Electronic apparatus

1. An electronic apparatus comprising:

a speaker;

a terminal configured to input an audio signal from an external device;

an amplifier configured to amplify the audio signal which is input from the terminal, and to output audio from the speaker;

a power supply circuit configured to supply power to the amplifier from a battery when power is not supplied externally;

a switch configured to switch between a first path by which the amplifier is connected to a sound controller operating when the electronic apparatus is in an operative state and a second path by which the terminal and the amplifier are connected to each other without the sound controller;

a setting module configured to set data which indicates whether audio output from the speaker is to be enabled or disabled;

a first state detector configured to detect a first state where an external terminal for inputting the audio signal is connected to the terminal; and

a controller configured to control the switch to select the second path after transition of the electronic apparatus from the operative state to a non-operative state and control the power supply circuit to supply the power from the battery to the amplifier, when a residual charge capacity of the battery is not less than a predetermined value, the data indicates enabling of audio output, and the first state is detected.

2. The electronic apparatus of claim 1 , wherein

the controller is configured to control the power supply circuit in order to supply the power to the amplifier, when the data indicates enabling of audio output and the first state detector detects the first state after transition of the electronic apparatus to the non-operative state.

3. The electronic apparatus of claim 1 , further comprising:

a second state detector configured to detect a second state where a front surface of the speaker is open, and

wherein the controller is configured to control the power supply circuit in order to supply the power to the amplifier, when the data indicates enabling of audio output and the second state detector detects that the front surface of the speaker is open after transition of the electronic apparatus to the non-operative state.

4. The electronic apparatus of claim 3 , wherein

the controller is configured to control the power supply circuit in order to supply the power to the amplifier, when the data indicates enabling of audio output and the first state and the second state are detected after transition of the electronic apparatus to the non-operative state.

5. An audio signal processing method for an electronic apparatus, the method comprising:

setting data indicating whether audio output from the speaker is enabled or disabled;

detecting whether an external terminal is connected to a terminal supplied with an audio signal from the external apparatus;

inputting the audio signal from the external apparatus through the external terminal connected to the terminal;

switching from a first path, by which an amplifier is connected to a sound controller operating in an operative state, to a second path, by which the terminal and the amplifier are connected to each other without the sound controller, when the data indicates enabling of the audio output, the terminal is connected to the external terminal, and a residual charging capacity of a battery is not less than a predetermined value, after transition of the electronic apparatus from the operative state to a non-operative state; controlling a power supply circuit to continue supplying power from the battery to the amplifier if the power is not supplied externally after the non-operative state starts; and causing the amplifier to amplify the audio signal input to the terminal and outputting the amplified audio signal to the speaker.

6. The method of claim 5 , wherein

when the data indicates enabling of audio output, and the terminal is connected to the external terminal, the power is supplied from the battery to the amplifier, after transition of the electronic apparatus to the non-operative state.

7. The method of claim 5 , wherein

when the data indicates enabling of audio output and the terminal is connected to the external terminal after transition of the electronic apparatus to the non-operative state, after transition of the electronic apparatus to the non-operative state, the power is supplied from the battery to the amplifier.

8. The method of claim 5 , wherein

when the data indicates enabling of audio output and both a state where the terminal is connected to the external terminal and a state where a front surface of the speaker is open are detected after transition of the electronic apparatus to the non-operative state, the power is supplied from the battery to the amplifier.