JPH0258754A - Vtr - Google Patents

Abstract

PURPOSE:To perform excellent consecutive recording with a VTR by counting the rise time of a capstan motor and forming the drive starting timing of the motor based on the rise time. CONSTITUTION:When a capstan-on command signal is supplied to a timing forming block 2 from a terminal 1, drive starting timing which is delayed by a prescribed time lag from a reference frame synchronizing signal from a terminal 3 is formed and the timing is supplied to a capstan servo block 4 to drive a capstan motor 5. When the motor 5 is rotated, a servo error signal is generated and a regenerative CTL signals and the reference frame synchronizing signal are made almost coincident with each other in phase at the timing after the rise time of the motor 5. Thereafter, the phases are synchronized to each other by performing the servo. Moreover, CTL recording is started prescribed time after the phases are synchronized to each other. Therefore, excellent consecutive recording can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to, for example, a VTR for porta-pull in which linking operations can be performed.

[Summary of the invention]

The present invention relates to a VTR, and measures the rise time of the capstan motor, and uses this rise time to form the timing for starting the drive of the capstan motor, thereby enabling good continuous shooting. .

[Conventional technology]

For example, when performing splicing with V'1'R for portaple, conventionally the tape is rewound a predetermined amount and played back before starting splicing, so that the phase of the playback CTL signal and a predetermined reference synchronization signal match. The current practice is to perform a training run in order to achieve a transition maneuver without any disturbance in the CTL pitch.

However, the above-mentioned start-up may take an extremely long time depending on the initial phase difference, and if the amount of rewinding is determined taking this time into account, rapid continuous shooting will not be possible.

Therefore, we measured the start-up time of the capstan motor,
It has been considered to adjust the timing of starting driving of the cap and tongue motors so that the phase of the reproduced C'rL signal after rising substantially matches the reference synchronization signal.

[Problem to be solved by the invention]

However, the rise time of the above-mentioned capstan motor varies widely from motor to motor, and conventionally adjustments are made while looking at the waveform of the reproduced signal during the adjustment process during manufacturing, but this requires skill and requires high precision. It was also difficult to make adjustments.

Furthermore, even if such adjustments are made, there is a risk that the start-up time will fluctuate due to changes in the surrounding environment, decrease in battery voltage, changes over time, etc., and it is necessary to compensate for these by installing a temperature center and voltage detection circuit. occurred, and it was not possible to make such a correction for changes over time.

This appearance was made with this in mind.

[Means to solve the problem]

The first means for solving the problem in the present invention is to measure the rise time of the capstan motor, use this rise time to calculate the amount of timing delay from a predetermined reference synchronization signal, and calculate the result of this calculation. At the same time, the stored delay amount written in - is used to form the drive start timing of the capstan motor, and the CT is executed.
It is v′1゛E that can realize stable connecting operation of L pitch.

A second means measures the rise time of the capstan motor at V']'H of the first means, and uses this measurement value to start driving the capstan motor during the continuous shooting. This is v'rR, which corrects the timing of .

[Effect]

According to this, the rise time of the capstan motor is measured, and the drive start timing is determined based on this rise time, making it possible to form highly accurate timing with a simple configuration. This allows you to take good continuous shots.

Furthermore, by constantly measuring the rise time, the timing can be easily corrected for changes over time.

〔Example〕

FIG. 1 is a block diagram showing the functions of the main parts.

In the figure, when the capstan-on command signal from the terminal (1) is supplied to the timing formation block (2), a predetermined signal is applied to the reference frame synchronization signal (Ref/VD) from the terminal (3). delay time T.

The driving start timing is determined, and this timing is supplied to the block cock (4) of the capstan servo to drive the capstan motor (5).

So for example! 2 When a capstan-on command signal as shown in Figure B is supplied in response to a reference frame synchronization signal as shown in Figure A, the timing of the next synchronization signal ■
A delay time ゛rD is provided starting from ``rD'', and a timing ``2'' for starting driving the capstan motor (5) is formed.

When this timing (2) is supplied to the block cock (4) to drive the capstan motor (5), a servo error signal due to the rotation of the motor (5) is generated as shown in the figure. Then, at timing ◎ after the start-up time of the motor (5) from timing ■, regeneration C shown in E of the same figure.
The phases of the 'r L signal and the reference frame synchronization signal (A in the same figure) are substantially matched, and the phases are synchronized by performing servo thereafter. Further, each time recording of the CTL is started after a predetermined period of time after the phases are synchronized, as shown in FIG. Note that the recording of the CTL may be performed at the same time as the inversion of the CTL, but more stable recording can be achieved by writing off a portion a little earlier.

And in this time chart, the timing
- Time is a fixed time determined by the reference frame synchronization signal (for example, 9 V D -150m!+ec,)
However, since the time of the timing ■-@ varies by 51 depending on the motor, the delay time ゛1゛D was adjusted and the result was 4(!J).

However, if we can measure the time ゛1゛ of In (, Kuikung Φ) - 〇 in this time chart 1, then this time ′1
゛Timing ■-(R time, for example 150m!He
By subtracting G from c, it is possible to find the necessary delay time {1}D.

Therefore, in the above-described apparatus, the timing 1 from the block 1:1 block (2) is supplied to the block 11 block (6) of the counter to start counting. On the other hand, the previously recorded cTL is reproduced by driving the cab stan motor (5), and this reproduction signal is supplied from the terminal (7) to the switch (8). Furthermore, the output of the frequency generator (FG) driven by the motor (5) is supplied from the terminal (9) to the peat detection block (10), and when the rotational speed of the motor (5) is near the target. The switch (8) is turned on. Then, the re/JHc TL multiplication signal from this switch (8) is supplied to the block (6) of the counter, and counting is stopped.

As a result, the count value corresponding to the timing ■-◎ is obtained. This count value is the delay amount calculation block 1:
The delay time '1'D described above is calculated. And this calculation result is the switch (12
) is supplied to the bank-up means (13) consisting of a 14" PROM, volume, etc., and the delay time ゛1゛D
The value corresponding to is saved.

During Zunawaji adjustment, the switch (12) is turned on, the block (2) is set to an arbitrary delay time, and the terminal (
1) is supplied with a capstan-on command signal. As a result, the rise time T of the motor (5) at timing ■-〇 is measured in block (6), and block (1
In step 1), a desired delay time '1'D is calculated. This measurement is further repeated, for example, eight times, and the average calculation result is stored in the bank up means (13).

Therefore, during normal operation, this stored value is used by the adder/subtractor (
14) to the block (2), and a drive start timing is formed which is one time within the above-mentioned delay time '1'D.

Furthermore, in the above-mentioned device 6, if there is a change in the rising time of Jζ Tanabata (5) due to changes in the surrounding environment, low voltage, changes over time, etc., G, 2 is L. At the time, the measurement by the counter block (6) described above is carried out;
This edge value is supplied to the supplementary value calculation block (15), and the rise time calculation block (16) is blocked from the value stored in the backup means (13). The inverse operation to (il) is performed and the result of this operation is supplied to the booklet dock (15). And this frock (
In step 15), the difference in value], that is, the arm end value is calculated, and this arm end value is supplied to the adder/subtractor (14) for correction.

In this way, according to the above-mentioned device, the rise time of the capstan motor is measured and the drive start timing is formed based on this rise time, so that it is possible to form a sieve-accurate Thai mink with a simple configuration. It is possible to perform a good continuous shot. Furthermore, by measuring the rise time at the time of seedling, the timing can be easily corrected for changes over time.

Note that in the above-mentioned apparatus, each functional block can be formed as, for example, software of a microcomputer, thereby making it possible to realize the above-mentioned apparatus without providing a new circuit device or the like.

Furthermore, in the above device, if the influence of changes over time is small, blocks (15) and (16) may not be provided, and values may be supplied to the backup means (13) by other methods. In this case, block (11) becomes unnecessary. However, if these are provided by software as described above, the burden will hardly increase even if they are provided together.

〔Effect of the invention〕

According to this invention, since the rise time of the capstan motor is measured and the drive start timing is determined based on this rise time, highly accurate timing can be formed with a simple configuration. You can perform good continuous shots. Furthermore, by constantly measuring the rise time, it has become possible to easily correct timing for changes over time.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an example of the present invention, and FIG. 2 is a diagram for explaining the same. (11 (31 (71+91 is the terminal, (2) is the block cock for timing formation, (4) is the capstan servo block, (5) is the capstan motor, (6) is the counter block, (8) ( 12) is a switch, (10) is a speed detection block, (11) is a delay amount calculation block, (13) is a back amplifier means, (14) is an adder/subtractor, (15) is a correction value calculation block, ( 16) is a block for calculating rise time.

Claims (1)

[Claims] 1. Measure the rise time of the capstan motor, use this rise time to calculate the amount of timing delay from a predetermined reference synchronization signal, save this calculation result, and A VTR that uses the above delay amount to form the timing of driving the capstan motor to realize continuous shooting with a stable CTL pitch.
. 2. In the VTR according to claim 1, the rise time of the capstan motor is constantly measured, and the measured value is used to correct the timing of starting driving of the capstan motor during continuous shooting. A VTR designed to do this.