Abstract A filter holder for holding a gelatin filter in front of a photographic lens consists of a filter ring having a threaded portion for attaching the lens barrel, a filter mounting device relatively rotatable with respect to the ring and spring means interposed between the filter ring and the filter mounting device. Between the spring means and the filter ring there is provided means for rotating the holder together with the ring to mount them on the lens barrel, and at the final stage against the spring action of the spring means only the filter mounting device rotates while the ring is kept stationary so as to adjust the location of the filter mounting at a position suitable for changing the filter or for phototaking. However, when the filter holder is removed from the lens barrel, said means acts to rotate the ring together with the filter mounting device so as to secure the removal of the filter holder from the lens barrel.
A filter holder for attaching a filter to a lens barrel, comprising a member having a threaded portion for threading engagement with a threaded portion of said lens barrel: means having a portion for receiving said filter: and a transmission mechanism interposed between said member and said means for selectively transmitting rotation of said means to said member to threadingly engage said member with said lens barrel, said transmission mechanism being arranged to frictionally transmit the rotation in one direction of said means which causes the threading engagement of said member with said lens barrel to said member until said threading engagement is completed, to prevent said transmission after completion of said engagement to thereby permit said means to rotate relative to said member, and to lock said member and said means to positively transmit the reverse rotation of said means which causes disengagement of said member from said barrel.
Claim 2
Dependent Claim
150 words
A filter holder for attaching a filter to a lens barrel, comprising a member having a threaded portion for threading engagement with a threaded portion of said lens barrel: means having a portion for receiving said filter: and a transmission mechanism interposed between said member and said means for selectively transmitting rotation of said means to said member to threadingly engage said member with said lens barrel, said transmission mechanism being arranged to frictionally transmit the rotation in one direction of said means which causes the threading engagement of said member with said lens barrel to said member until said threading engagement is completed, to prevent said transmission after completion of said engagement to thereby permit said means to rotate relative to said member, and to lock said member and said means to positively transmit the reverse rotation of said means which causes disengagement of said member from said barrel.
Claim 3
Dependent Claim
48 words
A filter holder according to claim 1, wherein said transmission mechanism includes notches provided on one of said means and said member, a projection provided on the other one of said means and said member, and biasing means for biasing said projection to engage one of said notches.
Claim 4
Dependent Claim
46 words
A filter holder according to claim 1, wherein said projection engages said notches by means of said biasing means during said transmission, and said projection is disengaged from said notches against said biasing means after completion of said engagement of said member with said lens barrel.
Claim 5
Dependent Claim
17 words
A filter holder according to claim 3, wherein said projection is in the shape of a quarter-sphere.