Shutter/diaphragm apparatus

• US 5,997,187 A
• Filed: 09/08/1997
• Issued: 12/07/1999
• Est. Priority Date: 09/10/1996
• Status: Expired due to Fees

• Current Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Original Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Inventors: Hamasaki, Takuji
• Primary Examiner(s): Mathews, A. A.
• Application Number:
  US08/925,144
• Time in Patent Office: 820 Days
• Field of Search: 396/449, 396/451, 396/458, 396/460, 396/493, 396/494, 396/497, 396/505, 396/510
• US Class Current: 396/449
• CPC Class Codes: G03B 9/24 Adjusting size of aperture formed by members when fully open so as to constitute a virtual diaphragm that is adjustable

Abstract

A shutter/diaphragm apparatus includes an intermediate plate between a diaphragm cam plate and a diaphragm rotating plate. A plurality of blades are provided between the diaphragm cam plate and the intermediate plate and between the diaphragm rotating plate and the intermediate plate. The blades are driven by a relative rotation between the diaphragm cam plate and the diaphragm rotating plate to vary the size of an aperture defined by the blades. The relative rotation can also completely close the aperture. The invention can also be applied to a diaphragm apparatus which has no shutter function.

Claims

1. A shutter/diaphragm apparatus, comprising:

a diaphragm cam plate which is provided with cam grooves and a center opening;

a diaphragm rotating plate which is provided with engaging holes and a center opening, said diaphragm rotating plate being rotatable relative to said diaphragm cam plate;

an intermediate plate which is provided with relief grooves corresponding to said cam grooves of said diaphragm cam plate, and with relief holes corresponding to said engaging holes of said diaphragm rotating plate, and with a center opening; and

a plurality of shutter/diaphragm blades to define a selected size of an aperture within said center openings of said diaphragm cam plate, said diaphragm rotating plate and said intermediate plate, and to close said center openings of said diaphragm cam plate, said diaphragm rotating plate and said intermediate plate, each of said plurality of blades being provided with a pivot shaft and an operation shaft, said plurality of blades being separated into two groups, a first group positioned between said diaphragm cam plate and said intermediate plate, and a second group positioned between said intermediate plate and said diaphragm rotating plate,

wherein said operation shafts of said blades of said first group are inserted into said cam grooves of said diaphragm cam plate, and said pivot shafts of said blades of said first group are inserted into said relief holes of said intermediate plate and said engaging holes of said diaphragm rotating plate,

and further wherein said operation shafts of said blades of said second group are inserted into said relief grooves of said intermediate plate and said cam grooves of said diaphragm cam plate, and said pivot shafts of said blades of said second group are inserted into said engaging holes of said diaphragm rotating plate.

2. A shutter/diaphragm apparatus according to claim 1, wherein said diaphragm cam plate is held so as not to rotate, and said diaphragm rotating plate is rotatably supported, so that said diaphragm rotating plate can be rotated to move said blades.

3. A shutter/diaphragm apparatus according to claim 2, wherein said diaphragm rotating plate is provided on an outer peripheral surface thereof with a gear which is adapted to rotate said diaphragm rotating plate.

4. A shutter/diaphragm apparatus according to claim 1, wherein each of said blades is provided with a base portion and a front end portion extending from said base portion, said pivot shafts and said operation shafts being provided on said base portions, each of said blades being provided with a curved edge portion between said base portion and said front end portion, said aperture being defined by said curved edge portions of said blades.

5. A shutter/diaphragm apparatus according to claim 1, wherein said blades in each of said first and second groups are spaced at an equi-angular distance in a circumferential direction of said diaphragm cam plate and said diaphragm rotating plate.

6. A shutter/diaphragm apparatus according to claim 5, wherein said blades of said first group are spaced at said equi-angular distance in said circumferential direction of said diaphragm cam plate, and said blades of said second group are spaced at said equi-angular distance in said circumferential direction of said diaphragm rotating plate, respectively.

7. A shutter/diaphragm apparatus according to claim 1, wherein said blades are identical in shape.

8. A shutter/diaphragm apparatus according to claim 1, wherein the number of said blades of said first group is the same as the number of said blades of said second group.

9. A shutter/diaphragm apparatus according to claim 1, wherein said diaphragm cam plate, said intermediate plate and said diaphragm rotating plate are arranged such that the axes of said center openings thereof are aligned on an optical axis of a photographing system of a camera to which said shutter/diaphragm apparatus is applied.

10. A shutter/diaphragm apparatus, comprising:

an intermediate plate provided between a diaphragm cam plate and a diaphragm rotating plate, one of the diaphragm cam plate and the diaphragm rotating plate being rotated, the intermediate plate being rotated together with the rotated one of the diaphragm cam plate and the diaphragm rotating plate; and

a plurality of blades provided between said diaphragm cam plate and said intermediate plate, and between said diaphragm rotating plate and said intermediate plate,

wherein said blades are rotated by a relative rotation between said diaphragm cam plate and said diaphragm rotating plate to control a size of an aperture defined by said blades and to completely close said aperture.

11. A shutter/diaphragm apparatus, comprising:

a diaphragm cam plate and a diaphragm rotating plate, one of the diaphragm cam plate and the diaphragm rotating plate being rotated, shutter/diaphragm blades positioned between the diaphragm cam plate and the diaphragm rotating plate so that a size of an aperture defined by said blades is varied and said aperture is completely closed by a relative rotation between said diaphragm cam plate and said diaphragm rotating plate; and

an intermediate plate which is positioned between said diaphragm cam plate and said diaphragm rotating plate, the intermediate plate being rotated together with the one of the diaphragm cam plate and the diaphragm rotating plate that is rotated, said intermediate plate being arranged to divide said shutter/diaphragm blades into two groups, a first group positioned between said diaphragm cam plate and said intermediate plate, and a second group positioned between said intermediate plate and said diaphragm rotating plate.

12. A diaphragm apparatus comprising:

an intermediate plate provided between a diaphragm cam plate and a diaphragm rotating plate, one of the diaphragm cam plate and the diaphragm rotating plate being rotated, the intermediate plate being rotated together with one of the diaphragm cam plate and the diaphragm rotating plate that is rotated; and

a plurality of blades provided between said diaphragm cam plate and said intermediate plate, and between said diaphragm plate and said intermediate plate,

wherein said blades are rotated by a relative rotation between said diaphragm cam plate and said diaphragm rotating plate to control a size of an aperture defined by said blades.

13. A diaphragm apparatus comprising:

a diaphragm cam plate which is provided with cam grooves and a center opening;

a diaphragm rotating plate which is provided with engaging holes and a center opening, said diaphragm rotating plate being rotatable relative to said diaphragm cam plate;

an intermediate plate which is provided with relief grooves corresponding to said cam grooves of said diaphragm cam plate, and with relief holes corresponding to said engaging holes of said diaphragm rotating plate, and with a center opening; and

a plurality of diaphragm blades to define a selected size of an aperture within said center openings of said diaphragm cam plate, said diaphragm rotating plate and said intermediate plate, each of said plurality of blades being provided with a pivot shaft and an operation shaft, said plurality of blades being separated into two groups, a first group positioned between said diaphragm cam plate and said intermediate plate, and a second group positioned between said intermediate plate and said diaphragm rotating plate,

wherein said operation shafts of said blades of said first group are inserted into said cam grooves of said diaphragm cam plate, and said pivot shafts of said blades of said first group are inserted into said relief holes of said intermediate plate and said engaging holes of said diaphragm rotating plate,

and further wherein said operation shafts of said blades of said second group are inserted into said relief grooves of said intermediate plate and said cam grooves of said diaphragm cam plate, and said pivot shafts of said blades of said second group are inserted into said engaging holes of said diaphragm rotating plate.

14. A diaphragm apparatus comprising:

a diaphragm cam plate and a diaphragm rotating plate, one of the diaphragm cam plate and the diaphragm rotating plate being rotated, diaphragm blades positioned between the diaphragm cam plate and the diaphragm rotating plate so that a size of an aperture defined by said diaphragm blades is varied by a relative rotation between said diaphragm cam plate and said diaphragm rotating plate; and

an intermediate plate which is positioned between said diaphragm cam plate and said diaphragm rotating plate, the intermediate plate being rotated together with the rotated one of the diaphragm cam plate and the diaphragm rotating plate, said intermediate plate being positioned to divide said diaphragm blades into two groups, a first group positioned between said diaphragm cam plate and said intermediate plate, and a second group positioned between said intermediate plate and said diaphragm rotating plate.