GB2260041A

GB2260041A - Sound responsive light blinking device

Info

Publication number: GB2260041A
Application number: GB9209067A
Authority: GB
Inventors: Shuji Hata
Original assignee: JALCO Co Ltd
Current assignee: JALCO Co Ltd
Priority date: 1991-09-30
Filing date: 1992-04-27
Publication date: 1993-03-31
Anticipated expiration: 2012-04-27
Also published as: FR2682255A1; JPH0594884A; FR2682255B1; GB9209067D0; JP2519616B2; GB2260041B; DE4224392A1

Abstract

There is described a light blinking device which is capable of accurately and precisely blinking illuminants in response to music. The device includes a plurality of channels, each having a buffer amplifier 10, a phase lock loop circuit 11 having a lock state detecting circuit (11d), (Fig 2) which generates a digital output signal, a time constant circuit 12, an output circuit 13 and a decorative illuminant 14 which is turned on by an output from the output circuit 13. A common input terminal In receives an audio frequency signal, eg. from a microphone incorporated into the device. The free-running frequencies and capture ranges of the PLL circuits 11 of each of the channels are arbitrarily set to within the audio frequency range so that the free-running frequencies and the capture ranges do not substantially overlap one another. The time constant circuits 12 operate to integrate the output signals from the lock state detecting circuits in the PLL circuits 11 so as to obtain a stable signal which operates the output circuits 13 to turn on the respective illuminants 14. Additional external illuminants, and motors for operating movable displays, may be connected in parallel with the illuminants 14. <IMAGE>

Description

p r 11 - 1 "SOUND RESPONSIVE LIGHT DEVICE" The present invention relates

to a decorative light device which blinks in response to a change in a sound, such as a low-frequency sound of, e.g. , a drum, a high-frequency sound of, e.g., cymbals, or a singing voice of all frequency components contained in music being played or broadcast. This light blinking device may be installed in a suitable venue, such as a so-called "karaoke (do-it-yourself vocals) bar".

In places where music can be heard, such as discotheques and karaoke bars, when visual effects are used to help create an atmosphere, means have hitherto been employed in which illuminants emit light in response to music so as to create an atmosphere which appeals to the human eye and ear.

There is known a device which is operated through computer programmes which are written beforehand in accordance with music, and another device which blinks illuminants in response to the dynamics or to the high and low frequencies of a sound. Such well-known devices are employed when illuminants are appropriately blinked in response to various types of music, such as one in which the sounds of a drum and cymbals and bass and soprano voices are intermixed. The former device operating through programmes is capable of very precisely blinking illuminants in response to music which has already been programmed. Such a device, however, is not capable of immediately coping with music which has not yet been programmed, and thus it lacks versatility. In addition, the device is not suitable for general use because it is expensive, and is therefore only suitable for business use in limited types of places.

The above-referred to device for blinking 2 - illuminants in response to the dynamics of a sound is a device which responds to a sound to blink illuminants regardless of the type of sound, for example, whether it is the sound of a drum or cymbals, as long as the pressure of the sound is the same. When the sound pressure of music happens to be increased at the climax of the music, such a device may operate so as to keep the illuminants continuously turned on, and is thus insufficient for visual effect purposes.

As opposed to the above device, there is known a device for blinking illuminants in response to the frequency of the sound. This device does not have the above problem of the former device, and thus it is versatile and effective in producing visual effects. Such a device will be described below.

Figure 3 of the accompanying drawings is a block diagram showing the functions of a conventional device for blinking illuminants in response to the frequency of a sound. Referring to Figure 3, reference character 20L denotes a low-pass filter; 21, amplifiers; 22, detecting circuits; 23, time constant circuits; 24, voltage comparators; 25, reference voltage applied to the voltage comparators; 26, output circuits; and 27, illuminants. The low-pass filter 20L, the amplifier 21, the detecting circuit 22, the time constant circuit 23, the voltage comparator 24, the output circuit 26, and the illuminant 27 constitute a one-channel functional block correspond- ing to a low frequency of sound. In Figure 3, reference character 20B denotes a bandpass filter; 20B', another bandpass filter having the same circuit structure as that of the bandpass filter 20B and a frequency band different from that of the bandpass filter 20B; and 20H, a high-pass filter. Such a onechannel functional block, which is a light blinking 4 i.

block, is attached to the back of each of the filters.

