JPH0327686A - Still video equipment - Google Patents

Abstract

PURPOSE:To simplify the circuit constitution and to reduce the cost by constituting a storage means writing an audio signal, and a storage means writing a video signal with a common storage means. CONSTITUTION:A video signal inputted to an A/D converter 51 via an audio/ video changeover switch 49 is converted into a digital video data and one pattern is written sequentially in a RAM 53. The video data by one pattern to be written is read sequentially and converted into an analog video signal at a D/A converter 55. On the other hand, the audio signal inputted to the converter 51 is converted into a digital audio data and written in the RAM 53 for a prescribed time. The audio data written for a prescribed time is read sequentially and converted into an analog audio signal at the converter 55. Thus, since the converters 51, 55 and the RAM 53 are used in common for the audio signal circuit and the video signal circuit in this way, the circuit constitution is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a still video device capable of recording and reproducing audio and video. "Prior Art and its Problems" In recent years, various still video cameras and still video playback devices have been developed that can record a subject image as an electrical video signal and also record audio on a recording medium (magnetic disk). Hereinafter, in this specification, electronic still cameras, still video playback devices, and the like will be collectively referred to as still video devices.

Magnetic disks usually have approximately 3. Rotates at 60Orpm,
One field of image signals is recorded on one track.
On the other hand, although audio signals are also recorded on the tracks, the time required for recording/reading per track is extremely short, about i/60 seconds. Therefore, when recording audio time, the time axis is compressed, and when playing back, the time axis is expanded, thereby making it possible to record audio for 5 to 20 seconds.

In one example of this compression/expansion means, an audio signal is once converted into a digital signal at the time of recording, and then stored in a storage means (RAM).
will be written to. The audio signal for a predetermined period of time written in the RAM is read out in about 1/60 seconds, that is, the audio signal is compressed in the time axis, converted to an analog signal, and recorded on one track of the magnetic disk. During playback, one track of the magnetic disk is read, converted to a digital signal, and sequentially written to the RAM. Then, the audio signal for one track written in the RAM is read out slowly, ie, time-axis expanded to the original recording time, and converted into an analog signal.

The above processing allows approximately 5 to 20 seconds of audio recording. In addition, during video playback, in order to obtain special effects such as multi-screen, or to obtain stable still images without flickering or fluctuation, the video signal for one screen read from the magnetic disk is temporarily stored in a storage device (RAM). ) and read it from this RAM to convert it into a video signal has been developed. The configuration of a still video apparatus equipped with the above-mentioned audio recording/reproducing function and video signal storage means is as shown in FIG. 2, for example. The video signal input from the video input terminal 11 is sent to the video signal processing circuit l3, the audio/video changeover switch 15, and the FM
The signal is recorded on a predetermined track of the magnetic disk 25 as a multiplexed signal via the modulation circuit 17, the recording amble 19, and the magnetic head 23. The video signal recorded on the magnetic disk 25 is read by the magnetic head 23 during reproduction, and is read by the recording/reproduction changeover switch 2.
1 to the reproduction amplifier 33, where it is amplified. Next, the signal is demodulated by the FM demodulation circuit 34, processed into a video signal consisting of a predetermined luminance signal and color difference signal by the video signal processing circuit 37, and outputted to a low-pass filter (LPF) 47a and a changeover switch 39. High frequency components are removed from the video signal output to the low-pass filter 47a, and the video signal is converted into predetermined digital video data by the A/D conversion circuit 51a. Then, image data for one screen is sequentially written into the image RAM 53a via the data path. The video data for one screen written in the video RAM 53a is sequentially read out from there via the data path and sent to the D/D.
The A converter 55a converts it into an analog video signal. The signal is then output to the video signal processing circuit 4l via the low-pass filter 57a and the changeover switch 39, where it is converted into a video signal and output to the video signal output terminal 43. If a monitor television is connected to this video output terminal 43, still images can be viewed. In addition, the changeover switch 3 can be directly connected to the video signal processing circuit 37.
The video signal output to 9 is also converted into a video signal by the video signal processing circuit 41 in the same manner as described above, and is output to the video signal output terminal 43. Note that the video signal processing circuit 37 and the A/D converter 51
a. The operations of the video RAM 53a and the D/A converter 55a are controlled by the digital signal processing circuit 61a, and the switching operations of the changeover switches 15, 2l, and 39 are as follows:
It is controlled by a system controller 63. In addition to the above-mentioned control, the system controller 63 also performs overall operation control of the digital signal processing circuit 61a, the servo circuit 27, and the like, and of the entire still video apparatus.

On the other hand, the audio is converted into an electrical audio signal by the microphone 69, and outputted to the A/D converter 5lb via the bass filter 71, the audio signal processing circuit 72, the low-pass filter 75, and the playback/recording switch 49. The analog audio signal input to the A/D converter 5lb is converted into predetermined digital audio data, and sequentially written for a predetermined time into the audio RAM 53b via the data path. The audio data for a predetermined period of time written in the audio RAM 53b is read out at high speed via the data path.
It is converted into an analog audio signal by the D/A converter 55b. The read speed is the speed at which audio data for a predetermined time can be written on one track of the magnetic disk 25, that is, about 1
/60 seconds. In this way, the audio signal during recording is A
The time axis is compressed by the /D converter 5lb, audio RAM 53b, and D/A converter 55b. The compressed audio signal output from the D/A converter 55b is outputted to the FM modulation circuit l7 via the changeover switch 57, the low-pass filter 59, the compressed audio signal processing circuit 77, and the audio/video changeover switch 15, where it is FM modulated. Then, it is output to the magnetic head 23 via the recording amplifier 19, and the magnetic head 23 causes the magnetic disk 25 to
is recorded on one predetermined track.

During audio reproduction, a compressed audio signal recorded on one track of the magnetic disk 25 is read by the magnetic head 23,
Playback amplifier 33 via recording/playback switch 21
The signal is output to the FM demodulation box 34, where it is amplified and demodulated by the FM demodulation box 34.

The demodulated compressed audio signal passes through the low-pass filter 47b, and is output to the A/D converter 5lb via the audio recording/playback switch 49. The compressed audio signal input to the A/D converter 5lb is converted into digital audio data, and is sequentially sent to the audio RAM 53b via the data path.
One track is written. The audio data for one track written in the audio RAM 53b is slowly read out and converted into an analog audio signal by the D/A converter 55b. In other words, A/D converter 5lb, audio RAM 5
3b and a D/A converter 55b, the time axis is expanded and the length is returned to the original recording length. The signal is then outputted to the low-pass filter 79 via the changeover switch 57, where the Takagi component is removed, subjected to predetermined processing in the audio signal processing circuit 81, amplified by the amplifier 83, and converted into audible audio by the speaker 85. Ru.

As mentioned above, the above-mentioned still video device equipped with the conventional audio recording/playback function and the video-only storage means has the audio-only storage means (
Since it is equipped with two storage means, an audio RAM 53b) and a video dedicated storage means (video RAM 53a), when peripheral circuits are added, the structure becomes complicated and the cost increases. Furthermore, since the audio-only storage means is not used during video signal recording/reproduction, and the video-only storage means is not used during audio signal recording/reproduction, the storage means is not effectively utilized.

``Object of the Invention'' The present invention was made based on the above-mentioned conventional problem awareness, and an object of the present invention is to provide a still video device with a simple circuit configuration. "Summary of the Invention" The present invention achieves the above object by reading audio signals for a predetermined time recorded on a recording medium in a time-axis compressed manner and writing them into a storage means, and storing the written audio signals. Audio playback means that reads at a low speed and extends the time axis to the original predetermined time; and video playback means that reads the video signal recorded on the recording medium and writes it to the storage means, and reads the video signal written to the storage means. The still video apparatus is characterized in that the storage means for writing the audio signal and the storage means for writing the video signal are configured as a common storage means.

According to the above Makiaru, since the audio storage means and the video storage means are shared by a common storage means, it is possible to reduce the number of storage means and simplify the circuit configuration.

The present invention can also be applied to a still video device, such as an electronic still camera, equipped with an audio signal and video signal recording device. "Embodiments of the Invention" The present invention will be described below based on illustrated embodiments.

FIG. 1 is a block diagram showing the configuration of an embodiment of the magnetic recording/reproducing apparatus of the present invention. Note that members having the same functions as those of the conventional example shown in FIG. 2 are given the same reference numerals.

