FRESNEL LENS AND MANUFACTURING METHOD FOR FRESNEL LENS

• US 20180372925A1
• Filed: 02/06/2017
• Published: 12/27/2018
• Est. Priority Date: 02/09/2016
• Status: Active Grant

• Current Assignee: Sony Interactive Entertainment Inc. (Sony Group Corp.)
• Original Assignee: Sony Interactive Entertainment Inc. (Sony Group Corp.)
• Inventors: TADA, Shotaro, ISHIOKA, Manabu, KUSUNOKI, Toshihiro
• Granted Patent: US 10,641,931 B2
• Time in Patent Office: Days
• CPC Class Codes: C23C 14/04 Coating on selected surface areas, e.g. using masks
• CPC Class Codes: C23C 14/5873 Removal of material
• CPC Class Codes: F21V 5/045 the lens having discontinuous faces, e.g. Fresnel lenses
• CPC Class Codes: G02B 3/00 Simple or compound lenses
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876

Abstract

There are provided a Fresnel lens and a method of manufacturing the Fresnel lens which can suppress a flare which is generated in an image visually recognized through the Fresnel lens so as to extend toward a center of a lens. A lens surface and a non-lens surface are formed in each of lens portions. The non-lens surface includes a rise surface and a coupling surface. The rise surface is a surface along an optical axis of a Fresnel lens. The coupling surface is a surface which is formed on a top portion of each of the lens portions and couples the lens surface of the lens portion and the rise surface of the lens portion to each other, and which has a width extending in a radial direction of the Fresnel lens. A light absorbing portion is provided in a position along the optical axis of the Fresnel lens which passes through the coupling surface.

Claims

1. A Fresnel lens in which a plurality of protruding lens portions are concentrically, continuously formed,

wherein a lens surface and a non-lens surface are formed in each of the lens portions,

the non-lens surface includes a rise surface and a coupling surface,

the rise surface is a surface along an optical axis of the Fresnel lens,

the coupling surface is a surface which is formed on a top portion of each of the lens portions so as to couple the lens surface of the lens portion and the rise surface of the lens portion to each other, and which has a width extending in a radial direction of the Fresnel lens, and

a light absorbing portion is provided in a position along the optical axis of the Fresnel lens which passes through the coupling surface.

2. The Fresnel lens according to claim 1, wherein the light absorbing portion is formed on the coupling surface.

3. The Fresnel lens according to claim 2, wherein the coupling surface is a flat surface vertical to the optical axis of the Fresnel lens.

4. The Fresnel lens according to claim 1, wherein the light absorbing portion is formed in an inside of each of the lens portions.

5. A method of manufacturing a Fresnel lens, comprising:

forming a main body portion in which a plurality of protruding lens portions are concentrically, continuously formed;

covering a surface of each of the lens portions with a mask;

exposing a top portion of each of the lens portions from the mask;

forming a light absorbing portion on the mask and the exposed top portion; and

removing the mask while leaving the light absorbing portion formed on the top portion.

6. The method of manufacturing a Fresnel lens according to claim 5, wherein in the exposing the top portion, the top portion having a curved shape is flattened by polishing the mask and the top portion.

7. A method of manufacturing a Fresnel lens in which a plurality of protruding lens portions are concentrically, continuously formed, the manufacturing method comprising:

arranging a light absorbing material concentrically on a transparent base;

covering the material with a transparent material; and

molding the transparent material into each of the lens portions,

wherein in the molding, the transparent material is molded into the lens portion in such a way that the material is arranged in a position along an optical axis of the Fresnel lens which passes through a top portion of the lens portion.