The number of filters corresponds to the number of frequencies. In Figure 3, like numerals denote the same components in the same functional blocks.

Symbol In denotes a terminal at which an electric music signal is input.

When the electric music signal is input from equipment, such as audio equipment Ad, to the input terminal In, it is first transmitted to the low-pass filter 20L, the high-pass filter 20H, and bandpass filters 20B and 20B' having the different pass bands, and is thus classified according to the frequency set in each respective filter. By this time, since the music signal has been attenuated by an AC resistant component (constituted by the LCR circuit making up each filter), the amplifiers 21, connected to the filters 20L, 20B, 20B' and 20H, amplify the signal.

The output of each amplifier 21 is passed through each detecting circuit 22 to convert it into a DC component, which in turn is converted by each time constant circuit 23 into a voltage level of a direct current.

Voltage outputs from the time constant circuits 23 increase as the frequencies of the electric music signal input through the input terminal In approach the centre frequencies set in the filters 20L, 20B, 20B' and 20H. In other words, when a frequency of all frequencies contained in music is close to the centre frequency of each filter, the level of the voltage output from each time constant circuit 23 increases.

The voltage output from each time constant circuit 23 is input to each voltage comparator 24 to compare it with the reference voltage 25. If the output voltage exceeds the reference voltage 25, the output circuit 26 corresponding to the output voltage is operated to blink the corresponding illuminant 27.

As described previously, when the centre frequencies of the filters are set to the frequency bands of the sound of a drum and cymbals, the above device blinks the illuminants in accordance with such frequency bands. However, the filters used in the device are of a general-purpose type and have approximately -6dB/oct roll-off. Therefore, an audio frequency range (from about 20 Hz to 20 KHz) can be divided into three bands at most when the illuminants are reliably blinked on and off. The number of frequency bands into which the audio frequency range is divided is equal to the number of illuminants blinking on and off. The illuminants do not blink precisely and synchronously in response to the dynamics of the sound of music.

Even if a device overcomes the above problem, filters, each having approximately -18 dB/oct., would have to be utilised because the extent to which amplifiers can amplify the-signal and the accuracy with which voltage comparators can operate are limited. In addition, the circuitry in such a device is complicated. The above audio frequency range can be divided into five bands at most. For this reason, such a device is ineffective in producing visual effects and operates to blink illuminants on and off in a monotonous manner. Also, despite the high cost of the device, it operates in a manner similar to that of a toy, and thus it does not sufficiently satisfy human visual sensitivity.

The present invention seeks to solve the above problems of the conventional devices by providing a compact, low-cost decorative light blinking device which is capable of accurately and precisely blinking illuminants of channels in response to music (the frequency of sound), and which is also capable of - reliably reducing the number of components required for circuitry. An audio frequency range (from 20 Hz to 20 KHz) can be divided into about 10 frequencies.

The present invention provides a decorative light blinking device flashing to music, said device comprising: a plurality of channels, each including a buffer amplifier, a PLL circuit connected to the buffer amplifier and having a lock state detecting circuit which generates a digital output signal, a time constant circuit connected to the PLL circuit, an output circuit connected to the time constant circuit, and a decorative illuminant connected to the output circuit and turned on by an output from the output circuit; and a signal input point into which input terminals of the buffer amplifiers of the channels are formed, and through which an electric music signal is input from audio equipment, free-running frequencies and capture ranges of the PLL circuits of the channels being arbitrarily set to within an audio frequency range so that the free-running frequencies and the capture ranges do not basically overlap with each other, the PLL circuits being set so as to be locked with respect to only frequencies corresponding to the capture ranges which are arbitrarily set in all frequency components constituting the music signal, whereby the time constant circuits integrate an output signal from the lock state detecting circuits in the PLL circuits so as to obtain a stable signal which operates the output circuits to turn on the decorative illuminants.

