JPS639003A - Rotary head type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To shorten the diameter of a rotary cylinder by compressing and recording the time axis of an input signal in accordance with the rotation of the rotary cylinder and extending and reproducing the time axis of an output signal. CONSTITUTION:A video signal converted by a photographing element 50 is converted into 5/6 time by a control signal outputted from a signal processing circuit 51 every time of one field. A sound signal applied to an input terminal 68 is also compressed to 5/6 at its time axis by compressors 70, 71 synchronously with the rotation of the rotary cylinder on the basis of a signal outputted from a control device 62 and applied to magnetic heads 57a, 57b, 76a, 76b fitted to the rotary cylinder 56 to be rotated by one revolution at a field period by a motor 61 and a control device 62 through a modulator 72, an amplifier 73, a switch, a transformer and so on. In a reproducing process, the video signal and the sound signal are returned to normal signals by time extenders 66, 79, 80 and outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary head type magnetic recording and reproducing device for magnetic recording and reproducing devices.

BACKGROUND OF THE INVENTION In recent years, the audio reproduction performance of video tape recorders has improved, and they are now being used for music reproduction under the name hi-fi video.

An example of the conventional no-ify video mentioned above will be described below with reference to the drawings.

FIG. 3 shows a block diagram of a conventional high-fidelity video recording and reproducing section. In FIG. 3, Mi1 is a first input terminal into which an audio signal is input, 2 is a first amplifier that amplifies the audio signal, 3 is a first modulator that performs frequency modulation, and 4
amplifies the output signal of the first modulator 3 and transmits the rotating cylinder 7
A second amplifier supplies current to the first magnetic head group 8& and 8b attached to the , 6 is a first switch that is switched during recording and reproduction, 6 is a first rotary transformer, 9 is the direction of the arrow M 10 is a third amplifier that amplifies the signals reproduced by the magnetic heads 81L and 8b, 11 is a first demodulator that demodulates the frequency, and 12 is a fourth amplifier that amplifies the demodulated output. , 13 is the first output terminal, 1
4 is the second input terminal into which the video signal is input, 16 is the first input terminal.
16 is a second modulator that performs frequency modulation; 17 is a signal processing circuit that amplifies the output signal of the second modulator 16; and a second magnetic head group 20aL attached to the rotating cylinder 7.
and 20b, 18 is a second switch that is switched during recording and reproduction, 19 is a second rotary transformer, and 21 is a magnetic head 20! A sixth amplifier amplifies the signal reproduced by L and 20b, a second demodulator 22 demodulates the frequency, and a second signal processing circuit 23 converts the output signal of the second demodulator 22 into a video signal. , 24 is a second output terminal to which a video signal is output.

Regarding the No Ifai video configured as above,
The operation will be explained below.

The audio signal input to the first input terminal 1 is amplified by the first amplifier 2, and then applied to the first modulator 3.
A frequency modulated wave, which is an output signal of the modulator 3 that frequency modulates a carrier having a frequency of less than Hz, is amplified by the second amplifier 4, and then passed through the first switch 6, which is switched to the R side.
and the rotating cylinder 7 via the first rotating transformer 6t-
It is added to the magnetic heads 81L and 8b attached to the magnetic heads 81L and 8b.

On the other hand, the video signal applied to the second input terminal 14 is separated into a luminance signal and a color signal by the first signal processing circuit 15 and applied to the second modulator 16.

The second modulator 16 outputs a mixed signal of the frequency modulated wave, the rounded luminance signal, and the low frequency converted color signal, and is added to the sixth amplifier 17. The output signal of the fifth amplifier 17 is applied to the magnetic heads 201L and 20b via the second switch 18 switched to the R side and the second rotary transformer 19. A magnetic tape 9 is wrapped around the rotating cylinder 7 at an angle slightly larger than 180 degrees as it travels in the direction of the arrow.Since the rotating cylinder 7 rotates half a turn for one field of the video signal, the magnetic tape 9 is wrapped around it at an angle slightly larger than 180 degrees. The tracks are oblique to the running direction of the magnetic tape, and signals for one field are recorded. FIG. 4 shows a conceptual diagram of tracks recorded in this manner. As shown in FIG. 4, the track 261L recorded by the magnetic head 8 & on the magnetic tape 9 is
magnetic head 81L+8b, 20a such that track 25b recorded by magnetic head 8b is covered by track 26N recorded by magnetic head 20&.

The position and height of the attachment of 20b to the rotating cylinder 7 are determined. The tracks recorded in this way overlap, but the azimuth angle of the head gap of the magnetic head 8a is set to +30 degrees, the azimuth angle of the head gap of the magnetic head 20b is set to +30 degrees, and the azimuth angle of the head gap of the magnetic head 8b is set to +30 degrees. Since the azimuth angle of the Rad gap is set to 130 degrees and the azimuth angle of the Rad gap of the magnetic head 201L is set to +6 degrees, it is possible to reproduce the data separately. This utilizes an effect called azimuth loss.

Next, the playback operation will be described. The rotation of the rotary cylinder 7 and the running of the magnetic tape 9 are controlled so that the magnetic head runs along the tracks recorded on the magnetic tape 9. In this way, the frequency modulated wave modulated by the audio signal reproduced by the magnetic heads 8a and 8b is transmitted to the first rotary transformer 6 and the first switch 6 switched to the P side.
and is added to the third amplifier 10. The output signal of the third amplifier 10 is applied to the second demodulator 11 and frequency demodulated to demodulate the audio signal at the time of recording. The audio signal thus obtained is amplified by the fourth amplifier 12 and then output to the first output terminal 13.

On the other hand, the luminance signal in the form of a frequency modulated wave and the low-frequency converted color signal reproduced by the magnetic heads 20a and 20b are transferred to the second rotary transformer 19 and the second switch 18 switched to the P side. After being amplified by the sixth amplifier 21, it is applied to the second demodulator 22. A luminance signal and a color signal before conversion are obtained from the second demodulator 22, and these signals are returned to the original video signal by the second signal processing circuit 23. The video signal at the time of recording is output to the second output terminal 24.

In this way, audio and video signals are recorded and played back, and because the audio signals are recorded using frequency modulation, the quality of the played back audio is good, which is why it is called high-fidelity video.

Problems to be Solved by the Invention However, in the above configuration, the diameter of the rotating cylinder is large, making it difficult to downsize the device.

For example, in the case of the VHS format, the diameter of the rotating cylinder is 62 cm, which is a particular problem in the Votapul device.

In view of the above-mentioned problems, the present invention provides a rotary head type magnetic recording and reproducing device having a high-fidelity video function by reducing the diameter of a rotating cylinder. Therefore, the rotating head type magnetic recording/reproducing device of the present invention includes two time base compressors, two recording amplifiers, at least two pairs of magnetic heads attached to a rotating cylinder, and controlling the rotation of the rotating cylinder. a tape running control device for winding the ζ magnetic tape around a rotating cylinder at an angle of 180 degrees or more and running it;
It is equipped with two reproduction amplifiers and two time axis expanders.

According to the present invention, with the above-described configuration, signals can be recorded with a rotating cylinder that rotates once per field period of the video signal to be recorded, so that all the rotating cylinders with small diameters can be used. In addition, since the time axis of the input audio and video signals is compressed in accordance with the rotation of the rotating cylinder and recorded on the magnetic tape, the recording state is unchanged from that of the magnetic tape recorded with conventional high-fidelity video, and playback is possible. Sometimes tapes are compatible. In other words, all the functions of conventional high-fidelity video can be realized with a miniaturized device.

EXAMPLE Hereinafter, a rotary head type magnetic recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of a rotary head type magnetic recording/reproducing apparatus according to the present invention.

In FIG. 1, 5o is an image sensor that converts an image taken by a video camera into an electric signal, and 51 is an image sensor that converts the electric signal into a video signal while controlling the speed at which the image sensor 50 converts the image into an electric signal. 1 signal processing circuit, 62 a first modulator that modulates the video signal output from the first signal processing circuit 51, 53 amplifies the output signal of the first modulator 52, and is attached to the rotating cylinder 66. 64.74 are first and second switches that are switched during recording and reproduction; 56.75 are first and second rotation switches; Trance,
58 and 59 connect the magnetic tape 60 to the rotary cylinder 56.
A guide pin for winding the magnetic tape diagonally at an angle slightly larger than 0 degrees and running the entire magnetic tape 60 in the direction of the arrow.
61 is a motor that rotates the rotating cylinder 56; 62 is a leg restraint device that controls the rotation of the motor 61 and the time axis of the signal; 63 is a second amplifier that amplifies the signal reproduced by the magnetic heads 57a and 57b; 84 and 78 are first and second demodulators, 66 is a second signal processing circuit that converts the demodulated output of the demodulator 64 into a video signal, and 66 is a circuit that allows the time axis of the video signal to be viewed on a general television. 67 is a first output terminal to which a video signal is output; 68 is an input terminal to which an audio signal is input; 69
is the third amplifier, To and 71 are the bucket-prigate-
A compressor for compressing the time axis, which is composed of a device (hereinafter referred to as BBD), 72 is a second modulator, 73 is a fourth amplifier 76a that amplifies the output signal of the second modulator 72,
76b is a second magnetic head group attached to the rotating transformer 56, 77 is a sixth amplifier that amplifies the signals reproduced by the magnetic heads 76a and 76b, and 79 and 80 are BBDs.
81 is a sixth amplifier, 82 is a second output terminal, 83 is a compressor 70,
71 and the expanders 79 and 80.

