×

Buzzer output control device and buzzer output control method

  • US 9,583,089 B2
  • Filed: 09/17/2013
  • Issued: 02/28/2017
  • Est. Priority Date: 12/26/2012
  • Status: Active Grant
First Claim
Patent Images

1. A buzzer output control apparatus comprising:

  • a buzzer for outputting a sound having a pitch corresponding to a frequency of a buzzer driving signal being input and volume corresponding to a duty ratio of the buzzer driving signal;

    an inaudible frequency signal generation unit for generating an inaudible frequency pulse signal having a predetermined inaudible frequency;

    an audio frequency signal generation unit for generating an audio frequency pulse signal having a predetermined audio frequency lower than the inaudible frequency;

    a signal synthesizing unit for synthesizing the inaudible frequency pulse signal and the audio frequency pulse signal and thus generating a synthesized frequency pulse signal having the inaudible frequency pulse signal in an ON time of the audio frequency pulse signal;

    a first duty ratio setting unit for generating a buzzer driving signal set to gradually increase a duty ratio of the inaudible frequency pulse signal in the synthesized frequency pulse signal over a first predetermined period of the synthesized frequency pulse signal; and

    a buzzer driving unit for sounding the buzzer on the buzzer driving signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×