CN1178024A - Method and system for writing servo-pattern on storage medium - Google Patents

Abstract

A technique for writing a servo mode onto a storage medium (12a) located in a recording device (10) having an internal recording head (14a). A timing pattern is generated on the storage medium (12a) using the internal recording head (14a), and a radial positioning value is determined to radially position the internal recording head (14a). The servo mode is written using the internal recording head (14a) at the position determined by the timing pattern and the radial positioning value.

Description

Method and system for writing servo patterns on a storage medium

The present invention relates generally to recording devices, and in particular to the operation of writing servo patterns on storage media without the use of external sensors.

Information for a system, such as a data processing system, is typically stored on a storage medium, such as a magnetic disk. When disks are manufactured, a disk drive with multiple internal heads is usually installed in a master station called a servo writer. The servowriter has sensors external to the disk drive for positioning the radial and peripheral position of at least one magnetic head for writing a pattern of magnetic information onto a disk surface coupled to the write head. Disk drives use this pattern as a master reference signal in normal operation to locate tracks and sectors for data storage.

The on-station servo writing process is expensive since each magnetic drive must be serially installed in the servo writer. Furthermore, the mechanical boundary conditions of the disk are changed when the sensor has to access the actuator and the spindle motor. This may require the disk to be clamped and disassembled mechanically.

One process for writing servo information is described in US Patent 4,414,589, entitled "Embedded Servo Track Following System for Writing Servo Tracks", issued November 8, 1983 and assigned to Northern Telecom, Inc. A servo track following system for positioning a moving read/write head relative to a magnetic storage disk is described in US Patent 4,414,589. A plurality of servo tracks are recorded in a sector on the disc to identify radial positions or information tracks. Write a single pulse on a fixed clock track head to write a clock track, apply a phase locked loop to an intermediate clock track written on a moving head, and then apply a lock to a final clock track written on a fixed clock track head phase ring. The radial track density is determined by moving a head to the limit stop and writing a reference track. The head is then moved away by a sufficient amount to reduce the reference track amplitude by a predetermined percentage relative to the maximum average track density. Thereafter, another reference track is written and the head is moved away from the second reference track by a sufficient amount to further reduce the amplitude of the reference track by a predetermined percentage. This continues until the disc is filled with reference tracks. If the average track density thus obtained is not satisfactory, adjust the reduction and repeat the above process.

Another technique for writing servo information is described in US Patent 4,531,167, entitled "Servo Writing System for Disk Drive," issued July 23, 1985 and assigned to Pioneer Research, Inc. In US Pat. No. 4,531,167, prior to writing a servo track to the disc, a master clock track must first be written to the disc by a separate head, which serves as a timing reference signal for the entire operation. Even (EVEN) servo information is written on the entire surface of the disc, that is, servo bursts are written on the disc. This is accomplished by first moving the arm to the outer bump stop, and then moving the arm radially a distance less than the data track width per revolution of the disk. With the rear arm moved away from the outer bumper, the head is used to write odd numbered (ODD) servo information into a number of sectors of the disk drive. When the arm for writing odd number (ODD) servo information reaches the inner diameter of the disc, the number of steps the arm has taken from the outer bumper to the inner bumper is compared to the number of tracks actually required on the disc. If the actual number of steps differs from the actual number of tracks required, a specific offset number determined by the microprocessor is used so that the number of steps in the next operation is exactly the same as the number of tracks required on the disk.

Each step in the above process requires an external timing sensor to write the timing pattern used in determining the peripheral position of the head. Also, due to the need for external sensors, there must be a clean indoor environment. Also, in order to determine the track pitch used when writing the servo pattern later, the loading information should be written. This is time consuming and expensive. There is therefore a need for a technique for writing servo patterns to discs that does not require a clean room environment. Furthermore, there is a need for a technique for writing servo patterns that does not require an external sensor. There is also a need for a method for determining which head in a recording device writes the widest track. There is also a need for a method for determining the track pitch of a recording device without having to write the entire disc. There is also a need for a technique for writing timing information that eliminates an external clock source, thereby reducing the likelihood of errors due to relative motion between the head writing the servo pattern and the clock source.

A method for writing a servo pattern on a storage medium in a recording device having an internal recording head overcomes the disadvantages of the prior art and provides additional advantages. A timing pattern is generated on the storage medium with the inner recording head, and radial positioning values for radially positioning the inner recording head are determined. The servo pattern is written at the position determined by the generated timing pattern and radial positioning value.

In one embodiment, to generate a timing pattern on a storage medium having a plurality of tracks, a plurality of transitions are written on the first of the plurality of tracks, the time interval between each pair of transitions in the plurality of transitions is determined, and each determined The amount of deviation between the time interval of , and the predetermined normal interval and the number of transitions are written on the second of the many lanes. Each first portion of the plurality of transitions is written at a first predetermined time delay and each second portion of the plurality of transitions is written at a second predetermined time delay.

In another embodiment, the track pitch of a recording device having N-track storage media is determined. A transition is written on a number of N tracks, a readback signal associated with each written transition is obtained, and the readback signals are compared to determine track pitch.

In yet another embodiment, it is determined which of a plurality of recording heads in a recording device writes the widest. The first transition is written using each of the plurality of recording heads and the second transition is written using one of the plurality of recording heads. The second transition written is spaced a predetermined distance from the first transition written using the same recording head used to write the second transition. Each recording head is positioned using the second transition and an amplitude signal associated with each first transition is read and compared with the positioned recording head. The widest written recording head is determined from the comparison result.

In another embodiment, a timing pattern is generated on one of a plurality of storage media located in a recording device having a plurality of internal recording heads. Each of the plurality of storage media has associated with it at least one of the plurality of internal recording heads. Using the first of many internal recording heads to write represents the first of many transitions in the timing pattern. The first and second of numerous internal recording heads are positioned. A first plurality of transitions is read with a first positioned recording head and a second plurality of transitions is written with a second positioned head. The first and second recording heads are repositioned and the second plurality of transitions is read with the repositioned second recording head, and the third plurality of transitions is written with the repositioned first recording head.

In another aspect of the present invention, a system for writing a servo pattern on a storage medium located in a recording device is provided. The system includes means for generating a timing pattern on a storage medium using an internal recording head, means for determining radial positioning values for radial positioning of the internal recording head, and means for writing a servo pattern on the storage medium using the internal recording head device. The servo pattern is written at the position determined by the timing pattern and radial positioning value.

In another aspect of the present invention, a recording device is provided. The recording device includes a storage medium within the recording device and an internal recording head within the recording device for writing timing information and servo patterns on the storage medium. In one embodiment, the recording device is sealed.

The technique of the present invention allows servo patterns to be written on storage media without the need for external sensors or clean room environments. Furthermore, there is provided a technique for determining the track pitch of the recording device without requiring writing of the entire disk information. Additionally, writing to timed patterns does not require an external clock source. The technique of the present invention enables timing information and servo patterns to be written easily and more accurately than before.

What is claimed is the invention which is particularly pointed out and distinctly set forth in the claims at the conclusion of the specification. The foregoing and other objects, features and advantages of the present invention will be more apparent from the following detailed description in conjunction with the accompanying drawings, in which:

Figure 1a illustrates an example of a disk drive incorporating the technique of writing servo patterns of the present invention;

Figure 1b illustrates an example side view of a disc drive having a plurality of recording discs in accordance with the principles of the present invention;

Figure 2 illustrates an example logic diagram associated with the technique of the present invention for writing servo patterns;

Figure 3 illustrates an example logic diagram associated with a technique for determining the head to write the widest track in accordance with the principles of the present invention;

Figure 4 illustrates an embodiment of dividing a disk surface into N peripheral pie-shaped portions according to the principles of the present invention;

Figure 5 illustrates an example of a plot of signal amplitude versus off-track position of the recording head in accordance with the principles of the present invention;

Figure 6 illustrates one embodiment of a logic diagram associated with techniques for determining track spacing in accordance with the principles of the present invention;

Figure 7 illustrates an embodiment of dividing the disk surface into N peripheral pie-shaped sections and writing four bursts in one section according to the principles of the present invention;

Figure 8 illustrates an example of a plot of readback signal amplitude versus radial position of a recording head having a correct track pitch in accordance with the principles of the present invention;

Figure 9 illustrates an example of a plot of readback signal amplitude versus radial position of a recording head having an incorrect track pitch in accordance with the principles of the present invention;

Figure 10 illustrates one embodiment of a logic diagram associated with writing timing patterns on a disc located within the disc drive of Figure 1 in accordance with the principles of the present invention;

Figure 11 illustrates an example of a non-repeatable speed jitter spectral density curve for a disk drive;

FIG. 12 illustrates an example curve of jitter versus time interval for the disk drive of FIG. 11;

FIG. 13 illustrates an example of a curve of jitter RMS versus step count according to the principles of the present invention;

Figure 14a illustrates a radial timing mark track in accordance with the principles of the present invention, wherein no fraction is added to the normal time interval when even transitions are generated from odd transitions;

Figure 14b illustrates a radially timed mark track in accordance with the principles of the present invention, where a fraction of 1 is added to the normal time interval when even transitions are generated from odd transitions;

Figure 14c illustrates a radially timed mark track in accordance with the principles of the present invention, wherein a time-varying fraction of 1/2 is added to normal time intervals to generate even transitions from odd transitions;

Figure 15 illustrates an example of a curve describing displacement error versus number of steps in the direction of a radial timing mark in accordance with the principles of the present invention;

Figure 16 illustrates an example logic diagram associated with writing servo patterns on a disc surface in accordance with the principles of the present invention;

Figure 17 illustrates an example logic diagram for propagating the servo pattern of Figure 16 to other disk surfaces in accordance with the principles of the present invention;

Figure 18 illustrates one embodiment of a logic diagram for writing timing information on a disk surface using two heads in accordance with the principles of the present invention.

In accordance with the principles of the present invention there are provided methods and apparatus for writing servo patterns on a storage medium. In one embodiment, a servo pattern is written to one or more disks located in a recording device such as a disk drive. 1a and 1b, in one example disc drive 10 includes one or more magnetic discs 12a-12b (collectively referred to as disc 12), one or more internal recording heads 14a-14d (collectively referred to as recording head 14) , a suspension mechanism 16, an actuator 18, an actuator holder 20, one or more crash barriers 22, an actuator driver 24, a read/write controller 26, a computer 28, a programmable delay generator 30 and a time interval measuring system 32. Each of these components will be described in detail below.

Each magnetic disk has, for example, two surfaces capable of receiving information, and each surface has a plurality of tracks 13 . In accordance with the principles of the present invention, internal recording head 14 is used to write information such as timing information and servo patterns on the surface of one or more magnetic disks 12 . A spindle motor 5 ( FIG. 1 b ) is located at the inner diameter of the disk 12 and is used to rotate the disk 12 as is known in the art. The recording head 14 is fixed to the suspension mechanism 16 as illustrated in FIG. 1 a.

Suspension mechanism 16 allows the recording head to move in the vertical direction and is attached to actuator 18 . The actuator 18 is, for example, a standard moving coil actuator comprising a ball bearing 19 connected to a voice coil motor 23 . As shown in FIG. 1 b , the motor 23 includes one or more magnets 21 . On either side of the ball bearing 19 there is a crash stop 22 which serves to limit the range of movement of the transmission. The actuator 18 is mounted on the base plate 25 through the actuator holder 20 . In one example, the actuator holder 20 secures the actuator to the base plate with one or more screws.

Actuator driver 24 is connected to base plate 25 by a line 27a and includes electronic circuitry for supplying current to voice coil motor 23, such as power transistor circuitry.

Also connected to the substrate 25 by a line 27b is a read/write controller 26 for reading and writing magnetic transitions on the disk, as will be described below in accordance with the principles of the present invention.

Computer 28 is connected to read/write controller 26 and actuator driver 24 via buses 29a and 29b, respectively. Computer 28 comprises, for example, a standard personal computer with memory for storing information.

Programmable delay generator 30 is connected to computer 28 via IEEE bus 31 . Programmable delay generator 30 is, for example, a Hewlett Packard HP8118A generator for controlling the timing at which a given transition is written, as will be described in more detail below.

A time interval measurement system 32 is also connected to computer 28 via IEEE bus 33 for measuring desired time intervals in accordance with the principles of the present invention. In one embodiment, the time interval measurement system 32 includes a time analyzer model HP5372A supplied by Hewlett Packard.

Those skilled in the art know that many modifications can be made to the disc drive illustrated in Figures 1a and 1b. For example, a disk drive may have only one disk or only one recording head.

In accordance with the principles of the present invention, a disc drive 10 is used to write servo patterns on one or more magnetic discs 12 . Servo patterns are written at specific locations on one or more disk surfaces, so radial and peripheral positioning information (θ) is determined for the recording head used to write the servo patterns prior to writing the servo patterns. An example of a technique for writing a servo pattern is described in detail below.

Referring to FIG. 2, in one embodiment it is determined which recording head of the disk drive 10 writes the widest track, step 50 "determine widest head". In this embodiment, the head for writing the widest track is the head required for writing the timing pattern and the servo pattern, which will be described in detail below. If there is only one recording head, then that head is the one that writes the widest track. The method of determining the widest head will now be described in detail with reference to FIG. 3 .

Referring to Fig. 3, according to the principles of the present invention, in order to determine which recording head of a disk drive or other recording device writes the widest track, each disk surface located in the disk drive is divided into N peripheral pie-shaped parts, that is, step 52 " divides each A disk is divided into N peripheral pie-shaped parts". In one example N is set to sixteen, so the disk surface is divided into sixteen peripheral pie-shaped portions, as shown in FIG. 4 . As is known in the art, to divide the disk surface, a mark is used to identify the first sector. Thereafter any number of sectors can be defined by writing the pattern at a predetermined distance from each other.

With reference to Fig. 3 and 4, after dividing each plane into N sectors, every other sector is marked as A sector and the rest are marked as B sector, that is, step 54 "every other sector is marked as "A" and the remaining sectors are labeled "B". Thereafter, each recording head 14 is used to write a train of amplitude pulses (ie, one or more magnetic transitions) on the corresponding disk surface with the actuator 18 against the crash stop 22 . Specifically, according to the principle of the present invention, the amplitude pulse train is written in each "A" sector of the first track on the disk surface, that is, step 56 "use all heads to write in the "A" sector of #1 track Amplitude Pulse Train".

After writing the information burst, the actuator 18 is moved a predetermined distance, step 58 "move actuator a predetermined distance". In one embodiment, the predetermined distance is determined based on the signal amplitude of a recording head, such as recording head 14a, in relation to the position of the head over the track. An example of an approximately linear relationship between amplitude and position above the trace is illustrated in FIG. 5 . As shown in Figure 5, when the amplitude is at its maximum value, the recording head is directly on the track (i.e., 30 microns), while when the recording head is at half its maximum amplitude value (i.e., approximately 0.5), the recording head is approximately at Half way outside the track (i.e. 15 microns). In one example, the actuator is moved until the readback signal from head 14a is equal to half of its maximum amplitude (ie, the off-track half position). When the sampling of the rectified head signal is servoed to the half-amplitude position, use the head 14a to write the amplitude pulse train in the B sector on the second track of the disk surface corresponding to the head 14a, that is, step 60 "use the head 1 at # Amplitude bursts are written in sector "B" of track 2.

By radially departing from the second track, the "B" burst can be used to provide position information. For example, the head may be gated to read signals from magnetic transitions corresponding to a particular period "B" burst (amplitude burst). Using a sample-and-hold circuit keeps the voltage corresponding to the amplitude of the readback signal constant in the interval between bursts. This produces an appropriate positioning signal that is input to the servo loop to position the actuator. In one embodiment, a servo control loop with a low frequency band is used when servoing to a given amplitude of the readback signal. Then, the head position is the average of all sector bursts, rather than following the repeatable variation of the magnetic servo signal. Using the "B" burst amplitude as the position signal for the servo system (i.e., servo operation), the amplitude signals from the "A" burst under all recording heads of the disc drive are read and compared, i.e. step 62" compare "A" burst signal". The signal from the "A" pulse train is read and compared in one example using a standard measurement tool such as a voltmeter or digital oscilloscope. When signals are lost for all but one head, the only head is determined to be the head that writes/reads the widest lanes.

