JPH01169774A - Disk type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To minimize the cutoff part of an inputted sound signal by providing a silent abbreviation means and skipping a silent part inside the sound signal to record. CONSTITUTION:A sound signal is inputted from an input terminal 15 through an A/D converter 6 to a RAM 7 and inputted through a silent detecting part 8 to a silent period memory 9. The RAM 7 compresses and records a sound with a semiconductor, which can store a sound signal equivalent to (m)sec, by the indication of a switch 16, and outputs data at high speed. On the other hand, the detecting part 8 is formed with a voltage comparator and a monostable multivibrator, and makes the memory 9 store the address of silent start and end memories. Then, the RAM 7 is started a sound fetching with a switch 1, when it is more than (n) seconds, an exceeding and the silent period are detected with a recording exceeding detecting circuit 20. Here, (m) and (n) are set values and the (m) is a larger value than the (n). During the above- mentioned silent period, it is shorted-circuit and outputted from the RAM 7, and minimizes a cutoff due to exceeding.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a disk-shaped magnetic recording and reproducing device that is effective for use in recording audio such as video floppy disks.

BACKGROUND OF THE INVENTION In addition to recording video signals on video floppies with a diameter of less than 2 inches, there is active development and commercialization of devices that record and reproduce audio signals.

Recording of audio will be explained with reference to FIG. 34 is an input terminal for the audio signal, and 35 is a low-pass filter for sampling the audio signal, for example, the cutoff frequency is 5k)h. This audio signal is transferred to the AD converter 3.
6, it is converted into an 8-vinyl digital signal and is stored in a random access memory IJ (hereinafter referred to as RAM) 37. The audio stored sequentially in this way can be transferred to the RAM 37 at twice the speed.
The audio input from the input terminal 34 is time-compressed by two times by reading the audio from the input terminal 34, converting it into analog data using the DA converter 38, and passing it through the low-pass filter 39. This signal is subjected to FM modulation 640 for FML, recording layer jW1 circuit 4
By applying the recording current to the head 42 as a recording current, time-compressed audio can be recorded on a floppy disk (not shown). 31 is a switch for instructing the start of recording, 32 is a timing control circuit for generating timing signals to each circuit, and 33 is a RAM control circuit for controlling the random access memory. Here, if the above-mentioned K is set to 840, the voice with the highest frequency of 6kHz will be compressed to 3.2 degrees of voice, and 1
Approximately 16.7 m5 x 640 = 10.7 seconds can be recorded in one rotation time of the truck, which is approximately 15.7 mfi (1 TV field). In other words, by compressing it 640 times,
Approximately 10 seconds of audio (maximum frequency 6 songs) can be recorded per track.

Problems to be Solved by the Invention However, in the conventional configuration described above, the recording time per trunk is approximately 10 seconds as described above, and audio longer than this is truncated. This is a major drawback in audio recording, and it is desirable to absorb this slight excess.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention aims to provide a disk-shaped magnetic recording/reproducing device that can record audio that is longer than the recording time per track without truncating as much as possible.

Means for Solving the Problems The disk type magnetic recording/reproducing device of the present invention has one track of n8).
A multi-track disk-type magnetic recording and reproducing device that compresses and records audio signals for minutes,
It has a configuration including a semiconductor memory capable of storing audio signals for seconds, a detection means for detecting that the audio signal exceeds n seconds, and a silence reduction means for skipping the silent portion of the audio signal.

Operation The present invention uses the above-described configuration to detect, by means of the production means, that the audio signal for m seconds to be recorded exceeds n seconds;
By skipping the silent portion of the m seconds worth of audio signals to be recorded using the silence reduction means, it becomes possible to record m seconds worth of audio signals.

Example An embodiment of the present invention will be described below based on the drawings.

In Fig. 1, 15 is an audio signal input terminal, 6 is an AD
It is a converter. 7 is a random access memory (RAM) that stores the digitized audio signal controlled by RAM control times @4;
It has a capacity for seconds. Reference numeral 1 denotes a switch for starting to capture audio into the random access memory 7. Reference numeral 2 denotes an audio confirmation switch, which is a switch for reproducing the audio in the RAM 7 at the input speed. In this case, the reading timing of the RAM 7 is the same speed as when recording, and the DA converter 10 converts the audio into analog. 3 is a timing control circuit, RAM control circuit 4° recording amplifier circuit 13
Outputs the timing signal to

17 is a low pass filter (LPF) with a cutoff frequency of 6 crystals. 18 is an audio output circuit, and 19 is a speaker. The switch 16 is a switch for compressing and recording the audio in the RAM 7, and according to the instruction of this switch 16, data is output from the RAM 7 at high speed, and the data is output from the DA.
The converter 10 converts the signal into an analog signal. 11 is a low-pass filter whose cutoff frequency is approximately 3.2, and the output of this low-pass filter 11 has a maximum frequency of 3.
, resulting in two audio signals. 12 is an FM modulation circuit, 13 is a recording amplification circuit, and 14 is a recording head.

Reference numeral 8 denotes a silence detection section, and 9 denotes a silence period memory that stores memory addresses for the start and end of silence.

An example of silence detection is shown in FIGS. 2 and 3. 21 is an audio input terminal, and 22 is a voltage comparator. As shown in FIG. 3(a), when the audio signals are compared at the comparison level vTH, a pulse (b) is generated. 23 is a retriggerable monostable multivibrator with a pulse width T1, and when the signal (B) is input, the pulse shown in (C) is obtained, and the H level period is audible.

The L level period indicates silence.

Reference numeral 2o in FIG. 1 is a recording excess detection circuit, which detects and displays poems in which there is additional voice after recording for n seconds.

With the above configuration, when the voice input exceeds n seconds, the excess is produced and displayed. On the other hand, when a silent period is also detected and there is a silent interval, this part is short-circuited and output from the RAM 7, and after each process, it is recorded on the floppy disk, thereby minimizing truncation due to excess. can.

R When the excess is R seconds, truncation can be eliminated by setting the compression ratio to 640X(-+1).

Effects of the Invention As described above, the present invention can minimize the truncated portion of the audio signal that is input beyond the predetermined time when recording the audio signal on a 70-speed disc with a predetermined recording time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a disc-shaped magnetic recording and reproducing device according to an embodiment of the present invention, FIG. 2 is a block diagram showing details of the silence detecting section of the same device, and FIG. 3 is an operation of the silence detecting section. FIG. 4 is a block diagram showing a conventional disc type magnetic recording/reproducing device. 7... Random access memory, 8... Silence detection section, 9... Silence period memory, 20...-
... Recording excess detection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3

Claims (1)

[Claims] A multi-track disk-type magnetic recording and reproducing device that time-base-compresses and records n seconds worth of audio signals on one track, and a semiconductor memory capable of storing m seconds worth of audio signals greater than the n seconds; A detecting means for detecting that the audio signal exceeds n seconds, and a silence shortening means for skipping the silent part of the audio signal, and when the time exceeds the length, the shortened audio signal is compressed in time axis and recorded. A disc-shaped magnetic recording and reproducing device characterized by: