JP4862995B2 - Speaker lighting device and speaker system using the same - Google Patents

Description

  The present invention relates to a speaker illumination device that illuminates a speaker by changing a light emission amount corresponding to the amplitude of an audio signal, and a speaker system using the same.

  In a speaker system in which a speaker is connected to an amplifier circuit that amplifies the power of an audio signal, a visual stimulus is provided in addition to an auditory stimulus at the time of sound reproduction by providing an illuminating device that changes the amount of light emission according to the amplitude of the audio signal. Is intended to give the listener a greater effect.

  Typically, in order to change the amount of light emission according to the output signal voltage (or current) of the amplifier circuit applied to the voice coil of the speaker, it is directly connected to the output of the amplifier circuit, that is, the speaker voice coil. There are speaker lighting devices that connect directly to. In such a speaker lighting device, if the speaker lighting device is connected in series with the voice coil of the speaker, the fidelity of the speaker reproduction sound with respect to the output voltage of the power amplifier tends to be impaired.

  Therefore, for example, conventionally, a speaker in which a light emitting diode (LED) and a resistor are connected in series may be connected in parallel to a voice coil of a speaker (Patent Document 1). Moreover, the serial connection of LED and a resistor may be connected in parallel with respect to the voice coil of a speaker via a transformer (patent document 2). However, in these conventional examples, the dynamic range of the audio signal applied to the speaker is not considered, and when the resistance value of the resistor connected in series is set so that an appropriate current flows through the LED at the time of large input, At the time of small input, the light emission amount of the LED may be extremely small. On the other hand, if the resistance value is set so that an appropriate current flows through the LED with respect to the speaker input corresponding to the normal listening volume, an excessive current flows at the time of a large input, which causes the destruction of the LED or the resistor. It may become. Conventionally, there is a problem that it may be difficult to cope with such a wide dynamic range of an audio signal.

  Further, conventionally, a circuit for winding an LED driving voice coil that is electromagnetically coupled to a voice coil of a speaker and causing an induced current generated in the light emitting diode driving voice coil to flow through the LED is configured. A constant current diode may be connected in series in the circuit (Patent Document 3). However, in this case, since the coil is wound substantially at the same position as the voice coil, the induced current generated in the LED driving voice coil located in the magnetic gap is the same as that of the voice coil. There is a problem that the operation of the speaker diaphragm is affected, and as a result, the fidelity of the reproduced sound from the speaker is impaired.

JP 2000-217185 A (FIG. 3) JP 59-230396 A (FIG. 3, FIG. 4, FIG. 5) JP 2001-95074 A (FIGS. 3 and 4)

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention relates to a speaker lighting device and a speaker system using the same, and a small input without impairing the fidelity of speaker playback sound. Set the light emission amount of the LED appropriately in a wide range from large to large, and the LED or resistor will not be destroyed even at the large input, and as a result, a greater effect for the listener corresponding to the audio signal It is in providing the speaker illuminating device which can give.

  The speaker illumination device of the present invention is a speaker illumination device that is connected in parallel with a speaker to an audio output terminal of an amplifier circuit that outputs an audio signal to the speaker, and positive and negative audio input terminals connected to the audio output terminal; DC input terminal connected to DC power supply terminal of amplifier circuit, constant current limiting means and switch means connected in series between positive and negative audio input terminals, and connected in series between DC input terminal and switch means And a switch means including a switching element in which a primary side connected to the constant current limiting means and a secondary side connected to the light emitting means are electrically insulated.

  Preferably, in the speaker lighting device of the present invention, the constant current limiting means includes a first constant current limiting means for passing a constant current with a positive voltage applied between the positive and negative audio input terminals, and a negative voltage. Second constant current limiting means for allowing a constant current to pass through, the switch means having a first switching element whose primary side is connected to the first constant current limiting means, and whose primary side is connected to the second constant current limiting means. And the secondary side of each of the first switch element and the second switch element is connected to the light emitting means.

