JPH06326955A - Video recorder - Google Patents

Abstract

PURPOSE:To shorter or eliminate a video signal recording disabled period after depressing a recording start key. CONSTITUTION:This video recorder is a camcoder having a consective recording function based upon a reproducing servo. An output video signal from a camera part 1 is delayed by an N-frame period through a picture memory 3 and then the delayed signal is supplied to a magnetic head 7 through a frequency modulator 5 and a recording amplifier 6 to record the signal in a magnetic tape 31. At the time of consectively recording N frames by the reproducing servo, the number of frames to be recorded is set up to a value larger than the number of frames to be rewound. When a user specifies the start of recording by rurning on a switch 21, the running of the tape 31 is started under the control of a control circuit 9 and tracking is controlled by means of CRT signals. Simultaneously the CTL signals are counted, and when the count value becomes the same as the number of frames rewound for consective recording, the amplifier 6 is driven to start recording and the video signal delayed by the N-frame period is recorded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video recording apparatus suitable for application to, for example, a camera-integrated VTR capable of continuous shooting by reproducing servo.

[0002]

2. Description of the Related Art Conventionally, a camera-integrated VTR has been proposed which enables continuous shooting by reproducing servo.

First, the capstan and the reel are reversed from the recording start point, the control signal reproduced from the control track on the tape is counted while rewinding the magnetic tape, and when the count value reaches a predetermined value, the tape Stop rewinding and enter the recording standby state.

Next, when performing joint shooting, reproduction is started from the stand-by point, and tracking servo is applied using the control signal reproduced from the control track within the rewinding period, and the data is recorded before. The recorded track is set to be accurately traced. At the same time, recording is started when the count value reaches the same count value as when the control signal is counted and rewound, that is, when the recording start point is reached.

FIG. 4 shows an example of the tape format. Reference numeral 31 is a magnetic tape, and 32 is an inclined recording track formed on the magnetic tape 31 by a rotary magnetic head. PCM audio signals and video signals are recorded on the recording track 32. Reference numeral 33 is a control track in which a control signal is recorded in relation to the position of the recording track 32. The hatched portion of the recording track 32 is a portion newly formed by the joint photographing by the reproduction servo described above. In this case, the interval between the newly formed first recording track 32 and the old recording track 32 adjacent thereto is the same as the interval between the old recording tracks 32.

[0006]

In the above-described joint recording by the reproduction servo, it takes several frame periods from the operation of the recording start button in the recording standby state until the actual recording is started. Therefore, the recording start button There was a problem that the video signal could not be recorded for several frame periods after the operation of.

Therefore, the present invention provides a video recording apparatus capable of reducing or eliminating the non-recordable period of the video signal after the recording start button is operated.

[0008]

According to a first aspect of the present invention, there is provided a video recording apparatus, an image memory for delaying an input video signal for a predetermined time, a recording start operation means for operating recording start, and a recording start operation. And a recording unit for starting recording of the video signal output from the image memory after the recording start is operated by the means and the servo is locked in.

A video recording apparatus according to a second aspect of the invention is
In the invention of claim 1, the predetermined time period is longer than a time period from when the recording start is operated by the recording start operation means until the servo is locked in.

The video recording apparatus according to the invention of claim 3 is
In the invention of claim 1, there is provided means for varying the predetermined time.

A video recording apparatus according to the invention of claim 4 is
In the invention of claim 1, the input video signal is supplied from a video camera.

[0012]

According to the first aspect of the invention, after the recording start is operated by the recording start operation means and the servo is locked in, the recording of the video signal delayed by the predetermined time in the image memory is started in the recording section. When the input video signal is recorded as it is in the recording section, the video signal cannot be recorded during the period from the recording start operation means operating the recording start to the lock-in of the servo. It becomes possible to reduce or eliminate the unrecordable period of the video signal after the recording start is operated by the recording start operation means.

In the second aspect of the invention, the delay time in the image memory is longer than the time until the recording start is operated by the recording start operating means and the servo is locked in. Therefore, the recording start operating means starts the recording. It is possible to eliminate the non-recordable period of the video signal after being operated, and it is possible to record the video signal before the recording start is operated by the recording start operation means.

According to the third aspect of the invention, since the delay time in the image memory can be adjusted by the variable means, the unrecordable period of the video signal after the recording start is operated by the recording start operation means, or the recording start is started. It is possible to adjust the recording period of the video signal before the start of recording is operated by the operating means.

According to the fourth aspect of the invention, the video signal is output from the video camera in real time, but the unrecordable period after the recording start is operated by the recording start operation means of the video signal from the video camera. It can be reduced or eliminated.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. This example is an example of application to the camera-integrated VTR having the above-described joint photographing function by the reproduction servo.

In the figure, reference numeral 1 denotes a camera unit, and a monochrome video signal output from the camera unit 1 is converted into a digital signal by an A / D converter 2 and supplied to an image memory 3 as a writing signal. The video signal read from the image memory 3 is converted into an analog signal by the D / A converter 4, FM-modulated by the FM modulator 5, and then the recording amplifier 6
Is supplied to the rotary magnetic head 7 via the magnetic tape 31.
Is recorded on the inclined recording track 32 (see FIG. 4). The operation of the recording amplifier 6 is performed by the system control circuit 9
Controlled by.

Reference numeral 8 is a clock generation and memory control circuit, the operation of which is controlled by the control of the system control circuit 9. Reference sync signals such as a horizontal sync signal, a vertical sync signal, and a frame signal are supplied from the camera unit 1 to the circuit 8. A / D converter 2 and D / A converter 4 from the circuit 8
Is supplied with a timing pulse such as a sampling pulse, and the circuit 8 controls writing and reading operations of the image memory 3.

The image memory 3 has a storage capacity of (N + 1) frames, and the image memory 3 constitutes a delay circuit having a delay time of N frame periods. In this example, N frames are set to be larger than the number of frames rewound during joint shooting by the reproduction servo.

FIG. 2 shows an outline of the image memory 3.
Each memory section with memory addresses 0 to N is 1
It has a storage capacity for frames. This image memory 3
The control of writing and reading addresses is performed at the timing shown in the figure, and the video signal written in a certain address is read out after N frame periods.

Further, 11 is a capstan servo circuit, and the operation of the servo circuit 11 is controlled by the system control circuit 9. Reference numeral 12 is a capstan motor. A frequency signal from a frequency generator (FG) 13 attached to the rotating shaft of the capstan motor 12 is supplied to a servo circuit 11 via an FG amplifier 14 to form a speed error signal. To be done.

A control head (CTL head) 15 reproduces a control signal from the control track 33 (see FIG. 4) during reproduction. The control signal reproduced by the CTL head 15 is supplied to the servo circuit 11 via the CTL amplifier 16. A frame signal is supplied from the camera unit 1 to the servo circuit 11, and the phase signal is compared with the control signal to form a phase error signal for tracking servo. Then, the servo circuit 11 adds the speed error signal and the phase error signal, and the added error signal is supplied to the motor drive amplifier 17 to control the rotation of the capstan motor 12.

The control signal reproduced by the CTL head 15 is supplied to the system control circuit 9 via the CTL amplifier 16. The control circuit 9 counts the control signal at the time of joint shooting by the reproduction servo.

Further, the system control circuit 9 includes
A connection switch 21 forming a recording start button, a connection switch 22 forming a recording stop button, and a key panel 23 on which various operation keys are arranged are connected.

The operation in the case of performing the joint photographing by the reproducing servo in the above configuration will be described. It is assumed that the magnetic tape has been rewound from the recording start point in advance and is in the recording standby state. At the time of rewinding, the control circuit 9 controls the control track 3 of the magnetic tape 31.
From 3, the control signal reproduced by the CTL head 15 is counted, and the count value is a predetermined value in the recording standby state.

When the user turns on the connection switch 21 at time T ₀ , the control circuit 9 is supplied with a low level signal as its output to instruct the start of recording (shown in FIG. 3A). Along with this, the pinch roller is pressed against the capstan (not shown) by the control of the control circuit 9, and the running of the magnetic tape 31 is started. In the recording standby state, the capstan is in a rotating state.

When the running of the magnetic tape 31 is started, the control signal is reproduced by the CTL head 15 from the control track 33 (shown by the solid line in FIG. 3B). In the servo circuit 11, the control signal and the frame signal (see FIG. 3B
Is compared with that of the broken line) to form a phase error signal, and based on this phase error signal, the rotation of the capstan motor 12 is controlled to perform tracking servo. In this case, the tracking servo is completed before the magnetic tape 31 reaches the recording start point, and the magnetic head 7
Is in a state of accurately tracing the previously recorded recording track.

Simultaneously with the operation of the tracking servo, the control circuit 9 counts the control signal, and when the count value becomes the same as when it is rewound, the magnetic tape 31 is at the recording start point. At the time point T _S , the control circuit 9 supplies a low-level recording control signal to the recording amplifier 6 (the recording control signal is shown in FIG. 3C), and the recording amplifier 6 is activated to record the magnetic tape 31. Recording is started on the track 32.

In this case, from the image memory 3 to the camera unit 1
The supplied input video signal (shown in FIG. 3D) is delayed by N frame periods to output the output video signal (shown in FIG. 3E), and the output video signal is recorded. For example, frame video signals V ₀ , V ₁ , V ₂ , V ₃ , ..., V _N , V from time T _B before N frame periods from time T _{S
N + 1, V N + 2} , when ... are sequentially written in the image memory 3, the frame video signal V ₀ from the time _{T S, V 1, V 2} ,
_{V 3, ···, V N,} V N + 1, V N + 2, ··· are sequentially read from the image memory 3. As a result, the video signal recorded on the magnetic tape 31 from the time T _S is the time T when the user turns on the connection switch 21 to instruct the start of recording.
_The video signal V ₀ is output from the camera unit 1 from time T _B before ₀ .

As described above, in this example, in the joint recording by the reproduction servo, it is possible to record from the video signal before the user turns on the connection switch 21 to instruct the start of recording, and to instruct the start of recording as in the conventional case. It is possible to eliminate the unrecordable period of the video signal after the recording.

In the above embodiment, the video signal is delayed by N frames in the image memory 3, and this N frame is set to be larger than the number of frames rewound at the time of joint recording by the reproduction servo. , N frames may be set equal to or smaller than the number of rewound frames. Even in that case, eliminate the non-recordable period of the video signal after instructing to start recording,
Or there is a benefit that can be reduced.

Further, in the above embodiment, the video signal is delayed by N frames in the image memory 3, but the delay time in the image memory 3 may be variable by operating the key panel 23. . In this case,
It is possible to adjust the unrecordable period of the video signal after the recording start is operated, or the recording period of the video signal before the recording start is operated.

In the above embodiment, the camera unit 1
An example in which a more monochrome video signal is output and the monochrome video signal is recorded has been shown, but the present invention can be similarly applied to an apparatus in which a color video signal is output from the camera unit 1.
In the case of a color video signal, the luminance signal and the color signal are delayed and controlled in the image memory for the same time. Further, when the audio signal is also recorded, which is not described above, the delay control of the audio signal is performed similarly to the video signal.

Further, in the above-mentioned embodiment, the example is applied to the camera-integrated VTR having the joint photographing function by the reproduction servo, but it is similarly applied to the case where the camera section and the VTR section are separate bodies. Of course you can. Further, the present invention can be applied to a device that records an output video signal of a tuner that receives a television broadcast instead of the camera unit. That is, the present invention is suitable for application to recording a video signal from a video signal source that outputs a video signal in real time, and reduces or eliminates a non-recordable period after a recording start is operated. be able to.

Further, although the above-described embodiment is an example in which the present invention is applied to a camera-integrated VTR having a joint photographing function by reproducing servo, the present invention starts recording after the recording start is operated and the servo is locked in. It can also be applied to other video recording devices. In this case, the image memory 3
By making the delay time due to the recording start longer than the time until the servo locks in after the recording start is operated, the unrecordable period of the video signal after the recording start is operated can be eliminated, and further the recording start The video signal before being operated can be recorded.

In the above embodiment, when the digital video signal is output from the camera section 1, the A / D converter 2 can be omitted, while the VTR section after the FM modulator 5 has a digital input. D when possible
The / A converter 4 can be omitted.

[0037]

According to the first aspect of the invention, after the recording start is operated by the recording start operation means and the servo is locked in, the recording unit starts the recording of the video signal delayed by the predetermined time in the image memory. Therefore, it is possible to reduce or eliminate the unrecordable period of the video signal after the recording start is operated by the recording start operation means.

According to the invention of claim 2, the delay time in the image memory becomes longer than the time until the servo is locked in after the recording start is operated by the recording start operation means.
It is possible to eliminate the unrecordable period of the video signal after the recording start is operated by the recording start operation means, and further it is possible to record the video signal before the recording start is operated by the recording start operation means.

According to the third aspect of the invention, since the delay time in the image memory can be adjusted by the variable means, the unrecordable period of the video signal after the recording start is operated by the recording start operation means or the recording is performed. The recording period of the video signal before the start of recording is operated by the start operation means can be adjusted.

According to the fourth aspect of the present invention, the video signal is output from the video camera in real time, but the unrecordable period after the recording start is operated by the recording start operating means for the video signal from the video camera. Can be reduced or eliminated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a video recording device according to the present invention.

FIG. 2 is a diagram showing an outline of an image memory in the embodiment.

FIG. 3 is a timing chart for explaining the operation of the embodiment.

FIG. 4 is a diagram for explaining joint shooting by a reproduction servo.

[Explanation of symbols]

 1 Camera Part 2 A / D Converter 3 Image Memory 4 D / A Converter 5 FM Modulator 6 Recording Amplifier 7 Rotating Magnetic Head 8 Clock Generation and Memory Control Circuit 9 Output Control Circuit 11 Capstan Servo Circuit 12 Capstan Motor 13 Frequency generator 15 Control head (CTL head) 17 Motor drive amplifier 21 Connection switch that constitutes a recording start button 23 Key panel 31 Magnetic tape 32 Inclined recording track 33 Control track

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 5/93 C 4227-5C

Claims (4)

[Claims] 1. An image memory for delaying an input video signal by a predetermined time, a recording start operation means for operating recording start, and the image after the recording start is operated by the recording start operation means and the servo is locked in. A video recording apparatus comprising: a recording unit for starting recording of a video signal output from a memory. 2. The video recording apparatus according to claim 1, wherein the predetermined time is longer than a time until the servo is locked in after the recording start is operated by the recording start operation means. 3. The video recording apparatus according to claim 1, further comprising a variable means for changing the predetermined time. 4. The video recording apparatus according to claim 1, wherein the input video signal is supplied from a video camera.