JPH0795181B2 - Optical associative device - Google Patents

Description

The present invention relates to an optical associative device used in the field of optical information processing.

[Problems to be Solved by Prior Art and Invention] Conventionally, a method shown in FIG. 2 has been proposed as a method for optically associating a perfect image from an incomplete image [Applied Physics; Volume 57, Vol. 10 (1988), pp. 1522-1527]. In this method, a complex hologram pattern of a reference image group is recorded in advance for each reference image by changing the irradiation angle of the reference light, and a wavefront conjugate with it is recorded. Make hologram 99 and hologram
The incomplete image A ′ is input to 98, and the light emitted from the hologram 98 is emitted in the direction of the reference light when the complete image A having a high correlation with the incomplete image A ′ is recorded. A complete image output A is obtained by irradiating the hologram 99 with the emitted light, and a feedback structure 93 for inputting the complete image by replacing the previous incomplete input.
By providing the non-linear process 94 and, only one associative output can be obtained.

However, this method requires a recording medium having a very high resolution as a memory for holographically recording a reference image, and currently, there is no practical one other than a photographic recording material that satisfies the demand. However, even if this was used, if there were not many reference images, one hologram could not be recorded completely, and it was necessary to mechanically switch the holograms when performing recording by dividing into several holograms and recording. . Therefore, with this method, it takes time to develop the hologram, and since the direction of the reference light is changed for each reference image, a very complicated hologram creation operation is required, and real-time processing is required. It was also impossible, and it took a lot of time to search when the amount of information to handle increased.

The present invention has been made to solve the above-mentioned problems, and a reference image memory can be easily formed without using a means such as holography, and a correlation between a reference image group and a test image can be obtained in real-time operation. It is an object of the present invention to provide an optical associative device that can dramatically increase the number of reference image groups by performing calculations and using a feedback system.

[Means for Solving the Problems] In order to solve the above-mentioned technical problems, the present invention outputs at least a coherent image based on an image to be inspected and a reference image group at the same time, and electrically or optically. A first image output means (for example, 1) capable of temporally and spatially modulating the output light complex amplitude, and an optical two-dimensional distribution pattern of the output light complex amplitude from the first image output means. First optical Fourier transform means (for example, 2) for performing a Fourier transform, and a spatial filter for limiting a light receiving range of output light from the first Fourier transform means to a spatial frequency range corresponding to the size of the image to be inspected. (For example, 3), and changing the coherent two-dimensional outgoing complex amplitude distribution in accordance with the spatial light intensity distribution pattern of the light output from the first optical Fourier transform means that has passed through the spatial filter. Second image output means (for example, 4) capable of performing optical Fourier transform of the two-dimensional distribution pattern of the output light complex amplitude from the second image output means, and the output thereof is the first image output. Second optical Fourier transform means (for example, 5) that is input to the means (for example, 1) as the modulated signal, and light detection means (for example, 6) that detects the optical output from the second optical Fourier transform means. It is an optical associative device composed of and.

[Operation] With the configuration of the optical associative device of the present invention as described above, the spatial patterns of the reference image group and the test image presented by the first image output means are the first optical Fourier transform means. Fourier transform is performed to form multiple interference fringes formed by the reference image group and the test image.

At this time, the light flux passes through the spatial filter,
Information of a fine portion which is not necessary for knowing the rough shape of the image disappears, and the second image output means outputs coherent light having a light intensity distribution or a phase distribution according to the light intensity distribution of the multiple interference fringes. A light flux is emitted.

The coherent light beam is optically Fourier-transformed by the second optical Fourier transforming means, and the two-dimensional light intensity distribution obtained as a result shows the positions of the test image and each reference image and their correlations. It will be an expression.

Here, the two-dimensional light intensity distribution is input to the first image output means, and the output light intensity of the first image output means corresponds to a large portion of the two-dimensional light intensity distribution. It is large in the image part and small in the opposite part.

While the above operation is repeated, the light intensity emitted from the reference image having a relatively low cross-correlation coefficient with respect to the test image is gradually reduced, leaving a reference image group close in shape to the test image. Therefore, the number of reference images to be compared is reduced. And as a result of fewer reference images to compare,
The visibility of the interference fringes obtained by the first Fourier transform means rises, and an accurate comparison can be made on the remaining images. However, when the image to be inspected is an incomplete image in which a part of the reference image is missing, it shows a high cross-correlation coefficient when the light intensity emitted from the reference image is to some extent small, so the initial cross-correlation Even if the statistical coefficient is not large, the light intensity emitted from the reference image gradually increases as the above trial is repeated, and finally shows a large cross-correlation coefficient. , It won't be truncated in the early stages.

Then, by repeating this process, only the one having the highest cross-correlation coefficient remains, which is associated-recognized as the test image.

The optical discriminating apparatus of the present invention outputs at least a coherent image of a test image and a reference image group at the same time, and can electrically or optically modulate the output optical complex amplitude in time and space. An image output unit (for example, 1); a first optical Fourier transform unit (for example, 2) for optically Fourier transforming a two-dimensional distribution pattern of the output light complex amplitude from the first image output unit; A spatial filter (for example, 3) that limits the light receiving range of the output light from the first optical Fourier transforming device to a spatial frequency range according to the size of the image to be inspected, and the first filter that has passed through the spatial filter. Second image output means (for example, 4) capable of changing the coherent two-dimensional output complex amplitude distribution according to the spatial light intensity distribution pattern of the light output from the optical Fourier transforming means, The second optical signal which is obtained by optically Fourier transforming the two-dimensional distribution pattern of the output light complex amplitude from the second image output means and inputs the output to the first image output means as its modulation signal. Fourier transform means (for example 5), and light detection means (for example 6) for detecting the light output from the second optical Fourier transform means, wherein the test image is an incomplete image of the reference image. When the cross-correlation coefficient is obtained as a light flux range corresponding only to a low frequency region where the outlines of images to be compared with the light flux limitation range by the air filter can be obtained, a rough association is performed. It is something that is sought after.

At this time, by changing the output light intensity from each reference image in the first image output means in a positive feedback manner by the output of the second Fourier transform means according to the cross-correlation coefficient, The effect from an image with a low correlation coefficient is selectively eliminated, and accurate association can be performed.

Further, when the test image is an image in which a part of the reference image is missing, a relatively large cross-correlation output is produced even if the output from the first image output means by the corresponding reference image is low. Therefore, more accurate association can be performed by the positive feedback output light intensity change in the first image output means.

Next, the optical associative device of the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

[Embodiment] FIG. 1 is a schematic configuration diagram showing a configuration of an example of an optical associative device according to the present invention.

In the optical layout diagram of FIG. 1, the optical associative device comprises an image output means 1, an optical Fourier transform means 2, a spatial filter 3, an image output means 4, an optical Fourier transform means 5, and a light detection means 6. The configuration will be described in detail below. A light beam 12 emitted from a coherent light source 11 such as a semiconductor laser or a gas laser is a beam expander 13
Then, it is converted into an appropriate beam diameter, and with the beam splitter 14,
It is divided into two optical paths.

The light flux 12 that has passed through the beam splitter 14 passes through a liquid crystal light valve (hereinafter referred to as LCLV) 15 and the image display device.
Incident on 16. Here, the LCLV15 is a spatial light modulator that can spatially modulate the transmittance distribution by inputting an electrical signal, and the most common example is a liquid crystal panel used for a liquid crystal television or a computer display. Is used. The LCLV15 is initially set to have a uniform transmittance, but as a result of the subsequent steps, the shape has a high transmittance at the portion corresponding to the reference image, which has a high correlation with the test image. The transmittance of the non-exposed area becomes low.

Further, as shown in FIG. 3, the image display device 16 is divided into a test image display portion 16b and a reference image display portion 16a, and the reference image display portion 16a records a plurality of reference images on a photographic film. Is a spatial light modulator capable of displaying a plurality of reference images or a plurality of reference images by electrical input or optical input, and the test image display portion 16b is a space where electrical or optical input of the test image is possible. It is an optical modulator. That is, as shown in the figure, the reference image group, for example, a, b,
c, d, and e are displayed in the 16a portion, and the test image s is displayed in the 16b portion.

Now, the light flux 12 that has passed through the image display device 16 passes through the Fourier transform lens 21 and enters the screen 41 placed on the Fourier transform surface thereof. On this screen 41, the light intensity proportional to the square of the two-dimensional Fourier transform of the complex amplitude distribution in the image display device 16 is observed. This light intensity distribution is detected by a two-dimensional photoelectric conversion element 42 such as a CCD. At that time, the visual field of the spatial filter 3 or the two-dimensional photoelectric conversion element 42 is limited so that the general shape of the image can be known. The information of unnecessary fine parts in is cut.