  Preferably, in the speaker lighting device of the present invention, the switch means includes a photocoupler in which the primary LED and the secondary transistor are electrically insulated, and the light emitting means is connected in series to the light emitting diode and the light emitting diode. Includes resistors.

  More preferably, in the speaker lighting device of the present invention, the constant current limiting means includes a constant current diode.

  Preferably, in the speaker lighting device of the present invention, the constant current limiting means switches from the reverse voltage applied between the positive and negative audio input terminals in the direction opposite to the forward voltage defined by the constant current limiting means. It includes a protection diode that protects the device.

  Preferably, in the speaker illumination device of the present invention, the switch means further includes a transistor connected to the secondary side of the switch element and the light emitting means.

  In the speaker system of the present invention, the switch means further includes a logic circuit connected to the secondary side of the switch element and the transistor.

  The speaker system of the present invention includes the above-described speaker illumination device, a speaker illuminated by the light emitting means of the speaker illumination device, and an amplifier circuit that outputs an audio signal to the speaker.

  The operation of the present invention will be described below.

  The speaker illumination device of the present invention is used by connecting the positive and negative voice input terminals in parallel with the voice coil of the speaker to the voice output terminal of the amplifier circuit that outputs the voice signal to the speaker. Between these positive and negative audio input terminals, constant current limiting means and switch means are connected in series. The speaker illumination device further includes a DC input terminal connected to the DC power supply terminal of the amplifier circuit, and the light emitting means is connected in series between the DC input terminal and the switch means. When a voltage higher than the set value is applied to the constant current limiting means, the switch means connected in series is turned on, a direct current is passed through the light emitting means, and the light emitting means emits light.

  Therefore, since the speaker lighting device of the present invention is connected in parallel with the voice coil of the speaker, the fidelity of the speaker reproduction sound is not impaired. In addition, the speaker system using the speaker illumination device of the present invention emits light emitting means corresponding to the audio signal output from the amplifier circuit to the voice coil of the speaker, and gives a visual stimulus to the listener. A production effect can be given. In particular, when the diaphragm of the speaker system is illuminated by the light emitting means of the speaker illuminating device, the light emitting means emits light in conjunction with the operation of the front and rear of the diaphragm, so the effect is great.

  The switch means is a switch element in which the primary side connected to the constant current limiting means and the secondary side connected to the light emitting means are electrically insulated. Specifically, the switch means is a photocoupler, and may further include a logic circuit or a transistor connected to the secondary side transistor of the photocoupler in some cases. The light emitting means includes a light emitting diode (LED) and a resistor connected in series to the LED. The constant current limiting means includes a constant current diode or a junction FET connected between the gate and the source. The constant current limiting means includes a protection diode that protects the photocoupler from a reverse voltage applied between the positive and negative audio input terminals in a direction opposite to the forward voltage defined by the constant current limiting means.

  Here, when the constant current limiting means is a constant current diode, current starts to flow in one direction when the voltage across the constant current diode exceeds a predetermined value, and when the voltage further increases, the voltage exceeds the predetermined voltage value. Then, it becomes a constant current. When the constant current diode and the primary LED of the photocoupler are connected in series with the speaker voice coil in parallel, the voltage of the audio signal applied to both ends of the voice coil becomes the primary voltage of the constant current diode and the primary coupler of the photocoupler. When the sum with the forward voltage of the side LED is exceeded, current begins to flow between the collector and emitter of the secondary transistor of the photocoupler. The current flowing through the primary side LED of the photocoupler continues to increase until the voltage across the constant current diode reaches a predetermined value, and accordingly, the current flowing between the collector and emitter of the secondary side transistor of the photocoupler also increases. In addition, when the voltage across the voice coil of the speaker further increases and the constant current diode starts to operate at a constant current, the primary LED of the photocoupler is turned on unless the voltage exceeds the maximum rated voltage of the constant current diode. The flowing current is a constant current, and the current flowing through the secondary transistor of the photocoupler is also constant.

