JPH0115009Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a magnetic tape playback device, and particularly to a magnetic tape playback device that allows the tape running speed to be set at any speed within a variable range from zero to, for example, about 10 times the tape running speed during recording. The present invention relates to a magnetic tape reproducing device that has an operating member such as a dial that can change the running speed, and that reproduces recorded signals on a magnetic tape at the running speed.

Conventional technology It has been known to prepare two or more VTRs and perform electronic editing by inserting and recording video signals played by another VTR on a pre-recorded magnetic tape, or by recording spliced footage. .
FIG. 1 shows a block system diagram of an example of a general electronic editing system. In the figure, a video signal and an audio signal reproduced from a recorded magnetic tape by a reproduction device 1 are transmitted to a reproduction video signal input terminal 6V of a recording and reproduction device (VTR) 5 via output terminals 2V and 2A, respectively.
and the reproduced audio signal input terminal 6A, and is also supplied to the monitor device 7. The playback device 1 is supplied with a control signal from the controller 4 to its remote control terminal 3, and the recording and playback device 5 is supplied with a control signal from the controller 4 to its remote control terminal 8, thereby controlling its operation.

The recording/reproducing device 5 splices or inserts the reproduced video signal and reproduced audio signal from the input terminals 6V and 6A into a position on the magnetic tape intended by the editor. In order to search for the recording position of the video signal and audio signal to be electronically edited, the reproduced video signal and the reproduced audio signal of the reproduction device 1 are monitored and reproduced by the monitor device 7. In addition, at the editing point at which the recording/reproducing device 5 should start splicing recording or insert recording, the recording/reproducing device 5 is set in the playback mode in advance, and the reproduced video signal and the reproduced audio signal are transmitted to the monitor device 1 via the output terminals 9V and 9A.
0, and this causes the monitor to reproduce the search result. Furthermore, the monitor device 10 can also monitor and reproduce the reproduced video signal and reproduced audio signal from the recorded magnetic tape after electronic editing, thereby making it possible to confirm the results of electronic editing.

In the electronic editing described above, both the playback device 1 and the recording and playback device 5 are equipped with a search dial that allows the editor to arbitrarily change the tape running speed within a range from zero to, for example, about 10 times the recording speed. Depending on the rotation angle of this search dial, the magnetic tape is made to run in the same direction (forward direction) or in the opposite direction to that during recording, and at a predetermined running speed depending on the rotation angle. Or it is stopped, the previously recorded signal on this magnetic tape is reproduced, and the input reproduction signal is recorded. The search dial is suitable for electronic editing because it is possible to locate the beginning of the recorded magnetic tape in any playback direction.

Problems to be Solved by the Invention However, in the above-mentioned electronic editing work, in the sense of comparing with real time, monitoring and reproducing the recorded signal in the normal playback mode is faster than the above-mentioned tape running speed, that is, the playback speed. This can often occur during playback within a variable range. in this case,
Conventionally, it was necessary to press a play switch to switch to normal playback, and to press a search switch and then operate a search dial to switch from normal playback to variable speed playback. For this reason,
When transitioning from normal playback to variable speed playback, or from variable speed playback to normal playback, release your hand from operating the search dial, press the search switch or play switch, and then grasp the search dial again. However, this poor operability had a great effect on users who perform electronic editing professionally.

Therefore, the present invention has been developed so that the operation member for varying the tape running speed, such as a search dial, can be operated in both the forward and reverse directions.
The above problem was solved by installing a click at the scale position near double speed and a switch that turns on at the click point, and by forcing the device to play at 1x speed when this switch is turned on. The purpose is to provide a magnetic tape playback device.

Means for Solving the Problems The present invention has a structure in which the playback speed variable operation member has a switch that is turned on at a click point when the scale position of the operation member reaches a position where the tape running speed is approximately the same as that during normal playback. and a circuit that generates at least a signal for switching the output signal of the phase control system of the servo circuit of the capstan for running the magnetic tape to the same output signal as during normal playback, based on the signal obtained by turning on the switch. When the switch is turned on, it is forced to 1.
The apparatus is configured to perform double-speed reproduction, and one embodiment thereof will be described below with reference to FIG. 2 and the subsequent drawings.

