| 摘要 |
PROBLEM TO BE SOLVED: To make a call registration effective time clear by changing the flashing period of a call registration indicator lamp according to a call registration remaining time. SOLUTION: First, this controller decides if a call registration is made effective or not and, if the call registration is made effective, it makes the registration of a call button 21 effective and starts a timer for a call registration effective time. Next, it subtracts the present value of the timer from a call registration effective predetermined time to calculate a remaining call registration effective time T. If the remaining time T becomes zero or negative, a call registration by the call button 21 is made ineffective. If the remaining time T is positive, the flashing period TF of an indicator lamp 23 for indicating the effective call registration is calculated by an equation of TF=K×T (where K is a predetermined constant). As the remaining call registration effective time becomes shorter, the flashing period of the indicator lamp 23 becomes shorter, which can indicate that the registration effective time becomes shorter. |