  When the voltage at both ends of the constant current diode is less than the predetermined value, the constant current diode does not pass current, so there is no audio signal voltage applied to both ends of the voice coil, or there is no signal with a low voltage. Sometimes, no current flows through the primary LED of the photocoupler. Therefore, in this case, no current flows between the collector and the emitter of the secondary transistor of the photocoupler.

  The LEDs constituting the light emitting means are connected in series with a resistor that determines the amount of current of the LED in a direction to be lit by a current flowing through the secondary side transistor of the photocoupler, and a DC power source is connected to both ends thereof. Here, connecting the DC power supply terminal and the DC input terminal of the amplifier circuit literally means connecting the DC power supply terminal and the DC input terminal of the amplifier circuit as well as the DC of a battery or the like as a DC power supply. Including the case where the battery is connected to the DC input terminal. Therefore, with respect to the audio signal voltage applied to both ends of the voice coil of the speaker, it is possible to obtain an illumination effect that follows the magnitude of the audio signal from a certain low voltage, and set a certain limiter for the amount of illumination light. be able to. As a result, the speaker illumination device of the present invention can give a visual stimulus to the listener and provide a greater effect.

  Note that the speaker lighting device of the present invention further includes a transistor connected to the secondary side transistor of the photocoupler of the switch means even when a plurality of light emitting diodes (LEDs) are used, so that a sufficient amount of light emission can be achieved for the effect. Can be obtained. Note that the photocoupler may include a transistor connected to Darlington. In the case of further comprising a logic circuit and a transistor connected to the secondary side transistor of the photocoupler of the switch means, so-called digital on / off with a predetermined voltage of the audio signal applied to both ends of the voice coil of the speaker as a threshold value Lighting effect can be obtained.

  The speaker illumination device of the present invention is connected in series between the first constant current limiting means and the first switch means connected in series between the positive and negative audio input terminals and the positive and negative audio input terminals. The second constant current limiting means and the second switch means, and the light emitting means connected in series between the DC input terminal and the first switch means and the second switch means may be provided. If the current flow from the positive terminal to the negative terminal is positive, the first constant current limiting means passes the constant current with a positive voltage applied between the positive and negative audio input terminals, and the second constant current limiting means Passes a constant current with a negative direction voltage. Further, the first constant current limiting means is a reverse voltage applied between the positive and negative audio input terminals in a direction opposite to the forward voltage defined by the first constant current limiting means (for example, a negative voltage). A first protection diode that protects the switching element from the positive voltage input terminal, and the second constant current limiting means protects the switching element from a forward voltage (for example, a positive voltage) applied between the positive and negative audio input terminals. A second protection diode may be included for protection. Further, a transistor connected to the secondary side of the first switch means and the second switch means may be provided.

  Therefore, the speaker lighting device of the present invention can provide a protective diode for protecting the switch element against positive and negative audio signal voltages applied to both ends of the voice coil of the speaker, regardless of the polarity of the audio signal. An illumination effect that follows the amplitude of the audio signal can be obtained.

  The speaker illumination device of the present invention can appropriately set the light emission amount of the LED in a wide range from a small input to a large input without impairing the fidelity of the reproduced sound of the speaker, and can give a great effect to the listener.

  The speaker lighting device of the present invention has the purpose of appropriately setting the light emission amount of the LED in a wide range from a small input to a large input without impairing the fidelity of the reproduced sound of the speaker, and to give a large effect to the listener. Positive and negative audio input terminals connected to the output terminals, DC input terminals connected to the DC power supply terminals of the amplifier circuit, constant current limiting means and switch means connected in series between the positive and negative audio input terminals, And a light emitting means connected in series between the DC input terminal and the switch means, wherein the switch means is electrically insulated from the primary side connected to the constant current limiting means and the secondary side connected to the light emitting means. This is realized by including a switching element.

