JP4105297B2 - Magnetic recording apparatus and magnetic recording signal generating apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic recording device such as a magnetic disk device and a magnetic tape device, and a magnetic recording signal generation device.
[0002]
Magnetic recording in a magnetic disk device or the like simultaneously erases previous data and records new data by overwriting new data over previously recorded data (previous history data) (overwrite recording method).
[0003]
FIG. 13 is an explanatory diagram of a conventional recording method.
In FIG.
Reference numeral 111 denotes a head which records data on a magnetic recording medium.
[0004]
A recording current generation circuit 112 generates a recording current that flows through the head 111.
Reference numeral 113 denotes an oscillation circuit.
[0005]
Reference numeral 114 denotes a recording data generation circuit.
Reference numerals 121 and 122 denote magnetic recording media for recording data such as floppy disks and magnetic tapes.
[0006]
FIG. 13A shows the recording state A in the previous history state. The recording state is indicated by the direction of the arrow, and the direction of the magnetic domain is indicated. FIG. 13 shows an overwrite-type recording method. For example, when data 1 is written, the direction of the magnetic domain is reversed, and data 0 does not cause a change in the magnetic domain.
[0007]
FIG. 13B shows the recording current. When 1 appears in the data value (t1, t2, t3, t4, t5, t6), the direction of the recording current is reversed and the direction of the recorded magnetic domain is reversed. When the data value is 0, the magnetic domain is not inverted (NRZI recording).
[0008]
FIG. 13C shows a recording state based on the recording current of FIG. Δx represents the delay time of the magnetic domain inversion with respect to the signal application timing when the magnetic domain is inverted in a direction different from the previous history state.
[0009]
The recording state B is a recording state when data is recorded with the recording current of FIG. When the magnetic domain is reversed with the recording current corresponding to the data value 1, when the direction of the reversed magnetic domain is opposite to the direction of the previous magnetic domain, the magnetic domain is reversed at a position delayed by Δx from the time of application of the recording current. Are recorded (t1, t3, t4, t6). However, when the magnetic domain is reversed by the recording current, the recording position is not delayed when the direction of the reversed magnetic domain is the same as the direction of the previous magnetic domain (t2, t5).
[0010]
[Problems to be solved by the invention]
As the recording density increases, the occurrence of magnetic domain inversion shift caused by the influence of the previous history data becomes a problem as described above. Regarding this problem, for example, the document “Overwrite in Thin Media Measured by the Method of Pseudorandom Sequences”. IEEE Transaction on Magnetics. Vol. 24, no. 6, November 1988. Etc. are discussed.
[0011]
An object of the present invention is to provide a magnetic recording apparatus and a magnetic recording signal generation apparatus in which write data is correctly recorded at a position where the write data is to be recorded.
[0012]
[Means for Solving the Problems]
The present invention relates to a magnetic recording apparatus for generating a magnetic recording signal for recording an electric signal on a magnetic recording medium, comprising a recording head for recording data on the recording medium, and a recording signal generating apparatus for generating a recording signal. The generating device includes an erasing signal means for generating a signal for erasing already recorded data by magnetizing the magnetic recording medium in a certain direction before recording the data, and a magnetic domain recorded by erasing when recording the data. And a recording signal generating means for generating a magnetic recording signal for applying a recording current timing applied to the recording means earlier than a time at which a magnetic domain should be formed when magnetizing in a direction opposite to the direction of The data was recorded after aligning the magnetization direction in a certain direction.
[0013]
FIG. 1 is a diagram showing a basic configuration of the present invention.
In FIG.
Reference numeral 1 denotes a magnetic recording apparatus which records data on a magnetic recording medium (not shown) by the recording means 13.
[0014]
Reference numeral 2 denotes a magnetic recording signal generating device that generates a recording signal for recording data on the magnetic recording medium and an erasing signal for erasing the previous record of the magnetic recording medium.
[0015]
Reference numeral 3 denotes an erasing signal generating means for generating an erasing signal for erasing the previous history of the magnetic recording medium.
Reference numeral 5 denotes a recording signal generating means for inputting write data and generating a recording signal having an appropriate timing so that the data is correctly recorded at a position to be recorded by the recording means 13.
[0016]
Reference numeral 7 denotes recording timing adjusting means for adjusting a recording signal so that a shift from a recording position of the magnetic recording medium does not occur.
A control means 9 controls the generation of the recording signal and the erasing signal.
[0017]
FIG. 2 is a diagram for explaining the operation of the basic configuration of the present invention.
In FIG. 2, reference numeral 21 denotes a magnetic recording medium.
FIG. 2A shows a recording state A, which represents a storage state of previous history data.
[0018]
FIG. 2B shows a DC erasing current, which indicates that the current of −I is passed through the recording means to erase the previous history of the magnetic recording medium 21.
FIG. 2C shows a recording state after DC erasure.
[0019]
FIG. 2 (d) shows a recording current before timing adjustment, and times t1, t2, t3, t4, t5, and t6 are recording currents, and are in a state before adjusting the timing of flowing through the magnetic recording means.
[0020]
FIG. 2 (e) shows the recording current flowing through the magnetic recording means after timing adjustment, and the times t1 ′, t3 ′, and t5 ′ are signals that are earlier by Δx than the times t1, t3, and t5 in FIG. 3 (c). Is standing up.
[0021]
FIG. 2F shows a recording state D, which shows a recording state recorded on the magnetic recording medium 21 when recording is performed with the recording current of FIG.
The basic configuration of the present invention shown in FIG. 1 will be described with reference to FIG.
[0022]
The erasure signal generation means 3 generates the DC erasure current of FIG. 2 (b) and sends it to the recording means 13 to erase the previous history of FIG. 2 (a), and the magnetic recording medium 21 is in the recording state of FIG. C. For example, in the case of FIG. 2, DC erasing is performed by passing a current in a fixed direction (positive or negative) through the erasing means (head). In the example of FIG. 2, DC erasure (hereinafter referred to as demagnetization or erasure) is erased with a negative current value -I. Write data is input to the recording signal generating means 5. The magnetic recording signal generating means 5 generates a recording current after timing adjustment based on the write data. In this signal, if the recording current before timing adjustment is as shown in FIG. 2D, the recording timing adjusting means 7 generates the inversion of the magnetic domain in the direction opposite to the direction of the magnetic domain in the recording state C. In this case, the application timing of the recording current for writing is advanced by Δx (see t1 ′, t3 ′, and t5 ′ in FIG. 2E). In the case of the example in FIG. 2, the shift is performed by Δx only when the recording current is reversed from negative to positive. When the magnetic domain inversion is generated in the same direction as the magnetic domain in the recording state C, the tamming for applying the recording current is not changed. By applying this recording current to the recording means, as shown in FIG. 2F, it is possible to obtain a recording state D in which the written data is written at the correct position.
[0023]
As described above, according to the present invention, the influence of the previous history data when the magnetization is reversed in the direction opposite to the previous history state can be eliminated, and the data can be recorded at the correct position of the magnetic recording medium.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows the first embodiment of the present invention.
In FIG.
Reference numeral 2 denotes a magnetic recording signal generator.
[0025]
Reference numeral 23 denotes a head.
31 is an AND circuit.
32 is a D flip-flop circuit.
[0026]
A delay circuit 33 delays the signal by Δx.
Reference numeral 34 denotes an OR circuit.
B, c, d, e, f, and g in FIG. 3 correspond to signals of the same sign with parentheses in the time chart of FIG.
[0027]
FIG. 4 is a time chart of the operation of the configuration of FIG.
FIG. 4A shows write data.
FIG. 4B shows an NRZI signal generated based on the write data (a).
[0028]
FIG. 4C shows a synchronous clock pulse signal.
FIG. 4D is a signal indicating the timing of the write data 1 generated based on the NRZI signal in FIG. 4B and the clock pulse in FIG.
[0029]
FIG. 4E is a signal corresponding to the rising edge of the odd-numbered pulse signal in the pulse train of FIG.
FIG. 4F is a signal obtained by delaying the signal of FIG. 4E by Δx.
[0030]
FIG. 4D shows a signal obtained by ORing the signals shown in FIGS. 4E and 4F.
FIG. 4H shows a demagnetized magnetic recording medium.
[0031]
FIG. 4 (i) shows a signal applied to the head, which is the same as the signal shown in FIG. 4 (g).
FIG. 4J shows the state recorded on the recording medium.
[0032]
The operation of the configuration of FIG. 3 will be described with reference to FIG.
In FIG. 4, the signals (b) and (c) of FIG.
As a result, the AND circuit 31 outputs the signal (d) in FIG. In the signal of FIG. 4D, the pulse corresponds to 1 of the write data. When recording data on the head 23, a set signal for writing is applied to the reset terminal of the flip-flop as an erase / write control signal. Then, by inputting the signal of FIG. 4D to the clock signal input terminal of the flip-flop 32, the signal of FIG. 4E is obtained as the output of the flip-flop circuit 32. By inputting the signal of FIG. 4E to the delay circuit 33, a signal (f) obtained by delaying the signal of FIG. 4E by Δx is obtained. By passing the signal of FIG. 4 (e) and the signal of FIG. 4 (f) through the OR circuit 34, the signal of FIG. 4 (g) is obtained. This signal is input to the recording circuit 36 and data is recorded on the magnetic recording medium by the head 23.
[0033]
This signal (g) (same as FIG. 4 (i)) is a signal for reversing the direction of magnetization corresponding to the data value of 1 in the magnetic recording medium, but in the direction opposite to the direction of the magnetic domain being erased. Is applied earlier by Δx. Therefore, since it is applied to the magnetic recording medium with a delay of Δx time, the data is recorded on the magnetic recording medium at a position where the data should be correctly recorded (FIGS. 4H, 4I, and 4J). reference).
[0034]
In the configuration of FIG. 3, when erasing the magnetic recording medium, a reset signal is applied for erasing as an erase / write control signal. At this time, a positive or negative DC signal for erasing the magnetic recording medium is output from the flip-flop 32, and the magnetic recording medium is erased (see FIG. 4H).
[0035]
In the configuration of FIG. 3, by appropriately setting the direction of the current for erasing by resetting and inputting the signals of FIGS. 4B and 4C, data can be recorded on the magnetic recording medium at the correct timing. .
[0036]
FIG. 5 is an explanatory diagram of Embodiment 2 of the present invention.
When recording on a magnetic recording medium, when there is a magnetization reversal one bit before (when a writing bit continues) or two bits before, the subsequent magnetization reversal is accelerated by that effect (the position where the recording is Shift). In order to eliminate this influence, the writing timing is delayed in writing such bits.
[0037]
FIG. 5A shows a recording state A, which is a previous recording state.
FIG. 5B shows a recording current and a recording current for demagnetization.
FIG. 5C shows a recording state c, which is a degaussed state.
[0038]
FIG. 5 (d) shows a recording current. When magnetizing in the direction opposite to the direction of the demagnetized domain for writing 1, the writing timing is advanced by Δx, and the writing of 1 is the previous bit. If this occurs continuously, the write timing is delayed by Δy. When it is necessary to delay the timing by Δy to a position where the timing is delayed by Δx, the recording current is shifted by −Δx + Δy to adjust the writing timing.
[0039]
An embodiment of the present invention will be described with reference to FIG. 5 (d) and FIG. 5 (e).
For the data to be written at the position of the magnetic recording medium 21 corresponding to time t1, the write current write timing is advanced by Δx and the write current is applied at t1 ′ as in the case of FIG.
[0040]
The writing at time t2 is performed by inverting the magnetic domain in the same direction as the demagnetized magnetic domain, so this recording current is applied to the head without adjusting the write timing.
[0041]
At time t3, since 1 is written following time t2, it is necessary to delay the writing timing by Δy. Further, since this position is written by inverting the magnetic domain in the opposite direction to the demagnetized magnetic domain, it is necessary to advance the timing of applying the recording current by Δx. For this reason, the recording current is applied at time t3 ′, which is adjusted by −Δx + Δy with respect to time t3 (the writing timing is delayed by −Δx + Δy).
[0042]
At time t4, similarly to time t2, the recording current is applied without adjusting the data writing timing.
In writing at time t5, since it is necessary to advance the write timing of the recording current by Δx with respect to the data to be written, the write current is applied at t5 ′.
[0043]
For writing at time t6, 1 is written following writing at 1 at time t5, and the direction of the magnetic domain after recording is the same as the direction of the degaussed magnetic domain, so the timing of writing is delayed by Δy.
[0044]
FIG. 6 is a second embodiment of the present invention.
In FIG.
Reference numeral 2 denotes a magnetic recording signal generator.
[0045]
Reference numeral 41 denotes an AND circuit which inputs the NRZI signal (b) of the write data and the reverse phase of the clock signal (the reverse phase of c) and takes a logical product.
Reference numeral 42 denotes a flip-flop which inputs the output of the AND circuit 41 as a clock signal.
[0046]
Reference numeral 43 denotes a flip-flop, which receives the opposite phase of the clock signal (the opposite phase of c) and the D output of the flip-flop 42 as inputs.
Reference numeral 44 denotes a flip-flop, which inputs a clock signal and the opposite phase of the clock signal.
[0047]
An AND circuit 45 inputs the output of the flip-flop 43 and the output of the flip-flop 44 and takes a logical product.
Reference numeral 46 denotes an AND circuit which inputs a signal (b) and a reverse phase of the clock c and takes a logical product.
[0048]
47 is an AND circuit.
48 is an inverter.
Reference numeral 49 denotes an AND circuit.
[0049]
50 is a NOR circuit.
51 is an inverter.
52 is an AND circuit.
[0050]
53 is an AND circuit.
Reference numerals 61, 62, 63, and 64 denote delay circuits that delay T / 2, T / 2−Δx, T / 2 + Δy, and T / 2−Δx + Δy, respectively.
[0051]
65, 66, 67 and 68 are AND circuits.
Reference numeral 70 denotes a flip-flop.
FIG. 7 is a time chart of each signal in the operation explanatory diagram of Embodiment 2 of the present invention.
[0052]
In FIG.
(A) is write data.
(B) is the NRZI signal of the write signal.
[0053]
(C) is a clock signal.
(D) is a signal obtained by delaying the clock c by T / 2−Δx.
(E) is a signal obtained by advancing the clock c by T / 2 + Δy.
[0054]
(F) is a signal obtained by advancing the clock c by T / 2−Δx + Δy.
(G) is a signal generated for every other write data 1 in synchronization with the clock (c).
[0055]
(H) outputs H when the signals (g) and (i) are L. When the signal (h) is H, the delay circuit 61 is selected and the AND circuit 65 outputs a T / 2 clock.
[0056]
(I) is generated by a timed continuous 1 of write data.
(J) outputs H when the signal (g) and the signal (i) are H. When the signal (j) is H, the output of the delay circuit 64 is selected, and the AND circuit 68 outputs a clock of T / 2−Δx + Δy.
[0057]
(K) outputs H when the signal (g) is L and the signal (i) is H. When the signal (k) is H, the output of the delay circuit 63 is selected, and the clock of T / 2 + Δy is output from the AND circuit 67.
[0058]
(L) outputs H when the signal (g) is H and the signal (j) is L. When the signal l is H, the output of the delay circuit 66 is selected, and the clock of T / 2−Δx is output from the AND circuit 67.
[0059]
(M) is the output signal m of the OR circuit of FIG. 6, and (n) is the output signal n of the flip-flop circuit 70.
The operation of the configuration of FIG. 6 will be described.
[0060]
The AND circuit 41, the flip-flop circuit 42, the flip-flop 43, the flip-flop 44, and the AND circuit 45 generate a signal (g) having a rise corresponding to the odd-numbered value of the write data 1 in (a).
[0061]
The flip-flop 44 and the AND circuit 46 generate a signal (i) having a rising edge corresponding to the data value 1 that appears after the 1 data value 1.
The NOR circuit 50 and the AND circuit 53 generate a signal (a signal for selecting a clock delayed by T / 2) that becomes H when the signal (g) and the signal (i) are L and the output of the flip-flop 44 is H. To do.
[0062]
The AND circuit 49 receives the signal (g) and the signal (i) and generates a logical product signal (j) of the signal (g) and the signal (i) (a signal for selecting −Δx + Δy).
The inverter 51 and the AND circuit 52 generate a signal (k) that becomes H when the signal (g) is L and the signal (i) is H.
[0063]
The AND circuit 49, the inverter 48, and the AND circuit 47 generate a signal (l) that becomes H when the signal (j) is L and the signal (g) is H.
Then, the output of the T / 2 delay circuit is selected by the AND circuit 65 when the signal (h) is H. When the signal (l) is H by the AND circuit 66, the output of the delay circuit of T / 2−Δx is selected. The AND circuit 67 selects the output of the delay circuit of T / 2 + Δy when the signal (k) is H. The AND circuit 68 selects the output of the delay circuit of T / 2−Δx + Δy when the signal (f) is H.
By taking the OR logic of the outputs of the AND circuits 65, 66, 67, and 68 and using it as the clock input of the flip-flop 70, the signal (n) is obtained.
[0064]
FIG. 8 shows a third embodiment of the present invention.
In recent magnetic disk devices, not only the recording density but also the transfer speed are remarkably improved. Therefore, it is necessary to shorten the inversion time of the recording current.
[0065]
FIG. 8 shows the reversal of the recording current.
In the conventional recording method, since new data is overwritten and recorded in the previous history, it is necessary to switch the recording current from −I to + I or from + I to −I. However, in the present invention, an erased state (see FIG. 8C) is obtained by erasure, and therefore, when recording new data, it is only necessary to pass a current when forming a reverse magnetization reversal. . For example, in the case of FIG. 8, since erasing is performed with a negative current -I, no current is passed or only a positive current is passed during data recording. Therefore, in the present invention, data can be recorded at high speed.
[0066]
FIG. 8 (1) shows an example of how the recording current flows according to the present invention.
FIG. 8A shows the recording state A and the previous recording state of the magnetic recording medium 21.
[0067]
FIG. 8B shows a recording current for demagnetization, and indicates that demagnetization is performed by passing a recording current of −I.
FIG. 8C shows a recording state C in which the recording is demagnetized with the recording current -I.
[0068]
FIG. 8D shows the recording current, the solid line is the recording current of the present invention, and the dotted line is the conventional recording current.
FIG. 8E shows a recording state E, which is recorded with the recording current shown in FIG.
[0069]
As shown in FIG. 8D, data is recorded by passing a current of + I only when new data is recorded in the direction opposite to the demagnetized direction. A dotted line is a conventional method, and data is recorded with a current value of −I or + I. In this case, when writing of the data value 1 occurs subsequently, when changing from + I to -I, when the current value changes before reaching + I, or when changing from -I to + I, A change in the current value occurs before it completely falls to -I. For this reason, as shown in the drawing, a recording current of ΔI is reduced, and magnetization may not be performed accurately. However, in the case of the present invention, this is not the case because it is sufficient to increase + I from the current value 0 (see FIG. 8 (2)).
[0070]
FIG. 8 (2) shows the relationship between the magnitude of the recording current and the response time of the present invention.
In the present invention, + I is reached at time t1, but in the conventional case, -I is reached at time t2. Therefore, in the case of the present invention, as shown in FIG. 8 (d), the current value generated in the past does not decrease by ΔI.
[0071]
FIG. 9 shows a fourth embodiment of the present invention.
The fourth embodiment of the present invention is an embodiment for erasure, and erasing and recording are performed by the same head using a conventional head by performing recording after erasing.
[0072]
FIG. 9A is an explanatory diagram of the erasing method and the recording method.
21 is a magnetic recording medium.
The data recording area is erased in advance. For example, in the case of a floppy disk, data is erased by one rotation and data is recorded in the erased area.
[0073]
FIG. 9 (2) shows the apparatus configuration.
The control unit 29 generates an erasing control signal, and the erasing signal generating unit 24 generates a DC erasing signal. Then, the recording circuit 36 applies a DC erase signal to the head 23 to erase the magnetic recording medium 21.
[0074]
When recording a signal, the control unit 29 generates a signal recording control signal. The recording signal generator 25 generates a recording signal. The recording circuit applies a recording current to the head 23. The head 23 records data in the demagnetized area by the magnetic recording current.
[0075]
FIG. 10 shows a fifth embodiment of the present invention.
When performing DC erasure and recording with a single recording head, the response speed of the apparatus decreases. The seventh embodiment is for improving it.
[0076]
In the seventh embodiment, DC erasure is performed when data is erased (data file is erased). Generally, only the directory (data at a location where the attribute and size of the data are recorded) is deleted. Therefore, in the case of the present invention, depending on the user's wishes, the directory and data are erased or a flag for erasing the directory is set. Then, the data to be erased is searched based on the erasure flag when the device is idle, such as when there is no command to the disk device, and the directory and data are DC erased. At the time of recording, only data is recorded.
[0077]
However, in this case, when there is no area to be recorded, data to be erased may be searched, and when such data exists, it may be performed at the time of recording by requesting an erasure command.
[0078]
FIG. 10 (1) is a flowchart of the control unit according to the fifth embodiment of the present invention.
FIG. 10 (2) shows the data format of the magnetic recording medium.
In the fifth embodiment, for data to be erased, an erase flag is set in the directory of the magnetic recording medium.
[0079]
The fifth embodiment will be described with reference to FIG.
S1 Determine whether there is a command from the disk device. If there is, the process of S2 is performed, and if not, the process of S11 is performed.
[0080]
S2 Judge whether it is a read. If read, the process of S3 is performed. If not read, the process of S4 is performed.
S3 Data reproduction is performed.
[0081]
S4 Judge whether it is a write. If it is a write, the process of S5 is performed, and if it is not a write, the process of S6 is performed.
S5 Record new data.
[0082]
S6 Judge whether erased (erased). If erase (erase), the process of S7 is performed. If not erase, the process returns to S1.
S7: Determine whether to erase immediately. If it is erased immediately, the process of S9 is performed. If not erased immediately, the process of S8 is performed.
[0083]
S8 Set an erasure flag in the directory.
S9 DC deletes the directory.
S10 DC erases the data.
[0084]
S11 If there is no command to the disk device in the determination of S1, the data to be erased is retrieved.
S12 DC deletes the directory.
[0085]
S13 DC erases the data.
FIG. 11 shows a sixth embodiment of the present invention.
In the fourth embodiment of the present invention, 1 bit is written after erasing 1 bit.
[0086]
FIG. 11 shows an embodiment of a head for that purpose.
At present, MR heads are generally used as reproducing heads. Recording uses an inductive head. In the sixth embodiment, such a head is provided with an erasing head.
[0087]
In FIG.
Reference numeral 431 denotes a head.
An erase head 441 is used for erasing the recording.
[0088]
An inductive MR head 451 is used for writing and reproducing data.
Reference numeral 511 denotes an erasing upper magnetic pole, which is an erasing upper electrode.
[0089]
An erase gap 521 is a gap between the erasing upper magnetic pole and the lower magnetic pole.
Reference numeral 531 denotes an erasing lower magnetic pole, which is an erasing lower magnetic pole.
[0090]
Reference numeral 541 denotes an erase shield.
An upper magnetic pole 551 is an upper magnetic pole of a writing magnetic pole.
Reference numeral 561 denotes an upper shield / lower magnetic pole, which is a lower magnetic pole of a write magnetic pole. It also serves as a magnetic field shield.
[0091]
571 is an insulating layer (Al ₂ O _Three ), Which insulates the MR head.
Reference numeral 591 denotes a lower shield.
In this embodiment, in order to suppress the interference of the magnetic field between the recording head and the erasing head, a shield is provided between them (erase shield 541, upper shield / lower magnetic pole 561, lower shield 591). This shield may be made of a material similar to that used in conventional MR heads (for example, permalloy NiFe). In this embodiment, the MR head, the recording head, and the erasing head are used as the stacking order. However, any order may be used as long as the recording can be performed after the DC erasing is performed when the present invention is applied.
[0092]
FIG. 12 shows a seventh embodiment of the present invention.
FIG. 12A is a conceptual diagram of a rotary actuator that is the mainstream of the current head access mechanism. In this case, the head moves in a fan shape on the medium around the head actuator.
[0093]
FIG. 12 (2) is an enlarged view of the head portion of FIG. 12 (1).
Data is recorded on the medium in concentric circles (tracks). The head produces an angular deviation (yaw angle) with respect to the circumferential direction of the track (tangential direction of the track circumference). In conventional heads, recording is performed while overwriting the previous history, and since recording and playback are not performed simultaneously, there is a problem of angle deviation between recording and playback by giving a fixed offset during recording. Have dealt with.
[0094]
However, when erasing and recording are performed at the same time in the present invention, the problem of this angular deviation cannot be ignored as shown in FIG. In particular, when the recording density (TPI) in the track direction is increased and the positioning with respect to the track (off-track) is remarkable, by providing double actuators, the angular position shift as shown in FIG. Further, it is possible to eliminate the angle shift (see JP-A-6-187,624).
[0095]
【The invention's effect】
According to the present invention, when recording new data, the timing of applying the recording current is adjusted so that the recording position is not shifted due to the influence of the previous history state. Property can be remarkably improved. In addition, the recording density can be improved, and the performance of the magnetic recording apparatus can be improved.
[0096]
Regarding the above explanation, the following items are further disclosed.
(1) A magnetic recording apparatus for generating a magnetic recording signal for recording an electric signal on a magnetic recording medium, comprising: a recording head for recording data on the recording medium; and a recording signal generating apparatus for generating a recording signal. The generating device includes an erasing signal means for generating a signal for erasing already recorded data by magnetizing the magnetic recording medium in a certain direction before recording the data, and a magnetic domain recorded by erasing when recording the data. And a recording signal generating means for generating a magnetic recording signal for applying a recording current timing applied to the recording means earlier than a time at which a magnetic domain should be formed when magnetizing in a direction opposite to the direction of A magnetic recording apparatus for recording data after aligning the magnetization direction in a certain direction, the head comprising a recording head and a reproducing head, Recording head is to carry out a data erasure and data recording, a magnetic recording apparatus and recording the new data after erasing the recording head.
[0097]
(2) A magnetic recording apparatus for generating a magnetic recording signal for recording an electric signal on a magnetic recording medium, comprising: a recording head for recording data on the recording medium; and a recording signal generating apparatus for generating a recording signal, The generating device includes an erasing signal means for generating a signal for erasing already recorded data by magnetizing the magnetic recording medium in a certain direction before recording the data, and a magnetic domain recorded by erasing when recording the data. And a recording signal generating means for generating a magnetic recording signal for applying a recording current timing applied to the recording means earlier than a time at which a magnetic domain should be formed when magnetizing in a direction opposite to the direction of A magnetic recording apparatus for recording data after aligning a magnetization direction to a certain direction, wherein the head comprises an erasing head for erasing and a recording / reproducing head. The magnetic recording apparatus to obtain.
[0098]
(3) A magnetic recording apparatus for generating a magnetic recording signal for recording an electric signal on a magnetic recording medium, comprising: a recording head for recording data on the recording medium; and a recording signal generating apparatus for generating a recording signal, The generating device includes an erasing signal means for generating a signal for erasing already recorded data by magnetizing the magnetic recording medium in a certain direction before recording the data, and a magnetic domain recorded by erasing when recording the data. And a recording signal generating means for generating a magnetic recording signal for applying a recording current timing applied to the recording means earlier than a time at which a magnetic domain should be formed when magnetizing in a direction opposite to the direction of A magnetic recording apparatus for recording data after aligning the magnetization direction to a certain direction, wherein the direction of the recording / reproducing head and erasing head is the data To align in a recording direction, a magnetic recording apparatus, characterized in that it comprises an angle adjusting means for adjusting the angle of the head.
[0099]
(4) A magnetic recording apparatus for generating a magnetic recording signal for recording an electric signal on a magnetic recording medium, comprising: a recording head for recording data on the recording medium; and a recording signal generating apparatus for generating a recording signal, The generating device includes an erasing signal means for generating a signal for erasing already recorded data by magnetizing the magnetic recording medium in a certain direction before recording the data, and a magnetic domain recorded by erasing when recording the data. And a recording signal generating means for generating a magnetic recording signal for applying a recording current timing applied to the recording means earlier than a time at which a magnetic domain should be formed when magnetizing in a direction opposite to the direction of A magnetic recording apparatus for recording data after aligning the magnetization direction to a certain direction, wherein the direction of the magnetic domain after recording is the direction of the erased magnetization. The magnetic recording device and generates a recording signal for inverting the magnetic domain only if the opposite direction.
[0100]
(5) The method according to item 1, wherein when a data erasure request is made, the directory indicating the attribute of the recorded data and the selection of whether to erase the data or only to set the erasure flag in the directory are selected. A magnetic recording apparatus characterized in that if an erasure flag is set in the directory and there is no recording area when recording is performed later, an erasure command is requested, and data having the erasure flag is erased and recorded.
[0101]
(6) The method according to item 1, wherein when a data erasure request is made, the directory indicating the attribute of the recorded data and the selection of whether to erase the data or only to set the erasure flag in the directory are selected. The magnetic recording apparatus is characterized in that, when there is no request to the magnetic recording apparatus, the directory and data to be erased are searched from the flag and erased.
[Brief description of the drawings]
FIG. 1 is a diagram showing a basic configuration of the present invention.
FIG. 2 is an operation explanatory diagram of a basic configuration of the present invention.
FIG. 3 is a diagram showing Embodiment 1 of the present invention.
FIG. 4 is an operation explanatory diagram according to the first embodiment of the present invention.
FIG. 5 is an explanatory diagram of Embodiment 2 of the present invention.
FIG. 6 is a diagram showing a second embodiment of the present invention.
FIG. 7 is an operation explanatory diagram of Embodiment 2 of the present invention.
FIG. 8 is a diagram showing a third embodiment of the present invention.
FIG. 9 is a diagram showing a fourth embodiment of the present invention.
FIG. 10 is a diagram showing a fifth embodiment of the present invention.
