| 摘要 |
PURPOSE:To attain the operation of a sum logarithm of the antilogarithm of plural logarithm information from these information, by combining a subtractor circuit, a data conversion circuit for logarithm area and an adder circuit to constitute an arithmetic circuit of logarithm information. CONSTITUTION:The value measured by a photometry circuit 8 is supplied to a CPU1 after A/D conversion through an A/D conversion circuit 12. When the apex value is obtained for all hitherto photometric quantities, the value N or M is obtained through subtraction between the apex value of the photometric quantity of this time only and that of the hitherto all photometric quantities. Then the value corresponding to log2(1+2**N) or log2(1+**M) is obtained and added to the larger one of both said apex values. |