  Hereinafter, a speaker illumination device and a speaker system using the same according to preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

  FIG. 1 is a diagram illustrating a speaker system 2 according to a preferred embodiment of the present invention. For example, the speaker system 2 is an amplifier built-in subwoofer system including a speaker illumination device 10 used in a vehicle sound reproduction system, and is connected to the vehicle head unit 1 to constitute a sound reproduction system. The head unit 1 and the speaker system 2 are respectively supplied with a DC voltage + Vcc from a vehicle battery 3. The DC voltage + Vcc of the battery 3 is a positive DC voltage, and a power supply + 12V or + 24V is frequently used. In the present embodiment, the case where there is only one channel of the audio signal (that is, a monaural signal) is shown in the figure. However, the audio signal is not limited to a monaural signal, but in the case of a stereo signal including left and right signals. A reproduction channel corresponding to the number of audio signal channels may be provided. Further, when the reproduction band is a low-frequency component, the subwoofer 10 with a built-in amplifier may mix a stereo signal into a monaural signal.

  The speaker system 2 includes a woofer 4, an amplifier 6 connected to the head unit 1 and the woofer 4, and a speaker illumination device 10. The speaker illumination device 10 further includes an illumination drive unit 11, a light emitting diode ( LED) 12 and an illumination unit. In the speaker system 2, the DC voltage + Vcc of the battery 3 is supplied to the terminal 9 provided in the speaker system 2, and the terminal 8 is grounded. That is, the DC voltage + Vcc of the battery 3 is supplied to the amplifier 6 and the illumination driving unit 11. The audio signal output from the head unit 1 is input to the input terminal 7 of the amplifier 6 and amplified, input from the positive and negative audio output terminals (+, −) to the input terminal of the woofer 4, The light is also branched and input to the illumination driving unit 11. That is, the speaker lighting device 10 is connected in parallel to the audio output terminal of the amplifier 6 with respect to the woofer 4, and the woofer 4 performs electroacoustic conversion of the audio signal and vibrates the diaphragm to reproduce the audio. The woofer 4 is illuminated based on the above.

  Moreover, LED12 of the speaker illuminating device 10 is provided in the front baffle side of the cabinet 5 in which the woofer 4 is attached so that the diaphragm of the woofer 4 may be illuminated. The cabinet 5 to which the woofer 4 is attached separates the space before and after the diaphragm of the woofer 4 to define the acoustic capacity necessary for low-frequency reproduction, and may include the amplifier 6 and the speaker illumination device 10. . Further, the LED 12 may be provided inside the cabinet 5 or on the rear side of the diaphragm of the woofer 4 so as to be transmitted through a transmitted light portion provided in the diaphragm of the woofer 4 or the cabinet 5.

  FIG. 2 is a diagram for explaining in detail the illumination driving unit 11 constituting the speaker illumination device 10 according to the first embodiment. As described above, the illumination driving unit 11 is connected to the woofer 4 in parallel. That is, the amplified audio signals output from the positive and negative audio output terminals (+, −) of the amplifier 6 (not shown) are input to the woofer 4, while the illumination driving unit 11 of the speaker illumination device 10. Are also input to the positive and negative audio input terminals (13 and 14). Between the audio input terminals 13 and 14 of the illumination drive unit 11, a constant current diode 15, a primary side LED 16 a of the photocoupler 16 that is electrically insulated from a secondary side connected to the LED 12, and a protection diode 17 Are connected in series. The secondary side transistor 16b of the photocoupler 16 is grounded at the emitter side via the terminal 20 and connected at the collector side to the LED 12. The direct current voltage + Vcc of the battery 3 is supplied to the LED 12 through the terminal 18 and the resistor 19.

