US3823320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-optic device for counting objects
Assignee: LEDOUX NV
•
Filing: 1972-09-07
•
Granted: 1974-07-09
•
Expires: 1992-09-07
Abstract
Abstract A ribbon-shaped beam of light is projected onto an objective lens, and a light transducer has a sensitive surface onto which the ribbon-shaped beam of light is focussed by the lens as a small light spot. The ribbon-shaped beam of light extends transverse to and intersects the path of movement of the objects. Means, arranged across the path of the ribbon-shaped beam maintains a predetermined gradation in light density across the width of the beam.
Inventors
- 👤 J Ledoux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:20
CPC Classifications
G; G06; G06M; G06M1/00; G06M1/08; G06M1/10; G06M1/101
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
An electro-optic device for counting a succession of moving objects, comprising an objective lens, a light source arranged to transmit a beam of light across the path of travel of the objects and through the objective lens, and a light transducer having a sensitive surface onto which the light beam is focussed by the lens, wherein the improvement comprises a screen arranged between the light source and the objective lens, having a rectangular slit which selects from the light beam a narrow rectangular beam extending transversely across the path of the moving objects and a filter of graded density arranged to intercept the light forming the narrow rectangular beam, the image of the rectangular beam leaving the objective lens being of non-uniform intensity in the absence of the filter but being of substantially uniform intensity with the filter present and means for passing a succession of moving objects between the light source and the filter.
Claim 2
Dependent Claim
155 words
An electro-optic device for counting a succession of moving objects, comprising an objective lens, a light source arranged to transmit a beam of light across the path of travel of the objects and through the objective lens, and a light transducer having a sensitive surface onto which the light beam is focussed by the lens, wherein the improvement comprises a screen arranged between the light source and the objective lens, having a rectangular slit which selects from the light beam a narrow rectangular beam extending transversely across the path of the moving objects and a filter of graded density arranged to intercept the light forming the narrow rectangular beam, the image of the rectangular beam leaving the objective lens being of non-uniform intensity in the absence of the filter but being of substantially uniform intensity with the filter present and means for passing a succession of moving objects between the light source and the filter.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |