| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make an alarm sound that can efficiently notify that a door is left opened regardless of a user. <P>SOLUTION: An alarm device 4 which outputs sound of a first frequency, and outputs another sound of a frequency different from the first frequency is configured to give an alarm with the sound of the first frequency when recognizing that the door 101 has been left opened for a predetermined period of time based on information from a door opening detector 102, and then give an alarm with the sound of the frequency different form the first frequency after a predetermined period of time from the beginning of the alarm with the sound of the first frequency. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