  FIG. 3 is a diagram for explaining the current (B) flowing through the voice coil of the woofer 4 and the currents (C) and (D) in the speaker illumination device 10 when the voltage (A) of the audio signal is a sine wave. is there. In the diode, when a positive voltage applied when a current flows from positive to negative is a forward voltage, and a negative voltage opposite to the positive voltage is a reverse voltage, the constant current diode 15 has a forward voltage of a certain value or more. Then, the current starts to flow in one direction, and when the voltage further increases, the flowing current is limited to a constant current above a certain value. In the illumination drive unit 11, the constant current diode 15 and the primary side LED 16 a of the photocoupler 16 are connected in series, so that the forward voltage (that is, positive) of the audio signal (voltage (A)) input to the woofer 4. Voltage) exceeds the sum of the operation start voltage of the constant current diode 15 and the operation start voltage of the primary side LED 16a of the photocoupler 16, the current flows between the collector and emitter of the secondary side transistor 16b of the photocoupler 16. The flow begins (current (C)), that is, the photocoupler 16 is turned on. Since the direct current voltage + Vcc of the battery 3 is supplied to the LED 12 via the resistor 19, a direct current flows through the LED 12 (current (D)). As a result, the LED 12 emits light and illuminates the woofer 4. When the photocoupler 16 is used, a switching operation is possible even with a DC signal, so that the lighting effect linked to the audio signal can be applied even to an audio signal with a very low frequency, which is a problem in a conventional circuit using a transformer or a coupling coil. Can be obtained.

  For example, when the voltage (A) of the audio signal is a sine wave of 1 kHz and about 2.83 Vrms, the current (B) flowing through the voice coil (DC resistance of about 4Ω) of the woofer 4 is as large as 1.0 A (peak). Become. When a forward voltage is applied to the woofer 4, the current (C) flowing through the primary LED 16a of the photocoupler 16 continues to increase until the voltage across the constant current diode 15 reaches a certain value, and accordingly The current (D) flowing between the collector and emitter of the secondary side transistor 16b of the photocoupler 16 also increases. Further, when the voltage across the constant current diode 15 increases and the constant current diode 15 operates at a constant current (about 3 mA), unless the voltage exceeds the maximum rated voltage of the constant current diode 15, the photo diode The current (C) flowing through the primary LED 16a of the coupler 16 becomes a constant current (about 3 mA), and the current (D) (about 7 mA) flowing between the collector and emitter of the secondary transistor 16b of the photocoupler 16 is also constant. Therefore, the speaker lighting device 10 can cause the LED 12 to emit light according to the amplitude of the audio signal input to the woofer 4, thereby giving a visual stimulus to the listener and providing a greater presentation effect.

  The LED 12 is connected in a lighting direction by a direct current (D) flowing through the secondary side transistor 16b of the photocoupler 16, and the amount of light emission is connected in series with the secondary side transistor 16b and flows through the LED 12 (D ) Is adjusted by a resistor 19 for determining. Therefore, it is possible to obtain an illumination effect that follows the audio signal voltage from a voltage at which the voltage of the audio signal input to the woofer 4 is somewhat low. Also, a certain limiter can be set for the amount of illumination of the LED 12. The light amount (current (D)) of the LED 12 changes according to the voltage (A) of the audio signal until the voltage (A) of the audio signal input to the woofer 4 reaches a certain voltage after the LED 12 starts to light. Above the voltage of a certain audio signal, the light quantity (current (D)) of the LED 12 becomes constant, and an illumination operation in consideration of the dynamic range of the audio signal can be obtained.

  In the speaker illumination device 10 of the present embodiment, a protection diode 17 is connected in series to the constant current diode 15 and the primary LED 16 a of the photocoupler 16. Since the characteristic of the constant current diode 15 with respect to the reverse voltage is generally almost the same as that of the forward diode of the rectifier diode, the voltage of the audio signal input to the woofer 4 is the reverse of that of the primary LED 16a of the photocoupler 16. When it is assumed that the sum of the direction voltage and the reverse voltage of the constant current diode is exceeded, it is preferable to connect the protection diode 17 in series. Thereby, the primary LED 16a of the constant current diode 15 and the photocoupler 16 is prevented from being destroyed due to exceeding the rated value of the reverse voltage, and from the woofer 4 when the voltage of the audio signal input to the woofer 4 is small. It is possible to avoid a situation in which the photocoupler 16 is turned off and the LED 12 is not lit even when sound is reproduced. When the audio signal is small due to the setting, the LED 12 does not light up, so that the LED 12 does not simply remain lit when reproducing a larger sound, and the input voltage does not reach a certain input voltage after the LED 12 starts to light up. Accordingly, it is possible to obtain an illumination operation in consideration of the dynamic range of the input signal such that the light amount of the illumination changes and the light amount of the LED 12 becomes constant above a certain input voltage.

  In the speaker lighting device 10, the electrical impedances of the constant current diode 15, the primary LED 16 of the photocoupler 16, and the protection diode 17 that are connected in series are the same even when a forward voltage is applied to the woofer 4. Since the electrical impedance of the voice coil of the woofer 4 connected in parallel is much larger than the current flowing through the woofer 4 (B), the current (C) (current of several mA at maximum) Only flows to the constant current diode 15. Accordingly, it is possible to appropriately set the light emission amount of the LED 12 in a wide range from a small input to a large input without impairing the fidelity of the reproduced sound from the woofer 4, thereby giving a great effect to the listener.

  FIG. 4 is a diagram for explaining in detail the illumination driving unit 11 constituting the speaker illumination device 10 according to the second embodiment. In the second embodiment, description of portions common to the case of the first embodiment (FIG. 2) is omitted. In the speaker illumination device 10 according to the second embodiment, the light emitting means for illuminating the woofer 4 is composed of a plurality of LEDs 12a and LEDs 12b as compared with the case of the first embodiment. A resistor 19a or 19b is connected in series to each of the plurality of LEDs 12a and LED12b, and the light emission amounts of the LEDs 12a and LED12b are independently adjusted.

  A transistor 21 having a larger current capacity than the secondary side transistor 16b is connected to the secondary side transistor 16b of the photocoupler 16 by Darlington connection. That is, the collector-base of the transistor 21 is connected to the collector-emitter of the secondary side transistor 16 b of the photocoupler 16. Since the secondary side transistor 16b of the photocoupler 16 is often not so high in current capacity, when the plurality of LEDs 12a and LEDs 12b are turned on at the same time, the transistor 21 having a large current capacity is connected by Darlington connection, thereby providing an arbitrary current capacity. Can be secured. Therefore, in the speaker illumination device 10 according to the second embodiment, the effect on the woofer 4 can be further enhanced by using the plurality of LEDs 12a and LEDs 12b.

  FIGS. 5A to 5C are diagrams illustrating the configuration of the constant current limiting unit in the illumination driving unit 11 configuring the speaker illumination device 10 according to the second embodiment. In Example 1 and Example 2, the constant current diode 15 of FIG. 5A is used as the constant current limiting unit of the speaker lighting device 10, but other constant current limiting units may be used. Since the actual structure of the constant current diode is almost the same as that in which the gate-source of the junction FET is connected, or in which a resistor for self-bias is connected thereto, these can be replaced. Therefore, in the speaker lighting device 10, the constant current diode 15 in FIG. 5A has a junction type FET connected between the gate and the source in FIG. 5B or between the gate and the source in FIG. You may change into the junction type FET connected through the self-bias resistance.

  FIG. 5D is a diagram for explaining in detail the case where the photocoupler 16 having a different configuration is used in the illumination driving unit 11 constituting the speaker illumination device 10 of the second embodiment. Note that the woofer 4 is omitted in FIG. Here, the photocoupler 16 is a photocoupler having a logic output, and the LED 12 can be turned on by an on / off digital operation with a constant input voltage as a threshold value. The secondary-side NOT circuit 16c of the photocoupler 16 is connected to the DC power supply Vdd, and the output of the secondary-side NOT circuit 16c is input to the NOT circuit 22 that is also connected to the DC power supply + Vdd, and the output of the NOT circuit 22 is , And connected to the base of the transistor 24 through the resistor 23. The emitter side of the transistor 24 is grounded via the terminal 20, and the collector side is connected to the LED 12. The direct current voltage + Vcc of the battery 3 is supplied to the LED 12 through the terminal 18 and the resistor 19.

