| 摘要 |
PROBLEM TO BE SOLVED: To provide an image pickup device in which mixing-in of a sound generated by the rotation of a cooling fan is reduced.SOLUTION: The image pickup device is provided with frequency axis conversion means for converting a sound into data having a per-frequency amplitude, time axis conversion means for converting the data having a per-frequency amplitude into data having a per-time amplitude, and a recording unit. A calculation formula is created in which the per-frequency amplitude of a rotation sound of a cooling fan is calculated for a plurality of revolution speeds, and the revolution speed of the cooling fan is made to be a variable for each harmonic wave by linear interpolation or secondary interpolation from data of harmonics amplitude from the primary to the n'th order of the fundamental frequency for each of the plurality of revolution speeds. The calculation formula is recorded in the recording unit. The revolution speed of the cooling fan rotating with a revolution speed corresponding to the internal temperature of an apparatus is detected; the amplitude of the rotation sound of the cooling fan is calculated, on the basis of the calculation formula, for each harmonic wave from the detected revolution speed; an amplitude for each harmonic wave calculated from a sound inputted by sound input means is subtracted; and the subtracted sound is encoded by per-time amplitude or compression before being outputted. |
