JPH04196782A - Magnetic video recording and reproducing device - Google Patents

Abstract

PURPOSE:To enhance the operability at recording and to make the size small by operating an operation switch for recording start of a still picture when the operation period of the operation switch is a predetermined period length. CONSTITUTION:An operation switch 9 is a pushbutton switch for video recording start/stop provided usually to a VTR and a discrimination circuit 37 measures the time when the operation switch 9 is depressed. When the measured time is longer than the preset reference time, it is discriminated that the operation is used for starting or stopping of usual video recording and does not output a control signal S1, and when the discrimination time is shorter than the reference time, it is discriminated that the operation is for still picture recording and a control signal S1 is outputted. A memory 8 is operated by the control signal S1 and an output of an encoder circuit 6 by initial one frame after the operation switch 9 is depressed is written in the memory 8 as still picture information. Thus, the size is made small and the convenience of use at recording is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a helical scan type magnetic recording and reproducing device, and in particular, a magnetic recording and reproducing device that is capable of recording continuous moving images and frame-by-frame still images. The present invention relates to a recording/playback device.

[Prior art] Helical scan type magnetic recording/playback device (hereinafter referred to as VT)
R), for example, a VTR called 8mm video.
In this case, a recording track on a magnetic tape is provided with a normal moving image analog recording area by two-head helical scanning, and a Ninor, which is usually called an overlap recording area, on the extension of the track. This is formed by winding a magnetic tape around a rotating head drum by about 220 degrees, and usually records audio PCM signals.

In response to this, there have been proposals to digitally record still image data for one frame (frame or field) in this overlap recording area.
This is described in Publication No. 33367 and the like. Functionally, this allows the camera-integrated VTR to have the functions of a digital electronic still camera in addition to the normal video analog recording function.

In this case, the reproduced still image is digitally recorded, so the image quality deteriorates during the recording and playback process, compared to the case where a normal video recording is performed and the still image is turned into a still image by applying a still operation during playback. There are almost no Further, if one frame is simultaneously read out from the camera sensor, there is no problem such as deterioration of vertical resolution or occurrence of blur due to subject movement.

Therefore, sufficient image quality as a still image can be obtained. With the spread of video printers, users will no longer need to carry both a still camera and a camera-integrated VTR (camcorder). No matter when a user presses a button, still image data corresponding to one push is always recorded on the magnetic tape.

However, providing an operation switch for recording still image data in addition to the operation switch used for normal recording start/stop of the VTR requires space, which makes it difficult to downsize. This is difficult with a VTR with a built-in camera.

Furthermore, an increase in the number of operation switches poses a problem in terms of usability in order not to miss a so-called photo opportunity for a shooting scene that is desired to be recorded as a still image.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing apparatus that has improved operability during recording and can be miniaturized in consideration of the above points.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides means for determining the operation period of an operation switch for starting/stopping recording, and still image data in accordance with the determination result of the means. A means for recording one force is provided.

[Function] The recording start/stop operation switch is a normal operation switch that puts the VTR into the recording state and recording stop state, but when the operation period of this operation switch is a predetermined length of time, the still image Functions as an operation switch for starting recording.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic recording and reproducing apparatus according to the present invention, in which 1 is a microphone, 2 is a microphone amplifier, 3 is a lens barrel, 4 is a solid-state image sensor, and 5 is an A
/D (analog/digital) conversion circuit, 6 is an encoder circuit, 7 is a D/A (digital/analog) conversion circuit, 8 is a frame (or field) memory, 9 is an operation switch, 10 is a changeover switch, 11 is an input terminal,
12 is a viewfinder, 13 is a noise reduction circuit, 14 is an audio signal recording circuit, 15 is a color signal recording circuit,
16 is a luminance signal recording circuit, 17 is an A/D conversion circuit, 18
19 is a changeover switch, 19 is a slide switch, 20 is a data addition circuit, 21 is a buffer memory, 22 is a parallel/serial conversion circuit, 23 is a PCM modulation circuit, 24 is a pilot signal generation circuit, and 25A.

