JPH03266269A - Information recording/reproducing device - Google Patents

Abstract

PURPOSE:To remove the dead time of setting time at the time of the start of a tracking servo system by setting the setting time beforehand correspondingly to the amount of the movement of a pickup. CONSTITUTION:A CPU 4 selects the setting time corresponding to the number of tracks over which the pickup moves from the list of the setting time stored in a ROM 9, and sets it in an inner count. Accordingly, in an address search executing system, operation is shifted to servo control in the setting time selected from the list of the setting time determined beforehand according to address information from a recording medium and the amount of the movement of the pickup to a designated address. Thus, when the amount of the movement of the pickup 3 is large, time required for setting is taken sufficiently, but when the amount of the movement of the pickup 3 is small, the setting time is made short, and address search without the dead time to meet the actual control of the tracking servo system can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an information recording/reproducing apparatus for optically or magneto-optically recording and reproducing information on a recording medium such as an optical disk.

(Prior Art) In this type of information recording and reproducing apparatus, address information on a recording medium is read by an address search execution system, and a pickup is moved to a designated target address without operating a tracking servo. At this time, the address search execution system counts the number of tracks crossed by the pickup based on the track error signal generated when the search beam irradiated from the laser diode crosses the tracks formed on the recording medium, and the count value is determined as the target address. When it becomes equal to the relative number of tracks up to,
Switching to tracking servo. However, at this point, the tracking servo system is not stable, and the settling time until the servo system becomes stable is set in advance as an interval t. After this settling time,
Assuming that the tracking servo system is stable, the track address reached by the current pickup is confirmed and the address search is completed. The above-mentioned required settling time varies depending on each information recording/reproducing master device and also varies due to changes over time, so the current situation is that it is set long in advance in anticipation of this. .

(Problem to be Solved by the Invention) For this reason, when moving the pickup within an extremely short range, the settling time occupies a non-negligible amount of time compared to the time required for the pickup to actually access the target address. It will be a long one. (In recent years, the performance of sliders and actuators has improved, and the time required to actually access the target address of the pickup even when moving the pickup over a relatively long range has been shortened.) In setting the above-mentioned settling time, it is important to avoid wasted time.

(Object of the Invention) The present invention has been made based on the above circumstances, and focuses on the fact that in a tracking servo system, there is a difference in the time required for the servo system to stabilize depending on the amount of pickup movement. It is an object of the present invention to provide an information recording and reproducing device that eliminates wasted time when setting a settling time.

(Means for Solving the Problem) Therefore, in the present invention, the address information in the recording medium is read by the address search execution system, the pickup is moved to the specified address, and the address search execution system is stabilized. In an optical or magneto-optical information recording/reproducing device that waits a certain amount of time before starting a recording or reproducing operation, the address search execution system uses the address information read from the recording medium and the amount of pickup movement to the specified address. Accordingly, the system is configured to shift to servo control at a settling time selected from a list of predetermined settling times.

(Function) For this reason, when the amount of movement of the pickup is large, sufficient time is required for settling, but when the amount of movement of the pickup is small, the settling time is shortened to avoid unnecessary waste that suits the actual control of the tracking servo system. It is possible to perform address searches in no time.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to the drawings. In FIG. 3, reference numeral 1 includes address information.
It is a recording medium such as a magneto-optical disk, and is rotationally driven by a spindle motor 2.

On the other hand, the pickup 3 whose movement is controlled across the track of the recording medium 1 includes, for example, a laser diode 13 as a light source for irradiating light onto the recording medium 1,
The light beam from this light source is made into a parallel light beam by a collimator lens 16, guided to an objective lens 15 via a half prism 17, and condensed onto the recording medium.
A light receiving sensor 14 such as a 4-split sensor captures the reflected light from the 4-split sensor, converts it into an electrical signal, and supplies the electrical signal to the information reproducing circuit 5. The pickup 3 above is ROM
The pickup drive system 10 is operated by a pickup movement signal from the CPU 4, which includes a RAM, an I10 board, an AD converter, and a zero-cross detector.
A seek operation that moves in the radial direction of the recording medium can be performed. The track address, which is a control information source for seek, is included in the signal sent from the information reproducing circuit 5 to the track address detection circuit 8, and is discriminated from the track address detection circuit 8 as a signal e and given to the CPU 4. . The control signal a for the tracking servo is sent to the CPU4.
The resulting feedback signal is provided to the tracking control circuit 6 and CPtJ4 in the form of signal C from the information reproducing circuit 5. Information for focus control of the pickup 3 on the track is given to the focus control circuit 7 via the information reproducing circuit 5. In addition, in the figure, the code 11 is
A recording operation control circuit 12 digitizes recording information from the outside, and a recording operation control circuit 12 uses this output to digitize the above-mentioned laser diode 1.
This is a laser control circuit that provides a pulse signal to 3. In particular, in the present invention, data listing settling times corresponding to the amount of movement of the pickup to the target address is prerecorded in the ROM 9 connected to the CPU 4.

