JPH06121277A - Recording and reproducing system for video signal - Google Patents

Abstract

PURPOSE:To display relic lines when a KARAOKE (accompaniment to recorded music) video is played by superposedly displaying information such as a charac ter video image obtained based on a DC formed signal. CONSTITUTION:A timing generating circuit receiving a horizontal synchronizing signal from a horizontal synchronizing separator circuit 47 generates a timing signal based on the horizontal synchronizing signal and gives the signal to an identification signal extraction circuit. The identification signal extraction circuit extracts an identification included in a video output from a video demodulation system 16 synchronously with the timing signal to be supplied. Furthermore, a reproduction mode discrimination circuit discriminates the reproduction mode based on the identification signal extracted by the identification signal extraction circuit to control an audio output system to reproduce each information signal in the reproduction mode. Then a video image based on a CD format signal is superimposed on the video image based on a video format signal obtained from the demodulation signal and the superimposed signal is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing system for recording a plurality of information signals of different modulation systems on a recording medium and reproducing the information signals.

[0002]

2. Description of the Related Art As a recording medium, particularly a disc-shaped recording medium, a digital audio disc, which is a so-called compact disc (hereinafter abbreviated as CD), in which an audio signal is subjected to predetermined digital modulation processing and pulse trained, and recorded, and a video signal are recorded. A video disc (hereinafter abbreviated as LD) in which an audio signal and an audio signal are frequency-modulated and recorded is known, and more recently, an audio signal is converted into an FM modulation signal of the video signal and the audio signal by a predetermined digital modulation method. A system in which the digitized pulse train signal is superimposed and recorded (Japanese Patent Application No. 58-45).
Video disk (hereinafter LD)
(Abbreviated as D) has been developed.

In such a recording system, the audio signal is divided into two channels, 2.3 MHz and 2.
Each 8 MHz audio carrier is FM modulated by two audio channel signals. For video signals, the sync chip is 7.6MHz, the pedestal level is 8.1MHz, and the white peak is 9.3M.
The frequency is converted to become Hz. Then, the audio signal is further processed by PCM (Pulse Code Modulation).
) Is digitized by a modulation method such as) and converted into a pulse train signal.

This pulse train signal is, for example, EFM (Eigh
The signal is suitable for recording by the t to Fourteen Modulation method, and the frequency spectrum is 3T to 11
It becomes a frequency component of a pulse train having a width of T. here,
T indicates the bit period of the PCM signal. A 3T pulse is about 720 KHz, and a maximum width 11T pulse is about 200.
It is KHz. Such a pulse train signal is superimposed on the video main carrier at a level of about 1/10 or less, and is slice-amplified near the zero cross point to be a pulse width modulated signal, which is a recording signal.

R obtained from a recording disk on which a video signal and an audio signal are recorded by the above recording method
The frequency spectrum of the F (high frequency) signal is as shown in FIG. In FIG. 1, a component A is a digitized audio signal component, a component B is an audio FM signal component, a component C is a color information component in a video FM component, and a component D is a video FM signal. It is a luminance information component.

Since the dynamic range of the digitized audio signal can be set to about 90 dB or more, the sound quality can be remarkably improved as compared with the recording / reproducing of the audio signal by the FM modulation method. As described above, in the case of the LDD, it is possible to record and reproduce a plurality of information signals of different modulation methods. Therefore, by selecting various information contents of these information signals and recording / reproducing them by appropriately combining these, It is hoped that the development of a video disc capable of reproducing in various ways, which was not possible with the LD of, will be possible.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and an E signal that carries a recorded video format signal and an FM signal that carries a CD format signal.
It is an object of the present invention to provide a recording / reproducing system capable of reproducing by automatically determining the combination mode of each reproduction output of FM signals.

[0008]

A recording / reproducing system according to the present invention is characterized in that a video based on a video format signal obtained from a demodulated signal is superimposed on a video based on a CD format signal and displayed.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. 2 to 5 are block diagrams showing an embodiment of a recording disc information reproducing apparatus according to the present invention. Such a reproducing device is a so-called compatible player capable of reproducing CD, LD and LDD. This player has
Since the video discs (LD, LDD) and the digital audio discs (CD) have different reproduction speeds,
An LD and LDD rotation drive spindle motor 1 and a CD rotation drive spindle motor 2 are provided. These spindle motors 1 and 2 are selected according to the type of disc to be reproduced, and are switched by a switching mechanism 4 having a motor 3 as a drive source, for example.

