JPS63214983A - Random music selecting system in disk reproducing device - Google Patents

Abstract

PURPOSE:To attain a random reproduction continuously even when the number of musics is few by reading at least all the number of the musics from at time code, preventing the same music from being selected within a predetermined protecting range preset according to the number of the musics and varying the protecting range according to all the number of the musics. CONSTITUTION:At the time of reproducing a disk set in a disk reproducing device, at least all the number of the musics is read from the time code as accumulating totals recorded in a read in part. At the time of executing the random music selection, the music of the same music number is not reproduced in the protecting range determined according to the number of the musics and the protecting range is varied according to the number of all the musics. Thereby, even when the number of the musics is few, the random reproduction is carried out.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a disc playback device that prevents the same track number from being played for a certain number of tracks when an operator selects a random track during playback of a disc. This paper relates to a random music selection method.

[Conventional technology and its problems]

When an operator randomly selects a song on an optical disk, for example, a compact disk, a random number is generated within the processor, and the appropriate song number is selected and played sequentially. but,
Even if random playback is performed using random numbers generated within the processor, the generated random numbers may cause the same song to be played continuously, or the same song may be played again after playing several songs, etc. There were problems such as random playback sometimes not being performed.

[Purpose of the invention]

The present invention aims to solve the above-mentioned problems.In random playback, the same song is prevented from being played within a predetermined protection range according to the number of songs, thereby making it possible to perform substantial random playback. It is an object of the present invention to provide a random music selection method in a disc playback device, in which the protection range is made variable according to the total number of songs, and continuous random playback can be performed even when the number of songs is small.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention provides T.

At least the total number of songs is read from C, and when random songs are selected, the same song is prevented from being played within a protection range determined according to the number of songs, and the protection range is changed according to the total number of songs. The purpose of this is to make it variable.

[Embodiments of the invention]

Next, a case in which an embodiment of the present invention is applied to a disc playback device that selects and plays one disc from a magazine containing a large number of discs will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a magazine that stores N (N is a natural number of 2 or more) disks arranged in order at a predetermined pitch. The magazine 1 is provided with N trays for carrying disks in a housing that protrudes from the magazine body. The magazine 1 is detachably attached to a predetermined attachment portion. One of the N disks D, ~Ds stored on N trays each serving as a plurality of disk storage positions provided in the magazine 1 is transferred to the rotating shaft of the spindle motor 3 by the disk ejecting and conveying mechanism 2. It is conveyed and clamped onto the disk supporting surface of the turntable 4 to which it is fixed. The disk ejecting and transporting mechanism 2 includes a protruding member that protrudes the tray of the magazine l and moves the disk onto the disk supporting surface of the turntable 4, and a protruding member that causes the disk to move onto the disk supporting surface of the turntable 4. It has a clamp mechanism that clamps the disk, a moving plate that changes the relative position of this protruding member with respect to the magazine l in the tray arrangement direction, and a sensor that detects the position of the moving plate, the operation of the clamp mechanism, etc. ing. This disk ejection transport mechanism 2
By moving the movable plate in , the position of the protruding member changes, making it possible to select a disc. These magazines 1 and disk ejecting transport mechanism 2
The structure is detailed in Japanese Patent Application No. 153651/1983.

Recorded information on the disk Dn, which is taken out from the magazine 1 by the disk ejecting and conveying mechanism 2 and clamped onto the disk supporting surface of the turntable 4, is read by the optical pickup 6. The pickup 6 includes a laser diode, an objective lens, a focus actuator, a tracking actuator, a photodetector, and the like.

The output of the pickup 6 is supplied to each of a focus servo circuit 7, a tracking servo circuit 8, and a reproduction clock generation circuit 9 including an RF amplifier.

In the focus servo circuit 7, a focus error signal is generated by, for example, an astigmatism method, and a focus actuator in the pickup 6 is driven in accordance with this error signal. As a result, the laser light emitted from the laser diode and passed through the objective lens is focused on the recording surface of the disk Dn, forming an information detection light spot. Further, in the tracking servo circuit 8, a tracking error signal is generated by, for example, a push-pull method, and this error signal is sent to the tracking actuator in the pickup 6 and the carriage servo circuit 10. The output of the carriage servo circuit 10 is supplied to a motor Ma that drives a carriage (not shown) carrying the pickup 6, and the pickup 6 is sent in the radial direction of the disk Dn.

A reproduced clock signal for demodulation is generated in the reproduced clock generation circuit 9 and supplied to the spindle servo circuit 11. In the spindle servo circuit 11, a drive signal according to the phase difference between the reproduced clock and the reference clock from the clock generation circuit 12 is generated to drive the spindle motor 3, and control the track linear velocity of the disk Dn to be constant. be done. Further, the output of the RF amplifier in the reproduced clock generation circuit 9 is supplied together with the reproduced clock to an EFM demodulation circuit 13 including a frame synchronization circuit. The demodulated output of the EFM demodulation circuit 13 is processed by a data processing circuit 14 that performs deinterleaving, error detection, correction, correction, etc. of the demodulated data signal.

Thereafter, the demodulated output is temporarily stored in a data memory 15, read out using a clock signal from a clock generation circuit 12, and converted into an analog signal by a D/A (digital/analog) converter 16. This analog signal is output as left and right audio signals via an LPF (low pass filter) 17 and an amplifier 18. Furthermore, amplifier 18
is configured to receive control data and change its frequency characteristics in accordance with the control data.

On the other hand, the control signal in the data from the EFM demodulation circuit 13 is supplied to the system controller 20, and during the song,
Various information such as song intervals, song numbers, playing times, and disc model numbers are read. The system controller 20 is formed of one or more microcomputers including a processor, ROM (read-only memory), RAM (random access memory), an interface circuit, a timer, and the like. In this system controller 20, a processor is stored in advance in the ROM and operates according to a program based on the flowchart shown in FIG. The output data is processed to supply various commands and data to the carriage servo circuit 10, spindle servo circuit 11, amplifier 18, display 22, and drive circuits 24 and 25. The random number generation circuit 23 is configured, for example, to latch and output the output of an m-ary counter (where m is a natural number) whose coefficient values sequentially change in extremely short cycles in response to a data output command. In addition, the drive circuit 24.25
are configured to supply driving currents according to commands to motors Mb and Mc that respectively drive the moving plate and the protruding member in the disk ejecting and transporting mechanism 2.

Note that 26 is a RAM that stores information from the system controller 20.

S l-S a is various detection switches arranged near the magazine 1 installed in a predetermined mounting part, S is a magazine detection switch that sends out an output when the magazine 1 is mounted in a predetermined mounting part; S, is a disk detection switch that detects the presence or absence of a disk in the ejected tray; S, is a tray detection switch that detects whether or not a tray is stored in the magazine 1; S4 is a switch that moves up and down with respect to the turntable 4; This is a magazine position detection switch that detects the position of the magazine 1.

Next, the operation of the processor in the system controller 20 will be explained with reference to the flowchart of FIG.

First, when the power is turned on, the processor monitors whether the magazine 1 is set in the predetermined mounting section or not.Step a)
, when magazine 1 is attached to a predetermined attachment part and magazine detection switch S detects the set of magazine l and sends the detection signal to the processor, the processor detects magazine l.
determines that is set and proceeds to the next step, and
If it is not attached, the operation will stop.

In the next step, the magazine 1 is moved up and down to place the magazine 1 in a position where the top or bottom tray can be pulled out (step b), and the magazine position detection switch S4 receives the position signal of the magazine 1. Once sent to the processor, the processor proceeds to the next step.

In the next step, it is detected whether or not there is a disk in the tray to be pulled out.In step C), when the disk detection switch S2 detects a disk, it is determined that there is a disk, and this operation is performed for all disks. Step forward.

In the next step, the processor monitors whether the playback switch is turned on or not (step d), and if it is not detected that the playback switch is turned on, the process waits for the playback switch to be operated, and the playback switch is turned on. When operated and turned on, the processor outputs a signal for loading a disc to the playback device. Therefore, the playback device loads the disc (step e).
, rotates the disc and jumps the pickup to the lead-in portion of the disc (step f).

At this time, the processor monitors whether the pickup has been lead-in or not (step g), and if the pickup has not been lead-in, returns to the previous step f, and if lead-in is confirmed, proceeds to the next step.

In the next step, the TOC is read (step h), and the processor stores at least the total number of songs T in the memory in reading the TOC (step i).
Then, the processor judges the memory contents, that is, whether the total number of songs is 1 or 2. (Step j) If the total number of songs is up to 2, there is no need for random song selection, so the protection range is Instead, set the random constant to O and proceed to the next step (step k).

On the other hand, if it is determined in step j that the total number of songs is three or more, a random constant R is determined according to the total number of songs (step l). That is, in this example,
Since the protection range is limited to a maximum of 8 songs, the random constant R-
Calculate by total number of songs + 2.

For example, if the total number of songs is ≧16, it will be set to R-8, and the same song will be protected from being played for eight songs during random playback, which will be described later.

After determining the random constant in this manner, the processor monitors whether or not an instruction for random reproduction is given by the operator (step m). If the random playback instruction is not given, the process proceeds to step U and normal playback starts from the first song. When the random reproduction instruction is detected, the random constant R determined in step i is generated, and the generated random number value is stored in P (n) (step n). and,
After the step n, the processor monitors whether the step has no protection range, that is, R-0 (step 0), and if there is no protection range, proceeds to step r and calculates P (n1 Search for songs.

On the other hand, in step 0, if it is detected that there is a need for a protection range, that is, R≠0, the processor determines whether the random number generation value P (n) is a song that has been played so far. Monitoring step p), random number generation value P (n)
If it is the same as one song in the R times of the previous playback, return to step n and perform random number generation again.
If it is different from one song in the R rotation, proceed to the next step. In the next step, monitor whether the random number generation value P (n) is the second song played in the R rotation. If it is a played song, step n is performed in the same way as step p.
If the song is different from the played song, the process proceeds to the next step, and the operation of monitoring whether it is the third song as described above is repeated R times (step q).

As a result of repeating the above operations, if the selected random number generation value P (n) has not been reproduced in the past R times of reproduction, the processor searches for the song number of the random number generation value P (n) ( step r), then monitors whether the search has ended or not; step S); when detecting that the search has ended, updates the information in the memory (step t); and when the update is completed, the random number generation value is P(
n) (step u) e As mentioned above, when random playback is instructed, the processor plays the song with random number generation value P (n) within a preset protection range. It operates so as not to be played, starts playing, and ends its operation.

〔Effect of the invention〕

As described above, the present invention reads at least the total number of songs from the TOC, and when random songs are selected, prevents the same song from being played within a predetermined protection range depending on the number of songs, In addition to making it possible to perform substantially random playback, the protection range is made variable according to the total number of songs, so that continuous random playback can be performed even when the number of songs is small.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a disc playback device used in the present invention, and FIG. 2 is a flowchart according to the present invention. 1...Magazine, 2...Disc ejection transport mechanism, 2
0...System controller, Sl...Magazine detection switch, S2...Disk detection switch, S...
...Tray storage detection switch, S4...Magazine position detection switch.

Claims (1)

[Claims] When playing a disc set in a disc playback device, at least the total number of songs is read from the cumulative time code (TOC) recorded in the lead-in section, and if random songs are selected, the number of songs with the same number is read. A random song selection method for a disc playback device, characterized in that a song is not played back during a protection range determined according to the number of songs, and the protection range is varied depending on the total number of songs.