In order that the invention may be better understood, an embodiment thereof will now be described by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a block diagram showing the functions of an embodiment of a light blinking device 6 according to the present invention; Figure 2 is a block diagram showing the functions of a phase lock loop (PLL) circuit used in the light blinking device of this invention; and Figure 3 is a block diagram showing the functions of a known device.

Referring to Figures 1 and 2, reference numeral 10 denotes buffer amplifiers, and numeral 11 denotes PLL circuits. The input terminal of a phase comparator 11a in each PLL circuit 11 is connected to the output terminal of each buffer amplifier 10. As shown in Figure 2, each PLL circuit 1 1 has a circuit lld for detecting whether the PLL circuit 11 is locked (hereinafter referred to as a lock state detecting circuit 11d). Numeral 12 denotes time constant circuits connected to the PLL circuits 11. The time constant circuits 12 first integrate signals which are output from the lock state detecting circuits 11d and indicate that the PLL circuits are locked. These time constant circuits 12 then convert the signals to voltage level signals and then output them to circuits in the next stage. Numeral 13 denotes output circuits which are connected to the time constant circuits 12 and operated by the signals output from the circuits 12. Numeral 14 denotes illuminants which are connected to the output circuits 13 and turned on by the output circuits 13. Any illuminant can be employed regardless of the method of emitting light, as long as it is capable of radiating visible rays. For instance, LEDS, heating tubes, and discharge tubes, such as neon and fluorescent tubes, may be used as illuminants. Needless to say, each output circuit 13 is constructed corresponding to a method by which each illuminant 14 emits light.

The buffer amplifier 10, the PLL circuit 11, the time constant circuit 12, the output circuit 13 and the illuminant 14 together constitute one light 7 - blinking block LB, which is a one-channel functional block, corresponding to any one of the frequencies in an audio frequency range. For example, when a light blinking device is constructed in such a manner that the audio frequency range of a music signal is divided into, for instance, 10 frequencies, 10 illuminants blink on and off. Thus, a total of 10 parallel light blinking blocks, each forming 1 channel, are provided.

In Figure 1, which shows an embodiment of the light blinking device of this invention, only four light blinking blocks LB, LB 20 LB 3 and LB 101 each forming 1 channel, are illustrated for the sake of convenience of description and representation in the drawing. In Figure 1, like reference characters denote like functional blocks. The input terminals of the buffer amplifiers 10 in the light blinking blocks are formed into one signal input terminal In, to which an electric music signal coming from, for example, audio equipment Ad, is input. 20 In the light blinking device of this invention, the illuminants 14 in the respective light blinking blocks LB to LB 10 controllably blink in correspondence to frequencies into which the audio frequency range (typically 20 Hz to 20 KHz) is divided. The audio frequency range is divided so that in principle these frequencies are not overlapped with each other. Such operation will be described below. In the PLL circuits 11 of the light blinking block LB to LB 101 free-running frequencies of, e.g., 100 Hz, 500 Hz, 1 KHz, 2 KHz, 4 KHz, 6 KHz, 8 KHz, 15 KHz and 18 KHz are set to Voltage- Controlled Oscillator (VC0s) 11b, respectively. Capture ranges used for the free-running frequencies also set to the respective PLL circuits 11. The capture ranges are set to be as small as possible so that the ranges within which the PLL circuits operate their frequencies do not overlap with each other. The oscillation characteristics of each VCO lib are changed or a variable resistor is utilised to adjust 5 the level of a control voltage V 2 applied to each VCO lib, whereby each capture range may be adjusted. In Figure 2, reference character lla denotes a phase comparator which compares in real time the phase of a frequency f 1 with that of a frequency f 2 contained in the music signal. The frequency f 1 is input through each buffer amplifier 10, whereas the frequency f 2 is output through each VCO lib. Reference character lic denotes a loop filter which integrates the output V 1 from the phase comparator lla to generate a positive or negative output voltage V2 having a direct current component. This output voltage V 2 serves as the control voltage applied to the VCO lib. Reference character C 1 denotes a capacitor, and R 1 denotes a resistor, both included in each VCO llb.

