JPH0373074A - Image input device - Google Patents

Abstract

PURPOSE:To easily realize detection characteristic of on-center type or off-center type by obtaining a cross talk area with an adjacent pair of photoreceptive elements by arranging a light diffusion member at an image forming position at the front of a photoreceptor layer. CONSTITUTION:The photoreceptor layer 11 in which a pair of photoreceptive elements 15 consisting of a center element 14 and a peripheral element 13 are arranged in two-dimensional fashion is provided, and the light diffusion member 12 is arranged at the front of the photoreceptor layer 11. Therefore, the cross talk area with the adjacent pair of photoreceptive elements 15 can be obtained. In such a way, the photoreceptive area in which the peripheral element 13 is larger than the center element 14 on the light diffusion member 12 can be obtained, and the detection characteristic of on-center type or off-center type can be easily obtained by amplifying the output of the center element 14 and the peripheral element 13 with a prescribed ratio and taking a difference between them.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image input device applicable to artificial vision for extracting edge information of an image.

2. Description of the Related Art In recent years, image input devices have been devised that imitate the visual function of living organisms and extract edge information in order to determine the shape of an image.

Therefore, as a conventional example of such an image input device, a device disclosed in Japanese Patent Publication No. 50-34901 will be described with reference to FIGS. 8 to 10. This image input device 1 is a photoreceptor, which corresponds to the retinal photoreceptor cells of the eyeball, in which photoelectric conversion elements 3, which are light receiving elements, are two-dimensionally arranged on the optical axis of an imaging lens 2, which corresponds to the crystalline lens of the eyeball. Layer 4 is arranged. Further, a threshold element layer 6 is provided in which threshold elements 5 having nonlinear characteristics connected to a certain number of the photoelectric conversion elements 3 are two-dimensionally arranged. The line segment direction detection layer 7 connected to this threshold element layer 6 includes, for example, line segment direction detection elements 8 connected to a certain number of the threshold elements 5 and each detecting a specific tilt amount α in each direction. It is formed by a three-dimensional structure in which two-dimensionally arranged layers (not shown) are provided for each layer, and these two-dimensional layers are sequentially connected.

Note that the elements 5 and 8 in each layer 6 and 7 described above are similar to those in the previous layer 4,
6, so that their receiving areas overlap.

In this configuration, in the image input device 1, a projected image (not shown) of the read image 9 is formed on the photoreceptor layer 4 by the imaging lens 2, and each photoelectric conversion element is The contrast of the projected image is detected from the output value of step 3.

An example of a detection mechanism that operates in this manner will be explained based on FIGS. 9 and 10. first.

- N photoelectric conversion elements 3. - threshold elements 5 have reception areas arranged in a matrix. In case 1 consisting of ~3n, for example,
One photoelectric conversion element 3 located at the center of the array and each photoelectric conversion element 3 located around this are connected to a weighting coefficient circuit (Fig. (not shown) to the threshold element 5. Therefore, each photoelectric conversion element 3. Assuming that the output values of ~3n are U1~Un and the weighting coefficients at the time of input are 01~Cn, the input value Nij to the threshold element 5 is as follows: N1j=CIU□+C2U, +-CnUn.

Note that these weighting coefficients C1 to Cn are set by, for example, providing an inverter circuit, a resistor, or the like between each of the photoelectric conversion elements 3□ to 3n and the threshold element 5. Therefore, as illustrated in FIG. 10, the detection characteristic of the threshold element 5 is an on-center type in which the output of the photoelectric conversion element 3 located at the center of the receiving area is treated as positive, and the output of the surrounding photoelectric conversion elements 3 is treated as negative. becomes.

Furthermore, the output value Ulj of the threshold element 5 is output according to the function Uij=11: child 1'=L'+h. However, e is the input value from the photoelectric conversion element 3 at the center position to the threshold element 5, and h is the sum of the input values from the surrounding photoelectric conversion elements 3 to the threshold element 5. Therefore, this photoelectric conversion element 3. If the edge of the projected image exists within the acceptance area of .about.3n, the threshold element 5 will output a positive output value Ujj according to the function described above.

In other words, when the projected image covers the central photoelectric conversion element 3, the output value Uij of the threshold element 5 is large, and when the projected image is projected on the side of the receiving area, the output value Uij of the threshold element 5 is large.
j is small. In addition, in the receiving area where the projection image is not projected or the receiving area is completely covered, the output value Ui of the threshold element 5
j is O.

Then, these output values Ulj are input to the line segment direction detection layer 7, and the line segment direction detection elements 8 corresponding to each line segment of the projected image are inputted to the line segment direction detection layer 7.
Thus, the amount of inclination of the line segment existing at the position (x, y) on the photoreceptor layer 4 is detected.

Problems to be Solved by the Invention In the image input device 1 described above, weighting coefficients C2 to C2 are applied to the plurality of photoelectric conversion elements 3□ to 3n forming one receiving area.
By setting Cn, on-centered detection characteristics are obtained. However, in order to set the weighting coefficients 01 to Cn, it is necessary to provide a weighting coefficient circuit consisting of a resistor, an inverter circuit, etc. for each photoelectric conversion element 3, and a large number of circuit components are required for one receiving area. etc., the photoreceptor layer 4
The circuit configuration of the threshold element layer 6 and the threshold element layer 6 is extremely complicated, and the productivity of the device is low.

Means for Solving the Problem A photoreceptor layer is provided in which a large number of photoreceptive elements are arranged two-dimensionally, and outputs from each of the plurality of photoreceptor elements are received to generate an output equal to a function of a weighted sum. In an image input device that includes a threshold element layer in which threshold elements are two-dimensionally arranged and extracts edge information corresponding to an image that is optically input to a photoreceptor layer, A photoreceptor layer in which element sets are two-dimensionally arranged is provided, and a light diffusing member is placed at an image forming position in front of the photoreceptor layer.

A photoreceptor layer is provided in which a photoreceptor element set consisting of an action center element and a peripheral element is arranged two-dimensionally, and a light diffusing member is placed at an image forming position in front of this photoreceptor layer. A crosstalk area with the light receiving element set is obtained, and the receiving area on the light diffusing member is such that the peripheral elements are larger than the central element, and the outputs of the central element and the peripheral elements are amplified at a predetermined ratio. On-center type or off-center type detection characteristics can be easily obtained by taking the difference.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 7. Note that the same parts as those in the image input device 1 described above are given the same names and symbols, and the description thereof will be omitted. First, in the image input device 10 of this embodiment, the imaging lens 2 and the photoreceptor layer 1
A light diffusing member 12 is disposed between the light diffusing member 1 and the light diffusing member 12. On the other hand, here, an annular peripheral element 13 protruding in the optical axis direction and a central element 14 surrounded by this peripheral element 13 are integrated to form a photoreceptor element set 15 having a photoelectric conversion function, This photoreceptor element set 15 is two-dimensionally arranged in the photoreceptor layer 11. Therefore, these photoreceptor element sets 1
5 is an amplifier 16 connected to each of the elements 13 and 14;
．． 17 and a differential amplifier 8 to the threshold element 5. In this image input device 10, as illustrated in FIG. 1, the photoreceptor 7I'll and the arithmetic circuit 19, which is a threshold element layer, are easily connected by forming each unit into a unit.

With such a configuration, this image input device 10 functions in substantially the same way as the image input device 1 described above.

Here, in this image input device 10, the photoreceptor element set 15
A central element 14 is surrounded by an annular and protruding peripheral element 13, and a light diffusing member 12 is disposed on the optical path.Therefore, when a light spot moves on the light diffusing member 12, the central element 14 As illustrated in FIG. 3(a), the output is large when the light spot is located approximately at the center of the photoreceptor element set 15, and decreases rapidly when the light spot deviates from this point. This is because the diffused light incident on the central element '1.4 is blocked by the annularly protruding peripheral element 13 when its angle of incidence is inclined. On the other hand, when the light spot moves on the light diffusing member ↓2 in the same manner as described above, the output of the peripheral element 13 is as shown in FIG. It is at its maximum when located at the center, and gradually decreases as it moves away from this point.

Therefore, in this image input device 10, the outputs of the peripheral element 13 and the center element 14 exhibiting the above-mentioned characteristics are amplified to a predetermined ratio by the amplifiers 16 and 17, and then the difference is taken by the differential amplifier 18. , as illustrated in FIG. 3(c), an on-centered output characteristic is easily obtained.

In the image input device 10 of this embodiment, each photoreceptor element set 15 has a double circular structure, and the peripheral element 13 and the central element 14 are arranged in a double circular structure.
Since the threshold element is formed by two elements, the number of wirings to each threshold element is extremely reduced, and the productivity of the device is improved. Further, in this image input device 10, the light diffusion member 2 for diffusing the projected image of the read image 9 is arranged on the optical path leading to the photoreceptor layer 11. For example, the photoreceptor layer 11 is By making it slidable in the axial direction, the area of the projected image that is received here can be adjusted. In this case, since the detection range of the photoreceptor element set 15 is expanded or contracted, the photoreceptor layer 11
The size of the receptive area can be changed. Further, in the image input device 10 of this embodiment, the photoreceptor element set 15 is connected to the surrounding element 1.
3 and the central element 14 are integrated, but the present invention is not limited to this. As illustrated in FIG. 14 may be formed continuously. In this case, the characteristics, arrangement, etc. of each element 13, 14 can be made strictly uniform, and a device with stable performance can be obtained with high productivity. Furthermore, as illustrated in FIG.
1, and in this case, the productivity of the device can be further improved. Further, as illustrated in FIG. 6, it is also possible to form the elements 13 and 14 on the same plane on the two substrates 22, and in this structure, the arrangement of the elements 13 and 14 is Accordingly, the receiving area on the light diffusing member 12 can be set. Figure 7 (a
), (b), even in this case, each element 13
．． The outputs of 14 exhibit different characteristics, and by amplifying these outputs to a predetermined ratio with amplifiers 16 and 17 and then taking the difference with a differential amplifier 18, as illustrated in FIG. 7(c), On-centered output characteristics can be easily obtained.

Effects of the Invention As described above, the present invention provides a photoreceptor layer in which a large number of photoreceptive elements are two-dimensionally arranged, receives the outputs from the plurality of photoreceptive elements, and converts the outputs into a function of a weighted sum. In an image input device that includes a threshold element layer in which threshold elements that generate the same output are arranged two-dimensionally, and extracts edge information corresponding to an image that is optically input to a photoreceptor layer, a central element and peripheral elements are arranged. By providing a photoreceptor layer in which photoreceptor sets consisting of a two-dimensional arrangement of photoreceptor elements, and arranging a light diffusing member at an image forming position in front of this photoreceptor layer, there is no interference between adjacent photoreceptor element sets. A crosstalk area is obtained, and the receiving area on the light diffusing member is such that the peripheral elements are larger than the central element, and the outputs of the central element and the peripheral elements are amplified at a predetermined ratio to take the difference. It is possible to easily obtain on-center type or off-center type detection characteristics using It is also possible to form the light-receiving element set with two light-receiving elements having a double circular structure, and in this case, the structure and wiring of the device can be further simplified.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of a photoreceptor, FIG. 3(a) is a characteristic diagram showing the output of the central element of the photoreceptor, and FIG. 3(b) ) is a characteristic diagram showing the output of the peripheral elements of the photoreceptor, Figure 3 (Q) is a characteristic diagram showing the detected value input from the photoreceptor to the threshold element, and Figures 4 to 6 are the characteristics of the photoreceptor. FIG. 7 is a longitudinal side view showing a modified example of the layer; (a) is a characteristic diagram showing the output of the central element of the photoreceptor;
FIG. 7(b) is a characteristic diagram showing the output of surrounding elements of the photoreceptor element, FIG. 7(Q) is a characteristic diagram showing the detected value input from the photoreceptor element to the threshold element, and FIG. 8 is a conventional example. FIG. 9 is an explanatory diagram showing the connection state between the photoreceptor element set of the photoreceptor layer and the threshold element of the threshold element layer, and FIG. 10 is an explanatory diagram of the formation of an on-center type detection characteristic. be. 5... Threshold element, 10... Image input device, 11...
Photoreceptor layer, 12... Light diffusing member, 13... Surrounding element, 14... Center element, 15... Photoreceptor element set, 1
9...threshold element layer j [F] anti-1'' luck

Claims (1)

[Claims] A photoreceptor layer is provided in which a large number of photoreceptor elements are arranged two-dimensionally, and a threshold element that receives outputs from the plurality of photoreceptor elements and generates an output equal to a function of a weighted sum is provided. In an image input device that includes a threshold element layer arranged in a symmetrical manner and extracts edge information corresponding to an image that is optically input to the photoreceptor layer, a photoreceptor element set consisting of a center element and peripheral elements is arranged in a two-dimensional manner. What is claimed is: 1. An image input device comprising: a photoreceptor layer arranged in a vertically arranged manner, and a light diffusing member disposed at an image forming position in front of the photoreceptor layer.