Embodiment FIG. 2 is an external perspective view of an example of a recording/reproducing apparatus to which the device of the present invention can be applied, and FIG. 3 is a partially enlarged front view of the main part of FIG. 2. In both figures, recording and reproducing device 11
A search dial 12 is provided on the right side of its front panel. The search dial 12 changes the tape running speed from zero to a speed faster than that during recording (here,
The dial is an example of an operating member for selecting an arbitrary tape running speed, that is, playback speed, within the range up to 10x speed), and its scale 12a is a scale ("STILL", "X-1", "X1", "X10", "X-10"
”
etc.). Therefore, in FIG. 3, the scale 12a is the scale "STILL".
Therefore, the search dial 12 indicates the still motion playback speed at which the tape running speed is zero. Also, as the scale 12a rotates clockwise from the point where it matches the "STILL" scale shown in Figure 3, the tape running speed increases (up to 10 times the speed), and the running speed is in the same direction as when recording. (forward direction), and on the other hand, as the scale 12a rotates counterclockwise from the position shown in FIG. You can choose to be in the opposite direction from when recording.

Further, a cassette insertion/removal opening/closing door 13 is provided at the upper center of the front panel. This opening/closing door 1
3 consists of an upper opening/closing door 13a and a lower opening/closing door 13b as shown in FIG.
The cassette is moved in the X ₁ direction and abuts the upper door _13a and the lower door 13b, respectively, and
When inserted into the back of the device 11 in the direction, the opening/closing door 13
a opens upward, and the opening/closing door 13b opens downward, and the cassette is loaded into the cassette housing of the device 11. This closes the opening/closing door 13a and closes the cassette insertion/removal port. Furthermore, 1
4 is a power switch, and 15 is a play switch.

According to this embodiment, the scale 12a of the search dial 12 is at the scale position "X1" indicating the 1x playback speed in the forward direction in FIG. 3, or the 1x playback speed in the reverse direction. It is characterized by a structure in which a switch (indicated by 16 in FIG. 4) is provided, which is turned on at each click point when the indicated scale position "X-1" is reached.

FIG. 4 shows a block system diagram of one embodiment of the device of the present invention. In the same figure, the signal generating circuit 17 controls the ON/OFF operation of the switch 16 and the playback direction command signal from the input terminal 18 (this corresponds to the scale 1 of the search dial 12).
2a is on the right side or left side of the "STILL" position). For example, a microcomputer can be used. That is, during a search (during variable speed playback) when the switch 16 is off, the signal generation circuit 17 operates regardless of the logical value (playback direction) of the playback direction command signal from the input terminal 18.
Capstan motor drive command signal to output terminal 19
CM, a capstan servo switching command signal CS to the output terminal 20, and a drive command signal for the motor that rotates the rotating body (for example, a rotating drum) to which the rotating head is attached to the output terminal 21.
DM is output, and a command signal DS for turning off the phase control system of the head servo circuit is output to the output terminal 22.
Further, the signal generating circuit 17 outputs a head selection command signal VS for selecting a rotary head for variable speed reproduction as the reproducing rotary head to an output terminal 24, and a reference signal switching signal ST for the phase control system of the head servo circuit to an output terminal 23. is not output. Note that each of the above command signals is a binary signal, and when a signal is output, it means a high level (or low level), and when a signal is not output, it means a low level (or high level).

Here, as shown in FIG. 5, the recording and reproducing apparatus 11 has rotary heads H ₁ and H ₂ for normal recording and reproducing mounted on a rotary drum 26 facing each other, and the rotary heads H 1 , H ₂ facing each other. A rotary head for variable speed reproduction is placed at a position that is up and down in the rotational direction relative to _H2 .
H _A and H _B are installed facing each other.
The rotating heads H ₁ and H ₂ have different azimuth angles from each other, and _the rotating heads H _A and H _B have a larger track width than the rotating heads H _{1 and H 2 .} The same azimuth angle as either one of H ₂ is selected. The magnetic tape 27 is guided by guide poles 28 to 31 and wound around the rotating drum 26 over an angular range of over 180 degrees, and is pinched and driven by a capstan and pinch rollers (none of which are shown). It is made to run in the direction of arrow X ₂ (forward direction) or in the direction of arrow X ³ (reverse direction). Head selection command signal mentioned above
VS connects heads H ₁ , _{H 2 , H A ,}
This is a signal that controls switching of the switch circuit that switches the output terminal of H _B.

By outputting a command signal during variable speed playback when the switch 16 is off, the phase control system of the capstan servo circuit shown in FIG.
is rotated, the phase control system of the head servo circuit is turned off, and the rotation of the head motor is controlled so that the reproduction synchronization signal has a constant frequency with a voltage corresponding to the rotational speed of the capstan motor 33.

Next, the operation when the scale 12a of the search dial 12 is made to match the scale "X-1" or "X1" will be described. At this time, as described above, the switch 16 shown in FIG. 4 is turned on, and the same signal as the command signal for commanding the tape running speed is input to the input terminal 18. As a result, the signal generation circuit 1
7 outputs at least command signals CM, DM, and SI, and stops sending out the command signal CS.

