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BACKGROUND OF THE INVENTION
The present invention generally relates to rotary recording medium
reproducing apparatuses, and more particularly to a reproducing apparatus
which is designed to satisfactorily reproduce recorded signals from a
single continuous spiral track on the same side of a rotary recording
medium, at the same rotational speed with respect to digital recorded
tracks and analog recorded tracks which constitute the spiral track and
coexist on the same side of the rotary recording medium, where the digital
recorded tracks are recorded with digitally modulated information signals
and the analog recorded tracks are recorded with analog modulated
information signals.
There is a known type of a rotary recording medium (hereinafter simply
referred to as a disc) which is recorded with analog information signals
such as a composite video signal and audio signals. In such a disc, the
analog information signals are subjected to a frequency modulation, for
example, and are recorded on a spiral track or concentric tracks on the
disc as variations in geometrical configuration, for example. This disc is
often referred to as a video disc because the recorded information mainly
includes the composite video signal. The composite video signal or the
like is recorded on the tracks on the video disc in the form of modulated
signals which are obtained by modulating a carrier by the analog
information signals. An address signal which is used for random access and
the like, is recorded within a predetermined duration within a vertical
blanking period of the composite video signal, for example. The address
signal itself is an encoded digital signal, however, the main information
recorded on the video disc is the analog modulated composite video signal
or the like. Hence, in the present specification, tracks such as the
recorded tracks of this video disc, will be referred to as "analog
recorded tracks" for convenience' sake.
On the other hand, there is another type of a disc which is recorded with
digital signals. In such a disc, audio signals or audio and video signals
are subjected to a digital modulation, and are time-sequentially
multiplexed and recorded on concentric tracks or a spiral track on the
disc as variations in geometrical configuration, for example. This disc is
often referred to as a digital audio disc because the recorded information
mainly includes the audio signals, and the video signal mainly relates to
a still picture and is simply recorded as a supplementary information to
help the listener with his imagination. The audio signals or the audio and
video signals are recorded on the tracks on the digital audio disc after
being converted into the form of digital signals which are obtained by
subjecting the audio signals or the audio and video signals to a digital
modulation and then subjecting the digital modulated signals to a
frequency modulation or the like. In the present specification, tracks
such as the recorded tracks of this digital audio disc, will be referred
to as "digital recorded tracks" for convenience' sake.
In an electrostatic capacitance type video disc proposed in a U.S. Pat. No.
4,331,976, the recorded signals are reproduced from the video disc by
detecting the variations in the electrostatic capacitance which is formed
between the video disc and an electrode of a reproducing stylus. Reference
signals for tracking control, are recorded on both sides of the
information signal recorded track (analog recorded track) According to
this video disc, the need for a stylus guide groove was eliminated by use
of the reference signals, is known. In this known video disc, a tracking
control was carried out with respect to the reproducing stylus so that the
reproducing stylus accurately scans over the information recorded track
during the reproduction mode, by comparing the levels of the reference
signals which are reproduced from the video disc.
On the other hand, an electrostatic capacitance type digital audio disc is
also known. The electrostatic capacitance type digital audio disc has no
stylus guide groove and is recorded with reference signals for tracking
control on both sides of the information signal recorded track (digital
recorded track), similarly as in the case of the electrostatic capacitance
type video disc. During the reproducing mode, this electrostatic
capacitance type digital audio disc is rotated at a predetermined
rotational speed which is the same as the rotational speed of the
electrostatic capacitance type video disc. The frequencies of the
reference signals and the method of reproducing the reference signals, are
the same between the electrostatic capacitance type digital audio disc and
the electrostatic capacitance type video disc. Further, in both the
electrostatic capacitance type digital audio disc and the electrostatic
capacitance type video disc, the recorded signals are reproduced from the
disc by detecting the variations in the electrostatic capacitance between
the disc and the electrode of the reproducing stylus. For these reasons,
even when the digital audio disc is played on a video disc reproducing
apparatus which is designed to play the video disc, the tracking control
is carried out with respect to the reproducing stylus similarly as in the
case where the video disc is played, and the recorded signals can be
picked up and reproduced from the digital audio disc by the reproducing
stylus. The signals which are reproduced from the digital audio disc, are
demodulated into original audio signals or the like in an adapter which is
coupled to the video disc reproducing apparatus.
Accordingly, the previously proposed electrostatic capacitance type video
disc and the electrostatic capacitance type digital audio disc can be
played on the same electrostatic capacitance type video disc reproducing
apparatus. In other words, the above video disc and the digital audio disc
can be played compatibly on the same video disc reproducing apparatus.
However, the digital audio disc and the video disc were mutually
independent discs, and the compatibility did not exist in the true sense
of the word. On the other hand, the digital audio disc is recorded with
digital signals. Thus, compared to the video disc, the audio signals are
reproduced from the digital audio disc with a wide dynamic range and with
an extremely high fidelity, due to the characteristics of the digital
signal transmission. Moreover, the still picture which is reproduced from
the digital audio disc is extremely sharp, and there is of course an
advantage in that the audio signals are reproduced from the digital audio
disc with an extremely high fidelity together with the still picture. On
the other hand, the still picture is reproduced from the video disc by
repeatedly reproducing the same track on the video disc. Generally, the
audio signals are muted during the still picture reproduction, and it is
impossible to simultaneously reproduce the audio signals and the video
signal from the video disc. However, due to the analog signal transmission
in the video disc, it is possible to transmit the information signals in
real time with a frequency band in the range of several MHz according to
the video disc. Thus, compared to the digital audio disc in which the
information signals are transmitted with a frequency band in the range of
several tens of kHz in order to improve the transmitting accuracy, the
video disc is advantageous in that it is possible to simultaneously
reproduce a moving picture and the audio signals. Accordingly, in order to
ensure optimum reproduction of the recorded signals, it is desirable to
select and reproduce one of the digital signals and the analog signals
depending on the information contents.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a
novel and useful disc reproducing apparatus in which the problems
described heretofore have been eliminated.
Another and more specific object of the present invention is to provide a
disc reproducing apparatus which is designed to satisfactorily reproduce
pre-recorded signals from a single continuous spiral track on the same
side of a disc, at the same rotational speed with respect to digital
recorded tracks and analog recorded tracks which constitute the spiral
track and coexist on the same side of the disc, where the digital recorded
tracks are recorded with digitally modulated information signals which
have been subjected to a further modulation and the analog recorded tracks
are recorded with analog modulated information signals including a
composite video signal. The disc reproducing apparatus according to the
present invention comprises a first reproducing circuit for reproducing a
composite video signal from the signal which is reproduced from the analog
recorded tracks, a second reproducing circuit for demodulating and
reproducing the signal which is reproduced from the digital recorded
tracks into the original information signal, and a circuit for supplying a
master clock signal to the second reproducing circuit.
According to the apparatus of the present invention, the recorded tracks
can be reproduced satisfactorily regardless of whether the recorded tracks
are the digital recorded tracks or the analog recorded tracks, and a
perfect compatible reproduction can be achieved. Especially from the
analog recorded tracks, it is possible to reproduce a video information
related to a moving picture together with an audio information. Further,
from the digital recorded tracks, it is possible to reproduce a video
information related to a still picture which is extremely sharp compared
to the still picture information reproduced from the conventional video
disc, together with an audio information. In addition, from the digital
recorded tracks, it is possible to reproduce an audio information with a
wide dynamic range and with an extremely high fidelity compared to the
audio information reproduced from the conventional video disc. In other
words, it is possible to reproduce audio and video information from the
disc with an improved artistic touch, compared to the conventional video
disc and the conventional digital audio disc.
Still another object of the present invention is to provide a disc
reproducing apparatus comprising first and second switching circuit means.