When each PLL circuit 11 is locked, it is controlled by the output V 2 from each loop filter lic so that each VCO lib follows the frequency f 1 input to each phase comparator lla. However, when the frequency f 1 input to each phase comparator lla is out of its lock range, each VCO lib is not capable of following the frequency f 1 In other words, each loop filter llc does not generate its output V 2 It is therefore possible to detect whether each PLL circuit 11 is locked or not by detecting whether there is an output V2 from each loop filter llc. Reference character lid denotes a circuit for detecting whether each PLL circuit 11 is locked or not (hereinafter referred to as a lock state detecting circuit lid). This lock state detecting circuit lid is disposed in each PLL circuit 11, and its output is used to detect whether each PLL circuit 11 is locked PTRI ' or not. A detection signal from the lock state detecting circuit 11d is input to each time constant circuit 12.

The free-running frequencies and the capture ranges which are set in the VC0s 11b of the PLL circuits 11 in light blinking blocks LB to LB 10 differ from each other. The free-running frequencies and the capture ranges are within the audio frequency range. The different frequencies are utilised to detect whether the PLL circuits 11 in the light blinking blocks LB to LB 101 each forming a channel, are locked or not. In this way, after it has been detected that each PLL circuit 11 in each light blinking block is locked, the detection signal is output from each lock state detecting circuit 11d to each time constant circuit 12, where it is integrated. An integrated signal operates each output circuit 13 which turns each illuminant 14 on.

Thus, each illuminant 14 is turned on only when each PLL circuit 11 in each light blinking block is locked. Each illuminant 14 is not turned on when each PLL circuit 11 is not locked.

The same music signal is input through the input terminal In to the light blinking blocks LB to LB 10 However, because of the different free-running frequencies and capture ranges which are set in the PLL circuits 11, the illuminants 14 in the light blinking blocks LB to LB 10 flash in a different manner.

In the above embodiment of the light blinking device according to this invention, the free-running frequencies of the VC0s 11b in the respective PLL circuits 11 are set so as not to overlap with each other. However, the free-running frequencies of the VC0s 11b can be set to 12 equal temperament scales on the basis of 440 Hz. Each capture range can be narrowed to within a range where various operations of the PLL circuits 11 are not affected. Such setting and reduction make it possible for the illuminants 14 to blink in correspondence to the 12 equal temperament scales which are contained in the music signal transmitted through the input terminal In. The illuminants 14 blink substantially corresponding to the 12 equal temperament scales of the music, and light comes in harmony with the music.

In the embodiment shown in Figure 1, the output terminal of the audio equipment Ad is connected to the input terminal In of the light blinking device to input the music signal. Instead of the input terminal In, a microphone (not shown) having a microphone amplifier may be attached to the outside of the light blinking device or may be built into it. Because of such a structure, the microphone picks up sound coming from, e.g., a speaker, and converts it into a music signal which is input to the light blinking device.

When the light blinking device having such a microphone is mounted on a vehicle, the microphone may pick up various vibrations, thus resulting in errors in picking up the sound of music. To prevent or control such errors, a vibration-deadening material, such as a damping material, may be appropriately interposed between the microphone and a member to which it is attached.

In this embodiment, the output circuits 13 are 3 0 employed to blink illuminants in correspondence to the different frequencies of a music signal. However, an external output terminal may also be employed to connect additional illuminants and a motor parallel to the illuminants 14. In such a structure, in addition to the illuminants 14, the additional illuminants are blinked, and a movable display device is operated by a 11 - the external motor synchronously with the illuminants 14.