  In the speaker lighting device 10, when the photocoupler 16 including a transistor on the secondary side is used in the first embodiment or the second embodiment, the current accompanying the forward voltage starts flowing through the constant current diode 15 and then the constant current operation is performed. In the meantime, the light quantity of the LED 12 continuously changed with respect to the voltage of the audio signal input to the woofer 4, but by using a photocoupler 16 having a logic output on the secondary side, it is constant. An on / off digital current can be passed through the LED 12 with the input voltage as a threshold value, and as a result, an illumination effect can be obtained with a binary value of on / off with respect to the threshold value. The threshold value for setting the lighting on / off operation can be easily set by adjusting the DC power supply Vdd, the NOT circuit 22, and the resistor 23. Therefore, the production effect is higher in consideration of the dynamic range of the audio signal. Lighting operation can be set.

  FIG. 6 is a diagram for explaining in detail the illumination driving unit 11 constituting the speaker illumination device 10 of the third embodiment. Also in the third embodiment, description of portions common to the case of the first embodiment (FIG. 2) is omitted. In the speaker illumination device 10 according to the third embodiment, the LED 12 that illuminates the woofer 4 is turned on in response to the positive voltage and the negative voltage, as compared with the first embodiment that corresponds only to the positive voltage having a large amplitude. The illumination driving unit 11 further includes a constant current diode 25, a photocoupler 26, a protection diode 26, and a transistor 28 connected in series.

  Specifically, in addition to the configuration in the first embodiment, the illumination drive unit 11 is connected between the audio input terminals 13 and 14 of the illumination drive unit 11 and the secondary side connected to the constant current diode 25 and the LED 12. When the reverse voltage reverse to the forward voltage through which the current flows through the constant current diode 15 is applied to the primary LED 26a of the photocoupler 26 and the protection diode 27 that are electrically insulated from each other, the constant current diode 25 Are connected in series so that a current flows through them. A transistor 28 is Darlington connected to the secondary side transistor 16b of the photocoupler 16 and the secondary side transistor 26b of the photocoupler 26. The emitter side of the transistor 28 is grounded via the terminal 20, and the collector side is connected to the LED 12. The direct current voltage + Vcc of the battery 3 is supplied to the LED 12 through the terminal 18 and the resistor 19.

  FIG. 7 is a diagram illustrating voltage (A) or currents (B) to (E) in the speaker illumination device 10 according to the third embodiment. In the voltage (A) of the audio signal input to the woofer 4, the constant current diode 25, the photocoupler 26, and the protection diode 26 are connected in series. Therefore, only when a negative voltage with a large amplitude is applied, A current (E) flows through the constant current diode 25, and the photocoupler 26 is turned on. When a positive voltage with a large amplitude is applied, a current (E) flows through the constant current diode 15 and the photocoupler 16 is turned on. Therefore, a current (D) flows between the collector and emitter of the transistor 28 in response to an audio signal having a large amplitude regardless of the forward voltage or the reverse voltage, and the LED 12 is lit by this current (D). That is, the speaker illumination device 10 according to the third embodiment can obtain an illumination effect that follows the amplitude of the audio signal regardless of the polarity of the audio signal.

  In each of the speaker illumination devices 10 according to the first to third embodiments, the light emission amount of the LED 12 having a higher effect can be set in consideration of the dynamic range of the audio signal. Even when the amplitude of the audio signal is large, the LED 12 or the resistor 19 is not destroyed. In addition, since there is a degree of freedom in the design of the direct current that the device of the LED 12 operates, the emission color or light wavelength (red light, green light, blue light, white light) of the LED 12 having different forward current and forward voltage during light emission. Light, ultraviolet light, infrared light) can be freely selected. In particular, when the diaphragm of the woofer 4 includes a phosphor on its surface, the black light LED 12 that emits ultraviolet light can be turned on following the amplitude of the audio signal. There is an effect that the vibration action is more produced and seen.

