JPS61120375A - Reproducing device for magnetic disk - Google Patents

Abstract

PURPOSE:To simplify circuit constitution and to display video information on a cathode-ray tube at low cost even during CD reproduction by converting the video information on a CD into a video format signal and then outputting it by using a video output line for an LD in common. CONSTITUTION:A reference synchronizing signal generating circuit 87 generates synchronizing signals corresponding to a horizontal and a vertical synchronizing signal, and they are supplied to the other input of a changeover switch 86 and one input of a changeover switch 91 and also sent to a graphic generator 92 which inputs a demodulated digital signal. The changeover switch 91 inputs the output of the graphic generator 92 and supplies its output to one input of a changeover switch 88. A demodulated video signal is supplied to the other input of the changeover switch 88. A selection switch 83 and the changeover switches 86 and 88 are all placed at sides (a) in LD reproduction and at sides (b) in CD reproduction. The changeover switch 91 is normally at a side (a) and switched to a side (b) when CD reproduction including digitized video information is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION 11L" The present invention relates to a recording disc information reproducing apparatus, and more particularly to a reproducing apparatus for reproducing recorded information on a recording disc on which digital signals are recorded.

As recording discs on which digital signals are recorded, there are known digital audio discs on which audio signals are subjected to predetermined digital modulation processing and pulse train formation, that is, so-called compact discs (hereinafter abbreviated as CDs), and more recently At the same time, a video disc is recorded using a method (see Japanese Patent Application No. 58-45780) in which a pulse train signal obtained by digitizing an audio signal using a predetermined digital modulation method is superimposed on each FM modulated signal of a video signal and an audio signal. (hereinafter abbreviated as LDD) has been developed.

In this recording system, the audio signal is made into two channels, and the 2.3 MHz and 2.8 MHz audio carriers are each FM-modulated by two audio channel signals. In addition, the video signal has a sync chip of 7°6MH2 and a pedestal level of 8.
．． The frequency is converted so that the frequency is 1MHz7 and the whitebeak is 9.3MHz. Then, the audio signal is further converted into PCM (Pulse Coda Modulat).
The signal is digitized and converted into a pulse train signal using a modulation method such as ion).

This pulse train signal is, for example, an EFM (Eight to
1”ourteenMOdLIlatiOn’)
Depending on the method, the signal is suitable for recording, and the frequency spectrum is a frequency component of a pulse train having a width of 3T to 11T. Here, T indicates the bit period of the PCM signal, and the 3T pulse is approximately 720 KHz, and the maximum width 11T pulse is approximately 200 KHz. Such a pulse train signal is approximately 1
The signal is superimposed at a level of /10 or lower, slice-amplified near the zero-crossing point, and becomes a pulse-width modulated signal, which is used as a recording signal.

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

Since the dynamic range of the digitized audio signal can be approximately 90 dB or more, the sound quality can be significantly improved compared to recording and reproducing audio signals using the FM modulation method.

Furthermore, video discs (hereinafter referred to as LDs) are already known in which digital signals are not recorded, but video signals and audio signals are frequency-modulated and recorded, and these discs can be played by a single playback device. If it can be regenerated, it will be very advantageous in terms of economy and usability, and it will also be extremely convenient.

By the way, in the case of a CD, it is possible to record and play not only audio information but also video information using subcodes. According to this, for example, a picture of the jacket can be projected on the screen and you can enjoy the music while looking at it. It is possible. When considering a playback device that can also play video discs, a cathode ray tube is essential, so if the cathode ray tube can also display the video information of the CD during CD playback, the cathode ray tube can be used effectively.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a recording disc information reproducing device that can display CD video information on an LD diode cathode ray tube with a simple circuit configuration and low cost. shall be.

A recording disk information reproducing apparatus according to the present invention includes a first recording disk on which a video signal and an audio signal are respectively recorded after being modulated in a predetermined manner, and a second recording disk on which predetermined information is recorded after being subjected to a predetermined digital modulation process and converted into a pulse train. A recording disk information reproducing device capable of reproducing a recording disk and outputting digitized video information included in a demodulated digital signal obtained by demodulating a signal read from a second recording disk as a video format signal. and a selection means for selectively outputting the demodulated video signal obtained by demodulating the signal read from the first recording disk and the video format signal,
A feature of the present invention is that the output of this selection means is a video output.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 is a block diagram showing an embodiment of a recording disc information reproducing apparatus according to the present invention. Such a playback device is a CD
, LD, and LDD. This Play V includes video discs (LD, LDD) and digital audio discs (C
Since D) and C have different reproduction rotational speeds, etc., a spindle motor 1 for driving LD and LDD rotation and a spindle motor 2 for driving CD rotation are provided. These spindle motors 1 and 2 are selected depending on the type of disc to be played.
For example, switching is performed by a switching mechanism 4 using a motor 3 as a driving source.

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 for CDs is approximately 5 inches (1
2cn+), and in the case of video discs (LD, LDD), there are two types of outer diameters: 8 inches and 12 inches. The outputs of the three detection sensors 6 , 7 and 8 are waveform-shaped by a waveform shaping circuit 9 and then supplied to a disk discrimination circuit 10 . As the detection sensor, for example, an optical sensor is used, but the detection sensor is not limited to this.

The disc discrimination circuit 10 determines whether the disc to be played is CD1LDD based on the detection outputs of the detection sensors 6.7 and 8.
It is determined which of the three types of disks, LD and LD. A specific circuit configuration of this disk discrimination circuit 10 is shown in FIG. In this diagram, in the case of CD,
The disk size is determined to be the minimum (12cn+),
The detection output of the innermost detection sensor 6 and the inverter 79.
The output of the AND gate circuit 78 which converts the inverted output of the detection sensor 7.8 which has passed through the detection sensor 80 into three-man power becomes the CD discrimination information. That is, the detection sensor 6 is on and the other detection sensors 7.8
When it is off, it is separated from CD by ≠1. 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 passes through the OR gate circuit 69 and becomes the output of each of the AND gate circuits 70 and 71. In addition, a frame synchronization detection circuit 2 to be described later
A frame synchronization detection signal generated when a frame synchronization signal is detected from 1 becomes an input of an AND gate circuit 71, and is also inverted by an inverter 72 and becomes an input of an AND gate circuit 70. and detection sensor 7 or 8
When a detection output is generated and a frame synchronization detection signal is input, the AND gate circuit 71 outputs LDD discrimination information, and when the frame synchronization detection signal is not input, the AND gate circuit 70 outputs LD discrimination information. . This discrimination information is used to drive an indicator 11 that displays the type of disc, and as a switching signal for various switches to be described later.

A pickup 12 for reading recorded information from the disk 5 is supported by a slider base (not shown) that is movable in the radial direction of the disk 5, and the slider base is driven by a slider motor, a reduction gear, etc. driven by a mechanism (not shown). Read information read from the recording disk 5 by the pickup 12 is supplied to a digital information demodulation system 14, an analog audio demodulation system 15, and a video demodulation system 16 via an RF amplifier 13, respectively. The RF amplifier 13 has a wide band of about 5 KHz to 14 MHz, and a single amplifier can amplify a reproduced PCM audio signal, a reproduced FM audio signal, and a reproduced video signal.

The digital information demodulation system 14 is provided with a changeover switch 17 that changes depending on the type of disc to be reproduced.
Based on the disc information from , it switches to the A side in the case of an LDD, and to the B side in the case of a CD. That is, L.D.D.
The signal processing system for the reproduced digital signal is switched between reproduction and CD reproduction. During CD playback, the playback RF output is PCM audio information, and this PCM audio information is converted into M TF (M 0 duration T
ransrer)"unction) compensation is applied.

On the other hand, in the case of LDD, FM audio information and FM
PCM audio information included in the reproduced RF signal together with the video information is extracted by an LPF (low pass filter) 19 and supplied to a de-emphasis circuit 20. PCM
Audio information is, for example, an EFM signal, but if a gain signal is directly superimposed on an FM-modulated video signal during recording, the digital signal component will be interfered with by the low-frequency component of the FM video signal. -Low frequency components are boosted and recorded. Therefore, during reproduction, the de-emphasis circuit 20 performs compensation by dropping the low-frequency components boosted during recording. This makes it possible to improve the S/N ratio of the digital signal with respect to low frequency noise during recording and reproduction.

Note that instead of switching the signal processing system using the changeover switch 17, the power supply to each signal processing system circuit is set to 0N.
A similar effect can be obtained by using 10FF.

The reproduced εFM 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 is also supplied to the reproduced clock extraction circuit 23. The EFM demodulation circuit 22 demodulates the signal into a PCM digital signal.

This demodulated signal is written into a memory 24 such as a RAM (random access memory) under the control of a memory controller 25, but at this time, the memory controller 25 is synchronized with the write clock which is the frequency-divided output from the frequency divider 26 of the reproduced clock. Do a read-in.

Reading of stored information from the memory 24 is performed in synchronization with a read clock obtained by dividing the oscillation output of a vCO (voltage controlled oscillator) 27 in a PLL (phase locked loop) circuit by a frequency divider 28. It has become so. The PLL circuit is the aforementioned VCO
27. Frequency division output by frequency divider 29 of reproduced clock and VC
A phase comparator (P/C) 31 that uses the divided output of the oscillation output of the O27 and the frequency divided output by the frequency divider 27, an LPF (low pass filter) 32 that receives this comparison output as input, and this L
It is constituted by a changeover switch 33 that selectively supplies the output voltage of the PF 32 and the reference voltage Vref+ to the CO 27.

In the PLL circuit, the changeover switch 33 is set to the a side during LDD playback and switches the output voltage of the PF 32 to the b side during CD playback, and switches the reference voltage yrer1 to the VCO.
Supply to 27. As a result, during LDD playback, the read clock for reading stored information from the memory 24 is set to P.
The phase of the reproduced clock is synchronized by the LL circuit, and when a loop switch 59 (described later) is turned on (closed) during CD playback, the output of the phase comparator 31 becomes LP.
By driving the spindle motor 2 for driving the CD rotation through F77, the reproduced clock is phase-synchronized with the fixed clock obtained by the VCO 27 whose bias is in a fixed state.

The digital signal thus read out is converted into an analog audio signal by a D/A (digital/analog) converter 34, and then sent to an LPF 35L.

35R to become left and right playback audio outputs.

The usage status in the memory 24 is constantly monitored by the memory controller 25, and when the memory 24 overflows or becomes blank (no data), the controller 25 sends information indicating these statuses to the voltage generator 3.
Supply to 6. During LDD regeneration, this voltage generator 36
generates a positive control voltage when the memory 24 overflows, and generates a negative control voltage when the memory 24 becomes blank, according to information indicating the usage status of the memory 24 from the memory controller 25, The frequency of the read clock is controlled by superimposing it on the output voltage of the LPF 32 and supplying it to the VCO 27 via the changeover switch 33.

In this way, the amount of data stored in the memory 24 is constantly monitored by FfF, and when there is an excess or deficiency in the capacity and processing capacity of the memory 24, a positive or negative control pressure is generated and the PLL is activated.
By requesting the circuit to take such action, the memory 24 can always be maintained in a normal state.

In the analog audio demodulation system 15, only the audio carrier V components of 2.3 MHz and 2.8 MH2 are passed through from the reproduced RF signal. ．．
The signal is FM demodulated at 38R, and becomes left and right playback audio outputs via de-emphasis circuits 39L and 39R.

In the video demodulation system 16, only video information is extracted from the reproduced RF signal by a BPF & notch circuit 40. This BP
In the F&notch circuit 40, the 5, FM components and 2.3 MHz, 2.
8M)-1z audio key components are actively removed. This extracted information is passed through the limiter circuit 41 to FM! ! 1 unit 42 and is FM demodulated. This demodulated output is supplied to the dropout compensator (DQC>44 via the LPF 43, and the compensator 44
Dropout compensation is provided. This dropout compensator 44 includes, for example, a dropout sensor (DO) that detects dropouts based on a reproduced RF signal supplied via an HPF (bypass filter) 45.
8) It is composed of an analog switch that is turned off by the detection output of 46, and a hold capacitor provided between this switch output terminal and a reference potential point.

Therefore, when a dropout occurs, the level of the output of the LPF 43 immediately before the output of the dropout sensor 46 is held and sent to the next stage circuit, thereby performing dropout compensation. This dropout compensator 4
The output of 4 becomes the video output.

The output of the dropout compensator 44 is sent to the horizontal sync separation circuit 4.
7, and the horizontal synchronizing signal is separated and output. This horizontal synchronizing signal is supplied to phase comparators 48 and 49, and the phase difference with the reference signal output from the reference signal generator 50 is detected. The output of the phase comparator 48 serves as an input to the adder 51, and the output of the phase comparator 49 supplies the equalizer amplifier 5.
2 to the adder 51. The output of the adder 51 is the equalizer amplifier 53 and the driver 5.
4, the spindle motor 1 for driving the LDD and LD rotation is driven. This is the spindle servo system. Further, the output of the equalizer amplifier 52 drives an actuator (not shown) built into the pickup 12 via a loop switch 55, a changeover switch 56, and a driver 57.

By driving this actuator, a light spot for reading information is IIM-directed in the tangential direction of the recording track of the disk. This is the Tangential Chibo series. Note that the actuator may be a tangential mirror that rotates to shift the optical spot for reading information in the tangential direction of the recording track of the disk, or a tangential mirror that displaces the lens in a direction perpendicular to the optical axis. The optical spot for information reading may be biased in the tangential direction of the recording track of the disk.

The loop switch 55 is turned on (opened) in response to a spindle lock signal output from the spindle lock detection circuit 58 when locking 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), and when the locking of the spindle servo is almost completed, The loop switch 55 is turned on, and the phase comparator 4
The actuator is driven by the output of 9, and fine adjustment (tangential adjustment) of the time axis is performed. According to this, residual jitter components that cannot be removed by the spindle servo system can be removed by the tangential servo system.

However, even in the tangential chibo system, jitter cannot be completely removed because the mechanical system such as the actuator drive mechanism cannot sufficiently follow the high-frequency components of residual jitter. Therefore, in the digital information demodulation system 14 mentioned above, the PL that generates the read clock is
The residual jitter component can be removed by setting the cutoff frequency of the LPF 32 of the L circuit to be lower than the maximum frequency of the band of the tangential mevoloop to cut the high frequency component of the residual jitter. More preferably, by setting the cutoff frequency of the LPF 32 lower than the eccentric frequency of the disk (30 to 8H2 in the case of LDD), it is possible to completely eliminate jitter caused by the center of the disk.

The spindle servo and tangential servo were performed based on the horizontal synchronization signal, which was 3.58 MHz included in the reproduced FM video signal.

A similar effect can be obtained even if it is performed based on color subcarriers.

The above is a servo system when reproducing a video disc (LDD, LD), but when reproducing a 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 drives the spindle motor 2 for driving the CD rotation via the loop switch 59 which is turned on (open) during CD reproduction and the driver 60. Conventionally, the above-mentioned tangential servo was not performed during CD playback, 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 In the example, HPF6
The high frequency component of the time axis error signal extracted by 1 is
A servo, that is, a tangential servo, is also used to drive the actuator in the pickup 12 via the changeover switch 56 and driver 57. The changeover switch 56 is switched to the a side when reproducing L'DD and L'D, and to the b side when reproducing a CD, based on the determination result of the disc discriminating circuit 10.

15. Tangential servo during CD playback is performed based on the divided output of the reproduced clock extracted by the reproduced clock extraction circuit 23, but the frame synchronization signal detected by the frame synchronization detection circuit 21 Even if it is based on the frequency-divided output of the frame synchronization signal and the reproduced clock, the same effect can be obtained.
The signal is inverted at , and becomes the sole power of the OR gate circuit 63 as a spin and dollar unlock signal indicating that the spindle servo system is not in the locked state.

As the output of the OR gate circuit 63, a random access information signal generated at the time of a random access command such as search, search, jump, etc. is supplied. Furthermore, the LDD information output from the disk discrimination 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.

A specific circuit configuration of the recovered clock extraction circuit 23 is shown in FIG. In this figure, the reproduced EFM signal is transmitted to the phase comparator 6.
5, a phase difference with the oscillation output of a VCO (voltage controlled oscillator) 66 is detected, and the phase difference signal is supplied to the VCO 66 via an LPF 67 and a changeover switch 68. As described above, a PLL circuit that generates a reproduced clock is configured.

The changeover switch 68 is normally located on the a side and supplies the output of the LPF 67 to the VCO 66, but the control command circuit 6 described above
When a command signal is output from 4, it switches to the b side in response to this command signal and supplies a predetermined reference voltage Vrerz to the VCO 66.

That is, when the spindle servo is not in a locked state or when the information reading light spot jumps tracks due to a random access command such as a scan, search, or jump, the reference voltage Vref2 is applied to the VCO 66 to reproduce its oscillation frequency. By fixing the clock frequency to a value close to the clock frequency, it is possible to hasten the lock-in of the recovered clock after the spindle servo is locked or after the random access command is released.

Referring again to FIG. 2, the audio output section includes a pair of left and right output terminals 73L and 73R of the analog audio output system.
A pair of left and right output terminals 74L and 74R of a digital audio output system are provided. Output terminal 73L,
The audio output from the analog audio demodulation system 14 is supplied to 73R. This audio output is sent to output terminals 74L and 74 via a changeover switch 75 during LD playback.
It is also supplied to R. The changeover switch 75 is located on the a side when playing an LD, for example, as a normal state.

When playing a CD, the switch is switched to the b side based on the disc discrimination information from the disc discrimination circuit 10. The audio output from the digital information demodulation system 14 is supplied to the output terminals 74L, 74R via the left and right mode changeover switches 76L, 76R and the changeover switch 75.

As a result, during LD playback, the output terminal 73L.

Normal audio signals are output from 73R and output terminals 741.74R, and during LDD and CD playback, high quality audio signals are output from output terminals 74L and 74R, and when LDD is played back, normal audio signals are output from output terminals 73L and 73R. An audio signal will be output.

The mode changeover switches 76L and 76R are provided to change over the output mode of digital audio audio signals in an analog stage. In other words, if the audio output from the digital audio demodulation system 14 is stereophonic, the above-mentioned output mode will suffice, but in the case of audio multiplexing, for example, the L (left) channel may be Japanese and the R (right) channel may be the same. A mode selector switch 76L that is in a foreign language and operates independently of each other;
76R allows the audio output from the output terminals 74L and 74R to be switched to three output modes: Japanese and foreign languages, Japanese only, and foreign languages only. The mode changeover switches 76L and 76R are driven separately according to control information from an operation section (not shown).

Relays that operate independently are used as the mode changeover switches 76L and 76R. Normally, a relay with one movable contact and two fixed contacts is sufficient for signal switching, but in this embodiment, a relay with one movable contact and two extra fixed contacts is used. is used. That is, if we take the relay 761 on the L channel side as an example, there are two sets of movable contacts 5 that interlock with each other.
ur821 and these two sets of movable contacts SI1. Two sets of fixed contacts 512, one pair for each S21. +31
5η, 23, the two fixed contacts SI2.323 that are the most distant among the two sets of fixed contacts serve as input ends for the two signals (left and right audio signals), and one movable contact S
I+ is the output terminal. According to this, since two gaps exist between the left and right signal lines, crosstalk between the left and right signals can be reliably prevented. Of course, crosstalk can be more reliably prevented by increasing the number of contacts and providing more gaps.

The demodulated digital signal demodulated by the EFM demodulation circuit 22 includes data such as total time, remaining time, number of tracks, etc., and is inserted into the Q channel of the user's bit, for example. On the other hand, various data are also inserted into the demodulated video signal demodulated by the FM demodulation circuit 42, for example, within the vertical blanking period, and the data (Q information) is separated by a Q information separation circuit 90 and becomes another input to the selection switch 83. The data selected by the selection switch 83 is supplied to a character generator 84.

The sync separation circuit 85 separates horizontal and vertical signals included in the demodulated video signal.
The vertical synchronization signal is separated and made available to the changeover switch 86 alone. The reference synchronization signal generation circuit 87 generates a synchronization signal corresponding to the horizontal and vertical synchronization signals, and inputs the other inputs of the changeover switch 86 and the changeover switch.

It is supplied to the graphics generator 92 which inputs the demodulated digital signal.

The changeover switch 91 receives the output of the graphic generator 92 as an input, and outputs the output from the changeover switch 88 . A demodulated video signal is supplied as the other input to the changeover switch 88. The selection switch 83 and changeover switches 86 and 88 are both switched to side a during LD playback and to side b during CD playback. The selector switch 91 is normally located on the a side, and is switched to the b side when a CD containing digitized video information is played back.

During LD playback, the character generator 84 synchronizes with the horizontal and vertical synchronization signals from the synchronization separation circuit 85, and also generates C
During D reproduction, data output from the selection switch 83 is converted into character (including symbols) information in synchronization with the synchronization signal from the reference synchronization signal generation circuit 87. That is, the character generator 84 is used for both LD playback and CD playback. The output of character generator 84 is supplied to adder 89. An adder 89 adds horizontal and vertical synchronizing signals to the character information from the character generator 84 and outputs it as a video output.

According to this configuration, the Q information can be displayed on a cathode ray tube (not shown) when a CD is played back, and the cathode ray tube can be used effectively. In addition, the character generator 84
Since this is shared for CD playback and LD playback, the circuit configuration can be simplified and realized at low cost.

Furthermore, in the case of a CD, it is possible to record and reproduce not only audio information but also subcode-processed video information (still images), and this video information is inserted into the subcode section. When playing a CD that includes this video information, you should command the playback mode accordingly (command signal input from the operation unit or TOC (Ta) in the lead-in area of the CD, for example).
The selector switch 91 is switched to the b side in accordance with the identification signal inserted in the ble orContcnts) position. The digitized video information included in the demodulated digital signal is converted into a video format signal by adding horizontal and vertical synchronization signals from the reference signal generation circuit 87 in the graphic generator 92 and becomes a video output. LD via changeover switches 91 and 89
The light is supplied to a cathode ray tube (not shown), and an image is formed on the screen thereof.

As a result, it is possible to enjoy music, for example, while looking at a picture of a jacket displayed on the screen, or in the same way as a famous album. In addition, the CRT can be used as a CD.
Since the circuit configuration is simple and can be used in common with the LD and the LD, it can be realized at low cost.

Although not shown in the figure, a focus servo system that controls the position of the pickup 12 relative to the disk 5 in a direction perpendicular to the disk surface, and a tracking servo system that controls the position of the pickup 12 in the disk radial direction are also naturally provided. Therefore, even in these servo systems, it is preferable to switch the signal processing system for error signals between when playing a video disc (LDD, LD) and when playing a digital audio disc (CD).
Good servo can be performed regardless of the type of disc being played.

In addition, the digital signal recorded on CD or LDD is
In addition to audio information and digitized image information, it also includes control information for computer control.

As described in detail of the invention, according to the recording disc information reproducing apparatus according to the present invention, the video information included in the CD is converted into a video format signal and then outputted by sharing the video output line for LD. , the circuit configuration can be simplified, and the video information can be displayed on the cathode ray tube even when playing a CD at low cost.

[Brief explanation of drawings]

Figure 1 shows the frequency spectrum of an RF multiplied signal obtained from a recording disk recorded by superimposing a signal obtained by frequency modulating a video signal and an audio signal, and a signal obtained by PCM modulating an analog signal and making it into a pulse. 2 is a block diagram showing an embodiment of the recording disc information reproducing apparatus according to the present invention, FIG. 3 is a block diagram showing a specific circuit configuration of the disc discrimination circuit in FIG. 2, and FIG. FIG. 2 is a block diagram showing a specific circuit configuration of the reproduced clock extraction circuit in FIG. 2, and FIG. 5 is a block diagram showing a character information generation section and a CD video information output section. Explanation of symbols of main parts 1...Swiss spindle motor 2 for LD and LDD
...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

Claims (2)

[Claims] (1) A first recording disk on which a video signal and an audio signal are respectively modulated and recorded in a predetermined manner, and a second recording disk in which predetermined information is subjected to a predetermined digital modulation process and recorded as a pulse train can be reproduced. The recording disc information reproducing apparatus comprises means for outputting digitized video information included in a demodulated digital signal obtained by demodulating a signal read from the second recording disc as a video format signal; A selection means for selectively outputting a demodulated video signal obtained by demodulating a signal read from one recording disk and the video format signal, and the output of the selection means is a video output. A recording disc information reproducing device. (2) The recording disk information reproducing apparatus according to claim 1, wherein the second recording disk also includes video information.