JPH0421927A - Seek control circuit for optical disk drive device - Google Patents

Abstract

PURPOSE:To stabilize and accelerate the detection of a boundary address by detecting the boundary address between a recorded area, where a phase bit or a recording bit is formed, and an unrecorded area, where the various bits are not formed, according to the difference of the signal amplitudes of reproduc ing signals. CONSTITUTION:An optical pickup part is moved to the objective boundary address position and after the movement, the address No. is read. Difference 'S' between the current address value and the boundary address value is calculated and only for the 'S', the optical pickup is moved. During this movement, a boundary address detection circuit 6 is operated to monitor a change in the L level of a boundary part detection signal C after passing an F/S converter 9. Thus, the boundar address between a recorded area 4, where the phase bit or the recording bit is formed, and an unrecorded area 5 is securely detected at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a seek control circuit for an optical disk drive device.

2. Description of the Related Art Conventionally, in an optical disk drive device, the principle of seeking movement of an optical pickup unit having an objective lens, etc., which is arranged to face an optical disk as an optical information recording medium is described in the fifth principle.
This will be explained based on the diagram and FIG.

In the flow shown in FIG. 5, first, the current radial position of the optical disk is calculated from the target address, and the optical pickup section is moved by the coarse movement motor. At this time, the output from the linear scale is used to detect the radial position of the optical disc. After the rough movement, tracking is performed and address information is read.

The difference "S" between this read address and the target address is calculated. If the value of S is not O, the optical pickup section is driven by the amount of S by the actuator to slightly move it. In this case, since there is no resolution in detecting the radial position from the linear scale, a "cross track signal" is used as a method for detecting the moving distance. This cross-track signal includes an RF multiplied signal reproduction signal) and a TE signal.
(track error signal) is used.

FIG. 6 shows the waveform of the cross-track signal. That is, when a light beam is scanned in the direction of the arrow over a pit 3 formed on a track center 2 between groups 1 on an optical disk, an RF multiplied signal and a TE multiplied signal as a cross track signal are generated as a solid line. The waveform will be as shown.

In this way, no matter which signal is used, the RF multiplied signal or the TE multiplied signal, one pulse output is obtained every time one track is crossed. Therefore, by counting these pulses, it is possible to detect how many tracks have been moved.

Thereafter, while monitoring the cross-track signal, the optical pickup section is finely adjusted and tracking is performed again to read the address information. And if the value of S is not O,
This operation is repeated again, and the seek operation is performed until the target address is reached.

Problems to be Solved by the Invention In the case of the above-described method of counting the number of traversed tracks using a lost track signal, the stability of the cross track signal is important. In FIG. 6, when there are pits 3 such as phase pits or recording pits, the RF multiplied signal and the TE multiplied signal have waveforms shown by dotted lines. In this case, the waveform of the cross-track signal will be disturbed, and there is a possibility that the number of tracks will be detected incorrectly when counted. In particular, in standardized type optical discs, system information called rsFPJ is formed as a group of phase pits in the preformat part, so when seeking these SFPs,
The waveform of the cross-track signal (RF multiplied signal and TE multiplied signal) is in a disturbed state. Such waveform disturbance also occurs in an area where recording pits are formed as a group in the data section.

That is, as shown in FIG. 7, there is a recorded area 4 in which pits 3 (phase pits or recording pits) are formed as a cluster between group 1, and an unrecorded area only in group 1 where pits 3 are not formed. When the light beam is scanned along the direction of the arrow on the surface of the optical disk where 5 exists, R
The waveform of the F-fold signal, TE-fold signal, and cross-track signal is distorted when it passes through the recorded area 4, resulting in a reading error in counting the number of tracks. This allows the pit (S
The same problem occurs when it takes time to seek over the recorded area 4 formed by a crowd of FPs, etc., or when detecting the boundary between the recorded area 4 and the unrecorded area 5. problems occur.

Means for Solving the Problem Therefore, in order to solve such problems, claim 1
The described invention includes an optical information recording medium having phase pits formed as preformat signals and recording pits formed as data signals, and reproduces information reproduction signals and track error signals by light reflected from the optical information recording medium. In an optical disk drive device that detects a focus error signal, the boundary address between the recorded area where the phase pits and the recording pits are formed and the unrecorded area where these various pits are not formed is determined by the signal amplitude of the playback signal. Boundary address detection means is provided to detect the difference between the two boundaries.

