| US 7,567,286 B2 | ||
| Image pickup apparatus | ||
| Hirofumi Takei, Yokohama (Japan); Naoya Kaneda, Chigasaki (Japan); and Tadanori Okada, Utsunomiya (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Nov. 13, 2006, as Appl. No. 11/558,975. | ||
| Application 11/558975 is a division of application No. 09/240635, filed on Jan. 29, 1999, abandoned. | ||
| Claims priority of application No. 10-020938 (JP), filed on Feb. 02, 1998; application No. 10-119913 (JP), filed on Apr. 15, 1998; application No. 10-179950 (JP), filed on Jun. 26, 1998; and application No. 11-013527 (JP), filed on Jan. 21, 1999. | ||
| Prior Publication US 2007/0065135 A1, Mar. 22, 2007 | ||
| Int. Cl. H04N 5/225 (2006.01) | ||
| U.S. Cl. 348—335 [348/340] | 4 Claims |

| 1. An image pickup apparatus comprising:
diaphragm means for varying a size of a diaphragm aperture which determines a light quantity to be made incident on image
pickup means;
a light-attenuating filter which is capable of moving between an insertion position at which said light-attenuating filter
covers the whole of the diaphragm aperture and a retraction position at which said light-attenuating filter is retracted from
the whole of the diaphragm aperture; and
control means for both controlling said diaphragm means and controlling an image pickup time of said image pickup means and
a movement of said light-attenuating filter, according to a subject illuminance detected through said image pickup means,
wherein when the size of the diaphragm aperture reaches a first predetermined value with said light-attenuating filter being
positioned at the retraction position and: (i) an exposure time being a predetermined high-speed shutter time, said control
means executes control which moves said light-attenuating filter to the insertion position and, at the same time, makes the
exposure time longer than the predetermined high-speed shutter time; or (ii) the exposure time being longer than the predetermined
high-speed shutter time, said control means executes control which, as the subject illuminance becomes higher, makes the exposure
time shorter toward the predetermined high-speed shutter time while maintaining the size of the diaphragm aperture at the
first predetermined value; and
wherein when the size of the diaphragm aperture reaches a second predetermined value larger than the first predetermined value
with said light-attenuating filter being positioned at the insertion position and the exposure time being a predetermined
low-speed shutter time, said control means executes control which moves said light-attenuating filter to the retraction position
and, at the same time, makes the exposure time shorter than the predetermined low-speed shutter time.
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