JPS63234485A - Sound recorder - Google Patents

Abstract

PURPOSE:To correct the contents of a sound recorded on a recording medium easily in a short time by recognizing a sound signal recorded on the magnetic medium by hearing it as the sound from a sound output device before it is recorded on the magnetic medium. CONSTITUTION:The sound signal 107a stored in a memory 108 by synchronizing with a first clock signal 111a is read by a clock signal 112a having a higher frequency than the first clock signal 111a, thereby, an ordinary sound can be reproduced and the sound signal 107a stored in the RAM 108 can be recognized. Thereby, when the contents of the initially inputted sound cannot be satisfied or when it is desired to change the contents, a new sound signal in which the contents are corrected may be easily rewritten in the RAM 108.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an audio recording device, and the present invention relates to an audio recording device, in which the content of the audio recorded in advance is recorded when an audio signal is recorded on a magnetic medium such as a floppy disk on which an image signal is recorded. It is designed to enable confirmation of the

<Prior art> Devices such as electronic still cameras that record image signals of still images on magnetic disks are already known, and have a diameter of approximately 47 m.
, one using a floppy disk with a thickness of about 40 μm has been standardized and put into practical use. The floppy disk is rotated at 3600 rpm, and 50 frames of still images are recorded on 50 tracks for field recording, and 25 frames of still images are recorded for frame recording. Track width is 60μm,
) The rack pitch is 100μm, with 40μm between tracks.
A μm guard band is provided. The reproduced image is displayed on a monitor such as a television set or printed as a hard copy by a printer.

To record an audio signal on such a floppy disk, time axis compression is performed, and when playing back, time axis expansion is performed. In other words, a floppy disk rotates once every 1/60 seconds, so it can only record 1/60 seconds per track, but by compressing the time axis to, for example, 1/640, it is possible to record approximately 10 seconds of audio signals. can. The audio signals include signals in various audio areas, such as explanations of recorded still images, background music for viewing reproduced images, and background sounds when images are taken with an electronic still camera.

FIG. 2 shows the block configuration of a typical audio signal recording system, and FIG. 3 shows the block configuration of its reproduction system.

In FIG. 2, an audio signal 3 applied from a microphone 1 to an input terminal 2 is passed through a low-pass filter (LPF) 4 and a noise reduction filter 2 (NR) 5, and then input to a time axis compression device 6. Ru. Time axis compression device 6
is equipped with an A/D converter 7, a RAM (random access memory IJ) 8, a D/A converter 9, an address counter 10, a write clock generator @s11, and a read clock generator 12.

A recording start switch 13 and a PG detection device 14 are connected to the address counter 10. If the time compression rate is M times, the frequency of the read clock signal 12a is as follows.
It is set to M times the frequency f6 of the write clock signal 11a, that is, M.-. Noise reduction circuit 5
The audio signal 5a from the A/D converter 7 is converted into a digital audio signal 7a at a sampling frequency of f. This digital audio signal 7a is transmitted to the recording start switch 1
3 is turned on, the address counter 10 advances the address at the f9 clock frequency, and then the RA
Please write it on M8. 10a is an address signal. R.A.
When the digital audio signal 7a is completely stored in the predetermined area of M8, the address counter 10 advances the address at a clock frequency of Mf in synchronization with the PG signal 14a from the PG detection device 14 and reads out the contents of the RAM 8. The read digital audio signal 8a is converted into M-fs by D/A conversion.
It is converted into an analog audio signal 9a at a clock frequency of .

The analog audio signal 9a obtained as described above is the audio signal 3 applied to the input terminal 2 whose time axis is compressed to 1/M.

After the time-compressed analog audio signal 9a is high-frequency emphasized by a pre-emphasis circuit 15, the frequency modulator (FM
MOD) 16 to undergo modulation processing, and then to the recording amplifier 17.
The information is then recorded on an appropriate natrac of the floppy disk 19 through the magnetic head 18. 20 is a motor that rotates the floppy disk 19.

The time compression rate is determined by the frequency band that can be recorded on the floppy disk 19 and the upper limit frequency required when recording audio signals. In an electronic still camera or the like, a 6 MHz carrier can be FM-modulated and recorded on a floppy disk rotating at 3600 rpm with an audio signal having a band of 3.2 MHz after pressure w3. Therefore, if the upper limit frequency of the audio signal is f, KHz, then M=3
200/f. Also, the time T of the audio signal that can be recorded is T=M・1/60=3200/60 f,
becomes. In Table 1, f, = 2.5 KHz, 5
The specifications for each side of KHz and 10 KHz are shown.