The invention according to claim 2 is provided with an optical information recording medium having phase pits formed as preformat signals and recording pits formed as data signals, and reproduces an information reproduction signal or the like by the reflected light from the optical information recording medium. In an optical disk drive device that detects a track error signal and a focus error signal, the boundary address between the recorded area where the phase pits and the recording pits are formed and the unrecorded area where these various pits are not formed is the track error signal. Boundary address detection means for detecting a difference in signal amplitude of signals is provided.

According to the invention described in claim 1, the boundary address detection means is used to detect the boundary address between the recorded area in which phase pits and recorded pits are formed and the unrecorded area in which these various pits are not formed, by determining the signal amplitude of the reproduced signal. By detecting the difference between the two, it is possible to stably and quickly detect the boundary address.

According to the invention as set forth in claim 2, the boundary address between the recorded area in which phase pits and recording pits are formed and the unrecorded area in which these various pits are not formed is determined by the signal amplitude of the track error signal using the boundary address detection means. By detecting the difference between the two, it is possible to stably and quickly detect the boundary address.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. Note that the same reference numerals are used for the same parts as in the prior art (see FIG. 7), and the explanation thereof will be omitted.

FIG. 1 shows the configuration of a boundary address detection circuit 6 as a boundary address detection means. This boundary address detection circuit 6 is composed of an AC coupling 7, a comparator 8, and an F-V converter 9. The boundary address detection circuit 6 configured as described above detects the boundary address between the recorded area 4 where pits 3 such as phase pits and recording pits are formed and the unrecorded area 5 where these pits 3 are not formed. Detection is performed based on the difference in signal amplitude of reproduced signals (hereinafter referred to as RF multiplied signals). Therefore, in this embodiment, hereinafter, a type of RF multiplied signal cross-track signal)
Using this, the boundary address detection circuit 6 detects the boundary address (part of group 1) between the recorded area 4 where pits 3 are formed as a group and the unrecorded area 5 of only group 1 where pits 3 are not formed. This section describes a method for detecting (equivalent to).

First, the RF multiplied signal detected by the optical disk drive device is input to the AC coupling 7, and thereby DC level fluctuations are removed (DC level fluctuations are caused by variations in the reflectance of the recording film and warping of the substrate. ). Next, the coupling signal a obtained by the AC coupling 7 is sent to a comparator 8 and converted into a binary signal. The threshold level for this binarization needs to be set to such an extent that the RF multiplied signal of the recorded area 4 is not binarized, as shown in FIG. Next, the binary signal is F-
By sending the signal to the V converter 9, a boundary detection signal C whose level changes at the boundary between the recorded area 4 and the unrecorded area 5 is obtained.

A method for detecting a "boundary address" based on the boundary detection signal C detected in this way will be explained based on the flowchart of FIG. 3. First, the optical pickup unit is moved to the target boundary address position, and the address number after the movement is read. The difference "S" between the read current address value and the boundary address value is calculated, and the optical pickup section is moved by the amount S. Also, during this move,
The boundary address detection circuit 6 is in operation, and changes in the L level of the boundary detection signal C after passing through the F-V converter 9 are monitored. If there is a change in the L level of this boundary detection signal C, the seek movement is stopped and tracking is applied, thereby completing the seek operation. If there is a time lag between the L level of the boundary detection signal C and tracking pull-in, the controller jumps back several tracks after tracking pull-in and waits until the target address is reached.

Therefore, in the conventional boundary address detection method, pit 3
cross-track signal (there are fluctuations in the RF multiplied signal,
As a result, in order to access the target address in a state where an error has occurred in the count, it was necessary to repeat the operation of I → Tsu → Work → O several times in FIG. By detecting the boundary detection signal C using the boundary address detection circuit 6,
Since it has become possible to complete the seek operation by performing the force → key operation only once, this allows the recorded area 4 in which phase pits or recording pits have been formed.
Detection of the boundary address between the recording area and the unrecorded area 5 can be performed reliably and at high speed.

Next, a second embodiment of the present invention will be described based on FIG. 4. In the embodiment described above, R is used as a cross-track signal.
Although the F-fold signal was used, here, the TE-fold signal (track error signal) is used as the cross-track signal. Further, in accordance with this, the boundary address detection circuit 10 as a boundary address detection means has a circuit configuration as shown in FIG. That is, the boundary address detection circuit 1o is
It is composed of a comparator 8 and an F-V converter 9. As a result, the boundary detection signal C can be obtained by inputting the TE multiplied signal detected by the optical disk drive device to the comparator 8 to obtain a binary signal, and then sending it to the F-V converter 9. By executing the flow shown in Fig. 3 based on the above, the boundary address between the recorded area 4 where pits 3 are formed as a group and the unrecorded area 5 of only group 1 where pits 3 are not formed can be found. can be detected. Therefore, this makes it possible to detect the boundary address between the recorded area 4 in which phase pits or recorded pits are formed and the unrecorded area 5 reliably and at high speed.

Effects of the Invention The invention according to claim 1 comprises an optical information recording medium having phase pits formed as a preformat signal and recording pits formed as a data signal, and information is recorded by reflected light from the second optical information recording medium. In an optical disk drive device that detects playback signals, track error signals, and focus error signals, the boundary address between the recorded area where phase pits and recording pits are formed and the unrecorded area where these various pits are not formed is reproduced. Since we have provided a boundary address detection means that detects based on the difference in the signal amplitude of the signals,
By using the boundary address detection means to detect the boundary address between the recorded area and the unrecorded area based on the difference in signal amplitude of the reproduced signal, it is possible to detect the boundary address more stably and at a higher speed than in the past. It is possible.

The invention according to claim 2 includes an optical information recording medium having phase pits formed as preformat signals and recording pits formed as data signals, and reproduces an information reproduction signal or the like by reflected light from the optical information recording medium. In an optical disk drive device that detects a track error signal and a focus error signal, the boundary address between a recorded area where phase pits and recording pits are formed and an unrecorded area where these various pits are not formed is determined by the track error signal. Since a boundary address detection means is provided which detects by the difference in signal amplitude, by using the boundary address detection means to detect the boundary address between the recorded area and the unrecorded area by the difference in the signal amplitude of the track error signal, This makes it possible to detect boundary addresses more stably and faster than in the past.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the boundary address detection means according to the first embodiment of the present invention, FIG. 2 is a waveform diagram showing the boundary detection method, and FIG. 3 shows the principle of boundary address detection. Flowchart, FIG. 4 is a block diagram showing the configuration of the boundary address detection means according to the second embodiment of the present invention, FIG. 5 is a flowchart showing the principle of detecting boundary addresses by the conventional method, and FIG. Figure 7 shows the waveform diagram of the cross-track signal when scanning between a recorded area and an unrecorded area where pits are clustered. FIG. 3...Pit, 4...Recorded area, 5...Unrecorded area, 6.10...For boundary address detection means Applicant: Ricox Co., Ltd. TE RF Yugo ND

Claims (1)

[Claims] 1. An optical information recording medium having phase pits formed as preformat signals and recording pits formed as data signals is provided, and information reproduction signals and information are generated by reflected light from the optical information recording medium. In an optical disk drive device that detects a track error signal and a focus error signal, the boundary address between the recorded area where the phase pits and the recording pits are formed and the unrecorded area where these various pits are not formed is determined by the playback signal. 1. A seek control circuit for an optical disk drive device, characterized in that a boundary address detection means is provided for detecting a boundary address based on a difference in signal amplitude. 2. Equipped with an optical information recording medium that has phase pits formed as preformat signals and recording pits formed as data signals, and uses reflected light from this optical information recording medium to generate information reproduction signals, track error signals, and focus errors. In an optical disk drive device that detects signals, the boundary address between the recorded area where the phase pits and recording pits are formed and the unrecorded area where these various pits are not formed is determined by the difference in signal amplitude of the track error signal. 1. A seek control circuit for an optical disc drive device, characterized in that a boundary address detection means for detecting a boundary address is provided.