US4082457A
Expired / Lapsed
US
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Leukocyte detector
Assignee: Hitachi Ltd
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Filing: 1976-03-08
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Granted: 1978-04-04
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Expires: 1996-03-08
Abstract
Abstract A leukocyte detector comprises a first and a second filter means adapted to select color components with different wave lengths, or green and blue color components, respectively, from the microscopic image of a stained blood smear, a first and a second opto-electric converter means for converting the transmitted light from said first and second filter means into corresponding electrical signals, a subtractor for subtracting the outputs from said first and second opto-electric converter means, and a comparator which compares the output of said subtractor with the predetermined threshold limit value.
Inventors
- 👤 Hideki Kohno
- 👤 Akihide Hashizume
- 👤 Shinji Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:57
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/14; G01N15/1468; G01N15/1429; G01N15/1433
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
172 words
A leukocyte detector comprising: first means for resolving the entire microscopic image of a stained blood smear, each portion of said image being simultaneously observed, into respective spectral components with different wavelengths contained within at least the wavelength ranges 420 - 440 μm and 520 - 570 μm; second means for measuring the light quantities of said respective spectral components; third means for making a prescribed operational calculation by using as a variable each light quantity obtained from said second means; and fourth means for comparing the result of the calculation by said third means with a predetermined threshold limit value; whereby the presence of leukocytes is indicated by the output from said fourth means; and wherein said third means comprises fifth means for calculating the abscissa and ordinate on a chromaticity diagram from the determined light quantities of the respective wave lengths, and sixth means for calculating the sum of the outputs from said fifth means, and wherein the output from said sixth means is compared with said threshold limit value.
Claim 2
Dependent Claim
172 words
A leukocyte detector comprising: first means for resolving the entire microscopic image of a stained blood smear, each portion of said image being simultaneously observed, into respective spectral components with different wavelengths contained within at least the wavelength ranges 420 - 440 μm and 520 - 570 μm; second means for measuring the light quantities of said respective spectral components; third means for making a prescribed operational calculation by using as a variable each light quantity obtained from said second means; and fourth means for comparing the result of the calculation by said third means with a predetermined threshold limit value; whereby the presence of leukocytes is indicated by the output from said fourth means; and wherein said third means comprises fifth means for calculating the abscissa and ordinate on a chromaticity diagram from the determined light quantities of the respective wave lengths, and sixth means for calculating the sum of the outputs from said fifth means, and wherein the output from said sixth means is compared with said threshold limit value.
References Cited (Backward Citations)
US3827804A
Cited
US3819913A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |