INCOMING CALL NOTICE DEVICE FOR PORTABLE TELEPHONE

• Main Authors: HARADA HIROYUKI, UTSUNO KAZUMOTO, MASUDA HISAHIRO, SAWARA FUMIO
• Format: Patent
• Language: English
• Published: 26.02.1999
• Edition: 6
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; WIRELESS COMMUNICATIONS NETWORKS

PROBLEM TO BE SOLVED: To prevent erroneous incoming call notice responding to noise by preventing a notice means from operating unless continuation time exceeds reference time even if strong noise exceeding reference voltage is received. SOLUTION: When reference time Tr is adjusted to be slightly shorter than the emitting time of a response radio wave in a portable telephone set, an H level is continuously outputted from a comparator during the emission of the response radio wave and the time is measured in a second judgment means 7. Since the response radio wave is in the middle of emission even if measuring time is matched with reference time Tr, the output of the second judgment means 7 becomes the H level, a vibration source 5 operates and the incoming call is noticed. On the other hand, discharged noise has strong electromagnetic energy and has the frequency component of a wide range. But noise only instantaneously occurs and it is below the emitting time of the response radio wave of the rortable telephone set. Even if it becomes to be output voltage Vs > refrence voltage Vr in a detection circuit, the output of the second judgement means 7 does not become the H level and the vibration source 5 does not operate.