| 摘要 |
<P>PROBLEM TO BE SOLVED: To transmit a plurality of kinds of transmission signals whose signal levels are different among adjoining sensor units. <P>SOLUTION: Each sensor unit is formed by connecting a projector unit 3, a light-receiving unit 4, a reception unit 9, a transmitting unit 10, etc. to a control circuit 2. The reception unit 9 receives light from an adjoining unit by a light receiving element 13, causes the received signal to pass through an amplifier circuit 16 etc. and compares it with a comparator circuit 17, and detects it as data by a received data processing circuit 18. The protocol of a transmission signal corresponding to the number of pulses counted by a pulse counting circuit 20 is determined by a receiving protocol determination circuit 21, and the comparison level of the comparator circuit 17 is set to a corresponding threshold level. Consequently, transmission signals can be received even when their signal levels differ. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
