JPH05342819A - Information reproducing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To detect the position of the information reproducing head in an optical disc having MCAV format and reproducing data in sector units. When the disk change detection means 8 detects that the optical disk 2 is inserted or the information reproducing apparatus 1 is powered on, the microcontroller 9 fixes the information reproducing head 3 to the head moving means 4. To move to another zone, and at the same time, to instruct the clock generation means 7 to generate a clock corresponding to this zone. As a result, the clock of the zone where the information reproducing head 3 is present is supplied to the address reproducing means 5, the address is reproduced correctly, and the position where the information reproducing head 3 exists is determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reproducing apparatus which uses a disc-shaped information recording medium and reproduces information in units of sectors formed on the information recording medium.

[0002]

2. Description of the Related Art In a disk-shaped information recording medium having a large number of concentric or spiral tracks, these tracks are divided into a plurality of zones in the radial direction of the disk, and the same number of tracks are provided in each zone. When a sector format is formed and the number of sectors formed in the track increases from the inner circumference to the outer circumference zone, the MCAV (Mo
dified Constant Angular Velocity) format. This MCAV format information recording medium is used under an information reproducing apparatus whose rotation speed is constant.

FIG. 3 is a schematic view of an information recording medium having a conventional MCAV format.

In the information recording medium, a data recording area in which user data can be recorded is divided into a plurality of zones,
In FIG. 3, only two adjacent zones are shown. Each track in zone (i) is divided into n sectors, while each track in zone (i + 1) is divided into (n-1) sectors. FIG. 4 shows a zone (i) and a zone (i) in a disc having such an MCAV format.
FIG. 3 is a schematic diagram of a reproduction signal on an arbitrary track of (+1). In FIG. 4, track (j) is divided into n sectors, while track (j + 1) is divided into (n-1) sectors. Each sector has a fixed size and is composed of an ID section in which address information is recorded and a DF section in which user data is recorded.

Here, reproduction of data on such an information recording medium is performed as follows. In order to reproduce the data on the sector, first, the ID portion of the sector where the information reproducing head is currently located is read. Next, it is confirmed whether or not the read address of the ID part is of the target sector. Here, if it is confirmed that the address is in the target sector, the reproduction of data from the DF section is performed. If the address is different from that of the target sector, the information reproducing head is moved to perform a so-called seek operation, and the sector ID portion is read again at the movement destination to confirm the address and the data from the DF portion is read. Playback is performed. In order to reproduce such an ID part, a clock corresponding to the recording density on the time axis of the sector to be reproduced is required.

However, in the MCAV format information recording medium, since the recording density on the time axis is different for each zone, the clock for reproducing the ID portion is different for each zone and is not constant. For this reason, in reproducing the ID portion of a conventional MCAV format disc, when it is not possible to determine which zone the information reproducing head is present immediately after the disc is inserted, the reproduction clock is sequentially corresponded to each zone until the ID portion can be read. It was changing.

[0007]

However, in the system in which the reproduction clock is changed in a brute force manner for each zone in this way, in order to judge the position of the information reproduction head, in the worst case, all zones are It is necessary to generate a clock corresponding to. Therefore, particularly in a system in which the disc is frequently replaced, an overhead time is required to determine the position of the information reproducing head each time the disc is replaced, resulting in poor efficiency.

In view of the above points, the present invention has an object to provide an information reproducing apparatus capable of quickly determining the accurate position of the information reproducing head.

[0009]

The information reproducing apparatus of the present invention uses a disc-shaped information recording medium having an MCAV format, and moves the information reproducing head for detecting a signal from the information recording medium and the information reproducing head. Head moving means, address reproducing means for extracting an address signal from a reproduced signal of a sector formed on an information recording medium, clock generating means for generating a clock required for address reproduction, and an MCAV format information recording medium are fixed. A controller for controlling the head moving means for moving the information reproducing head to a different zone, and controlling the clock generating means for generating a clock corresponding to this zone, and a disk change detecting means for detecting a change in the information recording medium. It is characterized by having and.

