Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a procedure in
which the brightness of signalling and the volume of sound
signals are controlled on the basis of the background light
and the noise in the environment.
In many buildings, there are considerable
variations in the background lighting and noise, so that
conventional signal devices may not be seen or heard, or
else their excessive brightnesslloudness may disturb the
activities in the building. For example, in hospitals and
hotels, where activities go on day and night, the noise and
illuminance vary greatly at different times of the day.
Depending on the situation, different levels of brightness
and sound volume of the signal devices are required on
different floors. In some cases, additional lamps have to
be installed in poorly illuminated spaces to improve
visibility.
An object of the present invention is to
substantially overcome the present drawbacks, and thereby
to achieve a considerable improvement in the convenience
of, for example, use of an elevator. The invention also
aims at a simple and low-cost solution.
According to an aspect of the present invention,
there is provided a procedure for controlling the
brightness and sound volume of the signalling of the signal
devices of an elevator on the basis of the background
illuminance and the noise in the environment, respectively,
wherein the loudness of the background noise and the
intensity of the background illuminance are measured before
the signalling, and the values obtained are compared with
predetermined reference values on the basis of which the
brightness and sound volume of the signalling are adjusted
to suitable values by respective volume and brightness
control units.
In the procedure of the invention, the signal
sound volume is controlled by measuring the background
noise level before the signalling. When the background
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noise level is high, the sound signal is issued with a
higher volume, and similarly, when the background noise
level is low, the sound signal is issued with a lower
volume. The signal obtained from a noise level measuring
amplifier can be used directly for the volume control of
the audio signal to be issued. It is important that the
result of the background noise measurement be "locked"
before signalling, to ensure that the signalling itself
will not produce a change in the measured background noise
level. A brightness range, or certain possible brightness
values, may be defined in advance and stored in a control
unit, which adjusts the brightness of a signal on the basis
of the measurement result.
A volume control unit measures the intensity of
the background noise before the signalling, and if the
background noise level is high, the sound signal is issued
with a higher volume, and similarly, when the background
noise level is low, the sound signal is issued with a lower
volume. The measurement result is produced by a noise
level measuring unit.
The procedure of the invention has the advantages
that it:
involves no significant additional costs;
can be implemented using a few additional
components;
requires no separate attenuating resistors,
switches of wiring for day/night signalling;
can also be implemented as a system controlled
automatically according to the time of the day;
allows the use of other signalling devices, such
as texts, arrows and numbers;
achieves a considerable improvement in the
convenience of use of the elevator; and
is a most workable system in hospitals and
hotels.
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207~36~
In the following, the invention is described in
detail by the aid of an example by referrinq to the
attached drawing, which is a schematic illustration of a
signalling device for implementing the procedure of the
invention. The illustrated signalling device can be
installed separately on each floor of a building, and
operate independently according to the prevailing external
circumstances on the respective floor.
The drawing shows a signal device control unit in
which the brightness of signalling and the volume of sound
signals are controlled on the basis of the background light
and the noise in the environment. The control unit 1
controls signal devices 8, such as direction arrows and
floor indicators, by means of signalling control signals 11
via a brightness control amplifier 5. The brightness of
the light signals given by the signal devices 8 is
controlled by the brightness control amplifier 5 by means
of a light sensor 2, an illuminance measuring amplifier 4
and a control range level signal 12.
When the background illuminance increases, the
output voltage of the illuminance measuring unit 4 rises,
producing a larger signal at the output of the brightness
control amplifier 5 and a brighter light signal level of
the signal devices 8. Similarly, when the background
illuminance decreases, the brightness of the light signal
issued by the signal device 8 diminishes. A preset
signalling control range level 12 determining the range of
brightness variation of the signalling may be stored in the
control unit 1.
The background noise is measured by means of the
loudspeaker 3 of the sound signal device. The loudspeaker
3 reacts to background noise like a microphone, i.e. it
provides a signal proportional to the noise. The signal
obtained from the loudspeaker 3 is passed to a measuring
amplifier 7, whose output is applied to the input of a
variable-gain amplifier 6. Before the signalling, the
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control unit 1 "locks" the result of the noise level
measurement by means of a locking signal 9 to ensure that
the signalling itself will not produce a change in the
measured background noise level. When the control unit 1
performs the signalling by means of an audio signal lo, the
audio control amplifier 6 amplifies the audio signal
according to the locked background noise level and a preset
sound control range level 13. The signal at the output of
the audio control amplifier 6 is the larger the higher is
lo the locked noise level.
In an alternative embodiment, the adjustment of
the brightness of the signalling and the volume of the
audio signal is performed in the control unit 1, in which
case the output signals of the measuring amplifiers 4 and
7 are passed to the control unit 1.
It will be apparent to a person skilled in the
art that different embodiments of the invention are not
restricted to the examples described above, but that they
may instead be varied within the scope of the following
claims.
