Patent ID: 11874448
Assignee: SONY INTERACTIVE ENTERTAINMENT LLC
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 3:
4. A lens system, comprising:
a first Fresnel lens; and
a second Fresnel lens, wherein:
each of the first Fresnel lens and the second Fresnel lens includes a respective plurality of grooves that are concentrically formed,
as to each of the first Fresnel lens and the second Fresnel lens, both a pitch that is a distance between two adjacent grooves and a depth of each of the plurality of grooves vary with a distance from an optical axis that passes through a center of the lens system,
as to each of the first Fresnel lens and the second Fresnel lens, a distance from the optical axis and a pitch are defined as X (mm) and P (mm), respectively,
when 0 mm≤X≤18 mm, X and P satisfy following conditions:

P≤(−0.00039(X−18){circumflex over ( )}3+0.2)×1.5

P≥(−0.00039(X−18){circumflex over ( )}3+0.2)×0.5, and

the first Fresnel lens and the second Fresnel lens are disposed side by side in a direction of the optical axis.