KR950005042B1 - Changing speed playing method and system of vcr - Google Patents

Abstract

A speed variable reproducing method of video cassette recorder performing a reproducing operation repeatingly at a normal speed or a varied speed, includes: a first step of detecting an (i)th recording data and (1+n)th recording data by using a head and an auxiliary head in case of a normal driving operation; and a second step of outputting the signal detected in a main head during the normal speed driving, and outputting the signal detected from the auxiliary head during the vared speed driving.

Description

VCD variable speed regeneration method and apparatus therefor

1 is a block diagram of a variable speed regeneration device of the VR of the present invention.

2 is an exemplary view showing a structure of a head according to the present invention.

3 is an exemplary diagram showing a tape running speed according to a section, (b) is an exemplary diagram showing a tape pattern that the head travels, and (c) a waveform diagram of a traveling speed according to tape shift playback.

4 is an exemplary view showing a reproduction state of data in FIG.

FIG. 5 is an exemplary diagram showing the state of reproduction data over time in FIG.

6 is a waveform diagram of each part in tape shift reproduction in FIG.

* Explanation of symbols for main parts of the drawings

1: Head Drum 2A, 2B: Record & Reproduction Amplifier

3A, 3B: Digital Signal Processor 4A, 4B: Picture Memory

5: memory control unit 6: data switching unit

7 controller 8 signal synthesis section

9: capstan 10: pinch roller

SW1-SW3: Switch HA1, HA2, HB1, HB2: Head

The present invention relates to the variable speed reproduction of V-Cal. In particular, in the variable speed reproduction of the digital reproduction mode, the constant speed reproduction and the acceleration / deceleration skip operation are repeated, and two sets of heads simultaneously perform two arbitrary frames in the constant speed period. The present invention relates to a variable speed reproduction method of a digital VR to be reproduced, and an apparatus thereof.

In general, V-Cal performs a fast shift playback, and as the traveling speed of the tape accelerates more than the normal playback speed, the linear trajectory of the head relative to the tape is changed, and thus the recording pattern is detected by traveling across several tracks. That is, when the variable speed reproduction is performed, the area read in one track becomes small in inverse proportion to the double speed of tape travel, so that only a part of the recording pattern is detected. Accordingly, V-Cal reproduces the image on the screen by combining a part of the image signal detected in each track.

However, in the analogue method, the analog signal can reproduce the video signal by combining a part of the detected signal in each track in the analog method, but in the digital method, the video signal and the audio signal are combined and converted into digital data and the signal pressure measurement is performed. By recording onto a tape, data of which only a part of each track is detected at the time of shift reproduction cannot be restored, or an image completely different from the original image can be obtained. In particular, during shift playback, the head travels across several tracks to partially detect recorded video signals, and at the same time, signals with different azimuth angles between the heads and tracks are detected as noise, and the reproduced images are distorted. There was a problem breaking.

In order to solve this problem, the present invention has a predetermined phase angle with a digital head and at the same time, an auxiliary head having a predetermined step is mounted on a drum and separated from the track by a predetermined phase angle in any track and at the time of shift reproduction of the digital signal. Simultaneously detects tracks at constant speed, stores them in image memory, accelerates and decelerates, moves to any next track, detects tracks moved at constant speed, switches the stored data, and repeats the operation of synthesizing the switched signals. The present invention has been made of a variable speed reproduction method and apparatus for reproducing an image of a digital VR, which will be described in detail with reference to the accompanying drawings.

According to the present invention, the variable speed regeneration method of V-Cal is used to detect the i-th frame data and the i + n-th frame data simultaneously during the constant speed period as two sets of heads through the constant speed, acceleration and deceleration of the tape drive, and output the i-th data in the constant speed period. The i + n-th data performs an operation of outputting in the acceleration and deceleration periods of the tape, and by repeating such an operation, arbitrary frames are sequentially detected to reproduce an image signal.

FIG. 1 is a block diagram of the variable speed regeneration device of the present invention V-Cal. As shown in FIG. 1, the head is formed from a tape that is compressed and conveyed between the capstan 9 and the punch roller 10 according to the rotation of the capstan motor M1. the switching signal of the HA1), (HA2), ( HB1), the switch (SW1) (SW2), a switch (SW1) (SW2) to (HB2) is respectively switched to detect a recording signal (V ₁ ~ V ₄₎ Recording and reproducing amplifiers 2A and 2B for respectively amplifying a predetermined level, digital signal processors 3A and 3B for demodulating and converting the output of the recording and reproducing amplifiers 2A and 2B into digital data; Image memories 4A and 4B for storing output data of the digital signal processor 3A and 3B, memory controller 5 for controlling data storage and output of the image memories 4A and 4B, the image memory (4A), (4B) the output (V ~ ₅ V ₆₎ and the data switch (SW3) for selecting under the control of the switching unit 6, the signal switch (SW3) is selected in And a signal synthesizing unit 8 for synthesizing and restoring the digital data V, and a controller 7 for controlling each switch and each control unit. The main heads HA1 and HA2 are shown in FIG. As described above, the auxiliary head HB1 is mounted on the head drum 1 with a phase angle of 180 ° and has a predetermined step H while the main header HA1 and HA2 have an arbitrary phase 1θ. (HB2) is mounted to the head drum (1).

The operation and effects of the present invention configured as described above will be described in detail with reference to FIGS. 3 to 6 as follows.

When the variable speed reproduction mode is selected to shift and reproduce the digital video signal recorded on the tape, the tape compressed between the capstan 9 and the pinch roller 10 by the rotation of the capstan motor M1 under the control of the controller 7 Is repeatedly transferred to the constant speed, acceleration and deceleration operation for a predetermined time, and the drum motor (not shown) rotates the head drum 1 at a speed of 3600 rpm.

At this time, the signal recorded on the conveyed tape is controlled by the controller 7 and the head drum 1 is rotated and the heads HA1, HA2, HB1 (in accordance with the switching of the switches SW1, SW2) ( The signal V ₁ to V ₄ detected by the heads HA1, HA2, HB1, and HB2 are switched by the control of the controller 7 and are switched by the switch SW1 (SW2). Is sequentially outputted to the recording / reproducing amplifiers 2A and 2B by sequentially connecting the contacts c1 and c2 to the contacts a1 and b1 (a2 and b2).

That is, the main head HA1 HA2 of the channel CH1 is switched by the head switching signal HSW _{1 as} shown in FIG. 6A, and the head as shown in FIG. 6B. As the auxiliary heads HB1 and HB2 of the channel CH2 are switched by the switching signal HSW ₂ , the recording signals of the i th and i + n th frames are simultaneously detected on the tape conveyed at constant speed. The contacts a1 and c1 (b2 and c2) of the switches SW1 and SW2 are connected to the head HA1 and HB1 by the head switching signals HSW ₁ and HSW _{2 as} shown in FIG. By reading the signal V ₁ (V ₃ ) as shown in FIG. 6 (c) (e), the contacts a1, c1 (b2, c2) of the switches SW1 and SW2 are connected to the head HA2. The signal V ₂ (V ₄ ) as shown in FIG. 6 (d) (f) is read by (HB2).

The above-described operation will be described with reference to FIG. 3 again. When the head HA1 travels the mantissa track of the i-th frame, the head HB1 travels the nose track of the i + n-th frame. After that, the head HA2 runs on the even track of the i-th frame and the head HB2 runs on the even track of the i + n-th frame.

At this time, as the outputs V ₁ and V ₂ (V ₃ and V ₄ ) of the heads HA1, HA2, HB1 and HB2 are input, the recording / reproducing amplifiers 2A and 2B amplify to a predetermined level. Outputting the signal to the digital signal processor 3A (3B) restores the original digital data by demodulating the modulated signal and storing the digital data in the image memory 4A (4B) under the control of the memory control section 5. It is done.

At the time when the constant speed travel is completed, the tape is transferred to the next frame at high speed by the tape acceleration reference signal VS _{1 as} shown in FIG. 6 (car), and also shown in FIG. By the tape deceleration reference signal VS ₂ as described above, the tape is slowly transferred at low speed to connect the position of the head to the next frame. That is, when a recording signal is detected in any two frames of the tape through the constant speed operation, the capstan motor M1 accelerates and rotates and then decelerates and rotates the position of the main head HA1 under the control of the controller 7. The second Hn1 frame is connected, and the position of the head HB1 is connected to the i + 3nth frame.

Accordingly, the acceleration / deceleration mode is activated after the recording signals of the i + nth and i + nth tracks are simultaneously detected at constant speed by the heads HA1, HA2, HB1, and HB2 of the channels CH1 and CH2. When the noise detected in the acceleration / deceleration section of the stored data of the image memories 4A and 4B is removed by the control of the memory controller 5, the data is switched by the data switching unit 6 under the control of the controller 7. SW3 alternately selects the outputs V ₅ and V _{6 of} the image memories 4A and 4B as shown in FIG. 6 (h) and outputs them to the signal synthesizing section 8. Done.

Accordingly, the signal synthesizing unit 8 receiving the signal output from the switch SW3 sequentially synthesizes the input image signal to reproduce the output signal V ₀ on the screen as shown in FIG. Done.

After the signal detected by the tape is reproduced, the i + 2n-th and i + 3n-th frame are reproduced at a constant speed by the control of the control unit 7. As the above operation is repeated, the recording signal of the tape is detected at a predetermined interval. Lose. Accordingly, the outputs of the respective heads HA1, HA2, HB1, and HB2 are as shown in FIGS.

As a result of performing this shift regeneration operation, when one cycle of the head switching signal is completed, the data acceleration reference signal VS ₁ is enabled as shown in FIG. 6 (car) within a predetermined time Δt, thereby accelerating tape travel. When the tape deceleration reference signal VS ₂ is enabled as shown in FIG. 6 (C) again, the tape travel is decelerated, and the constant speed travel is performed again after a predetermined time Δt. That is, the running speed of the tape is repeatedly performed at constant speed, acceleration and deceleration between the constant levels Vo-nVo as shown in FIG.

Therefore, as the signals V ₁ to V _{4 as} shown in FIGS. 6C to 6B are detected, the signals V ₅ and V _{6 as} shown in FIG. The signal V ₀ output from 4A) 4B and shown in FIG. 6 (i) under the control of the data switching section 6 is reproduced on the screen.

In addition, the time difference Δt ₁ included in the head switching signal of FIG. 6A ( _b ) is such that the auxiliary heads HB1 and HB2 are located at the mounting positions of the mechanical heads rather than the main heads HA1 and HA2. This is caused because there is a phase difference by an arbitrary angle (1θ). In addition, the delay of the acceleration section Δt ₂ and the reduction of the deceleration section Δt ₃ after the constant speed of the tape causes the tape transition movement section generated by the inertia of the capstan motor to be in the acceleration and deceleration section. It is the intentional delay and shortening to precisely control the position of the tape.

Comparing the tape running speed at the time of the speed change reproduction and the conventional tape running speed at the time the speed change reproduction according to the present invention in FIG. 3 (a), conventionally, a constant speed for a time that is 2Δt to travel by a predetermined distance (2nlo) at n times speed is known. Although nlo / Δt and in the present invention, lo / Δt in the constant speed section and (n-1) lo / Δt in the acceleration / deceleration section, the mileage of the tape within the predetermined time 2Δt is the same as 2nlo, which shows the same double speed effect.

4 is an exemplary view showing the reproduction state of data, in which one stream of data is reproduced by track reproduction of the i-th frame of the heads HA1 and HA2, and the i + nth frame by the auxiliary heads HB1 and HB2. Tracks are played and data of one stream is played. By repeating this operation, the tape is played back as shown in Fig. 4B.

5 is a diagram schematically showing the state of data read by each head for each channel. Effective data detected by head switching is detected for each section as the tape is constant speed, acceleration and deceleration. That is, the recording signal of the tape is detected every predetermined time (2Δt) time as the constant speed travel for a predetermined time (Δt) and the acceleration and deceleration run for a predetermined time (Δt).

In this case, the tape travels at a constant speed as shown in FIG. 3 (a) at constant speed and (nl) lo / deceleration travels at a distance of lo. The detection pattern of the tape is shown in FIG. As shown.

Accordingly, the reproduction state of the signal detected on the tape is as shown in FIG.

As described in detail above, in the present invention, when two sets of heads, which are the main head and the auxiliary head, are mounted on a drum and the variable speed reproduction is performed in the digital mode, the recording of any two tracks is repeated by repeating the tape feeding at constant speed, acceleration, and deceleration. The signals are detected simultaneously, and only the signals detected in the constant speed section of the detected signals are reproduced and synthesized in the acceleration and deceleration sections. Accordingly, in the present invention, by removing the noise signal detected in the acceleration and deceleration periods during the reproduction of the detected signal, there is an effect of reproducing a clear screen free from distortion and noise.

Claims (3)

In the variable speed reproduction method of V-CAL, which reproduces while repeating the constant speed and the shift speed, the first step of detecting the (i) th and (i + n) th recording data using the main head and the auxiliary head during the constant speed driving. And a second step of outputting the signal detected by the main head when driving at constant speed, and outputting the signal detected by the auxiliary head when driving at variable speed. The recording signals V ₁ and V ₂ detected by the heads HA1, HA2 and HB1 and HB2 on the tapes which are compressed and conveyed between the capstan 9 and the pinch roller 10 as the capstan motor M1 rotates. ), (V _3, the switch (SW1) (SW2), a switch (SW1) (recording and reproducing amplifier (2A) (2B) for amplifying the switching signal SW2) to the respective predetermined level for each switch the V ₄₎ and A digital signal processor (3A) (3B) for demodulating the output of the recording / reproducing amplifier (2A) (2B) and converting it into digital data; and an image for storing output data of the digital signal processor (3A) (3B). Memory 4A, 4B, a memory controller 5 for controlling the data storage and output of the image memory 4A, 4B, and an output V ₅ (V) of the image memory 4A, 4B. and ₆₎ the data and a switch (SW3) for selecting under the control of the switching unit (6), the switch (SW3) a signal synthesis section 8 synthesizes the selected signal to restore it to digital data (V _0), the Each switch And shifting the reproducing apparatus of the digital V CR, characterized in that consists of a controller 7 for controlling the respective control unit. 3. The head drum (1) according to claim 2, wherein the head drum (1) has an arbitrary angle (θ) on the main head (HA1) (HA2) having an opposing angle of 180 degrees, and an auxiliary head (HB1) having a step (H) ( HB2) is mounted and configured, the variable speed playback device of the digital V-Cal.