KR910000202Y1 - Recording signal divide erase head of vtr - Google Patents

Abstract

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Description

Recording signal separation erasing head of video recorder

1 is a schematic diagram of a tape running system of a video recorder.

2 is a conventional Full Erase Head.

3 is a recording signal separation erasing head according to the present invention.

4 is a video dubbing circuit diagram according to the present invention.

5 is an operating waveform diagram of FIG.

6 is a video dubbing flowchart of FIG.

* Explanation of symbols for main parts of the drawings

110: microcomputer 120: oscillation circuit

130: video recording circuit 140: recording signal separation erasing head

150: Video head SW1-SW3: Function selector switch

The present invention relates to an erasing head of an image recording and reproducing apparatus, and more particularly to a recording signal separation erasing head capable of separating and erasing an audio signal and an image signal recorded on a magnetic tape for an image recording and reproducing apparatus.

Typically, the tape traveling system of the video recorder is as shown in FIG.

The configuration diagram of the drive mechanism employed in the general video recording and reproducing apparatus VTR, which is the configuration shown in FIG. 1, shows a state in which magnetic tape is loaded in the drum 6.

After immersion in the figure, SUP and TAK represent a supply tape (SUP) and take up reel (TAK) of a cassette tape or a reel tape.

Reference numeral 1 denotes a tension pole for adjusting the tension of the tape when the take-up reel TAK winds the tape by mechanical operation. Reference numeral 2 denotes a circular roller, 3 denotes a full erase head for erasing information recorded on the full width of the tape, and 4 and 8 denote first and second guide poles. , 5 and 7 are the slant poles. 6 is a drum equipped with a video recording / playback head, 9 is an impedance roller, 10 and 11 are an audio muting head, an erasing head and an audio control head, 12 is a third guide pull, and 14 is a rotation of a capstan motor. The capstan shaft is rotated by (Capstan Shaft), 13 is a pinch roller (Pinch Roller) for pressing the tape to the capstan motor shaft 14 to drive the tape by the rotation of the shaft (14).

Therefore, the tape traveling system configured as described above is rotated by the motor when the reel TAK is rotated in the winding direction while the pinch roller 13 is pressed against the capstan shaft 14 which rotates the tape. The tape wrapped in the drum runs.

That is, the tape also travels at a constant speed by the constant speed driving of the capstan motor and the motor for rotating the reel to reel.

Supply reel (SUP) → full width head (3) → head drum (6) → audio head (10) → audio control head (11) → capstan motor shaft (14) → winding reel (TAK) A conventional method for dubbing a video signal in a video recording player having a traveling system configured as 1 degree is a full width erasing head (3) which receives an electric control signal and generates an erasing magnetic field signal. After the signal has been fully erased, a video signal input from the outside has been recorded into the video head mounted on the drum 6.

The full width erasing head 3 shown in the tape traveling system of FIG. 1 is a full width erasing head FEH having the same width as that of the magnetic tape in the shield case 15 as shown in FIG. (Full Erase Head) is built-in, the gap (17) surface of the full width erased head (FEH) is formed on one surface of the shield case 15, the shield case 15 is a bracket (Bracket) It is attached to (16) and is comprised.

At this time, the full-width erasing head (FEH) embedded in the shield case 15 of FIG. 2 is an iron core (or core) in which a gap 17 is formed and a winding coil wound thereon, as is widely known in the head art. It consists of.

The full width A of the conventional full width erasing head FEH as described above has a length of 12.65 mm equal to the width of the standard video magnetic tape.

Therefore, when the gap 17 surface of the full width erasing head 3 having the structure as shown in FIG. 2 is in contact with the width (12.65 mm) of the magnetic surface of the magnetic tape, when recording the video signal even if only the video signal is dubbed For example, an audio signal and a video signal are all erased by a signal written in a tape width (12.65 mm) by the full width erasing head 3 generating an erasing magnetic field in response to an erase bias (normally alternating signal) generated. Has been.

In other words, in order to dub only the video signal, the audio signal should be erased and recorded while leaving the audio signal intact. However, in the conventional full-width erasing head, when only the video signal is recorded by erasing all the audio and video signals recorded on the magnetic tape. The audio signal must be recorded after being transferred to a separate tape recorder or other recording medium for preservation.

Accordingly, an object of the present invention is to provide a recording signal separation erasing head capable of separating and erasing a video signal and an audio signal separately recorded on a predetermined area of a full width of a standard video signal recording tape.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a recording signal separation erasing head according to the present invention, and an audio erasing head (AEH) is set on the upper side, and the video erasing head of the standard video recording / reproducing tape format is set on the lower side. (Video Erase Head) VEH is set, and the guide area AVG of the audio-video erasing head is set between the audio erasing head AVH and the video erasing head AEH.

The audio erasing head AEH and the video erasing head VEH are embedded in one shield case 15, and the gap of the video erasing head VEH and the gap of the audio erasing head AEH are magnetic tapes. It is formed on one surface of the shield case 15 to be in contact with the magnetic surface of the. In this case, each of the video erasing head VEH and the audio erasing head AEH is formed by winding a winding around an iron core having voids formed therein.

The width of the audio erasing head AEH is equal to the width of the audio track of the standard video signal recording / playback tape format, and the width of the video erasing head VEH is the tape width of the standard video signal recording / playback method. It is set to have a width of 11.50 mm minus 1.15 mm, which is the sum of the width of the audio erasing head 1 mm and the width of the guide region of the audio-video erasing head 0.15 mm at 65 mm.

The audio track in the magnetic tape supplied from the supply reel SUP is mounted at the same position as that of the full-width erasing head 3 of the traveling system of the tape shown in FIG. The audio signal and the video signal respectively recorded in the video and full widths can be separately erased.

4 is a circuit diagram for video dubbing according to the present invention, and is a circuit using the recording signal separation erasing head of FIG. 3 according to the present invention.

The configuration is provided by inputting signals by pressing the selection keys SW1-SW3 and pressing the selection keys SW1-SW3 for inputting still, reset, and video dubbing signals of the video recording and reproducing signals by pressing the keys. The microcomputer 110 determines an operation state and outputs a video erasing control signal VEO and a video dubbing control signal VDO when the video dubbing key signal is input in the still mode, and the video erasing output from the microcomputer 110. The oscillation circuit 120 oscillates and outputs an AC bias for erasing the magnetically recorded video signal in response to the output of the control signal VEO, and the magnetic surface of the traveling magnetic tape is in contact with the oscillation circuit 120. The recording signal separation erasing head 140 generates an erasing itself by the oscillation output bias signal and separates only the video signal recorded in the video width of the tape width, and a video signal input terminal. And a video outputting a video recording signal (VRS) by converting the video signal input to the terminal into a frequency of a recording signal band by a video dubbing control signal (VDO) output from the microcomputer 110. The recording circuit 130 and the video head 150 for recording the recording video signal VRS output from the video recording circuit 140 in the video width of the magnetic tape.

5 is an operation waveform diagram of FIG. 4, (a) shows a video signal dubbing start point (a) and a dubbing end point (d) on a magnetic tape, and the video signal dubbing start point (a) and the dubbing end point (d) The section (b) is dubbed. At this time, the dubbing end point d is a point at which the counter is reset.

(b) shows an output waveform of the video dubbing control signal VDO of the microcomputer 110.

(c) is an output of the video erasing control signal VEO of the microcomputer 110, and is removed before the video dubbing end point d by a time t.

6A and 6B are an operation flowchart of FIG. 4 during video dubbing, and FIG. 6A is a check for resetting to a counter that counts driving of a magnetic tape when a video dubbing key is input in a still mode. A flowchart for controlling the output of the video cancellation control signal and the video dubbing control signal.

6B is a reset subroutine of FIG. 6A.

Hereinafter, an example of dubbing the video signal after erasing only the video signal among the recording signals of the magnetic tape on which the video signal and the audio signal are recorded using the recording signal separation erasing head according to the present invention will be described with reference to the above-described drawings.

Now, the user finds a dubbing out point (Dubing end point) d, which is the last part of the screen, which is dubbed and deteriorated in the magnetic tape area as shown in FIG. 5A where the video program and the audio signal of the video program are recorded. Next, when the reset key SW2 of FIG. 4 is pressed, the power supply voltage Vcc through the resistor R1 is input to the microcomputer 110. At this time, the microcomputer 110 reads the key input port for a predetermined scan period to detect the pressing state of the still key SW1, the reset key SW2, the video duplexer SW3, and other keys (not shown). It becomes aware.

The microcomputer 110 recognizing that the reset key SW2 is pressed resets the counter that counts the running of the tape. That is, the last part (Dubbing out point) of the lower surface to be dubbed to the microcomputer 110 is stored.

After setting the portion of the screen to be dubbed from the magnetic tape of FIG. 5a as described above, rewind the magnetic tape, and then use the frame advance (not shown) or the still key (SW1) of FIG. ) To find the dubbing in point (dubbing point) of Figure 5a correctly and set the operation mode to still mode. At this time, the tape counter reset at the dubbing end point d of FIG. 5A is counted when the tape is run in the rewind direction, and counted up when the tape is run in the forward direction.

Accordingly, if the tape is rewound to the dubbing start point a after resetting the counter at the dubbing end point d of FIG. 5a, the counter is counted down to the dubbing start point in the reset state.

When the video dubbing stant key SW3 is pressed in the still mode in which the dubbing end point and the derby start point are set as described above, this is recognized by the microcomputer 110 by an operation of scanning a key terminal at a predetermined period. .

The microcomputer 110 which inputs the video dubbing signal by pressing the video dubbing SW3 checks the reset by the program of FIG. 6A.

At this time, the reset check of FIG. 6a is checked by the microcomputer 110 in the same order as that of FIG. 6b.

[Fig. 6B is a subroutine of the reset check routine of Fig. 6A.] The microcomputer 110, which starts the reset check, first checks whether the built-in counter is reset, and if so, resets the driving mode of the magnetic tape. To judge.

In the above driving mode, it is determined whether the driving speed of the tape is SP (Standdrd Play), LP (Long Play), or SLP (Super Long Play) mode.

When the running mode of the tape is broken by the above operation process, the microcomputer 110 performs the calculation according to the following equation (1), and the tape length ℓ between the recording signal separation erasing head and the rotary head (see the tape running system of FIG. 1). Obtain the time for not collecting the video signal recorded in the).

ℓ: distance from the erasing head to the rotary head (video head) v: speed of the tape according to the driving mode ℓ in the equation (1), ℓ has a fixed value as a non-zero constant, and v is the SP at the speed of the tape. A nonzero constant that varies with, LP, SLP. Accordingly, the calculation value according to the equation (1) is changed according to three tape traveling speeds SP, LP, and SLP, and the microcomputer 110 having calculated the equation (1) according to the driving mode is determined by the reset count value. Count down the operation value according to equation (1) and store the value together with the counter reset data in the internal memory.

For example, if the reset value of the counter is øøøøø ₍₁₀₎ and the calculated value of equation (1) different from the driving mode is 10 ₍₁₀₎ , the microcomputer 110 generates the calculated value 0010 ₍₁₀ from the reset value øøøøø. _{In the} internal memory, the 0090 ₍₁₀₎ data _{, which} has down counted ₎ , the counter data, and the counter reset value øøøøø ₍₁₀₎ are stored.

When the driving speed of the tape is determined as described above, and the data in which the operation value according to the determined driving mode is down counted in the counter reset data is stored in the memory, the microcomputer 110 disconnects the output lines 15 and 190. The video erase control (VEO) and the video dubbing control signal (VDO) as shown in FIG. 5B and (c) are simultaneously output.

The oscillation circuit 120 for inputting the video erasing control signal VEO output as shown in FIG. 5b from the microcomputer 110 operating according to the levels of FIGS. 6a and 6b oscillates an erasing bias signal and thus lines 160. The output signal is output to the video erasing head VEH of the recording signal separation erasing head 140 described above with reference to FIG.

The video erase head VEH in the write signal separation erase head 140 inputting the erase bias signal generated by the oscillation circuit 120 generates an erase magnetic field according to the erase bias and is supplied from the supply reel SUP. Only video signals recorded on the video full width of the magnetic tape are erased.

On the other hand, the video recording circuit 130 inputs the video dubbing control signal VDO output from the microcomputer 110 as shown in FIG. 5C. The video recording circuit 130 receives the video signal (usually a composite video signal) input to the external video signal input terminal 100. A video head 150 is output as a signal of a recording signal band frequency of a magnetic tape, which is used as a dubbing signal. Accordingly, the video head 150 records the dubbing signal on the contact surface of the video full width supplied from the supply reel SUP and erased by the video erasing head VEH.

As described above, the microcomputer 110 outputting the video erasing control signal VEO and the video dubbing control signal VDO is a counter for counting up the running of the tape from the dubbing start point a of FIG. 5a by the operation of FIG. 6a. The data value reaches the data value set in the internal memory by the process of FIG. 6B (counter reset-α, where α value is the value X, Y, Z calculated by Equation (1) according to the traveling speed mode). Determine the search. If the current counter value is equal to the down counted value in the counter reset data in the search determination, the microcomputer 110 maintains the "high" state as shown in FIG. 5C. The output of the video erasing control signal VEO is stopped, and the video dubbing control signal VDO is kept in a "high" state as shown in FIG. 5B.

The video dubbing control signal VDO is also set to " low " as shown in FIG. Stop dubbing.

In the operation example of the present invention, only the oscillation circuit 120 for providing an erasing bias to the video erasing head VEH has been described to explain the process of erasing and recording an image signal. A voice signal processing circuit for oscillating the erasing bias of the erasing head AEH and a voice signal processing circuit for modulating an external audio signal for recording audio signals is erased so that only the audio signals recorded on the magnetic tape of the video recorder can be erased. It should be noted that this can be done.

As described above, the present invention allows video recording and playback to be separately erased from the audio signal recorded on the magnetic tape and the video signal so that video editing can be freely performed regardless of the audio signal recorded on the same recording surface during dubbing recording of the video signal. There is an advantage to this.

Claims (2)

An erasing head of a video recording / reproducing apparatus for recording and reproducing video signals and audio signals with different areas on one recording surface of a magnetic tape, the audio erasing unit for erasing audio signals recorded by separating areas on one recording surface of the magnetic tape. A video erasing head (AEH) having a head (AEH) and a video erasing head (EEH) for erasing a video signal recorded by dividing an area on one recording surface of the magnetic tape is provided below the audio erasing head (AEH). And a guide area (AVG) of an audio-video erasing head (AEH) (V degrees) is set between (AEH) and video erasing head (AEH). The standard video signal recording / reproducing method of the video erasing head (AEH) according to claim 1, wherein the width of the audio erasing head (AEH) has a width equal to that of the audio track of the standard video signal recording / reproducing tape format. And a width of 11.50 mm minus 1.15 mm of the width of the audio erasing head width 1mm and the sum of the width of the guide area of the audio-video head 0.15 mm from the tape width of 12.65 mm.