Title:
AUTOMATIC ILLUMINANCE CONTROL METHOD AND DEVICE
Document Type and Number:
Japanese Patent JP3431721
Kind Code:
B2
Abstract:
PURPOSE: To provide an automatic illuminance control method and device by which the illuminance of a photographic sensitometer can be automatically controlled at a high speed to an arbitrary target illuminance.
CONSTITUTION: When a target illuminance value is input into a CPU 18, a table memory 21 is reffered to and the rays conforming to the target illuminance value are selected through optical filters F0 to F3, and they are inserted into the optical path. The illuminance is measured by an illumination meter 16, and the displacement quantity of a ND filter 3 for achieving the target illuminance value is calculated from this measured value and from the relationship between the displacement quantity of the ND filter 3 and the intensity of illumination. On the basis of this calculated result, a motor 11 is driven and the ND filter 3 is inserted into the optical route. The illuminance is measured, and the displacement quantity of ND filter 3, the drive of the motor 11, and the measurement are repeated until the measured illuminance value is brought into within a prescribed error.
Inventors:
Yoshio Kawakami
Takehiko Miyoshi
Takehiko Miyoshi
Application Number:
JP9387295A
Publication Date:
July 28, 2003
Filing Date:
April 19, 1995
Export Citation:
Assignee:
Fuji Photo Film Co., Ltd.
International Classes:
G01J3/50; G01J1/02; (IPC1-7): G01J3/50; G01J1/02
Domestic Patent References:
| JP620924A | ||||
| JP5814139U |
Attorney, Agent or Firm:
Kazunori Kobayashi
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