EP0722106A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Viewfinder optical system
Assignee: Canon Inc
•
Filing: 1996-01-10
•
Granted: —
•
Expires: 2016-01-10
Abstract
Abstract A compact magnification-varying viewfinder optical system includes an objective lens unit for forming a primary image, the objective lens unit having at least one curved reflection surface arranged to reflect a light flux and a lens surface, and an eyepiece lens unit for observing the primary image, wherein an optical power is imparted to the curved reflection surface.
Inventors
- 👤 Takeshi Koyama
- 👤 Yasunori Murata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:52
CPC Classifications
G; G03; G03B; G03B13/00; G02; G02B; G02B15/00; G02B15/14; G02B15/16; G02B15/177; G02B23/00; G02B23/14; G02B23/145
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
45 words
A viewfinder optical system comprising: an objective lens unit for forming a primary image, said objective lens unit having at least one curved reflection surface arranged to reflect a light flux and a lens surface; and an eyepiece lens unit for observing the primary image.
Claim 2
Dependent Claim
28 words
A viewfinder optical system according to claim 1, wherein said curved reflection surface has a concave shape with respect to a direction in which the light flux enters.
Claim 3
Dependent Claim
28 words
A viewfinder optical system according to claim 1, wherein said curved reflection surface has a convex shape with respect to a direction in which the light flux enters.
Claim 4
Dependent Claim
58 words
A viewfinder optical system according to claim 1, wherein said objective lens unit includes, in order in a direction in which the light flux advances, a plurality of lens units and a prism unit having an entrance surface for having the light flux incident thereon, a reflection surface for reflecting the light flux and said curved reflection surface.
Claim 5
Dependent Claim
47 words
A viewfinder optical system according to claim 4, wherein said reflection surface has a convex shape with respect to a direction in which the light flux enters, and said curved reflection surface has a concave shape with respect to the direction in which the light flux enters.
Claim 6
Dependent Claim
60 words
A viewfinder optical system according to claim 1, wherein said objective lens unit includes, in order in a direction in which the light flux advances, a plurality of lens units and a prism unit having an entrance surface for having the light flux incident thereon, said curved reflection surface and a total reflection surface for totally reflecting the light flux.
Claim 7
Dependent Claim
18 words
A viewfinder optical system according to claim 1, wherein said curved reflection surface has no rotationally symmetric axis.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.