JP2803958B2 - Image information recording device and image information reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information recording apparatus and an image information reproducing apparatus and, more particularly, to a PROM (Pockles Readout) device capable of selectively and optically recording image information repeatedly appearing at a constant period. Optical Modula
The present invention relates to an image information recording apparatus utilizing tor) and an image information reproducing apparatus for reproducing image information recorded in the image information recording apparatus.

[0002]

2. Description of the Related Art Various image pickup devices such as an image pickup tube and a two-dimensional CCD array have been put into practical use. In these image pickup apparatuses, light from an object to be imaged is converted into an electric signal to record and reproduce an image. On the other hand, there is also a strong demand for selectively capturing an image that repeatedly appears at a specific frequency in the incident image light, for example, an image formed by light that emits light and blinks at a constant cycle. There is a strong demand for the development of an imaging device that can clearly capture spark discharge patterns generated in transformers and transformers. However, imaging devices that are currently in practical use receive all light incident on the photoelectric conversion unit and are photoelectrically converted.
Since the light generated by the spark discharge and the light from the background are both photoelectrically converted, the image due to the spark discharge and the background image are superimposed, and it was not possible to clearly capture only the image due to the spark discharge. .

On the other hand, as an image pickup device, a PROM device which is a kind of a spatial light modulator is known. Where PROM
The element generates a charge corresponding to the light intensity of the writing light by a photoconductive effect, holds the generated charge as a polarization charge, and a polarization state of the reading light according to the polarization charge held by the Pockels effect. Means an element that changes This PROM element includes, for example, a Bi ₁₂ SiO ₂₀ single crystal plate, and image information is written using a photoconductive effect, and image information is read using a Pockels effect.

That is, when writing image information, PR
In the state where a DC bias voltage is applied to the OM element, write light is irradiated to form a polarization charge corresponding to image information inside the element to record an image. Light that is linearly polarized in a biased or non-biased state is projected onto a PROM element, and image information is read out using the Pockels effect based on polarization charges formed inside the PROM element.

If an image recording / reproducing apparatus using this PROM element is used, it is possible to convert an incoherent light image into a coherent light image or to perform an optical Fourier transform, thereby achieving various advantages in image analysis. You.

When the above-described PROM element is used as an image information recording medium, various types of optical image information processing can be performed on a recorded image. is there. Therefore, if only an image that repeatedly appears at a specific frequency among various incident images can be recorded in the PROM element, not only an image that appears periodically can be recorded, but also the unique characteristics of the PROM element can be used. Various advantages are achieved.

However, in a conventional image recording apparatus for recording image information in a PROM element, both an image of a background portion and an image appearing at a fixed period are recorded in a superimposed manner.
Images repeatedly appearing at a constant cycle cannot be selectively recorded, and as a result, periodic images cannot be selectively and clearly recorded and reproduced.

Accordingly, an object of the present invention is to selectively print an image which repeatedly appears at a specific cycle among various incident images.
It is an object of the present invention to provide an image information recording device capable of recording on an image information recording element such as an OM element and an image information reproducing device for reproducing image information recorded on the image information recording device.

[0009]

According to Means for Solving the Problems The present invention generates a charge corresponding to the light intensity of the writing light, and the image recording element for holding the generated electric charges as polarized charges, light from a subject the Imaging means for making the image information recording element incident as writing light; and an image of the subject formed by the writing light.
Of the images, the change in light intensity of the writing light that forms the required image
AC bias voltage applying means for applying an AC bias voltage having the same frequency as the frequency to the image information recording element, wherein an image of a subject formed by the writing light is provided.
, An image information recording apparatus characterized in that the necessary image is spatially separated and extracted from the image information.

Further, according to the present invention, a charge corresponding to the light intensity of the writing light is generated, the generated charge is held as a polarization charge, and the reading light is modulated according to the held polarization charge. a spatial light modulator, an imaging unit to be incident as the writing light light from a subject to the spatial light modulator, prior to
Of the image of the subject formed by the writing light,
Same as the frequency of the light intensity change of the writing light to form the required image
AC bias voltage applying means for applying an AC bias voltage having the following frequency to the spatial light modulation element; readout light incidence means for causing readout light to enter the spatial light modulation element; and readout emitted from the spatial light modulation element. Reading light detecting means for detecting light, and an object formed by the writing light.
Read the required image spatially separated from the body image
Image information playback apparatus is obtained, characterized in that to.

The image information recording apparatus and the image information reproducing apparatus according to the present invention further include a frequency detecting means for detecting a frequency of an intensity change of an image whose intensity changes at a constant frequency among the images of the object. In this case, the AC bias voltage applying means applies an AC bias voltage having the same frequency as the frequency detected by the frequency detecting means to the image information recording element or the spatial light modulation element.

Further, the image information recording apparatus and the image information reproducing apparatus according to the present invention may further include a phase adjusting means for changing a phase of the AC bias voltage applied by the AC bias voltage applying means.

Further, the image information recording apparatus and the image information reproducing apparatus according to the present invention may further comprise a DC bias voltage applying means capable of applying a DC bias voltage to the image information recording element or the spatial light modulation element. it can.

The image information recording element or the spatial light modulation element generates a charge corresponding to the light intensity of the writing light, and holds the generated charge as a polarization charge. A spatial light modulation element that changes the polarization state of the readout light according to the condition can be used.

Such a space that generates charges corresponding to the light intensity of the write light, holds the generated charges as polarization charges, and changes the polarization state of the read light according to the held polarization charges. The light modulation element generates a charge corresponding to the light intensity of the writing light by a photoconductive effect, holds the generated charge as a polarization charge, and generates a charge of the reading light according to the polarization charge held by the Pockels effect. An element that changes the polarization state can be used.

Further, a charge corresponding to the light intensity of the writing light is generated by the photoconductive effect, the generated charge is held as a polarization charge, and the polarization of the reading light is changed according to the polarization charge held by the Pockels effect. Liquid crystal can be further provided in addition to the element for changing the state.

Further, the spatial light modulator generates a charge corresponding to the light intensity of the write light, holds the generated charge as a polarization charge, and generates a charge of the read light in accordance with the held polarization charge. A spatial light modulation element that changes the transmittance may be used.

Further, the image information recording element or the spatial light modulation element may be configured to include a material having a photoconductive effect as a recording material and a liquid crystal as a reading material.

[0019]

When writing light of intensity I (t) is perpendicularly incident on a crystal plane of a material having a photoconductive effect such as a PROM element, the amount of charge Q accumulated on the crystal surface of the PROM element becomes
Current i (t) flowing in the crystal in a direction perpendicular to the crystal plane
Is represented by the following equation.

Q = ∫i (t) dt (1) This current i (t) is represented by the product of the charge density q (t) of the carrier excited by the writing light and the moving speed. Since the speed is proportional to the applied electric field E (t), if the bias voltage applied to the PROM element is V (t), the current i
(T) is represented by the following equation.

I (t) ∝q (t) E (t) ∝q (t) V (t) (2) Further, the charge density q (t) of the carrier is expressed as It is proportional to the light intensity I (t).

Q (t) ∝I (t) (3) Accordingly, the charge amount Q accumulated on the crystal surface of the PROM element
Is represented by the following equation.

Q∝∫I (t) V (t) dt (4) First, considering the case where a DC bias voltage V (t) is applied to the PROM element, the bias voltage V (t) is constant. (4) is given by the following equation: Q∫V∫I (t) dt (5) The charge amount Q accumulated on the crystal surface of the PROM element is the time integral of the light intensity I (t) of the writing light. And does not depend on the time-varying component of the writing light.

Next, the AC bias voltage V is applied to the PROM element.
Consider the case where (t) = V ₀ cos 2πωt is applied.

The light intensity I (t) of the writing light is expressed as I (t) = I ₀
Assuming that (cos 2πω′t + 1), the charge amount Q accumulated on the crystal surface of the PROM element is expressed by the following equation.

Q∝I ₀ V ₀ ∫cos 2πωt (cos 2 πω′t + 1) dt (6) Now, when the writing light is continuous light whose light intensity is constant with respect to time, that is, Considering the case where ω ′ = 0, equation (6) is as follows.

Q∝2I ₀ V ₀ ∫cos 2πωtdt = (I ₀ V ₀ / πω) sin (2πωt) (7) As is apparent from the equation (7), when an AC bias voltage is applied to the PROM element, However, even if continuous light is applied, the amount of charge Q accumulated on the crystal surface of the PROM element only slightly increases and decreases. Therefore, when an AC bias voltage is applied to the PROM element, PR
The OM element has almost no sensitivity to continuous light.

Next, when the frequency of the writing light coincides with the frequency of the AC bias voltage applied to the PROM element,
That is, when ω ′ = ω, equation (6) becomes as follows.

Q∝I ₀ V ₀ ∫cos 2πωt (cos 2πωt + 1) dt = I ₀ V ₀ ((t / 2) + (１ ／ πω) sin 2πωt + (1 / 8πω) sin 4πωt) (8) ( The first term of the expression 8) is the time t and the light intensity I of the writing light.
This is a term proportional to the product of the I ₀ component of (t) and the V ₀ component of the AC bias voltage V (t). Accordingly, when an AC bias voltage is applied to the PROM element and the frequency of the writing light is equal to the frequency of the AC bias voltage, a charge corresponding to the light intensity of the writing light is deposited on the crystal surface of the PROM element. As a result, the PROM element is sensitive to light whose light intensity changes in synchronization with the AC bias voltage.

When an AC bias voltage is applied to the PROM element as described above, the PROM element has no sensitivity to continuous light, but does not respond to light whose light intensity changes in synchronization with the AC bias voltage. If the light incident on the PROM element from the object to be imaged is composed of continuous light and light whose light intensity changes in synchronization with the AC bias voltage, the light is synchronized with the AC bias voltage. The charge generated by the light whose intensity changes can be selectively accumulated on the crystal surface of the PROM element. Therefore, image information synchronized with the AC bias voltage applied to the PROM element can be selectively recorded on the PROM element.

When a plurality of pieces of image information appearing at various periods enter the PROM element, image information synchronized with the applied AC bias voltage is selectively recorded on the PROM element. Therefore, by changing the frequency of the AC bias voltage applied to the PROM element, it is possible to selectively record only image information having the same frequency as the AC bias voltage among a plurality of image information that changes at various frequencies.

Further, there is provided frequency detecting means for detecting a frequency of an intensity change of an image whose intensity changes at a constant frequency in an image of the object to be imaged, and an alternating current having the same frequency as the frequency detected by the frequency detecting means is provided. By applying a bias voltage to the PROM element by the AC bias voltage applying means, selective recording of image information whose intensity changes at a constant frequency can be performed even more effectively.

Further, by providing a DC bias voltage applying means capable of applying a DC bias voltage to the PROM element in addition to the AC bias voltage applying means, in addition to the image information whose intensity changes at a constant frequency, the DC bias voltage is applied to the PROM element. Background image information can also be superimposed and recorded. Therefore, the position of the image whose intensity changes at a constant frequency on the object to be imaged can be accurately known.

At this time, first, the AC bias voltage is set to PRO
After image information whose intensity changes at a constant frequency applied to the M element is selectively recorded in the PROM element, a DC bias voltage is applied to the PROM element to superimpose the background image information and record it in the PROM element. Alternatively, an AC bias voltage and a DC bias voltage may be simultaneously applied to the PROM element to selectively record the image information whose intensity changes at a constant frequency to the PROM element and to store the background image information in the PROM element.
Recording on the ROM element may be performed simultaneously.

By further providing a phase adjusting means capable of changing the phase of the AC bias voltage applied by the AC bias voltage applying means, a difference between image information whose intensity changes at a constant frequency and the AC bias voltage is provided. Even if there is a phase difference φ, selective recording of image information whose intensity changes at a constant frequency can be effectively performed.

