US4251158A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Albada finder incorporating a range finder
Assignee: Olympus Corp
•
Filing: 1979-03-05
•
Granted: 1981-02-17
•
Expires: 1999-03-05
Abstract
Abstract An albada finder incorporating a range finder comprising a first negative lens component, a second thick negative lens component and a third positive lens component, said second lens component being split into two elements along a plane inclined with regard to the optical axis and a semitransparent surface being formed on said split surface.
Inventors
- 👤 Tadashi Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:51
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/14; G02B27/144; G03; G03B; G03B13/00; G03B13/02; G03B13/04; G03B13/06; G03B13/08; G03B13/16
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
90 words
An albada finder incorporating a range finder comprising a first negative lens component, a second thick negative lens component consisting of two elements which are split along a plane inclined with regard to the optical axis, a third positive lens component, a field mask formed on the surface of said third lens component, a reflecting mirror mounted on the surface of said second lens component and serving to reflect the rays coming from said field mask and a semitransparent surface formed on the inclined surface of said second lens component.
Claim 2
Dependent Claim
90 words
An albada finder incorporating a range finder comprising a first negative lens component, a second thick negative lens component consisting of two elements which are split along a plane inclined with regard to the optical axis, a third positive lens component, a field mask formed on the surface of said third lens component, a reflecting mirror mounted on the surface of said second lens component and serving to reflect the rays coming from said field mask and a semitransparent surface formed on the inclined surface of said second lens component.
Claim 3
Dependent Claim
58 words
An albada finder incorporating a range finder according to claim 1 wherein thickness d 3 of said second lens component satisfies the following condition: ##EQU2## wherein the reference symbol a represents height of the field ray and the reference symbol r 4 designates radius of curvature on the surface on the eyepiece lens of said second lens component.
References Cited (Backward Citations)
US3125623A
Cited
US2210191A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-17 | 1984-08-18 | 1985-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-17 | 1988-08-18 | 1989-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-17 | 1992-08-18 | 1993-02-17 | $7700.00 | Window Closed / Lapsed |