Title:
COMMUNICATION EQUIPMENT
Document Type and Number:
Japanese Patent JP2014127833
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To suppress, even when a capacitance element is connected between line connection terminals to which a telephone line is connected, the erroneous detection of the presence/absence of telephone line connection due to the capacitance element, and to detect the absence/presence of the telephone line connection with high accuracy.SOLUTION: A CPU 6 determines whether or not a line voltage is equal to or more than a first voltage threshold (for example, 2V) in a line open state. When the line voltage is equal to or more than the first voltage threshold, there is possibility that a telephone line 51 is connected to a line side jack 10, and there is possibility that although the telephone line 51 is not connected, it is determined that the line voltage is equal to or more than the first voltage threshold due to the accumulation of electric charge in a capacitor C1. Then, the CPU 6 allows a line opening/closing switch 13 to turn on for closing the line, and checks the line voltage again in the line closed state. Then, when the line voltage is equal to or more than a second voltage threshold (for example, 2V), it is determined that the telephone line 51 is connected to a line side jack 10.
Inventors:
MORI TAKAHITO
Application Number:
JP2012282831A
Publication Date:
July 07, 2014
Filing Date:
December 26, 2012
Export Citation:
Assignee:
BROTHER IND LTD
International Classes:
H04M1/738; H04N1/32
Domestic Patent References:
| JP2012129918A | 2012-07-05 | |||
| JP2011071883A | 2011-04-07 | |||
| JP2009130524A | 2009-06-11 | |||
| JP2006014134A | 2006-01-12 |
Attorney, Agent or Firm:
Nagoya International Patent Service Corporation