| 摘要 |
PROBLEM TO BE SOLVED: To provide a convenient finish detection system.SOLUTION: A finish detection system 3 comprises: a transmitter 10 comprising a light emitting element for transmitting a light pulse from one end of a goal line, a built-in battery for supplying a power source to the light emitting element, a voltage determination circuit for determining whether or not voltage of the built-in battery is equal to or lower than reference voltage, and an oscillation control circuit for modulating the light pulse transmitted by the light emitting element when it is determined that the voltage of the built-in battery is equal to or lower than the reference voltage; and a receiver 20 comprising a light receiving element for receiving the light pulse at the another end of the goal line, and a microcomputer for determining whether or not the light receiving element receives no light pulse for a predetermined period. The microcomputer reports that a ski player has finished when determining that the light receiving element receives no light pulse for the predetermined period. The microcomputer detects modulation of the light pulse received by the light emitting element. The microcomputer reports reduction in a residual amount of the built-in battery when detecting the modulation of the light pulse. |
