| 摘要 |
PURPOSE:To attain optimum focusing operation everytime by changing a adjusting speed of focusing in accordance with contrast. CONSTITUTION:The contrast level of a subject is appreciated and an AF motor driving speed corresponding to the appreciation is set up. When the contrast of the subject is low, a contrast deciding part 113 outputs a signal 114 for specifying the low speed driving of the AF motor on the basis of a contrast appreciating value signal 112 outputted from an arithmetic part 104, so that a lens group 10 is not moved to a false position until a shifted distance outputted from the arithmetic part 104 always shows a false fixed value, i.e. an incorrect range finding in one direction is frequently generated. On the other hand, the contrast deciding part 113 outputs a signal 114 for specifying a normal driving speed in accordance with the increase of the contrast and a comparison deciding part 118 increases its response capacity. Consequently, a motor driving circuit 110 repeats stable focusing operation on the basis of distance information, i.e. a shifted distance signal 105. |
