JPH0680512B2 - Image recognition device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image recognition device, and more particularly, to a configuration of an incident light path to a target object and a reflection light path from the target object.

(Prior Art) An image recognition device that illuminates an object toward an object and detects reflected light from the object to recognize the object is, for example,
It is widely used as a passbook recognition device in banks and various work recognition devices in factories.

FIG. 4 shows an example of a conventional image recognition device, in which a ring-shaped illumination light source 31 is arranged above a running guide 34 that runs while guiding an object 32 for image recognition such as a passbook. It is designed to illuminate the object 32. A sensor 33 such as a CCD is arranged in the ring of the light source 31.
The illumination light emitted from the light source 31 toward the object 32 is reflected by the object 32, the reflected light is incident on the sensor 33, and the sensor 33 recognizes the image of the object 32 by detecting the incident light. . The light source 31 has a ring shape in order to uniformly illuminate the object 32 and reduce image recognition errors.

(Problems to be Solved by the Invention) The conventional image recognition apparatus as described above is close to the epi-illumination method, and the illumination light for the object 32 has a strong vertical component ray.
Therefore, when the object 32 is printed on both the front and back sides, as in the case of a passbook, the vertical component of the illumination light penetrates the passbook and illuminates the print on the back side of the passbook, which should not be recognized. There is a risk of recognizing. Especially for passbooks, it is necessary to check not only the print contents but also the print character quality such as whether the print is clean and the print location, but if the back side print is recognized However, it becomes impossible to correctly perform the above-mentioned various checks.

The present invention has been made in order to solve the problems of the prior art, and reduces the light amount of the vertical component by making it possible to illuminate the object of image recognition from the lateral direction at a certain angle, It is therefore an object of the present invention to provide an image recognition device that prevents an image on the back side of an object from being erroneously recognized.

(Means for Solving the Problem) The present invention is to provide an incident light path for guiding illumination light from a light source to an object in parallel with a reflected light path in between, and to an object side end portion of an outer wall forming the incident light path. Is provided with an inclined reflection surface for obliquely applying the illumination light to the object, and the inner side wall forming the incident light path or the inclined reflection surface is movable to determine the light amount of the illumination light or the incident angle of the illumination light with respect to the object. It is characterized by being variable.

(Operation) Illumination light that travels from the light source along the incident optical path is reflected by the inclined reflection surface and illuminates the object from an oblique lateral direction at an angle, and the amount of vertical component light is small. The incident light path is arranged so as to sandwich the reflected light path, and the object can be uniformly illuminated. By moving the inner wall forming the incident light path or rotating the inclined reflecting surface, the light amount or the incident angle of the illumination light with respect to the object can be changed, and adjustment is performed to obtain the best illumination. be able to.

(Embodiment) An embodiment of the image recognition apparatus according to the present invention will be described below with reference to FIGS. 1 to 3.

In FIGS. 1 and 2, an imaging lens 7 is arranged above a traveling guide 15 that guides an object 3 for image recognition such as a passbook to travel, and a sensor 8 is arranged above it. . The lens 7 forms an image of the surface of the object 3 on the surface of the sensor 8. The object 3 has a large width dimension to some extent like a passbook, and the sensor 8 is the object 3
It is composed of a CCD sensor array or the like in which a large number of minute elements are arranged in the width direction. Image information of the target object 3 can be obtained by capturing the output of the sensor 8 line by line while the target object 3 is running on the running guide 15 in a direction orthogonal to the array of the sensors 8.

When the optical path that guides the reflected light from the surface of the object 3 to the lens 7 and the sensor 8 is the reflected optical path 20, the incident optical paths 10 and 10 are arranged in parallel on both sides of the reflected optical path 20. The incident light paths 10 and 10 are formed by outer walls 1 and 1 and inner walls 2 and 2 which are arranged in parallel in the vertical direction at predetermined intervals. Further, the two inner side walls 2, 2 are arranged in parallel at a predetermined interval, so that a reflected light path 20 is formed by the inner side walls 2, 2. The front and rear ends of the outer side wall 1,1 and the inner side wall 2,2 are connected by connecting plates 11,11 to form a frame shape as a whole.

As shown in FIG. 3, the inner wall 2 has bent portions at both front and rear ends.
21 and 21 are formed, and the bent portions 21 and 21 are formed with elongated holes 22 and 22 in the upper and lower end portions in the up-and-down direction, respectively, so as to pass through the attachment hole formed in the connecting plate 11 and the elongated hole 22. The inner wall 2 is fixed by screwing a nut into the mounting screw 12.
The inner wall 2 can be moved in the vertical direction within the range of the elongated holes 22,22.

Light sources 4,4, which are lamps and other light emitting bodies, are attached to the upper ends of the incident light paths 10,10 formed by the outer side walls 1,1 and the inner side walls 2,2, and the illumination light from the light sources 4,4 is also attached. Enable incident light path 1
Concave reflectors 9 and 9 for leading to 0 and 10 are mounted behind the light sources 4 and 4. The incident light paths 10 and 10 are for guiding the illumination light from the light sources 4 and 4 to the object 3, and the light sources 4 and 4 are provided along the way.
Diffuser plate for uniformly irradiating the object 3 with the illumination light from the object to provide soft illumination
5,5 are attached. The illumination light from the light sources 4, 4 is obliquely applied to the object 3 at the object-side end of each outer wall 1, 1 forming the incident light path 10, 10, that is, the lower end in FIG. Reflecting members 6 and 6 having inclined reflecting surfaces 6a and 6a are provided. The reflecting members 6, 6 are rotated in a plane perpendicular to the outer walls 1, 1 by means such as connecting the outer members 1, 1 to the outer walls 1, 1 by a horizontal axis and enabling rotation about this axis. Install as much as possible.

The surfaces of the outer side walls 1 and 1 and the inner side walls 2 and 2 on the side of the incident light paths 10 and 10 can be improved in illumination efficiency by making them with mirrors. However, if the illumination efficiency is not a problem, the light-shielding plate of black or another color may be used except for the inclined reflecting surfaces 6a, 6a. The outer side walls 1 and 1 and the inner side walls 2 and 2 have a light shielding function and prevent harmful light from the outside from entering the sensor 8. If the lower ends of the reflection members 6 and 6 are brought close to the object 3 to the extent that the travel of the object 3 is not hindered, the reflection members 6 and 6 perform a light-shielding function, and harmful external light is detected by the sensor. I can't enter 8.

Illumination light emitted from the light sources 4, 4 becomes diffused light by the diffuser plates 5, 5 and is diffused by the inner surfaces of the outer walls 1, 1 and the inner side walls 2, 2 and directed toward the object 3 in the incident light paths 10, 10. Be guided by. The illumination light that has traveled through the incident light paths 10 and 10 is partially reflected by the inclined reflecting surfaces 6a and 6a of the reflecting members 6 and 6 and is obliquely irradiated to the object 3, and the other portion is outside wall 1 , 1 and the inner surfaces of the inner side walls 2, 2 are reflected on the object 3 and then irradiated. As a result, the light source 4,
Most of the illumination light emitted from 4 to the object 3 is emitted obliquely to the object 3, and the vertical component is small. Therefore, the number of light rays that pass through the object 3 is extremely small, and the light rays reflected by the back surface of the object 3 are incident on the sensor 8 and the image on the back surface of the object 3 is erroneously recognized. Disappear.

Here, each inner side wall 2, 2 is moved in the vertical direction within the range of the long hole 22, 22, so that the distance L between the lower end and the surface of the object 3 is L.
Is changed, the light amount of the illumination light reaching the object 3 is changed, and the ratio of the vertical light ray component and the horizontal light ray component included in the illumination light reaching the object 3 is changed. Indirectly, it can be equated with a change in the incident angle of the illumination light with respect to the object 3. Therefore, the height positions of the inner side walls 2, 2 are adjusted so that a sufficient illumination light amount is secured and the illumination light that passes through the object 3 is reduced as much as possible so that the illumination conditions are good. Specifically, while obtaining the output difference between the image signal on the front side and the image signal on the back side, the inner side walls 2, 2 may be fixed at the position where the difference is the largest.

On the other hand, when the reflecting members 6, 6 are rotated to change the angles of the inclined reflecting surfaces 6a, 6a, the incident angle of the illumination light reflected by the inclined reflecting surfaces 6a, 6a and reaching the object 3 to the object 3 Changes. Therefore, also in this case, the reflecting members 6 and 6 are provided in such a manner that a sufficient amount of illumination light is secured and the illumination light that passes through the object 3 is reduced as much as possible.
Adjust the rotation position of. Also in this case, the reflecting member is placed at the position where the output difference between the image signal on the front side and the image signal on the back side is the largest.
Fix 6,6.

As described above, according to the above-described embodiment, the incident light paths 10 and 10 for guiding the illumination light from the light sources 4 and 4 to the object 3 are provided in parallel with the reflection light path 20 in between to form the incident light paths 10 and 10. Since the inclined reflection surfaces 6a, 6a for obliquely irradiating the object 3 with the illumination light are provided at the end portions of the outer side walls 1, 1 on the object side, the illumination light guided to the incident optical paths 10, 10 is obliquely reflected. The object 3 is reflected by the surfaces 6a, 6a and is obliquely irradiated to the object 3, the vertical component of the illumination light with respect to the object 3 is reduced, and the image on the back surface of the object 3 is erroneously detected by the sensor 8. It is prevented from being detected. Further, since the inner side walls 2, 2 forming the incident light paths 10, 10 or the inclined reflecting surfaces 6a, 6a are movable to change the light amount of the illumination light or the incident angle of the illumination light with respect to the object 3, the inner side walls 2 , 2 or the inclined reflecting surfaces 6a, 6a can be adjusted to obtain the best illumination condition, and from this point also, the image on the back surface of the object 3 is erroneously detected by the sensor 8. It is possible to provide a highly accurate image recognition device. In particular, when the object 3 is a passbook, the illumination light is easily transmitted, and in addition, characters or pictures or other patterns are written on the back side, the pattern on the back side may be mistaken. Although it is easy to recognize, according to the above-mentioned embodiment, even if the object 3 is like a passbook, the pattern on the back side is not mistakenly recognized. By the way, even if the backside print density (pcps) of the passbook is 0.9 and the front print density is about 0.3, it is possible to recognize only the front print without misidentifying the back print.

Although the diffuser plates 5 and 5 are not essential to the present invention, if the diffuser plates 5 and 5 are used, the object 3 can be uniformly illuminated with soft illumination light, and the accuracy of image recognition can be improved. It is possible to improve.

In the illustrated embodiment, it has both the vertical position adjusting mechanism of the inner side walls 2, 2 and the rotary position adjusting mechanism of the inclined reflecting surfaces 6a, 6a, but even if only one of them is provided, the desired result is obtained. Can achieve the purpose of. Further, the fixing means of the inner side walls 2, 2 is not limited to screwing, but may be adhesive or the like, and the adjusting means is, for example, an eccentric pin having a pin at a position deviated from the center of rotation and is rotated. The height positions of the inner side walls 2, 2 may be adjusted by changing the height positions of the pins.

The image recognition apparatus according to the present invention can be used, for example, for page mark detection or print range detection of a passbook, detection of presence or absence of various works in a factory, detection of work patterns, etc. It can be widely used without being limited to the type of object.

(Effect of the Invention) According to the present invention, the incident light path for guiding the illumination light from the light source to the object is provided in parallel with the reflected light path in between, and the object is provided at the object side end of the outer wall forming the incident light path. Since an inclined reflection surface for obliquely irradiating the object with the illumination light is provided, the illumination light guided to the incident light path is reflected by the inclined reflection surface and obliquely irradiates the object. The vertical component of the light is reduced, and the image on the back surface of the object is prevented from being erroneously detected by the sensor. Further, since the inner wall or the inclined reflection surface forming the incident light path is movable and the light amount of the illumination light or the incident angle of the illumination light with respect to the object is made variable, the inner wall or the inclined reflection surface can obtain the best illumination condition. Can be adjusted to
Also from this point, it is possible to provide a highly accurate image recognition device in which the image on the back surface of the object is not erroneously detected by the sensor.

[Brief description of drawings]

FIG. 1 is a sectional front view showing an embodiment of an image recognition apparatus according to the present invention, FIG. 2 is a plan view of the same as above, FIG. 3 is a perspective view showing an inner wall in the same embodiment, and FIG. It is a partial cross section front view which shows the example of an image recognition apparatus. 1 ... outer wall, 2 ... inner wall, 3 ... object, 4 ... light source, 6a ... inclined reflecting surface, 10 ... incident light path, 20 ... reflected light path.

Claims (1)

[Claims] 1. An image recognition device for illuminating an object with illumination light and detecting reflected light from the object to recognize the object, wherein an incident light path for guiding the illumination light from the light source to the object is provided. The reflection light path is sandwiched in parallel, and an inclined reflection surface for obliquely irradiating the object with illumination light is provided at the end of the outer wall forming the incident light path on the object side, and the inner wall forming the incident light path. Alternatively, the image recognition device is characterized in that the tilted reflection surface is movable and the light amount of the illumination light or the incident angle of the illumination light with respect to the object is variable.