The first switching circuit means selectively produces an output signal of
a first oscillator circuit as an external synchronizing signal for a disc
rotating motor when reproducing pre-recorded signals from a first disc on
which the analog recorded tracks and the digital recorded tracks coexist
or the conventional video disc (second disc), and selectively produces a
signal which is obtained by frequency-dividing an output signal of a
second oscillator circuit as the external synchronizing signal when
reproducing pre-recorded signals from the conventional digital audio disc
(third disc). The second switching circuit means selectively produces a
signal which is obtained by frequency-multiplying the output signal of the
first oscillator circuit as a master clock signal for the second
reproducing circuit which demodulates and reproduces the original
information signal from the signal which is reproduced from the digital
recorded tracks, when reproducing the pre-recorded signals from the first
disc. The second switching circuit means selectively produces the output
signal of the second oscillator means as the master clock signal when
reproducing the pre-recorded signals from the third disc. According to the
apparatus of the present invention, it is possible to compatibly reproduce
the pre-recorded signals from the first, second, and third discs.
A further object of the present invention is to provide a disc reproducing
apparatus in which the rotational speed of the disc is controlled
according to the number of scanning lines employed in the composite video
signal which is pre-recorded on the analog recorded tracks, so that the
frequency of the reproduced horizontal synchronizing signal becomes a
constant frequency. According to the apparatus of the present invention,
it is possible to reproduce and display the composite video signal
regardless of the number of scanning lines employed in the composite video
signal which is pre-recorded on the analog recorded tracks. In addition,
it is possible to reproduce audio signals from the digital recorded tracks
with a high quality and a high fidelity, and also satisfactorily reproduce
a video signal (especially related to a still picture) from the digital
recorded tracks.
Other objects and further features of the present invention will be
apparent from the following detailed description when read in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a systematic block diagram showing an example of a recording
system of a disc which is to be played;
FIG. 2 shows an example of a signal format of one block of digital signal
which is recorded on digital recorded tracks on the disc which is to be
played;
FIG. 3 shows an example of a signal format of each of address codes which
are recorded on the digital recorded tracks on the disc which is to be
played;
FIG. 4 shows an example of a signal format of a digital video signal which
is recorded on the digital recorded tracks on the disc which is to be
played;
FIG. 5 shows a part of the signal format shown in FIG. 4 in more detail;
FIG. 6 shows an example of frequency spectrums of frequency modulated
signals and reference signals which are recorded on the digital recorded
tracks on the disc which is to be played;
FIG. 7 shows an example of frequency spectrums of frequency modulated
signals and reference signals which are recorded on analog recorded tracks
on the disc which is to be played;
FIG. 8 shows an example of a track pattern on the disc which is to be
played;
FIG. 9 is a systematic block diagram showing another example of a recording
system for recording the disc which is to be played;
FIG. 10 is a systematic block diagram showing an embodiment of a disc
reproducing apparatus according to the present invention;
FIG. 11 shows an example of an 8-pin connector used in the reproducing
apparatus;
FIG. 12 shows an example of a format of an essential part of a status
signal which is serially produced from a microprocessor within the block
system shown in FIG. 10; and
FIG. 13 is a circuit diagram showing an embodiment of a switching circuit
within the block system shown in FIG. 10.
DETAILED DESCRIPTION
In FIG. 1, 2-channel video tape recorders (VTRs) 11 and 12 are each
supplied with a synchronizing signal from respective PCM recording and
reproducing apparatuses 13 and 14. On the other hand, the VTRs 11 and 12
each reproduce a 2-channel information signal which has been pre-recorded
on a magnetic tape, and the reproduced information signals from the VTRs
11 and 12 are supplied to the respective PCM recording and reproducing
apparatuses 13 and 14 to be recorded. The reproduced information signals
from the VTRs 11 and 12, may be 2-channel audio signals, one channel of a
monaural audio signal and another channel of a monaural audio signal or a
still picture signal, or two channels of still picture signals. For
example, the still picture signals have a signal format in which component
coded data obtained by subjecting signals related to still pictures which
are only in video durations of a composite color video signal employing
625 scanning lines to a digital modulation, are successively inserted into
video durations of a composite synchronizing signal which is in
conformance with the NTSC system.
The PCM recording and reproducing apparatuses 13 and 14 each subject an
input signal to a pulse code modulation (PCM), and generate an error
detecting code and error correcting codes so as to form a PCM signal
including the pulse code modulated signal and these codes. The PCM
recording and reproducing apparatuses 13 and 14 each add to this PCM
signal horizontal and vertical synchronizing signals which are in
conformance with the NTSC system, and record the signal which is obtained
to a magnetic tape and reproduce the signal from the magnetic tape. For
example, the PCM recording and reproducing apparatuses 13 and 14 each
record 6 information words (3 words in each of the right and left
channels) in one horizontal scanning period (1H). Since the data is not
transmitted in a duration of 35H in one frame, a sampling frequency
f.sub.s can be described by an equation f.sub.s =3.times.f.sub.H
.times.(525-35)/525, where f.sub.H is a horizontal scanning frequency. The
PCM recording and reproducing apparatuses are operated in synchronism with
a signal from an oscillator 15 having a frequency of 15.734 kHz which is
equal to the horizontal scanning frequency of the NTSC system. Thus, when
the frequency of 15.734 kHz is substituted into the above equation, the
sampling frequency f.sub.s becomes equal to 44.056 kHz.
A total of four channels of digital signals having the sampling frequency
of 44.056 kHz and a quantization number of 16 bits, are respectively
supplied to a digital signal processing circuit 16 from the PCM recording
and reproducing apparatuses 13 and 14. The digital signal processing
circuit 16 generates a signal of one block (frame) having a signal format
shown in FIG. 2, under control of an output signal of a controller 17. The
digital signal processing circuit 16 time-sequentially multiplexes the
generated signal in terms of blocks, at a transmission frequency of 44.056
kHz. Further, the digital signal processing circuit 16 obtains a frequency
modulated signal by frequency-modulating a carrier having a frequency in
the range of 7 MHz, for example, by the time-sequentially multiplexed
signal, and applies this frequency modulated signal to a terminal 18a of a
switching circuit 18.
In the signal of one block shown in FIG. 2, S indicates the position of a
synchronizing signal which has an 8-bit fixed pattern and identifies the
beginning of a block. Ch-1, Ch-2, Ch-3, and Ch-4 respectively indicate the
position of one word of a digital signal having 16 bits. This digital
signal may be a digital audio signal which is obtained by subjecting an
audio signal to a pulse code modulation, or a digital video signal which
is obtained by subjecting a video signal to a pulse code modulation. For
example, the signals described under one of the following cases (a)
through (d) may be arranged in the positions Ch-1 through Ch-4.
(a) A case where one word of each of four channels of digital audio
signals, is arranged in the positions Ch-1 through Ch-4.
(b) A case where one word of each of three channels of digital audio
signals is arranged in the positions Ch-1 through Ch-3, and two picture
element data of a digital video signal having a quantization number of 8
bits, for example, are arranged in the position Ch-4.
(c) A case where data of each of the channels in a first 2-channel stereo
digital audio signal are arranged in the positions Ch-1 and Ch-2, and data
of each of the channels in a second 2-channel stereo digital audio signal
are arranged in the positions Ch-3 and Ch-4.
(d) A case where data of each of the channels in a 2-channel digital audio
signal are arranged in the positions Ch-1 and Ch-2, and picture element
data of the same kind or different kinds of digital video signal having a
quantization number of 8 bits are arranged in the positions Ch-3 and Ch-4.
In addition, P and Q in FIG. 2 indicate positions of 16-bit error
correcting codes. Further, CRC indicates a position of a 23-bit error
detecting code. The error detecting code is a 23-bit remainder which is
obtained when each of the words arranged in the positions Ch-1 through
Ch-4, P, and Q of the same block are divided by a generating polynomial of
X.sup.23 +X.sup.5 +X.sup.4 +X+1, for example. When the signals in the 9-th
through 127-th bits of the same block are divided by the above generating
polynomial during the reproduction and the remainder is zero, it is
detected that there is no error in that block. Moreover, in FIG. 2, Adr
indicates a multiplexing position of 1 bit of one of various kinds of
address signals which are used during a random access and the like. The
bits of the address signal are distributed, and 1 bit of the address
signal is transmitted in one block. For example, all of the bits of the
address signal are transmitted in 196 blocks (in this case, the address
signal has 196 bits).
In FIG. 2, U indicates a position of a 2-bit signal which is often called
user's bits. One block of the digital signal is therefore made up of 130
bits from the position S to the position U. The digital signal is
time-sequentially multiplexed and transmitted in terms of blocks, at a
frequency of 44.056 kHz which is equal to the sampling frequency of the
digital audio signal.
For example, the 196-bit address signal is time-sequentially made up from
four kinds of address codes each having 49 bits. The four kinds of address
codes comprise a time address code and first through third chapter address
codes, for example, and the constitution of each address code is the same.
The address codes each have a signal format shown in FIG. 3. In FIG. 3, a
24-bit synchronizing signal is arranged in the first 24 bits of the
address code as indicated by SYNC. The value of the 24-bit synchronizing
signal differs depending on the four kinds of address codes. 4 bits which
are subsequent to the 24-bit synchronizing signal, includes a source mode
signal, a normal/stop mode discriminating signal, and the like. The source
mode signal indicates the source mode, that is, the combination of the
recorded signals from among the cases (a) through (d) described before.
The normal/stop mode discriminating signal indicates whether the video
disc player should assume a stop reproduction mode in which the same track
turn is repeatedly reproduced. The address data is located in the 20 bits
which are subsequent to these 4 bits, and the last 1 bit of the address
code is a parity bit.
In the case of the time address code, the address data is a time data which
indicates the reproducing time which would take in the normal reproduction
mode to reach the track position where that time address code is recorded,
from the starting position where the recording of the programs was started
at the time of the recording. On the other hand, in the case of the
chapter address code, the address data indicates the location of the music
program which is recorded at the position where that chapter address code
is recorded, with respect to the starting position where the recording of
the programs was started at the time of the recording. Thus, the chapter
address code indicates that the music program is the third program from
the starting position on a disc, for example.
As will be described later on in the specification, an NTSC system color
video signal is recorded on a disc 22 at a rate of four fields in one
revolution of the disc 22. This means that the recorded signals are
reproduced in a state where the disc 22 is rotated at a rotational speed
of 889.1 (=(59.94/4).times.60) revolutions per minute. Hence, 2940
(.apprxeq.44.056.times.10.sup.3 .times.(4/59.94)) blocks (frames) are
recorded on and reproduced from the disc 22 in one revolution of the disc
22. Accordingly, the 196-bit address signal is recorded on and reproduced
from the disc 22, 15 times in one revolution of the disc 22.
When transmitting the digital video signal related to the still picture by
arranging the digital video signal in the position Ch-3 and/or the
position Ch-4 shown in FIG. 2, the picture element data of the luminance
signal, having a sampling frequency of 9 MHz and a quantization number of
8 bits, are converted into luminance picture element data having a
sampling frequency of 88.112 kHz. Moreover, the picture element data of
the two kinds of color difference signals (R-Y) and (B-Y), having a
sampling frequency of 2.25 MHz and a quantization number of 8 bits, are
converted into color difference picture element data having a sampling
frequency of 88.112 kHz. These luminance picture element data and color
difference picture element data corresponding to one frame, are
transmitted with a signal format shown in FIG. 4.
