JPH04301276A - Data recorder and reproducer - Google Patents

Abstract

PURPOSE:To shorten access time by controlling head position decision in accordance with accuracy required by respective modes. CONSTITUTION:On-cylinder condition is set at every mode such as a seek mode, a data recording mode and a data reproducing mode and given to a head position decision control circuit 16 together with a target cylinder so that a head 13 is position-decided to the target cylinder in accordance with the on-cylinder condition.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording and reproducing apparatus such as a magnetic disk drive, and more particularly to a data recording and reproducing apparatus that controls head positioning by changing on-cylinder conditions.

0002

2. Description of the Related Art A recording medium used, for example, in a magnetic disk drive is provided with guard zones 1 on both sides of each track, as shown in FIG. Here, as shown in FIG. 6A, when recording data, it is necessary to accurately record on the previous data, so it is desirable that the head 2 be positioned at the center of the track. On the other hand, as shown in FIG. 6(b), when reproducing data, the position of the head 2 may be slightly shifted from the center of the track.

[0003] As described above, the precision required for head positioning control differs between the data recording mode and the data reproduction mode. However, conventionally, the same control was performed in the data recording mode and the data reproduction mode. That is,
Regardless of each mode of data recording, reproduction, etc., on-cylinder (on-track) status is always determined under the same conditions and the head is positioned on the target cylinder.

0004

As described above, in the conventional head positioning control, unnecessary precision is required during the data reproduction mode, which causes problems such as wasting time.

The present invention has been made in view of the above points, and provides a data recording and reproducing apparatus that performs head positioning control according to the accuracy required for each mode, thereby reducing access time. The purpose is to provide

[0006]

[Means for Solving the Problems] The present invention provides a data recording and reproducing apparatus that records or reproduces data by causing a head to seek to a target cylinder, and which performs at least a seek in a data recording mode and a seek in a data reproducing mode. Then, on-cylinder conditions for determining the completion of the seek are set, and the head is positioned at the target cylinder according to the set on-cylinder conditions.

[0007]

[Operation] According to the above structure, the on-cylinder conditions are changed for each mode, and the seek operation is performed according to the conditions. Therefore, head positioning control can be performed according to the precision required in each mode.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A data recording and 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 showing the configuration of a sector servo type magnetic disk device. In FIG. 1, 11
is a recording medium. Servo data 12 necessary for head positioning control is recorded on this recording medium 11 for each sector. The head 13 moves in the radial direction of the recording medium 11 and records/reproduces data.

The host device 14 sends various commands such as a seek command, a read command, and a write command to the controller 15. The controller 15 controls the entire magnetic disk device, such as head positioning control and data recording/reproduction control. Here, the on-cylinder conditions for determining the completion of a seek as well as the target cylinder are controlled by head positioning. Output to circuit 16. The head positioning control circuit 16 drives the VCM driver 17 under the control of the controller 15 to position the head 13 to the target cylinder. The VCM driver 17 includes a voice coil motor (not shown) that serves as a drive source for the head 13.
CM). The data recording/reproducing circuit 18 records/reproduces data under the control of the controller 15. The servo data detection circuit 19 is the data recording/reproducing circuit 1
Servo data 12 is detected from the reproduced data obtained from 8, a head position signal is generated based on this servo data 12, and this is output to a head positioning control circuit 16.

FIG. 3 is a diagram for explaining the on-cylinder conditions of the same embodiment. In FIG. 3, O1 indicates the on-cylinder range in the seek mode, O2 indicates the on-cylinder range in the data reproduction mode, and O3 indicates the on-cylinder range in the data recording mode. Further, T1 indicates the on-cylinder time in the seek mode, T2 indicates the on-cylinder time in the data reproduction mode, and T3 indicates the on-cylinder time in the data recording mode. In this embodiment, in the seek mode, it is sufficient to bring the head within the O1 range. This O1 range corresponds to one cylinder. If the head stays within the O1 range during t1, the seek is considered complete. Similarly, in data playback mode, T2
During T3, it is considered that the seek is completed if it is in the O2 range, and in the data recording mode, if it is in the O3 range during T3.

In comparison to FIG. 3, FIG. 4 shows conventional on-cylinder conditions. In FIG. 4, O4 indicates the on-cylinder range common to each mode. Further, t1 indicates the on-cylinder time in the seek mode, t2 indicates the on-cylinder time in the data reproduction mode, and t3 indicates the on-cylinder time in the data recording mode. Conventionally, the head must always be brought into the O4 range regardless of each mode. This O4 range corresponds to the O3 range in FIG. Then, if it is in seek mode, the head is t
If the seek is within the O4 range for 1, it is considered that the seek is complete. Similarly, the seek is considered complete if the seek is within the O4 range during t2 in the data reproducing mode and during t3 in the data recording mode. Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG.

[0013] In seek mode (step S1)
, the controller 15 sets the on-cylinder range to O1 and the on-cylinder time to T1 (step S2). Then, the controller 15 performs the O
1 and T1 are output to the head positioning control circuit 16 together with the target cylinder as on-cylinder conditions (step S3). The head positioning control circuit 16 controls the VCM driver 1 according to the on-cylinder conditions (O1, T1).
7 to seek the head 13 to the target cylinder (step S4).

Here, when the head 13 crosses the servo data 12 while seeking to the target cylinder, the servo data 12 is detected by the servo data detection circuit 19 through the data recording/reproducing circuit 18, and the detection circuit 19 detects the head Thirteen position signals are generated. The head positioning control circuit 16 uses this head position signal to control the head 13.
You can know the current position of the on-cylinder condition (O1
, T1) is satisfied (step S5).
, sends a seek completion notification to the controller 15 (step S6).

Further, in the data reproduction mode (step S7), the controller 15 sets the on-cylinder range to O2.
, set the on-cylinder time to T2 (step S
2) Perform a seek operation. Similarly, in the data recording mode (step S9), the controller 15 sets the on-cylinder range to O3 and the on-cylinder time to T3 (step S10), and performs a seek operation.

In this way, the on-cylinder conditions are changed for each mode, and the seek operation is performed in accordance with the conditions. Therefore, head positioning control can be performed according to the precision required in each mode. Thereby, unnecessary control can be omitted and access time can be shortened.

[0017]

As described above, according to the present invention, the on-cylinder conditions are set for each mode and the seek operation is performed according to the conditions, so that the head can be adjusted according to the accuracy required for each mode. Positioning control can be realized. Thereby, access time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a configuration according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment.

FIG. 3 is a diagram for explaining on-cylinder conditions in the same embodiment.

FIG. 4 is a diagram for explaining conventional on-cylinder conditions.

FIG. 5 is a diagram showing a track structure of a recording medium.

FIG. 6 is a diagram for explaining the accuracy of head positioning control required in each mode.

[Explanation of symbols]

11... Recording medium, 12... Servo data, 13... Head,
14...Host device, 15...Controller, 16...Head positioning control circuit, 17...VCM driver, 18...Data recording/reproduction circuit, 19...Servo data detection circuit.

Claims (1)

[Claims] Claim 1: In a data recording/reproducing device that records or reproduces data by causing a head to seek to a target cylinder, completion of a seek is determined based on at least a seek in a data recording mode and a seek in a data reproduction mode. and a positioning control means for positioning the head to the target cylinder according to the on-cylinder conditions set by the on-cylinder condition setting means. data recording and reproducing device.