An adaptor (not shown) exclusively used for reception may be disposed in front of the input terminal In and connected to a transmission device. The transmission device sends a music signal to the input terminal In through a transmitting medium, such as light, radiowaves or infrared rays. In this way, the format in which a music signal is transmitted to the input terminal In can be enlarged, thus widening the range within which the light blinking device can be utilised.

As has been described above, according to this invention, PLL circuits are utilised to blink illuminants in correspondence to a plurality of frequencies of an audio frequency range contained in a music signal. The audio frequency range is divided so as not to overlap with each other. As compared with the conventional light blinking device operating synchronously with a music signal, the light blinking device of this invention does not require a band-pass filter or a detecting circuit, which is a circuit component, thus reducing the number of components and assembly time.

The PLL circuits-employed may be fabricated on a single chip because of an IC, and are therefore easily obtained at low cost, thus enhancing the above advantages. The PLL circuits, the characteristics of which are easy to set or modify operational cond- itions, are utilised to operate the output circuits which turn the illuminants on. By setting and modifying these characteristics, the mode in which the illuminants and the like are blinked can be changed in various ways which cannot be realised by the known devices. The light blinking device of this invention can be effectively used as a decorative device.

Claims

1. A light blinking device flashing to music, said device comprising:a plurality of channels, each including a buffer amplifier, a PLL circuit connected to said buffer amplifier and having a lock state detecting circuit which generates a digital output signal, a time constant circuit connected to said PLL circuit, an output circuit connected to said time constant circuit, and an illuminant connected to said output circuit and turned on by an output from said output circuit; and a signal input terminal to which input terminals of said buffer amplifiers of said channels are connected, and through which an electric music signal is input from audio equipment, the free-running frequencies and capture ranges of said PLL circuits of said channels being arbitrarily set to within an audio frequency range so that the free-running frequencies and the capture ranges do not substantially overlap one another, said PLL circuits being set so as to be locked with respect to only frequencies corresponding to said capture ranges which are arbitrarily set in all. requency components constituting said music signal, whereby said time constant circuits integrate an output signal from said lock state detecting circuits in said PLL circuits so as to obtain a stable signal which operates said output circuits to turn on the illuminants. 2. A light blinking device according to claim 1, wherein the free-running frequencies of said PLL circuits are set to 12 equal temperament scales based upon A = a' = 440 Hz, which is defined by an international standard, and wherein the capture ranges of said PLL circuits are narrowed, whereby the Z^ 7 A 13 - illuminants are blinked on and off in correspondence only to said 12 equal temperament scales used in music which is input in the form of the music signal. A light blinking device according to claim 1 further comprising:a microphone incorporated into said device or an input terminal capable of connecting a microphone to said device from the outside; a microphone amplifier; and an input switching device connected to said microphone, whereby said microphone picks up the sound of music output through a speaker, and this sound is converted into the electric music signal which is input to the signal input terminal.

4. A light blinking device according to claim 2, wherein when said device is mounted on a vehicle, a vibration-damping material, such as a sponge material or a glass-wool material, is interposed between said microphone and a housing for said device in order to control errors in picking up the sound of the music, such errors being caused by road conditions and engine vibrations of the vehicle.

5. A light blinking device according to claim 1 further comprising an external output terminal for connecting a motor and additional illuminants in parallel to said illuminants which are connected to said output circuits and incorporated into said device, said additional illuminants being provided outside said device.

6. A light blinking device according to claim 1 further comprising an adaptor exclusively used for receiving a voice signal which is transmitted through transmission equipment utilising an optical fibre cable, radiowaves or infrared rays to transmit the voice signal in a cordless manner, whereby the electric music signal input through said adaptor is 14 - transmitted to said input terminal to operate said device.

7. A light blinking device substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

IF R -A