In FIG. 4, one word is made up of 16 bits, and each of the picture element
data having the quantization number of 8 bits are arranged in the upper 8
bits and the lower 8 bits of one word. Hence, two picture element data can
be transmitted in one word. The digital video signal corresponding to one
frame comprises a total of 199,728 words as shown in FIG. 4. Picture
element data groups Y.sub.V1 through YV.sub.456 of the digital luminance
signal each made up of 286 words, picture element data groups (R-Y).sub.V1
through (R-Y).sub.V114 and (B-Y).sub.V1 through (B-Y).sub.V114 of the
digital color difference signals each made up of 286 words, and a total of
684 header signals H.sub.V1 through H.sub.V684 each made up of 6 words and
multiplexed to the beginning of each of the picture element data groups,
are time-sequentially multiplexed in this digital video signal
corresponding to one frame.
A total of 572 luminance picture element data groups in the first vertical
column at the leftmost part of the screen are indicated by Y.sub.V1, and
each of the picture element data are arranged in sequence from the top of
the screen to the bottom of the screen. As shown in FIG. 5, a picture
element data Y.sub.0 at the uppermost part of the screen is arranged in
the upper 8 bits of the first word, and a picture element data Y.sub.456
at the second uppermost part of the screen is arranged in the lower 8 bits
of the first word. Similarly, a picture element data Y.sub.912 is arranged
in the upper 8 bits of the second word, a picture element data Y.sub.1368
is arranged in the lower 8 bits of the second word, a picture element data
Y.sub.1824 is arranged in the upper 8 bits of the third word, . . . , and
a picture element data Y.sub.260376 at the lowermost part of the screen is
arranged in the lower 8 bits of the 286-th word. A total of 572 luminance
picture element data groups in the second column from the left end of the
screen are indicated by Y.sub.V2 in FIG. 4, and a total of 572 luminance
picture element data groups in the third column from the left end of the
screen are indicated by Y.sub.V3. Similarly, a total of 572 luminance
picture element data groups in the i-th (i is an integer from 1 to 456)
column from the left end of the screen are indicated by Y.sub.Vi. Each of
the picture element data are arranged similarly as the above picture
element data group Y.sub.V1, and the picture element data corresponding to
one vertical column are transmitted by 286 words.
In addition, a total of 572 picture element data groups of the first
digital color difference signal arranged in the j-th (j is an integer from
1 to 114) column from the left end of the screen are indicated by
(R-Y).sub.Vj, and a total of 572 picture element data groups of the second
digital color difference signal arranged in the j-th column from the left
end of the screen are indicated by (B-Y).sub.Vj. Each of the 572 picture
element data groups corresponding to one column are arranged in a sequence
starting from the top to the bottom of the screen in the upper 8 bits of
the first word, lower 8 bits of the first word, upper 8 bits of the second
word, lower 8 bits of the second word, upper 8 bits of the third word, . .
. , and lower 8 bits of the 286-th word, and the picture element data
corresponding to one column are transmitted by 286 words. A header signal
having 6 bits, for example, is added to the beginning of each of the above
divided picture element data groups.
Further, as shown in FIG. 4, the above component coded signal has a signal
format in which the signal is time-sequentially transmitted in terms of
units, where one unit comprises a total of six picture element data
groups, that is, four picture element data groups Y.sub.V(4j-3),
Y.sub.V(4j-2), Y.sub.V(4j-1), and Y.sub.V(4j) and the two kinds of digital
color difference signals (R-Y).sub.Vj and (B-Y).sub.Vj.
As shown in FIG. 4, the header signals H.sub.1 through H.sub.684 are
respectively arranged at the beginnings fo each of the 684 picture element
data groups Y.sub.i, (R-Y).sub.j, and (B-Y).sub.j. The header signals are
transmitted as discriminating signals, so that the reproducing apparatus
can discriminate each of the various kinds of information contained in the
picture element data group which follows immediately after the header
signal. The header signals H.sub.1 through H.sub.684 each comprise 6 words
and have a common signal format.