Although the examples described above use numerous "A" and "B" bursts, only one "A" burst and one "B" burst can be used.

Referring back to FIG. 2, in one embodiment, after determining the head that writes the widest track (hereinafter referred to as head W), it is used to determine the track pitch of the disk drive according to the principles of the present invention, step 64 "determine track pitch" .

Referring to Figures 6 and 7, in one embodiment, in order to determine the track pitch of the disk drive, the disk surface corresponding to the head W is divided into N peripheral pie-shaped portions, ie step 70 "divides the disk surface". As shown in FIG. 7 , in one example, the disk surface is divided into 16 sections 68 and each section 68 has a plurality of tracks 71 . Typically a platter has a track density of about 4000 tracks per inch (ie 2000 data tracks, where one data track is twice as wide as one track so that one data track does not overlap another data track).

Referring again to Fig. 6, after dividing the disc surface, the driver 18 is leaned against the collision barrier, and the amplitude pulse train called "A" pulse train is written on the first track of each part with the head W, that is, step 72 " Write "A" burst on track #1 with head W" (see Figure 7). (In another embodiment, it is possible to write the "A" burst on the first track using a head other than the head that writes the widest track. Also, it is possible to write the burst on other tracks than the first on the track.) After writing the amplitude burst, the actuator 18 is moved a predetermined distance so that the amplitude from the head writing the widest track is half the maximum value or an amplitude that best guesses the inter-track spacing , that is, step 74 "positioning the actuator".

After positioning the actuator, hold the actuator in that position and write the "B" burst on the second track of each section, step 76 "Write "B" burst on track #2 with head W" . Similarly, with the servo working on the "B" burst, the "C" burst is written on the third track of each section, i.e. step 78 "Write "C" burst on track #3 with head W" and The servo operates on the "C" burst and writes the "D" burst on the fourth track of each section, step 80 "write "D" burst on track #4 with head W".

After the four bursts (A, B, C, and D bursts) are written on the track using the head that writes to the widest track, the readback signal from each burst can be compared to determine the track pitch, ie the step 82 "Comparing readback signals from bursts A, B, C, D". If the track pitch is at the desired level, then when the head W is over the center of the second track, the readback signal from the "B" burst is at a maximum and there is no amplitude signal from the fourth track. That is, if the track pitch is equal to the head width, then the amplitude from the "D" burst is below a threshold set close to zero, for example -40dB below the on-track amplitude. Furthermore, the signal from both the "A" and "C" bursts is equal to the amplitude that was servoed when writing the second track. An example of this is shown in Figure 8, where the "B" train, marked at reference numeral 83, has the greatest amplitude, the "D" train has a near-zero amplitude and the "A" and "C" trains have equal amplitudes .

If the track distance is correct, that is, the affirmative answer of query 84 "is the track distance correct?", then the process ends, that is, step 85 "end", the amplitude of the "A" pulse train servoed when writing the "B" pulse train Called Q1, as will be described below, Q1 is used to write the servo pattern. However, if the readback signal is as shown in FIG. 9, the track pitch is too large, so a new "A" burst amplitude is determined as described below, step 86 "determine new amplitude of "A" burst ".

Specifically, referring to FIG. 9, Q1 represents the amplitude of the "A" burst that is servoed when the "B" burst is written. At this location (R1), the signal from the "D" burst is still not close to zero. Servo to a new position R2 where the signal from the "A" burst is equal to Q2 and the signal from the "D" burst drops to a predetermined threshold near zero. In this position, the signal from the "C" pulse train is equal to Q3. Therefore, it can be concluded that Q2>Q1>Q3 at any time when the track distance is too large. Similarly, if the track pitch is too small, then Q2<Q1<Q3.

As above, if the track pitch is incorrect, a new amplitude _Q1new is determined for the "A" burst. In one embodiment, to determine the new amplitude of the "A" burst, the following equation may be used. If the readback signal is linear in the region of amplitude Q1, then:

Q1 _new ＝1/2(Q3+Q1 _old )

Referring back to FIG. 6, after determining Q1 _new , the flow proceeds to step 72 "write "A" burst on track #1 with head W". (Here Q1 or Q1 _new are radial positioning values.) After writing the "A" burst, position the actuator so that the amplitude from the head writing the widest track is equal to Q1 _new , ie step 74" Position the actuator". In this position a "B" pulse train is written on the second track using the head writing to the widest track. Thereafter the flow continues as previously described.

In another embodiment, the value of Q1 or Q1 _new is updated every predetermined number of tracks, even if the values of Q1 or Q1 _new of all tracks are normally unchanged.

As described further below, a Q1 or Q1 _new value representing a proportion of the amplitude on the track is used to write the servo pattern. However, referring back to FIG. 2, prior to writing the servo pattern, timing marks are generated which are used to peripherally mark the placement of the pattern, step 90 "Generate Timing Mark". In one example, the timing pattern includes a set of equidistant radial timing marks of magnetic transitions produced in accordance with the principles of the present invention. The timing patterns, as well as the servo patterns described below, can be written with the internal recording head in the sealed disk drive. No external sensors are required.

Referring to Figure 10, a technique for writing a timing pattern on disc 12 is described in detail. In one embodiment, the internal recording head used to write the timing pattern is the head that writes the widest track. Initially the head W leans against a limiter (i.e. the collision barrier 22) at the innermost position of the disc (hereinafter referred to as the disc W) associated with the head W, that is, step 92 "put the head against the limiter" . When the head is in this position, a sequence of transitions or a sequence of transition pulse trains (such as magnetic transitions) is written on the disk at equal time intervals during the disk cycle, that is, step 94 "write transitions on track #1 of the disk". In one example, the rotational speed of the disk is 60 rpm, and a time interval of 92.56 microseconds is chosen to write 180 transition bursts on one track of disk W. The 180 transition bursts can be viewed as pairs of transitions, where each pair includes an odd transition and an even transition, respectively. For example, a pair of transition bursts includes bursts 1 and 2 . Another pair includes bursts 3 and 4, and so on.

After the write transition, specifically, on the second revolution of disc W, the time interval between each odd and even transition burst (1-2, 3-4, etc.) is measured, step 96" Measure the time interval between odd and even transitions". In one embodiment, to measure the time interval, a time interval measurement system 32 is used. After measuring each time interval, the computer 28 determines the deviation of each time interval from the normal interval, eg, 92.56 microseconds. Specifically, the computer 28 subtracts each time interval from the normal interval value to obtain deviation values, and then stores these deviation values in the memory of the computer 28, that is, step 98 "store the deviation of each time interval from the normal interval" .

In one embodiment, a specific normal value is determined for the time interval between transition 180 and transition 1, step 100 "measure interval between last and first transition". Since the interval between transition 180 and transition 1 is much different from the normal interval of 92.56 microseconds (ie, microseconds instead of nanoseconds), a special normal interval is established. The reason for this is that transitions 180 and 1 are written 16.67 milliseconds apart instead of 92.56 microseconds apart. After the special normal value is determined, it is stored in computer memory for use as the interval between transition 180 and transition 1, step 102 "store interval as special normal value".

After writing the transition pulse train (or transition sequence in another embodiment) on a track and determining and storing the offset value, the head W is moved radially away from the first track by a predetermined amount, step 104 "turning the head Move Predetermined Value". In one embodiment, the predetermined value is approximately equal to half the track width. After moving the head about half a track, the existing odd transitions are used as trigger points to write a new set of even transitions with head W, step 106 "write information on next track with odd transitions". The time at which a given even transition is written is controlled by the programmable delay generator 30 (FIG. 1) and is equal to the normal interval plus a fraction of the stored measured deviation for this pair of transitions, eg one-half. After the even transition is written, a new set of odd transitions is generated using the even transition as a trigger point, ie step 108 "write information on next track with even transition". Similar to writing of even transitions, a given odd transition is written at a time controlled by a programmable delay generator. In this case, the delay generator for a given transition pair is set equal to the normal interval for that pair. In addition to the above, generate transition 1 from transition 180 and write it on the second track. In this case, the programmable delay generator is set to the particular normal value calculated above plus half the measured offset value located in memory for this pair of transitions. For the second pass this bias is zero, but not for subsequent passes.

After writing the even and odd transitions, the time intervals of each pair of odd-even transitions are measured and the deviation of each interval from the normal time interval (or a particular normal interval) is stored in a memory located in the computer 28, step 110" Measure the interval and store the bias".

Thereafter, it is determined whether there are more tracks on the disc to receive timing information, that is, query 112 "more tracks?". If there are no more tracks on the disc to receive timing information, then the process of placing the timing pattern on the disc is complete, step 114 "END". However, if the timing pattern is to be written on an additional track of the disc, the flow returns to step 104 "move head by predetermined value" and the process is repeated.

Use the procedure described above to provide equidistant radial timing marks that can be used as trigger points for generating servo patterns. In one example, servo pattern information is written in the area between the radial timing marks. After the servo pattern is written, the radial timing marks can be erased. Additionally, the servo pattern can be written without every radial timing mark.

In accordance with the principles of the present invention, it is desirable to start the servo pattern as early as possible after one radial timing mark to minimize timing jitter. The time required to switch the head from a read operation to a write operation determines the minimum possible time, which is typically less than 1 microsecond. Timing jitter between recorded transitions can be caused by rotational speed variations, vibration of the recording head, electrical noise and media noise. (Media noise is typically less than 1 ns rms on good media, so it can be ignored in the context of servo writing). The detailed performance of jitter is determined by the specific mechanical design of the disc, as well as the quality of the disc velocity control. The technical performance of Hardcard disk drives was measured as representative of the magnitude and frequency spectrum of jitter expected in typical low-end disk drives. An HP 5372A time analyzer was used to acquire a continuous sequence of 4096 time intervals of the 10KHz recorded pattern. Reciprocate each time interval to obtain a record of velocity versus time. The data is then combined into individual revolutions and averaged to obtain a repeatable fraction of jitter. The repeatable portion of the jitter is subtracted from the data and Fourier transformed to obtain the non-repeatable velocity jitter. Hardcard's non-repeatable velocity jitter spectral density is illustrated in Figure 11. As shown in the figure, most of the jitter occurs at lower frequencies, probably caused by changes in motor speed. Several spikes were observed at higher frequencies (1900 and 2800 Hz), caused either by hanger resonances or by ball bearing defects.

Since most of the speed jitter occurs at frequencies below about 30 Hz, the jitter of the time interval is linearly proportional to time intervals shorter than about 30 milliseconds. The linear relationship in Figure 12 illustrates the rms value of jitter in nanoseconds versus the time interval in milliseconds, which is obtained by summing the groups of intervals in a long sequence of records and computing the longer The jitter rms value of the interval. In one example, for an interval of 92.56 microseconds, the jitter is calculated to be 4.9 nanoseconds rms. This value is slightly above linear scaling due to electronic noise, which limits the maximum jitter to about 3 nanoseconds at zero interval in this particular disk drive. The data generated in the experiments described above demonstrate that servo pattern information, such as servo domain gray codes or phase bursts, can be aligned within nanoseconds by triggering outside the well-established radial timing mark pattern.

In any self-propagating mode scheme, this same minimum error applies to each cycle of the process. In general, such a process constitutes a "random walk" in which the pure error grows as the square root of the number of periods. For a process containing 2000 cycles and an error of 4.9 nanoseconds per cycle, the model error will be 219 nanoseconds. Since the typical magnetic pattern period in a gray code or phase train is about 200 nanoseconds, this error is completely unacceptable. In accordance with the principles of the present invention, when a write-time pattern is written using the process described above, the pattern error along each radial timing mark is approximately equal to twice the minimum error per week, independent of the number of cycles. (The errors in the absolute position of the radial timing marks are indeed cycle related, but only increase as the fourth root of the cycle. These errors do not affect gray code or phase burst configuration). So a 4.9 nanosecond error per week only produces a pattern error of about 10 nanoseconds, which is only 5% of the magnetic pattern period, a modest amount. In addition, there is potential for improved pattern accuracy with existing methods of writing servos, where timing can be provided by a separate clock head or a rotary encoder. In such systems, the relative physical motion between the clock source and the write head creates timing errors. This motion can be caused by vibration of the structure holding the head or non-repeatable wobble of the shaft. For a head located at a one-inch radius on a platter spinning at 3600 RPM, a relative motion of 3.7 microinches would cause a timing error of 10 nanoseconds.

As previously described, in accordance with the principles of the present invention, a timing delay of a predetermined value is used when writing a timing pattern. In one example, the predetermined value is equal to the normal value plus a fraction of the measured deviation (labeled F). In a preferred embodiment this fraction is 1/2, according to the comparison of the following three cases:

F=0; F=0.5; and F=1.

Fig. 13 illustrates the curves of the root mean square value of jitter and the number of steps at the positions of 180 radial lines around a track in the above three cases. As shown in Figure 13, for example, there are 1000 steps in the figure and each step corresponds to a half pass. The data in the curve is the average of the results of eight different MonteCarlo experiments. (The Monte Carlo technique is a computer simulation for evaluating processes governed by random events and is familiar to those skilled in the art). The error at the generation of the initial trace (eg, trace number one) is selected from a Gaussian distribution with a standard deviation of 4.9 nanoseconds to correspond to Hard Card jitter measured at 92.56 microsecond intervals. Added error when generating new even transitions with Nanosecond standard deviation to account for additional effects of the measurement process. A 4.9 nanosecond error was used when generating odd transitions from even transitions. From this log-log plot it can be seen that the propagation of the control error is completely different for F=0 or 1 and F=0.5.

For the case of F=0, the different propagation paths consist of completely independent random walks that spiral outward on two azimuthal lines for each outward step (see Figure 14a). For such a process the rms error grows with the square root of the number of steps. For F=1, the error propagates along independent radial paths and again grows with the square root of the number of steps (Fig. 14b). However, for F = 0.5, the errors are continuously mixed between the spiral and radial paths (Fig. 14c), resulting in a random walk of a different nature that grows with the fourth root of the number of steps. In Figures 14a-14c, the maximum radius corresponds to 200 steps and the angular deviations are magnified by a factor of 200 to make them visible.

Timing errors along the radial timing marks directly affect the configuration of adjacent gray code transitions or phase bursts. If the errors are large enough, the readback amplitude of the radial timing marks themselves will deteriorate. Qualitatively, as illustrated in Figures 14a-14c, such errors appear as jagged individual lines. It can be seen that this type of error is much larger when F=0 than in any of the schemes using error measurement and correction (such as F=1 and F=0.5). Quantitative results are presented in Figure 15, where the root mean square value of the offset between adjacent steps along the radial timing marks is plotted against the number of steps. As before, these values are the average of eight different experiments. For F=0, the step-to-step error caused by the spiral propagation path is even larger than the absolute position error around a track. For both F=1 and F=0.5, the step-to-step error is constant (independent of the number of steps) and approximately equal to twice the fundamental interval noise of 4.9 nanoseconds.

It should be noted that the total timing pattern error is proportional to the jitter in the base interval used. Errors can be significantly reduced by improving motor speed control and using better readback signal conditioning. Radial timing mark mode, which uses transition bursts rather than separate transitions, may also further reduce electronic component jitter. Reduced electronics effects can be further improved by using shorter base spacing between radial timing marks.

According to the principle of the present invention, the total time required to generate the radial timing mark pattern is estimated to be about 2 minutes for one pattern (including 1000 tracks, ie 2000 steps). This is based on the assumption that each propagation step takes four turns to complete; each turn is used for half-track head movement, writing even transitions, writing odd transitions, and measuring the odd-to-even interval.