25B is an adder, 26 is a changeover switch, 27 is a recording amplifier, 28 is a switch pulse generator, 29 is a drum motor, 3o is a tack pulse generator, 31 is a drum servo circuit, 32 is a capstan motor, and 33 is a frequency generator. vessel, 3
4 is a capstan servo circuit, 35 is a recording head, 36
3 is a magnetic tape, and 37 is a discrimination circuit.

In this embodiment, it is assumed that the VTR section complies with the 8 mm video standard.

First, the camera section of this embodiment will be explained.

Here, as explained below, processing such as Y color difference conversion and color encoding is performed using digital processing as an example, but this is just an example, and analog processing may also be used. .

In FIG. 1, light passing through a lens barrel 3 forms an optical image on a solid-state image sensor 4. As shown in FIG. As is well known, on this light-receiving surface, the number of sensors corresponding to the number of scanning lines (525 in the NTSC system) is lined up in the vertical direction, and the number of sensors corresponding to the number of pixels per line is lined up in the horizontal direction. I'm here. The output of this solid-state image sensor 4 is input to an A/I) converter 5,
It becomes a digital video signal. Here, this digital video signal has a sampling frequency of 4f, for example. (However, 3.579545MHz), the number of quantization bits is 8
It is a bit signal. The output of the A/D converter 5 is given to an encoder circuit 6, and processes such as Y color difference conversion and dichromatic difference subcarrier modulation are performed by digital processing. The output of this encoder circuit 6 is given to a D/A converter 7 and a frame (or field) memory 8.

The output of the D/A converter 7 is an analog video signal that complies with standards such as the NTSC system, and is supplied to the luminance signal recording circuit 16 and color signal recording circuit 15 of the VTR section, and is also transmitted via the changeover switch 10. It is also provided to the viewfinder 12 to display the moving image being captured. The changeover switch 1o is connected in the direction shown in the figure (picture side) when the VTR section is stopped or in the recording state, and in the opposite direction (PB side) when the VTR section is in the playback state. In the latter case, a reproduced video signal from the VTR section is supplied from the input terminal 11 to the viewfinder 12.

Also connected to the frame (or field) memory 8 is a determination circuit 37 for determining the length of a logic signal issued by a single-shot operation switch 9 mounted on the exterior of the device.

This operation switch 9 is a push button switch for starting/stopping recording that is normally provided in a VTR.

The determination circuit 37 measures the time during which the operation switch 9 is pressed, and if, for example, this measured time is longer than a preset reference time, it determines that the operation is for starting normal recording or stopping recording, and controls the operation. When the signal S1 is not output and the determination time is shorter than the reference time, it is determined that the operation is for recording a still image, and the control signal S is output. The memory 8 is operated by this control signal S, and the output of the encoder circuit 6 for the first frame (or one field) after the operation switch 9 is pressed is written into the memory 8 as still image information. Reading from this memory 8 is -
As an example, 2 equal to the sampling frequency of the audio signal, which will be described later.
This is done at a sampling frequency of f=+.

Note that when importing still image data into the memory 8 using the above method, there is no problem if the still image data is for one field, but if the still image data is for one frame, the interface The blurring of moving objects that accompanies race scanning becomes a problem. In order to prevent this, one frame is taken out as the sensor output of the solid-state image sensor by simultaneous reading of two lines adjacent in the vertical direction, and then reconstructed as an interlaced signal for two fields. All you have to do is find a way.

Furthermore, as shown in the figure, it is convenient to provide the output S□ of the determination circuit 37 to the viewfinder 12 and to display with letters or lamps that a still image is to be extracted into the memory 8 for recording.

The audio signal collected by the microphone 1 is amplified by the microphone amplifier 2 and then provided to the noise reduction circuit 13 of the VTR section.

The above has been a description of the camera section, but next, the VTR section will be explained.

The audio signal applied to the noise reduction circuit 13 is
After being given a non-linear high-frequency emphasis characteristic, the signal is given to the audio signal recording circuit 14 and the A/D converter 17. In the former, the audio signal is processed such as FM modulation and
．． The signal is converted into an FM audio signal having a carrier frequency around 5 MHz, and is applied to the adder 125A. In the latter case, for example, the sampling frequency is 15.734 KHz) and the number of quantization bits is 8 bits (actually, it is quantized to 10 bits and then compressed to 8 bits). supplied to

Among the analog signals output from the D/A converter 7, the luminance signal is supplied to the luminance signal recording circuit 16, where it undergoes processing such as FM modulation to become an FM luminance signal with a carrier frequency around 5 MHz, and the color signal is The signals are supplied to the color signal recording circuit 15, and subjected to processing such as frequency conversion to reduce the frequency, resulting in a low frequency converted color signal having a subcarrier frequency of 47.25 fH, respectively, and supplied to the adder 25A.

The pilot signal generation circuit 24 is connected to the luminance signal recording circuit 16.
6.5f+<, 7.5f per 1 field (1 recording track) due to the synchronization signal 5sync separated from the luminance signal and the tack pulse from the tank pulse generator 30.
+, 10.5f + 4.9.5fu, and adders 25A, 2.
Added to 5B. This pilot signal is a signal for tracking control during reproduction.

In this way, the adder 25A outputs the FM luminance signal,
A frequency multiplexed signal of the low frequency converted color signal, FM audio signal and pilot signal is output and supplied to the C contact of the changeover switch 26.

The switch 18 is switched according to the position of a bistable slide switch 19 which can be switched from the outside of the VTR. The slide switch 19 is used by the user to select whether to record a PCM audio signal or digitally record a still image on the overlap recording section of the track of the magnetic tape 36. Of course, in a VTR that is designed to overlap record only the latter, the A/D converter 17, the changeover switch 1
The 8° slide switch 19 is removed so that the output of the memory 8 is directly supplied to the data addition circuit 20.

Further, in this case, the changeover switch 18 may be used as an open/close switch, and this may be controlled to be turned on or off by the control signal S1 from the determination circuit 37.

In the data addition circuit 20, address information, a code (discriminating code for audio or still image, etc.), and a parity code for error correction during playback are added to the digital data from the changeover switch 18. access memory) is stored in the buffer memory 21.

When reading data from the buffer memory 21, the time axis is compressed so that it becomes an intermittent signal that can be recorded in the overpassive section. Then, the intermittent 8-bit parallel digital data from the buffer memory 21 is transferred to the parallel/serial conversion circuit 2.
2 becomes serial data, and at the same time, a CRC code is attached for error detection during reproduction, and then the PCM modulation circuit 23
This results in a transmission line code called a biphase mark. Further, the output of the PCM modulation circuit 23 is added to the pilot signal from the pilot signal generation circuit 24 by an adder 25B, and then is supplied to the d contact of the changeover switch 26.

The output of the changeover switch 26 is supplied to the recording head 35 (actually two) via the recording amplifier 27, and the magnetic tape 36 is
recorded in As is well known, the recording head 35 is a one-rotation drum mounted on a rotating drum (not shown).
The drum servo circuit 31 compares the phase of the output of the tack pulse generator 30 indicating the rotational phase of the drum motor 29 with the vertical synchronization signal of the synchronization signal 5sync from the luminance signal recording circuit 16. The rotation is controlled according to the Further, the output of the tack pulse generator 30 is waveform-shaped by the switch pulse generator 28, and the recording head 35 generates a switch pulse representing the moving image analog recording area and the overlap recording area of the recording track on the magnetic tape 36. . The changeover switch 26 is controlled by this switch pulse, so that the output of the adder 25A is placed in the video analog recording area of the recording track on the magnetic tape 36, and the output of the adder 25B is placed in the overlap recording area on the extension thereof. Each will be recorded.

Note that the magnetic tape 36 is run by the rotation of the capstan motor 32. In this case, the capstan motor 32
The capstan servo circuit 34 controls the capstan motor 32 based on the pulse of the frequency generator 33 which indicates the rotational speed of the magnetic tape 36.
Drive at a constant speed specified by the R standard.

Further, in the above example, the encoding method of the signal to be recorded in an overlap manner has been described in accordance with the current audio 8-bit PCM standard, but this is not a necessary condition. There is a possibility that a higher number of bits will appear in the future, and it may be possible to comply with that.

In any case, it is more convenient if the digital data processing circuits after the data addition circuit 20 can be used in common for audio digital data and still image data. By doing so, in FIG. 1, the part consisting of the memory 8 and the determination circuit 37, and the part consisting of the A/D converter 17 are separated from the main body, and the changeover switch 18 and slide switch 19 are separated from the main body. It is possible to realize a system in which one of the separated parts is attached according to the purpose, contributing to the miniaturization of the main body.

FIG. 2 is a plan view of the vicinity of the rotary head drum 38 on which the recording heads 35A and 35B in FIG. 1 are mounted. Arrow X in the figure indicates the rotation direction of the rotary head drum 38, and arrow Y indicates the running direction of the magnetic tape 36. As described above, the recording head 35 consists of two heads 35A and 35B, which are mounted on the rotary head drum 38 at a distance of 180 degrees from each other. The magnetic tape 36 is positioned by guide rollers 39A and 39B so that it is wrapped around the rotary head drum 38 by 210 degrees (actually 220 degrees to 230' including a margin). Therefore, the recording pattern on the magnetic tape 36 becomes as shown in FIG.

In other words, the approximately 180° wrapping period of each recording trunk serves as a video analog recording area for continuous video signals (FM
(including audio signals and pilot signals) remains approximately 30'
One cut of a digital still image signal or a digital audio signal (including a pilot signal) is recorded in each overlap recording area. In the above 18° period, one field per track, A 1 + in the figure.
A 21 B l! B2. The moving image signals are recorded in the order of... On the other hand, if you want to record one frame worth of still images in the overlap recording area,
It requires a considerable number of recording tracks. Current 8-bit PCM
According to the standard, the amount of data is 8400 bits/track. One frame is 4f. The sampling frequency is 3.8 Mb with 8-bit quantization (in case of composite quantization), so it takes about 450 Mb to record one frame of still image data.
track, that is, a recording time of about 7.5 seconds is required.

Therefore, when the contents of the A and A2 fields are recorded as one frame, the data is continuously recorded over a large number of recording tracks as shown in FIG. If recording is started immediately after one frame has been stored in the frame memory 8 of FIG. 1, recording will start from the extension of the B2 field, as shown in FIG.

[Effects of the Invention] As explained above, according to the present invention, the operating means for starting video recording can also be used as the operating means for starting still image recording, and the operating means for starting recording of a still image can also be used. It becomes possible to record moving images and still images while preventing the increase in size, making it possible to miniaturize the operation and improve usability during recording.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording/reproducing apparatus according to the present invention, FIG. 2 is a plan view showing the vicinity of the rotating head drum in FIG. 1, and FIG. 3 is a track on the magnetic tape in FIG. 1. It is a figure showing a pattern. 4... Solid-state image sensor, 6... Encoder, 8... Memory, 9... Operation switch, 15... Color signal recording circuit, 16... ...Brightness signal recording circuit, 18...Selector switch, 20.
...Data addition circuit, 23...PCM modulation circuit, 2
5A, 25B...adder, 26...changeover switch,
35... Recording head, 36... Magnetic tape, 37... Judgment circuit. Cicada figure 2%3 figure

Claims (1)

[Claims] 1. Each recording track on the magnetic tape has a first area and a second area.
At least a moving image signal can be recorded in the first area, a still image signal can be digitally recorded in the second area, and recording of the moving image signal can be started or started by operating an operating member. In a magnetic recording/playback device that stops recording, a first means for determining the length of an operation period of the operating member; and a second area of the recording track based on a determination output of the first means. and a second means for digitally recording a still image signal for one frame, and the first means functions as an operation member for recording the still image signal depending on the length of the operation period. A magnetic recording/playback device characterized by: