JP3844086B2 - Servo writer for magnetic disk - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention relates to a servo writer of the magnetic disk for writing only the servo information on the magnetic disk.
[0002]
[Prior art]
Servo information for magnetic head position control and the like is set by a servo writer on a hard magnetic disk (hereinafter simply referred to as a disk) used for data storage in a computer system.
Normally, a disk package is configured by stacking multiple disks, and the servo information setting method for this is set to the servo surface method that dedicate one of the disks for servo information and to the track of each disk respectively. In recent small disks, there are many cases where there are two disks, and the same servo information is set in each sector of each track on the back surface. Since the servo information setting method for each disk is the same, the setting method for the surface of one disk will be described with reference to FIG.
[0003]
Figure 3 shows a conceptual diagram of a servo writer, the disk 1 is rotated θ is mounted on the spindle 2, and moves the write head h is the carriage mechanism 3 contrast, successively each track T _R of the disk 1 Seek to On the other hand, the spindle 2 is provided with a rotation angle detector 2a, which detects an index (INDX) indicating a reference point of the disk 1 and outputs an INDX signal. Seek track T _R is divided into a plurality of n sectors Sc ₁ to SC _n, starting from INDX signal is set crowded sequentially written servo information by the head h for each sector Sc.
[0004]
There are various types of servo information, and FIG. 4 is a developed view of one example thereof. In FIG. 4, servo information includes a SYNC signal for clock synchronization of the disk drive, a PC signal for controlling the position of the head h, an ID portion used for identifying a track number, a sector number, and information data used by a user. DATA section for recording.
The SYNC signal is composed of repetition codes of +1 and 0, and the PC signal is composed of alternating repetition codes of +1 and -1.
[0005]
FIG. 5 shows a block configuration of the main part of the servo writer 4, which comprises an MPU 41, a keyboard (KEYBORD) 42, a memory (MEM) 43, a carriage control circuit 44, and a write control circuit 45. Servo information is previously stored in the KEYBORD 42. Stored in the MEM 43 by operation.
In writing servo information, when the INDX signal from the rotation angle detector 2a is input to the MPU 41, a seek command is given to the carriage control circuit 44, and the carriage mechanism 3 moves the head h by this control, and the disk h 1, for example, the outermost track _TR1 is sought. Seek inputs seek end signal from the carriage control circuit 44 upon completion (SE) is the MPU 41, by the writing command, the servo information MEM43 is transferred to the write control circuit 45, for each sector Sc track T _R1 Sequentially written. When writing is completed, MPU 41 is sequentially applied seek command for each input to INDX signal to the carriage control circuit 54, and seeks each track T _R, servo information is written to each sector Sc.
[0006]
FIG. 6 shows a time chart for writing servo information.
The point to be noted here is that the PC signal pattern is alternately repeated with +1 and −1 as described above, and the servo writer 4 cannot write them simultaneously. The method is to write +1 during rotation and write -1 during the next rotation.
6, first INDX ₁ to time _{t 2} waits while seeking the track _{T R1} during the time _{t 1} as the starting point, tentatively ends at INDX ₃ to start writing of the servo information by the following INDX _2. But are +1 PC code is written to during this period, -1 so has not yet been written, the head h to the center line of the first shift to T _R1 and T _R2 half of the pitch p of the tracks T _R Seek, wait for time t ₂ , start writing −1 at INDX ₄ , end at INDX ₅ , and complete writing servo information. Hereinafter similarly seek and write each track T _R is made, the writing of the servo information for one track T _R, requires four revolutions of the disk 1.
[0007]
[Problems to be solved by the invention]
Nowadays, since the production volume has increased in response to the increase in demand for disks, it is necessary to shorten the throughput time of the servo writer.
Considering the seek time t ₁ and the standby time t ₂ described above, when the rotational speed of the disk 1 is 3600 rpm, the time t _{0 for} one rotation is about 16 ms, and the seek time t ₁ for this requires about 8 ms. and, thus the standby time _{t 2} also about 8 ms. That is, the waiting time t ₂ is reached approximately one-half of one rotation time t _0, since it is so to speak wasted time, it is effective to shorten the throughput time for omitted.
[0008]
Turning now to the contents of the servo information, the number and the sector Sc of one track T _R, the width, etc. of the recording area of the DATA portion of each sector Sc, vary with conditions such as the desired size and user disk 1 Accordingly, the number of codes of the SYNC signal and the PC signal and the code configuration of the ID part change accordingly. Whenever these change, the contents of the servo information of the MEM 43 are updated so as to correspond to this. However, since there are many repetitive codes of the SYNC signal and the PC signal, the updating operation of writing these into the MEM 43 by operating the KEYBORD 42 one by one is quite troublesome, and an efficient means to replace this is demanded.