Table 1 For playback, as shown in Figure 3, press playback switch 3.
2 is turned on, the signal 21a from the magnetic head 21 is input to the reproducing amplifier 22, and after amplification, the signal 21a is input to the demodulator (FM D
The frequency modulation is demodulated by the EMOD) 23, the high frequency is suppressed by the de-emphasis circuit 24, and the time axis expansion device 25
be entered into. The time axis expansion device 25 is an A/D converter 26
, RAM 27, D/A converter 28, address counter 2
9, a write clock generator 30, and a read clock generator 31. A regeneration switch 32 and a PG detection device 33 are connected to the address counter 29. The frequency of the write clock signal 30a is Mf, which is the same as that of the read clock signal 12a in the time axis compression device i16 of the recording system shown in FIG. Further, the frequency of the read clock signal 31a is the same f as that of the write clock signal 11a in the time axis compression device 6. The time-compressed analog audio signal 24a obtained from the de-emphasis circuit 24 is converted into a digital audio signal 26a at a sampling frequency of Mf by an A/D converter 26. This digital audio signal 26a is transmitted to the PG detection device 33.
The address counter 29 is synchronized with the PG signal 33a from
is stored in the RAM 27 by advancing the address at a clock frequency of M-f. 29a is an address signal. Digital audio signal 2 is stored in a predetermined area of RAM 27.
When 6a has been stored, the address counter 29 advances the address at a clock frequency of f and reads out the contents of the RAM 27.

The read digital audio signal 27a is sent to the D/A converter 28.
The analog audio signal 28 with a clock frequency of f
It is converted to a. The analog audio signal 28a obtained in the above manner is a signal in the audio band whose time axis has been restored to its original state.

This audio signal 28a is passed through a low pass filter (LPF) 34.
, noise reduction circuit (NR) 35 and amplifier 36
is applied to the speaker 37 and output as sound.

<Problems to be Solved by the Invention> In the above-described conventional technology, when an audio signal is recorded on the floppy disk 19, it is recorded on the floppy disk 19 immediately after the audio signal is input to the RAM 8. Furthermore, since the recording time of the audio signal recorded on the floppy disk 19 is limited to about 5 to 20 seconds, it is not always possible to record satisfactory content in one go within this time. Therefore, when an audio signal is recorded on the floppy disk 19, it is played back each time and the content is converted to Mii, and if the content needs to be modified, it must be erased and recorded again, which is cumbersome and time-consuming. was.

The present invention has been made for the purpose of solving the above-mentioned problems, and it is an object of the present invention to provide an audio recording device in which the content of the audio signal to be recorded can be confirmed in advance before the audio signal is recorded on the floppy disk 19. It is.

Means for Solving the Problems> To solve the above problems, the present invention provides: (a) an A/D converter that converts an input audio signal, which is an analog signal, into a digital audio signal, and fb) the digital audio signal. tel A D/A converter that converts the digital audio signal read from the memory into an analog audio signal, fdl An address counter that specifies the address of the memory to be written/read, (,1 a magnetic recording device that records the analog audio signal on a rotating magnetic recording medium; (f) an audio output device that outputs the analog audio signal as audio; (h) when writing the digital audio signal into the memory, writing the digital audio signal into the memory in synchronization with a first clock signal; When outputting audio from the audio output device, a digital audio signal is read out from the memory in synchronization with the first clock signal.
When sending the /A-converted analog audio signal to the audio output device via the audio signal changeover switch and recording the analog audio signal on a magnetic recording device, first, the magnetic recording device whose power supply is stopped by a power supply stop signal. A power supply signal is output to the D/A to start power supply, and then a digital audio signal is read out from the memory in synchronization with a second clock signal having a higher frequency than the first clock signal.
a system controller that sends the converted analog audio signal to a magnetic recording device via the audio signal changeover switch; (i) setting conditions for selecting whether the input audio signal is output as audio or magnetically recorded in the system controller; The present invention is characterized by comprising an input device that performs the following operations.

Function> By reading out the audio signal stored in the memory in synchronization with the first clock signal with a lock signal that has a higher frequency than the first clock signal, normal audio can be reproduced, and the RAM
You can check the audio signals stored in the .

Practical example Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In this figure, from the microphone 101 to the input terminal 10
The audio signal 103 added to 2 is passed through a low-pass filter (L
PF) 104 and noise reduction times 1 @ (NR)
After being passed through 105, it is input to time axis conversion device 106. The time axis converter 106 is an A/D converter fill O7
, RAM (Random Access Memory) 108, D
/A-hen f! J1. Book 109, address counter 1101
A clock generator 111 for writing, a clock generator 112 for reading, and a clock changeover switch 113 are provided.

If the time compression rate is M times, the frequency of the clock signal 112a of the clock generator 112 is
M times the frequency f of the clock signal 111a, that is, M-
fs is set.

Audio equalization number 105 from the noise reduction circuit 105
a is converted to f by the A/D converter 107.

It is converted into a digital audio signal 107a at a sampling frequency of . This digital audio signal 107a is stored in RAM1.
Written in 08.

The D/A converter 109 includes a clock changeover switch 113.
through clock signal 111a or clock signal 112
Enter a. On the other hand, the digital audio signal 108a read from the RAM 108 is converted into an analog audio signal 109a by the D/A converter 109.

The audio signal changeover switch 114 distributes the analog audio signal 109a to the magnetic recording device 115 and the audio output device 116 by performing a switching operation. The magnetic recording device 115 includes a pre-emphasis circuit 117, a frequency modulator (FM MOD) 118, and a recording amplifier 1.
19.1ilfi head 120, floppy disk 1
21, a motor 122, and a PG detection device 123. On the other hand, the audio output device 116 includes an amplifier 124 and a speaker 125.

The system controller 126 includes a PG detection device 123
, a keyboard 127, a recording start switch 128, and an audio signal start switch 129 are connected. This system controller 126 has address counter 1
10, and sends an addressing signal 126a to
A read/write signal 126b is sent to the RAM 108. Then, the system controller 126
A power supply signal 130a is sent from 0 to a power supply switch 131 that turns on and off power supply to the magnetic recording device 115. Although not shown in the figure, the Ti source section 130 and the magnetic recording device 1
Power is supplied to the entire audio recording device including 15.

Next, the operation of the audio recording device having such a configuration will be explained. In recording time mode, the compression ratio M is 640.
double, f9 is 10 KHz.

It is assumed that the Mf is set to ``10 second mode'' of 6.4 MHz.

(il Write operation to RAM 108: First, the system controller 126 resets the specified address by the address counter 110 using the address designation signal 126a, and also resets the address specified by the address counter 110 using the read/write signal 126b.
Put AM108 into writing state. In this state, sound is emitted toward the microphone 101 and the recording start switch 128 is turned on. The audio signal 103 from the microphone 101 passes through the LPF 104 and the NR 105 to become an audio signal 105a, and this audio signal 105a is converted into a digital audio signal 107a by the A/D converter 107 at a sampling frequency of f. This digital audio signal 107a is written into the RAM 108 by the address counter 110 advancing the address at a negative clock frequency after the recording start switch 128 is turned on. Such writing is completed in about 10 seconds.

(iil Audio output operation: To output the audio after writing is completed by the operation of (it) described above, first, the system controller 12
6, the power supply signal 130a to the power supply switch 131
It is set to the itOFFi state and a power supply stop signal 41 is output 1 to stop the power supply to the magnetic recording device 115. Thereafter, a voice output command is input to the system controller 126 using the keyboard 127. Then, the system controller 126 switches the clock changeover switch 113 to the terminal 113.
Connect the audio signal selector switch 114 to the terminal 114 on the a side.
At the same time, the read/write signal 126b puts the RAM 108 into a read state. In this state, turn on the audio signal start switch 129.
The address counter 110 reads the contents of the RAM 108 by advancing the address at f, the Naro clock frequency. The read digital audio signal 108a is sent to the D/A converter 109.
Analog audio signal with f6 clock frequency 10
9a.

In this case, the time axis of the analog audio signal 109a is equal to the time axis of the audio signal 103, which is approximately 10 seconds. The analog audio signal 109a passes through the audio signal changeover switch 114, is amplified by the amplifier 124, and reaches the speaker 125.

Therefore, audio can be output from the speaker 125.

You can ask this voice and check its contents.

In this way, the audio signal recorded on the floppy disk 121 can be heard as audio from the speaker 125 before it is recorded on the 4P disk 121. Therefore, if you are not satisfied with the content of the audio that was initially input, or if you wish to change the content, you can easily do so by rewriting a new sound-signal with modified content to the RAM 108 as described above. .

011) Magnetic recording operation: After the writing is completed by the above-mentioned operation (il) and the content of the audio signal to be recorded on the floppy disk 121 has been checked by the above-mentioned operation (11), magnetic recording is performed. To perform magnetic 4A recording, first, the system controller 126 sends a power supply signal 130 to the power supply switch 131.
a is output, the power supply switch 131 is turned on, and power supply to the magnetic recording device 115 is started. Then keyboard 1
27 sends a magnetic recording command to the system controller 126.
Enter. Then, the system controller 126 turns the clock changeover switch 113 to the terminal 113b side and the audio signal changeover switch 114 to the terminal 114b side, and puts the RAM 108 into the read state by the read/write signal 126b. When the audio signal start switch 129 is turned on in this state, the address counter 10 advances the address at a clock frequency of Mf and reads out the contents of the RAM 108. The read digital audio signal 108a is converted into an analog audio signal 109a by the D/A converter 109 at a clock frequency of Mf.
is converted to In this case, the time axis of the analog audio signal 109a is obtained by strictly compressing the time axis of the audio signal 103.

The time-compressed analog audio signal 109a is high-frequency emphasized in a pre-emphasis circuit 117, subjected to modulation processing in a frequency modulator 118, and recorded on appropriate tracks of a floppy disk 121 through a recording amplifier 119 and a magnetic head 120. Ru.

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, according to the present invention, an audio signal to be recorded on a magnetic medium can be confirmed by being heard as audio from an audio output device before being recorded on the magnetic medium. Be able to do that. Therefore, it is no longer necessary to play back the audio signal recorded on the magnetic medium and check its content as in the past, and it is possible to easily modify the audio content recorded on the magnetic medium in a short time. You can do it.

Further, when the audio output device reproduces the sound recorded on the magnetic medium, the power supply to the magnetic recording device is stopped, so the power consumption of the entire device is reduced, and energy saving can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional audio recording device, and FIG. 3 is a block diagram showing a conventional audio reproducing device. In the figure, 103.105a is an audio signal, 106 is a time axis conversion device, 107 is an A/D conversion word, 107a is a digital audio signal, 108 is RAM1, 108a is a digital audio signal, 109 is a D/A converter, 110 is an address counter, 111 and 112 are clock generators, 113 is a clock changeover switch, 114 is an audio signal changeover switch, 115 is a magnetic recording device, 116 is an audio output device, 121 is a floppy disk, 126 is a system controller, 127 is a 128 is a recording start switch, 129 is an audio signal start switch, 130 is a power supply unit, 130a is a power supply signal, and 131 is a power supply switch.

Claims (1)

[Claims] (a) an A/D converter that converts an input audio signal, which is an analog signal, into a digital audio signal; (b) a memory into which the digital audio signal is written; (c) reading from the memory. a D/A converter that converts the digital audio signal into an analog audio signal; (d) an address counter that specifies the address of the memory to be written/read; and (e) a rotating magnet that converts the analog audio signal a magnetic recording device that records on a recording medium; (f) an audio output device that outputs the analog audio signal as audio; and (g) a switch that outputs the analog audio signal to the magnetic recording device and audio output. (h) when writing the digital audio signal to the memory, the digital audio signal is written to the memory in synchronization with a first clock signal, and the audio is output from the audio output device; Sometimes, a digital audio signal is read out from the memory in synchronization with the first clock signal and the D/A signal is read out from the memory.
When sending the converted analog audio signal to an audio output device via the audio signal changeover switch and recording the analog audio signal on a magnetic recording device, first, power is supplied to the magnetic recording device whose power supply has been stopped by a power supply stop signal. A signal is output to start power supply, and then a digital audio signal is read out from the memory in synchronization with a second clock signal having a higher frequency than the first clock signal, and the D/A converted analog audio signal is read out from the memory. a system controller that sends the audio signal to the magnetic recording device via an audio signal changeover switch; and (i) an input device that sets conditions for selecting whether the input audio signal is output as audio or magnetically recorded in the system controller. An audio recording device characterized by: