JPS582402B2 - Jikiki Roku Saisei System - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention records and stores video signals extracted from various video sources and constituting still images in an audio magnetic tape recorder (preferably a so-called cassette telerecorder), and records and stores the video signals thus stored. This relates to a magnetic recording and reproducing system that is reproduced on a monitor television, and in particular uses a rotating magnetic sheet floating on a stationary table as a means of converting the time axis of the video signal used for recording and reproducing. The present invention relates to a magnetic recording and reproducing system characterized in that a magnetic head substantially in contact with the magnetic sheet is configured to be stationary or to rotate relative to each other.

In this type of system, a method has been proposed in which a rigid magnetic disk is used as the rotating magnetic recording medium and the rotation speed of the disk is changed, but such a method has the disadvantages that the rigid magnetic disk is expensive and the rotation speed of the rigid disk is When the number of revolutions is changed, the positional relationship of the floating magnetic head with respect to the rigid disk changes accordingly, which not only has the disadvantage that the characteristics before and after the change in the number of revolutions changes significantly, but also there is a risk of damaging the magnetic head. .

If the position of the magnetic head is adjusted before and after the fluctuation, the fluctuation in the characteristics can be alleviated, but a new adjustment mechanism is required.

On the other hand, the method of simply using a floating magnetic sheet in place of the rigid disk has the same drawbacks as above, since the amount of floating of the magnetic sheet fluctuates when the number of rotations of the magnetic sheet is changed.

FIG. 1 is a sectional view of a main part showing an embodiment of a time axis converting means that can be applied to a system according to the present invention, and FIG. 2 is a partially cutaway perspective view of a clutch used in the same means.

In FIG. 1, MS is a double-shaft magnetic sheet drive motor, and the motor uses NTSC video signals constituting a still image.
In the case of 1 frame, fH/525 revolutions per second, and in the case of 1 field, 2.5 revolutions per second. It rotates at a constant speed of fH/525 rotations (in ■, fH is the horizontal synchronization frequency).

Hereinafter, for convenience of explanation of the present invention, the video signal will be explained as a signal corresponding to one frame of the NTSC system.

MH is also a double-shaft head drive motor, and this motor is rotationally controlled at a slightly slower (or faster) speed than the motor MS, for example, fH/526 revolutions per second.

The following configuration is approximately symmetrical as shown in the figure with both motors as the center, and will be explained below according to the configuration on the left side, and the same component on the right side will be explained using the same figure number and the suffix R instead of L. Avoid duplication.

1L is a rotating shaft whose rotation is controlled by the seat drive motor at the above speed; 2L is a center hole 2aL that fits into the rotating shaft;
A protrusion 2bL that engages with the center hole of the magnetic sheet SL, and a flange portion 2CL that supports one surface near the center hole of the magnetic sheet.
The seat hub is fixed to the intermediate portion of the rotating shaft by a screw (not shown) such that the surface of the flange portion protrudes slightly from the surface of a stationary table, which will be described later.

3L attaches each motor to the bracket 4 on one side thereof.
The other side is a stationary table that supports the magnetic sheet SL by using airflow as a cushion when it rotates, and this table has a through hole 3aL through which the seat hub is inserted, and a rotation surface of the head drive motor. A through hole 3bL is formed through which the shaft 5L penetrates, and the surface supporting the magnetic sheet is made as smooth as possible to ensure smooth rotation of the magnetic sheet.

6L is a seat pressing body having a recess 6aL that engages with the protrusion 2bL of the seat hub and presses the other surface near the center hole of the magnetic sheet, and an opening 6bL through which the rotating shaft is inserted; The pressing body is attached to the seat hub removably or integrally.

7L has a magnetic head 8L fixed to its flange portion 7aL that substantially opposes the magnetic sheet SL, and a belt to be described later is stretched around the outer periphery of the cylindrical portion 7bL. The rotary shaft is rotatably attached to the rotary shaft via a bearing 9L, and movement of the rotary shaft in the axial direction is prevented by a washer IOL fixed to the rotary shaft.

A magnetic head 8L is provided on the cylindrical plane of the head disk 7L.
A slip ring 11L is provided which is electrically connected to the head disk, and a magnet 12L is provided at the flange portion of the slip ring 11L to detect the rotational phase of the head disk.

13L is a bracket attached to the stationary table 3L, and a brush 14L slidingly in contact with the slip ring and a rotating pulse detection head 15L arranged opposite to the magnet are attached to the bracket, respectively.

A magnet 16L is provided on the seat hub 2L, and a rotating pulse detection head 17L is provided on the stationary table 3L, which is arranged to face the seat hub 2L, and is used to detect the rotational phase of the seat drive motor. Since the rotational axes IL and IR of the motor are the same, it is only necessary to provide it on either the left or right side (the left side in the figure).

The rotating shaft 5L of the head driving moke and the stationary table 3L
A magnetic clutch 20L is provided between them, and the clutch controls the rotational driving force of the motor to be transmitted to the head disk or to be released from the transmission.

This magnetic clutch will be described below with reference to the partially cutaway perspective view of FIG. 2.

21L is a concave portion 21a around which the clutch coil 22L is wound.
The yoke is fixed to the pack plate 3L using an annular clutch choke having a through hole 21bL into which the rotating shaft 5L is inserted.

23L is a pulley having a plurality of through holes 23aL and a shaft hole 23bL, and the pulley has a bearing 24L installed in the shaft hole.
The washer 25L is rotatably attached to the intermediate portion of the rotating shaft through the washer 25L, and the axial direction of the rotating shaft is restricted by the washer 25L.

A belt 26L is stretched between the outer circumferential side of this pulley and the outer circumferential side of the cylindrical portion of the head disk.

27L is a clutch slider that is provided with a flange portion 27aL that is arranged opposite to the clutch choke 21L and comes into contact with one side of the pulley, and a convex portion 27bL that can be inserted through the through hole 23aL and protrude from the other side of the pulley; The slider is always urged by a clutch spring 28L so as to be in pressure contact with a drive disk, which will be described later.

29L is a drive disk fixed to the rotating shaft 5L with a screw 30L, and an annular clutch lining 31L is attached to the surface of the disk facing the convex portion 27bL of the slider.

When the clutch slider 27L is attracted by the clutch coil 22L, the frictional engagement between the slider and the drive disk 29L is broken, and the rotational force of the head drive motor is not transmitted to the head disk, keeping the magnetic head stationary. On the other hand, when the suction of the slider is cut off, the slider is brought into pressure contact with the drive disk by the clutch spring 28L, and the rotational force of the head drive motor is transmitted to the head through the rotation shaft SL of the motor, the drive disk 29L, the pulley 23L, and the belt 26L. The signal is transmitted to the disk 7L, causing the magnetic head attached to the head disk to rotate independently of the magnetic sheet.

Corresponding components of the pair of time axis converting means configured as described above will be distinguished by the prefixes "first and second" for convenience of explanation.

Next, the simplified block diagram of FIG. 3 showing an overview of the system according to the present invention will be explained.

40 is a television camera, 41 is a video signal processing circuit, and 42 is a monitor television.

The processing circuit 41 introduces a video signal captured by a television camera or received by a monitor television, processes the introduced signal by making full use of well-known processing techniques to make it suitable for magnetic recording, and further processes the processed signal. Recording system processing such as extracting video signals constituting a still image from the magnetic sheet, and reproduction system processing that reprocesses the video signals extracted from the magnetic sheet into signals suitable for displaying on the monitor television 42 are performed.

SIL and SIR are switches arranged between the signal processing circuit 42 and the first and second magnetic heads 8L and 8R, and specify the operation mode of both heads, that is, recording or reproduction, and these two switches are controlled by moving respectively. When one side is set to recording mode (contact R side), the other is set to playback mode (contact P side)
is set to

S2L, S3L and S2R, S3R are switches that can be switched by moving each other, and the switches S3L, S3L
is connected so that when the contact H side is closed, the first and second clutch coils 22L and 22R are energized, and when the contact L side is closed, the energization is cut off.

The switches S2L and S2R transmit the output of the signal processing circuit 41 to the first and second magnetic heads 8 when their contacts H side are closed.
L, 8R, and when the contact L is closed, the signals extracted by each magnetic head are sent to the recording amplifier circuit 43.
Alternatively, the output of the reproduction amplifier circuit 44 is introduced into each of the magnetic heads.

S4L and S4R are switches arranged between each of the magnetic heads and the recording and reproducing amplifier circuits, and specify the operation mode of both heads, that is, recording or reproducing.These switches are controlled in conjunction with each other, so that one When the recording mode (contact R side) is set, the other is set to the playback mode (contact P side).

45 is a model of an audio magnetic tape recorder (preferably a cassette type tape recorder).

S5 is a switch for setting the operation mode of the tape recorder; when the contact R side is connected, the tape recorder is set to the recording mode, while when the contact P side is connected, the tape recorder is set to the playback mode. .

A well-known servo system can be used for the sheet drive motor MS and the head drive motor MH.

The illustrated embodiment will be briefly described. Reference numeral 46 denotes a reference oscillator, from which an oscillation output having a horizontal synchronization frequency fH is derived.

47 is a 1/525 frequency dividing circuit, 48 is a circuit for amplifying the rotation pulse of the seat, and 49 is a seat servo circuit for comparing the outputs of both circuits and controlling the plow seat drive motor MS as the error output. show.

50 is a 1/526 frequency dividing circuit; 51 is a circuit that introduces and amplifies the rotational pulse of the first or second head disk via a selection switch S6; and 52 is a circuit that compares the outputs of the two circuits and uses it as an error output. A head servo circuit that controls the first or second head drive motor MH is shown.

FIG. 4 shows a model used to explain the operation of the system of the present invention, and models I to (2) represent signal waveforms at the same reference numerals in FIG.

Model I represents a video signal extracted from a camera or monitor television, etc., and model 2 represents a video signal constituting one frame of frequency-modulated still image derived from the signal processing circuit 41.

Model ■ represents a signal that is reproduced at low speed by the time axis converting means and recorded on the magnetic tape recorder 45 via the recording amplifier circuit 43, and model ■ represents a signal that is reproduced by the magnetic tape recorder and recorded at low speed on the time axis converting means. represents.

Model (2) represents a signal introduced from the time axis conversion means to the signal processing circuit 41, and model (2) represents a video signal derived from this signal processing circuit and provided to a monitor television.

Since the recording/reproducing operation via the first time axis converting means and the recording/reproducing operation via the second time axis converting means are complementary, only the former operation will be described below.

When the switches are connected as shown, the first clutch coil 22L is energized, so the first magnetic head 8L is not rotated by the head disk and remains stationary.

The video signal shown in the model ■ is sent to the magnetic head by the switch SI.
The magnetic field is introduced through the R contact of L and the H contact of switch S2L, and is recorded on concentric tracks of the first magnetic sheet SL during one rotation of the sheet.

Thereafter, when the switches S2L and S3L are connected to the contact L side, the power supply to the clutch coil is cut off, and as a result, the rotation of the head disk is controlled by the head drive motor.

Since the rotational speed of this magnetic head is selected to be a little slower (or faster) than the rotational speed of the magnetic sheet, the signal recorded on the magnetic sheet is time-base converted and sent to the switch S2.
After passing through the L contact of L, the P contact of switch S4L, and the recording amplifier circuit 43, the signal represented by model 2 is recorded on the magnetic tape recorder 45 via the R contact of switch S5.

Next, when the switch S5 is connected to the P contact and the switch S4L is connected to the R contact, the signal shown in the model (■) reproduced from the magnetic tape recorder is transmitted to the first magnetic sheet SL.
Recording is performed by the first magnetic head 8L rotating on the track.

It is possible to configure the structure so that the previously recorded signal is erased at an appropriate timing prior to this recording, but since the previously recorded signal can be erased even if superimposed recording is performed, if the deterioration in image quality due to this superimposed recording is acceptable. In this case, the consideration for erasing may be omitted.

After that, by connecting the switches S2L and S3L to the H contact and the switch SIL to the P contact, the first magnetic head becomes stationary and the video signal represented by the model V can be extracted by the head, and the extracted output is sent to the signal processing circuit. In step 41, the signal is demodulated as shown in the model (■) and displayed as a still image on a monitor television 42.

In this way, video signals constituting still images can be sequentially recorded on the magnetic tape recorder for each expansion time required by the time axis conversion means.

Therefore, in order to sequentially reproduce still images from a magnetic tape recorder recorded in this way on a monitor TV, it is necessary to set the period during which one magnetic head is recording the reproduction signal from the magnetic tape recorder on one magnetic sheet. Then, the signal recorded on the other magnetic sheet may be alternately switched using the other magnetic head so that the signal recorded on the other magnetic sheet is reproduced on a monitor television.

The control of each of the above-mentioned switches required for such switching or for sequentially recording video signals constituting a still image on a magnetic tape recorder is performed systematically by providing a separate program control means for such control. However, in order to simplify the explanation, the case where manual control is used is illustrated in this embodiment.

FIG. 5 shows another embodiment of the time axis converting means that can be used in the system of the present invention.

Compared to the embodiment shown in FIG. 1, the required structure can be simplified, such as by omitting one magnetic sheet and one stationary table for supporting the magnetic sheet with an airflow cushion interposed therebetween.

Although each component of this embodiment will be given the corresponding figure number in FIG. 1, I believe that the operation of this embodiment will be obvious if the configuration and operation description of FIG. 1 are inferred.

In the system of the present invention as described above, a soft magnetic sheet is used as a time axis converting means, and the time axis can be converted without changing the rotation speed of this magnetic sheet. The relational relationship does not change.

Therefore, there is a system in which a video signal extracted from a video source via such time axis conversion means is recorded on an audio magnetic tape recorder, and vice versa, a reproduced signal from the tape recorder is displayed on a monitor television. There is no concern that image quality will deteriorate in the system.

It is also much cheaper than conventional systems that use rigid magnetic disks.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a time axis conversion means that can be applied to the system of the present invention, FIG. 2 is a partially cutaway perspective view of a magnetic clutch used in the same means, and FIG. A simplified block diagram showing the outline of the system of the present invention, Fig. 4 I~
(2) is a model for explaining the operation of the system, and FIG. 5 is a sectional view of a main part of another embodiment of the above-mentioned means. Explanation of main drawing numbers, SL, SR...First and second magnetic sheets, 3...Stationary table, MS...
・Sea 1・Drive motor, 8L, 8R...First and second magnetic head, MH...Head drive motor, 4
0...Television camera, 42...Monitor TV, 41...Signal processing circuit, 45...
...Audio magnetic tape recorder.

Claims (1)

[Scope of Claims] 1. A means for controlling constant speed rotation so that the first and second magnetic sheets are respectively levitated relative to a stationary table, and a first and second magnetic head that substantially opposes each of the magnetic sheets. means for controlling the rotation at a relative speed lower than the relative speed with each of the magnetic sheets in a stationary state; and an image forming a still image on a concentric first track of the first magnetic sheet by the first magnetic head. means for recording signals with the first magnetic head in a stationary state; and a means for reproducing a video signal stored on the first track by the first magnetic head whose rotation is controlled by the head rotation control means, so that the video signal is recorded on the first track. means for recording signals in the length direction of a tape of an audio magnetic tape recorder; and a means for recording video signals reproduced from the magnetic tape recorder onto concentric second tracks of the second magnetic sheet by the second magnetic head. means for recording with the second magnetic head under rotational control by the head rotation control means; and means for reproducing the video signal recorded on the second track with the second magnetic head stationary. A magnetic recording and reproducing system. 2. Constructing a still image on a concentric first track of the magnetic sheet using a means for controlling the rotation at a constant speed so that the magnetic sheet is levitated relative to a stationary table, and a first magnetic head that substantially opposes the magnetic sheet. means for recording video signals with the first magnetic head in a stationary state; and controlling the rotation of the first magnetic head at a relative speed lower than the relative speed between the first magnetic head and the magnetic sheet when the first magnetic head is in a stationary state. means for reproducing the video signal stored on the first track by the rotating first magnetic head and recording the video signal in the length direction of the tape of the audio magnetic tape recorder; A video signal reproduced from a tape recorder is transferred onto a second concentric track of the magnetic sheet, the second track being rotated at the low relative speed.
A magnetic recording and reproducing system comprising: means for recording with a magnetic head; and means for reproducing a video signal recorded on the second track with the second magnetic head stationary.