Optical lens, lens unit, imaging module, electronic device, optical lens production method, lens mold, and shape correction method for lens mold

Patent metadata

Field	Value
Publication number	US-9703017-B2
Application number	US-201514843949-A
Country	US
Kind code	B2
Filing date	Sep 2, 2015
Priority date	Mar 27, 2013
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

An optical lens 11 , which has a lens section with a refractive power, has concave marks 33, 35, 37 , and 39 which are formed to be recessed on a surface of the lens section, in an effective optical lens surface which contributes to image forming of the lens section. A width of each of these concave marks 33, 35, 37 , and 39 is equal to or greater than 0.05 μm and equal to or less than 14 μm, and a depth of recession of each concave mark is equal to or greater than 0.05 μm and equal to or less than 5 μm.

First claim

What is claimed is:

1. An optical lens comprising a lens section with a refractive power, wherein the lens section comprises one or more effective optical lens surfaces which contributes to image forming of the lens section, and a plurality of smoothly curved first concave marks and a smoothly curved second concave mark, which are formed to be recessed on one or more surfaces of the lens section, are provided in the one or more effective optical lens surfaces, wherein a width of each of the first and second concave marks is equal to or greater than 0.05 μm and equal to or less than 14 μm, wherein a depth of recession of each of the first and second concave marks is equal to or greater than 0.05 μm and equal to or less than 5 μm, and wherein at least one of the first concave marks is formed along a simple closed curve that encloses the optical axis of the lens section, and the second concave mark is formed on the optical axis.

2. The optical lens according to claim 1 , wherein a ratio of a total area of the first and second concave marks within the effective optical lens surface of the lens section to an area of the effective optical lens surface is equal to or less than 1.2%.

3. The optical lens according to claim 1 , wherein each of the first concave marks is formed along a curved line with all points on the curved line equidistant from an optical axis of the lens section when the optical axis is set as a center of the curved lines.

4. The optical lens according to claim 1 , wherein the first concave marks are formed spaced apart from each other along a circumference of a circle centered on the optical axis.

5. The optical lens according to claim 4 , wherein the first concave marks are spaced apart equidistantly with respect to each other along a circumference of a circle centered on the optical axis.

6. The optical lens according to claim 1 , wherein the lens section is an aspheric lens.

7. The optical lens according to claim 1 , wherein the lens section is a meniscus lens, and wherein at least one of the first and second concave marks is located on a first lens surface of the lens section, and at least another one of the first and second concave marks is located on a second lens surface of the lens section.

8. A lens unit, wherein at least one or more of the optical lenses according to claim 1 are held by a lens holder.

9. An imaging module comprising: the lens unit according to claim 8 ; and an imaging section that captures an image of a subject through the lens unit.

10. An electronic device, wherein the imaging module according to claim 9 is mounted.

11. The electronic device according to claim 10 , wherein the electronic device is an on-board camera.

12. The electronic device according to claim 10 , wherein the electronic device is a digital camera.

13. An optical lens production method for molding an optical lens according to claim 1 by using a lens mold with a transcriptional surface having a lens shape, wherein the lens mold has a convex transcriptional section which is formed to protrude from the transcriptional surface having the lens shape toward the outside, wherein an optical lens surface of the optical lens is molded by the transcriptional surface, and the first and second concave marks are molded by the convex transcriptional section, wherein a width of each of the first and second concave marks is equal to or greater than 0.05 μm and equal to or less than 14 μm, wherein a depth of recession of each of the first and second concave marks is equal to or greater than 0.05 μm and equal to or less than 5 μm, and at least one of the first concave marks is formed along a simple closed curve that encloses the optical axis of the lens section, and the second concave mark is formed on the optical axis.

14. The lens mold used in the optical lens production method according to claim 13 .

15. A shape correction method for a lens mold, wherein the lens mold comprises a transcriptional surface having a lens shape, wherein the lens mold has a convex transcriptional section which is formed to protrude from the transcriptional surface having the lens shape toward the outside, the method comprising:
molding the optical lens of claim 1 , which has the second concave mark and the plurality of first concave marks, by using the lens mold which is produced on the basis of lens shape design data indicating a prescribed lens surface shape;
acquiring measured surface shape data, which indicates a lens surface shape of the optical lens, by detecting positions of the second concave mark and positions of the plurality of first concave marks of the optical lens which is molded;
acquiring differential data, which is for matching a surface shape of the optical lens with a surface shape based on the lens shape design data, by comparing the measured surface shape data with the lens shape design data; and
producing a lens module on the basis of lens shape correction data which is obtained by correcting the lens shape design data on the basis of the differential data.

Assignees

• Fujifilm Corp

Inventors

• Ito Hidekane
• Matsumoto Nariya

Classifications

• B29D11/00336

  by making depressions in the lens surfaces · CPC title

• B29D11/00471

  made by rotational casting (B29D11/00115 takes precedence) · CPC title

• B29D11/00432

  Auxiliary operations, e.g. machines for filling the moulds (B29D11/00125 takes precedence) · CPC title

• B29K2995/0026

  Transparent · CPC title

• B29D11/00951

  Measuring, controlling or regulating · CPC title