This invention includes means for reducing the throughput time of the servo writer is omitted the standby time t _2, and eliminate the need for writing work of repetition code for MEM43, providing a means for generating a servo information efficiently Let it be an issue.
[0009]
[Means for Solving the Problems]
The present invention is a servo writer for a magnetic disk that performs servo information writing and solves the above-described problems, and includes a means for reducing throughput time and a means for efficiently generating servo information.
The throughput time shortening means uses the outermost track of the disk as the first track, moves the write head according to the index signal to seek the first track, and subsequently uses the data control method for each sector by the write control circuit. Write servo information with. There is provided a pseudo index signal generator for outputting a write end signal from the write control circuit at the end of writing and generating and outputting a pseudo index signal before the original index signal by this signal. Thereafter, seek of the second to mth tracks and subsequent writing of servo information are sequentially performed in accordance with a pseudo index signal from the pseudo index signal generator generated every time servo information is written.
On the other hand, the means for efficiently generating servo information is a command word in four arithmetic operations format that uses the number of repetitions of the signal that repeats the same code, each information content, the data recording area, etc. as parameters. A pattern generator is provided for storing the information in the memory and generating servo information in accordance with each parameter by inputting a command word. Servo information generated by inputting an execution instruction word whose parameters are determined in accordance with the use conditions of the magnetic disk to the pattern generator is input to the write control circuit and sequentially written to each sector.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Since the pseudo index signal in the present invention is generated before the original index signal is first generated in the first track, the servo information writing period in that track is shortened. For the second to m-th tracks thereafter, the pseudo index signal is generated at a point much earlier than the originally generated index signal, so the time from the seek time to the servo information writing is reduced each time.
Thus, according to the present invention, the conventional servo track writing is shortened by speeding up the servo writing by generating an index signal in the middle, and further, the writing is completed and the next original After waiting for the index signal, stop seeking to the next track, and write servo information sequentially to the track in accordance with the index signal generated in a pseudo manner after the end of writing the index signal. It is shortened.
As a result, the throughput of the servo writer can be shortened compared to the conventional case.
In detail, according to the above pseudo index signal, writes seek the servo information tracks T _R describes the processing of a servo writer in the present invention by the time chart of FIG. 1 corresponds to the time chart of FIG.
In Figure 1, the first track T _R1 of the outermost periphery, as in the conventional, but is seeking by INDX signal of the rotational angle detector 2a, in the present invention, after completion of the seek operation, in order to stabilize the head h Servo information is continuously written to each sector Sc with only a short time Δt. When the writing is temporarily completed, a write end signal is output from the write control circuit, thereby providing a Q signal generator for generating a pseudo index (hereinafter referred to as Q) signal, and the center line of _TR1 and _TR2 is _defined by the Q signal. Seek, and writing each bit of −1 of the PC code after a time Δt is completed. Similarly, each track T _R is seeking sequentially by Q signals, writing of the servo information for each sector Sc is made.
The time Δt is as short as 2 ms or less, and even if this is taken into consideration, writing to one track is completed in about three rotations of the disk 1, and the conventional four rotations are reduced to about 70%.
[0011]
Next, means for efficiently generating servo information will be described.
First, taking the servo information of FIG. 4 as an example, the above four arithmetic operation format command words will be described.
In the case of the servo information shown in FIG. 4, signals that repeat the same code are the SYNC signal and the PC signal, the SYNC signal repeat code is +1, and the PC signal repeat code is +1 and -1. Each information content is an ID part, and its code configuration is c. Since the data recording area is an area of the DATA section, the width of the area is assumed to be d. Here, the number of repetitions of servo information for one track is N ₁ , the number of repetitions of the +1 sign of the SYNC signal is N ₂ , and the number of repetitions of the +1 and −1 of the PC signal is N _3. Is determined as follows.
N ₁ * {N ₂ * + 1, N ₃ * (+ 1, −1), c, d} (1)
Here, * means x (multiplication), and each term of the instruction word (1) is stored in the MEM 43 as a binary code. In contrast, due to the desired size and user disk 1, the number of sectors Sc in one track _{T R,} i.e. the number of repetitions _{N 1} of the servo information, determines the area width d of the DATA portion, accordingly SYNC signal The code repetition number N ₂ , the PC signal repetition number N ₃ , and the code configuration c of the ID part are determined to appropriate values, and these are input to the MEM 43 to input each parameter of the instruction word (1). If you confirm, you can get the execution command.
[0012]
Next, a pattern generator is generally a hardware that cyclically outputs a digital code for a pattern such as a printed matter or a fabric in which the same pattern is repeated.
The pattern generator according to the present invention uses what generates the servo information illustrated in FIG. 4 when the execution instruction word is input, and inputs the generated servo information to the write control circuit 45. Each sector Sc is written.
