JPS582420B2 - Shingoukirokuhoushiki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal recording method using an acousto-optic filter such as a Te02 crystal.

Acousto-optic filters deflect only light in a specific color spectrum using a specific ultrasonic frequency, and are characterized by high-speed color separation.

Therefore, the color spectrum of the object can be extracted continuously on the time axis.

The present invention allows this continuous color spectrum signal on the time axis to correspond to general signals (eg, video signals, audio signals).

The recording method of the present invention is characterized by recording and reading out three dimensions of hue, intensity, and position on recording paper or a recording plate (transmissive type or reflective type).

FIG. 1 shows an embodiment of the signal recording method according to the present invention.

1 is a white light source with a broad and flat spectrum, 2 is a parallel optical lens that converts the light rays from light source 1 into parallel rays, 3 is a parallel ray, 4 is an acousto-optic filter, and 6 is an acousto-optic filter passed through. 6 is a light stopper for blocking the rectilinear parallel light 5; 7 is the parallel light diffracted by the acousto-optic filter 4 and includes only the necessary light spectrum; 8 is a focusing lens for focusing the diffracted light 7 , 9 is a signal processor for an acousto-optic filter, and 1 is a wideband AM modulator.
0 is an FM chirp wave input terminal, 11 is a recording signal input terminal, 12 is a recording point where the diffracted light 7 is focused by a focusing lens 8,
13 is a recording paper or a recording filter for recording the hue of the diffracted light 7 and the amplitude of the amount of light energy; 14 is a scanning direction;

FIG. 2 shows a signal waveform for the recording system shown in FIG. 1, where a is a control voltage waveform for transmitting an FM chirp signal, and the voltage level corresponds to the frequency of the signal to be oscillated.

b is an FM chirp signal applied to the terminal 10, which is caused to oscillate by the control voltage wave a.

The frequency range is within the signal band used by the acousto-optic filter 4.

C is a recording signal such as a video signal or an audio signal, and this signal is recorded on the recording paper 13 as hue and light amplitude.

d is a modulated signal modulated by the recording signal C using the FM chirp signal b as a carrier wave, which is generated by the signal processor (wideband AM modulator) 9 and applied to the acousto-optic filter 4.

The energy level of this modulated signal d is sufficient to produce the filter effect 1 of the acousto-optic filter 4 and is within its dynamic range.

The operation in FIG. 1 will be explained below.

A parallel light beam 3 from a white light source 1 is incident on an acousto-optic filter 4 at an optimal angle.

The acousto-optic filter 4 has an optimal incident angle structurally, which is an angle at which interaction between ultrasonic waves and light occurs efficiently.

Light incident at this angle interacts with the ultrasonic waves within the TeO2 crystal medium constituting the acousto-optic filter, but in that case, it interacts only with light having a specific wavelength of the incident light.

As a result, only the light 7 with a specific wavelength is diffracted and deflected,
The light travels on a different path from the straight light 5.

If the intracrystal ultrasonic frequency at this time is changed to another frequency, the wavelengths of light that cause interaction will be different, and only the light with different wavelengths will be diffracted and deflected.

Further, at this time, the relationship between the amount of energy of the ultrasonic wave existing in the crystal and the intensity of the diffracted light has a one-to-one correspondence, and within a narrow dynamic range, it is a linear relationship.

Therefore, the intensity of the diffracted light 7 is approximately proportional to the amplitude of the recording signal C.

The diffracted light 7 deflected by the acousto-optic filter 4 in this way undergoes wavelength selection by the frequency of the electric signal applied to the acousto-optic filter 4, the intensity of the deflected light is changed by the ultrasonic energy in the crystal medium, and the polarized light 7 is The direction can be made constant by devising the structure of the acousto-optic filter 4.

The FM chirp signal b applied to the terminal 10 and the recording signal C applied to the terminal 11 are converted into FM-
The AM wave d is applied to the acousto-optic filter 4.

The spectral distribution of the diffracted light 7 due to this signal d is almost the same as the recording signal C within one cycle T of the FM chirb wave b.

This diffracted light 7 is focused to record the hue and light intensity at a point 12 on the recording film 13.

At the same time, the recording film 13 is moved and scanned so that the recording point 12 becomes a new point on the recording film 13 within one cycle T of the FM chirped wave b.

This is to prevent rays of the same wavelength from being recorded at the same point.

FIG. 3 shows a readout system corresponding to this recording system.

In FIG. 3, 15 is a white parallel light beam, 16 is a recording film scanning direction, 18 is a readout point on the recording film 16, and 19 is a white parallel light beam.
is the transmitted light of the film 16 and includes color spectra corresponding to a large number of recording signals.

20 is an acousto-optic filter, 21 is an FM chirb wave input terminal, 22 is an acousto-optic filter for straight passing light, 23 is a light stopper for blocking the straight passing light 22, 24 is diffracted light with a narrow spectrum width, 25 is a photoelectric conversion The sensitivity of the device is constant depending on the wavelength of light used.

26 is a signal processor which also has the role of restoring the original recorded signal.

27 is a recording signal output terminal.

The white parallel light beam 15 has a broad and flat spectrum, and the recording film 16 is irradiated with this light beam.

Further, this recording film 16 is traveling along a scanning direction 17, and this traveling direction coincides with the traveling direction 14 in the case of the writing system shown in FIG.

The recording film 16 is of a transmission type, and the transmitted light 19 of the recording film 16 has a large number of color spectra depending on the hue and transmittance of one point 18 on the recording film 16.

The transmitted light 19 passes through an acousto-optic filter 20 (which may be the same as the acousto-optic filter 4 in FIG. 1). The light 19 is separated into color-separated diffracted light 24 and straight light 22 on the time axis.

The cycle of this FM chirp wave is synchronized with the film advancing speed.

The diffracted light 24 changes in hue and amplitude over time, and is then converted into an electrical signal by a photoelectric converter 25.

This electrical signal corresponds to the original recording signal, and is returned to the original recording signal by the signal processor 26 and output from the terminal 27.

This signal processor 26 is unnecessary when a reflective recording film is used instead of the transmissive recording film 16 and the reflected light therefrom is passed through the acousto-optic filter 20.

The method of the present invention has been described above. According to the present invention, since hue is also used for signal recording, it has the advantage that the recording density is improved compared to the conventional method.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the signal recording method according to the present invention, FIG. 2 is a waveform diagram for explaining the embodiment of FIG. 1,
FIG. 3 is a block diagram showing an embodiment of the signal reproducing system according to the present invention. 1... White light source, 2... Lens, 3,
15... White parallel rays, 4,20...
Acousto-optic filter, 5, 22... straight light, 6,
23...Light stopper, 7,24...Diffracted light, 8...Focusing lens, 9,26...
・Signal processor, 10, it, 21... Signal input terminal, 12... Recording point, 13, 16...
...Recording medium, 14,17...Scanning direction, 1
8...readout point, 19...recording medium transmitted light, 25...photoelectric converter, 27...
・Signal output terminal.

Claims (1)

[Claims] 1 A modulated signal obtained by modulating a signal whose frequency changes over time with a signal to be recorded is applied to an acousto-optic filter, and a signal corresponding to the modulated signal is obtained from the multispectral light applied to the acousto-optic filter. A signal recording method characterized by obtaining diffracted light, focusing the diffracted light, and recording it on a recording medium.