In order to detect the disc size of the disc 5 to be reproduced, for example, three detection sensors 6, 7 and 8 are provided corresponding to the disc size in the disc radial direction. The disc size is about 5 inches (12 cm) in the case of a CD, and it is a video disc (LD, L
In the case of DD), there are two types of outer diameter, 8 inches and 12 inches. The outputs of the three detection sensors 6, 7 and 8 are waveform-shaped by the waveform shaping circuit 9 and then supplied to the disc discriminating circuit 10. For example, an optical sensor is used as the detection sensor, but the detection sensor is not limited to this.

The disc discriminating circuit 10 discriminates which of the three types of discs CD, LDD and LD is to be reproduced based on the detection outputs of the detection sensors 6, 7 and 8. FIG. 3 shows a specific circuit configuration of the disc discriminating circuit 10. In the figure, in the case of a CD, the disc size is determined to be the minimum (12 cm), and the detection output of the innermost detection sensor 6 and the inverted outputs of the detection sensors 7 and 8 passing through the inverters 79 and 80 are set as three inputs. The output of the AND gate circuit 78 becomes the CD discrimination information. That is, when the detection sensor 6 is on and the other detection sensors 7 and 8 are off, it is discriminated as a CD.
In the case of a video disc, since the disc sizes are 8 inches and 12 inches, the detection output of the detection sensor 7 or 8 is supplied to the AND gate circuit 7 via the OR gate circuit 69.
One input for each of 0 and 71. A frame synchronization detection signal generated when a frame synchronization signal is detected by a frame synchronization detection circuit 21, which will be described later, is input to the other input of the AND gate circuit 71 and is inverted by the inverter 72 to be output to the other of the AND gate circuit 70. It also serves as an input. When the detection output of the detection sensor 7 or 8 is generated and the frame synchronization detection signal is input, the AND gate circuit 71 outputs L
The LD discrimination information is output from the AND gate circuit 70 when the DD discrimination information is output and the frame synchronization detection signal is not input. These pieces of discrimination information are used to drive the indicator 11 that displays the type of disc and as switching signals for various switches described later.

A pickup 12 for reading recorded information from the disk 5 is carried by a slider base (not shown) movably provided in the radial direction of the disk 5, and the slider base is a slider motor, a reduction gear or the like. Is driven by a drive mechanism (not shown). Recording disk 5 by pickup 12
The read information read from is supplied to the digital information demodulation system 14, the analog audio demodulation system 15 and the video demodulation system 16 via the RF amplifier 13. RF
The amplifier 13 has a wide band of about 5 KHz to 14 MHz, and a single amplifier reproduces a PCM audio signal and a reproduction F.
It is possible to amplify the M audio signal and the reproduced video signal.

The digital information demodulation system 14 is provided with a changeover switch 17 that switches according to the type of the reproduction disc. This switch 17 is used in the case of LDD based on the disc information from the disc discriminating circuit 10 described above. Switch to the a side and, in the case of a CD, to the B side. That is, the signal processing system for the reproduced digital signal is switched between the LDD reproduction and the CD reproduction. When playing a CD, the playback RF output is PCM audio information,
This PCM audio information is MTF (Modulation Trans) for which the equalizer 18 compensates for a particularly high frequency range.
fer Function) compensation is given.

On the other hand, in the case of the LDD, the PCM audio information included in the reproduction RF signal together with the FM audio information and the FM video information, that is, the CD format signal is extracted by the LPF (low pass filter) 19 and supplied to the de-emphasis circuit 20. To be done. The PCM audio information is, for example, an EFM signal, but if the digital signal is directly superimposed on the FM-modulated video signal during recording, the digital signal component will be disturbed by the low-frequency component of the FM video signal. , Low-frequency components are boosted and recorded. Therefore, during playback,
On the contrary, the low-frequency component boosted at the time of recording is compensated by the de-emphasis circuit 20. As a result, the S / N ratio of the digital signal can be improved with respect to low frequency noise during recording and reproduction.

The same effect can be obtained by turning ON / OFF the power supply to the circuits of each signal processing system instead of switching the signal processing system using the changeover switch 17. The reproduced EFM signal that has passed through the changeover switch 17 is supplied to the EFM demodulation circuit 22 via the frame synchronization detection circuit 21 and also to the reproduced clock extraction circuit 23, depending on the reproduced clock extracted by the reproduced clock extraction circuit 23. The EFM demodulation circuit 22 demodulates into a PCM digital signal. This demodulated signal is written to the memory 24 such as a RAM (random access memory) under the control of the memory controller 25. At this time, the memory controller 25 is synchronized with the write clock which is the frequency-divided output of the reproduction clock frequency divider 26. Write.