Here, during normal playback performed by pressing the play switch 15 shown in FIGS. 2 and 3, the signal generation circuit 17 outputs command signals CM and DM.
Sending of the remaining command signals CS, etc. is stopped. Therefore, in the above case where the switch 16 is turned on,
This is similar to normal playback in that the command signals CM and DM are output, and at least the transmission of the command signal CS is stopped. As a result, when the search dial 12 reaches the scale "X-1", "X1" for single-speed playback, single-speed playback, which is substantially equivalent to normal playback, will be performed.

Next, an example of a capstan servo circuit to which the above command signals CM and CS are supplied will be explained with reference to FIG.

In the figure, the rotation of a capstan motor 33 is detected by a capstan pickup head 34. A rotation detection pulse having a repetition frequency proportional to the rotational speed of the capstan motor 33 taken out from the head 34 is supplied through an amplifier 35 to a frequency divider 36 and F-V converters 37 and 38, respectively. Further, the output command signal from the output terminal 20 is supplied to the switching pulse generation circuit 40 via the input terminal 39. On the other hand, a drive signal of a voltage corresponding to the search speed is input to the input terminal 41 in the search mode (variable speed reproduction mode), and this signal is supplied to the switch circuit 42. The switching pulse generation circuit 40 receives a search command signal from the input terminal 39.
When CS comes in, that is, during variable speed playback, it generates and outputs switching pulses that turn on switch circuits 42 and 43, respectively, and also supplies switching pulses to switch circuits 45 and 46 via inverter 44 to turn them on. is off. On the other hand, when the search command signal CS does not enter the input terminal 39, that is, during recording and normal playback, a switching pulse is generated that turns off the switch circuits 42 and 43, respectively, and turns on the switch circuits 45 and 46, respectively. Output.

On the other hand, the rotation detection pulse whose repetition frequency is set to, for example, 30Hz by the frequency divider 36 is sent to the switch circuit 4.
The voltages obtained by frequency-voltage conversion of the rotation detection pulses by the F-V converters 37 and 38 are supplied to the terminal R of the switch circuit 46,
43. In addition, a pulse obtained by dividing the vertical synchronization signal by 1/2, for example, enters the input terminal 48.
The signal is supplied to terminal R of the switch circuit 49. The oscillator 50 is a circuit that outputs a signal that is also supplied as a reference signal to the phase control system of the head servo circuit (not shown).
It is supplied to terminal P of 9.

The switch circuits 47 and 49 are connected to the terminal R side during recording, and are switched to the terminal P side during playback. Therefore, during recording, the output signal of the frequency divider 36 is sent to the switch circuit 4 as a comparison signal.
7 to the phase comparator circuit 51, while
An input signal at the input terminal 48 is supplied to the phase comparator circuit 51 as a reference signal through a switch circuit 49. Further, during reproduction, a control pulse of, for example, 30 Hz reproduced from a control track on the magnetic tape by the control head 52 is supplied as a comparison signal to the phase comparator circuit 51 through the amplifier 53 and the switch circuit 47, while the oscillator 5
The output signal of 0 is supplied through the switch circuit 49 to the phase comparator circuit 51 as a reference signal.

The phase comparison circuit 51 is configured to generate a trapezoidal wave from a reference signal and sample and hold the slope of this trapezoidal wave using a comparison signal, and its output phase error voltage is supplied to the switch circuit 45. be done.

As mentioned above, the switch circuits 42, 43, 4
Of the switch circuits 5 and 46, the switch circuits 45 and 46 are turned on only during recording or normal reproduction, so that the output phase error voltage of the phase comparator circuit 51 passes through the switch circuit 45 to the output of the mixing amplifier 54 during recording or normal reproduction. The output voltage of the F-V converter 37 is supplied to the inverting input terminal of the mixing amplifier 54 through the switch circuit 46. The output voltage of the mixing amplifier 54 is supplied to the capstan motor 33 through a motor drive amplifier (MDA) 55, and its rotational speed is controlled to be constant and the rotational phase is controlled to be synchronized with the input signal of the input terminal 48. Ru.

The MDA 55 is supplied with a rotation direction command signal from an input terminal 56 (the same signal as the command signal input to the input terminal 18 in FIG. 4), and controls the rotation direction of the capstan motor 33. Also MDA
A capstan motor drive command signal CM is supplied from the output terminal 19 through the input terminal 57 to enable the capstan motor 33 to rotate.

