JPH02206980A - Magnetic disk reproducing device - Google Patents

Abstract

PURPOSE:To attain fade-in and fade-out reproduction without use of a large sized and expensive device by controlling a 1st and 2nd switches with a field alternate signal and an output signal of a phase comparator circuit so that the phases of output picture signals of the 1st and 2nd switches are coincident. CONSTITUTION:The 1st and 2nd switches 6, 16 are controlled by a field alternate signal B and an output signal D of a phase comparator circuit 11 so that the phases of output picture signals of the 1st and 2nd switches are coincident. Then the 1st and 2nd switches are subject to switching control to output 1st and 2nd picture signals whose skew distortion is corrected and having the same continuity of the horizontal synchronizing signal are outputted respectively to the output terminal of the 1st and 2nd switches 6, 16. Thus, the special reproduction of fade-in and fade-out is attained at the changeover from the preceding pattern to the succeeding pattern on the monitor screen without using a large sized and expensive device such as a memory.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a magnetic disk reproducing device, such as a still image reproducing device for an electronic still camera system.

(b) Conventional technology The electronic still camera was published in the magazine "Shashin Kogyo J 19", for example.
September 1984 issue P, 101-P, 105 and 1984 1
As introduced in the October issue P, 99-P, 103,
One field of still image signals is recorded on each of a plurality of concentric recording tracks provided on a rotating magnetic disk called a video floppy, and this electronic still camera records field images on one video floppy. It is possible to record 50 still images and 25 frame images (50 tracks), and when recording, the recording is normally done sequentially from the outermost track (first trunk) to the inner trunk.

(c) Problems to be Solved by the Invention Incidentally, in order to perform characteristic reproduction such as fade-in/fade-out, a large and expensive device using an image memory is required. The object of the present invention is to enable fade-in/fade-out playback without using such a large-scale device.

(d) Means for Solving the Problems In order to solve the above problems, the magnetic disk reproducing apparatus of the present invention detects the rotational phase of a rotating magnetic disk having a plurality of recording tracks, and generates a PG pulse. a field alternating signal generation circuit that receives the PG pulse and generates a field alternating signal; a first head that obtains a first field reproduction signal from one recording track of the rotating magnetic disk; and the first head. a first demodulation circuit that demodulates the first field reproduction signal obtained in , a first synchronization separation circuit that separates a first synchronization signal from the first field reproduction signal, and an output of the first demodulation circuit. a first delay circuit that delays the output by 1/2H (H: horizontal scanning period); and a first switch means that selectively selects and outputs the output of the first demodulation circuit and the output of the first delay circuit. a second head for obtaining a second field reproduction signal adjacent to the two tracks of the rotating magnetic disk; and a second demodulation circuit for demodulating the second field reproduction signal obtained by the second head. a second synchronization separation circuit that separates a second synchronization signal from the second field reproduction signal; a second delay circuit that delays the output of the second demodulation circuit by 3AH; a second switch means that selectively selects and outputs the output and the output of the second delay circuit; and a phase comparison that detects whether the first synchronization signal and the second synchronization signal match or differ in phase. and a fade circuit that receives image signals output from each of the first and second switch means and performs a fade operation based on these image signals, and the first and second switch means 1. The second switch means is controlled by the field alternating signal and the output signal of the phase comparison circuit so that the phases of the output image signals coincide with each other.

(e) Effects According to the above configuration, a fade-in/fade-out effect can be easily obtained even if the signals of adjacent recording tracks are in different fields.

(F) Embodiment 1 An electronic still camera system embodying the present invention will be described with reference to the block diagram of FIG. 1 and FIG. 2 which is an operational waveform diagram thereof.

In FIG. 1, (1) is a rotating magnetic disk on which a plurality of recording tracks are provided concentrically, and this disk is rotated at high speed by a spindle motor (not shown) during recording and reproduction. Image signals for one field are recorded on each of the recording tracks. (Hl) (Hl
) is the first inline type. The first and second heads (H+) (H,) are arranged so as to be able to extract signals from adjacent recording tracks, respectively.

The first reproduction signal obtained by the first head (H,) is amplified by the first preamplifier (2) and then sent to the first demodulation circuit (3).
) and is supplied to the first synchronous component M circuit (port). The output of the demodulation circuit (4) is sent to the first % delay circuit (
5) through the first input terminal (6a) of the first switch (6).
It is also supplied directly from the demodulation circuit (3) to the second input terminal (6b). Said first synchronous separation circuit (4)
The synchronizing signal obtained from the first blanking pulse generation circuit (7) is supplied to a first blanking pulse generation circuit (7), where a blanking pulse is generated and applied to the first blanking circuit (8). This first blanking circuit (8) blanks the synchronization signal of the image signal obtained from the output terminal (6c) of the first switch (6), and sends this blanked first image signal to the fade circuit (9). supply to.

The second reproduction signal obtained by the second head (Hl) is amplified by the second preamplifier (12) and then sent to the second demodulation circuit (
13) and is demodulated by the second synchronization separation circuit (14).
is supplied to The output of the demodulation circuit (13) is the second %
The first of the second switch (16) via the delay circuit (15)
It is supplied to the input terminal (16a) and the demodulation circuit (13
) is directly supplied to the second input terminal (16b). The synchronization signal obtained from the second synchronization separation circuit (14) is supplied to the second blanking pulse generation circuit (7), where a blanking pulse is generated and supplied to the second blanking circuit (18). This second blanking circuit (1
8) blanks the synchronizing signal of the image signal obtained from the output terminal (16c) of the second switch (16), and supplies this blanked second image signal to the fade circuit (9).

The fade circuit (9) sets the level of the input first image signal to (Vt) and the level of the second image signal to (V,
), and the output of the fade circuit (9) is (Vou[), then Vout= a V++ (1-a) Vt (
0≦a≦1)...■ In the equation (■), a fade effect is obtained by changing the coefficient a, and this output signal (Vout) is sent to the next-stage adder circuit (10) to the above-mentioned open and clear separation circuit ( 4) is added and supplied to a display device (not shown).

On the other hand, the first and second synchronization signals output from the first and second synchronization separation circuits (4) and (14) are respectively supplied to a phase comparison circuit (11), and as a result of the phase comparison therein, the phases match. If the phase does not match, it outputs an L (Low) signal, and if the phase does not match, it outputs an H (High) signal. The output of this phase comparison circuit (11) is supplied to one input terminal of an EX-OR (exclusive OR) circuit (19).

On the other hand, the PG pulse generation circuit (20) detects the leakage magnetic flux obtained from the PG yoke of the disk (1) and generates the PG pulse (A) shown in FIG. 2 (C)-A, thereby generating a field alternating signal. Supplied to the circuit (21). When the field alternating signal generation circuit (21) receives the PG pulse (A), it outputs the field alternating signal (B) shown in FIG. 19) and the first switch (6) as a control signal.

(1) When the output of the phase comparator circuit (19) is L, the operating waveform diagram in this case is as shown in Figure 2 (b), which is output from the EX-OR circuit (19) and supplied to the second switch (16). The signal (C) is in phase with the field alternating signal (B), and as a result, the first and second switches (6) (16)
are the same input terminal, that is, when the first switch (6) selects the first terminal (6a), the second switch (16) selects the first terminal (16a), and the first switch (6) selects the first terminal (16a).
selects the second terminal (6b), the second switch (16)
selects its second terminal (16b), and so on, the first and second switches (6) and (16) are switched in accordance with the input control signal (, L).

(2) When the output of the phase comparator circuit (11) is H, the operating waveform diagram in this case is as shown in Figure 2 (c), and the EX-OR circuit (
The signal (C) output from 19) and supplied to the second switch (16) is in opposite phase to the field alternating signal (B),
As a result, the first and second switches (6) and (16) have different input terminals, that is, for example, the signal of the second field is reproduced by the head (Hl), and the signal of the first field is reproduced by the head (Hj). When the first switch (6) selects its first terminal (6a), the second switch (16)
) selects its second terminal <16b), and the first switch (
6) selects its second terminal (6b), the second switch (16) selects its first terminal (16a), and so on, the first and second switches (6) and (16) are inputted. It switches according to the control signal HIL.

As described above, the first and second switches (6) (16
) is controlled so that the output terminals (6c) (16c) of the first and second switches (6) and (16) have the same continuity of the horizontal synchronizing signal and the skew distortion is corrected. This means that the first and second image signals are output.

(G) Effects of the Invention As described above, according to the present invention, special playback of fade-in and fade-out can be performed when switching from the previous screen to the next screen on the monitor screen without using large and expensive devices such as image memory. Thus, a magnetic disk reproducing device capable of performing the following operations can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a reproduction circuit of an electronic still camera embodying the present invention, and FIG. 2 is an operational waveform diagram thereof. (1)...Rotating magnetic disk, (H,)(H,)...
・First, second head, (3) (13)...first, second head
demodulation circuit, (1) (14)...first and second synchronization separation circuit, (5)(15)...first and second delay circuit, (6
)(16)...First and second switches, (9)...Fade circuit, (11)...Phase comparison circuit, (20)...
...PG pulse generation circuit, (21)...Field alternating signal generation circuit.

Claims (1)

[Claims] (1) a PG pulse generation circuit that detects the rotational phase of a rotating magnetic disk having a plurality of recording tracks and generates a PG pulse; a field alternation signal generation circuit that generates a field alternation signal in response to the PG pulse; a first head for obtaining a first field reproduction signal from one recording track of a rotating magnetic disk; a first demodulation circuit for demodulating the first field reproduction signal obtained by the first head; and a first demodulation circuit for demodulating the first field reproduction signal obtained by the first head. a first synchronization separation circuit that separates a first synchronization signal from a field reproduction signal; a first delay circuit that delays the output of the first demodulation circuit by 1/2H (horizontal scanning period); and the first demodulation circuit. a first switch means for selectively selecting and outputting the output of the first delay circuit and the output of the first delay circuit; and a second switch means for obtaining a second field reproduction signal adjacent to the one track of the rotating magnetic disk. a second demodulation circuit that demodulates a second field reproduction signal obtained by the second head; and a second synchronization separation circuit that separates a second synchronization signal from the second field reproduction signal. , a second delay circuit that delays the output of the second demodulation circuit by 1/2H, and a second switch that selectively selects and outputs the output of the second demodulation circuit and the output of the second delay circuit. means; a phase comparison circuit for detecting coincidence/mismatch in phase between the first synchronization signal and the second synchronization signal; receiving image signals output from each of the first and second switch means;
and a fade circuit that performs a fade operation based on these image signals, and the first and second switch means are configured to synchronize with the field alternating signal so that the phases of the output image signals of the first and second switch means match. A magnetic disk reproducing device characterized in that it is controlled by an output signal of the phase comparator circuit.