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Image pickup apparatus

  • US 6,771,315 B1
  • Filed: 07/21/1999
  • Issued: 08/03/2004
  • Est. Priority Date: 07/31/1998
  • Status: Expired due to Fees
First Claim
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1. An image pickup apparatus comprising an exposure control mechanism for adjusting a quantity of light flux entering a shooting lens system, said exposure control mechanism comprising:

  • a diaphragm made up of diaphragm blades movable in a plane perpendicular to an optical axis in opposite directions to define a diaphragm aperture; and

    an ND filter formed by placing a plurality of filter plates in adjacently overlapped relation, said filter plates having the same transmittance but being different in size, wherein when said diaphragm blades are displaced from an aperture open state in a direction to restrict the quantity of the light flux, an aperture area is restricted by said diaphragm blades from the open state to a predetermined aperture area, and thereafter said ND filter is advanced into said diaphragm aperture successively from a combination of said ND filter elements having the highest transmittance while the predetermined aperture area is maintained.

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