respective beam paths. The signal corresponding to the light beam transmitted through the sample and the signal corresponding to the light beam transmitted through the reference are converted into digital signals which are subsequently stored in respective digital storages or memories. The signal corresponding to the light beam transmitted through the reference is compared with a value in a predetermined range. The resultant value is then converted into an analog signal for operating a sensitivity regulator thereby to adjust the sensitivity of the photodetector. Thus, the signal corresponding to the light beam transmitted through the reference (reference light signal) is so controlled as to lie in a predetermined range. From the digital signals stored in the digital memory, ratio between the sample light signal and the reference light signal is arithmetically calculated by a digital processor unit for determining the transmittance of the sample. Since the reference light signal is prevented from significant variation and the calculation of the signal ratio is effected on the basis of digital technique, the measurement accuracy is remarkably enhanced.

Spectrophotometers with digital processing

Method for optically analyzing a specimen by using two light beams comprises steps of initiating automatically wavelength scanning operation when a predetermined time has elapsed after the switching-on of a power source, sampling a ratio between a reference light intensity and a specimen light intensity during the wavelength scanning operation when no specimen to be measured is placed in the sample cell, and storing signals derived from the sampling operation in a volatile memory. When the specimen is to be measured or analyzed, the measure signal representative of ratio between the reference light intensity and the specimen transmitting light intensity which are produced or the wavelength scanning operation proceeds is corrected by the corresponding signal read out from the volatile memory in accordance with the wavelength of the measure signal, and the corrected signals are processed as the error-free measure signal.

Method and apparatus for optically analyzing specimen by using two light

A control apparatus for driving a pulse motor which receives from a computer or the like a command signal indicative of the number of drive pulses to be applied to the pulse motor within a given time interval in order to drive the pulse motor at a given rotating speed produces, in response to the command signal, drive pulses equal in number to the commanded number within that time interval, preferably with uniform distribution, and drives the pulse motor in accordance with the drive pulses.

Control apparatus for driving a pulse motor

The present monochromator comprises a plurality of monochromator portions including one prism and at least one diffraction grating, the prism being arranged in the first or final portion. In order to cover a deviation of light having a required wavelength at an exit slit, resulting from the variation of refractive index of the prism due to the variation of temperature and from the rotational error of the prism and in order to increase the amount of exit light, the width of an entrance or exit slit adjacent to the prism is held always greater by a constant value a than an intermediate slit adjacent to the prism. The value a is selected to be equal to either a.sub.T or a.sub.r shown by the following expression or greater than it,

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Katsuta, Japan

Yoshio Maeda