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Claims  |
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What is claimed is:
1. A spoken-instruction controlled system for an automotive vehicle which
can activate an actuator in response to a predetermined spoken instruction
inputted through a microphone, which comprises:
(a) recognition switch for outputting a recognition switch signal when
closed;
(b) a speech recognizer responsive to said recognition switch signal for
outputting a command signal in response to the predetermined spoken
instruction inputted thereto through the microphone when said recognition
switch is first closed;
(c) means for holding the command signal from said speed recognizer for a
predetermined time period; and p1 (d) means responsive to said holding
means and said recognition switch signal for outputting an actuator signal
repeatedly when said recognition switch is closed repeatedly while said
holding means is holding the command signal.
2. A spoken-instruction controlled system for an automotive vehicle as set
forth in claim 1, wherein said holding means is a retriggerable
multivibrator which is first triggered by the command signal and then
retriggered when said recognition switch is closed.
3. A spoken-instruction controlled system for an automotive vehicle as set
forth in claim 1, wherein said actuator-signal outputting means is an AND
gate, an input terminal of which is connected to said recognition switch,
the other input terminal of which is connected to said holding means, and
the output terminal of which is connected to the actuator.
4. A spoken-instruction controlled system for an automotive vehicle which
can activate at least one actuator in response to at least one
predetermined spoken instruction inputted through a microphone, which
comprises:
(a) a recognition switch connected to a DC voltage V.sub.D and ground for
outputting a L-voltage level recognition switch signal e.sub.rs when
closed but a H-voltage level signal V.sub.D when opened;
(b) a two-circuit analog switch including a first switch unit and a second
switch unit and connected to said recognition switch and the DC voltage
V.sub.D, the first switch unit outputting a H-voltage level signal V.sub.D
when deactivated but a H- or L-voltage level signal V.sub.D or e.sub.rs
when activated, the second switch unit outputting a H- or L-voltage level
signal V.sub.D or e.sub.rs when deactivated but a H-voltage level signal
V.sub.D when activated;
(c) a speech recognizer connected to the second switch unit of said
two-circuit analog switch for outputting a first command signal e.sub.t
from a first output terminal 100a thereof in response to the first
predetermined spoken instruction and a second commnd signal e.sub.c from a
second output terminal 100b thereof in response to the second
predetermined spoken instruction both inputted through the microphone when
said recognition switch is kept closed for applying the L-voltage level
signal e.sub.rs thereto via the second switch unit of said two-circuit
analog switch only while said two-circuit analog switch is being
deactivated;
(d) an inverter connected to the first switch unit of said two-circuit
analog switch for inverting the signal e.sub.rs outputted from the first
switch unit and outputting a signal e.sub.rs ' corresponding thereto;
(e) a first analog switch connected to said inverter and the first output
terminal 100a of said speech recognizer for outputting the first command
signal e.sub.t when deactivated but the inverted recognition switch signal
e.sub.rs ' when activated;
(f) a first AND gate one input terminal of which is connected to said first
analog switch;
(g) a first retriggerable timer unit connected to said first AND gate for
outputting a H-voltage level timer signal e.sub.rt1 for a predetermined
time period when triggered in response to the first command signal e.sub.t
inputted via said deactivated first analog switch and said first AND gate
and when retriggered in response to the inverted recognition switch signal
e.sub.rs ' inputted via said activated first analog switch and said first
AND gate;
(h) a second analog switch connected to said inverter and the second output
terminal 100b of said speech recognizer for outputting the second command
signal e.sub.c when deactivated and the inverted recognition switch signal
e.sub.rs ' when activated;
(i) a second AND gate one input terminal of which is connected to said
second analog switch, the other inverted input terminal of which is
connected to said first retriggerable timer unit;
(j) a second retriggerable timer unit connected to said second AND gate,
the output terminal of which is connected the other inverted input
terminal of said first AND gate 24, for outputting a H-voltage level timer
signal e.sub.rt2 for a predetermined time period when triggered in
response to the second command signal e.sub.c inputted via said
deactivated second analog switch and said second AND gate and when
retriggered in response to the inverted recognition signal e.sub.rs '
inputted via said activated second analog switch and said second AND gate;
(k) an OR gate two input terminals of which are connected to said first and
second retriggerable timer units, respectively, for outputting a switch
control signal e.sub.s to said two-circuit analog switch and said first
and second analog switches to activate them when either of the two signals
e.sub.rt1 and e.sub.rt2 is inputted thereto;
(l) an NAND gate, one input terminal of which is connected to said inverter
and the other input terminal fo which is connected to said first
retriggerable timer unit for outputting a L-voltage level signal to an
actuator to activate it repeatedly when the inverted recognition signal
e.sub.rs ' and the timer signal e.sub.rt1 are both at a H-voltage level at
the same time; and
(m) a shift register the set terminal of which is connected to said
inverter and the reset terminal of which is connected to said second
retriggerable timer unit for outputting a H-voltage level signal
sequentially to a plurality of other actuators to activate them from each
of output terminals thereof whenever the inverted recognition switch
signal e.sub.rs ' is inputted to the set terminal thereof after reset in
response to the timer signal e.sub.rt2.
5. A spoken-instruction controlled system for an automotive vehicle as set
forth in claim 4, which further comprises:
(a) an OR gate, one input terminal of which is connected to said speech
recognizer for receiving the tuning command signal e.sub.t, the other
inverted input terminal of which is connected to the NAND gate for
receiving the first retriggerable timer signal e.sub.rt1 ; and
(b) a one-shot multivibrator connected to said OR gate for outputting a
tuning actuator signal e.sub.at for a predetermined time period when
triggered by one of the signal e.sub.t and the signal e.sub.rt1,
whereby the actuator can be activated by the tuning command signal e.sub.t
directly when a spoken instruction "Tuning" is first inputted to the
system through the microphone.
6. A spoken-instruction controlled system for an automotive vehicle which
can activate at least one actuator in response to at least one
predetermined spoken instruction inputted through a microphone, which
comprises:
(a) recognition switch for outputting a recognition switch signal e.sub.rs
when depressed; and
(b) a microcomputer including an analog-to-digital converter, a central
processing unit, a read-only memory, a random-access memory, an input
port, and an output port, said analog-to-digital converter of which is
connected to the bandpass filters, and said input port of which is
connected to said recognition switch, in response to the recognition
switch signal e.sub.rs said microcomputer outputting a command signal
e.sub.t corresponding to the spoken instruction transduced through said
microphone to be one of the actuators when said microcomputer determines
the transduced spoken instruction to be one of reference spoken
instruction previously stored therein, resetting a counting function in
said central processing unit to zero and incrementing the counting
function in response to the command signal e.sub.t, determining whether a
predetermined time period has elapsed, determining whether the recognition
switch signal e.sub.rs is inputted thereto if less than the predetermined
time period, standing-by the succeeding spoken instruction if more than
the predetermined time period, outputting an actuator signal e.sub.at if
the recognition switch signal e.sub.rs is inputted thereto within the
predetermined time period and then resetting the counting function to zero
again, and outputting no actuator signal if the recognition switch signal
e.sub.rs is not inputted thereto within the predetermined time period and
then incrementing the counting function again.
7. A spoken-instruction controlled system for an automotive vehicle as set
forth in claim 6, wherein said microcomputer further comprises the steps
of ORing the command signal e.sub.t and the inward actuator signal
e.sub.at and outputting a signal corresponding thereto for a predetermined
time period.
8. A spoken-instruction controlled system for an automotive vehicle as set
forth in claim 6, which further comprises a shift register, the set and
reset terminals of which are connected to said microcomputer and output
terminals of which are connected to a plurality of actuators,
respectively, said shift register being activated in response to the
command signal for a predetermined time period and shifted in response to
the recognition switch signal e.sub.rs for activating the actuators
sequentially.
9. A spoken-instruction controlled system for an automotive vehicle as set
forth in any of claims 1, 2, 3, 4, 5, 6, 7 or 8 wherein said recognition
switch is disposed by the side of an accelerator pedal.
10. A spoken-instruction controlled system for an automotive vehicle as set
forth in claim 9, wherein said recognition switch disposed by the side of
an accelerator pedal comprises:
(a) an elongated channel-shaped member with grooves in the opposing wall;
(b) an elastic member with a flange at the end thereof so dimensioned as to
be compressed to fit into said channel-shaped member and firmly engages
with the grooves of said channel-shaped member; and
(c) a pair of conductive ribbon contacts fixed to the flat surface of said
elastic member and to the inside elongate flat surface of said
channel-shaped member, respectively, with a space therebetween.
11. In a spoken-instruction controlled system for an automotive vehicle
which can activate at least one actuator in response to at least one
predetermined spoken instruction inputted through a microphone, the method
of actuating the actuator repeatedly, which comprises the following steps
of:
(a) generating a recognition switch signal e.sub.rs ;
(b) resetting the actuator in respnse to the recognition switch signal
e.sub.rs ;
(c) inputting a spoken instruction through the microphone while the
recognition switch signal e.sub.rs is being generated;
(d) recognizing the inputted spoken instruction as the one corresponding to
the actuator and outputting a command signal e.sub.t ;
(e) resetting a counter function to "0" in response to the signal e.sub.t ;
(f) incrementing the counter function;
(g) determining whether the counted value exceeds a predetermined time
period;
(h) if the counted value exceeds the predetermined time period, returning
to step (a) for standing-by the succeeding recognition switch signal
e.sub.rs ;
(i) if the counted value does not exceed the predetermined time period,
determining the recognition switch signal e.sub.rs is generated again;
(j) if generated again, activating the actuator repeatedly and returning to
step (e) for resetting the counter function to "0" again;
(k) if not generated again, returning to step (f) for incrementing the
counter function again.
12. In a spoken-instruction controlled system for an automotive vehicle
which can activate at least one actuator in response to at least one
predetermined spoken instruction inputted through a microphone, the method
of actuating a plurality of actuators sequentially, which comprises the
following steps of:
(a) generating a recognition switch signal e.sub.rs ;
(b) resetting a shift register in respnse to the recognition switch signal
e.sub.rs ;
(c) inputting a spoken instruction through the microphone while the
recognition switch signal e.sub.rs is being generated;
(d) recognizing the inputted spoken instruction as the one corresponding to
the actuators and outputting a command signal e.sub.t ;
(e) resetting a counter function to "0" in response to the signal e.sub.t ;
(f) incrementing the counter function;
(g) determining whether the counted value exceeds a predetermined time
period;
(h) if the counted value exceeds the predetermined time period, returning
to step (a) for standing-by the succeeding recognition switch signal
e.sub.rs ;
(i) if the counted value does not exceed the predetermined time period,
determining the recognition switch signal e.sub.rs is generated again;
(j) if generated again, shifting the shift register sequentially and
returning to step (e) for resetting the counter function to "0" again;
(k) if not generated again, returning to step (f) for incrementing the
counter function again. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a spoken-instruction controlled
system for an automotive vehicle, and more specifically to a system for an
automotive vehicle which can activate a single actuator repeatedly or
actuators sequentially by depressing a recognition switch repeatedly
within a predetermined time period after a spoken instruction has been
recognized by a speech recognizer.
2. Description of the Prior Art
Conventionally, there is a well-known speech recognizer which can activate
various actuators in response to human spoken instructions. When this
speech recognizer is mounted on an automotive vehicle, the car radio, for
instance, can be turned on or off in response to a driver's spoken
instruction such as "Car radio on" or "Car radio off". The speech
recognizer is very convenient because various spoken instructions can be
recognized in order to control various actuators, without depressing
switches; however, there are some problems involved in applying this
system to an automotive vehicle. For instance, when the speech recognizer
is used for automatically tuning a car radio to a preferable broadcasting
station or a preferable program in response to a spoken instruction, since
the automatic tuning operation stops at a first station to which a car
radio is first tuned, in order to select a preferable broadcasting station
or radio program it is usually necessary to utter the same spoken
instruction repeatedly and additionally depress the recognition switch
repeatedly. These are very troublesome for the driver.
On the stepwise operations as described above, there are various cases such
as adjustment of remote-controlled fender mirrors, presetting of fan
speeds in an airconditioning system, adjustment of passenger compartment
air temperature in the airconditioning system, opening or closing of door
windows in a power-operated window system, etc.
Furthermore, in the prior-art speech recognizer, the recognition switch is
usually depressed by the hand; however, since the recognition switch
should be depressed repeatedly in the case of the speech recognizer of
this kind as described above, it is also important to select the position
at which the switch is disposed.
A more detailed description of a typical speech recognizer will be made
with reference to the attached drawing in conjunction with the present
invention under DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS.
SUMMARY OF THE INVENTION
With these problems in mind therefore, it is the primary object of the
present invention to provide a spoken-instruction controlled system for an
automotive vehicle whereby a single actuator can be activated repeatedly
or a plurality of actuators can be activated sequentially by depressing
only a recognition switch repeatedly within a predetermined time period
after a spoken instruction corresponding to the single actuator or a
plurality of actuators has been recognized by a speech recognizer, without
uttering the same spoken instruction repeatedly.
Further, it is the other object of the present invention to provide a
recognition switch which can be depressed by a driver's foot easily,
without using the hand.
To achieve the above-mentioned object, the spoken-instruction controlled
system for an automotive vehicle according to the present invention
comprises a recognition switch depressed when a spoken instruction is
inputted to the system and an actuator is activated repeatedly or
actuators are activated sequentially, a two-circuit analog switch for
switching the recognition switch signal, at least one analog switch for
switching a command signal outputted from a speech recognizer to the
recognition switch signal or vice versa, at least one retriggerable timer
unit for outputting a switch control signal to be applied to the
two-circuit analog switch and the analog switch for a predetermined time
period, an inverter, an AND or NAND gate, an OR gate, a shift register
etc., in addition to a speech recognizer.
To achieve the above-mentioned other object, the recognition switch
according to the present invention comprises an elongated channel-shaped
member with grooves in the opposing wall, an elastic member with a flange
at the end, and a pair of conductive ribbon contacts. Further, the
recognition switch according to the present invention is disposed by the
side of an accelerator pedal.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the spoken-instruction controlled system for
an automotive vehicle according to the present invention will be more
clearly appreciated from the following description taken in conjunction
with the accompanying drawings in which like reference numerals designate
corresponding elements or sections throughout the drawings and in which;
FIG. 1 is a schematic block diagram of a typical speech recognizer for
assistance in explaining the operations thereof;
FIG. 2 is a fragmentary schematic block diagram of an essential portion of
a first embodiment of the spoken-instruction controlled system for an
automotive vehicle according to the present invention;
FIG. 3 is a timing chart of the first embodiment of the spoken-instruction
controlled system for an automotive vehicle according to the present
invention;
FIG. 4 is a schematic block diagram of a second embodiment of the
spoken-instruction controlled system for an automotive vehicle according
to the present invention, in which a microcomputer is included;
FIG. 5 is a flowchart showing the method of repeatedly activating the same
actuator and sequentially activating a plurality of actuators in response
to a spoken instruction in accordance with programs stored in the
microcomputer shown in FIG. 4;
FIG. 6 is a perspective pictorial view showing the position at which the
recognition switch according to the present invention is disposed;
FIG. 7(A) is a front view showing the recognition switch according to the
present invention; and
FIG. 7(B) is a cross-sectional view of the recognition switch according to
the present invention, taken along the line B--B of FIG. 7(A).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
To facilitate understanding of the present invention, a brief reference
will be made to the principle or operation of a typical prior-art speech
recognizer, with reference to FIG. 1.
FIG. 1 shows a schematic block diagram of a typical speech recognizer 100.
To use the speech recognizer, the user must first record a plurality of
predetermined spoken instructions. Specifically, in this spoken
instruction recording mode (reference mode), the user first depresses a
record switch 1 disposed near the user. When the record switch 1 is
depressed, a switch input interface 4 detects the depression of the record
switch 2 and outputs a signal to a controller 5 via a wire 4a. In response
to this signal, the controller 5 outputs a recording mode command signal
to other sections in order to preset the entire speech recognizer to the
recording mode. In the spoken instruction recording mode, when the user
says a phrase to be used as a spoken instruction, such as "Car radio on",
near a microphone 2, the spoken phrase is transduced into a corresponding
electric signal through the microphone 2, amplified through a speech input
interface 6 consisting mainly of a spectrum-normalizing amplifier,
smoothed through a root-mean-square (RMS) smoother 15 including a
rectifier and a smoother, and finally inputted to a voice detector 7. This
voice detector 7 detects whether or not the magnitude of the spoken phrase
signals exceeds a predetermined level for a predetermined period of time
(150 to 250 ms) in order to determine the start of the spoken phrase input
signals and whether or not the magnitude of the signals drops below a
predetermined level for a predetermined period of time in order to
determine the end of the signals. Upon detection of the start of the
signals, this voice detector 7 outputs another recording mode command
signal to the controller 5. In response to this command signal, the
controller 5 activates a group of bandpass filters 8, so that the spoken
phrase signal from the microphone 2 is divided into a number of
predetermined frequency bands. Given to a parameter extraction section 9,
the frequency-divided spoken phrase signals are squared or rectified
therein in order to derive the voice power spectrum for each of the
frequency bands and then converted into corresponding digital time-series
matrix-phonetic pattern data (explained later). These data are then stored
in a memory unit 10. In this case, however, since the speech recognizer is
set to the spoken instruction recording mode by the depression of the
record switch 1, the time-series matrix-phonetic pattern data are
transferred to a reference pattern memory unit 11 and stored therein as
reference data for use in recognizing the speech instructions.
After having recorded the reference spoken instructions, the user can input
speech instructions, such as "Car radio on", to the speech recognizer
through the microphone 2 while depressing a recognition switch 3.
When this recognition switch 3 is depressed, the switch input interface 4
detects the depression of the recognition switch 3 and outputs a signal to
the controller 5 via a wire 4b. In response to this signal, the controller
5 outputs a recognition mode command signal to other sections in order to
preset the entire speech recognizer to the recognition mode. In this
spoken phrase recognition mode, when the user says an instruction phrase
similar to the one recorded previously near the microphone 2 and when the
voice detector 7 outputs a signal, the spoken instruction is transduced
into a corresponding electric signal through the microphone 2, amplified
through the speech input interface 6, filtered and divided into voice
power spectra across the frequency bands through the band pass filters 8,
squared or rectified and further converted into corresponding digital
time-series matrix-phonetic pattern data through the parameter extraction
section 9, and then stored in the memory unit 10, in the same manner as in
the recording mode.
Next, the time-series matrix-phonetic pattern data stored in the memory
unit 10 in the recognition mode are sequentially compared with the
time-series matrix-phonetic pattern data stored in the reference pattern
memory unit 11 in the recording mode by a resemblance comparator 12. The
resemblance comparator 12 calculates the level of correlation of the
inputted speech instruction to the reference speech instruction after time
normalization and level normalization to compensate for variable speaking
rate (because the same person might speak quickly and loudly at one time
but slowly and in a whisper at some other time). The correlation factor is
usually obtained by calculating the Tchebycheff distance (explained later)
between recognition-mode time-series matrix-phonetic pattern data and
recording-mode time-series matrix-phonetic pattern data. The correlation
factor calculated by the resemblance comparator 12 is next given to a
resemblance determination section 13 to determine whether or not the
calculated values lie within a predetermined range, that is, to evaluate
their cross-correlation. If within the range, a command signal, indicating
that a recognition-mode spoken instruction having adequate resemblance to
one of the recorded instruction phrases, is outputted to one of actuators
14 in order to turn on the car radio, for instance. The abovementioned
operations are all executed in accordance with command signals outputted
from the controller 5.
Description has been made hereinabove of the case where the speech
recognizer 100 comprises various discrete elements or sections; however,
it is of course possible to embody the speech recognizer 100 with a
microcomputer including a central processing unit, a read-only memory, a
random-access memory, a clock oscillator, etc. In this case, the voice
detector 7, the parameter extraction section 9, the memory 10, the
reference pattern memory 11, the resemblance comparator 12 and the
resemblance determination section 13 can all be incorporated within the
microcomputer, executing the same or similar processes, calculations
and/or operations as explained hereinabove.
The digital time-series matrix-phonetic pattern data and the Tchebycheff
distance are defined as follows:
In the case where the number of the bandpass filters is four and the number
of time-series increments for each is 32, the digital recording-mode time
series matrix-phonetic pattern data can be expressed as
##EQU1##
where A designates a first recording-mode speech instruction (reference)
(e.g. CAR RADIO ON), i denotes the filter index, and j denotes time-series
increment index.
If a first recognition-mode speech instruction (e.g. CAR RADIO ON) is
denoted by the character "B", the Tchebycheff distance can be obtained
from the following expression:
##EQU2##
In the speech recognizer 100 of FIG. 1, when the actuator 14 is used for
tuning a car radio to a preferable broadcasting station or program, since
the operation of the automatic tuning stops at the first station to which
a car radio is first tuned, in order to select a preferable broadcasting
station or a preferable radio program from a plurality of stations or
programs, the driver must utter the same spoken instruction repeatedly and
additionally depress the recognition switch repeatedly.
Further, when a plurality of actuators 14 are used for selecting the car
radio channels to which predetermined broadcasting stations have already
been set, since the operation of the automatic channel selection stops at
the first channel, in order to select a preferable channel, that is, a
preferable station, the driver must utter the same spoken instruction
releatedly and additionally depress the recognition switch repeatedly.
In view of the above description and with reference to the attached
drawings, a first embodiment of the present invention will be explained
with respect to its application to an automatic tuning operation and an
automatic channel selecting operation in a car radio. In this connection,
in the case of an automatic tuning operation, the station tuning operation
stops at a first tuned broadcasting station while sweeping from the lower
frequency to the higher frequency, when the corresponding spoken
instruction is inputted to the system, whereas in the case of an automatic
channel selecting operation, the channel selecting operation stops at the
next channel to which a broadcasting frequency has previously set, when
the corresponding spoken instruction is inputted to the system.
In FIG. 2, the reference numeral 100 denotes a speech recognizer to which
spoken instructions are inputted through a microphone for transducing a
spoken phrase into the corresponding electric signal. When recognizing the
inputted spoken phrase as a predetermined spoken instruction, the speech
recognizer 100 outputs a command signal corresponding to the spoken
instruction, as already described hereinabove. In this embodiment, since a
car radio 14 (actuator) is controlled by the spoken-instruction controlled
system, when a spoken instruction "Tuning" is recognized for automatic
broadcasting station tuning operation, the output terminal 100a of the
speech recognizer 100 outputs a H-voltage level tuning command signal
e.sub.t ; when a spoken instruction "Channel" is recognized for automatic
channel selecting operation, the output terminal 100b thereof outputs a
H-voltage level channel command signal e.sub.c.
The reference numeral 3 denotes a push-button type recognition switch for
outputting a recognition switch signal e.sub.rs, which is depressed when a
spoken instruction is given to the system. To one terminal of the switch
3, a voltage is applied by dividing a power supply voltage (+V.sub.D) with
two resistors R.sub.1 and R.sub.2. Further, a Zener diode ZD is connected
in parallel with the resistor R.sub.2 in order to absorb the surge
voltages due to contact chattering caused when the push-botton switch 3 is
depressed. While this push-botton switch 3 is off (released), the
potential at point A is at a H-voltage level determined by the two
division resistors R.sub.1 and R.sub.2 ; while this push-botton switch is
on (depressed), the potential at point A is at a L-voltage level
(grounded).
The reference numeral 16 denotes a two-circuit analog switch including a
first switch unit 16-1 and a second switch unit 16-2 provided with a
movable contact a and two fixed contacts b and c each. When a switch
control signal e.sub.s is at a L-voltage level, this analog switch 16 is
deactivated and set as shown by solid lines in FIG. 2 with the movable
contacts a in contact with the fixed contacts b respectively. In this
state, accordingly, the potential at point B of the first switch unit 16-1
is at a H-voltage level determined by the supply voltage (+V.sub.D) given
via a resistor R.sub.3 ; the potential at point C of the second switch
unit 16-2 is at the same voltage level as at point A (H if 3 is off, L if
3 is on). On the other hand, when the switch control signal e.sub.s
changes to a H-voltage level, this analog switch 16 is activated and set
as shown by broken lines in FIG. 2 with the movable contacts a brought
into contact with the other fixed contacts c respectively. In this state,
accordingly, the potential at point B of the first switch unit 16-1
changes to the same voltage level as at point A (H if 3 is off, L if 3 is
on); the potential at point C of the second switch unit 16-2 changes to
the same H-voltage level determined by the supply voltage (+V.sub.D).
Further, in this embodiment, since the potential at point C of the second
switch unit 16-2 is applied to the speech recognizer 100, the speech
recognizer 100 is activated in response to the L-voltage level signal
e.sub.rs but deactivated in response to the H-voltage level. In more
detail, if the switch control signal e.sub.s is at the L-voltage level,
only when the recognition push-button switch 3 is kept depressed, the
speech recognizer 100 is operative; however, if the switch control signal
e.sub.s is at the H-voltage level, the speech recognizer 100 is
inoperative, regardless of the depression or release of the recognition
push-button switch 3.
The reference numeral 17-1 denotes a first analog switch and the reference
numeral 17-2 denotes a second analog switch. The analog switch 17-1 or
17-2 is provided with a movable contact a and two fixed contacts b and c.
When the switch control signal e.sub.s is at a L-voltage level, these
analog switches 17-1 and 17-2 are set as shown by solid lines in FIG. 2
with the movable contacts a in contact with the fixed contacts b
respectively. In this state, accordingly, the potential at point D of the
first analog switch 17-1 is at a H-voltage level e.sub.t only when a
spoken instruction "Tuning" is recognized; the potential at point E of the
second analog switch 17-2 is at a H-voltage level e.sub.c only when a
spoken instruction "Channel" is recognized. On the other hand, when the
switch control signal e.sub.s changes to a H-voltage level, these analog
switches 17-1 and 17-2 are set as shown by broken lines in FIG. 2 with the
movable contacts a brought into contact with the other fixed contacts c
respectively. In this state, accordingly, the potentials at point D and E
of the first and second analog switches 17-1 and 17-2 change to a
L-voltage level e.sub.rs ' when the push-button switch 3 is off but a
H-voltage level when the push-button switch 3 is on, because an inverter
is connected between the first two-circuit analog switch 16 and the first
or second analog switch 17-1 or 17-2.
The reference numeral 20-1 denotes a first retriggerable timer unit and the
reference numeral 20-2 denotes a second triggerable timer unit. The
retriggerable timer unit outputs a H-voltage level signal e.sub.rt1 or
e.sub.rt2 for a predetermined time period when the input terminal thereof
changes from a L-voltage level to a H-voltage level. Further, this
retriggerable timer unit can be retriggered when a H-voltage level signal
is applied thereto even after having been triggered, that is, even while
outputting a H-voltage level signal. When retriggered, the timer unit
keeps outputting again the H-voltage level signal for the predetermined
time period beginning from the time when retriggered.
The reference numeral 21 denotes a shift register, which is reset
(inoperative) when a L-voltage level signal is applied to the reset
terminal thereof, but set (operative) when a H-voltage level signal is
applied to the reset terminal thereof. When set (operative), the shift
register 21 outputs a H-voltage level signal sequentially from the output
terminals Q.sub.1 to Q.sub.5 in response to a H-voltage level signal
inputted to the set terminal thereof. In more detail, when the second
timer 20-2 outputs a H-voltage level signal to set (operative) the shift
register 21 and when the switch control signal e.sub.s is developed, the
register 21 outputs H-voltage level signals in sequential order from the
output terminals Q.sub.1 to Q.sub.5 in response to the signals from the
recognition switch 3.
The reference numerals 21a to 21e denote inverters for inverting the output
signal e.sub.ac from the shift register 21. The output terminals of these
inverters 21a to 21e are connected to the channel-selection lines of the
car radio 14. If the inverter output signal is at a H-voltage level, the
channel selection is inhibited; if at a L-voltage level, the channel
selection is operated according to the output line at which the signal
level changes from a H-voltage level to a L-voltage level.
Although, the channel selection is operated on in response to a L-voltage
level signal in this embodiment; however, it is of course possible to
activate the channel selecting actuators in response to a H-voltage level
signal. In such case, the inverters 21a-21e are unnecessary.
The reference numeral 22 denotes a NAND gate, one input terminal of which
is connected to the inverter 18, the other input terminal is connected to
the first timer 20-1 and the output terminal of which is connected to the
frequency tuning line of the car radio 14. If the NAND gate output signal
is at a H-voltage level, the automatic tuning is inhibited; if at a
L-voltage level, the automatic tuning is operated.
The reference numeral 23 denotes an OR gate, one input terminal of which is
connected to the first retriggerable timer 20-1 and the other input
terminal of which is connected to the second retriggerable timer 20-2 in
order to output the switch control signal e.sub.s to the two-circuit
analog switch 16 and the first and second analog switches 17-1 and 17-2.
Furthermore, the reference numerals 24 and 25 denote a first AND gate and a
second AND gate, respectively.
Now, the operations of the first embodiment shown in FIG. 2 will be
described hereinbelow with reference to the timing chart shown in FIG. 3.
First, the case is explained when automatic tuning operation is performed
in accordance with a spoken instruction.
When the recognition switch 3 is depressed at time t.sub.1, the output of
the switch 3 (point A) changes to a L-voltage level. Therefore, the
L-voltage level signal e.sub.rs is applied to the speech recognizer 100
via the second switch unit 16-2 of the two-circuit analog switch 16 to
keep the speech recognizer 100 operative. In this state (with the switch 3
kept depressed), when a spoken instruction, for instance, "Tuning" is
inputted through the microphone 2, this spoken instruction is recognized
by the speech recognizer 100, so that the output terminal 100a is kept at
a H-voltage level for a predetermined time period T.sub.o after a delay
time T.sub.D (some time interval is necessary to detect the start of the
spoken instruction). This H-voltage level tuning command signal e.sub.t
from the output terminal 100a of the speech recognizer 100 is applied to
one input terminal of the first AND gate 24 via the first analog switch
17-1. Since the other inverted input terminal of the AND gate 24 is also
at a H-voltage level because the second retriggerable timer unit 20-2 is
still kept inoperative with the output terminal at a L-voltage level, the
first AND gate 24 outputs a H-voltage level signal to the first
retriggerable timer unit 20-1, so that the timer unit 20-1 outputs a
H-voltage level signal e.sub.rt1 for a predetermined time period. Given to
one input terminal of the NAND gate 22 and to one input terminal of the OR
gate 23, this H-voltage level signal e.sub.rt1 from the first timer unit
20-1 becomes the switch control signal e.sub.s ; as a result, the
two-circuit analog switch 16 and the first and second analog switches 17-1
and 17-2 are all switched as shown by broken lines in FIG. 2. At this
time, since the recognition switch 3 has already been released, a
H-voltage level signal is given from the power supply +V.sub.D to the
inverter 18; that is, the output signal (e.sub.rs ') of the inverter 18 is
at a L-voltage level. In the NAND gate 22, since one input terminal is at
a L-voltage level (e.sub.rs ' from the inverter 18) and the other input
terminal is at a H-voltage level (e.sub.rt1 from the first retriggerable
timer 20-1), the output terminal thereof is at a H-voltage level e.sub.at,
so that the automatic tuning is inhibited. Further, in this state, since a
H-voltage level signal is applied from the power supply +V.sub.D to the
speech recognizer 100, the speech recognizer 100 becomes inoperative.
Furthermore, in this state, since the second analog switch 17-2 has been
switched as shown by broken lines by the switch control signal e.sub.s,
the L-voltage level output signal e.sub.rs ' from the inverter 18 is
applied to one of two input terminals of the second AND gate 25 in order
to prevent the second retriggerable timer unit 20-2 from being activated
(while the first timer unit 20-1 is H, the other inverted input terminal
of the AND gate 25 is L).
Next, when the recognition switch 3 is depressed again at time t.sub.2
while the first retriggerasble timer unit 20-1 is outputting a H-voltage
level signal e.sub.rt1 for a predetermined time period after being
activated by the command signal e.sub.t from the output terminal 100a, the
L-voltage level signal e.sub.rs from the recognition switch 3 is inverted
by the inverter 18, and the inverted H-voltage level signal e.sub.rs ' is
given to one input terminal of the NAND gate 22 and to one input terminal
of the first AND gate 24. Similarly to the case when the output terminal
100a of the speech recognizer 100 is at a H-voltage level, the first
retriggerable timer unit 20-1 is retriggered at time t.sub.2 in order to
output a H-voltage level signal e.sub.rt1 for the predetermined time
period beginning from when retriggered. Further, in this case, although
the H-voltage level signal e.sub.rs ' is also given to one input terminal
of the second AND gate 25, since the other inverted input terminal thereof
is at a L-voltage level (a H-voltage level first timer signal e.sub.rt1 is
inverted), the second retriggerable timer unit 20-2 is not activated. As a
result, two H-voltage level signals e.sub.rs ' and e.sub.rt1 from the
inverter 18 and the first timer unit 20-1 are applied to the two input
terminals of the NAND gate 22, respectively and thereby the output
terminal of the NAND gate 22 changes to a L-voltage level, outputting an
actuator signal e.sub.at for automatic tuning. In response to this
actuator signal e.sub.at, an electronic tuning device starts tuning by
sweeping and stops at the first tuned broadcasting station. If the program
of a broadcasting station thus tuned is not preferable, it is possible to
perform the automatic tuning operation again by depressing the recognition
switch 3 repeatedly within the predetermined time period during which the
first retriggerable timer unit 20-1 is kept at a H-voltage level, in the
same way as when the recognition switch 3 is depressed at time t.sub.2.
Therefore, the output terminal of the NAND gate 22 is changed to a
L-voltage level only while the recognition switch 3 is kept depressed in
order to perform the succeeding automatic tuning operation.
To explain in short, when the switch 3 is first depressed, point A
(e.sub.rs) is L; the speech recognizer 100 becomes operative. When
"Tuning" is inputted, the tuning command signal e.sub.t activates the
first timer 20-1 to output a timer signal e.sub.rt1. As a result, the
switch control signal e.sub.s switches all the analog switches 16, 17-1,
and 17-2 as shown by broken lines. At this moment, since the recognition
switch 3 has already been released to H, the inverter 18 (e.sub.rs ') is
L; the first timer 20-1 (e.sub.rt1) is still H; the NAND gate 22
(e | | |
