JPH01102775A - Disk reproducing device - Google Patents

Abstract

PURPOSE:To shorten the reproducing time of index information and to offer convenience on an operation by switching reproducing speed to the maximum reproducing speed in the reproducing state of the index information of a disk, automatically. CONSTITUTION:The title device is to reproduce the disk 12 on which an information signal and its index information are recorded in differenct recording area, respectively, and the device switchable the reproducing speed by switching the rotating speed of the disk 12 is set as an object. And the reproducing speed is automatically switched to the maximum reproducing speed out of the switchable reproducing speed in the reproducing state of the recording area of the index information. In such a way, it is possible to shorten the reproducing time of the index information and to offer the convenience on the operation to a user.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a disc playback device capable of switching the playback speed, and in particular to shortening the playback time of index information recorded on the disc. Regarding what you choose to do.

(Prior Art) As is well known, in a disc playback device such as a compact disc player, the recording time is determined in consideration of recording the played analog audio signal on another recording medium such as a tape. In order to shorten the standard 2
Some devices are now appearing that have a function that allows them to play back at twice the speed. However, this type of disc playback device is still in the development stage, and the optimal playback has been determined for playback at standard speed and playback at twice the standard speed. There is still a lot of room for improvement in terms of configuration and performance, such as making it easier to operate and making it easier to handle by making active use of the playback function at twice the standard speed. It is something.

(Problems to be Solved by the Invention) As described above, conventional disc playback devices that lack the ability to play at twice the standard speed are still not able to fully meet the needs of users. The problem is that there is no.

Therefore, this invention has been made in consideration of the above circumstances, and by automatically switching to the fastest playback speed when the index information of the disc is being played, the playback time of the index information can be shortened and handling can be made convenient. The purpose is to provide an extremely good disc playback device.

[Structure of the Invention] (Means for Solving the Problems) That is, since the disc playback device according to the present invention plays back a disc in which an information signal and its index information are recorded in different recording areas, The target is a device in which the playback speed can be changed by changing the rotational speed of the disc.

The apparatus is configured to automatically switch to the highest playback speed among the switchable playback speeds in the playback state of the index information recording area.

(Function) According to the above configuration, since the playback speed is automatically switched to the highest speed in the index information playback state, the playback time of the index information can be shortened, making handling easier for the user. It can be made convenient.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 11 denotes a disk reproducing mechanism section, which includes a disk table 14 on which the disk 12 is placed and rotationally driven by the action of a disk motor 13, and a disk reproducing mechanism section 11.
an optical pickup 15 that reads digital data recorded on the disk 2; and a pickup feed motor 1 that moves the optical pickup 15 in the radial direction of the disk 12.
It consists of 6.

Then, the reproduction R output from the optical pickup 15
The F signal is sent to the current-voltage conversion amplifier circuit 17. ia, an analog amplifier circuit 2 consisting of a wideband RF amplifier circuit 19 and a feedback circuit 20 that determines the characteristics of the wideband RF amplifier circuit 19;
1 and then supplied to the servo control circuit 22.

This servo control circuit 22 receives input reproduction R.
The F signal is level-sliced at a predetermined slice level and converted into digital data, and a disk motor control signal and a pickup feed motor control signal are generated based on this digital data.

Of these, the disk motor control signal is supplied to the disk motor 13 via a drive circuit 25 consisting of an amplifier circuit 23 and a feedback circuit 24, and its rotational speed is controlled. Further, the pickup feed motor control signal is supplied to the pickup feed motor 16 via the drive circuit 26, and the optical pickup 1
The moving speed of 5 is controlled by υ.

Note that within the analog amplifier circuit 21, a tracking error signal and a focus error signal are generated. Of these, the tracking error signal is supplied to the optical pickup 15 via a drive circuit 29 consisting of an amplifier circuit 27 and a feedback circuit 28, and tracking servo is performed for an objective lens (not shown). Further, the focus error signal is supplied to the optical pickup 15 via a drive circuit 32 consisting of an amplifier circuit 30 and a feedback circuit 31, and focus servo for the objective lens is performed.

Here, the servo control circuit 22 uses a phase locked loop circuit (PLL) based on the generated digital data.
) 33 to generate a bit synchronization clock.

Then, the servo control circuit 22 generates a data extraction signal based on the bit synchronization clock, and outputs it to the digital signal processing circuit 34 along with the digital data.

This digital signal processing circuit 34 is provided with a crystal oscillator 35 and is synchronized with a system clock output from an O-clock generation circuit 36.
7 is used to perform jitter component absorption, error correction, and correction processing on digital data. The digital data output from this digital signal processing circuit 34 is then transferred to a D/A (digital/analog) conversion circuit 38.
The signal is converted into an R channel analog signal and supplied to an audio reproduction system (not shown) via amplifier circuits 39 and 40 and output terminals 41 and 42, respectively.

Here, this compact disc player has:
A reproduction speed control circuit 43 is provided.

When the disc 12 is required to be played back at twice the standard playback speed, the playback speed control circuit 43 controls the Mizushima oscillator 35 and the phase-locked loop circuit 33 to operate at a frequency twice the standard speed. The system clock and bit synchronization clock of each feedback circuit 2 are controlled to be generated.
Wideband RF amplifier circuit 19 for 0.24.28.31
．． This functions to switch the characteristics of the drive circuits 25, 29, and 32 so that they are optimal for reproduction at twice the standard speed.

The playback speed control circuit 43 also has the function of causing the display circuit 44 to display the operating status, time, etc. of the compact disc player.

Here, the system clock output from the clock generation circuit 36 is supplied to the cassette tape recorder 46 via the digital signal processing circuit 34 and the synchronization control circuit 45. This cassette tape recorder 46 is of a type in which the tape running speed during recording and reproduction changes in synchronization with the system clock, that is, the recording and reproduction speed changes.

Therefore, when the disc 12 is being played back at the standard speed, the system clock is also at the standard frequency, so if the cassette tape recorder 4G is set to the recording state, the recording speed will also be the standard, and the output terminals 41 and 42 will The output acoustic signal is now recorded on the tape at standard speed. Furthermore, when the disc 12 is being played back at twice the standard speed, the system clock is also at twice the standard frequency, so if the cassette tape recorder 46 is set to recording mode, the recording speed will also be twice the standard speed. Therefore, output terminal 4
The sound signal output from 1°42 is recorded on the tape at twice the standard speed.

In the above configuration, the features of the present invention will be explained below with reference to the flowcharts shown in FIGS. 2 and 3. First, when the start (step 31) is started, in step S2, it is determined whether or not the tray switch that is turned on when the tray (not shown) that accommodates the disc 12 reaches the disc playback position is in the on state. is determined.

And if the tray switch is not on (No)
, In step S3, the tray motor is driven to move the tray to the disc playback position.

In this case, in step S4, it is determined whether an overcurrent has flowed through the tray motor, that is, whether the movement of the tray to the disc playback position has been forcibly blocked by an external force.

Here, if no overcurrent flows to the tray motor (N
o>, the process returns to step S2, and if an overcurrent is flowing through the tray motor (YES), the drive of the tray motor is stopped in step S5, and the tray is moved to the open position, for example, as shown in step S6. Such processing is performed.

If the tray switch is on (YES) in step S2, the tray motor is braked in step S7 to prevent the tray from being inadvertently moved from the disc playback position. Finally, in step S8, it is determined whether a start limit switch (not shown), which is turned on when the optical pickup 15 reaches the innermost side of the disk 12, is turned on.

If the start limit switch is on (YES), the pickup feed motor 16 is driven in step S9 to move the optical pickup 15 toward the outer circumference of the disk 12, and the process returns to step S8. Further, if the start limit switch is not in the ON state in step S8 (No), in step S810,
The optical pickup 15 is moved toward the inner circumference of the disk 12 by driving the pickup feed motor 16.

This movement of the optical pickup 15 toward the inner circumference of the disk 12 is continued until it is determined in step 511 that the start limit switch is turned on again. Then, in step S11, if the start limit switch is in the on state (YES), step 31
2, the pickup feed motor 16 is stopped to stop the movement of the optical pickup 15.

After that, in step S13, the playback speed control circuit 43:
A mode in which playback is performed at twice the standard speed (hereinafter referred to as double speed mode) is set, and in step S14, the servo system including the servo control circuit 22 and the data processing system including the digital signal processing circuit 34 are compatible with the double speed mode. The state is set to

Then, in step S15, gain adjustment of the focus servo is performed, and in step 316, a focus search is performed to move the objective lens to the vicinity of the in-focus position. Thereafter, in step 817, it is determined whether the objective lens has reached the vicinity of the in-focus position, that is, whether the focus is OK.

Here, if focus is not OK (No), focus search is performed again in step 318. The focus search in step 818 is performed in step 81.
9, the process continues until a predetermined time period elapses. If the focus is not OK within a predetermined time (YES), in step 820, processing corresponding to when the disk 12 is not mounted or when the disk 12 is mounted upside down is performed.

Also, in step S17, if the focus is OK (Y
ES), in step 821, it is determined whether the CRC code data for error correction is correct.

If it is not correct (No), the process returns to step S19, and if it is correct (YES), it is determined in step S22 whether or not it is the lead-in area of the disc 12.

Here, if it is not the lead-in area (NO), the pickup feed motor 16 is driven in step S23 to move the optical pickup 15 toward the inner circumference of the disk 12, and the process returns to step 317.

If it is a lead-in area (YES), in step 824 TOC (Table of Contents) data in the lead-in area is read in double speed mode.

Thereafter, in step 825, it is determined whether reading of the TOC data has been completed. Then, if the playback speed control circuit 43 is not finished (No), the process returns to step 819, and if it is finished (YES), the playback speed control circuit 43 is set to the standard speed mode in step S27.
Then, it is determined whether or not there is a search request.

Here, if there is no search request (No), step 82
At step 8, the device enters a standby state, and when the playback operator is operated, for example, the playback state returns to the standard speed. If there is a search request (YES), a predetermined search process is performed in step 8.29.

According to the configuration of the above embodiment, the TOC data is automatically read in the double speed mode when the disc 12 is loaded, so the time required to read the TOC data can be shortened, and the user It can be convenient for handling.

As is well known, the TOC data includes information such as the minimum song number recorded on the disc 12, the maximum song number recorded on the disc 12, the total performance time, and the absolute start time of each individual performance.
This index data is repeated frame by frame to complete one cycle. That is, one cycle of TOC data can be expressed as (number of recorded songs + 3) x 3, and it can be seen that the greater the number of recorded songs, the longer one cycle becomes.

And in a compact disc player, disc 12
When the TOC data is loaded, the TOC data is automatically read and the device enters a standby state for search operations, etc.

Therefore, in this invention, by using the double speed playback function, the TO
By playing back the C data at double speed, the time required to play back the TOC data is shortened, making it more convenient for the user.

Furthermore, recently, compact disc players have been introduced which allow a plurality of discs to be set and the designated songs of the designated discs to be sequentially played back in a programmed manner. In the case of such a player, first, TOC data of a plurality of loaded discs are sequentially read to cope with program playback.

For this reason, reading TOC data at standard speed as in the past would take a very long time, but reading TOC data at double speed can significantly shorten the time it takes to read TOC data. , is particularly suitable for this type of player.

It should be noted that the present invention is not limited to the above-mentioned example, but can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] Therefore, as detailed above, according to the present invention, by automatically switching to the fastest playback speed in the playback state of the index information of the disc, the playback time of the index information is shortened and the handling is made easier. It is possible to provide an extremely convenient disc playback device.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing an embodiment of a disc reproducing apparatus according to the present invention, and FIGS. 2 and 3 are flowcharts for explaining the operation of the embodiment. 11... Disk playback mechanism section, 12... Disk,
13... Disc motor, 14... Disc table, 15... Optical pickup, 16... Pickup feed motor, 17.18... Current-voltage conversion amplifier circuit, 19... Broadband RF amplification Circuit, 20... Feedback circuit, 21... Analog amplifier circuit, 22... Servo control circuit, 23... Amplifier circuit, 24...
Feedback circuit, 25.26 drive circuit, 27... amplifier circuit,
28...Feedback circuit, 29...Drive circuit, 30...
Amplifying circuit, 31... Feedback circuit, 32... Drive circuit,
33... Phase locked loop circuit, 34... Digital signal processing circuit, 35... Crystal oscillator, 36... Clock generation circuit, 37... RAM138... D/A conversion circuit, 39.40 ... Amplification circuit, 41.42 ... Output terminal, 43 ... Playback speed control circuit, 44 ... Display circuit, 45 ... Synchronization control circuit, 46 ... Cassette tape recorder. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] In a disc playback device for playing back a disc in which an information signal and its index information are recorded in different recording areas, and in which the playback speed can be switched by switching the rotational speed of the disc, the recording area of the index information is 1. A disc playback device comprising a switching means for automatically switching to the highest playback speed among switchable playback speeds in a playback state.