JPH0447468A - Picture recognizing device - Google Patents

Abstract

PURPOSE:To prevent erroneous detection of the rear face picture of an object by providing an object side end part of an outside wall, which forms an incidence optical path, with an inclined reflection face by which the object is obliquely irradiated with illuminating light. CONSTITUTION:Illuminating light emitted from light sources 4 and 4 is converted to diffused light by diffusing plates 5 and 5 and is led toward an object 3 in incidence optical paths 10 and 10 while being irregularly reflected by inside faces of inside walls 2 and 2, and a part of this light is reflected by inclined reflection faces 6a and 6b of the reflecting members 6 and 6 and is obliquely thrown to the object, and another part is thrown to the object 3 after being reflected by inside faces of outside walls 1 and 1 and inside walls 2 and 2. As the result, most of illuminating light is obliquely thrown to the object 3, and consequently, light transmitted through the object 3 is extremely reduced, and erroneous recognition of the picture on the rear face due to incidence on a sensor 8 of the light reflected by the rear face of the object 3 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image recognition device, and particularly to the configuration of an incident optical path to an object and a reflected optical path from the object.

(Prior art) The image recognition error that recognizes the object by irradiating illumination light toward the object and detecting the reflected light from the object is, for example,
It is widely used as a recognition device for passbooks in banks and various workpieces 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 traveling guide 34 that guides and runs an object 32 for image recognition such as a bankbook. The object 32 is illuminated. A sensor 33 made of a CCD or the like is arranged within the ring of the light source 31.

Illumination light emitted from the light source 31 toward the object 32 is reflected by the object 32, and this reflected light enters the sensor 33, and the sensor 33 recognizes the object 32 as an image by detecting this incident light. . The reason why the light source 31 is ring-shaped is 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 similar to an epi-illumination method, and the illumination light for the object 32 has a strong vertical component. Therefore, when the object 32 has printing on both the front and back sides, such as a passbook, the vertical component of the illumination light passes through the passbook and illuminates the print on the back side of the passbook, causing the print on the back side that should not be recognized in the first place. There is a danger that they will recognize this. In particular, if it is for a passbook, it is necessary to check not only the printed content, but also the quality of the printed characters, such as whether the printing is clean, and the location of the printing. , it becomes impossible to correctly perform the various checks mentioned above.

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

(Means for Solving the Problems) The present invention provides an incident optical path that guides illumination light from a light source to an object in parallel with a reflected optical path in between, and attaches the incident optical path to the object side end of the outer wall that forms the incident optical path. In this method, an inclined reflective surface is provided to obliquely apply the illumination light to the object, and the inner wall forming the incident optical path or the inclined reflective surface is movable to adjust the amount of illumination light or the angle of incidence of the illumination light on the object. It is characterized by being variable.

(Function) The illumination light that has traveled from the light source along the incident optical path is reflected by the inclined reflection surface and is irradiated to the object from a diagonal horizontal direction at a certain angle, and the amount of light of the vertical component is small.

The incident optical path is arranged to sandwich the reflected optical path, so that the object can be uniformly illuminated. By moving the inner wall that forms the incident light path or rotating the inclined reflective surface, the amount of illumination light or the angle of incidence on the object can be varied, thereby adjusting for the best illumination. be able to.

(Example) Hereinafter, an example of the image recognition apparatus according to the present invention will be described with reference to FIGS. 1 to 3.

In FIGS. 1 and 2, an imaging lens 7 is disposed above a travel guide 15 that guides an object 3 for image recognition such as a bankbook while traveling, and a sensor 8 is further above the travel guide 15.
is located. Lens 7 forms an image of the surface of object 3 onto the surface of sensor 8 . The object 3 has a relatively large width, such as a bankbook, and the sensor 8 is a CCD sensor array or the like in which a large number of minute elements are arranged in the width direction of the object 3. Image information of the object 3 can be obtained by capturing the output of the sensor 8 line by line while moving the object 3 on the travel guide 15 in a direction perpendicular to the array of sensors 8.

Assuming that the optical path that guides the reflected light from the surface of the object 3 to the lens 7 and the sensor 8 is a reflected optical path 20, incident optical paths 10 and 10 are arranged in parallel on both sides of the reflected optical path 20. The incident optical path 10.10 consists of outer walls 1, 1 and inner walls 2, 2, which are arranged parallel to each other in the vertical direction at a predetermined interval.
is formed by. Further, since both inner walls 2, 2 are arranged in parallel with a predetermined interval, a reflected optical path 20 is formed by these inner walls 2, 2.

Connecting plates 11 are provided at both front and rear ends of the outer walls 1, 1 and the inner walls 2, 2.
．． 11, and is formed into a frame shape as a whole.

As shown in FIG. 3, the inner wall 2 has bent portions 21.21 formed at both front and rear ends, and each bent portion 21.21 has elongated holes 22, 22 formed at both upper and lower ends thereof in the vertical direction. formed in
The inner wall 2 is fixed to the connecting plate 11 by screwing nuts into the mounting screws 12 passed through the holes and the elongated holes 22. The inner wall 2 has the elongated hole 22.22.
It can be moved up and down within the range.

Each incident optical path 1 is formed by an outer wall 1,1 and an inner wall 2,2.
At the upper end of 0.10 is a light source 4 consisting of a lamp or other light emitting body.
, 4 are attached, and a concave reflector 9, for effectively guiding the illumination light from the light source 4.4 to the incident optical path 10.10.
9 is mounted behind the light sources 4,4. Incident optical path 1
0.10 is for guiding the illumination light from the light sources 4, 4 to the object 3, and along the way, the illumination light from the light sources g4, 4 is uniformly irradiated onto the object 3 to provide soft illumination. in order to,
A diffuser plate 5.5 made of, for example, a milky white acrylic plate is attached. At the object side ends of each of the outer walls 1, 1 forming the incident optical path 10.10, that is, at the lower end in FIG. Reflective members 6, 6 having inclined reflective surfaces 6a, 6a
is provided. The reflective members 6, 6 are connected to the outer wall 1.
.

The surfaces of the outer walls 1, 1 and the inner walls 2, 2 on the 10° 10 side of the incident optical path can be made of mirrors to improve illumination efficiency. However, if illumination efficiency is not an issue, except for the inclined reflective surfaces 6a, 6a, black or other colored light shielding plates may be used.

The outer walls 1, 1 and the inner walls 2, 2 have a light blocking function and prevent harmful light from entering the sensor 8 from the outside. If the lower ends of the reflective members 6, 6 are placed close to the object 3 to the extent that they do not interfere with the running of the object 3, the reflective members 6, 6 will perform a light shielding function, and harmful external light will be blocked by the sensor. It's never going to be 8.

The illumination light emitted from the light sources 4, 4 becomes diffused light by the diffuser plates 5, 5, and is diffusely reflected by the inner surfaces of the outer walls 1, 1 and the inner walls 2°2, while traveling in the incident optical path 10.10 toward the object 3. be guided. Part of the illumination light that has traveled through the incident optical path 10° 10 is reflected by the inclined reflection surfaces 6a, 6a of the reflection members 6, 6 and is irradiated obliquely to the object 3, and the other part is reflected by the outer wall 1. , 1 and the inner surfaces of the inner walls 2, 2, and then irradiated onto the object 3. As a result, from the light sources 4, 4 to the object 3
Most of the illumination light irradiated onto the object 3 is irradiated 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 reduced, and the light rays reflected from the back surface of the object 3 enter the sensor 8 and
This eliminates the possibility of the image on the back side being mistakenly recognized.

Here, if each inner wall 2, 2 is moved vertically within the range of its elongated holes 22, 22 and the distance between its lower end and the surface of the object 3 is changed, the illumination reaching the object 3 As the amount of light changes, the ratio of vertical light ray components and horizontal light ray components included in the illumination light reaching the object 3 changes, and indirectly the illumination light toward the object 3 changes. This can be equated with a change in the angle of incidence of Therefore, the height positions of the inner walls 2, 2 are adjusted so as to provide good illumination conditions such that a sufficient amount of illumination light is ensured and the amount of illumination light transmitted through the object 3 is minimized. Specifically, while determining the output difference between the image signal on the front side and the image signal on the back side, the inner walls 2, 2 may be fixed at the position where the difference is the largest.

On the other hand, the reflective members 6, 6 are rotated so that their inclined reflective surfaces 6a
, 6a, the same inclined reflecting surfaces 6a, 6a
The angle of incidence of the illumination light that is reflected by the object 3 and reaches the object 3 changes. Therefore, in this case as well, the rotational positions of the reflecting members 6, 6 are adjusted so as to provide good illumination conditions such that a sufficient amount of illumination light is ensured and the amount of illumination light transmitted through the object 3 is minimized. do. In this case as well, the reflecting members 6, 6 are fixed at the position where the output difference between the front side image signal and the back side image signal is the largest.

As described above, according to the above embodiment, the incident optical paths 10, 10 for guiding the illumination light from the light sources 4, 4 to the object 3 are provided in parallel with the reflected optical path 20 in between, thereby forming the incident optical path 10.10. Since the outer walls 1, 1 are provided with inclined reflection surfaces 6a, 6a on the object side ends for obliquely applying the illumination light to the object 3, the illumination light guided to the incident optical path 10.10 is reflected obliquely. Surface 6a.

6a and illuminates the object 3 obliquely, the vertical component of the illumination light toward the object 3 decreases, and the sensor 8 mistakenly detects an image of the back side of the object 3. This will be prevented. Also, the inner walls 2, 2 or the inclined reflective surfaces 6a, 6a forming the incident optical path 10.10
is movable, and the amount of illumination light or the angle of incidence of the illumination light on the object 3 is made variable, so that the inner walls 2, 2 or the inclined reflective surfaces 6a, 6a can be adjusted so as to obtain the best illumination conditions. From this point of view as well, it is possible to provide a highly accurate image recognition device in which the image of the back surface of the object 3 is not detected by the sensor 8 erroneously. In particular, if the object 3 is a passbook that easily transmits illumination light and has letters, pictures, or other patterns written on the back side, the pattern on the back side may be mistakenly marked. Although it is easy to recognize, according to the above embodiment, even if the object 3 is something like a bankbook, the pattern on the back side will not be erroneously recognized. Incidentally, even if the print density (peps) on the back of a passbook is 0.9 and the print density on the front is about 0.3, only the print on the front can be recognized without misrecognizing the print on the back.

Although the diffusion plates 5, 5 are not essential to the present invention,
By using the diffuser plates 5, 5, the object 3 can be uniformly illuminated with soft illumination light, and the accuracy of image recognition can be improved.

The illustrated embodiment has both the vertical position adjustment mechanism for the inner walls 2, 2 and the rotational position adjustment mechanism for the inclined reflective surfaces 6a, 6a, but even if only one is provided, the desired effect can be achieved. can reach the purpose of Further, the means for fixing the inner walls 2, 2 is not limited to screwing, but may also be adhesive, etc., and the means for adjusting them may also be, for example, using an eccentric pin having a pin at a position 90 degrees from the center of rotation, and rotating the eccentric pin. The height position of the inner walls 2, 2 may be adjusted by changing the height position of the pin.

The image recognition device according to the present invention can be used, for example, to detect page marks and print areas of bankbooks, and can also be used to detect the presence or absence of various workpieces in factories, detect patterns on workpieces, etc.

It can be widely used without being limited to other types of objects.

(Effects of the Invention) According to the present invention, the incident optical path that guides the illumination light from the light source to the target object is provided in parallel with the reflected optical path in between, and the object side end of the outer wall forming the incident optical path is Since a tilted reflective surface is provided to illuminate the object obliquely, the illumination light guided to the incident optical path is reflected by the tilted reflective surface and is irradiated diagonally to the target object, reducing the illumination of the target object. The vertical component of the light is reduced, which prevents the image of the back side of the object from being erroneously detected by the sensor. In addition, the inner wall or the inclined reflective surface that forms the incident optical path is movable to vary the amount of illumination light or the angle of incidence of the illumination light on the object, so that the inner wall or the inclined reflective surface can be used to provide the best illumination conditions. It is possible to adjust the
Also from this point of view, it is possible to provide a highly accurate image recognition device in which the image of the back side of the object is not detected by the sensor erroneously.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional front view showing an embodiment of the image recognition device according to the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a perspective view showing an inner wall in the embodiment, and FIG. 4 is a conventional 1 is a partially sectional front view showing an example of an image recognition device. 1...Outer wall, 2...Inner wall, 3...Object. 4... Light source, 6a... Inclined reflective surface, 10... Incident optical path, 20... Reflective optical path.

Claims (1)

[Claims] In an image recognition device that recognizes an object by emitting illumination light toward the object and detecting reflected light from the object, an incident optical path that guides illumination light from a light source to the object is provided. , are provided parallel to each other with the reflected optical path in between, and an inclined reflective surface for obliquely applying illumination light to the object is provided at the object-side end of the outer wall forming the incident optical path, and the inner side forming the above-mentioned incident optical path is An image recognition device characterized in that the wall or the inclined reflective surface is movable to vary the amount of illumination light or the angle of incidence of the illumination light on the object.