ND filter and aperture device using the same
AssigneeCanon Denshi Kabushiki Kaisha
InventorsMichio Yanagi, Yoshio Kawakami, Hitoshi Nozue
Life of this patent
Estimating the term…
Abstract
A plurality of darkness distributions having a predetermined relationship with a darkness distribution for ND-filtering transmission light at the position of an aperture blade in an aperture device are formed on an original. The original is photographed on a film by a camera, and after the film is developed, the film is molded to obtain a plurality of ND filters.
Claims38
An aperture device having a ND filter being attached to a moveable member for adjusting a light amount, said ND filter being formed to have different transmission rates depending on regions,
- said ND filter being formed from a developed film on which an original having a reflection darkness distribution having a predetermined relationship with said different transmission rates has been photographed by a camera, said film comprising a base having a transmission rate of not less than 80%, and an anti-halation layer, wherein said ND filter movably interlocks with a movable aperture member.
An aperture device having a ND filter being attached to a moveable member for adjusting a light amount, said ND filter comprising:
- an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- and
- a diazo film exposed with an ultraviolet ray representing said darkness distribution of said original,
- wherein said diazo film is developed and said developed film is cut in a form of a plurality of ND filters having the same density distribution.
An aperture device in which a ND filter is attached to an aperture blade,
- said ND filter being arranged by a method comprising the steps of:
- preparing an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- exposing a film with light representing said darkness distribution of said original;
- developing said exposed film;
- and
- cutting said developed film in a form of said ND filter, said cutting step including the step of obtaining a plurality of said ND filters having the same density distribution,
- wherein a width of said ND filter is decreased in a direction in which a darkness is increased.
An aperture device in which a ND filter is attached to an aperture blade,
- said ND filter being arranged by a method comprising the steps of:
- preparing an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- exposing a film with light representing said darkness distribution of said original;
- developing said exposed film;
- and
- cutting said developed film in a form of said ND filter, said cutting step including the step of obtaining a plurality of said ND filters having the same density distribution,
- wherein said darkness distribution is formed so that a transmission rate of said ND filter changes stepwise.
An aperture device in which a ND filter is attached to an aperture blade,
- said ND filter being arranged by a method comprising the steps of:
- preparing an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- exposing a film with light representing said darkness distribution of said original;
- developing said exposed film;
- and
- cutting said developed film in a form of said ND filter, said cutting step including the step of obtaining a plurality of said ND filters having the same density distribution,
- wherein said darkness distribution is formed so that a transmission rate of said ND filter changes gradually.
An aperture device in which a ND filter is attached to an aperture blade,
- said ND filter being arranged by a method comprising the steps of:
- preparing an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- photographing said original by a camera to expose micro-copy film;
- developing said exposed film;
- and
- cutting said developed film in a form of said ND filter,
- wherein a width of said ND filter is decreased in a direction in which a darkness is increased.
An aperture device in which a ND filter is attached to an aperture blade,
- said ND filter being arranged by a method comprising the steps of:
- preparing an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- photographing said original by a camera to expose a micro-copy film;
- developing said exposed film;
- and
- cutting said developed film in a form of said ND filter,
- wherein a plurality of lines of darkness distribution regions are formed on said original, a plurality of lines of darkness distribution regions are also formed on said developed film, and a large number of ND filters are obtained by cutting said film in units of lines of said plurality of lines of darkness distribution regions.
An aperture device in which a ND filter is attached to an aperture blade,
- said ND filter being arranged by a method comprising the steps of:
- preparing an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- photographing said original by a camera to expose a micro-copy film;
- developing said exposed film;
- and
- cutting said developed film in a form of said ND filter,
- wherein said darkness distribution is formed, so that a transmission rate of said ND filter changes stepwise.
An aperture device in which a ND filter is attached to an aperture blade,
- said ND filter being arranged by a method comprising the steps of:
- preparing an original having a darkness distribution having a predetermined relationship with a darkness distribution for providing a ND filtering function;
- photographing said original by a camera to expose a micro-copy film;
- developing said exposed film;
- and
- cutting said developed film in a form of said ND filter,
- wherein said darkness distribution is formed, so that a transmission rate of said ND filter changes gradually.
Dependencies are inferred from the claim text.