As described above, only the parameters of the instruction word stored in the MEM 43 are changed according to the use conditions, and the servo information having the corresponding contents is generated in the pattern generator and used for writing. This makes it unnecessary to update the servo information.
[0013]
In addition, although the above instruction word is for the servo information of FIG. 4, the present invention is not limited to this, and if it is servo information within the range shown in claim 2, the instruction word can be defined. This servo information can be generated using a pattern generator.
[0014]
【Example】
FIG. 2 shows a block configuration of a main part of the servo writer 4 'in one embodiment of the present invention. The servo writer 4 'is configured by adding a pattern generator 46 and a pseudo index signal (Q) generation circuit 47 to the conventional servo writer 4 of FIG. 45 is provided with a function of outputting an end signal WE at the end of writing of servo information (including writing on the minus side of the PC code). The instruction word (1) is stored in the MEM 43, and each parameter is determined according to the use conditions and used as an execution instruction word.
[0015]
Hereinafter, the writing operation of the servo writer 4 'will be described with reference to FIG.
The first track T _R1 of the outermost periphery, the rotation angle detector 2a is seek by INDX signal, input to the seek end signal SE is output MPU41 from carriage control circuit 44 at this end, the execution of MEM43 by the command instruction word is transferred to the pattern generator 46, and input to the write control circuit 45 servo information is generated _once N, +1 N ₂ times of the SYNC signal to each sector Sc, at a time +1 N ₃ times PC signal Each is written, and the code configuration c of the ID part and the area width d of the DATA part are set. At this time, the write end signal WE is output from the write control circuit 45 to the Q generation circuit 47, the Q signal generated by this is input to the MPU 41, a seek command is issued to the carriage control circuit 44, and the head h is seek centerline of T _R1 and T _R2, then the write control circuit 45 pattern generator 46 outputs a -1 PC signal is a write N ₃ times to each sector Sc in writing is completed. Similarly, for each track T _R, a seek by Q signals, and the generation of the servo information pattern generator 46, a write for each sector Sc is sequentially performed.
[0016]
【The invention's effect】
As described above, in the servo writer of the magnetic disk for writing servo information according to the present invention, the waiting time in the conventional writing method is omitted, and the throughput of the servo writer is shortened compared to the conventional one. The adoption of the command word and the pattern generator eliminates the need to update the servo information for the conventional memory, and has an excellent effect that contributes to improving the productivity of the magnetic disk.
[Brief description of the drawings]
FIG. 1 is a time chart for explaining a servo writer of a magnetic disk for writing servo information by a pseudo index signal.
FIG. 2 is a block diagram of a main part of a servo writer for a magnetic disk in one embodiment of the present invention.
FIG. 3 is a conceptual diagram of a servo writer.
FIG. 4 is a development view of an example of servo information.
FIG. 5 is a block diagram of a main part of a conventional servo writer.
FIG. 6 is a conventional time chart for writing servo information.
[Explanation of symbols]
1 ... magnetic disk, 2 ... spindle, 2a ... rotation angle detector,
3 ... carriage mechanism,
4 ... conventional servo writer, 4 '... servo writer according to the present invention,
41 ... MPU, 42 ... Keyboard (KEYBORD), 43 ... Memory (MEM),
44 ... Carriage control circuit, 45 ... Write control circuit, 46 ... Pattern generator 47 ... Pseudo index (Q) signal generator,
T R _... track, h ... magnetic head (head), SE ... seek end signal,
WE: Write end signal, p: Track pitch.

Claims (1)

A plurality of m tracks set on the magnetic disk are divided into a plurality of n sectors on the basis of the index signal, and each track is sequentially sought by a magnetic head. In a servo writer for a data surface type magnetic disk in which servo information stored in advance in a memory is written by a write control circuit,
The outermost track is the first track, the magnetic head is moved by the index signal to seek the first track, and the servo information is subsequently written to each sector by the write control circuit. And a pseudo index signal generator for outputting a pseudo index signal before the original index signal by the write end signal, and outputting the pseudo index signal by the write end signal. In accordance with the pseudo index signal from the pseudo index signal generator generated at the end of writing of information, seek of the second to mth tracks and subsequent writing of servo information are sequentially performed ,
The servo information, the number of repetitions of the signal repeating the same code, each information content, data recording area, etc. are defined as four arithmetic operation instruction words, respectively, and the instruction words are stored in the memory, In addition, a pattern generator that generates servo information according to each parameter by inputting the command word is provided, and an execution command word in which each parameter is determined according to the use condition of the magnetic disk is input to the pattern generator. A servo writer for a magnetic disk, wherein servo information generated in this manner is input to the write control circuit and sequentially written in each sector.

Images