[0010]

According to the present invention, when the disk change detecting means detects that the disk is inserted or the power of the apparatus is turned on, the controller fixes the information reproducing head to the head moving means. To move to the designated zone, and at the same time, to instruct the clock generating means to generate the clock corresponding to this zone. As a result, the clock of the zone in which the information reproducing head exists is supplied to the address reproducing means, the address is reproduced correctly, and the accurate position where the information reproducing head exists is quickly determined.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An information reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the information reproducing apparatus of the present invention. In FIG. 1, reference numeral 1 is an information reproducing apparatus according to an embodiment of the present invention, 2 is an optical disk which is an information recording medium using the MCAV format, and 3 is a laser beam focused on a track of the optical disk 2 to detect a reproduction signal. The information reproducing head 4, a head moving means for moving the information reproducing head 3 to a predetermined track, 5 discriminates and demodulates the address signal included in the reproduced signal and detected from the ID portion of each sector of the optical disk 2. Address reproducing means for generating address information, 6 is a data reproducing means for discriminating and demodulating a data signal recorded in the DF portion from a reproduced signal to generate demodulated data, and 7 is a frequency reproduction corresponding to each zone of the optical disc 2. Clock generating means for generating a clock, 8
Is a disc change detecting means for detecting that the optical disc 2 is newly inserted or the power of the information reproducing device 1 is turned on, and 9 controls the entire information reproducing device 1 according to a control program stored therein. A microcontroller 9a is built in the microcontroller 9 and a clock initialization means for instructing the clock generating means 7 to generate a reproduction clock corresponding to the outermost zone of the optical disc 2 is provided 9b in the microcontroller 9. , Head position initialization means for instructing the head moving means 4 to move the information reproducing head 3 to the outermost zone of the optical disc 2.

FIG. 2 is an area diagram on the optical disc 2 in the position embodiment of the present invention. The optical disc 2 using the MCAV format is divided into n zones from zone 1 to zone n. A dummy track area 1 is provided on the outer peripheral side of zone 1 which is the outermost peripheral zone, and a dummy track area 2 is provided on the inner peripheral side of zone n which is the innermost peripheral zone.
Are formed. These dummy tracks are arranged for the purpose of preventing the information reproducing head 3 from moving to an area where no track exists. In other words, the head movement range, which is the movement range of the information reproducing head 3 that is physically determined, is such that one of the tracks of the dummy track area 1 is the outermost circumference side and one of the dummy track area 2 is the innermost circumference side. To do. In the optical disc 2, the data area in which the data to be reproduced is recorded is the remaining area excluding the dummy track area 1 and the dummy track area 2 from the area of each zone.

The operation of deciding the position of the information reproducing head 2 and reproducing the data from the optical disk 2 in the information reproducing apparatus having the above-mentioned structure will be described.

First, it is assumed that the optical disc 2 is inserted into the information reproducing apparatus 1. A motor (not shown) of the information reproducing apparatus 1 starts the rotation of the optical disc 2. The disc change detection means 8 detects the insertion of the optical disc 2 and reports this to the microcontroller 9. The microcontroller 9 receives this report and performs the following operation. The clock initialization means 9a in the microcontroller 9 instructs the clock generation means 7 to generate a reproduction clock corresponding to zone 1, which is the outermost zone of the optical disc 2.
The clock generation means 7 starts generation of a reproduction clock having a frequency corresponding to zone 1. Further, the head position initializing means 9b in the microcontroller 9 instructs the head moving means 4 to move the information reproducing head 3 to the outermost peripheral side of the head moving range. The head moving means 4 moves the information reproducing head 3 to the outermost side of the head moving range of the optical disc 2.

When the rotation of the optical disk 2 reaches the specified speed, the microcontroller 9 activates the address reproducing means 5. At this time, the information reproducing head 3 is already located on the outermost side of the head moving range, that is, in the dummy track area 1 in the zone 1. Therefore, the reproduction clock supplied from the clock generation means 7 to the address reproduction means 5 is
It matches the clock of the reproduction signal detected by the information reproducing head 3. In this way, since the reproduction clock necessary for address reproduction is correctly supplied, the address reproduction means 5 can reproduce the address of the sector in which the information reproduction head 3 is located. The microcontroller 9
The sector on which the information reproducing head 3 is located is known from the address reproduced by the address reproducing means 5.

After that, when an external system (not shown) sends a data read command to the microcontroller 9, the microcontroller 9 reads the data with reference to the current position of the information reproducing head 3. Perform a seek operation to the track including the sector to be performed. After the seek operation is completed, the data reproducing means 6 reproduces the data in the target sector and sends it as reproduced data to the external system.

As described above, when the optical disk 2 is newly inserted into the information reproducing apparatus 1, the disk change detecting means 8 detects this, and in response to this, the microcontroller 9 makes the clock generating means 7 the outermost periphery. Of the reproduction clock corresponding to the zone of the
The information reproducing head 3 is instructed to move to the dummy track area 1 located on the outermost periphery of the optical disc 2. As described above, since the reproduction clock corresponding to the position of the information reproducing head 3 is supplied to the address reproducing means 5, the address reproduction is correctly performed, and the subsequent data read operation is performed.

Further, even when the electrode is newly inserted in the information reproducing apparatus 1, the disc change detecting means 8 detects this and reports it to the microcontroller 9, whereby the above-mentioned optical disc 2 is newly inserted. The same operation is performed as in the case of the above. In this case as well, the address of the sector in which the information reproducing head 3 is located is correctly reproduced by the same procedure as when the optical disk 2 is inserted.

In this embodiment, when the disc change detection means 8 detects the insertion of the optical disc 2, the clock initialization means 9a instructs the clock generation means 7 to generate a reproduction clock corresponding to the outermost zone. Then, the head position initialization means 9b instructs the head movement means 4 to move to the dummy track area 1 located in the outermost zone, but the clock initialization means 9a instructs the clock generation means 7 to do so. On the other hand, the generation of the reproduction clock corresponding to the innermost zone is instructed, and the head position initialization means 9b instructs the head moving means 4 to move to the dummy track area 2 located in the innermost zone. If you do
Obviously, the invention can be applied as well.

[0021]

As described above, according to the present invention, the controller instructs the head moving means to move the information reproducing head to the fixed zone, and at the same time, the clock generating means receives the clock corresponding to this zone. By instructing to generate, the clock of the zone in which the information reproducing head is present is supplied to the address reproducing means, and the address is reproduced correctly.

Therefore, according to the present invention, it is possible to quickly determine the exact position of the information reproducing head without changing the reproducing clock for each zone in a brute force manner, and confirm the address when the optical disk is inserted. Overhead time can be minimized.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an information reproducing apparatus of the present invention.

[Figure 2] Area diagram on optical disk

FIG. 3 is a schematic diagram of an information recording medium having an MCAV format.

FIG. 4 is a schematic diagram of a reproduced signal.

[Explanation of symbols]

 1 information reproducing apparatus 2 optical disk 3 information reproducing head 4 head moving means 5 address reproducing means 6 data reproducing means 7 clock generating means 8 disk change detecting means 9 micro controller 9a clock initializing means 9b head position initializing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Takagi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Yuji Hisakado 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A disc-shaped information recording medium having an MCAV format is used, an information reproducing head for detecting a signal from the information recording medium, a head moving means for moving the information reproducing head, and the information recording medium. Address reproducing means for performing address reproduction from the reproduced signal of the formed sector, clock generating means for generating a clock necessary for the address reproduction, and the information reproducing head for moving to a fixed zone of the information recording medium. Information reproduction including a microcontroller for controlling the head moving means and controlling the clock generating means so as to generate a clock corresponding to the zone, and a disk change detecting means for detecting a change in the information recording medium. apparatus. 2. The information reproducing apparatus according to claim 1, wherein the information recording medium is changed by inserting the information recording medium and turning on the power of the information reproducing apparatus. 3. A disc-shaped information recording medium having the MCAV format is used, an information reproducing head for detecting a signal from the information recording medium, a head moving means for moving the information reproducing head, and the information recording medium. Address reproducing means for performing address reproduction from the reproduced signal of the formed sector, clock generating means for generating a clock necessary for the address reproduction, and the information reproducing head for moving to a fixed zone of the information recording medium. Head position initialization means for controlling the head moving means, clock initialization means for controlling the clock generation means so as to generate a clock corresponding to the zone, and disk change for detecting a change of the information recording medium. An information reproducing apparatus having a detecting means. 4. The information reproducing apparatus according to claim 3, wherein the information recording medium is changed by inserting the information recording medium and turning on the power of the information reproducing apparatus.