JPH0414691A - Data reproducing processor - Google Patents

Abstract

PURPOSE:To output a data from a designated target address without fail by setting a certain position, which is separated from the position of the target address in an address decreasing direction only for a prescribed distance, as a read starting position and moving a reading means to this read starting position. CONSTITUTION:When the processor of a player controller 13 receives a read command from a system controller 17, it is judged whether or not a current address according to a subcode address to be obtained from a subcode decoder 10 is coincident with the target address, and when it is decided that the current address is coincident with the target address, based on disk identification information in TOC information read from a read-in area, the light spot of a pickup 6 is jumped from the position of the target address in the address decreasing direction only for the prescribed distance. Continuously, the muting of a mute circuit 21 is canceled and afterwards, the processing is moved to a play mode.

Description

TECHNICAL FIELD The present invention relates to a data reproducing processing device, and more particularly to a data reproducing processing device that performs processing for reproducing data read from a memory disk.

BACKGROUND ART There is a CD-ROM as a storage medium of a read-only memory (ROM) for digital information, which utilizes a CD (compact disc), which has been established as a digital audio disc (hereinafter simply referred to as an audio disc). FIG. 3(A) shows the frame structure of the CD subcode, FIG. 3(B) shows the format of the subcode Q signal, and FIG. 4(A) shows the frame structure of the CD-ROM data. (B) shows the CD-ROM data format and header format, respectively.

As is clear from these figures, CD-ROki (hereinafter referred to as memory disk) has the same signal format as CD, so conventional disc players cannot use CD-ROki.
Data read from a memory disk can be reproduced by simply adding an OM decoder. That is, a disc player that reads data stored on a memory disc, and a CD-ROM that decodes data read from this disc player.
A data reproduction processing device is constituted by the ROM decoder.

In conventional disc players, a mute circuit is installed after the demodulation system that demodulates the information read from the disc.
By prohibiting the transmission of the demodulated output to the next stage using this mute circuit except in performance mode, it prevents the generation of abnormal sounds due to noise etc. when playing an audio disk, and prevents the generation of pseudo data due to noise etc. when playing a memory disk. is configured to do so.

In a data reproducing processing device equipped with such a disc player, in response to a read command from a system controller that controls the entire device, the disc player executes reading of recorded data at a target address according to the process described below. In other words, when the system controller uses header address information (hereinafter referred to as header address) to specify a target address from which to start reading data and sends a read command, the controller on the disc player side (hereinafter referred to as player controller) ) searches for the specified target address in response to the read command based on the address information in the subcode (hereinafter referred to as subcode address) obtained from the information read from the memory disk, and then enters the performance mode. Transition. When entering the performance mode, the mute circuit, which had been on until then, is turned off and the demodulated output CDROM is turned off.
Start transmission to decoder.

In this way, if you start playing from the specified target address, when you cancel mute after entering performance mode, if the timing of canceling is delayed, data will be output from the point past the target address. Sometimes. For example, when a memory disk is used as a storage medium for map data, the map data has no meaning as data unless it is read from the beginning of one map unit, so if the data is output after the target address, This will cause a problem in that the specified map cannot be displayed.

Summary of the Invention [Object of the Invention] Therefore, an object of the present invention is to provide a data reproduction processing device that can reliably output data from a specified target address when reading data from a memory disk. .

[Structure of the Invention] A data reproducing processing device according to the present invention includes a reading means for reading recorded information on a memory disk, a demodulating means for demodulating the information read by the reading means, and a decoding unit for decoding data being demodulated and output from the demodulating means. A data reproduction processing device comprising: a decoder; muting means for prohibiting transmission of the demodulated output of the demodulating means to the decoder during a control signal existence period; and means for generating the control signal during a period other than the reading period by the reading means. means for specifying a target address at which recorded data should be read from a memory disk; and means for setting a position a predetermined distance away from the target address position in an address decreasing direction as a reading start position by the reading means; The reading apparatus is configured to include means for controlling the reading means to move the reading means to the reading start position.

[Operation of the Invention] In the data reproduction processing device according to the present invention, when a target address for reading recorded data from a memory disk is specified, a reading start position is set at a position a predetermined distance away from the target address position in the address decreasing direction. , search for this reading start position, and start playing from this position.

EXAMPLE Hereinafter, an example of the present invention will be explained in detail based on the drawings.

In FIG. 1, a disc player 1 is a so-called slot-in-cube audio disc memory in which a disc (hereinafter referred to as an audio disc and a memory disc) 2 is inserted through a slot (not shown) formed on the front surface of a housing. It is a disc player. In this disc player 1, a disc 2 inserted through the slot is loaded by a loading mechanism 3, mounted on a turntable 4 serving as a playing position, and rotated by a spindle motor 5. Recorded information on the disc 2 is read by an optical pickup 6. The bi-noqua tube 6 is mounted on a slider (not shown) that moves in the radial direction of the disk 1 using a slider motor 7 as a driving source.

In the case of a CD format signal, the output signal of the pickup 6 is E F M (Eight to Fourth
n Modulation) signal, and this read EF
The M signal passes through the RF amplifier 8 and is converted into EFM by the EFM demodulation circuit 9.
After being demodulated, the error correction circuit 11 corrects the error, and the D/A converter 12 converts the signal into an analog signal and outputs it as a playback audio signal, and a part of the demodulated output is supplied to the subcode decoder 10. . The subcode decoder 10 decodes subcode information inserted in frame units, that is, code information such as the song number, index, time within the song, frame number, and absolute time and frame number within the disc. is performed, and the decoded data is supplied to the player controller 13. Note that the lead-in area of disc 2 indicates that the disc is an audio disc (C
D) or memory disk (CD-ROM), the subcode Q signal includes TOC
Index information called (Table Of Contelts) is recorded, and this TOC information is also decoded by the subcode decoder 10. Further, in this embodiment, it is assumed that map data, for example, is stored in the memory disk.

The player controller 13 is constituted by a microcomputer, and the drive control of the loading mechanism 3 and the slider drive circuit 14 are controlled by the processor.
The position of the pickup 6 in the disk radial direction is controlled by driving the slider motor 7 via the spindle drive circuit 15, and the drive of the spindle motor 5 is controlled via the spindle drive circuit 15. Based on the disc identification information in the TOC information obtained by decoding by the subcode decoder 10, it is also determined whether the disc being played is an audio disc or a memory disc.

The demodulated output of the EFM demodulation circuit 9 is sent to the CD-ROM decoder 1.
6 is also supplied. The CD-ROM decoder 16 decodes map data obtained by reading from a memory disk (CD-ROM) and demodulating it with the EFM demodulation circuit 9, and supplies it to the image display controller 20 via a path line BL made of, for example, an optical fiber. . The image display controller 20 performs control to display images such as maps on a display unit 19 such as a liquid crystal display based on display information signals such as map data supplied from the CD-ROM decoder 16.

Further, a mute circuit 21 is provided downstream of the EFM demodulation circuit 9 and is controlled by the player controller 13 to be turned off in the performance mode and turned on in other times. Output error correction circuit 11 and CD-ROM 1
By prohibiting the transmission to 6, the system is configured to prevent the generation of abnormal sounds due to noise etc. when playing an audio disk, and to prevent the generation of pseudo data due to noise etc. when playing a memory disk.

The system controller 17 is constituted by a microcomputer and controls the entire system. A player controller 13 and a CD-ROM decoder 16 are connected to the system controller 17 via a path line BL, respectively, so that information is exchanged with the controller 17. The pass line BL is further connected to an operation unit 18 that issues various commands such as designation of a map number and designation of an audio disc/mechanism disc by the user's keystrokes.

Next, the processing procedure executed by the processor of the player controller 13 when reading the map data of a desired map from the memory disk will be explained with reference to the flowchart of FIG.

