JPH064984A - Recording control device - Google Patents

Abstract

(57) [Summary] [Purpose] A recording control device capable of setting a recording start position independently of the number of rotations of a magnetic disk. A magnetic head 3, a spindle motor 50 for rotating the magnetic head 3, a frequency transmitter 51 for transmitting an FG signal having a frequency proportional to the number of revolutions of the spindle motor 50, and one transmission for each rotation. A PG sensor 40 that detects a reference signal (PG signal) that is generated, a counting circuit 61 that counts the cycle of the FG signal, and a count that counts the time from the detection of the PG signal until the magnetic head 3 is positioned at the recording start position. FG having a circuit 66 and at a certain rotation speed
The count value of the signal cycle and the count value for setting the recording start position are stored in advance, and from the stored count value and the detected FG signal cycle to the recording start position from the detection of the PG signal according to the rotation speed and the recording method. The time required for the magnetic head 3 to be positioned is determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording control device, and more particularly to a recording control device when recording is performed by relatively cyclically driving a recording medium and a recording head.

[0002]

2. Description of the Related Art As an example in which a recording medium and a recording head are cyclically driven to perform recording, as an example in which the recording head is cyclically driven with respect to the recording medium, a magnetic tape moving like a VTR is used. As an example of a system in which a head provided on a rotary drum is rotationally driven, and a recording medium is cyclically driven with respect to the recording head, a magnetic disk as a recording medium rotates like a recording / reproducing device of a still video camera. An example is a system in which a recording head is driven and the recording head moves in the radial direction of the rotating magnetic disk.

In such a recording / reproducing method, the recording head provided on the rotating drum is switched or recording is performed on the rotating magnetic disk by detecting the rotational phase of the recording medium or the recording head which is cyclically driven. The recording timing to be executed is set.

An example of a method of recording on a rotating magnetic disk such as a still video by a magnetic head moving in the radial direction of the disk will be described below. In this case, it is standardized to set a data starting position (hereinafter referred to as "DSP") using a signal indicating a rotation phase called PG. More specifically, for example, the standard position of the DSP in the NTSC system is the position on a line drawn in the radial direction through the PG pin on the magnetic disk that is the basis of PG signal transmission and the center of the magnetic disk. The format is determined so that the leading edge of the vertical synchronizing signal of the video signal is recorded within a range of ± θ ₀ (= 1 ° 22 ′) from the position.

In order to adapt to such a format, in the conventional recording / reproducing apparatus, the mechanical positional relationship between the PG head for detecting the PG signal and the magnetic head is adjusted, or the operation timing of the magnetic head is electrically adjusted. It has to be adjusted and such adjustments are made during production.
For such adjustment, Japanese Patent Laid-Open No. 63-127466.
Apparatuses such as those described in U.S. Pat.

On the other hand, in the above recording / reproducing method, in order to cope with a high-definition image, for example, the rotation of the magnetic disk can be sped up to widen the band of the recording signal. However, each of the above-mentioned devices is an adjustment method when the number of rotations of the magnetic disk and the recording method (standard) are specified, and the user can adjust the number of rotations of the magnetic disk and the recording method (standard). (Eg from NTSC system to PA
It cannot be used when recording / reproducing is performed (switching to the L system).

For this reason, once the rotational phase is finely adjusted during production, the recording / reproducing apparatus becomes compatible with a single rotational speed and recording system (standard), and the user is There has been a problem that the number of rotations of the disc and the recording method (standard) cannot be freely changed and used.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording control device which allows a user to set a plurality of periodic rotation speeds and recording systems (standards).

[0009]

Such an object is achieved by the present inventions (1) and (2) described below.

(1) A magnetic head, rotating means for rotating the magnetic disk relative to the magnetic head, reference signal generating means for transmitting a reference signal for each rotation of the magnetic disk, and the magnetic disk. And a time measuring means for detecting the number of rotations of the magnetic head, and setting the time from the transmission of the reference signal until the magnetic head is located at the recording start position on the magnetic disk, A recording control device for identifying the recording start position according to a set time, wherein the set time is adjusted according to the number of rotations of the magnetic disk detected by the number-of-rotations detecting means.

(2) A magnetic head, rotating means for rotating the magnetic disk relative to the magnetic head, reference signal generating means for transmitting a reference signal for each rotation of the magnetic disk, and the magnetic disk. And a time measuring means for detecting the number of rotations of the magnetic head, and setting the time from the transmission of the reference signal until the magnetic head is located at the recording start position on the magnetic disk, A recording control device for identifying the recording start position according to a set time, wherein the set time is adjusted according to a change in the recording start position.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The case where the recording control device of the present invention is used in a still video camera will be described in detail below with reference to the accompanying drawings. FIG. 1 is a partial block diagram of a recording control device used in a still video camera.

In FIG. 1, 2 in the upper left of the drawing is a magnetic disk which is a recording medium, and 3 is the magnetic disk 2.
A magnetic head as a recording head for recording a signal to or reproducing a signal from the magnetic disk 2, 40 is a PG pin 2
The magnetic flux from 1 is picked up and the reference signal (hereinafter “PG
PG sensor as a reference signal generating means for generating a signal. As shown in FIG. 2, the positional relationship between the magnetic head 3 and the PG sensor 40 on the surface of the magnetic disk is a straight line drawn from the center of the magnetic disk 2 toward the magnetic head 3 and the PG sensor 40. The positional relationship is such that the angle is, for example, θ ₁ = 0 ° ± θ ₀ °.

As will be described later, in the present invention, the position of the PG sensor 40 with respect to the magnetic head 3 does not have to be at the angle θ ₁ , but has a certain angle in the direction shown in FIG. Just do it. In other words, the PG sensor 4
0 may be before the magnetic head 3 in terms of timing. 41 is a waveform shaping circuit, which amplifies the PG signal,
The input signal to the control circuit 10 described later is shaped into digital signals 0 and 5 as compared with the reference voltage.

Further, in FIG. 1, 50 is a spindle motor as a rotating means for rotating the magnetic disk 2 which is a periodic drive, and 51 is an output signal having a frequency proportional to the rotational speed of the spindle motor 50. (Hereinafter referred to as "FG signal"), a frequency oscillator (hereinafter referred to as "FG") as a rotation speed detecting means, 52 is a motor drive circuit for driving the spindle motor 50, and 53 is an FG signal. A speed control circuit that detects the rotation speed of the spindle motor 50 and keeps it constant, 54 is a phase control circuit that controls the rotation phase of the motor based on a synchronization signal and a DLYPG signal, which will be described later, and 55 is a waveform shaping circuit. Amplifies the FG signal, compares it with a reference voltage, and shapes the input signal to the control circuit 10 described later into a digital signal. A.

10 is based on the PG signal and FG signal,
The control circuit outputs a DSP signal and a DLYPG signal at a predetermined timing, and is configured by, for example, a microcomputer. Reference numeral 11 is a memory from which necessary information is appropriately input to the control circuit.

Based on the input PG signal and FG signal, the control circuit 10 adjusts the output timing of the DSP signal and the DLYPG signal so as to match the format on the magnetic disk in accordance with the rotation speed of the spindle motor 50. adjust.

Reference numeral 60 is a system control circuit for controlling the operation of each part of the still video camera, 61 is a camera block for controlling a camera mechanism such as image input by a CCD and release and zoom driving, and 62 is for image processing. A video circuit 63 performs an input unit for inputting various information and instructions to the system control circuit 60, and a display unit 64 displays an operating state.

Reference numeral 70 is a switch for selecting either recording or reproduction, and 71 is a recording circuit for modulating and amplifying the image signal. 72 is a DSP of the control circuit 10
This is a gate that enables recording on a magnetic disk based on the transmission of a signal. Reference numeral 73 is a reproduction circuit, 74 is a sync signal separation circuit for synchronously separating a reproduction sync signal from a reproduction signal, and 75 is a switch that switches in synchronization with the switch 70 at the same time.

The following control signals are output from the system control circuit 60. C for the camera block 61
A control signal P ₁ for controlling the CD, the photographing mechanism, etc. is output. A control signal P ₂ for operating the switching of the frequency of the Ref synchronization signal and a control signal P _{3 for} various image processings are output to the video circuit 62. Sync signal separation circuit 74
On the other hand, when the PAL system / NTSC system is selected, a control signal for switching the circuit characteristics is output in order to detect a synchronization signal matching the system.

Speed control circuit 53 and phase control circuit 54
In contrast, when the PAL system / NTSC system is selected, a control signal for controlling the rotation speed and phase of the spindle motor 50 according to the system is output. For the control circuit 10, the PAL system / N
Based on the switching of the TSC system, a control signal indicating a value to be read from the memory (N _ref , N _rep1 , N _rep2 described later) is output.

The information input from the input section 63 is as follows:
For example, selection of a high-definition image (changing the number of rotations of the spindle motor 50), selection of PAL system / NTSC system, shooting conditions, release switch, reproduction instruction, etc.
The information displayed on the display unit 64 includes the presence / absence of high-definition image capturing, the display of the selected PAL system / NTSC system, the capturing conditions, the track position, the battery check, and the like.

FIG. 3 is a plan view of the magnetic disk 2.
The DSP position 22 is a position obtained by drawing a line in the radial direction that passes through the center of the magnetic disk and the PG pin on the magnetic disk that is the basis of PG signal transmission, and is the recording start position defined by the standard. Also, the leading edge of the vertical sync signal (V-sync leading edge) (DLYPG position) 2
3 is located 7H ± 2H after the DSP position as a video signal.

Here, the DSP signal means the magnetic disk 2
Signal is transmitted at the same timing as when the DSP position 22 passes through the magnetic head 3 during the rotation of DLY.
The PG signal means that the DLYPG position 23 is the magnetic head 3
It is a signal transmitted at the same timing as when passing through. Here, the DSP position 22 and the DLYPG position 2
The positional relationship of 3 is 7H ± as a video signal as described above.
Although there is a difference of 2H, the angle formed by the straight line drawn in the radial direction from the center of the magnetic disk 2 through each of the above positions differs depending on the recording system (standard). In the PAL system, the rotation speed is 3000 rpm and θ = 8. ° 4 '± 2 ° 18', NT
In the SC method, at a rotation speed of 3600 rpm, θ = 9 ° 3
6 '± 2 ° 45'.

The DLYPG signal is used for controlling the phase so that the phase difference becomes zero by comparing the phase with the reproduction synchronization signal obtained by the synchronization separation from the synchronization signal separation circuit 74 in the reproduction mode. In the recording mode, the phase is controlled by comparing with the internally generated Ref sync signal.

The calculation in the control circuit 10 is performed by the DSP.
The output timing of the signal or DLYPG signal is defined by the time from the transmission of the PG signal to the output of each signal (hereinafter referred to as "set time") with the PG signal as a reference, and when the time elapses, each of the above Output a signal.

A method of calculating the set time will be described. The cycle of the FG signal at a certain rotation speed of the spindle motor 50, the time from the transmission of the PG signal until the DSP position of the magnetic disk 2 reaches the position of the magnetic head 3, and the DSP position passing through the magnetic head 3 further. The time from when the DLYPG position reaches the position of the magnetic head 3 is measured and stored in advance. A timer built in the control circuit 10 can be used as a time measuring means for measuring this time. This timer is a clock generator,
By oscillating a clock pulse of a predetermined frequency and counting the number of this clock pulse, the time is measured by the counted number. (Hereinafter, the count value obtained by counting the number of clock pulses is referred to as the count number.)

FIG. 4 is an operation waveform diagram of the clock pulse, PG signal and FG signal in this embodiment. Hereinafter, the count number of the cycle of the FG signal (FIG. 4 (a)) at a certain rotation speed is N _ref (FIG. 4 (b)), and the DSP position of the magnetic disk 2 from the transmission of the PG signal (FIG. 4 (c)). The count number of time to reach the position of the magnetic head 3 is N
_rep1 (FIG. _4D ), the count number of the time from when the DSP position of the magnetic disk 2 passes the position of the magnetic head 3 until the DLYPG position reaches the position of the magnetic head 3 is N
_rep2 . Then, each count value is stored in the memory 11.

The count number of N _rep1 is set after setting the magnetic disk on which the detection signal is recorded at the DSP position and detecting the PG signal by the PG sensor 40 (FIG. 4 (c)).
The detection signal of the DSP position is obtained by counting the number of clock pulses until the magnetic head 3 detects the magnetic head 3 (FIG. 4E) (FIG. 4D). N _rep2 can be _{obtained in the} same manner.

The number of counts N _fg (FIG. 4 (g)) of the cycle of the FG signal (FIG. 4 (f)) at the number of rotations used by the user (hereinafter referred to as “used rotation number”) is counted. Then, N _pg1 and N _rep2 are respectively multiplied by N _fg / N _ref to calculate N _pg1 and N _pg2 , respectively.