The operation of the rotary head type magnetic recording/reproducing apparatus constructed as described above will be described below with reference to FIG. 1.

An image to be captured by a video camera is converted into an electrical signal by an image sensor 60 within the video camera.

At this time, the first signal processing circuit 51 performs control so that every 1 field time (approximately 16.7 mg in the case of the N TSO method) is converted into an electrical signal in 6μ of the 1 field time. A signal is given to the image sensor 60. In other words, the frequency of the horizontal synchronizing signal is increased by 1.2 times. The electric signal is converted into a video signal by a first signal processing circuit 51, and separated into a luminance signal and a color signal. The field period of this converted video signal remains the same, but the time axis is compressed.The image sensor 5o and the first signal processing circuit 51 act as a time axis compressor. The luminance signal and chrominance signal outputted from the circuit 51 are applied to the first modulator 62, and become a mixed wave of the luminance signal as a frequency modulated wave and the chrominance signal that has been low frequency converted.

After this mixed wave is amplified by a first amplifier 53, it passes through a first switch 54 switched to the R side and a first rotary transformer 55, and then passes through a first magnetic head group attached to a rotary cylinder 66. The magnetic heads 572L, 5 that constitute the
Added to 7b. However, the magnetic heads 5a and 57b are attached very close to each other. The rotary cylinder shell is rotated by a motor 61 and controlled by a control device 62 to rotate once per field period.

The magnetic tape 60 is wound around the rotary cylinder 56 obliquely at an angle slightly larger than 300 degrees by force ζ guide bins 58 and 59, and is run in the direction of the arrow by a tape running device (not shown). Furthermore, the video signal converted by the first signal processing circuit 51 is
Since one field is compressed into 6/6 of the time, the magnetic head 57! While L or 57b is in contact with the magnetic tape 60, the signal for one field is sent to the magnetic head 571L.
and 57b, and the tracks on the magnetic tape 60 are oblique to the running direction of the magnetic tape 60.
The signal for one field is recorded.

The diameter of the rotating cylinder 56 is set to 3/6 of the conventional configuration, the azimuth angle of the helad gap of the magnetic head 571L is set to +6 degrees, and the azimuth angle of the head gap of the magnetic head 57b is set to -6 degrees. Therefore, the length and recording condition of the recorded diagonal toranau are the same as those recorded using conventional high-fidelity video. In addition, the signal processing circuit 610 time compression pressure operating rotary cylinder 66
In order to synchronize the rotation with the rotation, a control device 62 controls the rotation.

On the other hand, the audio signal applied to the input terminal 68 is amplified by a third amplifier 69, and then applied to compressors 70 and 71, which are time-base compressors composed of a low-pass filter, a BBD, and the like. BBDl in the compressor 70 includes a control circuit 8
3, a clock with a certain predetermined frequency f1 is applied for a time slightly longer than the time corresponding to one field. Next, BBDl has a frequency of 1.2 times the frequency f1.
A clock with f' 2 is applied to read the contents of BBDl. As a result, the audio signal has a time axis of 1.2
compressed twice. In other words, the audio signal for a time corresponding to one field is compressed to 5/6. The compressor 71 operates in a similar manner, but after a time corresponding to one field from the time when the clock of frequency f1 is applied to BBDl in the compressor 70, the frequency f is applied to BBD2 in the compressor 71.
1 clock is given. Then, after a time slightly longer than the time corresponding to one field, a clock of frequency f2 is applied and the contents of BBD2 are read out. Compressor 7
Since o and 71 work alternately, it is also correct to read BBDI as BBD2 and BBD2 as BBDl.

This situation is shown in the timing chart showing the passage of time in FIG. The horizontal axis in FIG. 2 represents the passage of time, and shows the timing of applying the clock frequencies f1 and f2i to BBDl and 2 and the timing of the compressed signal applied to the second modulator 72. In FIG. 2, the portion of the input signal to the modulator 72 surrounded by a solid line is a compressed signal portion, and the portion surrounded by a broken line is a signal portion that is not used. Note that BD1 and BD2 have a number of stages in which all packets appear at the same time in a period when a clock of frequency f1 is applied.

Further, the compressors 70 and 71 are provided with gates so as to output only when a clock of frequency f2 is applied.

The audio signal time-compressed in this way is sent to the compressor 70.
and 71 alternately, so the two are mixed and the second
modulator 72. In the second modulator 72, a carrier having a frequency 1.2 times that of a conventional high-fidelity video is frequency modulated, and its output signal is amplified by a fourth amplifier 73, and then the output signal is amplified by a fourth amplifier 73. 2 switch 74
and the rotary cylinder 6 via the second rotary transformer 76
The magnetic heads 62L and 76b are added to the second magnetic head group attached to the second magnetic head group 62L and 76b. However, the magnetic heads 761L and 76b are attached very close to each other, and the azimuth angles of the respective magnetic heads are selected to be -30 degrees and +30 degrees.

Here, since the compression operation of the audio signal must be synchronized with the rotation of the rotary cylinder 56, the control circuit 83 receives a control signal from the control device 62. Because of this operation, the frequency modulated wave of the audio signal is recorded on the magnetic tape 60 in the same manner as in the case of conventional high-fidelity video recording, similar to the case of video signals. Then, the magnetic heads 571L, 57b are set so that the tracks recorded by the magnetic head 762L are covered by the tracks recorded by the magnetic head 67a, and the tracks recorded by the magnetic head 76b are covered by the tracks recorded by the magnetic head 57b.

The positions and heights of the attachments 76a and 76b to the rotating cylinder 66 are determined.

By recording on the magnetic tape CO in this way, the recording state of the recorded magnetic tape 6O is the same as that recorded with conventional high-fidelity video, and it can be played back with conventional high-fidelity video. Let's talk about regeneration. The rotation of the rotating cylinder 66 is controlled by the control device 62 so that the magnetic head yb'=travels along the track recorded on the magnetic tape 60, and the traveling of the magnetic tape 60 is controlled by a tape traveling device (not shown). controlled. In this way, the luminance signal as a frequency modulated wave and the low frequency converted color signal recorded on the magnetic tape 60 are reproduced from the magnetic heads 571L and 57b. This regenerated signal is sent to the second amplifier 6 via the first rotary transformer 56 and the first switch 64 switched to the P side.
Added to 3.

The signal amplified by the second amplifier 63 is transmitted to the first demodulator 6
4, and is reconverted into a luminance signal and a chrominance signal before being converted by the first modulator 52. These luminance signals and color signals are converted into video signals by the second signal processing circuit 66,
This video signal has a normal field period (approximately 18.7 m5 in the case of the NTSC system), but is time-compressed to 576. If you don't change the time axis, you won't be able to watch it on a regular TV screen. So time stretcher 66
The time is expanded and the signal is returned to a normal video signal. The video signal obtained in this way is output to the first output terminal 67.

By the way, the time expander e6 includes an analog-to-digital converter that converts the video signal into a digital signal, a memory for storing the video signal for two fields converted into the digital signal, and a memory for the digital signal. It consists of a control circuit that controls writing and reading, etc., and a digital-to-analog converter that converts digital signals into video signals. In its operation, the signal output from the second signal processing circuit 65 is converted into a digital signal by an analog-to-digital converter. Then, they are synchronized with a control signal from the control device 62, and the digital signal for one field is stored in the memory.

Next, the stored digital signal for one field is
By reading out the data at 5/6 times the writing speed, converting it with a digital-to-analog converter, and passing it through a low-pass filter, you can obtain a time-expanded normal video signal. Since the memory has two fields, if these fields are used alternately, a continuous video signal can be obtained. On the other hand, magnetic head 761L
The frequency modulated wave modulated by the audio signal reproduced by
added to. The output signal amplified by the fifth amplifier 77 is frequency demodulated by the second demodulator 78 and becomes an audio signal. However, this audio signal is obtained by compressing the audio signal corresponding to the time of one field into 6/6 of the time. Therefore, this compressed audio signal is applied to expanders 79 and 8o, which are time axis expanders, to expand the time axis and convert it into a normal audio signal. The signal is then amplified by the sixth amplifier 81 and output to the second output terminal 82 .

The expanders 79 and 80 are composed of low-pass filters, BBDs, etc., and their operations will be explained next.

The compressed audio signal is sent from the second demodulator 78 to the decompressor 7
9, a certain predetermined frequency f2 is transmitted from the control circuit 83 controlled by the control device 62.
The clock held by i is given to BBD3 a time of 6/6, which is slightly longer than the time corresponding to one field.

Thereafter, a clock having a frequency r1 that is 6/6 of the frequency f2 is applied to the BBD3, and the contents of the BBD3 are read out. This will restore the time axis.

The compressed audio signal is also applied to BBD4 in the decompressor 80, and after a time corresponding to one field from the time when the clock of frequency f2 is applied to BBD3,
A clock of frequency f2 is given to BBD4. Then, after a time corresponding to one field from the time when the clock with the frequency f1 is applied to the BBD3, the clock with the frequency f1 is applied to the BBI)4, and the contents of the BBD4 are read out. The control circuit 83 supplies clocks at different timings so that the full expanders 79 and 80 perform such operations alternately. In addition, the expanders 79 and 80 are provided with gates so that the clock signal of frequency f1 is output for a time corresponding to one field from the time when the clock of frequency f1 is applied, so if the outputs of the expanders 79 and 80 are mixed, A continuous audio signal is obtained.

Although the time axis of the video signal is compressed in the signal processing circuit 51, a compressor that performs the opposite operation may be used in the configuration of the time axis expander 66.

Effects of the Invention As described above, the present invention provides a time base compressor that compresses the time base of an input signal having a predetermined time width, a rotary cylinder that rotates once in the time width, and a rotary cylinder that is attached to the rotary cylinder. By providing at least two pairs of compressed magnetic heads and a time axis expander that restores the compressed time axis, the same function as conventional high-fidelity video is achieved using a rotating cylinder with a smaller diameter than before. be able to.

Moreover, the magnetic tape recorded by the rotating head type magnetic recording/reproducing device of the present invention is the same as that recorded in conventional high-fidelity video, and the magnetic tape is compatible, making it possible to realize high-fidelity video with a smaller device. .

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a rotary head type magnetic recording/reproducing device according to an embodiment of the present invention, Fig. 2 is a timing chart showing the time course of operation, Fig. 3 is a block diagram of a conventional high-fidelity video, and Fig. 4 is a conceptual diagram of a truck. 60...imaging device, 61. θ5...Signal processing circuit, 52.72...Modulator, 56...
... Rotating cylinder, 57 & , 57b , 76 &
, 76b--Magnetic head, 60... Magnetic tape, 62... Control device, 64.78...
... Demodulator, 66 ... Time expander, 70.7
1... Compressor, 79.80... Expander. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (3)

[Claims] (1) first and second time base compressors that compress the time bases of first and second input signals having a certain predetermined time width; first and second modulators that receive output signals as input; first and second amplifiers that amplify the output signals of the first and second modulators;
a rotating cylinder that rotates once in the time width; a control device that controls rotation of the rotating cylinder; at least one pair of first magnetic heads each having a different azimuth angle attached to the rotating cylinder; at least one pair of second magnetic head groups each having an azimuth angle different from that of the first magnetic head group and each having a different azimuth angle; a tape running device, third and fourth amplifiers that amplify reproduction signals of the first and second magnetic head groups, and first and second amplifiers that receive output signals of the third and fourth amplifiers; a demodulator, and the first and second
and first and second time base expanders that receive the output signal of the demodulator as input and expand the time base compressed by the first and second time base compressors to the original time base. A rotating head type magnetic recording and reproducing device characterized by: (2) The rotation cylinder is moved so that the first track on the magnetic tape on which the first magnetic head group runs is covered by the second track on the magnetic tape on which the second magnetic head group runs. Claim 1, characterized in that the mounting positions and heights of the first and second magnetic head groups are set.
The rotary head type magnetic recording and reproducing device described in 1. (3) The azimuth angle of the head gap of the first magnetic head group was set to +30 degrees and -30 degrees, and the azimuth angle of the head gap of the second magnetic head group was set to +6 degrees and -6 degrees. A rotary head type magnetic recording/reproducing device according to claim 2, characterized in that the rotary head type magnetic recording/reproducing device is characterized in that: