JPS6273469A - Rotary magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To detect a specified track without providing a special sensor, such as an optical sensor, etc. by recording a specified track detecting signal on a portion synchronized with the portion where a servo signal is written. CONSTITUTION:At an area possible to record and reproduce where the servo signal has not been written, the switching of a head is selected by a head switching signal 32 from an outside controller. The reproducing signal of the head selected by the signal is amplified at an amplifier 27, and at a band-pass filter 33, its S/N is improved, and at a differentiation circuit 34, the inclination of the signal at the inverting part of magnetic flux is made steep. The signal is converted to a digital signal at a comparator 35, a required pulse width being generated at a pulse generator 36, and outputting a read data 37. The position error signal of the head operates a control circuit 38 in order that the center of the head is coincident with that of a track by a motor control circuit 39 and a head driving motor 40 is operated to move the head.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to specific track detection in a single-rotation type magnetic recording/reproducing device.

[Conventional technology]

A method for detecting a specific track in conventional rotary magnetic recording and reproducing equipment is carried out using a combination of an optical sensor and a closing plate that moves as the head moves. In addition, the specific track is an example of a rotary one-chip recording and reproducing device, 5
In a 4-inch hard disk, these tracks are provided on the outer periphery and are called XX tracks. As a method for detecting the XX track.

The XX track was detected by providing a track on which a detection signal was written on the outer periphery of the 't'a track, reproducing the detection signal with a head, and determining this in a control circuit.

[Problems and Objectives to be Solved by the Invention] However, in the above-mentioned prior art, when the track'M degree increases, the combination of the optical sensor and the shielding plate will not work for a long time due to secular changes in the amount of light, changes in m degrees, etc. Stability cannot be guaranteed.

In addition, in the method of recording a detection signal on the outer circumference of the "LX" rack, the head moves between the XX track and the innermost recordable/reproducible track in an abnormal operating state, so the XX track In general, the detection cannot be carried out, and the rotary magnetic recording and reproducing device must be put into a special operating state.

When a track further outside the XX track or a track further circumferential than the innermost track enabled by the rotary magnetic recording/reproducing device is selected by an external controller, 'Q, '11. 7) If a problem occurs in the movement of the head, the rotation will be stopped until a controller controlling the external rotary magnetic recording/reproducing device determines that the head is moving. The type magnetic recording/reproducing device could not detect the problem at all.

[Means for solving problems]

In the rotary S-air recording and reproducing apparatus of the present invention, recording is performed from an external controller in a portion synchronized with a portion where servo information for head positioning that cannot perform a data write operation is written. It is characterized in that a signal for detecting a fixed track is recorded.

[Effect]

According to the present invention, in normal operating conditions, the control circuit of the rotary recording/reproducing apparatus can detect when a problem has occurred in the movement of the head, and when the XX track can be detected, the external It is possible to move to the XX track without requiring any special instructions from the controller. [Embodiment] FIG. 1 shows an embodiment of the present invention. FIG. 2 is a diagram ( ) for explaining a portion where servo information and a specific track detection signal are recorded, and (b) is an example layout diagram of detection signal information for specific track detection.

An example of a rotary magnetic recording and reproducing device is a device that reproduces servo information called an index servo once per rotation of a 5 inch hard disk and corrects the position of the head. A signal 1 and a special track detection signal 2 are provided, and are reproduced by heads 3 and 4, respectively. A control block diagram of the device is shown in FIG. A spindle motor that rotates the magnetic recording medium 5 at a constant rate has a
An index indicating the start of rotation is provided once per rotation.

The index detector 20 detects a substance (generally #i magnet) attached to a part of the spindle motor that indicates the start of rotation and converts it into an electrical signal. After this is converted into a digital signal by a comparator 21, a pq pulse generator 22 makes the pulse width constant. The relationship between the input signal 1 and the index is as shown in FIG. A signal (1) from the spindle motor is generated, which produces a servo detection signal (2) in which the servo signal is recorded6 (2
), an index signal (3) indicating the start of data recording/reproduction is output to the external controller. In the case of the 5T506 interface, which is an example of the interface, the rotation speed of the spindle motor and T4 are determined so that τ3=1&6m5ec. Therefore, the index signal of the spindle motor is delayed by the pulse generator 25 and becomes index (5). Pulse generator 2
A servo detection signal (2) that detects the portion where the servo signal 1 is recorded is outputted by the signal from 2.

Servo signal 1 is reproduced by head 3. head 1
The switching is performed by the head switching circuit 26.

The reproduced original signal is electrically amplified to a necessary size by an amplifier circuit 27, a bandpass filter 28 extracts the necessary signal band, and a servo detection switch 29 separates the position signals of the inner and outer circumferences. The servo detection circuit 50 makes the 1V position signals for the inner and outer circumferences electrically stable, and the position error detection circuit 51 generates position error signals for the inner and outer circumferences.

