JPS601608A - Digital sound recorder - Google Patents

Abstract

PURPOSE:To obtain the ideal frequency characteristics by using a photoelectric converting means which receives the reflected beam light sent from a reflecting film of a flat plate type vibrating means which vibrates with the acoustic signal with a light reflecting film formed on the surface in the form of the replacement in the one-dimensional direction and converts the beam light into electric signals. CONSTITUTION:The beam light sent from a laser light source 11 is irradiated approximately at the center of a vibrating film 12, and this reflected light is irradiated at the center of a CCD sensor 14 through an optical position enlarging device. When the film 12 is vibrated in proportion to the acoustic amplitude, the optical path of the laser light reflected by the film 12 is changed. Thus the vibration of the film 12 is converted into the position displacement of light in the one-dimensional direction. The light enlarged by a displacement position enlarging device 13 scans the sensor 14 in the one-dimensional direction. The sensor 14 is equal to a so-called one-dimensional image sensor containing an N-bit photoelectric converting part and an N-bit transfer channel part. This sensor is turned toward the surface which is scanned by the light.

Description

[Detailed description of the invention] The present invention relates to a digital recording device.

BACKGROUND ART In recent years, digital recording methods have come into use as sound recording/playback systems, and excellent playback quality has come to be obtained. As shown in the block diagram of Fig. 1, this recording device converts the sound from the microphone 1 into an all-electric signal during recording, amplifies it to a certain level with the amplifier [2, and then sends it to the A/D converter 3. After converting the analog signal into a fully digital signal, the signal processing device 4 performs processing such as filtering and code conversion, and the signal is recorded on a recording device 5 such as a magnetic tape. This conventional recording device has the disadvantage that the SZN ratio and frequency characteristics of the entire recording system are limited by the 8/N ratio and frequency characteristics of the microphone 1 and the amplifier 2.

The purpose of the present invention is to directly convert sound into digital signals without using conventional microphones or amplification devices.
An object of the present invention is to provide a digital recording device Zk that can obtain an ideal 8/N ratio and frequency characteristics.

The digital recording device of the present invention vibrates according to the acoustic signal and has a reflective film on the surface. A flat vibration means provided, a light source that irradiates the reflective film of the vibration means with a thin beam from an oblique direction, and a reflected beam from the reflective film is received as a displacement in the dimensional direction and converted into an electrical signal. It is composed of a charging converting means, a recording means for counting all the blades of the charging converting means, and recording it digitally (No. 3).

The present invention will be explained in detail below with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the invention.

In this invention, a flat plate-shaped vibrating membrane 12 that vibrates in proportion to the acoustic amplitude and has an original reflective film formed on its surface is used, but this original reflective film can be coated with metal or the like by full vapor deposition. good. In this embodiment, in addition to the vibrating membrane 12, a laser light source 11 that irradiates the vibrating membrane 12 with a narrow beam is provided.
, a displacement magnifying device 13 that optically magnifies the amount of positional displacement of the reflective film from the vibrating membrane 12 and is composed of a combination of convex lenses, and a CCD that extracts the original positional fluctuation from these original systems as an electrical signal. sensor 14 and this CCD sensor 1
A waveform shaping circuit 15 that shapes all the output signals from the CC
A counting device 16 that counts the transfer lock signal CL1' of the D sensor 14, and a digital signal processing device 17 that performs code conversion and filtering of the counting data of this counting device 16.
, a recording device 18 that records digital signals, and a timing generator 17 that generates a transfer lock signal and various timing signals. It consists of the following.

1. First, the beam source from the laser light source 11 is irradiated to approximately the center of the vibrating membrane 12, which is treated with metal for total reflection, and the beam reflected by this vibrating membrane 12 is subjected to an elementary displacement amount expansion. The light passes through the entire device 13 and is irradiated to the center of the CCD sensor 14. When this vibrating membrane 12 vibrates in proportion to the acoustic amplitude, the optical path of the laser beam reflected by this vibrating membrane 12 changes, and the vibration of the vibrating membrane 12 can be converted into an original displacement in one-dimensional direction. can. The displacement magnifying device 13 is designed to fully expand the original positional displacement, but if the original positional displacement reflected by the vibrating membrane 12 is sufficiently large, the displacement magnifying device 13 can also be omitted. The source whose displacement is magnified by the displacement magnifying device 13 scans the COD sensor 14 in all dimensional directions. This CCD sensor 14 is a so-called -dimensional image sensor 17. It is composed of an N-bit charge conversion section and an N-bit transfer channel section, and is directed toward the original scanning surface. The number of bits of this CCD sensor 14 is determined according to the required signal resolution; for example, if 8-bit resolution is required, 256
bit or more, if 10 bit resolution is required, 10
The number of bits may be 24 or more.

For convenience, the amount of displacement of the vibrating membrane 12 in a certain direction from the resting state will be referred to as "displacement to the + side", and the amount of displacement in the opposite direction will be referred to as "displacement to the + side".
If we refer to this as “displacement to the − side”, the vibration membrane 12 will move toward (−
) When the vibrating membrane 12 is displaced to the (-1-1) side, the original position is moved to the output side of the CCD sensor 14, and when the vibrating membrane 12 is displaced to the (-1-1 side, the original position is moved to the side opposite to the output side of the CCD sensor 14. The beam source irradiated to this CCD sensor 14 is
This COD sensor 4 is converted into an electric signal in the charge conversion section, and is transferred to the transfer channel section of the CCD sensor 14 by the sampling signal S2, and the transfer lock signal S1
is output from the blade terminal A of the COD sensor 4. If the beam source is irradiated near the output of the COD sensor, the signal will be output with a small number of transfer locks,
Conversely, if the beam source is irradiated to the side opposite to the output, many transfers and locks are required before the signal is output. The transfer lock number is obtained by starting counting in the counting device 16 using the sampling signal S2 in response to the transfer lock signal 81, and ending the counting based on the fcgI signal output from the COD sensor 4. This C
The signal output from the OD sensor 4 is sent to the waveform shaping device 1
After being converted into a pulse signal by the counter 5, the counting device 16
is input. The counting data of this counting device 16 is CO
The entire amount of positional displacement of the beam source irradiated onto the D sensor 4 is shown, and the acoustic signal amplitude is converted into a digital amount. Furthermore, this count data is completely equivalent to the data obtained by the conventional A/D converter 3. Therefore, after this, the counting data of the counting device 16 can be subjected to all note processing such as code conversion and filtering by the Ig processing device 17, and can be recorded by the recording device 18 in the same manner as in the conventional case.

According to the present invention, since it is possible to completely digitally convert and record sound without using conventional microphones or amplifiers, it is possible to easily realize unprecedented S/N ratio, frequency characteristics, distortion rate characteristics, etc. I can do it.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional digital recording device, and FIG. 2 is a block diagram of an embodiment of the present invention. In the figure, 1°°゛°: Microphone, 2: Amplifier, 3: A/I) converter, 4:
・Signal processing device, 5.18...Recording device, 11
... Laser light source, 12 ... Vibration membrane,
13... Displacement magnifying device, 14...C
CD sensor, 15... Waveform shaping circuit, 16...
...Counting device, 17...Digital 1g processing device, 19...Timing generator, Sl
. . . Transfer data, S2 . . . Sampling signal.

Claims (1)

[Claims] A reflective film on the surface that vibrates due to acoustic signals? The system includes nine plate-shaped vibration means, a light source that irradiates the reflection film of the vibration means with a thin beam from an oblique direction, and receives the reflection beam from the reflection film as a one-dimensional displacement and converts it into an electrical signal. A digital recording device includes a charge converting means for converting the charge, a recording means for counting all the blades of the charge converting means and recording it as a digital signal, and a digital recording device.