JP3146832B2 - In-vehicle speaker device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle speaker device used as a sound reproducing device mounted on a car.

[0002]

2. Description of the Related Art A conventional vehicle-mounted speaker device of this type will be described with reference to the drawings.

FIG. 6 shows the above-mentioned conventional vehicle-mounted speaker device,
FIG. 2 is a block diagram showing a configuration of an on-vehicle sound reproducing device to which the on-vehicle speaker device is connected. In the drawing, reference numeral 22 denotes an on-vehicle sound reproducing device such as a radio or a tape deck mounted on a vehicle body. Sound reproduction device 22 includes an external device drive control circuit 24 driven by a DC power supply 23.
And a balanced transformerless (hereinafter referred to as BTL) power amplifier 25.
An output signal is taken out through a TL output positive terminal 26 and a BTL output negative terminal 27, and this output is applied to a separately mounted speaker 28.

[0004] Reference numeral 29 denotes an in-vehicle speaker device.
The in-vehicle speaker device 29 includes a switching circuit 30 that operates by using a DC signal output from the external device drive control circuit 24 of the in-vehicle sound reproducing device 22 as an input, and a speaker 31 that is driven by the output of the switching circuit 30 to be driven.
And an output signal of the BTL power amplifier 25 of the on-vehicle sound reproducing device 22. The driving unit includes a voltage control amplifier 32 and a power amplifier 33, which are input as audio signal inputs.

In the same figure, 34 is a signal input positive terminal, 35 is a signal input negative terminal, 36 is a drive control input terminal,
Reference numeral 37 denotes a dedicated wiring for connecting the output signal of the external device drive control circuit 24 to the in-vehicle speaker device 29. The in-vehicle sound reproduction device 22 and the in-vehicle speaker device 29 are provided with a common DC power supply 23 and a ground. It has become.

[0006] The operation of the conventional vehicle-mounted speaker device 29 configured as described above will be described.

First, the on-vehicle sound reproducing device 22 is driven to enter an output operation state for the speaker 28, and the built-in external device drive control circuit 24 rises and outputs a DC voltage signal. The output DC voltage signal is input as a control signal to a drive control input terminal 36 of a switching circuit 30 of an in-vehicle speaker device 29 which is an external device, and the switching circuit 30 is driven. When the power is supplied, the in-vehicle speaker device 29 enters an output operation state, and the signal amplified by the power amplifier 33 is applied to the speaker 31 to reproduce sound.

[0008]

However, in the above-mentioned conventional configuration, in order to drive the in-vehicle speaker device 29, a signal for driving the in-vehicle speaker device 29 externally mounted in the in-vehicle sound reproduction device 22 is provided. Since the external device drive control circuit 24 for outputting the signal and the dedicated wiring 37 to the output terminal and the in-vehicle speaker device 29 are required, the number of parts increases and the cost increases.

[0009] Some of the on-vehicle sound reproducing devices 22 include:
Some devices are not originally equipped with the external device drive control circuit 24 or its output terminal, and if there is a setting to separately mount the in-vehicle speaker device 29 having a built-in audio amplifier, etc. In order to prevent the battery from running out, it is necessary to newly install a manual switch or a device that replaces the manual switch, which also increases the cost.

The present invention solves such a conventional problem,
It is an object of the present invention to provide an in-vehicle speaker device whose configuration is simplified and cost is reduced.

[0011]

In order to solve the above-mentioned problems, a vehicle-mounted speaker device according to the present invention connects positive and negative BTL output signals output from a vehicle-mounted sound reproducing device having a BTL power amplifier. And an impedance element for taking out only a DC component by adding the signals, a switching circuit for driving a signal passing through the impedance element as an input, and a driving unit for driving the output of the switching circuit to apply a signal to a speaker. It was done.

[0012]

With this configuration, by adding the positive / negative BTL output signal output from the on-vehicle sound reproducing device and the impedance element, only the AC signal component can be canceled and only the DC signal component can be extracted. Since the driving unit can be driven by driving the switching circuit of the in-vehicle speaker device with the signal, the in-vehicle speaker device with a simplified configuration can be realized.

[0013]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an on-vehicle speaker device according to the embodiment and an on-vehicle sound reproducing device to which the on-vehicle speaker device is connected.
Denotes an on-vehicle sound reproducing device such as a radio or a tape deck mounted on a vehicle body. The on-vehicle sound reproducing device 1 has a built-in BTL power amplifier 3, and the BTL power amplifier 3
, Through a BTL output positive terminal 4 and a BTL output negative terminal 5, and applies the extracted output signal to a separately mounted speaker 2.

Reference numeral 6 denotes an in-vehicle speaker device of the present invention connected to the in-vehicle sound reproducing device 1, and the in-vehicle speaker device 6 is a BTL of the in-vehicle sound reproducing device 1.
Impedance elements 12 and 13 to which an output signal from the power amplifier 3 is connected as an input signal, a switching circuit 14 which operates with an output signal of the impedance elements 12 and 13 as an input, and a switching circuit 14
A drive unit composed of a voltage control amplifier 8 and a power amplifier 9 which are driven by the output of the above and apply an output signal to the speaker 7 and the output signal of the BTL power amplifier 3 of the on-vehicle sound reproducing device 1 is input as an audio signal. It consists of.

In FIG. 1, reference numeral 10 denotes a signal input positive terminal, 11 denotes a signal input negative terminal, 15 denotes a drive control input terminal,
Reference numeral 16 denotes a DC power supply.

The operation of the vehicle-mounted speaker device according to the present invention configured as described above will be described below.

First, the on-vehicle sound reproducing device 1 is driven to be in an output operation state with respect to the speaker 2, and an output signal from the BTL power amplifier 3 in the on-vehicle sound reproducing device 1 is input to a signal input of the on-vehicle speaker device 6. Positive terminal 10, negative terminal 11
Are input to the impedance elements 12 and 13 via the.
At this time, a DC voltage of about half of the power supply (battery) voltage is applied between the grounds at the BTL output positive / negative terminals 4 and 5 which relay the output from the BTL power amplifier 3 input to the vehicle-mounted speaker device 6. This signal is
Only a DC component is extracted from the negative terminals 10 and 11 and used as a control signal for the switching circuit 14.

When the power supply voltage is, for example, 12 V, the BT
Output positive / negative terminals 4 of the L-connected BTL power amplifier 3,
A DC voltage of about 6 V is applied to the ground 5 and the ground, and AC signals oscillate in opposite phases with respect to the voltage. These two signals are converted to impedance elements 12 and 13
, AC components having mutually opposite phases are removed, and only a DC component (about 6 V) can be extracted.

The DC component is input to the drive control input terminal 15 to drive the switching circuit 14, whereby power is supplied to the voltage control amplifier 8 and the power amplifier 9 to operate the on-vehicle speaker device 6, and the speaker 7 It can play sound.

As described above, the in-vehicle speaker device 6 according to the present invention generally has the above-described in-vehicle acoustic device when the in-vehicle speaker device 6 is mounted on the in-vehicle audio reproduction device 1 mounted on the vehicle body and driven. Although the external device drive control circuit and the exclusive wiring for connecting the external device drive control circuit and the in-vehicle speaker device 6 are required in the reproducing device 1, the in-vehicle speaker device is not required at all. 6 can be driven, the circuit configuration can be simplified, and the cost can be reduced.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of the vehicle-mounted speaker device according to the embodiment.
Since the capacitor element 17 is connected in front of the drive control input terminal 15 of the switching circuit 14 of the in-vehicle speaker device shown in the second embodiment, the configuration is the same as that of the first embodiment except for this configuration. The detailed description is omitted, and only different portions will be described.

In FIG. 2, reference numeral 6A denotes an in-vehicle speaker device according to the embodiment, and reference numeral 17 denotes a capacitor element connected before the drive control input terminal of the switching circuit 14. The elements 12, 13 and the capacitor element 17 operate as a low-pass filter, and it is possible to remove a ripple signal leaking when adding a BTL output signal.
The DC voltage signal is stabilized as a drive control signal for the switching circuit 14, so that the in-vehicle speaker device 6A can be operated more stably.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a block diagram showing the configuration of the vehicle-mounted speaker device according to the embodiment.
The diode element 1 is connected between the output of the impedance elements 12 and 13 and the capacitor element 17 connected before the switching circuit 14 of the in-vehicle speaker device shown in the embodiment.
8 are connected. Since the configuration other than this configuration is the same as that of the second embodiment, detailed description is omitted, and only different portions will be described.

In FIG. 3, reference numeral 6B denotes an in-vehicle speaker device according to the embodiment, and reference numeral 18 denotes a diode element connected between the output of the impedance elements 12 and 13 and the capacitor element 17 connected before the switching circuit 14. With such a configuration, it is possible to stop the backflow of the DC current charged in the capacitor element 17 and to perform switching even when the DC potential of the BTL power amplifier fluctuates between lower and upper instantaneously. The effect on the operation of the circuit 14 is reduced, and the circuit 14 can be operated stably.

(Embodiment 4) Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 4 is a block diagram showing the configuration of a vehicle-mounted speaker device according to the embodiment.
Since the constant voltage diode element 19 is connected in front of the switching circuit 14 of the in-vehicle speaker device shown in the third embodiment, the configuration is the same as that of the first embodiment except for this configuration. Are omitted, and only different portions will be described.

In FIG. 4, reference numeral 6C denotes an in-vehicle speaker device according to the embodiment. Reference numeral 19 denotes a constant-voltage diode element connected in front of the switching circuit 14. With this configuration, the rise of the BTL power amplifier is achieved. In addition, it is possible to set and remove the potential of a ripple noise component generated by an offset voltage or the like generated at the time of a fall, thereby enabling a more stable operation.

In the above embodiment, the switching circuit 1
4, a constant voltage diode element 19 is connected to the preceding stage. However, the present invention is not limited to this, and is combined with the capacitor element 17 and the diode element 18 shown in the second and third embodiments. Needless to say, similar effects can be obtained by using the same.

Embodiment 5 Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings.

FIG. 5 is a block diagram showing the structure of the vehicle-mounted speaker device according to the embodiment.
A light emitting diode element 20 and a current control resistor 21 for flowing a predetermined current through the light emitting diode element 20 are connected in front of the switching circuit 14 of the in-vehicle speaker device shown in the embodiment. Other than this configuration, the configuration is the same as that of the first embodiment. Therefore, detailed description is omitted, and only different portions will be described.

In FIG. 5, reference numeral 6D denotes an in-vehicle speaker device according to the embodiment. Reference numeral 20 denotes a light emitting diode element connected in front of the switching circuit 14, and 21 denotes a current control for flowing a predetermined current through the light emitting diode element 20. With this configuration, the DC voltage component extracted by the impedance elements 12 and 13 is supplied to the light emitting diode element 20 via the current control resistor 21 so that the light emitting diode element 20 emits light. . Thus, it is possible to extremely easily confirm that the in-vehicle speaker device 6D is operating.

In the above embodiment, the switching circuit 1
4, a light emitting diode element 20 and a current control resistor 21
However, the present invention is not limited to this, and is combined with the capacitor element 17, the diode element 18, and the constant voltage diode element 19 shown in the second, third, and fourth embodiments. It is needless to say that the same effect can be obtained by using the same.

[0036]

As described above, the in-vehicle speaker device according to the present invention extracts only the DC component by adding the positive and negative BTL output signals output from the in-vehicle sound reproducing device by the impedance element, and drives this. By using it as a control signal, it is possible to realize a simple and inexpensive in-vehicle speaker device having a configuration that does not require a special control circuit or dedicated wiring.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle-mounted speaker device according to a first embodiment of the present invention and a vehicle-mounted sound reproduction device to which the speaker device is connected;

FIG. 2 is a block diagram showing a configuration of an in-vehicle speaker device according to the second embodiment;

FIG. 3 is a block diagram showing a configuration of a vehicle-mounted speaker device according to a third embodiment;

FIG. 4 is a block diagram showing a configuration of an in-vehicle speaker device according to a fourth embodiment;

FIG. 5 is a block diagram showing a configuration of an in-vehicle speaker device according to a fifth embodiment;

FIG. 6 is a block diagram showing a configuration of a conventional in-vehicle speaker device and an in-vehicle sound reproducing device connected thereto;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 vehicle-mounted sound reproducing device 2 speaker 3 BTL power amplifier 4 BTL output positive terminal 5 BTL output negative terminal 6, 6A, 6B, 6C, 6D vehicle-mounted speaker device 7 speaker 8 voltage control amplifier 9 power amplifier 10 signal input positive terminal 11 Signal input negative terminal 12, 13 Impedance element 14 Switching circuit 15 Drive control input terminal 16 DC power supply 17 Capacitor element 18 Diode element 19 Constant voltage diode element 20 Light emitting diode element 21 Current control resistor

Continuation of the front page (56) References JP-A-61-103254 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04R 3/00 310 B60R 11/02 H04R 3/04 H04R 3/12

Claims (5)

(57) [Claims] 1. An impedance element for connecting and adding positive and negative output signals output from an on-vehicle sound reproducing apparatus having a balanced transformerless power amplifier and extracting only a DC component, and passing through the impedance element A vehicle-mounted speaker device comprising: a switching circuit that drives the received signal as an input; and a drive unit that is driven by an output of the switching circuit and applies a signal to a speaker. 2. The in-vehicle speaker device according to claim 1, wherein a capacitor element is connected before the switching circuit. 3. The in-vehicle speaker device according to claim 2, wherein a diode element is connected between a capacitor element connected before the switching circuit and an output of the impedance element. 4. The in-vehicle speaker device according to claim 1, wherein a constant voltage diode element is connected to a stage preceding the switching circuit. 5. The in-vehicle speaker device according to claim 1, wherein a light emitting diode element and a current control resistor for causing a predetermined current to flow through the light emitting diode element are connected to a stage preceding the switching circuit.