| 摘要 |
PURPOSE:To ensure an easy setting for a desired exposure value and thus enhance the operatability, by altering a set value by pushing consecutively a selection switch of exposure value while looking at the numerical indication of the exposure value. CONSTITUTION:The input/output interface 5 includes the input and output ports A and B of 8 bits each, and the 2 bits of the port A are used for input of the ON signal for both the lighter and darker switches 7 and 8 for selection of the exposure value. With ON of the switch 7 or 8, the exposure value is increased or decreased by a step. According to this, the segment control signal of the digital display unit 9 that is delivered to the port B varies, and then the display of figures is increase or dectreased by 1. With a consecutive push of the switch 7, the value is increased by a step with every prescribed time of the timer. At the same time, the display of the unit 9 is also increased by 1 and then has no change when the value reaches the upper limit. When the switch 8 is pushed consecutively, at subtraction is given in an exactly same way as the above-mentioned operation of increment. In such way, the set exposure value is easily changed to a desired value with a one-touch operation of the switch. |