Returning now to the description of FIG. 1, the digital signal processing
circuit 16 applies the frequency modulated signal (first FM signal) to the
terminal 18a of the switching circuit 18. A frequency spectrum of this
first FM signal is indicated by a solid line in FIG. 6. The carrier
frequency is equal to 7.6 MHz when the data is "1", and the carrier
frequency is equal to 5.8 MHz when the data is "0". In FIG. 6, frequency
spectrums represented by phantom lines fp1, fp2, and fp3, indicate the
frequency spectrums of reference signals fp1, fp2, and fp3 which are
recorded together with the first FM signal.
On the other hand, a VTR 19 plays a magnetic tape which has been
pre-recorded with an NTSC system color video signal related to a moving
picture and an audio signal, and supplies to an analog signal processing
circuit 20 the signals which are reproduced from the magnetic tape. The
analog signal processing circuit 20 generates a frequency modulated signal
having the same signal format as the frequency modulated signal which is
recorded on the video disc described before, and multiplexes each of the
various kinds of address signals within the vertical blanking period. The
concrete construction of the analog signal processing circuit 20 is
disclosed in the U.S. Pat. No. 4,208,671 in which the assignee is the same
as the assignee of the present application, for example, and is known.
Thus, detailed description will not be given with respect to the concrete
construction of the analog signal processing circuit 20.
The analog signal processing circuit 20 produces a band-share-multiplexed
signal in which a band limited luminance signal and a low-band-converted
carrier chrominance signal which has been frequency-converted into a low
frequency range are band-share-multiplexed. The analog signal processing
circuit 20 also independently produces a chapter address signal A.sub.C, a
time address signal A.sub.T, and a track number address signal A.sub.N.
These address signals are multiplexed into specific durations of 1H within
the vertical blanking period of the band-share-multiplexed signal, so as
to obtain a predetermined multiplexed signal. A predetermined carrier is
then frequency-modulated by a signal which is obtained by subjecting the
predetermined multiplexed signal to a frequency-division-multiplexing with
a frequency modulated audio signal. The address signal A.sub.C indicates
the recorded position on the disc in terms of the order of the recorded
programs, and the time address signal A.sub.T indicates the total
reproducing time. In addition, the track number address signal A.sub.N
indicates the number of tracks when it is assumed that one track is formed
from the recorded position of the reference signal fp3 as the disc
undergoes one revolution. The address signals A.sub.C, A.sub.T, and
A.sub.N each comprise 29 bits.
FIG. 7 shows a frequency spectrum of the output signal of the analog signal
processing circuit 20. In FIG. 7, I represents a carrier deviation band of
2.3 MHz of the frequency modulated luminance signal, f.sub.a represents a
frequency of 6.1 MHz corresponding to the tip end of the synchronizing
signal (sync tip), f.sub.b represents a frequency of 6.6 MHz corresponding
to the pedestal level, and f.sub.c represents a frequency of 7.9 MHz
corresponding to the white peak. Further, II.sub.U and II.sub.L
respectively represent upper and lower sidebands of the frequency
modulated luminance signal, and III.sub.U and III.sub.L respectively
represent upper and lower sidebands of the signal which is obtained by
further frequency-modulating frequency modulated audio signals f.sub.A1
and f.sub.A2. Moreover, IV represents carriers of 3.43 MHz and 3.73 MHz of
the 2-channel frequency modulated audio signals f.sub.A1 and f.sub.A2.
In addition, V represents a frequency band of the low-band-converted
carrier chrominance signal which is obtained by frequency-converting the
carrier chrominance signal within the reproduced signal from the VTR 19.
First sidebands which are obtained when the low-band-converted carrier
chrominance signal is frequency-modulated, are represented by VI.sub.U and
VI.sub.L, and second sidebands | | |