In addition, in this routine, for example, when the user manually issues a reading command by keying a desired map number on the operation unit 18, the system controller 17 designates the start address of the map data corresponding to that map number as the target address. It is assumed that the command is called and executed when the read command is sent together with the read command.

Upon receiving a read command from the system controller 17, the processor first determines whether the current address based on the subcode address obtained from the subcode decoder 10 matches the target address (step S1).
, if the two addresses do not match, the number n of tracks to jump from the current address position to the target address position is determined from the difference between the two addresses (step S2). Next, the processor determines which of the two addresses is larger (step S3), and if the current address is larger, the optical spot of the pickup 6 is set to REV by n tracks.
If the target address is larger, the optical spot of the pickup 6 is controlled to jump in the FWD direction by n tracks (step S5), and then the process returns to step S1.

If it is determined in step S1 that the current address matches the target address, this means that the search for the target address has been completed. In step S6), it is determined whether the disc is an audio disc (CD) or a memory disc (CD-ROM). If it is a memory disc, the disc is moved by a predetermined distance in the address decreasing direction (REV direction) from the target address position, for example. The light spot of the pickup 6 is jumped by a predetermined number of tracks (5 tracks in this example) in the disk radial direction (step S7), and then the muting by the mute circuit 21 is canceled (step S8).
), then the mode shifts to the performance mode, and if it is an audio disc, the mode shifts directly to the performance mode via step S8.

In this way, when playing a memory disk, by starting the performance from a position with a sufficient margin in the address decreasing direction from the specified target address, even if there is a slight delay in the timing of unmuting, the delay can be covered. , data can be reliably output from the specified target address. As a result, if the data stored in the memory disk is map data, for example, the specified map data can be reliably read from the beginning of one map unit. In the case of an audio disc, the beginning of a song may be missing due to a delay in the timing of unmuting, but in the case of a musical tone, there is no discomfort even if the song is played from the middle.

In the above embodiment, the performance start position is set at a distance corresponding to the predetermined number of tracks in the disk radial direction in the address decreasing direction (REV direction) from the target address position. A position separated by a distance corresponding to a predetermined number of addresses in the axial direction may be set as the performance start position.

Furthermore, in the above embodiment, the performance start position is set after searching for the -degree target address, but the performance start position is set in advance based on the specified target address, and the set performance start position is directly searched. It is also possible to configure it to do so.

As described in detail of the invention, in the data reproduction processing device according to the present invention, when a target address for reading recorded data from a memory disk is specified, a position that is a predetermined distance away from the target address position in the address decreasing direction is used. is set as the reading start position, the reading start position is searched, and the performance is started from this position.
Even if the timing of unmuting is delayed, data at the specified target address can be reliably output.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing the processing procedure when reading data executed by the processor of the player controller, and FIG. 4(B) shows the format of the subcode Q signal, FIG. 4(A) shows the frame structure of CD-ROM data, and FIG. 4(B) shows the CD-ROM data format and header. It is a figure which shows each format. Explanation of symbols of main parts 1...Disc player 3...Loading mechanism 6...Pickup 9...EFM demodulation circuit 10...Sub Code decoder 13...Player controller 16...
・CD-ROM decoder 17...System controller 21...Mute circuit

Claims (3)

[Claims] (1) reading means for reading recorded information on a memory disk; demodulating means for demodulating the information read by the reading means;
a decoder for decoding data in the demodulated output of the demodulating means; a muting means for prohibiting the transmission of the demodulated output of the demodulating means to the decoder during the existence period of the control signal; A data reproducing processing device comprising means for generating a signal, means for specifying a target address at which recorded data is to be read from the memory disk, and a position distant from the target address position by a predetermined distance in an address decreasing direction. A data reproduction processing device comprising: means for setting a reading start position by the reading means; and means for controlling the reading means to move to the reading start position. (2) The data reproduction processing device according to claim 1, wherein the predetermined distance is a distance determined by a predetermined number of tracks in the radial direction of the disc. (3) The data reproduction processing device according to claim 1, wherein the predetermined distance is a distance determined by a predetermined number of addresses in a time axis direction.