Boots – shoes – and leggings
Patent
1985-10-25
1989-03-28
Lall, Parshotam S.
Boots, shoes, and leggings
364525, 36441301, 382 25, 33200, 33507, G02C 702, G06F 1546
Patent
active
048170240
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a spectacle-frame shape data producing method for producing spectacle lenses conforming to the shape of a spectacle frame.
BACKGROUND ART
Presently, the mode of supplying spectacle lenses in various countries of the world is broadly classified into two modes.
According to one of the modes, a spectacle shop transmits prescribed values and the kind of lenses to a lens maker's factory or a lens wholesale store to acquire raw lenses not subjected to edging, and the lenses are framed in a selected spectacle frame in the spectacle shop to complete the spectacles. This mode is principally employed in Japan, Southeast Asia, Europe, etc. and is called an uncut mode.
According to the other, an optometrist transmits prescribed values and the kind of lenses and position information of the prescribed values of the lenses in a selected spectacle frame, together with the specific spectacle frame, to a lens maker's factory, and, after production and framing of the lenses in the lens maker's factory, the glazed spectacles are sent back to the optometrist. This mode is principally employed in North America and is called a laboratory mode.
These two modes are frequently employed in parallel. Further, there is a type of spectacle shop which carries specific kinds of lenses although the mode is the uncut mode, and, also, there is a lens factory which carries specific kinds of frames although the mode is the laboratory mode. Thus, there is a case where the aforementioned classification is not necessarily applicable. At least, the laboratory mode differs definitely from the uncut mode in that a lens maker's factory obtains the kind and shape of a selected spectacle frame and can prepare spectacle lenses having a thickness most suitable to that spectacle frame.
This capability of proposing spectacle lenses having a thickness most suitable to a selected spectacle frame is significant chiefly in the case of (+) lenses. As is well knnown, a (+) lens has generally such a shape that it is thickest at the center and becomes progressively thinner toward the periphery thereof. Therefore, when the same peripheral thickness is set for lenses having the same degree, a lens having a larger outer diameter has a larger central thickness. The same applies to spectacle frames, and, generally, a larger spectacle frame requires a thicker lens.
However, in the uncut mode, only a few kinds or, at most, two or three kinds of outer diameters are commonly prepared for lenses of the same diameter and are not enough to closely deal with a variety of kinds of spectacle frames. Therefore, lenses having an outer diameter larger than that required must be used. When, for example, lenses having an original diameter of 60 to 70 mm is subjected to edging until they suit the dimensions and shape of a spectacle frame having an outer shape smaller than the lens diameter, the peripheral thickness (referred to hereinafter as an edge thickness) and the central thickness become larger than the edge thickness of the lenses before being subjected to the edging, in the case of convex lenses. When spectacles are made by such a method, especially, when lenses having a large original outer shape and a spectacle frame having a small size compared with the lenses are used to make spectacles, the glazed spectacles are provided with lenses having a vey large edge thickness and a very large central thickness. Thus, this results in the problem that the glazed spectacles are unnecessarily thick and heavy and also awkward.
As an attempt to correct the above problem as much as possible, there has been proposed a so-called outer-diameter specifying method according to which a spectacle shop measures a required minimum outer diameter of lenses to be mounted in a spectacle frame and specifies that diameter to a lens factory. However, this method is insufficient for application to lenses such as lenses for astigmia, prescribed prism lenses and progressive power ophthalmic lenses having different peripheral thicknesses depending on the direct
REFERENCES:
patent: 3534396 (1970-10-01), Hart
patent: 4361830 (1982-11-01), Honma et al.
patent: 4524419 (1985-06-01), Headlund et al.
patent: 4573121 (1986-02-01), Saigo et al.
patent: 4578768 (1986-03-01), Racine
patent: 4616107 (1976-10-01), Abb et al.
patent: 4713496 (1987-12-01), Kimura et al.
JP Abstract 57-158829, vol. 6, No. 265, p. 165, Appln. 56-44778, 9/82.
JP Abstract 58-38919, vol. 7, No. 121, p. 199, Appln. 56-137340, 3/83.
JP Abstract 59-13218, vol. 8, No. 101, p. 273, Appln. 57-122179, 1/84.
Hoya Corporation
Lall Parshotam S.
Lewen Bert J.
Ramirez Ellis B.
Sternberg Henry
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