JPH05135433A - Device for detecting program searching signal of magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To unify time necessary to detect program searching signal, and simultaneously, to detect the program searching signal with a high accuracy without deviation of program searching. CONSTITUTION:The program searching signal detector of a magnetic recording and reproducing device is provided with a program searching signal detection circuit 12 (VISS detection circuit) and the circuit 12 detects a VISS signal based on the duty cycle of a reproducing control signal reproduced from a video tape 6. Also, a register for counting 11 starting to count the number of capstan FG signals D after detecting a VISS detection signal G is detected and a distance to a desired program searching signal area is calculated by a mode control circuit 22 based on the count value. The rotational speed and the rotational direction of a capstan motor are controlled by the mode control circuit 22 based on the calculated distance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cue signal detecting device for a magnetic recording / reproducing device for magnetic recording / reproducing.

[0002]

2. Description of the Related Art A conventional cue signal detecting device for a magnetic recording / reproducing apparatus (hereinafter, simply referred to as a cue signal detecting device) will be described below with reference to FIGS.

As shown in FIG. 4, a conventional cue signal detecting device runs a video tape 36 at a high speed via a capstan motor 34, and outputs a PBCTL (Play Back Control) signal recorded on the video tape 36. PBCTL
Input is made via the head 43.

The PBCTL signal from the PBCTL head 43 is sent to an amplifier circuit 44, where it is amplified to an appropriate signal level and then supplied to a cue signal detection circuit 37 as a PBCTL signal C. In addition, PBCTL
The head 43 and the amplifier circuit 44 form an input signal circuit 35.

In the cue signal detection circuit 37, a cue signal (hereinafter referred to as VISS signal) is detected based on the duty ratio of the input PBCTL signal C and sent to the mode control circuit 42 as a VISS detection signal G. .. When the VISS detection signal G is input to the mode control circuit 42, the following operation is performed.

For convenience of description, the operation in the FF (fast forward) mode will be described here, but the operation in the REW (rewinding) mode is basically the same, and the detailed description thereof will be omitted. As shown in FIG. 2, when reproducing the information recorded with the third VISS signal, the PBCT
1st VISS signal G, 2nd VIS via L head 43
The S signal G and the third VISS signal G are reproduced in sequence. When the target third VISS signal G is detected, PB
The CTL head 43 has passed the region of the third VISS signal.

Thereafter, the mode control circuit 42 sends a signal A indicating the rotation direction of the capstan motor 34 to the servo control register 41. At this time, the signal B indicating the rotation speed (high speed or low speed) of the capstan motor 34 is also output from the mode control circuit 42 to the servo control register 4.
Has been sent to 1. In the servo control register 41, a servo control signal H is generated based on the signal A and the signal B and sent to the servo circuit 33. In the servo circuit 33,
The video tape 36 is rewound in the reverse direction at high speed based on the servo control signal H (REW mode). A control circuit 32 is composed of the servo control register 41 and the mode control circuit 42.

In the process of rewinding the video tape 36 at a high speed, the third VISS signal G is detected again.
When the target third VISS signal G is detected, the PBC
The TL head 43 has already passed the region of the third cueing signal. Therefore, after the target third VISS signal G is detected, the mode control circuit 42 sends to the servo circuit 33 a servo control signal H based on the signal A for instructing the rotation direction to the positive direction and the signal B for lowering the rotation speed. send.

However, in the REW mode, the third VI
The time required for the video tape 36 to stop running after the detection of the SS signal changes depending on the running speed of the video tape 36 (indicated by a dotted line in FIG. 2 for convenience of description), and is not constant. Therefore, the time required to detect the target VISS detection signal G varies. In order to solve this, when the target VISS signal is not detected within the predetermined time in the REW mode, the mode control circuit 42 sends the signal B for increasing the rotation speed to the servo control register 41 to set the target head. The output signal is detected.

