US 12,135,463 B2
Apparatus for altering quantum of light passing through a lens of a photographic device
Hitesh Gopal Gwalani, Nagpur (IN)
Assigned to Freewell Industry Company Limited, Hong Kong (HK)
Filed by Freewell Industry Company Limited, Hong Kong (HK)
Filed on Feb. 9, 2023, as Appl. No. 18/166,500.
Application 18/166,500 is a division of application No. 17/145,420, filed on Jan. 11, 2021, granted, now 11,846,824.
Prior Publication US 2023/0194821 A1, Jun. 22, 2023
Int. Cl. G02B 7/00 (2021.01); G02B 5/20 (2006.01); G02B 5/30 (2006.01)
CPC G02B 7/006 (2013.01) [G02B 5/205 (2013.01); G02B 5/3025 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An apparatus for altering quantum of light passing through a lens of a photographic device, the apparatus comprising:
a base assembly configured to be detachably coupled to the lens of the photographic device, wherein:
the base assembly defines:
a first circumferential platform;
a second circumferential platform elevated relative to the first circumferential platform and having a radius larger than that of the first circumferential platform;
a first groove under the first circumferential platform; and
a second groove under the second circumferential platform; and
the base assembly comprises:
a first set of one or more magnets received in the first groove; and
a second set of one or more magnets received in the second groove;
a first assembly, wherein,
the first assembly comprises a first filter and a first base frame;
at least a portion of the first base frame has a ferrous property; and
the first assembly is received over the first circumferential platform, and held over the first circumferential platform by magnetic force from the first set of one or more magnets, wherein at least a portion of the first base having ferrous property is magnetically attracted to the first set of one or more magnets of the base assembly;
a second assembly comprising a second filter and a third set of one or more magnets; and
a third assembly comprising a third filter and a fourth set of one or more magnets;
wherein,
the first assembly is configured to be detachably coupled to the base assembly;
the second assembly is configured to be detachably coupled to the base assembly;
the third assembly is configured to be detachably coupled to the base assembly, wherein,
the second assembly is received over the second circumferential platform and magnetically held over the second circumferential platform by magnetic force between the third set of one or more magnets of the second assembly and the second set of one or more magnets of the base assembly; or
the third assembly is received over the second circumferential platform and magnetically held over the second circumferential platform by magnetic force between the fourth set of one or more magnets of the third assembly and the second set of one or more magnets of the base assembly;
combination of the first filter and the second filter forms a first range of neutral density filter; and
combination of the first filter and the third filter forms a second range of neutral density filter.