Communication terminal device

A communication terminal device capable of being connected with an external telephone and of receiving and transmitting facsimile data from and to a network, comprising:

• an off-hook detector configured to detect an off-hook condition of the external telephone,
• a semiconductor DAA (Digital Access Arrangement) including an impedance switcher configured to switch impedances and a direct-current resistance switcher configured to switch direct-current resistances;
• an impedance switching controller configured to instruct the impedance switcher to switch the impedances;
• a direct-current resistance switching controller configured to instruct the direct-current resistance switcher to switch the direct-current resistances,
• wherein, when the off-hook detector detects the off-hook condition of the external telephone, the impedance switching controller instructs the impedance switcher to switch the impedances and the direct-current resistance switching controller instructs the direct-current resistance switcher to switch the direct-current resistances,
• wherein
• the impedance switcher is capable of selecting at least one of a first impedance and a second impedance that is higher than the first impedance,
• the direct-current resistance switcher is capable of selecting at least one of a first direct-current resistance and a second direct-current resistance that is higher than the first direct-current resistance,
• the impedance switching controller instructs the impedance switcher to select the second impedance upon detection of the off-hook condition of the external telephone and instructs the impedance switcher to select the first impedance upon a facsimile data reception,
• the direct-current resistance switching controller instructs the direct-current resistance switcher to select the second direct-current resistance upon detection of the off-hook condition of the external telephone and instructs the direct-current resistance switcher to select the first direct-current resistance, upon a facsimile data reception.

A communication terminal device capable of being connected with an external telephone and of receiving and transmitting facsimile data from and to a network, comprising:

• a network voltage detector configured to detect a network voltage;
• an off-hook determiner configured to determine whether or not the external telephone is off-hook by comparing the detected network voltage detected by the network voltage detector with a reference voltage;
• a semiconductor DAA (Data Access Arrangement) including an impedance switcher to switch impedances and a direct-current resistance switcher to switch direct-current resistances;
• an impedance switching controller configured to instruct the impedance switcher to switch the impedances;
• a direct-current resistance switching controller configured to instruct the direct-current resistance switcher to switch the direct-current resistances,
• wherein, when the off-hook determiner determines that the external telephone is off-hook, the impedance switching controller instructs the impedance switcher to switch the impedances and the direct-current resistance switching controller instructs the direct-current resistance switcher to switch the direct-current resistances,
• wherein
• the impedance switcher is capable of selecting at least one of a first impedance and a second impedance that is higher than the first impedance,
• the direct-current resistance switcher is capable of selecting at least one of a first direct-current resistance and a second direct-current resistance that is higher than the first direct-current resistance,
• the impedance switching controller instructs the impedance switcher to select the second impedance upon detection of the external telephone being off-hook and instructs the impedance switcher to select the first impedance, upon a facsimile data reception,
• the direct-current resistance switching controller instructs the direct-current resistance switcher to select the second direct-current resistance upon detection of the external telephone being off-hook and instructs the direct-current resistance switcher to select the first direct-current resistance, upon a facsimile data reception.