Here, during variable speed playback other than 1x speed playback, the switch 16 is off as described above, and the switch circuits 42 and 43 of the switch circuits 42, 43, 45, and 46 are turned on, respectively, so that the mixing amplifier 54 A motor drive signal having a level corresponding to the playback speed is supplied to the non-inverting input terminal of , through an input terminal 41 and a switch circuit 42, respectively. Further, an F-V converter 3 whose characteristics are controlled to be changed by a voltage corresponding to the playback speed from an input terminal 58
The output voltage of 8 is supplied as a speed control voltage to the inverting input terminal of the mixing amplifier 54 through the switch circuit 43. The output signal of this mixing amplifier 54 is
By applying the voltage to the capstan motor 33 through the MDA 55, the rotation speed of the capstan motor 33 is determined by the motor drive signal at a level corresponding to the playback speed from the input terminal 41, and the rotation speed is determined by the signal from the input terminal 56. The direction is determined and it is rotated or stopped.

On the other hand, in this embodiment, when the switch 16 is turned on, the command signal CS is not supplied to the input terminal 39 as in the case of normal playback, so the switch circuits 45 and 46 are turned on, respectively. In addition, since the switch circuits 42 and 43 are respectively turned off, the output signal of the phase control system of the capstan servo circuit is switched to the output signal of the phase comparator circuit 51 as in the normal reproduction. Therefore, when the search dial 12 is rotated to match the "X-1" or "X1" scale, the capstan servo circuit operates almost the same as during normal playback, and the recording/playback device 11 forcibly performs a single speed playback operation.

In the phase control system of the capstan servo circuit, during normal playback, the playback control pulse of the control head 52 is supplied as a comparison signal to the phase comparator circuit 51, so that during normal playback, the playback control pulse of the control head 52 is supplied to the phase comparator circuit 51 as a comparison signal. X-1), the reproduction control pulse is detected in an opposite phase to that during normal reproduction, causing a track shift. However, in this case, the rotary heads H _A and H _B with large track widths shown in FIG. 5 are used as playback heads.
is used, so there is almost no effect on the reproduced image due to track deviation. Further, during single-speed playback in the forward direction (when set to scale "X1"), the same rotation heads H ₁ and H ₂ as during normal playback are used.

Application example Note that the operation member for varying the playback speed is not limited to one that uses a rotational operation such as the search dial 12.
It may be a linearly operated fader or the like, and the click may not be at the exact 1x speed playback position, but may be in the vicinity thereof. Furthermore, the signal generation circuit 17 can be configured by a microcomputer.

Effects As described above, according to the present invention, the single playback speed variable operation member continuously adjusts the playback speed (tape running speed) even within the range of tape running speed from zero to a speed faster than that during recording. ), and in addition to the maximum speed of about 10x playback, it is also possible to control 1x playback, which is essentially the same as normal playback, and thus allows for the transition from one of normal playback and variable speed playback to the other. Since operations can be performed using only a single operating member, operability is improved, especially when applied to the playback device of an electronic editing system.
It has a great effect on work efficiency, and the structure of the operating member itself, which has a switch that turns on at the click point, can be manufactured at low cost.Furthermore, by operating the operating member, it is possible to change the normal playback image to It has features such as being able to view close images.

[Brief explanation of the drawing]

FIG. 1 is a block system diagram showing an example of a general electronic editing system, FIG. 2 is an external perspective view showing an example of a recording and reproducing device to which the device of the present invention can be applied, and FIG.
Figure 2 is a partially enlarged front view of the main parts of the illustrated device, Figure 4 is a block system diagram showing an embodiment of the device of the present invention, and Figure 5 is the arrangement of the head of the device of the present invention and its positional relationship with the tape. FIG. 6 is a plan view showing an example, and FIG. 6 is a block system diagram showing an example of a capstan servo circuit to which signals from the device of the present invention are supplied. 1... Playback device, 2A, 9A... Playback audio signal output terminal, 2V, 9V... Playback video signal output terminal, 4... Controller, 5... Recording and playback device,
11...Recording/reproducing device, 12...Search dial, 16...Switch, 17...Signal generation circuit,
18...Reproduction direction command signal input terminal, 19-24
...Command signal output terminal, 33...Capstan motor, 39...Command signal CS input terminal, 40...
Switching pulse generation circuit, 54...Mixing amplifier, 55...Motor drive amplifier (MDA), 56
...Rotation direction command signal input terminal, 57...Command signal input terminal.

Claims (1)

[Scope of utility model registration request] In a playback device that uses a rotary head to play back recorded signals on a magnetic tape at a tape running speed arbitrarily selected by a playback speed variable operation member within a range of tape running speed from zero to a speed faster than that at the time of recording, said operation The member has a switch that is turned on at a click point when the scale position reaches a position where the tape running speed is approximately the same as that during normal playback, and the magnetic comprising a circuit that generates at least a signal for switching an output signal of a phase control system of a servo circuit of a capstan for running the tape to the same output signal as during normal playback;
A magnetic tape playback device configured to forcibly perform 1x speed playback when the switch is turned on.