JPH10208203A - Video tape recorder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a VTR device realizing both functions of the total width erase function and CTL pre-read function without substantially increasing the number of components. SOLUTION: When a recording mode of total width erase is instructed, a switch 21 is changed over to a terminal (a) by the control of a control part 27 so that a FE head 11 for total width erase is functioned as the total width erase head, and the erase current from an erase current impressing circuit 22 is impressed on the FE head 11 through the switch 21. When a recording mode of CTL pre-read is instructed, the switch 21 is changed over to a terminal (b) so that the FE head 11 is functioned as the CTL pre-read head, then the decision is made through from an amplifier circuit 23 to a signal detecting circuit 26 inclusive whether the signal is being recorded on the video tape 31 or not, and the result of this decision is outputted to the host control part through the control part 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a video tape recorder having a TL pre-read function.

[0002]

2. Description of the Related Art Commercial video tape recorders (hereinafter referred to as VTRs) used in television broadcasting stations and the like, for example, used in the final step of a production site, require new video data. When recording, if any video signal is already recorded on the video tape, do not record a new signal,
In other words, there is a case in which a function of always recording a new video signal in an area where nothing is recorded is required.

In order to realize such a function, it is necessary to overwrite the recording of a new signal or to check whether any signal is recorded in the area before erasing the recorded signal. There is a need to. To this end, conventionally, a signal at a position corresponding to a control track of the video tape is read, and it is checked whether or not a control signal is recorded on the track, so that a signal is already recorded on the video tape. A method of checking whether or not the answer is yes is used. Such a function of reading the control track in advance and checking for the presence or absence of the recording signal is called a CTL pre-read function.

[0004]

However, if the conventional VTR device is to have both the full width erasing function and the CTL pre-read function, the full erase head (full width erasing head) on the front side of the drum is required. , FE heads), and before the normal CTL heads at positions where those heads are provided, a C for pre-reading is further provided.
It was necessary to provide a TL head. Therefore, in such a VTR apparatus, since three heads are required, there is a problem that the number of parts increases and the cost of the VTR apparatus increases. In addition, there is a danger that the possibility of failure as a device increases due to an increase in the number of parts and a complicated structure. Furthermore, having to accommodate such three heads is
There is also a problem that it becomes an obstacle to miniaturization of the device.

Accordingly, it is an object of the present invention to provide a VTR device which realizes both the full width erasing function and the CTL pre-read function without substantially increasing the number of components.

[0006]

In order to solve the above-mentioned problems, a CTL pre-read function is realized by using an FE head. That is, by using the FE head for the CTL pre-read by switching the mode, the FE head of the conventional VTR apparatus has the full width erasing function and the CTL head.
Both functions of the pre-read function are provided so that the number of parts does not substantially increase.

Therefore, the VTR apparatus of the present invention has a first mode in which a new video signal is not recorded when a signal is already recorded on a video tape, and a new mode irrespective of the recording state of the signal on the video tape. A video tape recorder device having a second mode for recording a video signal, and recording a video signal input based on a set mode, wherein the video tape recorder device has a gap width corresponding to the entire width of the video tape. A magnetic head provided before the recording head that records a video signal on the video tape, and when the first mode is set, based on a signal detected from the video tape by the magnetic head, Signal detecting means for detecting whether or not a signal is recorded on a predetermined track in the longitudinal direction of the video tape;
An erase current generating means for generating a predetermined erase current capable of erasing the full width of the video tape by the magnetic head when the mode is set; and the magnetic head and the signal when the first mode is set. Switching means for substantially connecting the magnetic head and the erasing current generating means when the second mode is set; and switching means for substantially connecting the magnetic head and the erase current generating means when the second mode is set. On the basis of the detection result of the signal by the signal detection means, only when the signal is not recorded on the video tape, the input video signal is recorded by the recording head at the relevant portion of the video tape, When the second mode is set, the input video is recorded on the video tape from which the signal has been erased by the erase current generated by the erase current generating means. And a video signal recording means for sequentially recording by the recording head No..

[0008] Preferably, the signal detection means transmits a control signal to a control track of the video tape based on a signal detected from the video tape by the magnetic head having a gap corresponding to the entire width of the video tape. It detects whether or not it is recorded.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, V of the present embodiment
A state in which a video cassette tape is mounted on a TR device and its VTR device will be described with reference to FIG. FIG. 1 is a diagram showing a state of a tape traveling system when a video cassette tape is mounted on the VTR device of the present embodiment. The VTR device 10 includes a FE head 11, a CTL head 12, a drum 13, a threading ring 14, a supply-side drawer arm (S drawer arm) 15, and a take-up-side drawer arm (T drawer arm) as components related to the running of the video tape 31. ) 16.

Then, the video cassette tape 30 is
When the video tape 31 is attached to the R device 10, the video tape 31 is pulled out by the S pullout arm 15, the T pullout arm 16 and the threading ring 14, and is wound around the drum 13. Thus, the FE head 11 and the CTL according to the present invention provided in front of the drum 13 are provided.
The head 12 comes into contact with the video tape 31. In FIG. 1, the direction dt of the arrow indicates the running direction of the video tape 31 in a normal reproducing / recording operation.

Next, a signal processing section related to the FE head 11 of the VTR device 10 will be described with reference to FIGS. FIG. 2 is a block diagram illustrating a configuration of a signal processing unit related to the FE head 11 illustrated in FIG. Signal processing unit 20
Is a switch 21, an erase current application circuit 22, an amplification circuit 2
3, an LPF 24, a detection circuit 25, a signal detection circuit 26, and a control unit 27.

The switch 21 switches a circuit connected to the coil of the FE head 11 based on a switching signal from the control unit 27. When the FE head 11 is used as a full-width erasing head, the terminal a is selected as the switch 21 and the erasing current output from the erasing current applying circuit 22 is set to F.
Applied to the E head 11. Also, the FE head 11 is
When the switch 21 is used as a TL pre-read head, the terminal b is selected for the switch 21, and a signal detected by the FE head 11 is input to the amplifier circuit 23.

The erasing current application circuit 22 includes the FE head 11
Is used as a full-width erase head, the FE head 11
, A signal for erasing the signal recorded on the video tape 31 is applied. When the FE head 11 is used as a CTL pre-read head, the amplifier circuit 23 amplifies a signal detected by the FE head 11 and input through the switch 21.

The LPF 24 extracts only a predetermined low-frequency component from the signal amplified by the amplifier circuit 23, and
5 is output. The detection circuit 25 detects a signal input from the LPF 24, extracts a control signal, and outputs the control signal to the signal detection circuit 26. The signal detection circuit 26 determines whether any significant signal is recorded on the video tape 31 based on the detection result input from the detection circuit 25, and outputs the determination result to the control unit 27.

The control section 27 controls each section of the signal processing section 20 based on a control signal from a higher-order control section.
In particular, during a video data recording operation, a first recording mode in which a higher-level control unit overwrites the control unit 27 with a new signal that is always input even if any signal is recorded on the video tape 31; If any signal is recorded, a second recording mode in which recording is not performed at that location but only at a location where nothing is recorded is instructed.

The control section 27 controls each section of the signal processing section 20 so that the FE head 11 functions as a full-width erasing head when the first recording mode is instructed. That is, a switching signal for selecting the terminal a is applied to the switch 21, a current for erasing the signal recorded on the video tape 31 is generated for the erasing current application circuit 22, and the current is generated for the FE head 11. Instruct to output. Further, when the second recording mode is instructed to the control unit 27, each unit of the signal processing unit 20 is controlled so that the FE head 11 functions as a CTL pre-read head.
That is, a switching signal for selecting the terminal b is applied to the switch 21, and as a result, the amplification circuits 23 to
A signal for determining whether or not a signal has been recorded on the video tape 31 detected by the signal detection circuit 26 is output to a higher-level control unit.

Here, the signal recording format on the video tape 31 of the video cassette tape 30 mounted on the VTR device 10 will be described with reference to FIG. VTR
The apparatus 10 is a so-called HDCAM video tape recorder, and its recording format is as shown in FIG. That is, a time code track and a control track are provided in parallel with the longitudinal direction of the video tape 31 from a tape reference edge on the lower side of the video tape 31, and a cue audio track is provided on an edge of the video tape 31 opposite to the track. A truck is provided. And between those tracks, its longitudinal track and about 4.6
A helical track having digital video and digital audio areas at an angle of ° is provided. In FIG. 3, the arrow dt indicates the tape running direction,
Arrow dh indicates the head traveling direction.

Next, the operation of the VTR 10 will be described. As described above, in the VTR device 10, the signal recording operation modes include a first recording mode in which a new signal is overwritten even if the video tape 31 to be recorded has already been recorded, and an old recording mode. There is a second recording mode in which recording is kept, and recording is always performed only on the part of the permanent recording. Instructions for these recording modes are issued from a higher-level control unit (not shown) to the control unit 27 of the signal processing unit 20.

When the first recording mode is instructed, the switch 21 is switched to the terminal a under the control of the control unit 27 so that the FE head 11 functions as a full-width erasing head. The erase current from 22 is applied to the FE head 11 via the switch 21. Also, when the second recording mode is instructed, F
The switch 21 is switched to the terminal b so that the E head 11 functions as a CTL pre-read head, and it is determined whether or not a signal has been recorded on the video tape 31 detected by the amplifier circuit 23 to the signal detection circuit 26. The signal is output to a higher-level control unit via the control unit 27.

In this embodiment, since the FE head 11 has a gap in the entire width, there is a problem that all signals on the video cassette tape 30 are picked up. The fact that the control signal recorded on the control track can be appropriately read out by the FE head 11 will be described with reference to FIGS. Since the data recorded on the helical track is detected only as noise in the FE head 11, the description will be made here using the case where the signal is recorded on the time code track, control track, and cue audio track. Do.

FIG. 4 is a diagram showing amplifier noise in the amplifier circuit 23, and FIG. 5 is a diagram showing a reproduced signal detected from a video tape on which no signal is recorded.
FIG. 6 is a diagram showing a reproduction signal detected from a video tape on which signals are recorded on a time code track, a cue audio track, and a control track. FIG. 7 shows a case where a signal is recorded only on a control track. FIG. 4 is a diagram showing a reproduction signal detected from a video tape in use. Note that a 1 kHz analog audio signal is recorded on the cue audio track of the video tape whose reproduction signal is shown in FIG.

As shown in FIG. 5, if no signal is recorded on the video tape, the detected reproduced signal is as shown in FIG.
4 are only the amplifier noise and the sliding noise of the video tape shown in FIG. Then, a reproduction signal as shown in FIG. 6 is obtained from a video tape on which signals are recorded on the time code track, the cue audio track, and the control track. When this reproduced signal is compared with a reproduced signal detected from a video tape in which a signal is recorded only on the control track shown in FIG. 7, it can be clearly seen that the main components match. In other words, it can be seen that the control signal can be properly detected even if the video tape on which signals are recorded on the time code track, the cue audio track, and the control track is reproduced by the FE head 11 having a gap in the entire width.

This is because the control signal has a lower frequency than other recording signals, and the control signal is recorded with a saturation magnetic flux, that is, recorded at a higher level than the other signals. by. Therefore, if the frequency band of the control signal is further extracted by the LPF 24 or the like as in the present embodiment, the control signal can be detected more reliably. Therefore,
In such an FE head 11, the video tape 31
It is possible to reliably check whether or not a signal has been recorded in the.

As described above, the VTR device 1 of the present embodiment
In the case of 0, the FE head 11 is used for two functions of full-width erasing and CTL pre-read by mode switching, thereby supporting two modes without increasing the number of components. That is, at the time of signal recording, the video tape 3
1 is a first recording mode in which a new signal that is always input is overwritten even if some signal is recorded, and if any signal is recorded, nothing is recorded without recording at that position The second recording mode in which recording is performed only at a location can be performed, and as a result, the VTR apparatus 10 has high performance, is low in cost, and has few troubles.

The present invention is not limited to the present embodiment, and various modifications are possible. For example, in the VTR device 10 of the present embodiment, the control signal recorded on the control track of the video tape 31 is detected, and it is determined whether or not the signal is already recorded on the video tape 31. However, such a determination may be made by detecting a signal recorded on another time code track or cue audio track, for example. In this case, it is preferable to change the LPF 24 of the signal processing unit 20 shown in FIG. 2 to a band-pass filter (BPF) corresponding to the signal recorded on the track. By doing so, the signal recorded on each track can be properly detected.

In this embodiment, it is assumed that video data is recorded on a video tape in a format as shown in FIG. 3, so that signals of a time code track, a cue audio track and a control track are detected. It was taken. However, the present invention is not limited to the recording format of the video tape at all, and includes D-1, D-2, D-5, D-6, DVCPR.
O, Betacam SX, Digital Betacam, Digital S, DVC-SD, D5-HD, DVC-HD, etc., are compatible with video tapes and VTR devices recorded in any standard format. Also, the shape and configuration of the FE head, the specific configuration of the VTR device, etc.
Any suitable changes may be made.

[0027]

As described above, according to the present invention,
Full width erase function and C without substantially increasing the number of parts
A VTR device that realizes both functions of the TL pre-read function can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state of a tape running system when a video cassette tape is mounted on a VTR device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a signal processing unit of the FE head shown in FIG.

FIG. 3 is a diagram illustrating a signal recording format on a video tape of a video cassette tape mounted on the VTR device shown in FIG. 1;

FIG. 4 is a diagram showing amplifier noise in the amplifier circuit shown in FIG. 2;

FIG. 5 is a diagram showing a reproduced signal detected from a video tape on which no signal is recorded.

FIG. 6 is a diagram showing a reproduction signal detected from a video tape on which signals are recorded on the time code track, cue audio track, and control track shown in FIG. 3;

FIG. 7 is a diagram showing a reproduced signal detected from a video tape on which a signal is recorded only on the control track shown in FIG. 3;

[Explanation of symbols]

10 VTR device, 11 FE head, 12 CTL head, 13 drum, 14 threading ring, 1
5 S extraction arm, 16 T extraction arm, 20 signal processing unit, 21 switch, 22 erase current applying circuit,
23 ... amplifying circuit, 24 ... LPF, 25 ... detection circuit, 26
... Signal detection circuit, 27 ... Control unit, 30 ... Video cassette tape, 31 ... Video tape

Claims (2)

[Claims] 1. A first mode in which a new video signal is not recorded when a signal is already recorded on a video tape, and a second mode in which a new video signal is recorded irrespective of a recording state of a signal on the video tape. A video tape recorder device that records a video signal input based on the set mode, having a gap width corresponding to the entire width of the video tape,
A magnetic head provided before the recording head that records a video signal on the video tape, and when the first mode is set, based on a signal detected from the video tape by the magnetic head,
Signal detection means for detecting whether or not a signal is recorded on a predetermined track in the longitudinal direction of the video tape; and when the second mode is set, the entire width of the video tape can be erased by the magnetic head. An erase current generating means for generating a predetermined erase current; when the first mode is set, the magnetic head and the signal detecting means are substantially connected; and when the second mode is set, Switching means for substantially connecting the magnetic head and the erasing current generating means; and when the first mode is set, the video tape is connected to the video tape based on a signal detection result by the signal detecting means. Only when no signal is recorded, the input video signal is recorded by the recording head at the corresponding position on the video tape, and the second mode is set. Case, a video tape recorder and a video signal recording means for sequentially recording the input video signal to the video tape which signal is erased by an erase current by the erasing current generator by the recording head. 2. A control signal is recorded on a control track of the video tape based on a signal detected from the video tape by the magnetic head having a gap corresponding to the entire width of the video tape. 2. The video tape recorder device according to claim 1, wherein whether or not the video tape is being recorded is detected.