U.S. patent number 3,927,402 [Application Number 05/531,045] was granted by the patent office on 1975-12-16 for audio responsive light display system.
This patent grant is currently assigned to Maytronics, Inc.. Invention is credited to Marion E. Thompson.
United States Patent |
3,927,402 |
Thompson |
December 16, 1975 |
Audio responsive light display system
Abstract
There is provided an audio responsive light display system in
which one or more light emitting diodes (LED's) are actuated in
response to speaker feedback impulses which modulate a low voltage
direct current connected to the LED's. Speakers having such a
display associated with the speaker housing or grille provides not
only an esthetic combination of visual and audio effects, but
enables one to determine visually the operation of any of a
plurality of speakers responding to audio input.
Inventors: |
Thompson; Marion E. (Colorado
Springs, CO) |
Assignee: |
Maytronics, Inc. (Colorado
Springs, CO)
|
Family
ID: |
24116018 |
Appl.
No.: |
05/531,045 |
Filed: |
December 9, 1974 |
Current U.S.
Class: |
340/815.45;
340/815.46 |
Current CPC
Class: |
A63J
17/00 (20130101) |
Current International
Class: |
A63J
17/00 (20060101); G08B 005/36 () |
Field of
Search: |
;340/384R,261,148,366B
;179/1VL ;84/464 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pitts; Harold I.
Attorney, Agent or Firm: Sheridan, Ross & Fields
Claims
What is claimed is:
1. An audio responsive light display system comprising in
combination;
a speaker responsive to an audio signal for producing a feedback
impulse;
a displayed light emitting diode;
an external low voltage dc source for lighting said light emitting
diode and connected thereto; and
means for modulating the current flow from said dc source to said
light emitting diode in response to said feedback impulse.
2. An audio responsive light display system in accordance with
claim 1 wherein:
the speaker includes a housing and a light emitting diode is
mounted on the housing.
3. An audio responsive light display system in accordance with
claim 1 wherein:
the low voltage dc source is less than 10 volts.
4. An audio responsive light display system in accordance with
claim 1 further including:
a plurality of light emitting diodes connected in separate parallel
paths with said low voltage dc source.
5. An audio responsive light display system in accordance with
claim 4 wherein:
said modulating means includes resistor means in each parallel path
of different value so that different levels of feedback impulse are
required to light said light emitting diode in each path.
6. In an audio responsive light display system including a speaker,
a housing therefore, a source of an audio signal for driving said
speaker, and a visible light emitting source, the intensity of
which is proportional to at least a portion of said audio signal,
the improvement which comprises:
a light emitting diode as the light emitting source;
an external low voltage dc source for lighting said light emitting
diode connected thereto; and
means for modulating the current from said dc source to said light
emitting diode in response to said audio signal.
7. A method of adjusting the level of a plurality of speakers
controlled in a single console wherein each speaker has at least
one light emitting diode whose illumination is controlled by a
feedback impulse from the audio signal furnished to each of said
speakers, said method comprising:
setting the sound level for each speaker at the console;
observing the level of the sound at each speaker from the console
by viewing the response of the light emitting diode; and
adjusting the sound level of the speakers from the console until
the response of the light emitting diode at each speaker is the
same as that at each other speaker which will result in an equal
sound level being emitted from each speaker.
8. A method as claimed in claim 7 wherein each speaker includes a
plurality of light emitting diodes which are responsive to
different minimum sound levels and wherein said adjusting step
further includes:
adjusting the sound level of the speakers from the console until
the same number of light emitting diodes on each speaker are
lighted simultaneously at any one time so that an equal sound level
is emitted from each speaker.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an audio responsive light display
system characterized by one or more light emitting diodes powered
by a low voltage direct current source and modulated, for example,
by speaker feedback.
2. Description of the Prior Art
Light displays which fluctuate in intensity and/or color in
response to volume, range of frequency are well known. Reference
may be had to U.S. Pat. No. 1,790,903 to Craig wherein there is
provided in a radio speaker, colored electric lamps with numerous
switches adapted to be selectively sympathetically vibrated by the
sounds issuing from the speaker. Another device producing a color
effect from sound is shown in U.S. Pat. No. 1,946,026 to Lewis, et
al. Devices for producing projected optical effects are shown in
U.S. Pat. Nos. 3,473,428 to Phillips; 3,590,681 to Cross and
3,603,195 to Williams. Still another form utilizes a stroboscopic
lamp in combination with a rotary speaker as shown in U.S. Pat. No.
3,478,837 to Ross. A liquid crystal display is shown in U.S. Pat.
No. 3,623,392 to Boyer. Sharp in U.S. Pat. No. 3,719,857 teaches an
audio responsive intensity modulator for gas discharge lamps.
Goldschmied in U.S. Pat. No. 3,798,638 teaches an audio responsive
light display system using a speaker as a microphone, the output of
which is amplified and provided by a separate filter networks to a
plurality of lamp driver circuits and utilizes a novel alternating
current/battery power supply.
SUMMARY OF THE INVENTION
The simultaneous stimulation of more than one sense by a common
stimulant as a means of entertainment is enjoying new popularity
particularly in the audio-visual field where sound, e.g. music, is
the stimulant and both the senses of hearing and sight are acted on
by channeling the signal to both sound reproducing means and to
light actuating means. The present invention provides a simple,
inexpensive and effective means for achieving the foregoing
end.
Briefly stated, the present invention is in an audio responsive
light display system comprising in combination a speaker responsive
to an audio signal and productive of a feedback impulse, at least
one LED, and external low voltage dc source and means for
modulating the current flow from said dc source to said LED in
response to the feedback impulse. The present invention is
distinguished from such prior art that instead of utilizing a
filament gas discharge lamp, there is employed a light emitting
diode in combination with an external very low voltage direct
current source, i.e., less than 10 volts, and circuitry to modulate
the current flow in response to audio signals. The LED or LED's can
be powered by two 1.5 volt dry cells connected in series and with
very small current drain measured in microamps will last several
months and are thus adapted to be continuously at ready for
operation. Qualification according to certain standards, such as by
Underwriters Laboratories, is not required because the voltage is
so low. Moreover, since the power source is external to the
receiver/amplifier system, there is no degradation of the audio
signal due to noise as may be encountered in prior art devices
wherein light bulbs are operated from an ac source. Although the
LED's are desirably displayed on the speaker housings, they may as
well be separately displayed for other purposes, e.g., ready
identification of which speaker or speakers in an array are
operative.
With present day multiple track stereo systems multiple speakers
are used which are located in different parts of the room. These
speakers are separately controlled by console. In order to adjust
the volume level of the speakers it is necessary for the operator
to set the volume of one speaker from the console then walk over to
the speaker and listen to it. If the volume is not at the right
level he must then go back to the console, re-adjust the level and
go back to the speaker again. This can occur several times before
the speaker is properly adjusted. With multiple speakers the time
and effort in adjusting all of the speakers to the right volume is
greatly increased since the operator must walk from the console to
each speaker and back again until he gets the proper adjustment.
With the present invention, it is possible to visually observe the
speakers from the console and determine whether or not the volume
level is proper by observing the intensity of light emitted by the
LED's at each speaker.
Additional advantages will become apparent from a description which
follows, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood by having reference
to the annexed drawings wherein;
FIG. 1 is a perspective illustration of a speaker having several
LED's mounted in the front grille thereof;
FIG. 2 is a side view of a speaker in accordance with this
invention with the side cover panel removed to show the mounting of
the parts;
FIG. 3 is a circuit for modulating the current flow to LED from the
low voltage external dc source in response to an audio signal;
and
FIG. 4 is still another circuit illustrating a network for driving
a plurality of LED's.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with this invention there is shown in FIGS. 1 and 2 a
speaker housing 10 having a front grille 12 in which a plurality of
LED's 14 are supported in a vertical array. Alternatively, the
LED's may be arranged in a different array or only a single LED may
be used. However, the vertical array shown has a special
application as described below. With more particular reference to
FIG. 2, there is here shown a side view of a speaker such as that
shown in FIG. 1 with the side panel removed to expose the internal
arrangement of the parts. Accordingly, there is shown a cabinet
back panel 16, and a speaker mounting panel 18 having mounted
thereon in a conventional manner a speaker 20. Audio input lines 22
connect the speaker 20 to an audio input jack 24.
Ahead of the speaker mounting panel 18, is grille 12 in which a
plurality of LED's 14 are mounted on a printed circuit board 28
supported immediately behind the grille. An LED control line 30
electrically connects the printed circuit board 28 with a second
printed circuit board 32 mounted on the cabinet back panel 16 and
including a suitable circuit for controlling the LED's 14. A holder
34 mounted on the cabinet back panel 16 provides a suitable
recepticle for batteries 36 supported therein. Battery lead wires
38 communicate between the batteries 36 and the printed circuit
board 32. The speaker feed back or audio input is communicated to
the printed circuit board 32 by the lead lines 40.
FIG. 3 is illustrative of one circuit which may be embodied in the
printed circuit board 32 and utilized in carrying out the present
invention. This circuit for driving an LED represents a very
inexpensive and simple circuit for providing an audio responsive
light display utilizing an LED powered conveniently by dry cells
such as two 11/2 volt dry cells which are arranged in series to
provide a 3 volt output. This circuit, as illustrated, is for a
speaker having a single LED but as is readily apparent to one
skilled in the art can be extended for use with a multiple light
arrangement as shown in FIGS. 1 and 2.
As can be seen in FIG. 3, the feedback signal is fed into
transformer T1 at input jacks 24, as shown. For this particular
circuit, the following values have been found to be quite
satisfactory: C1 equals 0.22uf; C2 equals 1uf; C3 equals 10uf; R1
equals 10K ohms, R2 equals 2.2M ohms; R3 equals 51 ohms; R4 equals
270 ohms; R5 equals 6.8 ohms, All of these resistors are 1/2 watt
10 percent resistors; diodes D1, D2 and D3 are IN4004 diodes; Q1 is
a 2N3904 transistor and Q2 is a 2N3906 transistor. L1, is of course
a light emitting diode 14 whose response is controlled by the audio
input from jacks 24 which controls through this circuitry the flow
of current from battery 36 through light emitting diode 14.
In FIG. 4 a typical threshold circuit is shown wherein audio input
24 is provided to control a signal from an external dc circuit as
in FIG. 3 but wherein the base of each transistor is connected to
resistors of increasing value so that the number of LED's lighted
is proportional to the feedback input at input jacks 24. In other
words, in a vertical array of LED's, as shown in FIGS. 1 and 2, a
very low resistance may be associated with the bottom LED and these
resistances increase in value upwardly so that the number of LED's
lighted will be proportional to the volume of input sound. Thus,
when the sound is very loud all of the LED's will be lighted
whereas when the sound is at a lower level only a portion of them
will be lighted.
This arrangement is very convenient wherein a plurality of speakers
is placed around the room and are controlled from a console. The
operator can observe each speaker from the console and can tell the
level of audio output by the number of LED's which are lighted in
each speaker. Where speakers with a single light are provided the
same can be accomplished but not to a similar degree of accuracy.
In other words, by the brillance of the light of the LED and the
frequency with which it flickers the operator can by making a
visual comparison between the speakers in the room tell the
approximate relative audio level of all speakers.
From the foregoing, the advantages of this invention are readily
apparent. A system has been provided wherein the enjoyment of the
music listener can be increased by the visual sensation provided by
one or more LED's on a speaker grille being lighted by feedback
from the speaker. The LED's receive a signal from a low power dc
circuit which is external to the internal system and therefore does
not require Underwriters Laboratory approval. However, this
external circuit is controlled by the audio feedback from the
speaker through a transformer to control the lighting of the LED's
in response to this feedback. The result is a flickering of the
LED's as music or other sounds are being played over the speaker
system to enhance the enjoyment of the listener.
Furthermore, the LED's can be used to adjust the audio level of the
speakers, particularly where a plurality of speakers are placed
around a room and operated from a central console. By visually
observing any LED's the operator can adjust the volume of the
respective speakers to the desired level and adjust the sound
proportionately among the speakers as desired.
The invention has been described in detail with particular
reference to a preferred embodiment thereof, but it will be
understood that variations and modifications can be effected within
the spirit and scope of the invention.
* * * * *