发明名称 |
Exposure control device for a camera |
摘要 |
An exposure control device is disclosed which has an extremely high accuracy as compared with the prior art, the error range being within a one-eighth step. For such a highly accurate control of exposure time, a value of exposure time to be determined is converted to a binary code of n bits, of which the lowest one bit is weighed one-eighth step. Based on the decimal number corresponding to the upper m bits of the binary code, the frequency of the control signal is adjusted and is used in reading out the lower (n - m) bits of the same binary code, whereby the period of actuation of the shutter is determined.
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申请公布号 |
US4037233(A) |
申请公布日期 |
1977.07.19 |
申请号 |
US19750606572 |
申请日期 |
1975.08.21 |
申请人 |
CANON KABUSHIKI KAISHA |
发明人 |
SHINODA, NOBUHIKO;ITO, TADASHI;ITO, FUMIO;MASHIMO, YUKIO;SAKURADA, NOBUAKI |
分类号 |
G03B7/091;G03B7/093;(IPC1-7):G03B7/08 |
主分类号 |
G03B7/091 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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