Next, a detailed explanation will be given with reference to FIGS. 1, 2, and 4. Based on the flowchart of FIG. 4, in step S1, the CPU 4 is waiting for an address search command from the host system. When an address search command is received, the process advances to the next step S2. Here, the CPU 4 converts the reflected light of the laser beam irradiated onto the recording medium into 4
The address detection circuit 8 obtains the discriminated track address where the pickup 3 is currently located from the electrical signals obtained through the divided sensor and the information reproducing circuit.

Next, the process moves to step S3, where the number of tracks the pickup 3 moves is calculated from the track address detected in step S2 and the target track address given in step Sl. Next, in step S4, CP
U4 stores the settling time corresponding to the number of moving tracks given in step S3 in the ROM 9, selects it from a list of settling times, and sets it in the internal count. The settling time at this time corresponds to the amount of pickup movement; for example, for long-distance movement, it is t long in FIG. 2, and for short-distance movement, it is t 5hort.

Next, in step S5, the CPtJ4 controls the tracking control circuit 6 to turn off the tracking servo using the signal a, so that the pickup 3 can be driven by the pickup drive system IO (see step S6). For this purpose, the CPU 4 outputs a signal. When the pickup 3 starts moving, the tracking error signal (signal C) changes every time the pickup 3 crosses a track on the recording medium 1, as shown in FIG. In step S7, the CPU 4 increments the internal track number counter by one each time it detects that the tracking error signal crosses the zero level. Although the zero level detector is not shown in FIG. 3, it is included in the CPU 4. In step S8, it is determined whether the counter has become equal to the number of tracks calculated in step S3. If they are equal, the process proceeds to the next step S9; if not, the process returns to step S8 and continues counting. When the CPU 4 detects that the pickup has crossed the target number of tracks, in step S9, the CPU 4 again issues a command to turn on the tracking servo to the tracking control circuit at that point, and also turns off the signal to stop the pickup movement. , the pickup 3 is fixed to the truck. Steps SI0, 11 and 12
Then, the tracking servo system waits for stabilization. That is, the CPU 4 monitors the settling signal d, and if it continues to be at a high level for the settling time set in step S4 after detecting the rising edge of the signal d (point A), the settling is completed. . The settling signal d is generated by the tracking control circuit 6, and is similar to the signal C in FIG.
is V1. When it is outside the V g level, it becomes Low and V l again.

■Return to High when entering the level. If the settling fails, that is, if the high level cannot be maintained, the settling time is set again in the counter in the CPU 4 (see step S15), and the process returns to step SIO. Once settling is complete, in step SL3.14, CPU 4 reads the media track address where the pickup is located and checks whether it is the target address. If it matches the target address, the instruction in this routine is completed and the process returns to the main routine; however, if it does not match, the process returns to step S2 to perform the address search again.

In the above embodiment, if the ROM in which the CPLI 4 stores firmware has sufficient capacity, it is also possible to store the contents of the settling time list in the ROM of the CPU 4.

(Effects of the Invention) The present invention has been described in detail above, and the settling time is set in advance in accordance with the amount of movement of the pickup, thereby eliminating wasted settling time when entering the tracking servo system. This makes it possible to speed up address searches.

[Brief explanation of drawings]

FIGS. 1 and 2 show an embodiment of the present invention; FIG. 3 is a time chart showing the movement timing of the pickup; FIG. 3 is a block diagram of the embodiment; and FIG. 4 is a flowchart for controlling the operation. It is. DESCRIPTION OF SYMBOLS 1... Recording medium, 2... Spindle, 3... Pickup, 4... CPU, 5... Information reproducing circuit, 6
... Tracking control circuit, 7... Focus control circuit, 8... Track address detection circuit, 9...
ROM, 10...Pickup drive system, 13...Laser diode, 4...4-split sensor.

Claims (1)

[Claims] An optical system that reads the address information on the recording medium using an address search execution system, moves the pickup to the specified address, waits for a settling time for the address search execution system to stabilize, and then starts recording or playback operation. Alternatively, in a magneto-optical information recording/reproducing device, the address search execution system performs a settling time selected from a list of predetermined settling times according to the address information read from the recording medium and the amount of pickup movement to the specified address. An information recording and reproducing device characterized in that it is configured to shift to servo control.