To read the stored information from the memory 24, P
VCO in LL (Phase Locked Loop) circuit
The oscillation output of the (voltage controlled oscillator) 27 is synchronized with a read clock obtained by dividing the oscillation output by the divider 28. The PLL circuit has a phase comparator (P / C) 31 having two inputs, that is, the VCO 27, the frequency-divided output of the reproduced clock frequency divider 29 and the frequency-divided output of the oscillation output of the VCO 27 by the frequency divider 27. It is composed of an LPF (low-pass filter) 32 which receives the comparison output and a changeover switch 33 which selectively supplies the output voltage of the LPF 32 and the reference voltage Vref 1 to the VCO 27.

In the PLL circuit, the changeover switch 3
3 is based on the discrimination result of the disc discriminating circuit 10 described above, the output voltage of the LPF 32 is on the a side during the LDD reproduction, and is switched to the b side during the CD reproduction and the reference voltage Vref ₁
Are supplied to the VCO 27. As a result, the read clock for reading the stored information from the memory 24 during the LDD reproduction is in phase synchronization with the reproduction clock by the PLL circuit, and during the CD reproduction, the loop switch 5 to be described later will be described.
When 9 is turned on (closed), the output of the phase comparator 31 drives the CD rotation drive spindle motor 2 through the LPF 77, and the reproduction clock is phase-synchronized with the fixed clock obtained by the VCO 27 whose bias is fixed. Will be done.

The digital signal thus read is D
/ A (digital / analog) converter 34 converts into an analog audio signal, LPF 35L, 35R
Left and right playback audio output via. Memory 24
The usage status in the memory is constantly monitored by the memory controller 25, and when the memory 24 overflows from the controller 25 or becomes blank (no data exists), information indicating these states is supplied to the voltage generator 36. During LDD reproduction, the voltage generator 36 outputs a positive control voltage when the memory 24 overflows or a blank control voltage when the memory 24 overflows according to the information indicating the usage status of the memory 24 from the memory controller 25. A negative control voltage is generated, superposed on the output voltage of the LPF 32, and supplied to the VCO 27 via the changeover switch 33 to control the frequency of the read clock.

As described above, the amount of data stored in the memory 24 is constantly monitored, and when the capacity and the processing capacity of the memory 24 become excessive or insufficient, a positive or negative control voltage is generated and P
By requesting the LL circuit to deal with it, the memory 24
Can always be maintained in a normal state. In the analog audio demodulation system 15, a BPF (bandpass filter) 3 that allows only the audio carrier components of 2.3 MHz and 2.8 MHz to pass from the reproduced RF signal.
The outputs of 7L and 37R are FM-demodulated in FM demodulators 38L and 38R, and de-emphasis circuits 39L and 3L.
Left and right playback audio output is provided via 9R.

In the video demodulation system 16, only the video information of the reproduced RF signal is extracted by the BPF & notch circuit 40. In this BPF & notch circuit 40, the EFM component and 2.3 MHz included in the reproduction RF signal at the time of LDD reproduction,
It is designed to actively remove the audio carrier component of 2,8 MHz. This extracted information is sent to the limiter circuit 4
1 to the FM demodulator 42 for FM demodulation.
The demodulated output is supplied to the dropout compensator (DOC) 44 via the LPF 43, and the compensator 44 performs dropout compensation. The dropout compensator 44 is, for example, an HPF (high pass filter) 45.
An analog switch that is turned off by a detection output of a dropout sensor (DOS) 46 that detects a dropout based on a reproduction RF signal supplied via the switch, and is provided between the switch output end and a reference potential point. And a hold capacitor. Therefore, when a dropout occurs, the output level of the LPF 43 immediately before the output of the dropout sensor 46 is held and sent to the next-stage circuit to perform dropout compensation. The output of the dropout compensator 44 becomes the video output.

The output of the dropout compensator 44 is also supplied to the horizontal sync separation circuit 47 to separate and output the horizontal sync signal. This horizontal synchronizing signal is supplied to the phase comparators 48 and 49, and the phase difference from the reference signal output from the reference signal generator 50 is detected. The output of the phase comparator 48 becomes one input of the adder 51, and the output of the phase comparator 49 becomes the other input of the adder 51 via the equalizer amplifier 52. The output of the adder 51 drives the LDD and LD rotation driving spindle motor 1 via an equalizer amplifier 53 and a driver 54. This is the spindle servo system. The output of the equalizer amplifier 52 drives an actuator (not shown) built in the pickup 12 via a loop switch 55, a changeover switch 56 and a driver 57. By driving this actuator, the light spot for reading information is displaced in the tangential direction of the recording track of the disc. This is the tangential servo system. Incidentally, the actuator may be a tangential mirror for displacing the information reading light spot in the tangential direction of the recording track of the disc by rotating, or the lens may be displaced in a direction perpendicular to the optical axis. Accordingly, the information reading light spot may be deviated in the tangential direction of the recording track of the disc.

The loop switch 55 is turned on (closed) in response to the spindle lock signal output from the spindle lock detection circuit 58 when the lock of the spindle servo system is substantially completed. That is, at the start of reproduction, the spindle motor 1 is first driven by the output of the phase comparator 48 to perform coarse adjustment of the time axis (spindle servo).
When the spindle servo lock is substantially completed, the loop switch 55 is turned on, the actuator is driven by the output of the phase comparator 49, and the time axis is finely adjusted (tangential servo). According to this, the tangential servo system can remove the residual jitter component that cannot be removed by the spindle servo system.

However, even in the tangential servo system, the mechanical system such as the actuator driving mechanism cannot sufficiently follow the high frequency component of the residual jitter, so that the jitter cannot be completely removed. Therefore, in the digital information demodulation system 14 described above, the cutoff frequency of the LPF 32 of the PLL circuit that generates the read clock is set lower than the maximum frequency of the band of the tangential servo loop to cut the high frequency component of the residual jitter. As a result, the residual jitter component can be removed. More preferably, by setting the cutoff frequency of the LPF 32 lower than the eccentricity frequency of the disc (30 to 8 Hz in the case of LDD), it is possible to completely eliminate the jitter caused by the eccentricity of the disc.

Although the spindle servo and the tangential servo are performed based on the horizontal synchronizing signal, the same effect can be obtained even if the spindle servo and the tangential servo are performed based on the color subcarrier of 3.58 MHz included in the reproduced FM video signal. To be The above is the servo system during reproduction of the video disk (LDD, LD), but during reproduction of the CD, spindle servo is performed based on the output of the phase comparator 31 in the digital information demodulation system 14 described above. That is, the output of the phase comparator 31 is turned on (closed) during CD reproduction.
The spindle motor 2 for driving the CD rotation is driven through the loop switch 59 and the driver 60 in the state.
Conventionally, the above-mentioned tangential servo has not been performed during CD reproduction, but since the spindle motor 2 cannot sufficiently follow the high frequency component of the output signal of the phase comparator 31 which is a time axis error signal, this embodiment is performed. In the example, HP
The high frequency component of the time axis error signal extracted by F61 also employs a servo that drives an actuator in the pickup 12 via the changeover switch 56 and the driver 57, that is, a tangential servo. The change-over switch 56 is switched to the a side when the LDD and LD are reproduced and to the b side when the CD is reproduced, based on the discrimination result of the disc discriminating circuit 10.

Although the tangential servo during CD reproduction is performed based on the divided output of the reproduction clock extracted by the reproduction clock extraction circuit 23, the frame synchronization signal detected by the frame synchronization detection circuit 21. Even if it is performed on the basis of the frequency division output, the same effect can be obtained because the frame synchronization signal and the reproduction clock have a synchronous relationship.

The output of the spindle lock detection circuit 58 is inverted by the inverter 62, and becomes one input of the OR gate circuit 63 as a spindle unlock signal indicating that the spindle servo system is not in the locked state. The other input of the OR gate circuit 63 is supplied with a random access information signal generated at the time of a random access command such as scan, search, or jump. The LDD information output from the disc discriminating circuit 10 is also input to the OR gate circuit 63. The output of the OR gate circuit 63 is supplied to the recovered clock extraction circuit 23 via the control command circuit 64.

FIG. 4 shows a specific circuit configuration of the reproduction clock extraction circuit 23. In the figure, the reproduced EFM signal is output from the phase comparator 65 to the VCO (voltage controlled oscillator) 66.
, The phase difference with the oscillation output is detected, and the phase difference signal is L
It is supplied to the VCO 66 via the PF 67 and the changeover switch 68. As described above, the PLL that generates the reproduction clock
The circuit is configured.

The changeover switch 68 is normally on the a side and is L
The output of the PF 67 is supplied to the VCO 66. When a command signal is output from the control command circuit 64 described above, the control signal is switched to the b side in response to this command signal and the predetermined reference voltage Vref ₂ is supplied to the VCO 66. That is, when the spindle servo is not locked, or when scanning, searching,
When the information reading light spot performs a track jumping operation by a random access command such as a jump, the VCO 6
By applying the reference voltage Vref ₂ to 6 and fixing the oscillation frequency to a value close to the reproduction clock frequency, the reproduction clock is locked in after the spindle servo is locked or the random access command is released. Can be accelerated.

2 to 5, the audio output section is provided with a pair of left and right output terminals 73L and 73R of an analog audio output system and a pair of left and right output terminals 74L and 74R of a digital audio output system. There is. The audio output from the analog audio demodulation system 14 is supplied to the output terminals 73L and 73R. This audio output is also supplied to the output terminals 74L and 74R via the changeover switch 75 during LD reproduction. The changeover switch 75 is, for example, on the a side when the LD reproduction is in a normal state, and is switched to the b side based on the disc discrimination information from the disc discrimination circuit 10 during the LDD and CD reproduction. The audio output from the digital information demodulation system 14 is supplied to the output terminals 74L and 74R through the left and right mode changeover switches 76L and 76R and the changeover switch 75.

As a result, at the time of LD reproduction, the output terminal 73
Normal audio signals are output from the L and 73R and the output terminals 74L and 74R, high-quality audio signals are output from the output terminals 74L and 74R during LDD and CD playback, and are also output from the output terminals 73L and 73R during LDD playback. A normal audio signal will be output. The mode changeover switches 76L and 76R are provided to change over the output mode of the audio signal of the digital audio system at the analog stage. That is, when the audio output from the digital audio demodulation system 14 is stereophonic, the output mode described above is acceptable. For example, in the case of voice multiplexing, the L (left) channel is Japanese and the R (right) channel is foreign. The mode changeover switch 76L, which operates independently of each other,
By 76R, the sound output from the output terminals 74L and 74R can be switched to three output modes of Japanese and foreign languages, only Japanese and only foreign languages. The mode changeover switches 76L and 76R are driven separately according to control information from an operation unit (not shown).

As the mode changeover switches 76L and 76R, independently operating relays are used. Normal,
A relay having one movable contact and two fixed contacts is sufficient for signal switching, but in the present embodiment, one more relay is used.
Relays with extra moving contacts and two fixed contacts are used. That is, to describe the L-channel side relay 76L as an example, two sets of movable contacts s ₁₁ and s ₂₁ and two sets of movable contacts s ₁₁ and s that interlock with each other.
_{It is} composed of two sets of fixed contacts s ₁₂ , ₁₃ , s ₂₂ and ₂₃ provided for each pair of ₂₁ and two of the two fixed contacts s ₁₂ , s _{23 which} are the most distant from the two fixed contacts have two signals ( The left and right audio signals) are input ends, and one movable contact s ₁₁ is an output end. According to this, since there are two gaps between the left and right signal lines, it is possible to reliably prevent crosstalk between the left and right signals. It goes without saying that crosstalk can be more reliably prevented by further increasing the number of contacts and providing a large number of gaps.

In the case of the LDD, since a plurality of information signals having different modulation systems can be recorded and reproduced, 2 channels of digital audio system and 2 channels of analog audio system can be recorded.
It is possible to reproduce in various modes by selecting each information content of the channel and using it in various combinations. As a method of using the digital audio system, for example
A stereophonic channel, two analog audio channels in two languages, and a stereo bilingual movie or the like, a digital audio two channel stereo karaoke, and two analog audio channels as a singer's voice. Hi-fi karaoke playback mode, 2 channels of digital audio system as high difficulty questions and answers, 2 channels of analog audio system as high difficulty questions and answers (combinations are free) and multi-purpose, multi-purpose educational system Aspects and the like are possible.

As a method of using the combination of the video output and the audio (4 channels) output, the digital audio system is used as the digital information of the digitized image information, and the characters are superposed on the image and displayed and output. A reproduction mode, a reproduction mode in which audio and text are output as a commentary of a video, and a reproduction mode in which 2-channel video (1-channel still image) and 4-channel audio are output in combination can be considered.

In order to specify these reproduction modes, an identification signal defining each reproduction mode is required. This identification signal is recorded on a recording disk together with each information signal and read at the time of reproduction, whereby each information signal is automatically reproduced in a reproduction mode corresponding to the identification signal. When the identification signal is inserted in the digital information, the user's bit (for example, an empty channel such as the Q channel) in the subcode portion of the CD format or the TOC (Table of the Lead-in area of the disc).
Contents) and when inserted in video information, it is inserted in the vertical blanking period of the video format.

FIG. 8 shows a control circuit for controlling the audio output system based on the identification signal inserted in the vertical blanking period of the video format, for example. In the figure, a timing generation circuit 80 which receives the horizontal synchronization signal from the horizontal synchronization separation circuit 47 (shown in FIGS. 2 to 5).
Generates a timing signal based on the horizontal synchronization signal and supplies it to the identification signal extraction circuit 81. The identification signal extraction circuit 81 extracts the identification signal included in the video output from the video demodulation system 16 (shown in FIGS. 2 to 5) in synchronization with the supplied timing signal. Reproduction mode determination circuit 82
Determines the reproduction mode based on the identification signal extracted by the identification signal extraction circuit 81, and controls the audio output system to reproduce each information signal in the reproduction mode.

Although not shown in the drawing, the disk 5
Of course, a focus servo system for controlling the position of the pickup 12 in the direction perpendicular to the disc surface and a tracking servo system for controlling the position of the pickup 12 in the disc radial direction are also provided, and in these servo systems, the video disc ( It is preferable to switch the signal processing system of the error signal between the reproduction of the LDD, LD) and the reproduction of the digital audio disk (CD), and good servo can be performed regardless of the kind of the reproduced disk.

The digital signal recorded on the CD or the LDD includes not only audio information and digitized image information but also digitized control information for computer control.

[0038]

As described above, according to the recording / reproducing system of the present invention, at least an FM signal carrying a video format signal and an EFM signal carrying a CD format signal including a digital video signal are frequency-multiplexed and recorded. A recording / reproducing system for reproducing by using a video format signal obtained by demodulating an FM signal in a read signal in the reproducing process, and an EF in the read signal.
For example, since a character image obtained based on the CD format signal obtained by demodulating the M signal is superimposed and displayed, it can be conveniently used for displaying lyrics when playing karaoke software.

[Brief description of drawings]

FIG. 1 shows a frequency spectrum of an RF signal obtained from a recording disk in which a signal obtained by frequency-modulating a video signal and an audio signal and a signal obtained by PCM-modulating an analog signal by PCM are superimposed and recorded. Fig.

FIG. 2 is a block diagram showing an embodiment of a recording disc information reproducing apparatus according to the present invention.

FIG. 3 is a block diagram showing an embodiment of a recording disc information reproducing apparatus according to the present invention.

FIG. 4 is a block diagram showing an embodiment of a recording disc information reproducing apparatus according to the present invention.

FIG. 5 is a block diagram showing an embodiment of a recording disc information reproducing apparatus according to the present invention.

FIG. 6 is a block diagram showing a specific circuit configuration of the disc discrimination circuit in FIGS. 2 to 5.

FIG. 7 is a block diagram showing a specific circuit configuration of the recovered clock extraction circuit in FIGS. 2 to 5.

FIG. 8 is a block diagram of a control circuit that controls a reproduction mode.

[Explanation of symbols for main parts]

 1 LD, LDD Spindle Motor 2 CD Spindle Motor 5 Recording Disc 10 Disc Discrimination Circuit 12 Pickup 14 Digital Information Demodulation System 15 Analog Audio Demodulation System 16 Video Demodulation System 22 EFM Demodulation Circuit 23 Playback Clock Extraction Circuit 25 Memory Controller 27, 66 Voltage controlled oscillator 37, 48, 49, 66 Phase comparator 38, 42 FM demodulator 44 Dropout compensator 52, 53 Equalizer amplifier 76L, 76R Mode selector switch 84 Character generator

Claims (1)

[Claims] 1. A recording / reproducing system for frequency-multiplexing and recording at least an FM signal carrying a video format signal and an EFM signal carrying a CD format signal including a digital video signal, and reproducing the same. A frequency multiplexed signal including the FM signal and the EFM signal is read, the frequency multiplexed signal is separated into the FM signal and the EFM signal, and the FM signal and the EFM signal are respectively demodulated to obtain the video format signal and the CD format signal. And extracting the digital video signal from the CD format signal, superimposing an image based on the digital video signal on an image based on the video format signal, and displaying and outputting the superimposed image.