In areas where servo signals are not written and can be recorded and played back,
Head switching is selected by a head switching signal 62 from an external controller.The reproduced signal of the selected head is amplified by an amplifier 27, improved in % S/N by a bandpass filter 33, and differentiated. In circuit 34,
Make the slope of the signal steeper in the part where the magnetic field is reversed. The comparator 35 converts this into a digital signal, the pulse generator 36 generates the necessary pulse width, and the read data 57
Output. The head position error signal is used by the control circuit 38 to operate the motor control circuit 1859 and drive the head drive motor 40 in order to align the center of the head with the center of the track.
to move the head. In the 5T506 interface, movement of the head between tracks is performed by a direction signal 41 that determines the direction of the inner and outer circumferences and a step signal 42 that determines the number of tracks to be moved. In the index servo mechanism, since the servo signal is not always input, the head and drive motor 40 must maintain a certain state determined by the motor control circuit 59, which cannot be easily done with a step motor. Ru. -For example, in a combination of a step motor, a D/A converter, and a current-controlled DC motor drive circuit,
The control circuit 58 is.

When receiving head movement commands from an external controller,
The motor control circuit 59 is operated for the number of core machine tracks, and the step motor is stopped at a stable point determined by the current ratio flowing through the excitation coil of the step motor. After the head reaches the target track, a period called settling is required until the head stops. This is a period to stabilize the vibration of the mechanism that moves the head.
It is about 15m5eC. After stabilizing the shooting,
Performs signal processing such as servo signals and magnetic recording/reproduction 6
Specific tracks, here - for example, on the outer periphery\
\Let's talk about track detection. \\The track detection signal is assigned to the part 2 in Figure 1 (,), and the control circuit 6
The servo head switching signal 45 from 8 generates the servo detection signal 25, and just in case, the servo signal 1 or
The track detection signal 2 can be selected. The track detection signal 2 includes a signal as shown in FIG. 1(b). The signal consists of a portion 6 where magnetization reversal is recorded and a portion 7 where no magnetization reversal is recorded. Magnetization reversal can be recorded in the range of 1.25 MHz to 2.5 MHz in the E3'I'506 interface using a bandpass filter. The track detection signal 2 part can be divided into three parts, A, E, and 0 parts from the front in the direction of head movement 9.

A signal is recorded in the A and 0 portions. Furthermore, signals are recorded in the A and B portions of the outer track 10, and in all of the ldA, B, and C portions of the inner track 11 near the \\ track. Further, no signal of magnetization reversal is recorded on the inner track. Using the servo detection circuit 50 and the position error detection circuit 51, the control circuit 58 can detect the magnitude of the signal at the A, B, and 0 portions. Servo detection circuit 5
0 consists of a hold circuit and a sampling circuit, and extracts the state of the signal at a certain time from the beginning of the index. This is a position error detection circuit 5 consisting of an A/D converter.
1 to convert it into a digital value, which is judged by the control circuit 38 consisting of a CPU. −, Immediately after moving Rad,
By setting the servo head switching signal to read the X\track detection signal, the track at a, 11 can be sufficiently detected in normal operating conditions. Furthermore, since the reproduced value at the time of non-magnetization reversal is stable, the presence or absence of a signal is excellent as a detection means. Also, when writing servo signals, you can write them using the same method.

〔Effect of the invention〕

As described above, according to the present invention, by recording the fixed track detection signal in the part synchronized with the part where the servo signal is detected, the detection signal can be detected without providing a special sensor such as an optical sensor. Can detect specific tracks. In addition, in normal operation, when a specific track is selected, it is possible to confirm whether a problem occurs in the head movement WJ, so if a problem occurs, it will not become a liability to the external controller. This has the effect of being able to deal with

[Brief explanation of drawings]

FIG. 1 shows a recorded partial diagram (a) and a layout diagram of detection signal information (a) for explaining the specific track detection method of the present invention. FIG. 2 is a control block diagram of the rotary magnetic recording/reproducing device. Figure 3 shows four explanations of the operation of servo signals and indexes. 1... Servo signal 2... Specific track detection signal 6.4... Head 5... Discipline medium 6... Field Part 7 where the conversion is reversed by the T needle...
...Part 8 where canning reversal is not recorded...
\\Track center 9...Head movement direction 10...\\Outer track 11 from the track
...＼Inner track near the track 12...
... Inner track 20 ... Index detector 21.35 ... Comparator 22.25.56 ... Pulse generation i26 ...
... Head switching circuit 27 ... Amplifier 28.35 ... Bandpass filter 29 ... Servo detection switch 50 ... Servo detection circuit 31 ... ...Position error detection circuit 32...Head switching signal 64...Differentiating circuit 67...Read data 58...Control circuit 39... Motor control circuit 40...Head drive motor 41...Direction 42...Step (1)...Signal from spindle motor (2)
... Servo detection signal (5) ... Index signal TI ... Detection from spindle motor T2 ... Time required for one rotation T3. ...16 for 5T506 interface
．． 6m5ee T4... Servo detection signal width or more

Claims (1)

[Claims] To position the heads in a rotary magnetic recording/reproducing device that has a plurality of heads and in which information for positioning the heads for purposes other than recording/reproduction is recorded on a recording medium for performing magnetic recording/reproduction. synchronize with the information of
A rotary magnetic recording/reproducing device characterized by providing a signal for detecting a specific track.