Writing light: I (t) = I ₀ (cos 2πωt +
1) and AC bias voltage: V (t) = V ₀ cos 2πωt
In the case where there is a phase difference φ between Equation (5) and Equation (6), Equation (6) can be expressed as follows.

Q∝I ₀ V ₀ ∫cos 2πωt (cos (2πωt + φ) +1) dt = I ₀ V ₀ ((1/2) cos φ · t + (1 / 2πω) sin 2πωt + (1 / 8πω) sin ( 4πωt + φ)) ... (9 ) (9) I 0 component, V ₀ component of the AC bias voltage V (t) of the first term time t, the write light intensity I (t) of the equation, and cos phi and Is a term proportional to the product of Therefore, even when the frequency of the writing light is equal to the frequency of the AC bias voltage, the sensitivity of the PROM element depends on the phase difference φ between the writing light and the AC bias voltage, and the phase difference φ is φ = Π / 2 or 3/2 · π, the PROM element becomes
There is no sensitivity to light whose light intensity changes at the same frequency as the AC bias voltage. When the phase difference φ does not take a value such as φ = π / 2 or 3/2 · π, the PROM element is sensitive to light whose light intensity changes at the same frequency as the AC bias voltage. But the phase difference φ is P when the value of cos φ is | cos φ | = 1.
The sensitivity of the ROM element is maximized.

Therefore, a phase adjusting means capable of changing the phase of the AC bias voltage applied by the AC bias voltage applying means is further provided, and by adjusting the phase difference φ, the intensity thereof changes at a constant frequency. The selective recording of the image information to be performed can be effectively performed.

The above-described image information recording operation will be described in detail. An image information recording element which generates a charge corresponding to the light intensity of the writing light and holds the generated charge as a polarization charge.
And generating a charge corresponding to the light intensity of the writing light, holding the generated charge as a polarization charge, and modulating the readout light in accordance with the held polarization charge. P with both Pockels effects
The operation of the present invention has been described by taking a ROM element as an example. However, a material having a photoconductive effect but not a Pockels effect, GaAs single crystal, GaAs film, hydrogenated amorphous silicon film, amorphous silicon carbide film, amorphous selenium film, etc. Is used as a recording material for an image information recording element and a spatial light modulation element in the present invention, even in the case of using
It has the same function as the M element.

The spatial light modulator used in the image information reproducing apparatus generates a charge corresponding to the light intensity of the writing light, holds the generated charge as a polarization charge, and responds to the held polarization charge. A spatial light modulator that changes the polarization state of the readout light can be used.

As such a spatial light modulation element, for example, a PROM element can be mentioned. As described above, the PROM element generates a charge corresponding to the light intensity of the writing light by the photoconductive effect, holds the generated charge as a polarization charge, and responds to the polarization charge held by the Pockels effect. When a PROM element is used as a recording material for image information, the polarization state of the reading light can be changed by the PROM element itself, and other reading elements can be used. It is not necessary to further provide this material in addition to the recording material.

A reading material that changes the polarization state of the reading light in accordance with the polarization charge includes a liquid crystal.

When a liquid crystal whose reading light polarization state changes according to an applied voltage such as a twisted nematic liquid crystal (TNLC) is further provided in addition to the PROM element, an AC bias applied to the PROM element at the time of writing is provided. The voltage value of the voltage can be reduced, so that the configuration of the AC bias voltage applying means can be simplified. The applied voltage required to obtain the same polarization change state is P
Since the value of the AC bias voltage applied to the PROM element at the time of writing is reduced by about two orders of magnitude or more compared to the ROM element, the amount of charge accumulated and held on the crystal surface of the PROM element is reduced. At least, by applying an electric field based on the charges to the liquid crystal, the polarization state of the reading light can be changed by the liquid crystal as needed.

Furthermore, GaAs single crystal, GaAs, which is a material having a photoconductive effect but not a Pockels effect.
When a film, a hydrogenated amorphous silicon film, an amorphous silicon carbide film, an amorphous selenium film or the like is used as a recording material for an image information recording element and a spatial light modulation element in the present invention, a twisted nematic is used as a reading material. A liquid crystal such as a liquid crystal (TNLC) whose polarization state of readout light changes according to an applied voltage can be used. Also in this case, since the required polarization change state of the reading light can be obtained with a small applied voltage, the value of the high-voltage bias voltage applied to the recording material can be reduced. It can be simple.

As described above, as the spatial light modulator, the electric charge corresponding to the light intensity of the write light is generated, the generated electric charge is held as the polarization charge, and the read light is generated in accordance with the held polarization charge. When a spatial light modulator that changes the polarization state is used, a PR provided in an image information reproducing apparatus is used.
The reading light incident means for inputting the reading light to the OM element includes:
Preferably, a device for injecting linearly polarized light using a polarizer or the like is used, and the reading light detecting means for detecting the reading light emitted from the PROM element preferably detects the polarization state of light such as an analyzer. A device equipped with an element capable of being used is used.

Further, as a spatial light modulator used in the image information reproducing apparatus, a charge corresponding to the light intensity of the writing light is generated, and the generated charge is held as a polarization charge.
A spatial light modulation element that changes the transmittance of readout light in accordance with the polarization charge held can be used.

As a material for reading which changes the transmittance of the reading light in accordance with the polarization charge, there is a liquid crystal. When a liquid crystal such as a polymer-dispersed liquid crystal (PDLC) whose transmittance of readout light changes according to an applied voltage is used, there is no need to use polarized light for the readout light, so that no polarizer or analyzer is required. Thus, the configuration of the image information reproducing apparatus is simplified.

The liquid crystal whose reading light transmittance changes according to the applied voltage of this polymer dispersed liquid crystal (PDLC) or the like is P
The present invention relates to a GaAs single crystal, a GaAs film, a hydrogenated amorphous silicon film, an amorphous silicon carbide film, an amorphous selenium film, etc., which may be provided in addition to the ROM element and have a photoconductive effect but no Pockels effect. When used as a recording material for an image information recording element and a spatial light modulation element in the above, it may be used as a reading material.

Next, the writing time T _W of the image information will be examined. When the frequency of the image information matches the frequency of the AC bias voltage, the writing time T _W can be set in any manner.

On the other hand, if there is a deviation between the frequency ω ′ of the image information and the frequency ω of the AC bias voltage, the writing time T
_The question is how to set _W.

In the equation (6), the case where ω ≠ ω 'is considered.

Q∝I ₀ V ₀ ∫ (cos 2πωt + cos 2πωt · cos 2πω′t) dt = I ₀ V ₀ ((1 / 2πω) sin 2πωt + (1 / 2π (ω + ω ′)) sin 2π (ω + ω ′) t + (1 / 2π (ω−ω ′)) sin 2π (ω−ω ′) t) (10) In the expression (10), in the case of ω 1 to ω ′, the third term is slower than other terms. Varies and the amplitude is large. Therefore, the third
If the writing of image information ends faster than the cycle of the term,
Recording of image information becomes possible. In this case, if the write time T _W is set so as to satisfy the following equation, the PROM element has sensitivity.

Ω−ω ′ <1 / T _W (11)

[0054]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a sectional view for explaining a PROM element used in the image information recording apparatus and the image information reproducing apparatus according to the present invention.

An insulating layer 3 made of quartz glass is provided on both sides of a charge generation holding layer 4 made of a single crystal of Bi ₁₂ SiO _20.
And 5 are provided, and ITO (In) is provided outside the insulating layers 3 and 5.
transparent electrodes 2 and 6 made of diumTin Oxide)
Substrate glasses 1 and 7 made of quartz glass are provided outside the transparent electrodes 2 and 6, respectively, to form a PROM element 16.

Image information writing light is incident on the PROM element 16 from the direction of arrow a. Since Bi ₁₂ SiO ₂₀ has sensitivity (photoconductivity) to electromagnetic waves having a shorter wavelength than blue light, light in the blue region, X-rays, or the like is used as writing light. When the writing light is incident, charge carriers (electrons and holes) corresponding to the writing light intensity are generated in the charge generation holding layer 4 by a photoconductive effect. When a bias voltage is applied between the transparent electrodes 2 and 6 via the terminals 8 and 9 in response to the incidence of the writing light, the charge carriers generated by the photoconductive effect cause the electric field generated in the charge generation protective layer 4 to be changed. As a result, it drifts in the charge generation protection layer 4 and is polarized on the surface of the charge generation protection layer 4. The polarized charges are held as polarized charges on both surfaces of the charge generation protection layer since the insulating layers 3 and 5 are provided on both surfaces of the charge generation protection layer 4, respectively.

In the present invention, between the transparent electrodes 2 and 6,
An AC bias voltage having a frequency corresponding to the frequency of the image information to be recorded is applied. The AC bias voltage may have various waveforms such as a sine wave, a triangular wave, and a rectangular wave. As described above, when an AC bias voltage corresponding to the frequency of the image information is applied, the light intensity of the image information, that is, the charge proportional to the incident light intensity is held on the surface of the charge generation holding layer 4 as polarization charge. The amount of the polarization charge and its spatial distribution are used as image information in the PROM element 16.
To record.

As described above, the PROM element 16 records the amount of polarization charge and its spatial distribution.
Image information having a gradation property is recorded in the ROM element 16.

It is to be noted that the information once recorded can be erased only by projecting blue light or an electromagnetic wave having a shorter wavelength on the PROM element 16 with the transparent electrodes 2 and 6 short-circuited.

When a polarization charge is formed on the crystal surface of the Bi ₁₂ SiO ₂₀ single crystal, an electric field having an intensity corresponding to the polarization charge is formed, and birefringence occurs. Therefore, when reproducing recorded image information, when linearly polarized read light is incident on the PROM element 16, elliptically polarized light is emitted from the PROM element 16 in accordance with the amount of polarization charge. By measuring the light intensity of the readout light emitted from the analyzer, the amount of polarization charge can be measured. Therefore, by projecting through the imaging optical system after the analyzer, the PRO
Image information recorded on the M element 16 can be reproduced as an optical image. At this time, Bi ₁₂ SiO ₂₀
If light that does not produce a photoconductive effect in the single crystal, for example, red light, is used, image information can be reproduced without changing the distribution of polarization charges.

When reproducing image information, the PROM element 16
DC bias may be applied between the transparent electrodes 2 and 6, or the transparent electrodes 2 and 6 may be short-circuited. When a DC bias is applied between the transparent electrodes 2 and 6, the electric field generated by the polarization charge cancels the external electric field formed by the DC bias. Therefore, in the charge generation holding layer 4, the electric field is weak in the portion irradiated with the writing light, and the electric field becomes strong in the portion not irradiated, and the read image becomes a negative image of the written image information. When the transparent electrodes 2 and 6 are short-circuited, the electric field in the charge generation / holding layer 4 is only the electric field generated by the polarization electric field. Therefore, the electric field becomes stronger in the portion irradiated with the writing light, and becomes stronger in the portion not irradiated. Becomes weaker. Therefore, the read image is a positive image of the written image information.

As a display device for the reproduced image information, for example, a reproduced image from the PROM element 16 can be picked up by a TV camera and displayed on a CRT, or projected on a screen via a projection lens system. Can also be displayed. If necessary, an optical system for optical image processing such as optical Fourier transform may be provided, and a reproduced image from the PROM element 16 may be input to the optical system to perform appropriate image processing.

FIG. 2 shows a PROM element 56 with a liquid crystal used in the image information recording apparatus and the image information reproducing apparatus of the present invention.
FIG. 6 is a cross-sectional view for explaining the method.