First, the configuration and operation related to video signal recording will be explained. During video recording, a video signal from an imaging section (not shown) or from another still video device is input via the video input terminal 11. This video signal is
The video signal processing circuit 13 processes the video signal into a video signal consisting of a luminance signal and a color difference signal, and outputs it to the FM modulation circuit 17 via the audio/video changeover switch l5. The video signal is modulated into an FM multiplex signal by the FM modulation circuit l7, amplified by the recording amplifier 19, and outputted to the magnetic head 23 via the recording/reproduction changeover switch 2l. recorded on the track. Note that in the case of field recording, data is recorded on one track, and in the case of frame recording, data is recorded on two adjacent tracks in order. The magnetic disk 25 is rotationally driven by a servo motor 29 controlled by a servo circuit 27. The servo circuit 27 controls the rotation of the servo motor 29 according to pulse signals from the PG coil 3l, and also controls the rotation of the magnetic head 23.
It also performs tracking control. During video signal reproduction, the video signal recorded on the magnetic disk 25 is read track by track by the magnetic head 23, outputted via the recording/playback switch 21 to the playback amplifier 33, where it is amplified and FM demodulated. circuit 34
is demodulated by the video signal processing circuit 37, processed into predetermined luminance signals and color difference signals, and then sent to the audio/video changeover switch 4.
5 and the video selector switch 39. audio/
The video signal output to the video changeover switch 45 has high frequency components removed by a low-pass filter 47, and is output to the A/D converter 51 via the audio/video changeover switch 49. The video signal input to the A/D converter 51 is converted into predetermined digital video data, and data for one screen is sequentially written into the RAM 53 via the data path. RAM
The video data for one screen written in the D/A converter 53 is sequentially read out via the data path and converted into an analog video signal by the D/A converter 55. Then, it is output to the low-pass filter 59 via the audio/video changeover switch 57,
Here, high frequency components are removed and the signal is output to the video signal processing circuit 41 via the audio/video changeover switch 39.

The video signal input to the video signal processing circuit 41 is converted into a video signal and output as a video signal from the video output terminal 43. If a monitor television is connected to this video output terminal 43, still images can be viewed. Note that the video signal directly output from the video signal processing circuit 37 to the changeover switch 39 is also converted into a video signal by the video signal processing circuit 41 in the same manner as described above, and is output as a video signal from the video signal output terminal 43. The above is the configuration related to recording and playing back video signals. In the above configuration, A/D converter 51, RAM 53 and D
The operation of the /A converter 55 is controlled by the digital signal processing circuit 61, and the video signal processing circuit 13 and the servo circuit 2
7, video signal processing circuit 37, digital signal processing circuit 6
l operation and changeover switches 15, 21, 39, 45
, 57 are collectively controlled by a system controller 63. The system controller 63 is usually composed of a microcomputer and performs the above control according to a program stored in an internal memory.

The system controller 63 also includes a playback switch,
An operating section 65 equipped with operating switches such as a recording switch and an audio/video changeover switch is input, and the system controller 63 performs various controls in response to operations on the operating section 65Φ.

Next, the configuration and operation related to audio will be explained.

The voice is picked up by a microphone 69 and converted into an electrical voice signal. This audio signal is amplified by the Brian 71, subjected to predetermined processing by the audio signal processing circuit 73, high-frequency components are removed by the low-pass filter 75, and sent to the A/D converter 5 via the playback/audio input switch 49.
1 is output. The audio signal input to the A/D converter 51 is converted into predetermined digital audio data and sent to the RA via a data path.
The information is sequentially written into M53 for a predetermined period of time. The audio data for a predetermined period of time written in the RAM 53 is sequentially read out at high speed via the data path, and converted into an analog audio signal by the D/A converter 55. The above reading speed is the speed at which a predetermined time worth of audio signals can be written on one track of the magnetic disk 25, that is, about 1/60 seconds. In this way, the audio signal during recording is sent to the A/D converter 51. The time axis is compressed by the RAM 53 and the D/A converter 55. The compressed audio signal output from the D/A converter 55 is output to the low-pass filter 59 via the changeover switch 57, where high frequency components are removed, and predetermined processing is performed in the compressed audio signal processing circuit 77. Ru. Then, it is outputted to the FM modulation circuit l7 via the audio/video changeover switch 15, where it is FM modulated, amplified by the recording amplifier 19, and outputted to the magnetic head 23 via the recording/playback changeover switch 21, and this magnetic The head 23 drives the magnetic disk 2
5 is recorded on one predetermined track. During audio playback, the compressed audio signal recorded on the magnetic disk 25 is read by the magnetic head 23, and output to the playback amplifier 33 via the recording/playback switch 2l.
Here, the signal is amplified and demodulated by the FM demodulation circuit 34. The demodulated audio signal is output to the low-pass filter 47 via the audio/video switching circuit 45, where the Takagi frequency component is removed, and then the playback/audio input switching switch 49
The signal is output to the A/D converter 51 via the A/D converter 51. The compressed audio signal input to the A/D converter 51 is converted into predetermined digital audio data, and one track worth of data is sequentially written into the RAM 53 via the data path. The audio data for the tracks is slowly read out via the data path and converted into an analog audio signal by the D/A converter 55. This readout speed is the speed at which the compressed audio signal reaches its original recorded length. In this way, the audio signal is sent to the A/D converter 51, the RAM
53 and a D/A converter 55, the time axis is expanded. The audio signal restored to its original length is output to the low-pass filter 79 via the audio/video changeover switch 57, where the Takagi component is removed, and the audio signal is converted into a predetermined audio signal that can be reproduced by the audio signal processing circuit 8l. is processed and amplified by amplifier 83. Then, the speaker 85 converts it into audible audio. Note that the A/D converter 51, RAM 53
The time axis compression and time axis expansion operations by the D/A converter 55 are controlled by the digital signal processing circuit 61. Also, the operations of the audio signal processing circuit 73, the compressed audio signal processing circuit 77, and the audio processing circuit 81, and the switching operations of the playback/audio input changeover switch 49, changeover switch 57, audio/video changeover switch l5, and audio/video changeover circuit 45 are also described. is controlled by the system controller 63. Further, the system controller 63 instructs whether the digital signal processing circuit 61 performs the recording/reproducing operation of an audio signal or the recording/reproducing operation of a video signal. As described above, according to the present still video device, the A/D converter 51, RAM 53, D/A converter 55, and digital signal processing circuit 6l are shared by the audio signal circuit and the video signal circuit. Compared to , there are fewer circuit elements and the circuit configuration is simpler.

In this embodiment, a configuration is shown in which one track's worth of audio signals and one screen's worth of video signals are stored in the RAM 53 and recorded/played. However, multiple tracks of audio signals, multiple screens' worth of video signals, or audio signals It is also possible to create a structure in which both the video signal and the video signal can be stored in memory. "Effects of the Invention" As is clear from the above description, according to the still video apparatus of the present invention, the storage means for video signal processing and the storage means for audio signal processing are commonly configured, so that the storage means can be effectively used. In addition, since the number of storage means is reduced, the circuit configuration becomes simpler, and the still video apparatus can be made more compact and the cost can be reduced.

FM demodulation circuit, 37... Video signal processing circuit, 39...
- Audio/video changeover switch, 41... Video signal processing circuit, 43... Video output terminal, 49... Playback/audio input changeover switch, 51... A/D converter, 53.
・RAM, 55 ・D/A converter, 57 ・Record/playback switch, 61 ・Digital signal processing circuit, 63 ・System controller

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an embodiment of the still video apparatus of the present invention, and FIG. 2 is a block diagram showing the circuit configuration of a conventional still video apparatus.

Claims (2)

[Claims] (1) Read the audio signal for a predetermined time recorded on a recording medium in a time-axis compressed manner and write it to a storage means, read the audio signal written to the storage means at a low speed and expand the time-axis to the original predetermined time. A still video apparatus comprising: an audio reproducing means for reading a video signal recorded on the recording medium, writing it in a storage means, and reading the video signal written in the storage means, the still video apparatus comprising: A still video apparatus characterized in that a storage means for writing an audio signal and a storage means for writing the video signal are constituted by a common storage means. (2) audio recording means for writing audio signals for a predetermined time into a storage means, reading out the audio signals for a predetermined time written in the storage means at high speed, compressing the time axis, and recording them on a recording medium;
The audio signal for a predetermined time recorded on the recording medium in a time-axis compressed manner is read and written to the storage means, and the audio signal written to the storage means is read out at a low speed and expanded in time to the original predetermined time. an audio reproduction means; a video recording means for recording a video signal on the recording medium; a video reproduction means for reading the video signal recorded on the recording medium, writing it into the storage means, and reading out the video signal written in the storage means. 1. A still video apparatus comprising: a storage means for writing the audio signal and a storage means for writing the video signal; and a storage means for writing the audio signal and a storage means for writing the video signal are configured as a common storage means.