Note: Descriptions are shown in the official language in which they were submitted.
~a6ao3~2
sackground of the Invention
_ _
This is a divisional of Canadian Patent Application No.
367,282, filed December l9th, 1980.
1. Field of the Invention:
The present invention relates to a heating apparatus which
can be controlled by voice command rather than by the pushing
many switch buttons.
2. Prior Art:
In a heating apparatus, a heating sequence or an object to
be heated must be defined before the start of a heating
operation. For example, to defrost frozen meat in an electronic
oven, it is desirable to heat for 30 minutes using a low power of
about 250 ~ as a first step, then stop heating about 30 minutes
as a second step to allow time ~or the temperature of the meat
become uniform. ~s a final third stage, the defrosted meat is
heated with a high output power of about 700 W for 10 minutes.
Such a complex heating sequence is in conventional apparatus
preset by keyboard entries, namely by pushing an output power
selecting key and a time key alternately. Therefore keying
operation becomes comparatively complex, and sometimes a user
must input the heating sequence again when the entered data is ~n
error, or when the object is overheated when the user is not
aware of a malfunction.
Generally speaking, when the user operates the heating
apparatus to heat some foods, the user's hand is sometimes wet or
oily etc. from food preparation. Since the user must touch the
operating panel of the apparatus the panel may become oily or
wet. Tllis enhances the probability that a user may get an
'~
electrical ~hock.
One effort to overcome such disadvantages, provided an
- la -
automatic electric oven of the card reader type which reads a
cooking card comprising a magnetic band preliminarily written
with a heating sequence. However, the electric oven of such type
sometimes misreads the cooking card that had become stained or
wet. Also if the user lost a cooking card it was not possible to
use that heating sequence. Therefore, the card reader type was
not satisfactory.
In recent years, attempts have been made to introduce
recorded voice, letters or words, signs or picture as an aid or
guide of communicating input commands into electronics systems,
in order to attain easier and more natural interaction between
the user and the apparatus. Especially, the use of voice is
attracting much attention as a most natural communication medium
between man and machine, and the use of the voice in the
apparatus becomes more and more practical as semi-conductor
technology develops to provide increasing speeds and increases of
memory capacity through higher integrations in the device, and
through appearance of microcomputers used as controlling units,
etc.
2~ The present invention provides a heating apparatus
controlled by means of voice recognition technology. Applicants
recognize that the present state of the art of voice recognition
does not always provide a perfectly accurate result even though
the number of users is limited, and therefore, they provide not
only an improvement in the voice recognition system hardware, but
also provides an overall arrangement providing enhanced safe
operation so as to prevent fatal accidents such as may result
from overheating due to misrecognition by the voice recognition
~16~L~
circuit. That is, since the heating apparatus includes an
electric heater or a microwave heating system, when an erroneous
operation of the apparatus without a load therein (object to be
heated) is carried out, then an enclosure case or a door of the
apparatus becomes heated to a high temperature, thereby causing a
liability of burning on the user's hand or further a fire, or at
least a damaging of the enclosure case or door or microwave
oscillator, heater or other elements.
Summary of the Invention
In one aspect the présent invention provides a heating
apparatus, such as an electronic oven, an ordinary electric oven
or a gas oven, capable of being controlled in response to
everyday language or words instead of touching of keys on the
operating panel thereof in order to eliminate the abovementioned
disadvantages. In the heating apparatus, some heating sequences
are preliminarily set in the apparatus and the user can select
one of them by a voice command. The heating apparatus operates
only when voice commands are applied to the apparatus in a
predetermined order, thereby preventing undesirable erroneous
oparation from ambient noise.
The heating apparatus in accordance with the present
invention can perform as follows:
The heating apparatus has a plurality of preliminarily
stored heating sequences corresponding to a kind of cooking or
materials, and selects one of them by a voice command, thereby a
complex switch operation to set the heating sequence can be
eliminated.
When the apparatus recognlzes user's voice commands, the
apparatus displays the result of recognition so that user can
conEorm the user's voice command.
The heating apparatus operates only when at least two
sequential voice commands in a scheduled order are applied,
thereby a malfunction of the apparatus by ambient noise can be
effectively reduced. As an added safety feature, certain
instructions require the apparatus to demand confirmation such as
for example, a "start of heating" command. After a "start of
heating" command the apparatus requests that the user make an
additional voice command to confirm it, thereby the safety in the
automatic operation is improved.
Brief Description of the Drawings
FIGURE 1 is a perspective view of a heating apparatus
embodying the present invention.
FIGURE 2 is an elevation view of a front panel of the
hea~ing apparatus of FIGURE 1.
FIGURE 3 is a circuit diagram of an example of the present
invention.
FIGURE 4 is a list of standard instructions of voice
commands and the recognition codes thereof.
FIGURE 5(a) is a central sectional view of one example of
the heating apparatus of the present invention.
FIGURE 5(b) is a graph of humidity change with respect to
the heating time.
FIGURE 6 is a circuit block diagram of the embodiment.
FIGURE 7 is a circuit diagram of an example of a filter bank
of the embodiment.
FIGURE 8 is a frequency characteristic graph oE bandpass
filters oE the filter bank oE FIGURE 7.
FIGURE 9 is a frequency characteristic graph of a low pass
filter of the filter bank of FIGURE 7.
FIGUREs lO(a), lO(b) and lO~c) are frequency characteristic
graphs o various part of the filter bank.
FIGURE ll is a circuit diagram of an analog multiplexer and
an A/D converter.
FIGURE 12 is a detailed circuit block of a recognition
circuit 63 and a control circuit 24 of the block diagram of
FIGURE 6.
FIGURE 13 is a circuit o an output block part of the
present invention.
FIGURE 14 is a memory map of memories of the embodirnent.
Description of the Preferred Embodiment
A heating apparatus comprising:
(a) an enclosure case having therein a heating chamber in
which an object to be heated is to be placed/ the enclosure case
having a door at an opening of said heating chamber,
(b) a heating means for radiating heating energy into said
heating chamber,
(c) detecting means for measuring physical data of heating
conditions of said object,
(d) a speech recognition and control circuit, and
(e) a displ~y means for displaying operation states of said
heating apparatust
wherein said speech recognition and control circuit
comprises:
(f) a voice command input means including a microphone for
transforming a user's voice commands into command input signals,
(g) a pattern analyzer Eor frequency-analyzing said command
input signals to divide them into input pattern signals each
associated with a predetermined frequency band, subsequently
sampling said input pattern signals and carrying out A/D
conversion ~hereof to produce pattern-analyzed digital data,
(h) an input pattern memory for memorizing said
pattern-analyzed digital data in a form of time sequential
patterns,
(i) a reference pattern memory for storing time sequential
reference pattern data as reference patterns,
(j) a recognition processing circuit for comparing said
pattern-analyzed digital data stored in said input pattern memory
with said time sequential reference pattern data stored in said
reference pattern memory, and for generating a signal indicative
of an affinity degree of the comparison, and for producing
predetermined recognition codes corresponding to recognized voice
cornmands, when said signal of said affinity degree ~or one
respective voice command among said user's voice commands is more
than a present signal level,
(k) a control circuit part including a program memory in
which a plurality of heating sequences are preliminarily stored
prior to the operation of said heating apparatus, and for
selecting and presetting the selected one of said heating
sequences based on said predetermined recognition codes, and for
controlling operations oE said heating means in a manner to heat
said object according to said preset heating sequence, and
wherein that said display means displays said selected heating
-- 6
sequence.
The present invention is explained hereafter reEerring to
the attached drawings.
FIGURE 1 shows a perspective view of an embodiment of a
heating apparatus in accordance with the present invention,
wherein the numeral 1 designates an enclosure case, 2 designates
a door which shuts an opening of a heating chamber, and 3
designates a front panel illustrated in FIGURE 2 in more detail.
As shown in FIGURE 2, the front panel 3 has a connecting
socket 4, which connects a microphone 5 through a cable 6 and a
connector 7 as shown in FIGURE 1 for applying a voice command to
a voice recognition part, another microphone ~ built in the
enclosure case 1 for applying voice command to the voice
recognition part, a switch 9 for changing whether the voice
recognition part operates or not, and a display which may
comprise fluorescent indication tubes 10 of four figures which
can indicate numerals and some letters of alphabet. On the front
panel 3, there are push buttons of a manual input part, namely,
time setting keys 11, 12, 13 and 14 which set heating period to
be indicated by figures of the fluorescent indication tubes 10, a
switch 15 which selects below mentioned heating sequence, a
switch 16 which selects strength of the output power, a stop
key 17 which stops heating or makes a selected heating sequence
clear, and a start key 18 which starts the action of heating.
Furthermore, there are indication lamps 19, 20 and 21, and a
buzzer 22 on the front panel 3. The indication lamp 19 indicates
an inquiry to user as to whether the heating apparatus should
start to heat or not, the indication lamp 20 indicates that the
æ
apparatus is prepared to receive a voice command, and the
indication lamp 21 indicates that the received voice command has
been recognized. The buzzer 22 indicates the recognition of the
voice commands, the termination of heating etc.
FIGURE 3 shows a block diagram of the preferred embodiment
in accordance with the present invention. Voice commands of
users are applied to a voice recognition part 23. The voice
recognition part 23 stores finite recognizable standard
instructions in a below-mentioned manner and compares the voice
command with the stored standard instructions in a
below~mentioned manner, The applied voice command is recognized
by the voice recognition part 23 and one of a plurality of
recognition codes as shown in FIGURE 4 is fed to a control
part 24~ For example, in case a voice command "AUTO" is applied,
the voice recognition part 23 generates a recognition code "5"
and send it to the control part 24. FIGURE 4 shows a list of an
example of standard instructions for controllin~ the heating
apparatus in command voice, whose words are used in every day.
The standard instructions shown in FIGURE 4 are only one example
of predetermined codes listr and the words to be pre-registered
as standard instructions are not limited to these words. The
recognition code "5", namely the instruction "AUTO", means an
automatic heating operation which automatically controls heatin~
of a heating object and stop.s after heating ~or a predetermined
time by inputting a name of cooking or material such as "BEEF" as
described lower than the recognition code "5" in FIGURE 4. Such
automatic heating is embodied by the control part 24 and an
object condition detecting part 26. The object condition
æ
detecting part 26 detects a heating condition o a heating
object 32 by measuring a temperature of the heating object 32
using a detecting device inserted into the heating object 32 or
by simpl~ measuring a temperature of a heating chamber 29. The
heating condition can be detected by using humidity change of the
heating chamber 29 where the heating object 32 generates moisture
as described in FIGURE 5. The control part 24 preliminarily
stores a plurality of heating sequences with regard to the kind
of cooking or materials so as to carry out automatic heating
operation without setting heating time. With this structure,
various kinds of heating operations can be automated using only a
few words for recognition.
~fter one heating sequence is selected from the plurality of
heating sequences available, the selection being made by a voice
command, the selected heating sequence is indicated by display
part 25. Then the control part 24 controls heater members ~7
such as a magnetron, a fan etc. in a manner to execute the
selected heating sequence when a voice co~nand for starting
heating is given to the apparatus.
FIGURE 5(a) shows one example of the heating apparatus of
the present invention using a humidity sensor disposed at a part
of the heating chamber 29 wherein the heating object 32 is
disposed as the object condition detecting part 26. A
magnetron 30 generates microwave energy and radiates it into the
heating chamber 29 through an opening 31 of a waveguide. Wind
generated by the fan 33 flows by the magnetron 30 to cool it down
and is conducted into the heating chamber 29 as shown by
arrows 34 and 35 in FiGURE 5(a). As the heating object 32 is
heated, moisture contained in the heating object 3Z evaporates,
and is exhausted from the eating chamber 29 to an e~haust
guide 38 as shown by arrows 36 and 37. A humidity sensor 39 is
disposed in the exhaust guide 38, to detect the humidity of the
exhausted air. FIGURE 5(b) shows a humidity change with respect
to the heating time t.
In FIGURE 5(b), at the time t = to, the heating of the
heating object 32 starts. At the initial stage of the heating,
the humidity slightly decreases by the rise of the temperature,
as a result of evaporation of water in the heating object 32. By
defining that a time length Tl is from the time to f a start of
heating till the time tl when the humidity increase ~H exceeds a
predetermined value, then a period T2 from the time tl to the
time t2 of the end of heating can be determined as a function of
Tl, for example an equation T2 = K X Tl (K: const.). And by
preliminarily preparing various values of K corresponding to
kinds of cooking or materials are preliminarily set the heating
apparatus can automatically cook various kinds of heating
object 32. By selecting the values K, the user can safely cook
by a simple selection of cooking kind, without necessity of
setting time period of heating for each heating object.
-- 10 --
The prlnciple of voice recognition is made such
that the voice command is analyzed to a time sequential pattern
. data and compared with a preliminarily stored pattern analyzed
data of the standard instructions, and then a search ls made
to find a standard instruction whose analyzed data is substan-
tially identical to that of the voice command.
The circuit structure of an example of the apparatus
in accordance with the present invention is elucidated herein-
after referring to the drawings of FIGURES 6, 7, 8, 9, lO(a),
lO(b), lO(c), ll and 12.
In FIGURE 6, the microphone 5 or 8 receives the user's
voiee eommand and converts the voice command to a voice electric
signal, which is amplified by an amplifier 41 with an automatic
gain control eircuit 42. The voice electric signal is then led
to a filter bank 43 comprising a plurality of band-pass filters
44 and low-pass filters 45. FIGURE 7 shows an example of an
actual cireuit strueture of such filter bank 43, which comprises
multiple feed-baek type band-pass filters Fl, F2, ...., Fn and
multiple feed-back type low-pass filters Ll, L2, ...., Ln. The
band-pass filters Fl to Fn have frequency characteristics shown
in FIGURE 8, wherein a frequency range of lO0 Hz to lO KHz is
covered by ten band-pass filters Fl to Flo, wherein the center
frequencies fj and the band width B; ~; = l, 2, ...., lO) are
designed as shown in FIGURE 8.
The low-pass filters 45 have the cut-off frequencies as
shown in FIGURE 9. In the example, the low-pass filters 45 are
12
of multiple feed-back type having the cut-off frequencies of
50 Hz. s~ using such Eilter bank 43, the command voice Vin is
analyzed into data in ten frequency bands. FIGURE 10(a) shows
the voice waveform Vin and FIGURE 10(b) shows waveform of the
output signal VBpF of a band-pass filter. As shown in FIGURE
10(b), the waveform of the signal VBpF contains pitch of the
voice, and therefore, the signal VBpF is passed through the
low-pass filter to remove the pitch and obtain a filter bank
output VF of smoothed envelope waveform as shown by FIGURE 10(c).
The larger the number of the filters, the better the analysis
of the voice pattern can be made. However, the use of too many
filters makes the cost and bulk of the apParatus too large,
and therefore, a reasonable number for a home use utensil should
be selected in considering a suitable recognition ability and
speed of controlling part from both aspec~s o~ software and
hardware. For the case wherein a below-mentioned 8-bit micro-
processor is used for its control part, 10 filters each for
the band-pass filters and low-pass filters are empirically found
suitable or effective. The output signal of the filter bank 43
is then led into the analog multiplexer 46, and the outputs oE
the low-pass filters Ll, L2, L3, ...., Llo are in turn sent to
the multiplexer 46 and the output of the multiplexer 46 is
subject to samplïng by an A/D converter 49. The analog multi-
plexer 46 is, as shown in FIGURE 11, comprises ten analog switch
47, which are consists of, for example, three C-MOS devices of
MC14016B (a four circuits analog switch) produced by Motorola Inc.
13
30~
Channel switching is operated by channel selection signal sent
from the CPU ln the control part. A decoder 48 decodes the
4-bits binary type channel selection signal into 10-bits signal
to be given to the multiplexer 46. The decoder 48 is structured
by using a BCD to Decimal Decoder of MC14028B produced by
Motorola Inc. For example, when a "0001" signal is input, the
decoder 48 outputs channel 1. Accordingly, the signal VF2 is
sent to the output terminal of the analog multiplexer 46. By
switching the channel selection signal in the similar manner,
outputs of ten filters of the filter bank 43 are issued in turn
at the output terminal of the multiplexer 46.
Then, the output signals o the filter bank 43 are
sent to the A/D converter 49 and converted into 8-bits digital
signals. The A/D converter 49 is consists of, for example, a
monolithic A/D converter M~i 5357 of NS Inc. By adjusting the
load resistors ~Ll and RL2, the analog input signal is adjusted
to be within +5 V. The input terminal SC of the A/D converter
49 receives a start conversion signal, by which output signal of
the analog multiplexer 46 is sampled with a period of between 1
and 10 m sec. With such period, enough pattern characteristic
recognition can be made when the voice waveform is handled as
envelope signals. The output terminal EOC outputs an end-of-
conversion signal, and the output terminal OE outputs an output-
enable signal having effective timing of the 8-bits digital out-
put signal. The CPU 50 in turn samples the filter bank outputs
by mPans of the SC signal, sweepingly outputting the channel
14 3~ 3 0 ~ ~
selection signal, and converts into 8-bits digital data, and
the abovementioned processing is made by using the OE signal as
monitor.
FIGURE 12 shows a block diagram of one example of such
CPU system 50, constituted by using an 8-bits microprocessor,
Intel 8080. The voice data (8-bits digital signal) is written
into an input pattern memory 52 through the bi-directional data
bus 51 (shown in FIGURE 6). That is, the 8-bits voice data
issued from the A/D converter 49 is sent to the bi~directional
lo data bus 51 in a data reading mode under the control of
the multiplexer 53. The voice data is once written into the
input pattern memory 52 by a control signal from the CPU 50. By
means of such process, the voice data in the input memory 52 are
analyzed in every frequency band, and then is sampled by the
A/D converter 49.
Then by detecting of the end of the voice input signal,
the CPU 50 counts the time length T (FIGURE 10~c)) of this voice
input pattern, and normalizes this time length by utilizing known
dynamic program~ing (DP), in which DP process, the input voice
pattern is compared to the reference pattern registered i.n the
reference pattexn memory 54, and partial expansion or partial
compression is carried out until the voice input pattern most close-
ly coincides with the reference pattern, so that a reference pattern
with highest affinity with the input pattern is selected.
For more information on the DP t~nique applied for the voice reo~g-
nition, reference is made to, for example ~E~ Transactions on Acoustics, Speech,
and Signal processing, Vol. ASSP-26, No.l, pp. 43-49, February 1978, and Vol.
ASSP-27, No. 6, pp. 588-595, December 1980.
Læ
By means of the abovementioned recognition process,
the voice input signal is decided as being coincided with the selec-
ted reference pattern, and therefore, a specified output signal is
provided to a multiplexer 55 for controlling output means. Thereby,
as shown in FIGU~ 13, a heating starting signal ON, an indica-
tion data for the fluorescent indication tube, the aforementioned
channel selection signal or sampling signal SC are issued with
the same predetermined timings that decides timings of an output
port decoder 56.
~ FIGURE 13 is a block diagram o~ an output control circuit. The
output port decoder 56 causes the output signal from the bi-
directional data bus 51 through a multiplexer 55 to be selected
to be given to the channel selection signal, the fluorescent
indication tubes 10, o~ the heater members 27, respectively.
The heating starting signal O~ is generated as a pulse,
but is smoothed by a capacitor 57, and then turns a transistor
58 on and energizes a relay 59. sy the energization of the
relay 59, the contact 59a of the relay 59 closes and electric
energy is fed to the magnetron 30. Upon a termination of the
heating time or by manual pushing of the stop key 17, the
signal ON changes to "L" level, and the contact 59a of the relay
59 opens and stops feeding the electric energy to the magnetron
30. The fluorescent indication tube 10 is dynamic-driven by
the signals DiC4 to DiGo. The signals CH3 to CHo are channel
selecting signals and control the decoder 48 as mentioned above.
The signal SC is a sampling pulse of the ~/D converter 49.
The structure of the memory is e.Yplained below referring to a
emory area map of FICURE 14. A program memory 60 in FICURE 12
16
stores control program and data for the CPU 50 in allotted
addresses of HEX(hexadecimal)"0000" to HEX"E~". Necessary memory devices æe
actually provided within the address. A read and write memory
such as a core memory or an IC memory is used for the mem~ry 6~. In case a~
(read only memory) is used for control program per se and a ~-1(randam access
memory) for data, the memory system becomes compact and cheap.As shown in
FIGURE 14, addresses of HEX"~i~00" to HEX"~ "are allotted for the
input pattern memory 52 and the reference pattern memory 54.
The input pattern memory 52 can be embodied by using a read
lo and write memory, a R~, while the reference pattern memory 54
can be embodied by use of a R~ in case voice command data of one
or several limited users are preliminarily stored in-the ~ 54
in order to easily obtain recognition of the user's voice with
the stored reference pattern. However, in order to recognize a
voice command of an unlimited user, a standard reference voice
pattern has to be stored in the reference pattern memory 54
consisting of a ROM.
By the abovementioned structure and process, the voice
command "AUTO" is recognized. The recognition code is predeter-
mined corresponding to the voice command as shown in FIGURE 4.
In this case, since the voice command is "AUTO", the recognition
circuit 63 generates the recognition code "5" after the recog-
nition operation and sends the code to the control part 24. The
recognition circuit 63 sends a READY signal which indicates
a ready state for sound receiving is accomplished, and a REJECT
signal which indicates a failure of the recognition.
~3~
In FIGURE 6, the control part 24 and the recognition
circuit 63 are structured by one CPU. However, the recognition
circuit 63 and the control part 24 can be structured by two
CPUs.
In the meantime, the control circuit 24 receives the
recognition code "5" indicating -the voice command "A~TO", and
accordingly the display part 25 indicates the result of the
recognition. The indication is performed, for example, by a
short beep of the buzzer 22 and a lighting of the indication
lamp 21. And in order to indicate the voice command "AUTO", the
letter "A" is lit at the second position of the fluorescent
indication tube 10 as shown in FIGURE 2. Furthermore, the
indication lamp 20 is lit so as to indicate that now an input of
a cooking name (for example the voice command "BEEF" etc.) can
be received and is required.
The input using the voice commands is convenient for
users since a manual operation is unnecessary. On the contrary,
users may be apprehensive as to whether the heating apparatus recog-
nizes the voice commands correctly or not. Therefore, in the pre~ent
~o invention, the abovementioned simple display means indicate the
recognition result to the users.
Yurthermore, it will be difficult to distinguish the
voice command of the user from an ambient noise, and mal-operation
may occur by other people's unconscious pronunciation against the
will of the user. Therefore, in order to improve such disadvan-
tages, the heating apparatus of the present invention are structured
18
in a manner to ignore the instructions unless two or more words
are not applied in the predetermined order. Namely, the micro-
processor of the control part 24 is programmed such that a voice
command to follow the word "AUTO" must be a cooking name. For
example, the voice command must be "AUTO" followed by "BEEF" or
"AUTO" followed by "BACON".
In this example, after the recognition of the voice
command "AUTO", a voice command of cooking name must be instructed.
Even if a voice command "START" is recognized, such voice command
lo is ignored since it is not within the sequence of the program.
Besides, unless an appropriate voice command of cooking name is
applied in a predetermined period after the voice command "AUT0",
the recognized voice comm~nd "AUT0" is automatically cancelled
in order to avoid mal operation based on noise etc.
It rarely occurs that two or more erroneous commands
are recognized successivelv by noise, accordingly mal-ope.ration
of the heating apparatus can be avo~ded. Furthermore, since the
control part 24 and the recognition circuit 63 are structured
by one CPU as the abovementioned embodiment after the recognition
of the voîce command "AUT0", the apparatus can be structured in
a manner to receive only a voice command of cooking name or
"RESET". Therefore, the recognition circuit 63 do without
comparing the applied voice command with voice commands except
these allowable voice commands, and recognition speed can be
improved.
Returning to the abovementioned arguments, a voice
1~3
command "POTATOES " iS provided to the heating apparatus
following to the voice command "AUT0", the control part 24
` controls the display part 25 so as to light on the indication
lamps 20 and 21 (these indica-tion lamps turn off when the second
voice command is applied) and to indicate user the completion of
recognition. At that time r the voice commands are regarded
as being correct, and therefore the program is set such that a heating
sequence corresponding to this cooking is selected from the
preliminary stored heating sequences and is preset to the memory
60. In order to indicate the selected heating sequence, a number
"9", which corresponds to the heating sequence of potato as
shown in FIGURE 4, is lit at the third posltion o~ the fluorescent
indication tube lO as shown in FUGURE 2.
sy the a~ovementioned operation, the preparation of
heating is accomplished. Then~ the user says "START" to the
microphone 5 or 8, the voice command is received by the voice
command input means 61, and the voice pattern is analyzed by the
pattern analyzer 62 and stored in the input pattern memory 52.
And the voice command is finally converted to the recognition
code "l" in the recognition circuit 63. The recognition code
"l" is applied to the control part 24 and causing a starting of
a preparation for feeding electric power to the magnetron 30.
At that time, the indication lamp 21 is lit for indicating the
recognition of the voice command "START". And simultaneously
the indication lamp l9 of "START?" is lit for asking the user
whether the heating operation should be actually started or not.
630~
If the voice command "YES" is not fed to the heating apparatus
in a predetermined time, the recoynized voice command "START"
per se is reset. The heating operation does not start until
the voice command "YES" is recognized and the recognition code
is fed to the control part 24. Namely an ON signal is applied to
the transistor 58 as shown in FIGURE 13, thereby the magnetron
30 starts heating. In case the user wishes to stop the heating
operation, sheinstructs "STOP" to the heating apparatus with the
voice command, so that ON signal is changed to "OFF" and stops
heating by deenergizing the relay 59.
The heating apparatus of the present invention can be
structured in a manner that manual input from the manual input
part 28 can be received by the apparatu~ even when the apparatus
is in the voice recognition mode. At that time, it may possible
. to modify a part of a heating sequence, or to select a user's
original heating sequence preliminary stored in a ~ by a voice
command after the voice command of "AUTO".