When the cue detection signal G is input to the mode control circuit 42 by the cue signal detection circuit 37, it is confirmed that the target cue signal is detected. The servo control is performed by the servo circuit 33 based on the output of the servo control register 41 until the tape 36 is changed from high speed to low speed by the signal B and the capstan motor 34 becomes stable. As a result, the conventional cue signal detecting device can output a target reproduced image from the position of the cue signal recorded on the video tape 36.

[0011]

However, in the above conventional configuration, the time required from the detection of the target cueing signal G to the stop of the running of the video tape 36 changes depending on the running speed of the video tape 36. .. This not only causes variations in the time until the reproduced image is output, but also when the cueing signal is detected at high speed, the running speed of the video tape 36 before the reproduced image is output. Needs a wait time to stabilize. For this reason, there is a problem that the target reproduced image is output at a position deviated from the position where the image is actually output.

[0012]

In order to solve the above problems, a cue signal detecting device for a magnetic recording / reproducing apparatus of the present invention reproduces a reproduction control signal and a cue signal from a magnetic recording medium. In the cue signal detecting device of the magnetic recording / reproducing device for reproducing information by the following, the following means are taken.

That is, according to the present invention, a driving means for traveling a magnetic recording medium in both forward and backward directions at high speed or low speed, a cue signal detecting means for detecting a cue signal on the basis of a reproduced reproduction control signal, and a reproducing means. Measuring means for measuring the distance from the current position of the means to the position of the target cueing signal,
When the target cueing signal is detected, the driving means is stopped, the driving means is caused to run the magnetic recording medium in the reverse direction, and when the target cueing signal is detected again, a stop command is given to the driving means. At the same time, the measuring means starts the measuring operation, and after the magnetic recording medium stops, the distance to the position of the cueing signal is calculated based on the output from the measuring means, and when the distance is equal to or more than a predetermined value, the magnetic recording The recording medium is provided with a control means for causing the medium to travel at a high speed in the positive direction and at the same time to cause the magnetic recording medium to travel at a low speed in the positive direction when the distance is smaller than a predetermined value.

[0014]

According to the above construction, when the target cueing signal is detected, the reproducing means passes through the area where the cueing signal exists, but the control means drives the driving means to drive the magnetic field. The recording medium is run in the opposite direction. When the target cueing signal of the area that has passed through is detected again by the cueing signal detecting means, the driving means stops traveling of the magnetic recording medium according to a command from the control means, and The measuring operation is started.

Based on the stop command from the control means,
Eventually, the magnetic recording medium stops running. At this time, the control means calculates the distance from the current position of the reproducing means to the position of the target cueing signal based on the output from the measuring means.

When the distance calculated by the control means is equal to or greater than the predetermined value, the magnetic recording medium runs at a high speed in the forward direction. The information is played back after detection.
On the other hand, when the distance calculated by the control means is smaller than the predetermined value, the magnetic recording medium is immediately run in the forward direction at a low speed, and the information is reproduced after the cueing signal is detected. As a result, the time required to detect the cueing signal can be made uniform.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

As shown in FIG. 1, a cue signal detecting device (hereinafter, simply referred to as a cue signal detecting device) of the magnetic recording / reproducing apparatus according to the present embodiment, as shown in FIG. A signal input circuit 5 for inputting information, a cue signal detection circuit 12 (cue signal detection means), a capstan motor 4 (driving means) for running the video tape 6, and a servo circuit 3 for servo-controlling the capstan motor 4. Counting register 11 (measuring means) and servo circuit 3
And a mode control circuit 22 for controlling the counting register 11 and. The mode control circuit 22 and the servo control register 21 are used to control the control circuit 2
(Control means) is configured. Examples of the magnetic recording / reproducing device include a VTR (Video Tape Recorder) capable of recording and reproducing a television signal and the like.

The signal input circuit 5 outputs the outputs of the PBCTL head 53 (reproducing means) for reproducing the PBCTL (Play Back Control) signal (reproduction control signal) recorded on the video tape 6 and the PBCTL head 53 to appropriate levels. Amplifier circuit 54 that amplifies to a capstan FG
It has a head 51 (reproducing means) and an amplifier circuit 52 for amplifying the output of the capstan FG head 51 to an appropriate level.

The signal reproduced through the PBCTL head 53 is amplified by an amplifier circuit 54, and then, as a PBCTL signal C, a cue signal detection circuit (hereinafter referred to as VISS (VHS
(Index Searching System) (referred to as a detection circuit) 12 is output. In the VISS circuit 12, the input PBCTL
Based on the duty ratio of the signal C, a cue signal (hereinafter, V
(Referred to as ISS signal) is detected and output to the mode control circuit 22 as a VISS detection signal G.

On the other hand, the capstan FG signal reproduced through the capstan FG head 51 is supplied to the amplifier circuit 52.
After being amplified by, it is output to the counting register 11 as a capstan FG signal D. Count register 1
In 1, the number of pulses of the capstan FG signal D is counted based on the count start instruction from the mode control circuit 22, and the counting result is sent to the mode control circuit 22 as the capstan FG counter value E.

Further, the mode control circuit 22 outputs signals A and B to the servo control register 21 based on the capstan FG counter value E and the VISS detection signal G. The signal A is a signal instructing the rotation direction of the capstan motor 4, and the signal B is a signal instructing the rotation speed (high speed or low speed) of the capstan motor 4.

The servo control register 21 generates a servo control signal H based on the input signals A and B and outputs it to the servo circuit 3. Based on this servo control signal H, servo control of the capstan motor 4 is performed, and running of the video tape 6 (rotation direction, rotation speed, etc.) is controlled.

The cue signal detection operation in the FF (fast forward) mode will be described below with reference to FIG.

First, the PB amplified by the amplifier circuit 54
Based on the CTL signal C, the VISS detection circuit 12
The VISS signal is detected based on the duty ratio of the input PBCTL signal C, and is sent to the mode control circuit 22 as the VISS detection signal G. V in the mode control circuit 22
When the ISS detection signal G is input, the following operation is performed.

As shown in FIG. 2, when reproducing the information recorded with the third VISS signal, the first VISS signal, the second VISS signal and the third VISS signal are sequentially reproduced through the PBCTL head 53. When the target third VISS signal G is detected by the VISS detection circuit 12, the PBCTL head 53 is already in the third VI.
It has passed the area of the SS signal.

Thereafter, the mode control circuit 22 instructs the capstan motor 4 to rotate in the reverse direction (signal A).
Is sent to the servo control register 21. At this time, the mode control circuit 22 also sends an instruction (signal B) for increasing the rotation speed of the capstan motor 4 to the servo control register 21 at the same time. In the servo control register 21, a servo control signal H is generated based on the signal A and the signal B and sent to the servo circuit 3, and the video tape 6 is rewound at a high speed in the reverse direction based on the servo control signal H ( REW mode).

In the process of rewinding the video tape 6 at a high speed, the third VISS signal G is detected again, but when the target third VISS signal G is detected, the PBCT is detected.
The L head 53 has already passed the region of the third VISS signal. Simultaneously with the detection of the target third VISS signal G again, the counting of the capstan FG signal D is started in the counter register 11 by the instruction to start counting from the mode control circuit 22, and the servo control signal H is used. Then, an instruction to stop the running of the video tape 6 is given, and the running of the video tape 6 is stopped after a predetermined time.
Hereinafter, this operation is referred to as a correction operation.

The mode control circuit 22 confirms that the running of the video tape 6 is stopped by the capstan FG signal D and fetches the capstan FG counter value E. This capstan FG counter value E is the third VISS signal G
It corresponds to the distance that the video tape 6 has moved from the detection of 1 to the stop of the video tape 6. Mode control circuit 2
2 calculates the distance [centimeter] corresponding to one pulse of the capstan FG based on the standard value of the capstan motor 4.

As a result of the distance calculation, the PBCTL head 53
Is close to the third VISS signal (the calculated distance is small), the rotation direction of the capstan motor 4 is changed to the forward direction together with an instruction (signal B) to reduce the rotation speed of the capstan motor 4. An instruction (signal A) to perform is given from the mode control circuit 22 to the servo control register 21.

On the other hand, the PBCTL head 53 is the third VIS
If it is not near the S signal (the calculated distance is large), an instruction to increase the rotation speed of the capstan motor 4 (signal B) and an instruction to set the rotation direction of the capstan motor 4 to the positive direction ( The signal A) is given from the mode control circuit 22 to the servo control register 21. As a result of the video tape 6 running at high speed in the forward direction, PBCTL
When the head 53 comes close to the third VISS signal, the mode control circuit 22 gives an instruction (signal B) to the servo control register 21 to lower the rotation speed of the capstan motor 4 in the same manner as described above.

Therefore, in REW mode, the third VIS
After the second detection of the S detection signal G is completed, the time required for the video tape 6 to stop running is substantially constant without depending on the running speed of the video tape 6. Therefore, the time required to detect the target cueing signal does not vary.

When the mode control circuit 22 receives the third VISS detection signal G, a target reproduced image is output from the position of the cueing signal recorded on the video tape 6.

When the VISS signal detection operation is not in progress or before the correction operation, the capstan FG count preset value F is set from the mode control circuit 22 to the counter register 1
Sent to 1. As a result, the counter register 11 is always in the preset state.

Now, with reference to FIG. 3, an operation for detecting a cue signal in the REW (rewind) mode will be described below.

FIG. 3 shows a case where the information recorded with the first VISS signal is reproduced. The REW operation is started from the right side in the drawing, and the first VI is started from the third VISS signal.
After being reproduced by the PBCTL head 53 toward the SS signal, it is output to the VISS detection circuit 12 as the PBCTL signal C via the amplifier circuit 54.

PBCTL amplified by the amplifier circuit 54
Based on the signal C, the VISS detection circuit 12 detects the first to third VISS signals based on the duty ratio of the input PBCTL signal C, and the first to third VISS signals are detected.
The detection signal G is sent to the mode control circuit 22. Then, when the VISS detection signal G is input to the mode control circuit 22, the following operation is performed.

As shown in FIG. 3, in the process of rewinding the video tape 6 at a high speed, the target first VISS detection signal G is detected again by the VISS detection circuit 12.
When the target first VISS detection signal G is detected, P
The BCTL head 53 has already passed the area of the first VISS signal. At this time, simultaneously with the detection of the target first VISS detection signal G, the count of the capstan FG signal D is started in the counter register 11 by the instruction to start counting from the mode control circuit 22, and the servo control signal H is used. Then, an instruction to stop running the video tape 6 is given, and the running of the video tape 6 is stopped after a predetermined time (correction operation).

The mode control circuit 22 confirms that the running of the video tape 6 is stopped by the capstan FG signal D and fetches the capstan FG counter value E. The capstan FG counter value E corresponds to the distance the video tape 6 has moved from the detection of the third VISS detection signal G until the video tape 6 is stopped, and the mode control circuit 22 causes the capstan FG counter value E to be the same as described above. A distance [centimeter] corresponding to one pulse of the stun FG is calculated.

When the PBCTL head 53 is located in the vicinity of the first VISS signal (the calculated distance is small), the capstan motor 4 is instructed to make the rotation speed of the capstan motor 4 low (signal B). An instruction (signal A) for setting the rotation direction to the forward direction is given from the mode control circuit 22 to the servo control register 21.

On the other hand, the PBCTL head 53 is the first VIS
If it is not near the S signal (the calculated distance is large), an instruction to increase the rotation speed of the capstan motor 4 (signal B) and an instruction to set the rotation direction of the capstan motor 4 to the positive direction ( The signal A) is given from the mode control circuit 22 to the servo control register 21. As a result of the video tape 6 running at high speed in the forward direction, PBCTL
When the head 53 comes close to the first VISS signal, the mode control circuit 22 gives an instruction (signal B) to the servo control register 21 to reduce the rotation speed of the capstan motor 4 in the same manner as described above.

Therefore, the time required for the video tape 6 to stop running after the first VISS detection signal G is detected again is substantially constant without depending on the running speed of the video tape 6. Therefore, the time required to detect the target cueing signal does not vary.

When the mode control circuit 22 receives the first VISS detection signal G, the target reproduced image is output from the position of the cue signal recorded on the video tape 6.

When the VISS signal detection operation is not in progress or before the correction operation, the capstan FG count preset value F is set from the mode control circuit 22 to the counter register 1
Sent to 1. As a result, the counter register 11 is always in the preset state.

As described above, the cue signal detecting device of this embodiment is provided with the counting register 11 capable of measuring the distance from the detection of the VISS signal during the correction operation to the stop of the running of the video tape 6. Since the video tape 6 runs at high speed or low speed based on the measured distance, the target VISS signal can be detected within a substantially uniform time. At this time, when the target VISS signal is detected at low speed, the reproduced image is immediately output. Therefore, the accuracy of VISS signal detection can be improved.

[0046]

As described above, the cue signal detecting device of the magnetic recording / reproducing apparatus according to the present invention provides the driving means for traveling the magnetic recording medium at high speed or low speed in both forward and backward directions and the reproduced reproduction control signal. A cue signal detecting means for detecting a cue signal based on the measuring means, a measuring means for measuring a distance from the current position of the reproducing means to a position of the target cue signal, and a driving means when the target cue signal is detected. Stop the means,
After the magnetic recording medium is made to run in the opposite direction to the driving means and the target cueing signal is detected again, a stop command is given to the driving means and at the same time the measuring means is caused to start the measurement operation, and after the magnetic recording medium is stopped Calculating the distance to the position of the cueing signal based on the output from the measuring means and running the magnetic recording medium at high speed in the forward direction when the distance is equal to or greater than a predetermined value, while the distance is smaller than the predetermined value. In this case, the magnetic recording medium is provided with a control means for running the magnetic recording medium at a low speed in the forward direction.

Therefore, when the magnetic recording medium is run in the reverse direction and the cueing signal is detected again, the measurement by the measuring means is started, and the head is moved from the stop position of the reproducing means based on the output of the measuring means. Since the distance to the position of the output signal can be calculated, the time required to detect the output signal can be made uniform.

Further, unlike the conventional case, it is not necessary to run for a certain time until the information is reproduced after the cue signal is detected, so that the cue deviation does not occur and the cue signal can be detected with high accuracy. The effect is played together.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of a configuration of a cue signal detection device of a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 illustrates both the present invention and a conventional example,
It is explanatory drawing which shows the cue signal detection operation | movement in FF mode.

FIG. 3 is an explanatory diagram showing a cue signal detection operation in a REW mode of the present invention.

FIG. 4 is a block diagram showing a main part of a configuration of a conventional cue signal detection device.

[Explanation of symbols]

 4 Capstan Motor (Drive Means) 6 Video Tape (Magnetic Recording Medium) 11 Count Register (Measurement Means) 12 VISS Detection Circuit (Cue Signal Detection Means) 21 Servo Control Register (Control Means) 22 Mode Control Circuit (Control) Means) 51 Capstan FG head (reproducing means) 53 PBCTL head (reproducing means)

Claims (1)

[Claims] 1. A cue signal detecting device of a magnetic recording and reproducing device for reproducing information from a magnetic recording medium on which a reproduction control signal and a cue signal are recorded, by a reproducing means. Driving means for traveling to the track, cue signal detecting means for detecting a cue signal based on a reproduced reproduction control signal, and measuring means for measuring a distance from the current position of the reproducing means to a target cue signal position. When the target cueing signal is detected, the driving means is stopped, the driving means is caused to run the magnetic recording medium in the reverse direction, and when the target cueing signal is detected again, a stop command is issued to the driving means. At the same time as the measurement, the measuring means starts the measuring operation, and after the magnetic recording medium stops, the distance to the position of the cueing signal is calculated based on the output from the measuring means, and the distance When the magnetic recording medium has a predetermined value or more, the magnetic recording medium runs at high speed in the positive direction, and when the distance is smaller than a predetermined value, the magnetic recording medium runs at low speed in the positive direction. Cue signal detection device for playback device.