JP2889659B2 - Optical function element - Google Patents

Description

The present invention relates to an optical functional device.

2. Description of the Related Art It is extremely important in image information processing to input an image pattern and extract its edge or centroid.

The inventor has previously proposed an optical functional device as shown in FIG. 4 (A) as an optical functional device capable of extracting an edge and a center of gravity.

In the drawing, reference numeral 3 denotes a transfer layer in which microelements in which bacteriorhodopsin is oriented are arranged. The arrangement of the elements in the transfer layer 3 may be one-dimensional or two-dimensional, but here, for simplicity of description, it is assumed that the elements are arranged one-dimensionally in the horizontal direction in the drawing.

A transparent hydrogen ion supply layer 1 is provided on one side of the transfer layer 3, and a diffusion layer 5 is provided on the other side.

The detection layer 7 is sandwiched between the transfer layer 3 and the diffusion layer 5.
Is provided. The detection layer 7 is formed by arranging minute pH electrodes corresponding to the arrangement of the elements in the transfer layer 3. The bacteriorhodopsin is oriented so that each element in the transfer layer 3 transfers hydrogen ions of the hydrogen ion supply layer 1 to the diffusion layer 5 side when irradiated with light. 4 (B) and below, the horizontal axis X is the same as FIG. 4 (A).
In the horizontal direction.

FIG. 4 (B) shows the transfer layer 3 via the hydrogen ion supply layer 1.
When a light pattern having a one-dimensional spatial intensity distribution as described above is input, the irradiated bacteriorhodopsin alignment element transfers hydrogen ions from the hydrogen ion supply layer 1 to the diffusion layer 5. The amount of hydrogen ions transferred from each element is proportional to the intensity of light applied to the element.

Hydrogen ions transferred to the diffusion layer 5 by one element diffuse into the diffusion layer 5 with a Gaussian function type concentration distribution. The diffusion of all the transferred hydrogen ions is obtained by superimposing such a Gaussian function type diffusion for each element. In the example being described, the distribution of the hydrogen ion concentration ρ in the diffusion layer 5 in the X direction is the same as that of the first embodiment. 4. As shown in FIG. 4 (C), the whole becomes a Gaussian function.

The distribution of the concentration ρ is detected by the detection layer 7 and the result is expressed as X
Is differentiated twice to obtain a curve as shown in FIG. 4 (D). Since the zero-cross point of this curve corresponds to the edge of the input light pattern as shown in the figure, the edge can be detected by obtaining the zero-cross point.

Further, since the hydrogen ion concentration detected by the detection layer 7 changes with time so as to keep its Gaussian function type and its half-value width increases, it is possible to extract the center of gravity by utilizing this fact.

[Problem to be Solved by the Invention] Since the above-mentioned optical functional element uses a biological material called bacteriorhodopsin, mass productivity is not always good. Also, when mass-produced, it is difficult to achieve uniform performance of individual optical functional elements.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide an optical functional element that can perform edge extraction and gravity center extraction without using a biomaterial.

[Means for Solving the Problems] Hereinafter, the present invention will be described.

The optical functional device according to the first aspect has a light receiving unit, a diffusion unit, a light receiving layer, and a signal processing unit.

The "light receiving means" receives a one-dimensionally or two-dimensionally incident light pattern and reproduces the light pattern with light. No biological material such as bacteriorhodopsin is used for the construction of the light receiving means.

The “diffusion unit” optically diffuses the light pattern reproduced by the light receiving unit into an optical signal.

The “light-receiving layer” is formed by arranging light-receiving elements one-dimensionally or two-dimensionally, and is arranged at a predetermined distance from the diffusion means to photoelectrically convert the optical signal.

The "signal processing means" performs a spatial differentiation process on the output of the light receiving layer.

The optical functional element of the second aspect has a displacement means in addition to the configuration of the optical functional element of the first aspect.

"Displacement means" changes the distance between the diffusion means and the light receiving layer.

The optical function device according to the first aspect can perform feature extraction such as centroid extraction or edge extraction.

The optical function device according to claim 2 can perform the feature extraction and the edge extraction.

The light receiving means and the diffusing means do not necessarily need to be separate bodies. For example, the light receiving means and the diffusing means can be used with the diffusion plate itself.

[Operation] In FIG. 3 (A), reference numeral 16 denotes a diffusion plate.
The diffusion plate 16 is, for example, ground glass.

Considering the case where this diffusion plate 16 is irradiated with a light pattern having a δ-function light intensity as shown in FIG. 3 (A), this light pattern is light concentrated at one point. As a result, diffused light DL centering on the light concentration position is generated.

This diffused light DL is parallel to the diffuser plate 16 and d ₁ , d ₂
When the light intensity is measured on planes separated by distances (> d ₁ ) and d ₃ (> d ₂ ), the light intensity distributions as shown in FIGS. 3 (B), (C) and (D) are obtained, respectively. Can be done.

Each of these intensity distributions can be approximately regarded as a Gaussian function. The inventions of claims 1 and 2 make use of this.

The light intensity distribution which can be regarded as the approximate Gaussian function changes so that the half-width of the Gaussian function increases as the distance between the surface for measuring the light intensity distribution and the diffusion plate 16 increases. That is, in the substance diffusion, when the concentration distribution of the diffusing substance is a Gaussian function, the Gaussian function representing the concentration distribution changes so that the half-width increases with time.
In the intensity distribution of the light diffused at 16, the distance from the diffuser 16 of the surface on which the intensity distribution is measured corresponds to the time in the density distribution.

 The invention of claim 2 makes use of this fact.

[Example] Hereinafter, a description will be given according to a specific example.

FIG. 1A schematically shows an embodiment of the first aspect of the present invention.

Reference numeral 10 denotes a light receiving element array in which light receiving elements are arranged in one row, and reference numeral 14 denotes a light emitting element array in which light emitting elements are arranged in one row. The arrangement of the light receiving elements and the light emitting elements in these arrays 10 and 14 correspond to each other.

Reference numeral 12 indicates a control circuit. The control circuit 12 receives the output of the light receiving element array 10 and responds to the input to the light emitting element array.
Make 14 emit light. That is, the light emitting element array 14 reproduces the one-dimensional light pattern received by the light receiving element array 10.

Therefore, the light receiving element array 10, the light emitting element array 14, and the control circuit 12 constitute light receiving means.

A diffusion plate 16 as a diffusion means is provided on a light emitting surface of the light emitting element array 14, and converts a light pattern reproduced on the light emitting element array 14 into an optical signal based on diffused light DL.

A light receiving layer 18 is provided at a position separated from the diffusion plate 16 by a predetermined distance in parallel with the diffusion plate 16.

The light receiving layer 18 is formed by arranging light receiving elements in one row in the left-right direction in the drawing, corresponding to the arrangement of the light emitting elements in the light emitting element array 14.

The output of the light receiving layer 18 is input to an arithmetic circuit 20 as signal processing means.

In FIG. 1A, the X axis is set on the light emitting surface of the light emitting element array 14 in the horizontal direction of the figure, and the x axis is set on the light receiving surface of the light receiving layer 18 in the horizontal direction of the figure. .

Now, when one light emitting element located at the coordinate X ₀ on the X axis emits light, the output of the light receiving layer 18 is represented by W (x,
X ₀ ). Assuming that x coordinate corresponding to coordinate X ₀ is x ₀ , W
(X, X ₀ ) is a function similar to a Gaussian function having a peak at coordinate x ₀ .

Then, assuming that a light pattern having an intensity distribution on the light receiving element array 10 of the light receiving means is irradiated, and this light pattern is reproduced on the light emitting element array 14 as a light pattern having an intensity distribution f (X), At this time, the output from the light receiving layer 18 is D = ∫W (x, X ₀ ) f (X ₀ ) dX ₀ .

When this output is differentiated twice by X, d ² D / dx ² = ∫ (d ² W (x, X ₀ ) / dx ² ) f (X ₀ ) dX ₀ is obtained. As described above, W (x, X ₀ ) is similar to a Gaussian function, and X ₀ , x is included in this function in the form of (x−X ₀ ). be able to.

When ^{-∫ (d 2 W (x,} X) / dX 2) f (X) dX W (x, X) is given that can be approximated by a Gaussian function, this expression is the input of the optical pattern f (X) ▽ ² It is the same as applying the G operator.

Therefore, the edge of the input pattern can be detected as the zero-cross point of the calculation result.

That is, the edge detection performed by this apparatus is equivalent to the edge extraction by the ▽ ² G operator proposed by Marl-Hildress.

As a specific example, when an optical pattern as shown in FIG. 1 (B) is input, an output D as shown in FIG. 1 (C) is obtained from the light receiving layer 18, and this is differentiated twice in space. Then, the result becomes as shown in FIG. 9D, and the edge of the input pattern can be detected as the zero cross point.

Note that the distance between the diffusion plate 16 and the light receiving layer 18 is set to a “predetermined distance” so that the above-described edge extraction is appropriately performed.

FIG. 2A schematically shows an embodiment of the second aspect of the present invention. In order to avoid complication, the same reference numerals as those in FIG. 1 are used for those which do not seem to be confused.
The difference from the embodiment of FIG. 1 is that in the embodiment of FIG. 2A, a displacement means 17 is provided, and the light-receiving layer 18 can be displaced in the vertical direction in the figure.

It will be easily understood that the edge can be extracted in this embodiment in the same manner as in the embodiment of FIG.

In this embodiment, in addition to the edge extraction, it is possible to extract features such as the center of gravity. A description will be given of the case of extracting the center of gravity as an example.

Now, it is assumed that the input light pattern is as shown in FIG. 2 (B). The center point between the two pulse-like input points is the center of gravity.

In the case of such an input pattern, the diffusion plate 16 and the light receiving layer 18
If the interval is small, the output D ₁ of the light-receiving layer 18 is a distribution of two-peak as shown in FIG. 2 (C).

Therefore, in this case, the light receiving layer 18 is
16 is displaced away from, so that an output D ₂ of the light-receiving layer 18 is on the distribution of one peak as shown in FIG. 2 (D).
If this output is subjected to one-time spatial differentiation by the arithmetic circuit 20, the result is as shown in FIG. 2 (E), and its zero cross point corresponds to the center of gravity of the input light pattern. In this way, the center of gravity can be extracted.

The center of gravity extraction described here is mathematically equivalent to the feature extraction by Siebert-Wieman and the like, and according to this embodiment, in addition to the center of gravity extraction described above, it is also possible to detect the end point position and the intersection position of the line.

[Effects of the Invention] As described above, according to the present invention, a novel optical functional device can be provided. Since this optical functional element has the above-described configuration, it can be easily manufactured and can be manufactured in a uniform mass easily, and the edge extraction and the feature extraction can be performed well.

1 and 2, the same result as described above can be obtained even if the light receiving means is removed and the light pattern is directly incident on the diffusion plate 16. That is, as described above, the diffusion plate alone can serve as both the light receiving means and the diffusion means.

Further, the light receiving means, the diffusing means, and the receiving layer may be configured two-dimensionally to perform edge extraction or feature extraction on a two-dimensional light pattern.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining one embodiment of the invention of claim 1, FIG. 2 is a diagram for explaining one embodiment of the invention of claim 2, and FIG. 3 is a diagram for explaining the principle of the invention. Figure to do, 4th
The figure is a diagram for explaining a conventional technique. 10 light receiving element array, 12 control circuit, 14 light emitting element array, 16 diffusion plate, 18 light receiving layer

Claims (2)

(57) [Claims] 1. A light receiving means made of a non-living material for receiving a one-dimensional or two-dimensionally incident light pattern and reproducing the light pattern by light, and a light pattern reproduced by the light receiving means Means for optically diffusing the light into optical signals; and light receiving elements arranged one-dimensionally or two-dimensionally, and arranged at a predetermined distance from the light diffusing means for photoelectrically converting the optical signals. An optical functional device having a layer and signal processing means for performing a spatial differentiation process on an output of the light receiving layer. 2. A light receiving means made of a non-living material for receiving a one-dimensional or two-dimensionally incident light pattern and reproducing the light pattern by light, and a light pattern reproduced by the light receiving means. Diffusion means for optically diffusing the light into optical signals; a light-receiving element in which light-receiving elements are arranged one-dimensionally or two-dimensionally, and a light-receiving layer for photoelectrically converting the optical signal; An optical functional device comprising: a signal processing unit for performing the operation; and a displacement unit for changing a distance between the diffusion unit and the light receiving layer.