Sound recording device
View Patent ↗A sound recording device of the present disclosure is can be connected with an external sound pickup device. The sound recording device includes a connector having a plurality of terminals to which the external sound pickup device can be connected, and a determiner that determines a type of the external sound pickup device when the external sound pickup device is connected to the connector, based on a correlation between signals of specific terminals out of the plurality of terminals.
1. A sound recording device to which an external sound pickup device can be connected, the sound recording device comprising:
a connector having a plurality of terminals to which the external sound pickup device can be connected; and
a determiner that determines a type of the external sound pickup device when the external sound pickup device is connected to the connector, based on a correlation between signals of specific terminals of the plurality of terminals, the signals being signals changing temporally while the external sound pickup device is connected to the connector,
the plurality of terminals include a first terminal and a second terminal,
wherein the determiner is configured to determine the correlation between the signals by comparing a first value concerning an output signal of the first terminal and a second value concerning an output signal of the second terminal, wherein the first and second values are obtained by Formula 2, the parameter x is the voltage at the respective one of the first and second terminals, the parameter t represents time, the parameter T 1 represents a first duration, and the parameter T 2 represents a second duration.
f
(
x
(
t
)
)
=
1
T
1
∫
t
1
t
1
+
T
1
x
(
t
)
-
1
T
2
∫
t
2
t
2
+
T
2
x
(
t
)
ⅆ
t
ⅆ
t
.
[
Formula
2
]
2. A sound recording device to which an external sound pickup device can be connected, the sound recording device comprising:
a connector having a plurality of terminals to which the external sound pickup device can be connected; and
a determiner that determines a type of the external sound pickup device when the external sound pickup device is connected to the connector, based on a correlation between signals of specific terminals of the plurality of terminals, the signals being signals changing temporally while the external sound pickup device is connected to the connector,
the plurality of terminals include a first terminal and a second terminal,
wherein the determiner is configured to determine the correlation between the signals by comparing a first value concerning an output signal of the first terminal and a second value concerning an output signal of the second terminal, wherein the first and second values are obtained by Formula 3, the parameter x is the voltage at the respective one of the first and second terminals, the parameter t represents time, the parameter N 1 represents a first duration, the parameter N 2 represents a second duration, the parameter p represents a first constant value and the parameter q represents a second constant value.
f
(
x
(
t
)
)
=
{
1
N
1
∑
n
=
t
1
N
1
-
t
1
x
(
t
+
pn
)
}
-
{
1
N
2
∑
n
=
t
2
N
2
-
t
2
x
(
t
+
qn
)
}
.
[
Formula
3
]
3. A sound recording device to which an external sound pickup device can be connected, the sound recording device comprising:
a connector having a plurality of terminals to which the external sound pickup device can be connected; and
a determiner that determines a type of the external sound pickup device when the external sound pickup device is connected to the connector, based on a correlation between signals of specific terminals the plurality of terminals, the signals being signals changing temporally while the external sound pickup device is connected to the connector
wherein
the plurality of terminals include a first terminal L, a second terminal R, and a third terminal C,
the determiner determines a first time varying voltage value [f(al)] associated with the first terminal L. a second time varying voltage value [f(ar)] associated with the second terminal R, and a third time varying voltage value [f(ac)] associated with the third terminal C, and determines that the connected external sound pickup device is a specific external sound pickup device when both the first and second time varying voltage values [f(al)], [f(ar)] are greater than a first predetermined ratio of the third time varying voltage value α*[f(ac)] and less than a second predetermined ratio of the third time varying voltage value β*[f(ac)], α and β being predetermined coefficients.
4. The sound recording device according to claim 3 , wherein the determiner is configured to determine each of the first, second and third time varying voltage values by Formula 2, the parameter x is the voltage at the respective one of the first and second terminals, the parameter t represents time, the parameter T 1 represents a first duration, and the parameter T 2 represents a second duration.
f
(
x
(
t
)
)
=
1
T
1
∫
t
1
t
1
+
T
1
x
(
t
)
-
1
T
2
∫
t
2
t
2
+
T
2
x
(
t
)
ⅆ
t
ⅆ
t
.
[
Formula
2
]
5. The sound recording device according to claim 3 , wherein the determiner is configured to determine each of the first, second and third time varying voltage values by Formula 3, the parameter x is the voltage at the respective one of the first and second terminals, the parameter t represents time, the parameter N 1 represents a first duration, the parameter N 2 represents a second duration, the parameter p represents a first constant value and the parameter q represents a second constant value.
f
(
x
(
t
)
)
=
{
1
N
1
∑
n
=
t
1
N
1
-
t
1
x
(
t
+
pn
)
}
-
{
1
N
2
∑
n
=
t
2
N
2
-
t
2
x
(
t
+
qn
)
}
.
[
Formula
3
]
6. A sound recording device to which an external sound pickup device can be connected, the sound recording device comprising:
a connector having a plurality of terminals to which the external sound pickup device can be connected; and
a determiner that determines a type of the external sound pickup device when the external sound pickup device is connected to the connector, based on a correlation between signals of specific terminals of the plurality of terminals,
the plurality of terminals include a first terminal, a second terminal, and a third terminal, and
the determiner determines if a first value concerning an output signal of the first terminal and a second value concerning an output signal of the second terminal are higher than a first threshold value concerning an output signal of the third terminal and if the first value and the second value are less than a second threshold value concerning an output signal of the third terminal and determines that the connected external sound pickup device is a specific external sound pickup device when both the first and second values are higher than the first threshold value and less than the second threshold value.
7. The sound recording device according to claim 6 , wherein
the first terminal is a terminal to which a first external sound pickup device t picks up sound from a front direction is connected,
the second terminal is a terminal to which a second external sound pickup device that picks up sound from a left direction is connected, and
the third terminal is a terminal to which a third external sound pickup device that picks up sound from a right direction is connected.
8. The sound recording device according to claim 7 , wherein
the specific external sound pickup device includes the first external sound pickup device, the second external sound pickup device, and the third external sound pickup device.