Abstract A lens for use in optical disc players comprising a single biconvex element having both surfaces aspheric. The refractive index, N D , of the element at 589.3 nm is 1.492 and at the same wavelength the Abbe V number is 57.4. At 800 nm the refractive index, N 800 , of the element is 1.48584. Each surface may be described by the equation: ##EQU1## wherein: X is the sag of the aspheric surface from a plane reference surface at a radial distance Y from the axis of the lens. ______________________________________ Surface 1 Surface 2
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C = 0.354021 -0.1557360
K = 0.0 -20.4938239
D = -0.2909441 × 10 -2 0.0
E = -0.5163209 × 10 -3 0.0
F = 0.5075886 × 10 -4 0.0
G = -0.1399892 × 10 -4 0.0
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Inventors
👤 Donald E. Oinen
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-30 12:52
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/02; G02B3/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
A lens for an optical disc player, the lens having an Abbe V number of 57.4 at 589.3 nm and comprising a single biconvex element with a refractive index, N 800 , of 1.8584, both surfaces of which being aspheres conforming to the equation: ##EQU4## wherein: X is the sag of the aspheric surface from a plane reference surface at a radial distance Y from the axis of the lens and K is the conic constant; D, E, F and G are aspheric higher order coefficients; C is the radius of the surface in the axial region, and the following values exist: ______________________________________
Surface 1 Surface 2
______________________________________
C = 0.354021 -0.1557360
K = 0.0 -20.4938239
D = -0.2909441 × 10.sup.-2
0.0
E = -0.5163209 × 10.sup.-3
0.0
F = 0.5075886 × 10.sup.-4
0.0
G = -0.1399892 × 10.sup.-4
0.0
______________________________________
Claim 2
Dependent Claim
141 words
A lens for an optical disc player, the lens having an Abbe V number of 57.4 at 589.3 nm and comprising a single biconvex element with a refractive index, N 800 , of 1.8584, both surfaces of which being aspheres conforming to the equation: ##EQU4## wherein: X is the sag of the aspheric surface from a plane reference surface at a radial distance Y from the axis of the lens and K is the conic constant; D, E, F and G are aspheric higher order coefficients; C is the radius of the surface in the axial region, and the following values exist: ______________________________________
Surface 1 Surface 2
______________________________________
C = 0.354021 -0.1557360
K = 0.0 -20.4938239
D = -0.2909441 × 10.sup.-2
0.0
E = -0.5163209 × 10.sup.-3
0.0
F = 0.5075886 × 10.sup.-4
0.0
G = -0.1399892 × 10.sup.-4
0.0
______________________________________