Here, the image obtained by the two-dimensional photoelectric conversion element 42 passes through the video amplifier and the liquid crystal drive circuit 43 as an electric signal,
Displayed on the LCLV45. Like the LCLV15, this LCLV45 also forms a spatial light modulator, which modulates the complex amplitude of incident light and emits it. The light flux 47 incident on the LCLV 45 is the light flux 12 emitted from the laser 11 divided by the beam splitter 14. Therefore, the light source of the image output means 4 and the light source of the image output means 1 are shared here. Will be.

The light flux 47 emitted from the LCLV 45 passes through the Fourier transform lens 51 and enters the screen 52. At this time, screen 52
Is the position of the Fourier transform with respect to LCLV45. Therefore, the light intensity on the screen 52 represents the degree of spatial cross-correlation and spatial autocorrelation between the reference image group and the test image. Becomes Therefore, if the images are arranged on the image display device so that the cross-correlation between the reference images does not overlap the cross-correlation position between the reference image and the test image, the two-dimensional photoelectric conversion element 61 of the CCD can be used. The position of the reference image having a strong correlation with the test image and the degree of the correlation can be detected.

Now, what the peak of the light intensity according to the degree of cross-correlation is like will be described below by taking the pattern shown in FIG. 3 as an example.

On the image display device 16, as shown in FIG.
Reference image groups a, b, c, d, e and a test image s are drawn.

In the test image shown in FIG. 3, it is considered that one of the reference images is partly missing. For example, as shown in FIG. 4, the reference image is represented by a straight line of length 2a. , It is assumed that the image to be inspected is a straight line of length a.

The spatial coordinates indicating the position of the inspection image S are tentatively (0) in one dimension.
Let this be denoted as S (0).

Similarly, the reference image group, expressed as a (a _x). Irradiating these patterns with coherent light, the Fourier transform lens 21
Then, when the Fourier transform is performed, the light intensity pattern I (f _x ) on the screen 41 is as follows.

I (f _x ) = | S + A · exp (j2πf _x a _x ) | ² = | S | ² + | A | ² + S ^* · A · exp (j2πf _x a _x ) + c.c ....
(1) where f _x is the spatial frequency in the x direction on the screen 41, S and A are the complex amplitudes of the Fourier transform of the optical amplitude distributions of the test image and the reference image, and the ^* mark on the shoulder ^. Represents the complex conjugate amount of the light amplitude distribution of each image.

Here, S and A are, respectively, S = {sin (π · a · f _x ) / π · a · f _x } · a A = {sin (2π · af _x ) / 2π · af _x } · 2a Is represented.

Now, I (f _x ) = (| S | ² + | A | ² ) {1 + mcos (2πaf
_x )}, so the visibility of the interference fringes on the screen 41 m
Is Becomes Therefore, in the low frequency region, f _x → 0 and m
= 4/5.

Here, if the reference image is shielded by a mask having a transmittance of K, similarly, the visibility of the interference fringes becomes Becomes Therefore, the maximum value of the visibility m ′ is m ′ = 1 when K = sin (π · af _x ) / sin (2πaf _x ). Therefore, in the low frequency region,
When f _x → 0 and K = 1/2, the contrast of the interference fringe becomes maximum.

By the way, when the above light intensity pattern I (f _x ) is written in the LCLV45 as a transmittance distribution and is again Fourier transformed by the Fourier transform optical system, the light intensity pattern I (x) on the screen 52 is I (x) = ∫ _{I (f x) · exp (} -j2πf x x) df x = s * s + a * a + s * a {δ (a x -x) + (a x +
x)} (2).

Here, * represents the correlation.

In this way, the autocorrelation of each image appears on the optical axis, and the cross-correlation between the test image and the reference image group is relative to the optical axis.
One pair appears symmetrically at a position from the optical axis corresponding to the relative position between the test image and the reference image group.

Therefore, a peak corresponding to the degree of cross-correlation between the test image and the reference image group appears at the position on the screen 52 corresponding to the position of the reference image group on the image display device 16.

Now, s * a is related to the visibility of the interference fringes on the Fourier transform surface, and the light quantity corresponding to m / 4 of the total light quantity is the cross-correlation quantity. Therefore, as shown in FIG. 4, when a part of the reference image is missing, if the Fourier transform image of the low frequency region of the spatial frequency is taken, the masked one (K = 1/2)
However, the amount of cross-correlation becomes relatively large. The above phenomenon always occurs when a part of the image to be inspected is occluded, and the other part of the image to be inspected is combined with a part of the reference image. Even in such a case, the visibility becomes larger as a whole when the reference image is shielded.

By the way, if the number of reference images is large as it is, it becomes impossible to clearly read the correlation peak of the reference image group with respect to the test image.

The reason is that the correlation term shown in the equation (2) is related to the formation of interference fringes due to the overlapping of the Fourier transform patterns of the images in the equation (1). When the visibility of the interference fringes decreases, the light intensity of the correlation peak decreases as a result, and when the fineness of the light intensity distribution of the formed interference fringes and the dynamic range exceed the capability of the spatial light modulator. , The output of the correct correlation peak cannot be obtained.

Therefore, in this embodiment, the light intensity on the screen 52 is read by the two-dimensional photoelectric conversion element 61, sent to the image processing and liquid crystal drive circuit 62 as an electric signal, and the cross-correlation amount with each reference image is standardized. By determining the transmittance distribution of LCLV15 according to the amount, the amount of light with which each reference image is irradiated is changed. That is, for example, if the reference image having the highest degree of correlation with the test image is b, the transmittance of the pixel portion of the LCLV 15 through which the light flux illuminating b is transmitted is maximized. In other reference images, for example, the reference image a
In contrast, the transmittance of the image portion through which the light flux illuminating the reference image a of the LCLV15 is transmitted is determined so that the light intensity illuminating a is equal to the light intensity s * a / s * b. . Hereinafter, the same applies to other reference images.

In this way, the above operation can be repeated by using the pattern after changing the transmittance of the LCLV15 and changing the light amount applied to each reference image as an input.

FIG. 5 shows the relationship between the number of trials and the output on the screen 52 when the test image s has a pattern in which a part of the reference image c is missing in the image group shown in FIG. As described above, the reference images a, e, and d having a small correlation peak output other than the reference image c to be associated with each other have a small irradiation light amount once, while the reference image c to be associated with As described above, the visibility of the interference fringes on the screen 41 increases and the cross-correlation peak output increases. At this time,
For the reference image b that should initially not have a strong cross-correlation peak, the cross-correlation peak loses its light quantity after several trials due to the imbalance of the light quantity ratio, and In the case of a reference image that should not be associated with the reference image, the light amount of the cross-correlation peak monotonously decreases because there is no peak of the visibility of the interference fringes with the image to be inspected in the place where the light amount irradiated is small. Therefore, as a result, the test image c that should be associated is recalled.

In addition, when there are some reference images with a high degree of correlation with the image to be inspected, a threshold level is set for the degree of correlation for some reference images with a significantly low degree of correlation, and the space is set at a stage where the number of trials is small. It is also possible to minimize the transmittance of the modulator. At this time, the reference image whose degree of correlation becomes lower than the threshold value after several trials can similarly lead the result quickly if the transmittance of the spatial light modulator is also set to the minimum.

Furthermore, since the number of reference images is limited at the initial stage, the number of objects to be compared is reduced in the subsequent operations, the visibility of interference fringes is increased, and correct recognition is performed.

Further, although not to be associated with the reference image, when there is one having a high cross-correlation value with respect to the test image, the light amount of the cross-correlation peak due to the reference image to be associated is
Initially, it is relatively small and goes through a process of becoming larger during repeated trials, but this correlation peak light intensity exceeds the correlation peak light intensity by the reference image that initially had the largest correlation peak, or both peaks. When the fluctuation of the light quantity becomes small, the irradiation light quantity for the reference image whose correlation peak light quantity was initially small is set to the maximum irradiation light quantity, and if the irradiation light quantities for the other reference images are made smaller than that, the association will quickly converge. Become.

Further, when the number of trials becomes large, it is possible to ambiguously judge the correlation degree of the test image with respect to the reference image by comparing the correlation degrees at the time when the cross correlation degree does not change as a whole. Become.

Also in the above-mentioned embodiment, what is the transmittance to be changed if the rule is set so that it is high for the reference image having the highest correlation degree and is low for the other reference images? Needless to say, even if it is. For example, when the reference image having the highest degree of correlation is b, the light intensity irradiating another reference image a is defined as f (s * a) / f (s * b) with respect to the monotonically increasing function f (x). Is also possible.

Next, FIG. 6 is a schematic diagram showing the configuration of another optical associative device of the present invention. The invention will now be further described.

In the optical associative device shown in FIG. 6, the light beam 12 emitted from the laser 11 passes through the beam expander 13 and enters the polarization beam splitter 14 '. In the polarization beam splitter 14 ', only the s-polarized component is reflected, and the p-polarized component is transmitted to become a light beam 47.

Then, the light flux 12 composed of the s-polarized component enters the LCLV 15 '. Here, LCLV15 'is a reflective liquid crystal light valve as shown in FIG. In this liquid crystal light valve, a photoconductive layer 77 and a dielectric mirror 75 are arranged between a liquid crystal panel sandwiched by transparent electrodes 72 and 78, and the photoconductive layer 77 is divided into required pixel sizes. Has been done. In this LCLV 15 ′, the size of this pixel is the size of the reference image in the image display device 16.

Here, the dielectric mirror 75 is arranged on the liquid crystal layer side (right side in the figure) with respect to the photoconductive layer 77, and this is the incident direction of the reading light. At this time, the transparent electrodes on both sides (ie 72 and 78)
When a writing light is irradiated with a voltage applied between the two), a voltage drop occurs in the photoconductive layer 77 in each divided pixel 70a in accordance with the amount of the writing light, and the voltage applied to the liquid crystal in each portion is increased. The plane of polarization of the read light that has changed and entered is rotated. Therefore, the light flux 12 has its polarization plane rotated in response to the writing light A incident on the LCLV 15 ', and the reflected light thereof passes through the polarization beam splitter 14' in accordance with the intensity distribution of the writing light. However, at the beginning of the process, the polarization beam splitter 1 produces a uniform light amount over the entire luminous flux range by setting the bias potential or entering the bias light.
It is designed to pass through 4 '. The structure of the reflection type liquid crystal light valve of 15 is as shown in FIG. That is, a glass substrate 71, a transparent electrode 72, a liquid crystal 74, a dielectric mirror 75, a photoconductive layer 77, a transparent electrode 78, and a glass substrate 76 are laminated in this order and are divided into divided pixels 70a. .

Now, the light flux 12 that has passed through the polarization beam splitter 14 'is
The light enters the image display device 16, further passes through the mirror 22, the Fourier transform lens 21, and irradiates the LCLV 45 ′ with the intensity pattern by the Fourier transform of the complex amplitude on the image display device 16. The LCLV 45 'is basically the same as the LCLV 15', except that the above-mentioned light flux 12 is used as the writing light A and the size of the divided pixels is reduced according to the pattern of the interference fringes incident thereon.

The readout light for this LCLV 45 'is the light beam 47 that has passed through the polarization beam splitter 14'. The light beam 47 passes through the half-wave plate 46, rotates its polarization direction by 90 degrees, and enters the polarization beam splitter 48. At this time, since the polarization state of the light beam 47 is s-polarized with respect to the polarization beam splitter 48, almost all of the light beam 47 is reflected,
It is incident on the LCLV45 'and becomes the readout light. The luminous flux 47 incident on the LCLV 45 ′ is similarly modulated with the luminous flux 12 on the LCLV 15 ′, and the Fourier transform lens 51 forms a pattern corresponding to the Fourier transform of the intensity distribution of the luminous flux 12 incident on the LCLV 45 ′ on the screen 52 and It is incident on LCLV15 '. However, the light beam 47 incident on the LCLV 15 ′ has an optical axis, that is, a 0th-order light spot position, by the half mirror 54 or the like.
It is set so as to come to the position 55 of the upper image to be inspected. At this time, the position of the reference image and the arrangement of the optical system are set in advance so that the light spots of the cross-correlation peaks corresponding to them respectively come to the positions of the reference image on the LCLV 15 ′.

Therefore, thereafter, with respect to the test image, the reference image having a strong correlation intensity is illuminated with the light flux having a stronger intensity, and the reference image having a weaker correlation intensity is illuminated with the light flux having a weaker intensity. The cross-correlation intensity output is obtained by detecting the light intensity distribution on the screen 52 with a two-dimensional photoelectric conversion element 61 such as a CCD.

In the present invention, although there are differences in specifications with respect to the portion functioning as the spatial light modulator, in principle, the same electrical address type and optical address type can be used. is there. As an example of the electric address type, in addition to the above-mentioned liquid crystal panel, a ceramic or crystal exhibiting an electro-optical effect such as PLZT, KDP, BSO (Bi ₁₂ SiO ₂₀ ) or the like to which a matrix electrode is added is often used. .

Also in the photo-addressable type, a material similar to the electrically-addressed type is generally combined with a photoconductive layer as described in FIG. However, in a crystal having a photovoltaic effect such as BSO or BaTiO _3, there is no need to add a photoconductive layer because the photoinduced refractive index change occurs due to spontaneous polarization depending on the incident light intensity. It should be noted that these spatial modulators can be configured as a transmissive type or a reflective type. However,
In the case of an optical address type in which the reading light completely erases the information of the writing light, the wavelength range of the reading light and the writing light is separated so that the reading light does not affect the writing information. Ingenuity is needed.

Further, when the electric address type is used, a two-dimensional photoelectric conversion element and its drive circuit for obtaining the input image are required, but there is an advantage that the signal can be easily processed.

Incidentally, the commonly used incoherent-coherent conversion element belongs to the reflective spatial light modulator of the above-mentioned optical address, and in order to use it for the image display portion 16b of the image display device 16, the An imaging optical system for irradiating the incoherent-coherent conversion element with an input image is required. In that case, if the reference image display portion 16a is also of the reflective type regardless of the optical address and the electrical address, it is easy to configure an optical system. A configuration diagram of an example of such an optical system is shown in FIG.

In the optical associative device of FIG. 8, the luminous flux from the laser 11
The image display device 1 is reflected by the beam splitter 14.
It is incident on 6 '. Here, the image display device 16 'is composed of an incoherent-coherent conversion element corresponding to the image display portion to be inspected and a reflective electrical address type spatial light modulator such as LCLV corresponding to the reference image display portion. Here, the incoherent-coherent conversion element receives an optical modulation input from the side opposite to the light beam 12. This modulation input is, for example, as shown in the figure, the image 18 of the object s to be inspected, which is imaged by 16b on the screen of the incoherent / coherent element by the imaging lens 17. Further, the input of the reference image display portion, the reference image group, the feedback information based on the cross-correlation degree detected by the two-dimensional photoelectric conversion element 61, that is, should be emitted from the image display device 16 'of each reference image. The information on the light intensity is superimposed. That is,
In the optical associative device of FIG. 8, the image display device 16 'simultaneously serves the functions of the LCLV 15 and the image display device 16 of the optical associative device of FIG.

Regarding the other parts, although the spatial light modulator used is of the electrical address type or the optical address type, or the combination of the transmission type or the reflection type, there is a difference. And the description of the optical associative device of FIG. 6 is almost the same, and the explanation numbers are represented by the corresponding ones.

As can be seen from the above description, these spatial light modulators can be in any combination, and therefore the optical associative device of the present invention can take a number of embodiments depending on the combination. You will be able to

[Advantages of the Invention] The optical associative device according to the present invention achieves the above-mentioned effects. In summary, the following remarkable technical effects are obtained.

Optical association that can dramatically increase the number of reference image groups by performing correlation calculation between the reference image group and the test image in real time without using holography or other means and forming a feedback system The equipment could be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing the configuration of an example of the optical associative device of the present invention. FIG. 2 is a schematic diagram showing a conventional optical associative device. FIG. 3 is a schematic conceptual view showing an image display device in an example of the optical associative device of the present invention. FIG. 4 is an explanatory diagram showing an example of a reference image and one input test image in the optical associative device of the present invention. FIG. 5 is a graph showing the relationship between the number of trials carried out and the output of the light detection means 6 in the optical associative device of the present invention. FIG. 6 is a schematic configuration diagram showing the configuration of another example of the optical associative device of the present invention. FIG. 7 is a schematic cross-sectional view illustrating the configuration of a reflective liquid crystal light valve used in the optical associative device of the present invention. FIG. 8 is a schematic configuration diagram showing the configuration of another example of the optical associative device of the present invention. [Description of Signs of Main Parts] 1, 4 ... Image output means 2, 5 ... Optical Fourier transform means 3 ... Spatial filter 5 ... Optical Fourier transform means 6 ... Photodetection means 11 ... Laser 12 , 47 ...... Luminous flux 14 ...... Beam expander 14 ', 48 ...... Polarizing beam splitter 15, 15', 16 ', 45, 45' ...... Liquid crystal light valve 16 ...... Image display device 16a ...... Reference image display section 16b …… Inspected image display section 17 …… Imaging lens 18 …… Inspected object 21,51 …… Fourier transform lens 41,52 …… Screen 42,61 …… Two-dimensional photoelectric conversion element 43 …… Video amplifier and Liquid crystal drive circuit 46 …… Half wave plate 50 …… Deflecting beam splitter 44, 53 …… Mirror 54 …… Half mirror 62 …… Image processing and liquid crystal drive circuit 70 …… Reflective liquid crystal valve 70a …… Fractionation Pixels 71, 76 ... Glass substrates 72, 78 ... Transparent electrodes 73 ... Spacers 74 ... Crystal layer 75 ...... dielectric mirror 77 ...... photoconductive layer 79 ...... AR coating 80 ...... reference image memory

Claims (9)

[Claims] 1. A first image output means for outputting at least a coherent image of a test image and a reference image group at the same time, and capable of electrically or optically modulating the output light complex amplitude in time and space. A first optical Fourier transform means for optically Fourier transforming a two-dimensional distribution pattern of complex amplitude of output light from the first image output means, and output light from the first Fourier transform means. A spatial filter that limits a light receiving range to a spatial frequency range according to the size of the image to be inspected; and a spatial light intensity distribution pattern of the optical output from the first optical Fourier transforming unit that has passed through the spatial filter. A second image output unit capable of changing the coherent two-dimensional output light complex amplitude distribution; and a two-dimensional distribution pattern of the output light complex amplitude from the second image output unit. A second optical Fourier transform means for optically Fourier transforming the output and inputting the output to the first image output means as its modulation signal, and a light output from the second optical Fourier transform means are detected. An optical associative device, which essentially comprises: 2. The first image output means at least,
A coherent light source, a first spatial light modulator capable of modulating the spatial distribution pattern of the complex amplitude of the light flux from the light source, and a reference image having the light flux emitted from the first spatial light modulator as input The optical associative device according to claim 1, comprising one or a plurality of display bodies for displaying a group and an image to be inspected. 3. The first spatial light modulator is divided into sections corresponding to each reference image forming a reference image group, and each section is an output light from the second optical Fourier transform means. 3. The optical associative device according to claim 2, wherein a portion corresponding to each of the two is received, and its transmittance or reflectance changes according to the amount of light. 4. The output from the second optical Fourier transform means is received by the first two-dimensional photoelectric conversion element,
The optical associative device according to claim 2, wherein the first spatial light modulator is electrically modulated according to an output signal from the first two-dimensional photoelectric conversion element. 5. The optical association according to claim 2 or 3, wherein the display body for displaying the reference image group is a second spatial light modulator capable of electrical modulation. apparatus. 6. The optical associative device according to claim 2, wherein the display for displaying the test image is an incoherent-coherent conversion element. 7. The first image output means at least,
The optical associative device according to claim 1, wherein the third spatial light modulator is a coherent light source and a third spatial light modulator capable of performing modulation by an electric input for displaying a reference image group and a test image. 8. The second image output means at least,
A coherent light source, and second two-dimensional photoelectric conversion means for receiving the output light from the first Fourier transform means,
7. A fourth spatial light modulator, which essentially modulates and outputs a complex amplitude distribution of an incident light beam based on a signal from the second two-dimensional photoelectric conversion means. An optical associative device according to any one of items 1 to 7. 9. The second image output means includes at least:
From a coherent light source and a fifth spatial light modulator whose optical characteristics change two-dimensionally or three-dimensionally depending on the intensity distribution of the incident light output from the first Fourier transforming means. Claim 1 characterized by being essentially
An optical associative device according to any one of items 1 to 7.