A liquid crystal layer 50 is provided between the insulating layer 5 and the transparent electrode 6. When a material such as twisted nematic liquid crystal (TNLC) whose polarization state of read light changes according to an applied voltage is used for the liquid crystal layer 50, the transparent electrodes 2 and 6 of the PROM element 56 with liquid crystal are written at the time of writing. The voltage value of the AC bias voltage applied therebetween can be reduced, so that the configuration of the AC bias applying device for applying the AC bias voltage can be made simple and inexpensive. The applied voltage required to obtain the same polarization change state is about two orders of magnitude lower for the liquid crystal than for the PROM element 16 shown in FIG. Even if the voltage value of the AC bias voltage applied between 6 is reduced to reduce the amount of charge accumulated and held on the crystal surface of charge generation holding layer 4, an electric field based on the charge is applied to liquid crystal layer 50. The reason is that the polarization state of the readout light can be changed as necessary by the liquid crystal layer 50 by being applied.

In the device having this configuration, since the liquid crystal layer 50 modulates the reading light, a material having a photoconductive effect and having no Pockels effect can be used for the charge generation holding layer 4. . Therefore, in addition to the Bi ₁₂ SiO ₂₀ single crystal, a GaAs single crystal, a GaAs film, a hydrogenated amorphous silicon film, an amorphous silicon carbide film, an amorphous selenium film, or the like can be applied.

As the liquid crystal, a polymer dispersed liquid crystal (PDL)
When a material whose transmittance of readout light changes according to an applied voltage such as C) is used, it is not necessary to use light polarized as readout light, so that a polarizer or an analyzer becomes unnecessary, and image information reproduction is performed. The configuration of the device becomes simple.

As shown in FIG. 3, a liquid crystal-equipped PRO having a reflective layer 51 provided between a liquid crystal layer 50 and a charge generation / holding layer 4 is provided.
An M element 56 'can also be used. As the reflection layer 51, for example, a laminated film of TiO ₂ and SiO ₂ is used. Recording is performed by irradiating image information writing light from the direction of arrow A.
The reading light is made incident in the direction of arrow B, reflected by the reflection layer 51, emitted in the incident direction, and the image information is reproduced. With this element configuration, the readout term is the charge generation holding layer 4
This is advantageous in that the polarization charge distribution is not changed even if the reading light wavelength is arbitrarily selected.

If the insulating property of the liquid crystal layer 50 is sufficiently high and the polarization charge can be held on the surface of the charge holding / generating layer 4 by the liquid crystal layer 50, one or both of the insulating layers 3 and 5 may not be provided.

Next, the PROM element 16 or the PROM element with liquid crystal 56, 5 shown in FIGS.
An image information recording apparatus and an image information reproducing apparatus using 6 'and a method of recording and reproducing image information by these apparatuses will be described. (First Embodiment) FIG. 4 is a schematic diagram for explaining an image information recording apparatus and an image information reproducing apparatus according to a first embodiment of the present invention.

A method for recording and reproducing the image information of the spark discharge pattern generated in the high-pressure guy tube by the image information recording apparatus and the image information reproducing apparatus of this embodiment will be described.

When insulation failure or the like occurs in the guy tube of the transmission line, spark discharge occurs. This spark discharge is periodically generated at twice the frequency of the flowing current. Even if you try to image the spark discharge pattern in the daytime, sunlight will enter,
The spark discharge pattern cannot be clearly imaged. In such a case, if the image recording apparatus and the image reproducing apparatus according to the present invention are used, a spark discharge pattern can be clearly recorded on the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal.

The three power lines 10a to 10c are supported by the high-pressure guy pipes 11a to 11c. One power line 10b
The current detector 12 is mounted on the power line 10b, and the current detector 12 detects a current waveform flowing through the power line 10b. After the detected current waveform is amplified by the amplifier 13, the detected current waveform is supplied to the harmonic generator 14, and a signal having a frequency twice as high as the detected current is generated. The generated double-frequency signal is supplied to a high-voltage AC voltage generator 15 to generate a high-voltage AC bias voltage having the same phase as that of the current flowing through the power line 10b and having a frequency twice as high. Alternatively, it is applied to the PROM elements 56 and 56 'with liquid crystal.

Light generated by the generated spark discharge passes through a shutter 17, an imaging lens system 18 and a half mirror 19 to the PROM element 16 or the PROM elements 56,
6 '. PROM element 16 or PRO with liquid crystal
Since an AC bias voltage synchronized with the spark discharge repeatedly appearing at a constant cycle is applied to the M elements 56 and 56 ', no sunlight is recorded and only the image due to the spark discharge is PR.
The image is recorded in the OM element 16 or the PROM elements 56 and 56 'with liquid crystal. As a result, even if sunlight enters, only the image due to the spark discharge can be clearly recorded. In the present embodiment, the current detector 12 is provided on the power line 10b to detect the frequency and phase at which spark discharge occurs. However, if the frequency and phase of the current flowing through the power line 10b are known, the current detector 12 Is unnecessary.

Next, the PROM element 16 or the PR with liquid crystal
A reproduction optical system for reproducing images recorded on the OM elements 56 and 56 'will be described.

When reproducing the recorded image, the shutter 17 is closed and the high-voltage AC voltage generator 15 is turned off. The reading light is generated from the laser light source 20. As the reading light, light having a wavelength at which the photoconductive effect does not occur in the Bi ₁₂ SiO ₂₀ crystal used in the PROM element 16 or the PROM elements with liquid crystal 56, 56 ', for example, a wavelength of 633 nm
Of light. After that, the reading light generated from the laser light source 20 is converted into linearly polarized light by the polarizer 27. After that, the readout light passes through the reproduction light shutter 21 and further becomes an expanded parallel light beam through a beam expander 25 including an expander lens and a collimator lens.
The light enters the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal via the half mirror 19.

The reading light incident on the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal is
Alternatively, it becomes elliptically polarized light having an ellipticity according to the image information recorded in the PROM elements 56 and 56 'with liquid crystal, and
ROM element 16 or PROM elements 56, 56 'with liquid crystal
Inject from Therefore, this read light is transmitted to the PROM element 16.
Alternatively, by passing the light through the analyzer 22 disposed behind the PROM elements 56 and 56 'with liquid crystal, the PROM element 1
The image information recorded in the PROM element 6 or the PROM element with liquid crystal 56, 56 'is reproduced as an optical image having a light intensity distribution corresponding to the image information. This optical image is picked up by the TV camera 23 and displayed on the monitor 24.

With this configuration, the image information once recorded can be immediately reproduced, and a portable image recording and reproducing apparatus can be realized. Even during the daytime when sunlight is incident, it is possible to quickly inspect whether or not a discharge accident has occurred in a high-pressure guy tube, a transformer, or the like.

At this time, the PROM element with liquid crystal 56,
When an element using a liquid crystal that changes the light transmittance such as PDLC is used as 56 ′, the polarizer 27 and the analyzer 22 are used.
Is unnecessary. (Second Embodiment) FIG. 5 is a schematic diagram for explaining an image information recording apparatus and an image information reproducing apparatus according to a second embodiment of the present invention.

In this embodiment, the PROM element 16
Alternatively, the present embodiment is different from the first embodiment in that a DC voltage generator 26 capable of applying a DC bias voltage to the PROM elements 56 and 56 'with liquid crystal is further provided, but other configurations are the same as those in the first embodiment. is there.

By providing a DC voltage generator 26 in addition to the high-voltage AC voltage generator 15, not only the AC bias voltage but also the DC bias voltage can be applied to the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal. Can be. Therefore, not only the spark discharge that occurs periodically, but also the background high-pressure guy pipes 11a to 11c and the power line 10
a to 10c can also be recorded in a superimposed manner, and the location where the spark discharge has occurred can be accurately known.

In the present embodiment, first, the AC bias voltage is applied to the PROM element 16 by the high-voltage AC voltage generator 15.
Alternatively, a spark discharge pattern is recorded by applying to the PROM elements 56 and 56 'with liquid crystal, and then the DC bias voltage is applied by the DC voltage generator 26 to the PROM element 16 or the PRO with liquid crystal.
High-voltage guy tube 11a applied to M elements 56, 56 '
11c and the power lines 10a to 10c are superimposed on the PROM element 16 or the PROM elements 56, 5
6 'or a high-voltage AC voltage generator 15 and a DC voltage generator 26 simultaneously apply an AC bias voltage and a DC bias voltage to the PROM element 16 or the PROM elements 56 and 56' with liquid crystal. High-voltage guy tubes 11a to 11c and power lines 10a to
The image information of 10c may be simultaneously recorded in the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal. (Third Embodiment) FIG. 6 is a schematic diagram for explaining an image information recording apparatus and an image information reproducing apparatus according to a third embodiment of the present invention.

The image information of the blood vessel image as the living body transmission image is
A method of recording and reproducing by the image information recording device and the image information reproducing device of the present embodiment will be described.

The blood flow in the blood vessel fluctuates in a cycle corresponding to the heartbeat, and when taken as an X-ray image, a gray image corresponding to the amount of the blood flow is obtained. Therefore, the x-ray image of the blood vessel is an image whose intensity changes according to the heartbeat. On the other hand, when an image of a blood vessel is taken by an X-ray imaging apparatus, the image is taken together with a still image of a skeleton or the like, and only a blood vessel image cannot be taken clearly. In such a case, by using the image recording device and the image reproducing device according to the present invention, only a periodic blood vessel image can be clearly captured, which can contribute to diagnosis of various pathologies.

An X-ray is projected from an X-ray source 30 toward a human body 31 to be inspected, an X-ray transmission image is captured by an X-ray camera 32, and the captured X-ray image is displayed on a display device 33. The displayed image of the blood vessel is an image whose intensity is changed at the cycle of the heartbeat. The blood vessel image is projected onto the PROM element 16 or the PROM elements 56 and 56 'via the shutter 34, the imaging lens system 35 and the half mirror 36.

On the other hand, the pulse waveform of the human body 31 is measured by the pulse waveform measuring device 38, and the output signal is supplied to the phase adjuster 39. The phase adjuster 39 forms a pulse signal delayed by an appropriate time from the measured pulse, supplies this signal to the AC high-voltage power supply 40, and outputs the signal from the AC high-voltage power supply 40 to the output signal from the phase adjuster 39. A synchronized AC bias voltage is generated and applied to the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal.

With this configuration, even if a time delay occurs in the blood flow flowing in the blood vessel, the phase of the AC bias voltage to the PROM element 16 or the PROM elements 56 and 56 'with the liquid crystal and the blood flow at the observation position are not affected. Since the phases can be matched, only the blood vessel image can be clearly recorded in the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal.

The reproducing optical system for reproducing the image recorded in the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal is the same as in the first embodiment.

Also in the case of this embodiment, optical image processing such as optical Fourier transform can be performed on the recorded image as needed. (Fourth Embodiment) FIG. 7 is a schematic diagram for explaining an image information recording apparatus and an image information reproducing apparatus according to a fourth embodiment of the present invention.

A method of separately recording and reproducing a light such as a lighthouse or a signal flashing at a natural cycle from the street lights by the image information recording apparatus and the image information reproducing apparatus of the present embodiment will be described. The device as in this embodiment is called a navigation support device.

When an aircraft flies over the city or lands at an airport in the city, the light from the navigation support lighthouse or traffic light is separated from the city lights and detected. The information is used for flight control of aircraft.

The navigation support lighthouse 46 flashes at a predetermined natural frequency. The light from the lighthouse 46 passes through the shutter 17, the imaging lens system 18 and the half mirror 19, and the PROM element 16 or the PROM element 56
6 '. An AC bias voltage having the same frequency as that of the lighthouse 46 is PR by the high-voltage AC voltage generator 15.
It is applied to the OM element 16 or the PROM elements 56 and 56 'with liquid crystal. The phase of the AC bias voltage is adjusted by an output signal from a phase adjuster 44 provided before the high-voltage AC voltage generator 15.

Since an AC bias voltage having the same frequency as the blinking frequency of the lighthouse 46 is applied to the PROM element 16 or the PROM elements 56 and 56 'with liquid crystal, the light of the street 42 is not recorded and only the image of the lighthouse 46 is recorded. Is the PROM element 16
Alternatively, it is recorded in the PROM elements 56 and 56 'with liquid crystal.

The present invention is not limited to the embodiment described above, and various modifications and polarizations are possible. For example, in the above-described embodiment, a transmission type PROM element is used, but a reflection type PROM element formed with an aluminum reflection film may be used.

[0095]

Image information recording apparatus of the present invention exhibits, generates charges corresponding to light intensity of the writing light, and the image recording element for holding the generated electric charges as polarized charges, the image light from a subject Imaging means for causing the information recording element to enter as writing light, and an image of the subject formed by the writing light
Of the changes in the light intensity of the writing light for forming the required image.
And a AC bias voltage applying means for applying an alternating bias voltage having the same frequency and the wave number in the image information recording element, from an image of an object formed by the writing light
Since the necessary images are spatially separated and extracted , image information synchronized with the AC bias applied to the image information recording element can be selectively recorded.

Further, the image information reproducing apparatus of the present invention generates a charge corresponding to the light intensity of the writing light, holds the generated charge as a polarization charge, and reads the reading light in accordance with the held polarization charge. A spatial light modulator that modulates the light, an imager that causes light from the subject to enter the spatial light modulator as writing light, and an image pickup device that is formed by the writing light.
Change in light intensity of writing light that forms a required image among images
An alternating bias voltage application means for applying an alternating bias voltage having a frequency the same frequency to said spatial light modulator, and reading light projecting means for entering a read light to the spatial light modulator, from the spatial light modulator and a reading light detecting means for detecting the emitted are reading light, shape by the writing light
The necessary image is spatially separated from the image of the subject to be formed.
Since reading is performed at a distance, image information synchronized with the AC bias applied to the spatial light modulator can be selectively recorded and reproduced.

Further, there is provided a frequency detecting means for detecting a frequency of an intensity change of an image whose intensity changes at a constant frequency in an image of the object to be imaged, and an alternating current having the same frequency as the frequency detected by the frequency detecting means is provided. By applying the bias voltage to the image information recording element or the spatial light modulation element by the AC bias voltage applying means, the selective recording of the image information whose intensity changes at a constant frequency can be more effectively performed.

Further, by further providing a phase adjusting means capable of changing the phase of the AC bias voltage applied by the AC bias voltage applying means, image information whose intensity changes at a constant frequency, the AC bias voltage, Even if there is a phase difference φ between them, it is possible to effectively perform selective recording of image information whose intensity changes at a constant frequency.

Further, in addition to the AC bias voltage applying means, a DC bias voltage applying means capable of applying a DC bias voltage to the image information recording element or the spatial light modulation element is further provided, so that the intensity thereof can be maintained at a constant frequency. Can be superimposed and recorded in addition to the image information of which background changes. Therefore, the position of the image whose intensity changes at a constant frequency on the object to be imaged can be accurately known.

As the image information recording element and the spatial light modulation element, a charge corresponding to the light intensity of the writing light is generated by the photoconductive effect, and the generated charge is held as a polarization charge and held by the Pockels effect. When an element that changes the polarization state of the reading light in accordance with the polarization charge is used, the polarization state of the reading light can be changed by the element itself, and another reading material is provided in addition to the recording material. Eliminates the need.

Further, a charge corresponding to the light intensity of the writing light is generated by the photoconductive effect, the generated charge is held as a polarization charge, and the polarization of the reading light is changed according to the polarization charge held by the Pockels effect. By providing a liquid crystal in addition to the element for changing the state, the configurations of the image information recording device and the image information reproducing device can be simplified.

Further, the image information recording element or the spatial light modulation element may be made of a material having a photoconductive effect as a recording material,
With a structure including a liquid crystal as a material for reading, a material having a photoconductive effect but not a Pockels effect, such as a GaAs single crystal, a GaAs film, a hydrogenated amorphous silicon film, an amorphous silicon carbide film, An amorphous selenium film or the like can be used as a recording material for an image information recording element and a spatial light modulation element.

[Brief description of the drawings]

FIG. 1 is a sectional view for explaining a PROM element used in an image information recording device and an image information reproducing device of the present invention.

FIG. 2 is a cross-sectional view for explaining a PROM element with a liquid crystal used in the image information recording device and the image information reproducing device of the present invention.

FIG. 3 is a cross-sectional view for explaining another PROM device with a liquid crystal used in the image information recording device and the image information reproducing device of the present invention.

FIG. 4 is a schematic diagram for explaining an image information recording device and an image information reproducing device according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram for explaining an image information recording device and an image information reproducing device according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram for explaining an image information recording device and an image information reproducing device according to a third embodiment of the present invention.

FIG. 7 is a schematic diagram for explaining an image information recording device and an image information reproducing device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 7 ... Substrate glass 2, 6 ... Transparent electrode 3, 5 ... Insulating layer 4 ... Charge generation holding layer 10a-10c ... Power line 11a-11c ... High voltage guy tube 12 ... Current detector 13 ... Amplifier 14 ... Overtone generator DESCRIPTION OF SYMBOLS 15 ... High-voltage AC voltage generator 16 ... PROM element 17, 34 ... Shutter 18, 35 ... Imaging lens system 19, 36 ... Half mirror 20 ... Laser light source 21 ... Reproduction light shutter 22 ... Analyzer 23 ... TV camera 24 ... Monitor 25 Beam expander 26 DC voltage generator 27 Polarizer 30 X-ray source 31 Human body 32 X-ray camera 33 Display device 38 Pulse waveform measuring device 39, 44 Phase adjuster 40 AC high voltage Power supply 42 ... City 46 ... Lighthouse 50 ... Liquid crystal layer 51 ... Reflection layer 56,56 '... PROM device with liquid crystal

Continuation of the front page (56) References JP-A-1-50309 (JP, A) JP-A-2-282721 (JP, A) JP-A-3-200117 (JP, A) JP-A-3-113989 (JP) , A) JP-A-59-14841 (JP, A) JP-A-2-245721 (JP, A) 1989 IEICE Autumn National Convention Lecture Paper [Volume 4] Communication and Electronics (August 1989) 15th) P.S. 4-278 Applied Optics, Vol. 21 No. 20 PP. 3706-3712 (15 October 1982) (58) Field surveyed (Int. Cl. ⁶ , DB name) G02F 1/00-1/055 504 G02F 1/135 G02F 3/00-3/02 A61B 6/00 300 G01N 21/67 G01N 21/84 G01R 31/00-31/08

Claims (17)

(57) [Claims] An electric charge corresponding to the light intensity of the writing light;
An image information recording element for holding the generated charges as polarization charges, an imaging unit for causing light from a subject to enter the image information recording element as writing light, and the subject formed by the writing light Of the images
Same as the frequency of the light intensity change of the writing light to form the required image
AC bias voltage applying means for applying an AC bias voltage having one frequency to the image information recording element, wherein the AC bias voltage is applied to the image information recording element from the image of the subject formed by the writing light.
An image information recording apparatus for spatially separating and extracting various images . 2. An image information recording apparatus according to claim 1, further comprising a frequency detecting means for detecting a frequency of an intensity change of an image whose intensity changes at a constant frequency among the images of the object to be imaged. An image information recording device, wherein the AC bias voltage applying means applies an AC bias voltage having the same frequency as the frequency detected by the frequency detecting means to the image information recording element. 3. The image information recording apparatus according to claim 1, further comprising phase adjusting means for changing the phase of the AC bias voltage applied by said AC bias voltage applying means. Image information recording device. 4. The image information recording apparatus according to claim 1, further comprising a DC bias voltage applying means capable of applying a DC bias voltage to said image information recording element. Recording device. 5. The image information recording device according to claim 1, wherein the image information recording element generates a charge corresponding to the light intensity of the writing light, and uses the generated charge as a polarization charge. An image information recording device, comprising: a spatial light modulation element that holds and changes the polarization state of readout light in accordance with the held polarization charge. 6. An image information recording apparatus according to claim 5, wherein said image information recording element generates a charge corresponding to the light intensity of the writing light by a photoconductive effect, and holds the generated charge as a polarization charge. And an image information recording device which changes the polarization state of the reading light in accordance with the polarization charge held by the Pockels effect. 7. An image information recording apparatus according to claim 6, wherein a charge corresponding to the light intensity of the writing light is generated by said photoconductive effect, and the generated charge is held as polarization charge and held by a Pockels effect. An image information recording apparatus characterized in that a liquid crystal is further provided in addition to an element for changing the polarization state of the readout light in accordance with the polarization charge. 8. The image information recording device according to claim 1, wherein the image information recording element comprises a material having a photoconductive effect as a recording material and a liquid crystal as a material for reading. An image information recording device, comprising: 9. An electric charge corresponding to the light intensity of the writing light is generated,
The generated charge is retained as polarization charge, and a spatial light modulator that modulates read light in accordance with the retained polarization charge, and light from a subject enters the spatial light modulator as write light. Imaging means for emitting, of the image of the subject formed by the writing light,
Same as the frequency of the light intensity change of the writing light to form the required image
An alternating bias voltage application means for applying an alternating bias voltage having one of frequencies in the spatial light modulator, and reading light projecting means for entering a read light to the spatial light modulator, Ru emitted from the spatial light modulator Read light detecting means for detecting read light, wherein said necessary light is detected from an image of a subject formed by said write light.
An image information reproducing apparatus characterized by spatially separating and reading out various images . 10. The image information reproducing apparatus according to claim 9, further comprising a frequency detecting means for detecting a frequency of an intensity change of an image whose intensity changes at a constant frequency among the images of the object to be imaged. And an AC bias voltage applying means for applying an AC bias voltage having the same frequency as the frequency detected by the frequency detecting means to the spatial light modulator. 11. The image information reproducing apparatus according to claim 9, further comprising phase adjusting means for changing a phase of the AC bias voltage applied by said AC bias voltage applying means. Image information reproducing device. 12. The image information reproducing apparatus according to claim 9, further comprising a DC bias voltage applying means capable of applying a DC bias voltage to said spatial light modulator. Playback device. 13. The image information reproducing apparatus according to claim 9, wherein said spatial light modulator generates a charge corresponding to the light intensity of the writing light, and uses the generated charge as a polarization charge. An image information reproducing apparatus characterized by being a spatial light modulator that holds and changes the polarization state of readout light in accordance with the held polarization charge. 14. An image information reproducing apparatus according to claim 13, wherein said spatial light modulator generates a charge corresponding to the light intensity of the writing light by a photoconductive effect, and holds the generated charge as a polarization charge. In addition, an image information reproducing apparatus is an element that changes a polarization state of readout light according to polarization charges held by the Pockels effect. 15. An image information reproducing apparatus according to claim 14, wherein a charge corresponding to the light intensity of the writing light is generated by the photoconductive effect, and the generated charge is held as a polarization charge and held by the Pockels effect. An image information reproducing apparatus characterized in that a liquid crystal is further provided in addition to an element for changing the polarization state of the readout light in accordance with the polarization charge. 16. The image information reproducing apparatus according to claim 9, wherein said spatial light modulation element generates a charge corresponding to the light intensity of the writing light, and uses the generated charge as a polarization charge. An image information reproducing apparatus characterized by being a spatial light modulator that holds and changes the transmittance of readout light in accordance with the held polarization charge. 17. The image information reproducing apparatus according to claim 9, wherein said spatial light modulator comprises a material having a photoconductive effect as a recording material and a liquid crystal as a material for reading. An image information reproducing apparatus, comprising: