US3675558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved optical system for a single lens reflex camera
Assignee: Minolta Co Ltd
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Filing: 1969-10-10
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Granted: 1972-07-11
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Expires: 1989-10-10
Abstract
Abstract A single lens reflex camera in which an external scale for adjusting the focus or shutter of a camera is visible with the object image in a viewfinder. Between the scale and a viewfinder there are provided a pentagonal prism and a convergent lens for forming a real image of the scale at the viewfinder eyepiece.
Inventors
- 👤 Yoshio Kuramoto
- 👤 Shotaro Inagaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:37
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/02; G03B19/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
118 words
In a single lens reflex camera including a viewfinder having a focusing plate, a pentagonal prism and an eyepiece, and an adjustable setting member having a scale external to the viewfinder, the combination comprising: optical transmitting means for transmitting an image of the scale to said pentagonal prism, light converging means for forming a real image of said scale through said pentagonal prism at a location which is substantially the same optical distance from said eyepiece as the optical distance from said eyepiece to said focusing plate, reflecting means for directing the real image of said scale to said eyepiece through said pentagonal prism, and said reflecting means is mounted beneath the base face of said pentagonal prism.
Claim 2
Dependent Claim
118 words
In a single lens reflex camera including a viewfinder having a focusing plate, a pentagonal prism and an eyepiece, and an adjustable setting member having a scale external to the viewfinder, the combination comprising: optical transmitting means for transmitting an image of the scale to said pentagonal prism, light converging means for forming a real image of said scale through said pentagonal prism at a location which is substantially the same optical distance from said eyepiece as the optical distance from said eyepiece to said focusing plate, reflecting means for directing the real image of said scale to said eyepiece through said pentagonal prism, and said reflecting means is mounted beneath the base face of said pentagonal prism.
Claim 3
Dependent Claim
122 words
In a single lens reflex camera including a viewfinder having a focusing plate, a pentagonal prism and an eyepiece, and an adjustable setting member having a scale external to the viewfinder, the combination comprising: optical transmitting means for transmitting an image of the scale to said pentagonal prism, light converging means for forming a real image of said scale through said pentagonal prism at a location which is substantially the same optical distance from said eyepiece as the optical distance from said eyepiece to said focusing plate, reflecting means for directing the real image of said scale to said eyepiece through said pentagonal prism, and said means for reflecting is a small reflective surface formed on a portion of said base face.
Claim 4
Dependent Claim
122 words
In a single lens reflex camera including a viewfinder having a focusing plate, a pentagonal prism and an eyepiece, and an adjustable setting member having a scale external to the viewfinder, the combination comprising: optical transmitting means for transmitting an image of the scale to said pentagonal prism, light converging means for forming a real image of said scale through said pentagonal prism at a location which is substantially the same optical distance from said eyepiece as the optical distance from said eyepiece to said focusing plate, reflecting means for directing the real image of said scale to said eyepiece through said pentagonal prism, and said means for reflecting is a small reflective surface formed on a portion of said base face.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |