JP2716781B2 - Disc player - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a disc player capable of playing different kinds of discs.

BACKGROUND ART There is a CD (Compact Disc) as a disc recorded in a format including only a digital audio signal in a predetermined band, and a format including an analog audio signal in another band different from the predetermined band. There is a video disc as a recorded disc. Further, among video disks, there is a so-called LDD disk in which digital audio signals and analog audio signals are recorded in a format including the above-mentioned predetermined band and other bands.

The frequency spectrum of the RF signal obtained from such an LDD disk is as shown in FIG. In FIG. 4, the spectrum of the audio signal of the left and right two channels in which the component of the predetermined band indicated by A is digitized, the component indicated by B is the spectrum of the audio FM signal of the left and right two channels, and the component indicated by C is the video FM signal. Spectrum.

By the way, in each of the different types of disks having different recording formats, particularly in the case of a karaoke disk, the content of one channel signal of the recorded left and right two-channel audio signals becomes monaural accompaniment, and the content of the other channel signal. Is a predetermined two-channel monaural recording system in which singing sound is used in addition to monaural accompaniment. In the case of the above-mentioned LLD disc, an analog audio signal is usually a signal of such a predetermined two-channel monaural recording system, and a digitized audio signal is a signal having a content related to the content of the analog audio signal. It is recorded as a stereo audio signal. However, depending on the disc, a digital audio signal may be recorded in a predetermined two-channel monaural recording system, or both an analog audio signal and a digital signal may be recorded in a predetermined two-channel monaural recording system. In some cases, both analog audio signals and digital signals are recorded as stereo audio signals.

On the other hand, in a conventional disc player, one of a digital audio signal reproduction output and an analog audio signal reproduction output is selected in accordance with a manual operation to provide a player audio signal output. Therefore, when playing an LDD disc, there are various recording methods for analog and digital audio signals as described above. Therefore, a user must select a reproduction output and listen to the reproduced sound before a two-channel monaural reproduction is performed. It was inconvenient to know whether the video was being played or stereo playback.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a disc player capable of playing different kinds of discs, which can easily select one of two-channel monaural reproduction and stereo reproduction on an LDD disc.

A disc player according to the present invention is a disc player capable of reproducing a disc recorded in a plurality of different formats, wherein a first reproduction mode for reproducing a digital audio signal as a monaural signal and a second reproduction mode for reproducing a digital audio signal as a stereo signal. A playback unit for performing playback processing in one of a second playback mode, a third playback mode for playing back an analog audio signal as a monaural signal, and a fourth playback mode for playing back an analog audio signal as a stereo signal; Discriminating means for discriminating the format of the disc, instructing means for instructing one of stereo reproduction and monaural reproduction according to manual input, and discriminating means for discriminating means when the discrimination result of the discriminating means indicates a predetermined format. No first depending on the result A first selecting means for selecting the reproducing means as any one of the reproduction mode of the fourth reproduction mode,
When the discrimination result of the discrimination means indicates a format other than the predetermined format, one of the first to fourth reproduction modes is set as a reproduction mode in accordance with the discrimination result of the discrimination means and the command result of the command means. And a second selecting means for making a selection.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of an optical disc player according to the present invention. In this player, a disc 2 is driven to rotate by a spindle motor 1, and its recording signal is read by an optical pickup 3.
The pickup 3 is carried by a carriage (not shown) that moves in the radial direction of the disk 2 by a carriage motor 4, and the information reading point (light spot for information reading) of the pickup 3 is freely positioned in the radial direction of the disk 2. You. Further, various servo systems such as a spindle servo system, a focus servo system, a tracking servo system, and a carriage servo system are provided, but are not shown because they are already well known.

The spindle motor 1 and the carriage motor 4 are driven by a spindle servo system, a carriage servo system, or a playing section control circuit 5. The playing section control circuit 5 controls the spindle motor 1 according to a command from the system controller 7.
In addition, driving of the carriage motor 4 and on / off control of various servo systems (not shown) are performed.

The RF signal which is the read output of the pickup 3 is a band pass filter (BPF) 6 for video FM, an analog audio FM
The signal is supplied to a signal low-pass filter (LPF) 8 and a digital audio EFM signal band-pass filter 9.
The video FM signal that has passed through the video FM BPF 6 is supplied to a video demodulation circuit 10 and demodulated by the video demodulation circuit 10 to become a reproduced video signal. The passing signal of LPF8 is 2.3MHz and 2.
BP to pass only the 8MHz audio carrier component
F11L and 11R separate the left and right channels into analog audio FM signals.
The audio signal is demodulated by L and 12R to become left and right channel audio signals.

On the other hand, the digital audio EFM signal separated from the reproduced RF signal by the digital audio EFM signal BPF 9 is supplied to the EFM demodulation circuit 13 and the synchronization signal detection circuit 24. The EFM demodulation circuit 13 is configured to perform EFM demodulation processing on a pulse signal obtained by slicing an RF signal to form PCM data, that is, digital data including time-division multiplexed left and right channel audio signals and subcodes. ing. Digital data including audio information output from the EFM demodulation circuit 13 is supplied to a deinterleave / interpolation circuit 14. The synchronization signal detected by the synchronization signal detection circuit 24 is supplied to the system controller 7 and also to the deinterleave / interpolation circuit 14 as a timing signal. The deinterleave / interpolation circuit 14 cooperates with the RAM 15 to return the digital data whose order has been rearranged by the interleaving performed at the time of recording to the original state, and sends out the digital data to the error correction circuit 16.
Is configured to interpolate the error data in the output data of the error correction circuit 16 by an average value interpolation method or the like when a signal indicating that the data cannot be corrected is output. The error correction circuit 16 has a CIRC (Cross Interleave Reed Solomo
n Code), the digital data is supplied to the deinterleave / interpolation circuit 14, and if the data cannot be corrected, a signal indicating that the data cannot be corrected is output.

The output data of the deinterleave / interpolation circuit 14 is D / A
It is supplied to a (digital / analog) conversion circuit 17. D /
The A conversion circuit 17 has a demultiplexer that separates digital data including time-division multiplexed left and right channel audio information for each channel, and reproduces both left and right channel audio signals. The reproduced audio signal becomes a digital audio output after unnecessary components are removed by LPFs (low-pass filters) 18L and 18R.

The outputs of the left and right channels of the LPFs 18L and 18R are respectively connected to one fixed input of a changeover switch 19L and 19R for switching between analog and digital reproduction outputs, and each output of the FM demodulation circuits 12L and 12R is connected to the other of the changeover switches 19L and 19R. Are respectively connected to the fixed inputs. Each of the movable outputs of the changeover switches 19L and 19R is provided with a changeover switch 20 for switching between disc playback and external input.
L and 20R are connected to one fixed input. Outputs of an external input terminal EXT for receiving an audio signal from a signal source such as a tape deck are connected to the other fixed inputs of the changeover switches 20L and 20R. Selector switch 20
A variable resistor 21 as a balance adjuster is connected between each movable output of L and 20R. The mover of the variable resistor 21 is connected to the audio signal output terminal of the player via the switches 22L and 22R. Also, changeover switches 19L, 19
Each of the R movable outputs is connected to the audio signal output terminal of the player via switches 23L and 23R. Switches 19L, 19R, 20L, 20R and switches 22L, 22R, 23
ON and OFF of L and 23R are controlled by the system controller 7.

On the other hand, the subcode output from the EFM demodulation circuit 13 is
It is supplied to the system controller 7. The system controller 7 includes a microcomputer including, for example, a processor, a ROM, a RAM, a timer, and the like.
ROM, RAM by command according to key operation supplied from 28
After performing an arithmetic operation based on data or a program stored in, for example, an instruction signal such as play, search, jump, etc., is supplied to the performance section control circuit 5.

The reproduced video signal output from the video demodulation circuit 10 is supplied to the control code detection circuit 25. The control code detection circuit 25, for example, is inserted in advance during the vertical synchronization signal blanking period of the video signal that is FM modulated and recorded, and the content of the left channel analog audio signal is only monaural accompaniment, and the right channel The content of the analog audio signal includes a song in addition to the monaural accompaniment, that is, a control code representing a predetermined two-channel monaural recording system is detected to generate a detection signal composed of a high-level signal. The detection signal output from the control code detection circuit 25 is supplied to the system controller 7.

Further, a first mounting sensor 26 for detecting the mounting of the disc at a predetermined playing position and a second mounting sensor 27 for detecting the mounting of a disc having a predetermined size (for example, a diameter of 20 cm or more) are provided. , 27 are supplied to the system controller 7. The first mounting sensor 26 is provided, for example, at a position corresponding to within 6 cm in the radial direction from the center of the disk and optically detects the mounting of the disk. The second mounting sensor 27 is provided at a position corresponding to, for example, 6 cm to 10 cm in the radial direction from the center of the disk, and optically detects the mounting of the disk.

FIG. 2 shows the front surface of the disk player according to the present invention. A selection key 32 for selecting one of a disk performance and an external input is provided below a disk tray 31 for mounting a disk, and a variable resistor. An operation knob 33 of the device 21 is provided with a two-channel monaural reproduction output selection key 34 and a stereo reproduction output selection key 35. Also,
On the right side of the disc tray 31, keys such as a music selection key 36 are provided. These keys are part of the keys of the operation unit 28.

In this configuration, when the power is turned on, the processor of the system controller 7 starts operating, and first, as shown in FIGS. It is determined whether or not it has been selected (step 41). When the external input is selected, the switches 20L and 20R are switched to the external input side (step 42). When the disc performance is selected, the switches 20L and 20R are switched to the disk playing side (outputs of the switches 19L and 19R). Side) (step 43). In the case of playing a disc, it is determined whether or not the disc is mounted at a predetermined playing position (step 44). If the first disk detection signal indicating that the disk has been mounted has not been supplied from the first mounting sensor 26 to the system controller 7, this routine ends. When the first disk detection signal is supplied to the system controller 7, it is determined that the disk is mounted at the predetermined playing position and it is determined whether or not the disk is a disk of a predetermined size (step 45). When a disk of a predetermined size is mounted, the first disk detection signal is supplied from the first mounting sensor 26 and the second disk detection signal is also supplied from the second mounting sensor 27. If the second disk detection signal is not supplied, it is assumed that the mounted disk is a CD or CDV, and it is determined whether the two-channel monaural reproduction mode or the stereo reproduction mode is selected (step 46). When the two-channel monaural reproduction output selection key 34 is operated, if the two-channel monaural reproduction mode is selected, it is stored in the internal memory (not shown) of the system controller 7, and the stereo reproduction output selection key 35 is operated. In this case, if the stereo reproduction mode is selected, the data is stored in the internal memory. Therefore, the processor of the system controller 7 determines the selection mode according to the internal memory. The internal memory is 2
The description will be made assuming that the channel monaural reproduction mode is initially set. Therefore, when the 2-channel monaural reproduction mode is selected, the switches 22L and 22R are turned on and the switches 23L and 23R are turned off (step 47). When stereo reproduction is selected, the switches 23L and 23R are turned on and the switches 22L and 22R are turned off (step 47). 48). After the switches 22L, 22R and 23L, 23R are controlled, the changeover switches 19L, 19R are output to output a reproduction signal of the digital audio signal.
A digital selection operation for switching R to the digital side (the output side of LPFs 18L and 18R) is performed (step 49).

Note that the processor of the system controller 7 proceeds to step 46 after execution of step 42.

On the other hand, if it is determined in step 45 that a disc of a predetermined size is to be mounted, a command is issued to the playing section control circuit 5 to start driving the spindle motor 1 and the carriage motor 4, and the digital audio signal is output. It is determined whether or not it has been recorded (step 51). This is determined by whether or not a synchronization signal is supplied from the synchronization signal detection circuit 24. If the synchronization signal is supplied, it is a video disk on which a digital audio signal is recorded, that is, an LDD disk. If the synchronization signal is not supplied, the processor is regarded as a normal video disk and the processor of the system controller 7 determines whether or not the code detection signal is supplied from the control code detection circuit 25 (step
52). If the detection signal is supplied, the content of the left channel analog audio signal is only monaural accompaniment,
This indicates that the content of the analog audio signal of the right channel includes a song in addition to the monaural accompaniment, and that the audio signal is recorded by a predetermined two-channel monaural recording method. Therefore, when the detection signal is not supplied, the switches 23L and 23R are turned on and the switches 22L and 22R are turned off and the switches 22L and 22R are turned off in order to assume that the stereo audio signal is recorded and to set the stereo reproduction mode (step 5).
3) When the detection signal is supplied, the switches 22L and 22R are turned on and the switches 23L and 23R are turned off in order to enter the two-channel monaural reproduction mode (step 5).
Four). After the control of the switches 22L, 22R and 23L, 23R, an analog selection operation of switching the changeover switches 19L, 19R to the analog side (the output side of the demodulation circuits 12L, 12R) to output a reproduced signal of an analog audio signal is performed ( Step 5
Five). As described above, when the audio signal is regarded as a normal video disk on which only an analog audio signal is recorded, the mode designation by operating the two-channel monaural reproduction output selection key 34 and the stereo reproduction output selection key 35 is ignored. You.

For LDD discs, TOC
It is determined whether (Table of Contents) is provided (step 56). TOC is a subcode indicating the music data such as the playing time of each music recorded on the disk, the head position of the music, a stereo audio signal, and the type of the disk.
If this TOC is not provided, the process proceeds to step 52 as in the case of a normal video disc. If a TOC is provided, the TOC data is read and written into an internal memory (not shown), and it is determined from the TOC data whether a digital audio signal is recorded by a predetermined two-channel monaural recording method (step 57). . If such a digital audio signal has been recorded, it is determined whether or not a detection signal has been supplied from the control code detection circuit 25 (step 58). When the detection signal is supplied, the loaded LDD disc determines that both the digital audio signal and the analog audio signal are recorded by the predetermined two-channel monaural recording method, and
Switch 22 to enter channel monaural playback mode
L, 22R are turned on and switches 23L, 23R are turned off (step 59), and a digital selection operation is performed to switch the changeover switches 19L, 19R to the digital side in order to output a reproduction signal of a digital audio signal (step 6).
0). As described above, when both the digital audio signal and the analog audio signal are regarded as an LDD disc recorded by a predetermined two-channel monaural recording method, the two
The mode designation by operating the channel monaural playback output selection key 34 and the stereo playback output selection key 35 is ignored.

If the detection signal is not supplied in step 58, it is determined that the digital audio signal is recorded on the loaded disk in a predetermined two-channel monaural recording system and the stereo audio signal is recorded in analog, and the two-channel monaural reproduction is performed. Mode key or stereo playback mode is selected.
The determination is made according to the operation result of step 5 (step 61). This determination is the same as in step 46. When the two-channel monaural reproduction mode is selected, the switches 22L and 22R are turned on and the switches 23L and 23R are turned off (step 62), and the digital switches are switched to the digital side in order to output digital audio signal reproduction signals. The operation is performed (step 63). When stereo reproduction is selected, the switches 23L and 23R are turned on and the switches 22L and 22R are turned off (step 64), and an analog selection operation is performed in which the changeover switches 19L and 19R are switched to the analog side to output a reproduced analog audio signal. (Step
65).

If the digital audio signal of the predetermined two-channel monaural recording method is not recorded in step 57, the digital stereo audio signal is recorded on the mounted LDD disc, so that it is necessary to determine the recording method of the analog audio signal. Control code detection circuit
It is determined whether or not a detection signal is supplied from step 25 (step 66). If the detection signal is not supplied, the analog signal is also regarded as an LDD disk on which a stereo audio signal is recorded, and the switches 23L and 23R are turned on and the switches 22L and 22R are turned off (step 67). A digital selection operation of switching the changeover switches 19L and 19R to the digital side in order to output the reproduction signal of the above (step 68). Also in this case, the mode designation by operating the two-channel monaural reproduction output selection key 34 and the stereo reproduction output selection key 35 is ignored.

If a detection signal is supplied in step 66, the analog signal is regarded as an LDD disc recorded in a predetermined two-channel mono recording method and a digital audio signal is recorded as a stereo signal. It is determined which of the stereo reproduction modes is selected according to the operation result of the selection keys 34 and 35 (step 69). This determination is similar to steps 46 and 61. When the 2-channel monaural playback mode is selected, the switches 22L and 22R are turned on and the switches 23L and 23R are turned off (step 70), and the analog switches for switching the changeover switches 19L and 19R to the analog side to output analog audio signal playback signals. Perform action (step
71). When stereo playback is selected, the switches 23L and 23R are turned on and the switches 22L and 22R are turned off (step 7).
2) Perform a digital selection operation of switching the changeover switches 19L and 19R to the digital side to output a reproduction signal of a digital audio signal (step 73).

The processor of the system controller 7 repeatedly executes the above operation, and when a performance start command is generated by a key operation of the operation unit 28, the performance start operation is started according to the playback mode determined as described above, for example, by interrupt processing. You do it. In this performance start operation, a control signal is generated to the performance section control circuit 5 in accordance with the reproduction mode to rotate the disk and control the reading position of the pickup 3.

In the case of the stereo reproduction mode, the demodulation circuits 12L, 12L
The output signals of the R or LPFs 18L and 18R become the output signals of the player. In the case of the monaural reproduction mode, the audio signals of the left and right channels are mixed by the variable resistor 21.
Since the mixing ratio of the left and right channel audio signals changes depending on the position of the mover of the variable resistor 21, the level of the singing sound included in the right channel audio signal is adjusted and output.

Effect of the Invention As described above, in the disc player of the present invention,
When a manual input is made, the disc is played as a playback mode in accordance with the manual input together with the recording format of the disc. Therefore, it is easy to manually select a desired mode of the two-channel mono reproduction and the stereo reproduction on the LDD disc by the manual operation. Can be. When playing a disc of a predetermined recording format, the disc is played by setting a reproduction mode according to the recording format without following manual input. In other words, if the disc cannot be played in the playback mode selected by the manual operation, the playback mode according to the recording format of the disc is automatically set ignoring the manual playback mode. This is convenient because it is not necessary. Further, a desired mode can be arbitrarily selected from two-channel monaural reproduction and stereo reproduction even in a disk such as a CD in which the recording format of the disk cannot be determined or an external input.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the front of the player of FIG. 1, FIG. 3 is a flowchart showing the operation of a system controller in the player of FIG.
FIG. 4 is a diagram showing a frequency spectrum of each signal recorded on the LDD disk. Explanation of Signs of Main Parts 1 ... Spindle motor 3 ... Pickup 7 ... System controller 12L, 12R ... FM demodulation circuit 13 ... EFM demodulation circuit 21 ... Variable resistor

Claims (1)

(57) [Claims] 1. A disc player capable of reproducing a disc recorded in a plurality of different formats, wherein the first reproduction mode reproduces a digital audio signal as a monaural signal, and the second reproduction mode reproduces a digital audio signal as a stereo signal. Playback means for performing playback processing in one of a mode, a third playback mode for playing back an analog audio signal as a monaural signal, and a fourth playback mode for playing back an analog audio signal as a stereo signal. Discriminating means for discriminating a format; commanding means for commanding one of stereo reproduction and monaural reproduction according to a manual input; discriminating by the discriminating means when the discrimination result of the discriminating means indicates a predetermined format. The first according to the result
First selecting means for causing the reproducing means to select any one of the fourth to fourth reproducing modes as a reproducing mode; and a discriminating result of the discriminating means when the discrimination result of the discriminating means indicates a format other than a predetermined format. And a second selection means for causing the reproduction means to select any one of the first to fourth reproduction modes as a reproduction mode in accordance with a command result of the command means.