Patents by Inventor Katsuhito Harada

Katsuhito Harada has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5434665
    Abstract: A sample disposed in a graphite tube in a furnace is subjected to thermal treatment at successive stages, drying, ashing and atomization and atomic absorption due to an element contained in the sample is measured. Amounts of inert carrier gas supplied to the graphite tube are different for different samples. The carrier gas flow rate at each of the stages is varied so as to reduce influences of background when each of the samples is treated. The carrier gas flow rate is varied, depending on the magnitude of a background signal measured on the basis of light which has passed through the graphite tube.
    Type: Grant
    Filed: August 4, 1993
    Date of Patent: July 18, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Hayato Tobe, Katsuhito Harada
  • Patent number: 5235862
    Abstract: A sample handling apparatus includes a furnace which atomizes elements to be tested in a sample. A matrix modifier is added to the furnace. A quantity of the sample is subsequently added to the furnace. An additional quantity of the matrix modifier is then added into the furnace. The furnace is heated to atomization temperature to permit analysis of the sample to be tested.
    Type: Grant
    Filed: July 18, 1991
    Date of Patent: August 17, 1993
    Assignee: Hitachi, Ltd.
    Inventor: Katsuhito Harada
  • Patent number: 5108178
    Abstract: An atomic absorption spectrophotometer includes a sample-atomizing portion for ashing and atomizing a sample, a power source operable to supply electric current to the sample-atomizing portion, a controller for controlling the operation of the power source, a pair of pressure regulators for setting a flow rate of an inert gas according to an ashing step and an atomization step in the sample-atomizing portion, a pair of movable valves respectively provided downstream of and connected to the pair of pressure regulators, and a filter device provided between the pair of movable valves and the sample-atomizing portion. Either of the pair of movable valves is activated into open or closed condition in synchronism with the operation of the power source so as to select the flow rate of the inert gas into the sample-atomizing portion.
    Type: Grant
    Filed: March 29, 1990
    Date of Patent: April 28, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Konosuke Oishi, Katsuhito Harada, Masamichi Tsukada, Kazuo Moriya, Toyoharu Okumoto
  • Patent number: 5104220
    Abstract: An atomic absorption spectrophotometer comprising means for setting the ashing temperature for that of the element having the lowest ashing temperature; means for setting the atomizing temperature for that of the element having the highest atomizing temperature; and means for effecting background correction utilizing Zeeman effect.
    Type: Grant
    Filed: February 28, 1989
    Date of Patent: April 14, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Toyoharu Okumoto, Katsuhito Harada, Konosuke Oishi
  • Patent number: 5042946
    Abstract: An atomic absorption spectrophotometric apparatus, which includes a first light source emitting plural specific spectra by changing the current of the first light source into relatively small and large currents, a second light source emitting a continuous spectrum, an atomizer for atomizing a sample, a beam combiner for directing the spectrum emitted from the first light source and the second light source to the atomized sample, a detector for detecting the plural specific spectra and the continuous spectrum which passes through the atomized sample, and a computer for obtaining spectrum absorbances of the plural specific spectra and the continuous spectrum from the outputs of the detector and obtaining a concentration of a specific element on the basis of a combination of the spectrum absorbances.
    Type: Grant
    Filed: May 2, 1990
    Date of Patent: August 27, 1991
    Assignee: Hitachi, Ltd.
    Inventor: Katsuhito Harada
  • Patent number: 4890919
    Abstract: An atomic absorption spectrophotometer is disclosed in which, in order to detect the temperature of a graphite cuvette correctly on the basis of the radiation emitted from the inner wall of the graphite cuvette, the above radiation and the measuring light emitted from a hollow cathode lamp are both taken out by the same optical members, and then the radiation is separated from the measuring light, to be detected and used for measuring the temperature of the graphite cuvette.
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: January 2, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Masamichi Tsukada, Konosuke Oishi, Katsuhito Harada, Toyoharu Okumoto
  • Patent number: 4432643
    Abstract: An apparatus for atomizing a sample comprises a cuvette of heating material into which a sample is introduced, a pair of electrodes of supplying an electric current to the cuvette, thereby heating and atomizing the sample, supports of supporting the pair of the electrodes, a means for supplying light to the atomized sample and a means of slidably maintaining at least one of the pair of the electrodes against the cuvette in a predetermined range of contact pressures, where the heating temperature of the cuvette can be maintained constant with improved reproducibility of analytical values.
    Type: Grant
    Filed: March 18, 1981
    Date of Patent: February 21, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Hideaki Koizumi, Yosio Taiti, Kazuo Moriya, Katsuhito Harada, Kazuo Sato
  • Patent number: 4100446
    Abstract: In a tubular bulb filled with inert gas, a cathode and an anode are disposed opposite to each other. Electric discharge is caused between the electrodes to emit optical radiation. The bulb has a smaller diameter at the portion thereof which surrounds the electrodes than at the other portion of the bulb, and a magnet to establish magnetic field to cause Zeeman effect in the direction of the electric field between the electrodes is disposed near the portion of the bulb having the smaller diameter.
    Type: Grant
    Filed: May 30, 1974
    Date of Patent: July 11, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhito Harada, Hideaki Koizumi, Konosuke Oishi