JPS58501879A - Track identification code recording method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] How to record tiger/ri identification code The present invention relates to a method for recording a unit distance truck identification code, and further relates to a method for recording a unit distance truck identification code. Specifically, the unit distance characteristic of the code is retained, and the unit distance characteristic is the identification code. A method for recording information on a magnetic disk that a computer can call magnetic disk storage to obtain relatively inexpensive large-capacity memory, i.e., storage devices. Storage devices are widely used. A typical disk storage device uses a suitable magnetic material. several disks coated and arranged to rotate on a common spindle and held in pairs on an elongated support for insertion between adjacent discs. n sets of transducer heads. The heads of each pair of heads are in opposite directions. and contact opposing surfaces of adjacent discs. The support structure is is coupled to the position setting motor. Its positioning motor uses a magnetic field to perform linear motion is mounted on the disk to move the head radially over the surface of the disk. by pointing the head against any annular track on the disk surface. It usually includes a coil that allows it to be positioned above. Normal operation In the , the position setting motor responds to control signals from the computer and sends data signals. A set of concentric recording tracks on the disk, one preselected track on the disc. or a preselected one of a set of concentric recording tracks. To retrieve the data signal from the book track, send the card to the transducer. Position radially.

In such devices, the transducer head is positioned over the desired recording track. It is desirable to record data on a disk so that it can be placed on a disk.

Therefore, several tigers for driving the magnetic disk 1.

A tracking device has been developed. Most commonly, one disk surface and one head track following sir? dedicated to recording location information for use by the device. It is used for In these devices, position information is connected around the disk. It will be recorded continuously. A typical technology for recording location information is Santana (San U.S. Pat. No. 3,534,344 to Tana and Muel U.S. Pat. No. 3,691,543 to L. those In two patents, clock pulses are time gated from the recorded clock pulses. Position information is extracted from one pulse amplitude. Continuous designed for In the device, those pulses are repeated continuously around the disk and the comparator Position information is obtained at the output terminal of.

In such continuous equipment, no matter how fast the head carriage moves, , each track crossing can be detected by a track following circuit. For this reason, the truck This will cause the transducer head to reach the desired track until the track difference is equal to zero. Just by decreasing the difference counter of Tora, ri, which means that you have reached Tora, identification information can be extracted.

For various practical reasons, it is desirable to track data to the same surface on which it is recorded. recording track position information and using dedicated surfaces and heads for track position information. It is desirable to eliminate the need. One reason is that the target tiger has a straight head. Because it is moved manually, the center alignment of the disc is necessary for data exchange and temperature changes. It is possible to adjust the deviation. Another reason is that the head in the disk drive physical alignment requires alignment of many heads on many surfaces. It is not difficult if you have to do so. As a result, on-site adjustments are common becomes unnecessary. Another obvious reason is that the entire surface of the disk is dedicated to location information. There is no need to use it for any purpose.

As a result, recently developed devices contain embedded server information (i.e., header information). is used to record data for use by de-tracking and surfing equipment. (identification information pre-recorded on the same surface as the original). The embedded sensor is In the most practical form of storage, each track is divided into sections, with each data Track identification and precise location information are recorded at the beginning of the data section. That information is Used to read and write data. . An example of a conventional embedded sensor device is given by Hertrieh. Granted U.S. Patent No. 4,208,679, Van H@rk No. 4,163,265, issued to et al., issued to Card. U.S. Pat. No. 4,149,201, granted to Kimura. No. 3,812,533, U.S. Patent No. 31 to Sipple. No. 85972 and British Patent Application No. 85972 to Droux. No. 2017364.

In magnetic disk drives that use embedded serve technology, You must know about what is positioned on top of the truck. This cornerstone Crossings of track boundaries are typically counted to meet the request. Consecutive record sir? In the device, information can be obtained continuously, so the head moves at high speed, It's not a problem to count boundaries while

However, as here, track boundary information can only be obtained intermittently. Embedded sir TI? The device cannot jump track boundaries.

Therefore, it becomes necessary to identify tigers and ri. This identification applies to all We have gone to the extreme of recording absolute track addresses for trucks and trucks. It's possible.

A more practical technique is to record the band being flipped. In that case L Tracks are identified within bands, i.e. 16 tracks per band. The tracks included in one band are numbered from 0 to 15. Ru. In this case, only 4 bits of data are needed for track identification. be.

When recording this type of data, a unit distance commonly referred to as a Gray code is used. Preferably, a separate cord is used. Those codes contain only one bit of code. The tracks were also developed to change when the boundaries between the tracks change. It is. Using the Gray code, the ambiguity lies in the position of the head of the track. Limited to uncertainty.

The remaining questions concern the combination of unit distance codes and magnetically recorded information. It is something. Although conventional magnetic recording codes such as NRZ or MFM are used , there is an ambiguity about the track boundaries, which causes Since the above uncertainty arises, the unit distance feature that the Gray code is based on is destroyed. It will be done. This is best seen in Figures 1.2 and 3.4.

Specifically, FIG. 1 shows each of four consecutive tracks on the surface of a magnetic disk. Indicates the data you want to record at the beginning of the section. For purposes of discussion here, those Number the tracks 2.1, 0.15. Figure 1 shows four consecutive bits. cells and their bis.

rlJ and roj recorded in the cell are also shown. Tora, the identification code is the unit distance. chord, i.e. only one bit of the chord when the boundary between tracks is varied. It can be seen from this figure that the cut changes.

Figure 2 shows that for NR2 encoding, the actual Show transitions first. “1” is indicated by transition, while “0” is indicated by transition. It can be seen that this is shown by the shift. Tora, Ri 2 and 1 are indicated by A, B, and C. The three possible positions of the transducer head are superimposed. at position A In this case, the transducer head is precisely aligned with track 2. I understand that. When in position C, the transducer head is on track 1. When correctly positioned and in position B, the transducer head is on track. It is placed between 2 and 1.

This convention will also be used in subsequent figures.

Figure 2 shows the signals 21.22.2 obtained from the heads at positions A, B, and C, respectively. 3 is also shown. When in position A, the magnetic transitions at 24 and 25 are at 26.27. It can be seen that the magnetic transition at 28 is detected at 29, respectively. death However, when the transducer is in position BIC, the transition at 24 is Naturally, it is detected at 30, but the transitions at 25 and 28 are canceled.

Therefore, the track locator decodes position 0010. This position is actually It clearly has no relation to the track position of .

FIG. 3 shows the Gray code binary gutter of FIG. 1 recorded for FM encoding. It shows you how to do it. In FM encoding, to indicate the presence of "1", There are black and white transitions at each cell boundary, and transitions in the middle of the cell. track 2 and 1 with head positions A and B.

C is superimposed. Figure 3 also shows the transducer head at position tAts+c. At the same time, signals 31, 32, and 33 are shown which are respectively changed from the to the do.

It is also known that ambiguity results in cells with put-bit changes. Karu. When in position A, the transitions at 34 and 35 are at 36.37 respectively. is detected and at position C, the transitions at 38 and 39 are at 40.41. Nine times each are detected. However, when at position B, the transition at 34.38 cancels the transition at 35.39, so the clock transition at the cell boundary It also cancels transitions in intermediate cells. This is an illegal FM signal that cannot be decoded by a decoding circuit. This is the number.

Figure 4 shows how the binary data of Figure 1 is recorded for MFMFM encoding. 7 In this MFMFM encoding, the clock transition in the middle cell is "1" There is a black transition at the boundary of each cell except near "1". truck Possible head position A for tracks 2 and 1.

B and C are superimposed. Also shown in FIG. 4 are signals 51°52.53.

Those signals 51, 52 and 53 are respectively when the head is in positions A, B and C. can get. When in position A, the transition at 54 is detected at 55 and the position When at C, the transition at 56 is detected at 57. However, in position B Sometimes transitions are detected at 54 and 56 as shown at 58.59. However, this is an illegal signal that cannot be decoded by the decoding circuit.

A prior art solution to this problem is shown in the aforementioned U.S. Pat. No. 3,812,533. ing. In this method, two time pulses are added at a certain track boundary. Then, the space between two adjacent time windows becomes blurred, making one track indeterminate. so that each track indicates the track identification by the time index of one pulse. Track identification is performed by that one reference signal above. But in this way has to divide the various tracks into many windows, so in order to make the decoding more efficient, requires a large number of circuits.

Summary of the invention In accordance with the present invention, a simple method solving the problem of Sell et al. in a previously unknown manner. A method for recording a distance track identification code on a magnetic disk is provided. this record The technology allows the decoding circuit to know exactly between which tracks the head is present. , which completely eliminates ambiguity about track boundaries. This is necessary easily and efficiently in a way that greatly simplifies the required decoding circuitry. It will be done.

In summary, in a disc with bilateral surfaces, at least one said surface is coated with a magnetic material, and the disk is used for recording data on the surface. and a magnetic transducer positioned to retrieve data from said surface. It is designed to be mounted on a spindle for rotation against a plurality of concentric rings. shaped tracks are formed on the surface of the disk, each track being divided into a plurality of parts. Identification data is recorded in advance on each part to identify each part. n2, their pre-recorded identification data includes a track identification code; The tiger identification code is a unit distance code. The disk has surfaces on both sides. In each bit cell, the code includes a first unidirectional clock of fixed time. and a second unidirectional transition of variable time in each cell; The time of the second transition for the data bit determines whether the data bit is 1 or 0. A method is disclosed.

Therefore, an object of the present invention is to record a unit distance code on a magnetic disk. The goal is to solve all related problems. The characteristics of the present invention are the results of magnetic recording technology and Single track only claims without adding further uncertainty. Track identification, unit distance code using % interval code sound to hold the distance The goal is to solve these problems by recording them. The benefits achieved are The unit distance feature of the recorded code is preserved. Another benefit is claimed The ambiguity of one track is maintained. Yet another advantage is the extra This means that there is no longer any uncertainty. Yet another advantage is that illegal code It's gone.

Further objects, features, attendant advantages, etc. of the present invention are set forth below in connection with the accompanying drawings. It will not be obvious to one skilled in the art from reading the description of the preferred embodiment described. There will be. In the accompanying drawings, the same numbers in some drawings refer to the same parts. It refers to

Brief description of the drawing Figure 1 is a diagram of secondary data recorded on the disk surface, Figure 2 is the NRZ encoding method. How to record the data shown in Figure 1 onto a disk using transducer heads located above positions A, B, and C). Figure 3 is a diagram showing the data shown in Figure 1 using the FM encoding method. How to record on a disc and how to position the disc above tA, B, and c. A diagram showing the signals obtained from the transducer head in FIG. As soon as the data shown in Figure 1 is recorded on a disc using the FM encoding method, To the transfer data center located above the screen positions [A, B, C] A diagram illustrating the signals obtained from the head, FIG. 5, is shown in FIG. How to record the data and its location A and B on the disk.

Diagram showing the signal obtained from the transducer head positioned above C It is.

First, FIG. 5 shows a preferred embodiment of encoding that preserves the characteristics of unit code distance. See. To preserve the value of the unit distance code, the transitions recorded are one traffic only one transition or group of transitions from one track to the next track must be changed . It is also desirable to minimize the number of transitions per bit in order to facilitate decoding. Yes. From this consideration, we can determine the position that determines whether a bit is 1 or O. Guided by code containing forced or lock transitions plus forced data transitions . In accordance with a preferred embodiment of the present invention, a forced lock transition is applied to each bit cell. fixed-time unidirectional clock transitions with data transitions also occurring at each bit cell. This is a variable-time, one-way clock transition. Time of second transition relative to first transition determines whether the data bit is a 1 or a 0. The embodiment shown is Akira It is a code.

More specifically, referring to FIG. 5, the binary data shown in FIG. You can see how it is recorded in the file 2, 1.0.15. Each bit° cell starts with a transition. So, you can see that it ends with a transition, and that the transition is always in the same direction. death As a reminder, all tracks have constant time transitions within each bit cell, shown at 61. have, have. Additionally, bit cells have unidirectional transitions. This transition is 1 bit cell after clock transition for or clock transition for O This is the disaster of bit cells after . What this means is that the trucks at positions A, B, and C Comparing the signals 62, 63, and 64 obtained by Nancedesa, Dor, et al. Recognize.

More specifically, in any position A, B or C, the head is They receive exactly the same signals, except for the bit cells where there is a possible ambiguity.

In that cell, i.e. the third cell, the head at position A causes 61A, 65 ．． The transitions at 61B are detected at 966.67.68, respectively, and the transitions at position C are Due to Aruto and Do, the transitions at 61C, 69, and 61D become 70, 71., respectively. Detected at 72.

With the head in position B, the signals detected at 66 and 70 are detected at 73. As shown, the signals added and detected at 68.72 are: As shown at 74, they are added together.

There is therefore some cancellation between the signals detected at 67 and 71. There will be obscurity, so the decoding circuit can decode a 1 or a 0. Therefore, The decoding circuit easily decodes 0071. This means that the transducer This can clearly be interpreted as indicating that is between tracks 1 and 2. Therefore, Not only is decoding allowed, but decoding where the transducer head is Any ambiguity can actually be exploited to accurately direct the circuit.

% in other recording environments such as low-cost digital cassette recorders. The code has been used for some time. Therefore, to decode signals 62, 63, and 64, Such decoding circuits are well known to those skilled in the art. However, the magnetic disk decoder By combining this type of encoding with unit distance codes, other encoding techniques It provides benefits that cannot be obtained with other techniques.

Having described the preferred practical embodiments of the invention made in accordance therewith, It will be apparent to those skilled in the art that various improvements and changes can be made without departing from the spirit of the invention. It should be obvious. Therefore, the invention is limited by the specific embodiments described. You understand that you are limited only by the scope of the claims appended hereto. Should.

Hand V Gon IIfftFF! words (method) %formula%) 1.Display of the incident PCT,,,’US82/’003862 Title of invention Track identification code recording method 3. Person who makes corrections Relationship with matter A9 Special feature '1 applicant DMNY, Systems 1, Corporation 4, Agent (104) 6th floor, Ginza Daisaku Hill, 2-11-2, Ginza, Chuo-ku, Tokyo Phone 03- 545-3508 (Representative) July 28, 1982 (Shipping date: August 2, 1982) 6. Subject of correction Drawing translation Wanfu 1's Inner Song Dynasty csi's @rokuf/l can be counterfeit ζ international search report 1, ( [

Claims (1)

[Claims] L: A disk with surfaces on both sides, at least one of which has a magnetic material. is coated t1 for recording data on the surface and for recording data on the surface. Rotating for a magnetic transducer positioned to retrieve data from a surface. It is designed to be mounted on a spindle for rotation, and includes a plurality of concentric rings, a track is formed on the surface of the disk, and each track is divided into a plurality of parts. company identification data is recorded in advance on each part to identify each part, Their pre-recorded identification data includes a truck identification code, and , the identification code is a unit distance code, in a disc with surfaces on both sides. , the code includes a first unidirectional clock transition of fixed time within each bit cell; a second unidirectional transition of variable time within each bit cell; The time of said second transition to determines whether the data bit is 1 or 0. Improvement. 2. In the disc according to claim 1, the second transition is a data ・Up to one third of the width of each bit cell, depending on whether the bit is 1 or 0. or two-thirds of the distance from said first transition. 3. In the disc according to claim 1 or 2, the first clock , the transition demarcates each bit cell, an improvement.