JPS6045959A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain precisely composite photographing by controlling correctively reel position so that a stored reel position at the start of unloading coincides with a detected current reel position. CONSTITUTION:An output from a reel rotation sensor 21 is counted up or down by a counter forming a reel position detecting means B in a control circuit 24 in accordance with an unloading start detecting output from a recording end detecting circuit 22 and a reel position at the start of unloading is stored in a RAM A. A driving motor 26 is controlled by a driving circuit 25 through a reel position compensation control means C, a tape traveling driving means D, etc. in the circuit 24 so that the stored contents coincide with a reel current position detected by the means B at the loading end detected by a composite photographing detecting circuit 23. Consequently, recording is prevented from overlapped recording or the lack of a picture, and composite photographing can be precisely attained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing apparatus for image information such as a VTR, and more particularly to a magnetic recording and reproducing apparatus that performs unloading and loading during splicing (editing).

For example, in a helical scan type magnetic recording and reproducing apparatus, a loading operation is performed to wind a video tape around a drum equipped with a video head, and an unloading operation is performed to separate the video tape from the drum.

Generally, during loading, the supply reel and take-up of the cassette tape are
Apply the brake on one of the reels, for example the pick-up reel, pull out the videotape from the reel and wind it onto the drum.The same operation is also performed when unloading, and loading and unloading are repeated. At all costs, the relative positions of the video tapes should not shift too much.

Therefore, after recording is finished, when recording is started from the next video track after the last video track where recording has been completed, it is possible to connect relatively accurately even if unloading and loading are performed.

By the way, providing a mechanism that applies a brake to the reel during loading and unloading in this way
This increases the complexity of the tape loading mechanism.

Therefore, such a brake mechanism was omitted.

A mechanism that does not apply brakes to either the supply reel or the pick-up reel during loading and unloading may be considered.

However, when loading and unloading is performed with the two reels free in this manner, the position of the videotape shifts due to loading and unloading, resulting in a problem that accurate splicing cannot be performed.

1-] Summer This invention was made in view of the above points, and in particular, even if it is a magnetic recording and reproducing device in which two reels are made free during loading and unloading,
To enable accurate continuous shooting without causing double recording or missing images.

Therefore, as shown in FIG. 1, the magnetic recording and reproducing apparatus according to the present invention uses the reel position at the time of unloading start stored in the reel position storage means and the reel position detected by the reel position detection means B. Based on the current position, the reel position correction control means C controls the tape running drive mechanism to match the current reel position at the end of loading with the reel position stored in the reel position storage means. be.

1. Hereinafter, embodiments of the present invention will be described with reference to FIG. 2 and subsequent figures of the accompanying drawings.

2 and 3 are plan views showing different operating states of the tape loading mechanism of the magnetic recording/reproducing apparatus embodying the present invention.

To briefly explain the operation of this tape loading mechanism, first, as shown in FIG. Loading posts 5 and 6, respectively, were installed in the loading posts 5 and 6. A tension arm 7 is housed inside the video tape 1A of the cassette 1.

If you operate the play lever (PLAY) in this state,
As shown in FIG. 3, the loading arms 3 and 4 rotate and their loading posts 5°6
While pulling out each arrow A.

The tension arm 7 moves in the direction of arrow B, and at the same time, the tension arm 7 also moves in the direction of arrow C.

At this time, the supply reel 1B and take-up reel 1C of the cassette 1 are in a free state, and rotate as the videotape 1A is pulled out.

Next, supply side and winding side impedance rollers 8, 9
, the full-width erasing head 10 moves toward the rotary head cylinder 11, and the supply side and take-up side opening lock arms 12.13 are moved to the arm stopper 14. Loading arm 3, 4 to Is
are locked respectively, loading is completed, and the state shown in FIG. 3 is reached.

In both figures, 16 is a sound erasing head, 17 is a sound control head, and 18 is a pinch roller.

1st is a start sensor, and 20 is an end sensor.

FIG. 4 is a block diagram showing the main parts of the control section of this magnetic recording and reproducing apparatus.

In the same figure, the reel rotation sensor 21 includes, for example, a slit disk in which double slits are formed with a 90° phase shift that moves simultaneously with the rotation of the reel holder that receives the supply reel IB in FIG. It consists of a photosensor that faces each other across a slit in a disc, and outputs position pulses FA and pH according to the rotation of the reel 1B 6. Note that this reel rotation sensor 1 may be configured with, for example, a ball sensor or the like. .

The recording end detection circuit 22 outputs a recording end detection signal SA when a stop button or the like is operated and recording ends.

The continuous shooting detection circuit 23 detects the continuous shooting signal s when the recording button is operated and the continuous shooting start switch is activated.
Output n.

The control circuit 24 is a circuit that also serves as the reel position storage means Δ, the reel position detection means B, and the reel position correction control means C in FIG. 1, and includes, for example, a CPU (central processing unit), a program memory (ROM), and a data memory. It consists of a microcomputer consisting of RAM (RAM) and I10 (input/output device).

This control circuit 24 inputs position pulses FA and pn from the reel rotation sensor 21, recording end detection signal SA from the recording end detection circuit 22, continuous shooting detection signal SB from the continuous shooting detection circuit 23, etc. R
Processing is performed based on the program stored in the OM, and the reel drive motor 26 is rotationally driven via the drive circuit 25.

Next, the effect of this embodiment in which t1η is formed in this way will be explained in the fifth section.
This will be explained with reference to the figures and FIG.

First, during continuous shooting, by operating the stop button, the recording end detection circuit 22 inputs the recording end signal (+1 SA) to the control circuit 24, and the tape loading control system (not shown) causes the tape loading mechanism to Unloading is started to return the state from the state shown in FIG. 3 to the state shown in FIG. 2.

When the recording button is operated after unloading is completed, the continuous shooting detection No. 41 SR is input from the continuous shooting detection circuit 23 to the control circuit 24, and the tape loading mechanism is activated by the tape loading control system as shown in FIG. Loading is performed from the state shown in FIG. 3 to the state shown in FIG.

When unloading and loading these.

As described above, the supply reel lu and take-up reel 1C of the cassette 1 are in a free state.

It rotates as the videotape IA is drawn out and stored.

The operation of the control circuit 24 during unloading and loading will be explained with reference to FIGS. 5 and 6.

First, with reference to FIG. 5, when the recording end detection signal SA is inputted from the recording end detection circuit 22, that is, when unloading is started, the control circuit 24 outputs a position pulse PA from the reel rotation sensor 21 at that time. , PB are saved at a predetermined address CNE in the RAM.

After that, the control circuit 24 checks whether the position pulse PA or PR from the reel rotation sensor 21 is input, and if the position pulse PA or pB is input, the control circuit 24 checks which of the 1 position pulses pA and PR is input. It is determined whether or not the rotation direction of the reel 1B is in the forward direction.

As a result of this determination, if the rotation direction of the reel 1B is the forward direction, the count value of the counter CN is incremented (+1
)do.

On the other hand, if the rotation direction of the reel 1B is not in the forward direction, that is, in the reverse direction (rewind direction), the count value of the counter CN is decremented (-1).

Then, it is determined whether or not the loading has ended, and the counter CN is incremented (+1) or decremented by l-, (-1) in accordance with the input of the position pulses PA and PR as described above until the loading is completed.

That is, as described above, the amount of rotation of the reel 1B from the position at the start of unloading is counted from the time when unloading is started until the next loading is instructed and loading is completed.

When loading is completed, it is determined whether or not the continuous shot signal 3n from the continuous shot detection circuit 2!1 is input.

As a result of this determination, if the continuous shooting signal 5B is input, as shown in FIG. It is determined whether the values match (CN lc = ON), that is, whether the reel 1B has not rotated from the position at the start of unloading.

As a result of this determination, if CNE=CN, the wheel 1E has not rotated from the position at the start of unloading, so
The process moves directly to recording start processing.

On the other hand, if CNE=CN, reel IB has rotated from the position at the start of unloading, so next check whether CN E<CN, that is, reel 1B is rotating forward from the position at the start of unloading. Determine whether it is rotating.

As a result of this determination, if CNE<CN, the reel 1U is rotating in the forward direction from the position at the start of unloading. position pulse PA or Pll
The count value of the counter CN is decremented (-1) every time the value is input.

On the other hand, if CNE<CN, the reel IB is rotating in the opposite direction from the position at the start of unloading, so the reel drive upper 26 is controlled to rotate the reel 1B in the forward direction. Let me.

Every time the position pulse PA or PB is input, the counter CN
The count value of is incremented (+1).

Then, these processes are repeatedly executed until CNE=CN, that is, until the current position of reel 1B matches the position at the start of unloading stored in address CNE of RAM. As before, proceed to the recording start process.

Therefore, recording is started from the position on the videotape following the position on the videotape at the end of the previous recording.

In this way, this magnetic recording/reproducing device stores the position of the reel at the start of unloading, detects the current position of the reel, and rotates the reel by the amount rotated by unloading and loading at the end of loading. Rotate to match the current position of the reel with the position at the start of unloading.

As a result, since recording is started from the position immediately after the recording position at the end of recording, double recording and missing images do not occur.

In the above embodiment, the reel position is corrected only at the end of loading, but the reel position may also be corrected at the end of unloading.

In addition, unlike the magnetic recording and reproducing apparatus of the above embodiment, a magnetic recording device equipped with a tape loading mechanism that brakes either one of the reels during unloading and loading without leaving either the reel on the supply side or the take-up side free. In a recording/reproducing apparatus, if the brake is working reliably, continuous shooting can be performed almost accurately, but if the brake is not working properly, the position of the tape will shift and accurate continuous shooting will not be possible.

Therefore, if the present invention is implemented in such a magnetic recording/reproducing device, it will be possible to accurately continue shooting even when the brake effectiveness becomes poor.

As explained above, according to the present invention, in particular, in a magnetic recording and reproducing apparatus equipped with a tape loading mechanism in which both the reel on the supply side and the reel on the take-up side are free during unloading and loading, Even when unloading and loading, it is possible to accurately perform continuous shooting without causing double recording or missing images.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention, and FIG.
3 and 3 are plan views showing different operating states of the tape loading mechanism of the magnetic recording/reproducing apparatus embodying the present invention. FIG. 4 is a block diagram of main parts showing an example of the control section. 5 and 6 are flowcharts showing an example of the operation of the control circuit of FIG. 4. FIG. 1...Cassette 1Δ...Video tape 1B...
Supply side reel IC... Winding side reel 5.6... Loading post 8.9... Impedance roller 11... Rotating head cylinder 21... Reel rotation sensor 22... Record end detection circuit 23・・・Sequential shot detection circuit

Claims (1)

[Claims] 1. In a magnetic recording and reproducing device that performs unloading and loading during splicing, reel position storage means stores the position of the reel loaded with video tape at the time of start of unloading, and reel position detection means detects the current position of the reel. Then, the tape running drive mechanism is controlled based on the stored reel position stored in the reel position storage means and the current reel position detected by the reel position detection means, so that the current reel position at the end of loading is set to the stored reel position. 1. A magnetic recording and reproducing apparatus comprising: reel position correction control means for matching reel positions.