It will be obvious to those skilled in the art that a series of changes can be made in the above-described process without departing from the spirit of the invention. As an example, other error corrections (ie, fractions of the measured deviations) may be used instead of half. As another possibility, partial error correction can be used in generating odd transitions from even transitions. In experiments it was found that this had no effect on the absolute position error around a track, but slightly reduced the step-to-step offset error along the line.

Described above is a technique for writing clock track information on a disk surface using an internal recording head of the disk drive. Referring back to FIG. 2, after the timing pattern is generated, the servo pattern is written, step 120 "Write Servo Pattern on One Side".

Referring to Figure 16, a technique for writing servo patterns using a head writing the widest track and a fraction of the on-track amplitude (ie Q1 or Q1 _new ) used to provide radial positioning of the head is described in detail. Specifically, the head (that is, head W) that writes the widest track returns to the collision barrier at the innermost track of the disk surface (that is, surface W) associated with head W, that is, step 122 "moves the head to the limit device".

A pulse train of amplitude "A" is written at this location, step 124 "Write "A" pulse train". Toggle every third timing mark (eg, timing mark 1, 4, 7, etc.) to write an amplitude "A" burst with a normal delay of 30 microseconds and a width of 10 microseconds. That is, a pulse train of amplitude "A" is written 30 microseconds after the timing mark and has a duration of 10 microseconds. Those skilled in the art know that the burst can be written after every timing mark or at any desired period, with every third timing mark being just one example.

After writing an "A" burst every third timing mark, the head W is servoed on the initial "A" burst at the radial position represented by Q1 or Q1 _new , as described above, step 126 "Servo head". When the head W is in this radial position, a pulse train of amplitude "B" is written at the peripheral position represented by every third timing mark (2, 5, 8, etc.), that is, step 128 "write" B "Pulse train". A "B" burst of width 10 microseconds is written after a normal delay of 1 microsecond after every third timing mark.

After writing the amplitude "A" and "B" bursts, every three timing marks (1, 4, 7, etc.) trigger once to write a sector header, that is, step 130 "write sector track ". The sector header, including a servo identification field and gray code information, is written with a normal delay of 1 microsecond and a total duration of less than 29 microseconds.

After the sector header is written, head W, as defined above, is servoed to the signal level ratio of Q1 or Q1 _new on the amplitude "B" burst, step 132 "Servo Head". When head W is in this radial position, every third timing mark (1, 4, 7, etc.) triggers to write a burst of amplitude "C" with a normal delay of 40 microseconds and a width of 10 microseconds , that is, step 134 "write "C"burst".

Thereafter, the head W is servoed to the signal level ratio of Q1 or Q1 _new on the "C" burst, step 136 "Servo Head", and is triggered every third timing mark (2, 5, 8, etc.) A pulse train of amplitude "D" is written with a normal delay of 10 microseconds and a width of 10 microseconds, step 138 "Write "D"burst".

After writing the "C" and "D" bursts, a sector header is written, step 140 "Write Sector Header". Similar to the writing of the sector header in step 130, the sector header including the servo identification field and gray code information is written every three timing marks (1, 4, 7, etc.), and its normal delay is 1 micro seconds and total duration is less than 29 microseconds.

After the sector header is written, the head W is servoed on the amplitude "D" burst to the signal level ratio of Q1 or Q1 _new , step 142 "servo head". The "A" burst written at this location has a normal delay of 30 microseconds and a width of 10 microseconds, step 144 "Write "A"Burst". As before, the write "A" burst is triggered every third timing mark (1, 4, 7, etc.).

After writing the "A" burst, if it is desired to generate servo patterns over more portions of the entire disk surface, query 146 "Write more information?" is answered in the affirmative, and flow returns to step 126 and the process repeats. If not, then in accordance with the principles of the present invention, the process of writing a servo pattern on a disc surface is complete, step 148 "END".

At this point, servo patterns can be generated on any other available disc surface, step 160 "Generate Servo Patterns on Other Surfaces" (FIG. 2). As will be described below, this is done using information from previously written servo patterns.

Referring to FIG. 17, a technique for generating servo patterns on other disc surfaces is described. The head initially writing the widest track is servoed to the signal level of Q1 or Q1 _new on the "B" burst of face W, step 162 "servo a head on the "B"burst". Then the head W reads every three timing marks (i.e., timing marks 1, 4, 7, etc.) on the face W, that is, step 164 "reading the timing mark" and triggering the write operation of the second head on the second face, They can be any head or corresponding face in the disc drive. The second head writes the "C" burst with a normal delay of 40 microseconds, step 166 "Write "C" burst with second head".

Head W then servos on the "D" burst of face W to the signal level ratio of Q1 or Q1 _new , step 168 "servo a head on "D"burst". When the head W is in this radial position, the head W reads every three timing marks (such as 1, 4, 7, etc.) write operation. The second head writes an amplitude "A" burst on the second side with a normal delay of 30 microseconds, step 172 "Write "A" burst with second head".

After writing "A" and "C" bursts, if there are more servo patterns on the surface W, that is, an affirmative answer to query 174 "more information?", then the process returns to step 162, and the process repeats. The above operation assumes that the servo pattern includes "A" and "C" bursts and no "B" and "D" bursts, which are only temporarily used as servo points. The "B" and "D" bursts represent where the data track is located, so the "B" and "D" bursts will be overwritten.

When the servo pattern is generated on an additional side, the sector header information is placed on the second side. The second head servos to the signal level ratio of Q1 or Q1 _new on the "C" burst on the second side, step 176 "Servo the second head on the "C"burst". When servoed in this position, head W is triggered once every three timing marks on face W (such as 1, 4, 7, etc.), with a normal delay of 1 microsecond and a total time of less than 29 microseconds by the second head. The duration is written into a sector header, that is, step 178 "write sector header".

Thereafter, the second head is servoed on the "A" burst on the second side to the signal level ratio of Q1 or Q1 _new , step 180 "servo second head on "A"burst". Once again every three timing marks (such as 1, 4, 7, etc.) on every other surface W trigger a head W and write a sector header, ie step 182 "write sector header". As before, the sector header includes a servo identification field and gray code information and is written with a normal delay of 1 microsecond and a total duration of less than 29 microseconds.

If there is more information to be written, ie the query 184 "more sector information?" is answered in the affirmative, then the flow proceeds to step 176 and the process repeats. If this is not the case, ie all sector information has been written and the process of generating a servo pattern on the other disc surface is complete, step 186 "End". It will be apparent that the above process can be used to generate servo patterns on as many disc surfaces as desired. Referring back to FIG. 2, after the servo pattern has been propagated to the other faces, the process ends, step 190 "END".

The process described above writes the amplitude burst servo pattern on 60 sectors of a disc surface. If a phase-encoded pattern is required, the amplitude burst can be used to provide radial information, while the head writes the phase-encoded pattern using available timing information from the timing marks. Those skilled in the art know that the technique of the present invention can write servo patterns using more than two bursts, two bursts being just one example.

What has been described above is an embodiment for writing a servo pattern on a disc surface. Described below with reference to FIGS. 2 and 18 is another embodiment for writing a servo pattern. Referring to FIG. 2, in this second embodiment, the widest head and the track pitch are determined by the method described in detail below. However, the timing pattern generation is different from the above process, which will be described in detail below with reference to FIG. 18 .

In accordance with the principles of the invention, in this embodiment, the head selected to write the servo pattern is not the one that writes the widest track. As used herein, the selected head is referred to as head 1, but it should be noted that it can be any head in the head drive except the head that writes the widest track. In another embodiment, it may be the widest write header. Referring to FIG. 18, the selected head 1 is used to write magnetic transitions representing a timing pattern on the first track corresponding to the disk surface of the head 1. This plane is called plane 1 here, ie step 200 "write clock track with one head". In one example, clock tracks are written to the disk at a frequency of approximately 2.5 MHz, and one clock track is written at all radial positions on the disk.

After writing the first clock track with the head 1, the actuator 18 is moved a predetermined distance, that is, step 202 "moves the actuator a predetermined distance". In one example, the actuator is moved until the readback signal amplitude is approximately half that of the on-track signal. The actuator is servo-positioned to this half-amplitude position by sampling the rectified head signal. When the actuator is so positioned, head 1 reads the pattern previously written on the first disc side and a second head, called head 2, writes a pattern on the second disc side (side 2) that is identical to the pattern written by the first head. The read pattern is phase-locked so that a new clock track is formed on a different disc surface, ie step 204 "read pattern from head 1 and write pattern with head 2". Similar to head 1, head 2 does not necessarily have to be the second head of the disc drive, but can be any head in the disc drive.

After the timing information is written on the second disc surface, the second head is positioned, that is, step 206 "position head 2". Specifically, the second head switches from write mode to read mode and reads the previously written transition. This signal is converted to an amplitude signal and the actuator is positioned at the amplitude signal level of Q1 or Q1 _new . In this position, the second head reads the clock information on the second surface and writes a second clock track on the first disk surface adjacent to the first clock track by the head 1, that is, step 208 "read the pattern from the head 2 and use the head 1 write mode".

Thereafter, if more clock information is desired to be placed on the disk, that is, the affirmative answer of query 210 "more information?", the process returns to step 202. In one embodiment, it is desirable to place the timing information on the entire disk surface (ie, at all radial positions). Repeat the above process until the clock track is written on the entire disk surface, and the peripheral position of the head can be known at any radial position of the actuator. As long as the readback signals are phase-locked and summed coherently, radial positioning accuracy in the process is not critical.

The technique described above uses two internal recording heads to write to a dedicated clock face. In the example provided, the two recording heads write to different surfaces, but this is not essential. Both heads can write to the same side. One head read pattern and another head write pattern, step by step across the disk surface until a dedicated clock surface is generated.

Referring back to FIG. 2, after the timing information is generated, the servo pattern is written on one disk surface using the head that writes the widest track as described above. Thereafter, the servo pattern is propagated to all disc sides except the one containing the clock information.

In another embodiment, clock information may also be used to write servo patterns on the face in accordance with the principles of the present invention. To accomplish this, the clock information is written between the radial sector information on the second plane (ie, other plane than the original clock plane). If the radial sector on the second face is circumferentially offset relative to the first clock face, then the clock information is available at all theta positions. The clock information on the second plane is used to write the servo pattern on the original clock plane.

Described above are techniques for writing servo patterns without external sensors. Although some preferred embodiments have been illustrated and described in detail herein, it is obvious to those skilled in the art that various changes, additions, substitutions and similar modifications can be made without departing from the essence of the invention, which are all considered to be are included within the scope of the invention as defined in the appended claims.

Claims (69)

1. method that is used for writing servo-pattern on the storage medium that is positioned at pen recorder with internal record head, described storage medium comprises a plurality of radial zones, each radial zone has a plurality of roads, said method comprising the steps of:

On described storage medium, generate a timing mode with described internal record head;

According to being that a radial location value is determined in described zone by the pattern that the internal record head is propagated described at least one zone in described a plurality of radial zones, described radial location value is used for described internal record head is radially located; And

Write a servo pattern with described internal record head on described storage medium, described servo pattern writes on by described timing mode and described radial location and is worth on the determined position.

2. the process of claim 1 wherein that described pen recorder comprises that a plurality of internal record heads and described method further comprise and is used for the step of determining which head of described a plurality of internal record heads writes the widelyest.

3. the method for claim 2, wherein said pen recorder comprises a plurality of storage mediums, each medium in described a plurality of storage medium has at least one stature in the described a plurality of internal record heads that are associated with it, and wherein said which step that writes of definite described a plurality of internal record heads that is used for may further comprise the steps the widelyest:

Write one first transformation with each head in described a plurality of internal record heads;

Write one second transformation with each head in described a plurality of internal record heads, described second transformation is writing from predetermined radial distance place of described first transformation of writing with the described stature in described a plurality of internal record heads;

Change each the head location in described a plurality of internal record heads with described second; And

Read and amplitude signal that is associated with each transformation during described first changes and determine in described a plurality of internal record head according to it which writes the widelyest relatively with the record-header of described location.

4. the method for claim 3, wherein said predetermined radial distance is as upper/lower positions: as described in distance be used for write as described in second change as described in the internal record head as described in the read back waveform of a stature be about half of its maximum amplitude.

5. the method for claim 2, the wherein said determined internal record head that writes is used to generate described timing mode the widelyest.

6. the method for claim 2, the wherein said determined internal record head that writes is used to write described servo pattern the widelyest.

7. the process of claim 1 wherein that described storage medium comprises that N road and the described step that is used for definite radial location value may further comprise the steps:

Write at least one and change on the part in described N road, the described part in described N road is less than described N road;

For a read back waveform is obtained in described at least one transformation on every part of the described part that writes on described N road; And

In described read back waveform, determine described radial location value.

8. the process of claim 1 wherein that described generation step may further comprise the steps:

On first road in a plurality of roads of described storage medium, write first a plurality of transformations; And

On second road in described a plurality of roads of described storage medium, write second batch of a plurality of transformation; Each first of described second batch of a plurality of transformation writes after the corresponding very first time postpones and each second portion of described second batch of a plurality of transformation writes after corresponding second time delay.

9. the method for claim 58, wherein said a plurality of transformations described to comprising that an odd number changes and an even number transformation.

10. the method for claim 1, wherein said pen recorder comprises a plurality of internal record heads and a plurality of recording medium, each medium in described a plurality of recording medium has at least one stature in related described a plurality of internal record heads with it, and wherein said generation step may further comprise the steps:

Write first a plurality of transformations of representing timing mode with first in described a plurality of internal record heads;

With second location in described first and the described a plurality of internal record heads in described a plurality of internal record heads;

Read described first a plurality of transformations and write second batch of a plurality of transformation representing timing mode with first that locatees described in described a plurality of internal record heads with second of the described location in described a plurality of internal record heads;

With described first and the second nose heave new location in described a plurality of internal record heads; And

Read described second batch of a plurality of transformation and write the 3rd batch of a plurality of transformations with described second of reorientating in described a plurality of internal record heads with described first of reorientating in described a plurality of internal record heads.

11. one kind is used for said method comprising the steps of in the method with timing mode of generation on the storage medium in a plurality of roads:

First radial position place on described storage medium writes first a plurality of transformations;

Determine described first a plurality of transformations selected between the time interval;

Determine a departure between each determined time interval and the predetermined normal interval, so that each in described first a plurality of transformations is selected to having a corresponding determined departure; And

Second radial position place on described storage medium writes second batch of a plurality of transformation, each previous transformation that changes in described first a plurality of transformations writes after the corresponding time delay afterwards in described second batch of a plurality of transformation, described corresponding time delay by described normal time at interval and the function of corresponding definite departure determined, thereby the stochastic error that reduces to be associated with the write operation of described first transformation when writing described second batch of a plurality of change is propagated, and reduces will described second batch of a plurality of transformation and stochastic error during described first a plurality of transformations are accordingly aimed at by it.

12. the method for claim 68, an a pair of odd number transformation and the even number of comprising in wherein said first a plurality of transformations changes.

13. the method for claim 68, described first in wherein said second batch of a plurality of transformation represent a plurality of even numbers to change and the wherein said very first time postpone in each delay comprise described predetermined normal interval add with described first a plurality of transformations in the mark of a pair of relevant departure, and in wherein said second batch of a plurality of transformation each described first corresponding in described first a plurality of transformations described to one of.

14. the method for claim 13, the described odd number that wherein will write in described first radial position change as the trigger point and change to write described a plurality of even number.

15. on behalf of each delay in a plurality of odd numbers transformations and wherein said second time delay, the method for claim 12, the described second portion of wherein said second batch of a plurality of transformation comprise a predetermined normal interval.

16. the method for claim 15, the described even number that wherein will write in described first radial position change as the trigger point and change to write described a plurality of odd number.

17. a method that is used for determining the track pitch of a pen recorder that comprises a storage medium, described storage medium has the N road, said method comprising the steps of:

On the multiple tracks in described N road, write a described multiple tracks that changes described N road less than described N road;

Obtain a read back waveform that is associated with the described transformation that on every road of the described multiple tracks in described N road, writes; And

Read back waveform is compared to determine described track pitch.

18. the method for claim 17, the described multiple tracks in wherein said N road comprises Si Tiaodao.

19. the method for claim 17, wherein said write step may further comprise the steps:

(a) locate a record-header of described pen recorder with respect to stop;

(b) write a transformation on the road of record-header in the described multiple tracks in described N road of the described location of use;

(c) on another road in described a plurality of roads in described N road described record-header is repositioned to a precalculated position;

(d) write a transformation on the described record-header of reorientating of use described another road in described a plurality of roads in described N road;

(e) repeating step (c) and (d) writing information all on every road in described a plurality of roads in described N road.

20. the method for claim 19, wherein said described precalculated position of reorientating step (c) comprises such position, is about half of maximum amplitude of described record-header on described position from the described read back waveform of described record-header.

21. the method for claim 19 further may further comprise the steps:

Determine whether described track pitch is correct; And

When described track pitch is incorrect, adjust the value of the described read back waveform of described record-header.

22. comprising, the method for claim 21, wherein said set-up procedure use a predefined formula to determine the step of described adjusted value.

23. the method for claim 22 further comprises and uses the step of described adjusted value with writing information on each bar road in the described multiple tracks in described N road.

24. one kind is used for determining which method that writes in a plurality of record-headers of the pen recorder with a plurality of storage mediums the widelyest, each medium in described a plurality of storage medium has at least one stature of the described a plurality of record-headers that are associated with it, said method comprising the steps of:

Writing first with each head in described a plurality of record-headers changes;

Write second with the stature in described a plurality of record-headers and change, described second changes and is writing from one section preset distance place of first transformation of writing with the described stature in described a plurality of record-headers;

Change each head location in described a plurality of record-headers with described second; And

Read and compare amplitude signal being associated with each transformation during described first changes and determine according to it which head writes in described a plurality of record-header the widelyest with the record-header of described location.

25. the method for claim 24, wherein said positioning step comprise the step that is converted to an amplitude signal with described second.

26. method that is used on a medium of a plurality of storage mediums that are arranged in the pen recorder that comprises a plurality of internal record heads, generating timing mode, each medium of described a plurality of storage mediums has at least one stature in the described a plurality of internal record heads that are associated with it, said method comprising the steps of:

(a) first with described a plurality of internal record heads writes first a plurality of transformations of representing a timing mode;

(b) with second location of described first and described a plurality of internal record heads of described a plurality of internal record heads;

(c) read described first a plurality of transformations and write second batch of a plurality of transformation representing a timing mode with first of the described location of described a plurality of internal record heads with second of the described location of described a plurality of internal record heads;

(d) with described first and the second nose heave new location of described a plurality of internal record heads; And

(e) read described second batch of a plurality of transformation and write the 3rd batch of a plurality of transformations with described second of reorientating of described a plurality of internal record heads with described first of reorientating of described a plurality of internal record heads.

27. the method for claim 26 further is included in and generates before the described timing mode step of execution in step (b)-(e) repeatedly on the whole surface of a described medium of described a plurality of storage mediums.

28. the method for claim 26, the wherein said step of reorientating may further comprise the steps: with described a plurality of internal record heads described first and second move to position like this so that an amplitude signal that is associated with described first a plurality of transformations be about its peaked half.

29. a system that is used for writing servo-pattern on the storage medium that is positioned at a pen recorder with an internal record head, described storage medium comprises that each all has a plurality of radial zones in a plurality of roads, and described system comprises:

Use described internal record head on described storage medium, to generate the device of a timing mode;

According to the pattern of being propagated at least one zone in described a plurality of radial zones by described internal record head is the device that a radial location value is determined in described zone, and described radial location value is used for described internal record head is radially located; And

Write the device of a servo pattern with described internal record head on described storage medium, described servo pattern writes on by described timing mode and described radial location and is worth on the determined position.

30. the system of claim 29, wherein said pen recorder comprises that a plurality of internal record heads and described system further comprise and is used for the device of determining which head of described a plurality of internal record heads writes the widelyest.

31. the system of claim 30, wherein said pen recorder comprises a plurality of storage mediums, each medium of described a plurality of storage mediums has at least one stature in the described a plurality of internal record heads that are associated with it, and wherein said which device that writes of definite described a plurality of internal record heads that is used for further comprises the widelyest:

Write first device that changes with each of described a plurality of internal record heads;

Stature with described a plurality of internal record heads writes second device that changes, and described second changes the predetermined radial distance place of described first transformation that writes on from writing with a described stature of described a plurality of internal record heads;

With described second device that changes each location of described a plurality of internal record heads; And

Read and compare amplitude signal being associated with each transformation of described first transformation and determine the device which head writes in described a plurality of internal record head the widelyest with the record-header of described location according to it.

32. the system of claim 31, wherein said predetermined radial distance is such position, the read back waveform that wherein is used to write a described stature of the described second described internal record head that changes be about its peaked half.

33. the system of claim 30, the wherein said internal record head that is confirmed as writing is used to generate described timing mode the widelyest.

34. the system of claim 30, the wherein said internal record head that is confirmed as writing is used to write described servo pattern the widelyest.

35. the system of claim 29, wherein said storage medium comprises that N road and the described device that is used for definite radial location comprise:

Be used for writing on the part in described N road the device of at least one transformation, the described part in described N road is less than described N road;

Be used to obtain the device of the read back waveform of described at least one transformation on each the described part that writes on described N road; And

Be used for determining the device of described radial location value according to described read back waveform.

36. the system of claim 29, the wherein said device that is used to generate comprises:

Be used on first road in a plurality of roads of described memory storage, writing the device of first a plurality of transformations; And

Be used for writing on second road in described a plurality of roads of described memory storage the device of second batch of a plurality of transformation, described second writes instructions and transfer that each first that becomes writes and each second portion of described second batch of a plurality of transformation writes after corresponding second time delay after a corresponding very first time postpones.

37. the system of claim 64, wherein said a plurality of transformations described to comprising that odd number changes and an even number transformation.

38. the system of claim 29, wherein said pen recorder comprises a plurality of internal record heads and a plurality of recording medium, each medium of described a plurality of recording mediums has at least one stature of the described a plurality of internal record heads that are associated with it, and the wherein said device that is used to generate further comprises:

First device that writes first a plurality of transformations of representing a timing mode with described a plurality of internal record heads;

Be used for device with second location of described first and described a plurality of internal record heads of described a plurality of internal record heads;

Read described first a plurality of transformations and with second device that writes second batch of a plurality of transformation representing a timing mode of the described location of described a plurality of internal record heads with first of the described location of described a plurality of internal record heads;

Be used for device with described first and the second nose heave new location of described a plurality of internal record heads; And

Read described second batch of a plurality of transformation and write the device of the 3rd batch of a plurality of transformations with described first of reorientating of described a plurality of internal record heads with described second of reorientating of described a plurality of internal record heads.

39. one kind is used in the system with generation timing mode on the storage medium in a plurality of roads, described system comprises:

Be used for the device that first radial position place on described storage medium writes first a plurality of transformations;

Be used for determining described first a plurality of transformations selected between the device in the time interval;

Be used for determining that each determines that departure between the time interval and the predetermined normal interval is so that every pair of described first a plurality of transformations is selected to having a device of definite departure accordingly; And

Be used for the device that second radial position place on described storage medium writes second batch of a plurality of transformation, each transformation writes after the corresponding time delay of the previous transformation of described first a plurality of transformations in described second batch of a plurality of transformation, described corresponding time delay is determined by the function of described normal time interval and corresponding determined departure, thereby the stochastic error that reduces to be associated with writing of described first a plurality of transformations when writing described second batch of a plurality of change is propagated, and reduces will described second batch of a plurality of transformation and stochastic error during described first a plurality of transformations are accordingly aimed at by it.

40. the system of claim 69, an a pair of odd number transformation and the even number of comprising in wherein said first a plurality of transformations changes.

41. the system of claim 69, on behalf of each delay that a plurality of even numbers change and the wherein said very first time postpones, the described first of wherein said second batch of a plurality of transformation comprise that described predetermined normal interval adds the mark of a departure relevant with a pair of transformation of described first a plurality of transformations, and each described first of wherein said second batch of a plurality of transformation corresponding to described first a plurality of transformations described to one of.

42. the system of claim 41 wherein will change as the trigger point writing described a plurality of even number transformation at the described odd number that described first radial position place writes.

43. the system of claim 40, on behalf of a plurality of odd numbers, the described second portion of wherein said second batch of a plurality of transformation change and each delay of wherein said second time delay comprises a predetermined normal interval.

44. the system of claim 43 wherein will change as the trigger point writing described a plurality of odd number transformation at the described even number that described first radial position place writes.

45. the system of the track pitch of a pen recorder that is used to determine to comprise storage medium, described memory storage has the N road, and described system comprises:

Be used for writing on the multiple tracks in described N road the device of transformation, the described multiple tracks in described N road is less than described N road;

Be used to obtain the device of the read back waveform that is associated with the described transformation that on every road of the described multiple tracks in described N road, writes; And

Be used for more described read back waveform to determine the device of described track pitch.

46. the system of claim 45, the described multiple tracks in wherein said N road comprises four roads.

47. the system of claim 45, the wherein said device that is used to write comprises:

Be used for a relative stop and locate the device of a record-header of described pen recorder;

Use the device that writes transformation on the road of record-header in the described multiple tracks in described N road of described location;

Be used for described record-header is repositioned to the device in a precalculated position on another road of described multiple tracks in described N road; And

Use described record-header of reorientating on described another road of the described multiple tracks in described N road, to write the device of a transformation.

48. the system of claim 47, the described precalculated position of the wherein said device that is used to reorientate comprises such position, wherein is about half of maximum amplitude of described record-header from the described read back waveform of described record-header.

49. the system of claim 47 further comprises:

Be used for determining the device that described track pitch is whether correct; And

When described track pitch is incorrect, be used to adjust the device of the described read back waveform value of described record-header.

50. the system of claim 49, the wherein said device that is used to adjust comprises that predefined formula of use is to determine the device of described adjusted value.

51. the system of claim 50 further comprises the device that uses described adjusted value writing information on every road of the described multiple tracks in described N road.

52. one kind is used for determining which system that writes in a plurality of record-headers of the pen recorder with a plurality of storage mediums the widelyest, each medium of described a plurality of storage mediums has at least one stature in the described a plurality of record-headers that are associated with it, and described system comprises:

Each that use described a plurality of record-headers writes first device that changes;

Use a stature of described a plurality of record-headers to write second device that changes, described second changes the one section preset distance of first transformation that is write at the described stature from the described a plurality of record-headers of use writes;

Use described second device that changes each location of described a plurality of record-headers; And

Use the record-header of described location to read and compare one determine the device which head writes in described a plurality of record-header the widelyest with amplitude signal being associated of each transformation during described first changes and according to it.

53. the system of claim 52, the wherein said device that is used to locate comprises and is used for the device that is converted to an amplitude signal with described second.

54. system that is used on a medium of a plurality of storage mediums that are positioned at the pen recorder that comprises a plurality of internal record heads, generating a timing mode, each medium of described a plurality of storage mediums has at least one stature in the described a plurality of internal record heads that are associated with it, and described system comprises:

Use first device that writes first a plurality of transformations of representing a timing mode of described a plurality of internal record heads;

Be used for device with second location of described first and described a plurality of internal record heads of described a plurality of internal record heads;

Use first second device that writes second batch of a plurality of transformation representing a timing mode that reads described first a plurality of transformations and use the described location of described a plurality of internal record heads of the described location of described a plurality of internal record heads;

Be used for device with described first and the second nose heave new location of described a plurality of internal record heads; And

Use described second of reorientating of described a plurality of internal record heads to read described second batch of a plurality of transformation and use described first of reorientating of described a plurality of internal record heads to write the device of the 3rd batch of a plurality of transformations.

55. the system of claim 54, the wherein said device that is used to reorientate comprises described first and second device that moves to a position that is used for described a plurality of internal record heads, an amplitude signal that in described position, is associated with described first a plurality of transformations be about its peaked half.

56. a pen recorder comprises:

A storage medium that is positioned at described pen recorder, described storage medium comprise that each has a plurality of radial zones in a plurality of roads;

An internal record head that is positioned at described pen recorder, be used for following operation: on described storage medium, generate a timing mode, generate a pattern and on described storage medium, write a servo pattern to determine the radial location value that described internal record head is radially located, to reach; And

Being used for according to the pattern of being propagated by described internal record head in the described zone is the device of at least one definite radial location value in zone of described a plurality of radial zones, and described radial location value is used for described internal record head is radially located.

57. the process of claim 1 wherein and be used for determining that the step of radial location value is included as the step that each radial zone is determined a radial location value.

58. the method for claim 8 further may further comprise the steps:

Determine a time interval between every pair of described first a plurality of transformations; And

Determine the departure between each time interval of determining and the predetermined normal interval, so that every pair of described first a plurality of transformations has a corresponding definite departure.

59. the method for claim 58, wherein according to described predetermined normal interval with postpone with each that determine that the described very first time postpones with the function of a pair of relevant departure of described first a plurality of transformations, and every part of the described first of wherein said second batch of a plurality of transformation corresponding to described first a plurality of transformations described to one of.

60. the method for claim 58, each delay that wherein said very first time postpones comprises that described predetermined normal interval adds the mark with a pair of relevant departure of described first a plurality of transformations, and each part of the described first of wherein said second batch of a plurality of transformation corresponding to described first a plurality of transformations described to one of.

61. the method for claim 68, wherein according to described predetermined normal interval with postpone with each that determine that the described very first time postpones with the function of a pair of relevant departure of described first a plurality of transformations, and each part of the described first of wherein said second batch of a plurality of transformation is corresponding to one of described centering of described first a plurality of transformations.

62. the method for claim 11 further comprises the repetition of step what follows: determine the step in a time interval, determine that the step of a departure reaches the step that writes second batch of a plurality of transformation for every road in described a plurality of roads.

63. the system of claim 29, the wherein said device that is used for definite radial location value comprises the device that is used to each radial zone to determine a radial location value.

64. the system of claim 36 further comprises:

Be used for determining the device in a time interval between every pair of described first a plurality of transformations; And

Be used for determining that a departure between each determined time interval and the predetermined normal interval is so that every pair of device that all has a corresponding determined departure of described first a plurality of transformations.

65. the system of claim 64, wherein according to described predetermined normal interval with postpone with each that determine that the described very first time postpones with the function of a pair of relevant departure of described first a plurality of transformations, and each part of the described first of wherein said second batch of a plurality of transformation corresponding to described first a plurality of transformations described to one of.

66. the system of claim 64, each delay that wherein said very first time postpones comprises that described predetermined normal interval adds the mark with a pair of relevant departure of described first a plurality of transformations, and each part of the described first of wherein said second batch of a plurality of transformation corresponding to described first a plurality of transformations described to one of.

67. the system of claim 69, wherein according to described predetermined normal interval with postpone with each that determine that the described very first time postpones with the function of a pair of relevant departure of described first a plurality of transformations, and each part of the described first of wherein said second batch of a plurality of transformation corresponding to described first a plurality of transformations described to one of.

68. the method for claim 11, wherein said second batch of a plurality of transformation are included in the first of the transformation that corresponding very first time writes after postponing and the second portion of the transformation that writes after corresponding second time delay.

69. the system of claim 39, wherein said second batch of a plurality of transformation are included in the first of the transformation that corresponding very first time writes after postponing and the second portion of the transformation that writes after corresponding second time delay.

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