| 摘要 |
PROBLEM TO BE SOLVED: To provide a sight line guiding indicator by which the lighting interval of the guiding indicators can be kept constant with high accuracy. SOLUTION: A sight line guiding indicator as provided with guide indicators 1 being lit at proscribed time intervals, an oscillator for oscillating the reference signal that becomes the reference of lighting interval of the guide indicator 1, a synchronizing signal receiving unit 2 for receiving the synchronizing signal of a constant time period, a counting means for counting the numbers of the reference signals oscillated form the oscillator within the time of a prescribed period of the synchronizing signal that has been received by the synchronizing signal receiving unit 2, and a lighting interval determining means for determining the lightening interval of the guide indicator 1 on the basis of the number of signals of the reference signal counted by the counting means. Even if the frequency of the reference signal being output form the oscillator is changed due to the variation of the environmental temperature or the like, the time corresponding to the signal number of the reference signal counted within a prescribed period of the synchronizing signal is kept constant, so that the time of lighting interval of the guide indicator 1 determined on the basis of this number of the counting signals is set to be constant. |