FIG. 11 is a diagram showing a sixth embodiment of the present invention.
FIG. 12 is a diagram showing a seventh embodiment of the present invention.
FIG. 13 is an explanatory diagram of a conventional recording method.
[Explanation of symbols]
1: Magnetic recording device
2: Magnetic recording signal generator
3: Erase signal generation means
5: Recording signal generation means
7: Recording timing adjustment means
9: Control means

Claims (8)

In a magnetic recording apparatus for generating a magnetic recording signal for recording an electric signal on a magnetic recording medium,
A recording head for recording data on a recording medium;
A recording signal generating device for generating a recording signal,
The recording signal generating device includes an erasing signal means for generating a signal for erasing already recorded data by magnetizing a magnetic recording medium in a certain direction before recording the data;
A recording signal for generating a magnetic recording signal that applies a timing of a recording current flowing to the recording means earlier than a time at which a magnetic domain should be formed when magnetizing in a direction opposite to the direction of the magnetic domain recorded by erasure when recording data Generating means,
The recording signal generating means applies the recording current applied to the recording means to the recording medium at the time to be recorded based on the recording data and the clock signal, where Δx is a time that makes the recording current earlier than the time to actually record. A signal A having timing is generated, a signal B obtained by delaying the signal A by Δx is generated, and a recording current that is actually applied to the recording medium is generated by the signal A and the signal B,
A magnetic recording apparatus for recording data after aligning the direction of magnetization to be recorded on a recording medium in a certain direction.   When recording the new data, the recording signal generating device should actually record the magnetic domain at the timing when the recording current is supplied to the recording medium in order to compensate for the influence of the magnetization reversal several bits before in the new data. 2. The magnetic recording apparatus according to claim 1, wherein a recording signal to be applied later than the time is generated.   2. The magnetic recording apparatus according to claim 1, wherein a recording signal for reversing the magnetic domain is generated only when the direction of the magnetic domain after recording is opposite to the direction of the erased magnetization. The recording signal generating means includes a D flip-flop circuit for inputting a clock signal, a delay circuit for delaying the output of the D flip-flop circuit, and an output of the D flip-flop circuit delayed from the output of the D flip-flop circuit The magnetic recording apparatus according to claim 1, further comprising a circuit that outputs a logical sum of the two . Erasing signal generating means for generating a signal for erasing already recorded data by magnetizing the magnetic recording medium in a certain direction before recording data;
A recording signal for generating a magnetic recording signal that applies a timing of a recording current flowing to the recording means earlier than a time at which a magnetic domain should be formed when magnetizing in a direction opposite to the direction of the magnetic domain recorded by erasure when recording data Generating means,
The recording signal generation means applies the recording current applied to the recording means to the recording medium at the time to be recorded based on the recording data and the clock signal, when Δx is a time for making the recording current earlier than the time to actually record. A signal A having timing is generated, a signal B obtained by delaying the signal A by Δx is generated, and a recording current that is actually applied to a recording medium is generated by the signal A and the signal B. Recording signal generator. When recording the new data, the recording signal generating device actually records the timing at which the recording current is supplied to the recording medium in order to compensate for the influence of magnetization reversal several bits before in the new data. 6. The magnetic recording signal generating apparatus according to claim 5 , wherein a recording signal to be applied later is generated . The time when the recording current applied to the recording means is earlier than the time at which the recording should actually be performed is Δx, and the magnetic domain actually records the timing of supplying the recording current to the recording medium in order to compensate for the influence of magnetization reversal several bits before. For obtaining a clock whose timing is advanced by Δx based on the signal representing the write data and the clock signal, where Δy is a time for delaying the timing of applying the recording current applied later than the power time to the actual recording time. Based on the signal A and the clock signal, a signal B for selecting a clock having a clock signal timing delayed by Δy is generated.
A clock signal, a clock C that is advanced by Δx, a clock D that is delayed by Δy, and a clock E that is delayed by −Δx + Δy;
6. The magnetic recording signal according to claim 5, wherein the clock C, the clock D, and the clock E are selected based on the signal A and the signal B, and a recording current is generated based on the clock. Generator. The recording signal generating means includes a D flip-flop circuit for inputting a clock signal, a delay circuit for delaying the output of the D flip-flop circuit, and an output of the D flip-flop circuit delayed from the output of the D flip-flop circuit 6. A magnetic recording signal generating apparatus according to claim 5, further comprising a circuit that outputs a logical sum of the two .

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