[0031]

[Equation 1]

[0032]

[Equation 2]

This N _pg1 is the number of clock pulses from the transmission of the PG signal at the number of revolutions used until the DSP position of the magnetic disk 2 reaches the position of the magnetic head 3, and N _pg2 is the magnetic disc at the number of revolutions used. D of 2
After the SP position has passed the position of the magnetic head 3, DLYP
The number of clock pulses is the time required for the G position to reach the position of the magnetic head 3.

The number of clock pulses is counted from the transmission of the PG signal, the DSP signal is transmitted when the count number becomes equal to N _pg1, and the DLYPG signal is transmitted when it becomes equal to [N _pg1 + N _pg2 ]. That is, DSP
The set time to output the signal is specified by N _pg1 , and DLYP
The set time for outputting the G signal is specified by [N _pg1 + N _pg2 ]. Thus, by setting the transmission timing of each signal according to time, the transmission timing of the signal can be set according to the rotation speed of the spindle motor 50.

Since the above operation defines the timing of recording each signal (recording start position on the magnetic disk) according to the number of clock pulses, for example, the standard for recording on the magnetic disk is changed and the recording start position is changed. Even if the basic values N _ref , N _rep1 , and
By _changing N _rep2 to a value that _conforms to the standard, it is possible to operate according to each standard. Basic value N _ref This per each standard, N _{re p1,} N _rep2, including advance stored in advance in the memory, each time switching the standards, the control circuit 1
It suffices to switch the value 0 read from the memory.

In the recording control device having the above configuration, the PG
Signal and FG signal, DSP signal and DLYP
The operation of the control circuit 10 when generating the G signal will be described based on the flowcharts shown in FIGS. 5, 6 and 7.

The magnetic disk 2 is set and the rotating means of the magnetic disk 2 is rotated. It is judged whether the standard for recording on the magnetic disk 2 is the PAL system or the NTSC system (step 101), and N corresponding to each system is determined.
The values of _ref , N _rep1 , and N _rep2 are read from the memory 11 (steps 102 and 103). Magnetic disk 2
Wait until the rotation of the
4) When the first PG pulse after being locked is detected (step 105), zero is input to the memory N of the FG pulse count number, and zero is input to the memory N _fg of the clock pulse count number of the FG signal cycle. Enter.

Further, an FG for measuring the cycle of the FG pulse
The timer and the count of the PG timer for measuring the signal output timing from the PG pulse are cleared (step 106). In the control circuit 10 of the present embodiment, the clock pulse frequencies for measuring the cycles of the FG pulse and the PG pulse are different, the clock pulse frequency for measuring the FG pulse is 6 MHz, and the clock pulse frequency for measuring the PG pulse is 375 KHz. .

When the first FG pulse is detected (step 107), 1 is added to the value of N (N = N + 1) F
A counter for counting clock pulses for measuring the G pulse period is started (step 108). When the next FG pulse is detected (step 109),
The counter is stopped (step 110), and it is judged whether or not the memory N of the count number of the FG pulse is 1 (step 111). If N = 1,
Enter the count number of the counter in N _fg ,
Clear the count value of the counter that counts the clock pulse that measures the pulse period (step 11
2), steps 108 to 110 are executed again.

By this re-execution, the value of the memory N becomes a value other than 1 (= 2). If N = 1 is not satisfied, N = 16.
It is determined whether or not (step 113). N ≠ 16
If it is, the value obtained by dividing the sum of the counter value at this time and the value of N _fg by 2 (the average of N _fg and the counter value) is input to N _fg, and the cycle of the FG pulse is measured. The count value of the counter for counting the clock pulses to be cleared is cleared (step 114).

Next, the above steps 108 to 114 are repeatedly executed, and when N = 16, N _ref , N
_{From the values of rep1} , N _rep2, and N _fg obtained in steps 108 to 114, N _pg1 and N _pg2 are calculated by the above-described mathematical formulas 1 and 2 (step 115). That is, even if the user selects a high-definition image and the rotation speed of the spindle motor 50 changes, N _fg that matches the rotation speed is obtained, and appropriate N _pg1 and N _pg2 are calculated. .

Wait for detection of PG pulse (step 11
6) When this is detected, the counting of the PG timer for measuring the signal output timing from the PG pulse is started (step 117). It is judged whether or not this count value has reached the calculated N _pg1 (step 11).
8), when N _pg1 is reached, a DSP signal is output (step 119). From the detection of the PG pulse, DL
Count N until the timing of outputting the YPG signal
_pg3 (time) can be calculated by N _pg1 + N _pg2 ,
This calculation is performed to determine N _pg3 (step 120).

The count value of the PG timer is the above N _pg3
(Step 121), the DLYPG signal is output when N _pg3 is reached (step 12).
2). Next, the counting of the PG timer is stopped (step 123), and it is judged whether or not the reproduction or recording operation is completed (step 124). If it is not completed, the procedure returns to step 106, and if it is completed, Exit the program.

By the above operation, recording and reproduction by the magnetic head can be started from an appropriate position. Further, since the values of N _rep1 and N _rep2 may be set according to the position of the attached magnetic head 3,
Due to the relationship with the DSP position and DLYGP position of the magnetic disk, the mounting position of the magnetic head 3 is not restricted, and the design range of the recording / reproducing device is widened. Further, as described above, each manufactured device is loaded with a reference disk having a detection signal at the DSP position or the DLYPG position, and N
_All that is _required is to store _{re f} , N _rep1 , and N _rep2 in the memory 11. Specifically, since it is possible to adjust each device only by loading the reference disk, it is not necessary to perform mechanical fine adjustment or electrical adjustment of the mounting position of the magnetic head 3 when assembling the device, and the adjustment work can be performed. Becomes extremely easy.

[0045]

As described above, according to the recording control method of the present invention, the mounting accuracy of the recording head or the like is eased,
Not only the adjustment work is unnecessary, but also when a plurality of periodic drive speeds and recording methods are changed, it is possible to accurately start recording from the recording start position without changing the mechanical position. Therefore, there is an advantage that a single printing apparatus can be provided with versatility such that it can handle a plurality of printing methods and the number of rotations of the spindle motor. Moreover, this switching has an effect that the user can freely switch.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording control apparatus that implements a recording control method of the present invention.

FIG. 2 is a plan view showing a positional relationship between a PG sensor and a magnetic head.

FIG. 3 is a plan view of the magnetic disk showing DSP positions and DLYPG positions of the magnetic disk.

FIG. 4 is an operation waveform diagram in the present embodiment.

FIG. 5 shows a part of a flowchart showing the operation of the control circuit, and shows steps 101 to 107.

FIG. 6 shows a part of a flowchart showing the operation of the control circuit, and shows steps 108 to 115.

FIG. 7 shows a part of a flowchart showing the operation of the control circuit and shows steps 116 to 124.

[Explanation of symbols]

 10 control circuit 11 memory 2 magnetic disk 21 PG pin 22 DSP position 23 DLYPG position 3 magnetic head 40 PG sensor 41 waveform shaping circuit 50 spindle motor 51 frequency transmitter (FG) 52 motor drive circuit 53 speed control circuit 54 phase comparison circuit 55 Waveform shaping circuit 60 System control circuit 61 Camera block 62 Video circuit 63 Input section 64 Display section 70 Switch 71 Recording circuit 72 Gate 73 Playback circuit 74 Sync signal separation circuit 75 Switch 101 to 124 steps

Claims (2)

[Claims] 1. A magnetic head, rotating means for rotationally driving a magnetic disk relative to the magnetic head, reference signal generating means for transmitting a reference signal for each rotation of the magnetic disk, and It has a rotation speed detecting means for detecting the rotation speed and a time measuring means, and sets the time from the transmission of the reference signal to the magnetic head being located at the recording start position on the magnetic disk. An apparatus for specifying the recording start position according to time, wherein the set time is adjusted according to the number of rotations of the magnetic disk detected by the number-of-rotations detecting means. 2. A magnetic head, rotating means for rotationally driving the magnetic disk relative to said magnetic head, reference signal generating means for transmitting a reference signal for each rotation of the magnetic disk, and said magnetic disk It has a rotation speed detecting means for detecting the rotation speed and a time measuring means, and sets the time from the transmission of the reference signal to the magnetic head being located at the recording start position on the magnetic disk. An apparatus for identifying the recording start position according to time, wherein the set time is adjusted according to a change in the recording start position.