GB421620A - Improvements in magnifying lenses for reading purposes - Google Patents
Improvements in magnifying lenses for reading purposesInfo
- Publication number
- GB421620A GB421620A GB2043933A GB2043933A GB421620A GB 421620 A GB421620 A GB 421620A GB 2043933 A GB2043933 A GB 2043933A GB 2043933 A GB2043933 A GB 2043933A GB 421620 A GB421620 A GB 421620A
- Authority
- GB
- United Kingdom
- Prior art keywords
- face
- reading purposes
- magnifying
- magnifying lenses
- plane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B25/00—Eyepieces; Magnifying glasses
- G02B25/002—Magnifying glasses
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Abstract
421,620. Magnifying -lenses. BIRCHALL, H. J., Glenwood, Oaks Road, Shirley, Surrey. July 20, 1933, No. 20439. [Class 97 (i)] A magnifying lens for reading purposes has a convex front surface 2 and a plane rear surface 5, the surface 2 being part of a surface of revolution generated by the rotation of an arc of a circle 3, Fig. 7, about its chord 4 which lies in the plane face 5, so that sections of the curved surface by planes at right-angles to the line 4 are circular arcs, the radii of which diminish continuously from the centre towards each end. The face 5 is in the form of an elongated strip which is connected to the edges of the face 1 by bevelled surfaces 6 coated with an opaque substance to bring the strip 5 into greater prominence. Projections 8 are provided to raise the face 5 above the surface to be viewed.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2043933A GB421620A (en) | 1933-07-20 | 1933-07-20 | Improvements in magnifying lenses for reading purposes |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2043933A GB421620A (en) | 1933-07-20 | 1933-07-20 | Improvements in magnifying lenses for reading purposes |
Publications (1)
Publication Number | Publication Date |
---|---|
GB421620A true GB421620A (en) | 1934-12-27 |
Family
ID=10145965
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2043933A Expired GB421620A (en) | 1933-07-20 | 1933-07-20 | Improvements in magnifying lenses for reading purposes |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB421620A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2521558A (en) * | 1946-02-20 | 1950-09-05 | Alvarez Patent Corp | Magnifying picture viewing device |
US4949978A (en) * | 1988-11-25 | 1990-08-21 | David Berner | Magnifying device |
-
1933
- 1933-07-20 GB GB2043933A patent/GB421620A/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2521558A (en) * | 1946-02-20 | 1950-09-05 | Alvarez Patent Corp | Magnifying picture viewing device |
US4949978A (en) * | 1988-11-25 | 1990-08-21 | David Berner | Magnifying device |
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