  Of course, the speaker system 2 using the speaker illumination device 10 is not limited to the subwoofer with a built-in amplifier. The speaker may be a full-range speaker that reproduces the entire band, or may be a tweeter that reproduces the high frequency in some cases. If the speaker illumination device 10 is composed of an illumination unit including an illumination drive unit 11 and an LED 12, the speaker illumination device 10 is combined with an amplifier and a speaker used in an in-vehicle audio reproduction system including a DC power source, so to speak, and so on. Can do. Even in that case, the light emission amount of the LED 12 can be set in a wide range from a small input to a large input without impairing the fidelity of the reproduced sound of the speaker, and a great effect can be given to the listener.

  The speaker illumination device of the present invention can be applied to, for example, a game machine, a pachinko machine, or the like in which a speaker that reproduces sound is not exposed. When the sound is reproduced by the speaker, the LED emits light corresponding to the sound signal, so that a larger effect can be given to the listener.

It is a figure explaining the audio | voice reproduction | regeneration system by preferable embodiment of this invention. Example 1 It is a figure explaining the illumination drive part which comprises the speaker illuminating device of this invention. Example 1 It is a figure explaining the voltage or electric current in the speaker illuminating device of this invention. Example 1 It is a figure explaining the illumination drive part which comprises the speaker illuminating device of this invention. (Example 2) It is a figure explaining the illumination drive part which comprises the speaker illuminating device of this invention. (Example 2) It is a figure explaining the illumination drive part which comprises the speaker illuminating device of this invention. (Example 3) It is a figure explaining the voltage or electric current in the speaker illuminating device of this invention. (Example 3)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Head unit 2 Speaker system 3 Battery 4 Woofer 5 Cabinet 6 Amplifier 10 Speaker illumination device 11 Illumination drive part 12 LED
15, 25 Constant current diode 16, 26 Photocoupler 17, 27 Protection diode

Claims (7)

A speaker lighting device connected in parallel with the speaker to an audio output terminal of an amplifier circuit that outputs an audio signal to the speaker,
Positive and negative audio input terminals connected to the audio output terminal, a DC input terminal connected to the DC power supply terminal of the amplifier circuit, and a constant current limiting means connected in series between the positive and negative audio input terminals And switch means, and light emitting means connected in series between the DC input terminal and the switch means,
A photocoupler in which the switch means has a primary side LED and a secondary side transistor as a switch element in which a primary side connected to the constant current limiting means and a secondary side connected to the light emitting means are electrically insulated. Including
The light emitting means includes a light emitting diode and a resistor connected in series to the light emitting diode;
Speaker lighting device. The constant current limiting means is a first constant current limiting means for passing a constant current with a positive voltage applied between the positive and negative audio input terminals, and a second constant current limit for allowing a constant current to pass with a negative voltage. Means, and
The switch means includes a first switch element whose primary side is connected to the first constant current limiting means, and a second switch element whose primary side is connected to the second constant current limiting means;
The speaker illumination device according to claim 1, wherein secondary sides of the first switch element and the second switch element are connected to the light emitting means, respectively. The constant current limiting means comprises a constant current diode, a speaker illumination device according to claim 1 or 2. The constant current limiting means further includes a protection diode that protects the switching element from a reverse voltage applied between the positive and negative audio input terminals in a direction opposite to a forward voltage defined by the constant current limiting means. The speaker illumination device according to any one of claims 1 to 3 . It said switch means, further comprising the transistor connected to the secondary side and the light emitting means of the switching element, the speaker illumination device according to any one of claims 1 to 4. The speaker illumination device according to claim 5 , wherein the switch means further includes a logic circuit connected to the secondary side of the switch element and the transistor. It includes a speaker illumination device according to any one of claims 1 to 6, and speaker that are illuminated by the light emitting means of the speaker illumination device, an amplifier circuit for outputting an audio signal to the speaker, the speaker system.

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