Patent US3583813A successfully refreshed from Google Patents.
US3583813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spectrophotometer
Assignee: SHIMADZU SUSAKUSHO Ltd
•
Filing: 1969-09-25
•
Granted: 1971-06-08
•
Expires: 1989-09-25
Abstract
Abstract A spectrophotometer having a monochromatic light source, a prism, a slit for varying the amount of light, a beam splitting device, a photosensor and amplifier for each split beam, an attenuator for one beam and a level adjuster for the other, a ratio recorder with a double-throw switch for recording positive or negative readings, and a control mechanism operable on a signal related to the attenuated light to widen or narrow the slit.
Inventors
- 👤 Kazuo Shibata
- 👤 Yoshio Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:39
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/42
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
25 words
The spectrophotometer as defined in claim 1, further including means positioned between said beam splitting means and said sample cell for attentuating said second beam.
References Cited (Backward Citations)
US3123660A
Cited
US2437323A
Cited
GB869194A
Cited
US3183764A
Cited
US3334537A
Cited
US3459479A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |