JPH0452875A - Image input device - Google Patents

Abstract

PURPOSE:To accurately enter the image of the whole work without generating uneven lighting by arranging a reflecting member so as to surround a space between a lighting means and an image entry part. CONSTITUTION:The lighting means 18, the image entry part 19 and an image input means 20 are arranged in a case 15 so that the means 18 is arranged between the part 19 and the means 20. In addition to the reflecting member 10, reflecting plates 11 to 13 are arranged in a space formed by diffusion plates 2, 2 and an upper roof 16 so as to surround the periphery of the space. The reflecting plate 11 is fixed on the inwall face of the case 15 along the string of light sources 4 and the reflecting plates 12, 13 are fixed on both the sides of the light source string. The reflecting plates 12, 13 are fixed with the inclination of a proper angle so as to efficiently reflect illuminating light. Since the reflecting plates 11 to 13 are arranged so as to surround the upper space of the diffusion plates 2, an image signal can be accurately obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image input device, for example,
This can be used to determine whether a work is correct or not, or whether it is good or bad, through image processing.

(Prior Art) For example, an image processing apparatus requires an image input device for inputting an image signal of a workpiece to the processing apparatus. An image input device basically includes a workpiece mounting section and a camera or an imaging optical system disposed opposite to a surface to be inspected of the workpiece placed on the mounting section.

However, in conventional image input devices, the workpiece placement section, illumination means, and image input means are individually manufactured and arranged individually, which causes the problem that the entire system becomes large. Easily affected by external light,
Problems such as uneven lighting tend to occur, and in order to eliminate these problems as much as possible, the light source had to be strengthened.

Therefore, the present applicant proposed a case having an image capture section for capturing an image of the imaged surface of the workpiece, an image input means attached to this case for inputting an image of the imaged surface of the workpiece, and an image inputting means for inputting the imaged surface of the workpiece. We previously filed a patent application regarding an image input device that includes an illumination device installed between a capture unit and an image input device to illuminate the imaged surface of a workpiece. This is patent application No. 1-225121.

8 to 1-0 show examples of image input devices that are substantially the same as the image input device according to the above application.

In FIGS. 8 to 1o, a rectangular parallelepiped case 15
Inside, one half of the case 15 in the longitudinal direction (the left half in FIG. 9) is provided with illumination means 18 on both sides in the width direction.
．． 18 are arranged in pairs. Lighting means 18.1
Each light source 8 has a plurality of light sources 4, 4 and a diffuser plate 2, 2 disposed above the light sources 4, 4. The light source 4 is, for example, an LE
A plurality of light sources 4 are arranged in rows on the substrate, and one row of light sources 4 and the other row of light sources 4 are mutually shifted in the row direction and arranged in a staggered manner.

The illumination light from the pair of illumination means 18.18 is transmitted through the diffusion plates 2, 2.
The light is diffused and reaches the top plate 16 of the case 15, to which a transparent rectangular cover glass 1 is fixed. The portion of the top plate 16 that includes the cover glass 1 serves as an image capturing section 19, as indicated by the arrow in FIG.

A workpiece 9 is conveyed over the cover glass 1, crossing the cover glass 1 in the width direction. Work 9
is, for example, a coin or medal, and the cover glass 1
The lower surface of the workpiece 9 in contact with the upper surface is the imaged surface.

A mirror 3 is disposed obliquely at approximately 45° between the pair of illumination means 18.18. The mirror 3 is formed into an elongated rectangle. The diagonal direction of the mirror 3 is such that light from above is reflected to the right in FIG. Work 9
The reflected light from the imaged surface is reflected laterally by the mirror 3 and guided to an image input means 20 comprising an imaging optical system, a line sensor, and the like. The image input means 20 is the illumination means 18
An image of the imaged surface of the workpiece 9 illuminated by the angle 18 is detected line by line in a direction orthogonal to the transport direction of the workpiece 9 and output as an image signal.

This image signal is input to an image processing device or the like.

According to the above-mentioned image input device, the entire system can be made compact, it is less susceptible to interference from external light, there is no uneven illumination, and there is no need to strengthen the light source, which are excellent effects.

(Problems to be Solved by the Invention) However, even with the image input device which has the above-mentioned excellent effects, there are still problems to be solved.

In order to satisfy the condition of compacting the whole, it is necessary to arrange a plurality of light sources 4 constituting the illumination means 18 in a straight line in one direction, and to illuminate the workpiece 9 evenly from all directions. The problem is that the image of a part of the workpiece 9 cannot be captured clearly. The reason will be explained in more detail.

Sufficient illumination light is irradiated onto the imaged surface from the array direction of the plurality of light sources 4, and sufficient illuminance can be obtained.
, B, there is almost no illumination light directed toward the imaged surface from both ends of the light source 4 in the arrangement direction. Therefore, as shown in FIG. 11, when the work 9 is assumed to be a coin, and the transport direction of the work 9 is the direction of the arrow S, the illumination range of the work 9 by the light source 4 is indicated by the symbol E in FIG. , it becomes a narrow range in the direction orthogonal to the above-mentioned conveyance direction.

The illumination ranges at both ends of this illumination range E, indicated by symbols a and b in FIG. 11, are ranges to be illuminated from both ends in the arrangement direction of the light sources 4, as shown by arrows A and B. However, as described above, since there is almost no illumination light directed from both ends of the light source 4 in the arrangement direction toward the imaged surface, there are problems in the above ranges a and b that the uneven shape clearly appears and the accuracy of image processing deteriorates. be.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to accurately capture an image of the entire workpiece without uneven illumination, so that correct image processing can be performed. The purpose is to provide processing equipment.

(Means for Solving the Problems) The present invention includes: an image capturing unit that captures an image of the imaged surface of a work; an image input unit that inputs an image of the imaged surface of the work; an image capturing unit; and an image input unit. An image input device comprising: illumination means installed between the workpiece and illuminating the imaged surface of the workpiece.

The present invention is characterized in that a reflecting member that reflects illumination light from the illumination means toward the imaged surface of the workpiece is arranged so as to surround the space between the illumination means and the image capturing section.

(Function) The illumination means illuminates the imaged surface of the workpiece located in the image capturing section. An image of the imaged surface is captured by an image input means and input to an image processing device or the like. A reflecting member arranged to surround the space between the illumination means and the image capturing section reflects the illumination light from the illumination means toward the imaged surface of the workpiece. At this time, the reflecting member can be regarded as equivalent to a ring illumination means, and the illumination range on the imaged surface can be uniformly illuminated.

(Embodiments) Hereinafter, embodiments of the image input device according to the present invention will be described with reference to the drawings. In addition, Figures 8 to 10
Common reference numerals are used for components common to those in the illustrated example.

1 to 4, inside the rectangular parallelepiped-shaped case 15, illumination means 18.
18 are arranged in pairs. Lighting means 18.18
each has a plurality of lights g4, 4 and a diffuser plate 2, 2 arranged above them. The light source 4 is, for example, an LED.
A plurality of light sources 4 are arranged in rows on the substrate, and one row of light sources 4 and the other row of light sources 4 are mutually shifted in the row direction and arranged in a staggered manner. has been done. In this embodiment, each of the light sources 4, 4 has a directivity by forming the emitting portion of the illumination light in the shape of a convex lens, and the illumination light emitted upward from the directional light sources 4.4 is directed to a diffuser plate. It is spread by 2,2. Each diffuser plate 2, 2
A mirror 10.10 is installed obliquely above the light source 4.
Mirrors 10 and 10 reflect the illumination light diagonally upward after exiting from the angle 4 and being diffused by the diffuser plates 2, 2.

The number of rows of light emitting elements and the total number of light emitting elements constituting the light source 4 may be changed as appropriate depending on the size of the workpiece, its material, etc., which will be described later.As the light source 4, in addition to LEDs, halogen lamps, fluorescent tubes, and cathode rays can be used. A tube or the like may also be used.

The illumination light from the pair of illumination means 18.18 is transmitted through the diffusion plates 2, 2.
The light is diffused by the mirrors 10 and 10 and reflected by the mirrors 10 and 10 to reach the top plate 16 of the case 15, to which the transparent cover glass 1 is fixed. The cover lath 1 has a rectangular shape and is fixed with its longitudinal direction facing the longitudinal direction of the case 15. Further, the cover glass 1 is attached so that the upper surface of the cover glass 1 is embedded in the window hole of the top plate 16 so that the upper surface of the cover glass 1 coincides with the upper surface of the above-mentioned top plate 16.

The portion of the top plate 16 that has the cover glass 1 serves as an image capturing section 19, and as shown by the arrow in FIG.
It is designed to be conveyed across the width direction. The workpiece 9 is, for example, a coin or a medal, and the lower surface of the workpiece 9 that is in contact with the upper surface of the cover glass 1 is an imaged surface 9a.

The imaged surface 9a of the workpiece 9 passes through each of the mirrors 10 and 10 mentioned above.
The angle of incidence θ of the illumination optical axis toward the imaged surface 9a is approximately 45″,
angle is set.

A mirror 3 is disposed obliquely at approximately 45'' between the pair of illumination means 18, 18. The mirror 3 is formed into an elongated rectangle. The mirror 3 may be constituted by a prism.

The diagonal direction of the mirror 3 is such that light from above is reflected to the right in FIG.

The reflected light from the imaged surface 9a of the workpiece 9 is reflected laterally by the mirror 3 and reaches the imaging optical system 5. The imaging optical system 5 is
An image of the imaged surface 9a of the workpiece 9 is formed on the line sensor 6. The focus of the imaging optical system 5 can be adjusted using a focus adjustment member.

The line sensor 6 is fixed via an optical axis adjustment member 7 to one half of the case 15 in the longitudinal direction, which is opposite to the part where the illumination means 18.18 is arranged.

The line sensor 6 detects an image of the imaged surface 9a of the workpiece 9 illuminated by the illumination means 18, 18 line by line in a direction orthogonal to the conveyance direction of the workpiece 9, and outputs it as an image signal. This image signal is manually input to an image processing device or the like. A portion including the imaging optical system 5 and the line sensor 6 constitutes an image input means 20.

As described above, the illumination means 1 is placed in one case 15.
8.18, an image capture section 19 and an image input means 20 are installed, and an illumination means 18.18 is installed between the image capture section 19 and the image input means 20.

In the space formed by the diffuser plates 2, 2 and the top plate 16 above them, in addition to the mirrors 10 and 10 as reflecting members described above, there are reflecting plates 11 and 12 as reflecting members surrounding the space. , 11°13 are arranged. The reflecting plates 11.11 are fixed to the inner wall surface of the case 15 along the rows of the light sources 4,4. The reflecting plates 12 and 13 are provided with appropriate members such as cases 15 at both ends of each row of light sources 4 and 4.
It is fixed to a member that extends the inside of the case 15 in the longitudinal direction, an inner wall surface of the case 15, or the like. In addition, the reflectors 12 and 13 efficiently direct illumination light from the light sources 4 and 4 to the imaged surface 9a.
It is tilted and fixed at an appropriate angle so that it can be reflected towards the target.

The reflective surfaces of the reflective plates 11, 12, 11, and 13 can be made of vapor-deposited aluminum, a glossy aluminum plate, or the like.

In this way, by arranging the reflection plates 11, 12, 11.13 so as to surround the space above the diffusion plates 2, 2, the illumination light that is diffused by the diffusion plates 2, 2 and tends to leak to the surroundings can be covered. can be reflected toward the lath 1, and the illuminance on the imaged surface 9a can be improved by about 10%. Furthermore, each reflector 1.1, 12, 11, 13 can be considered as an indirect illumination source, which surrounds the space between the illumination means 18 and the image capture part 19. Since the illumination device is arranged in the same manner as a ring illumination with respect to the surface to be imaged 9a, the surface to be imaged 9a can be illuminated with a uniform amount of light without uneven illumination.

FIG. 5 shows the workpiece 9 illuminated in this way. Assuming that the coin-shaped workpiece 9 is conveyed in the direction of the arrow, the range g! of both ends of the workpiece 9 in the conveyance direction! 110A also refers to the range 1 at both ends in the direction orthogonal to the transport direction of the workpiece 9.
2A and 13A are also uniformly illuminated. By the way, the range indicated by the above code 10A is the mirror 10.10 and the reflector 1.
1. ,,1.1 The illumination range by the reflected illumination light is
Code 12A.

The ranges indicated by L3A indicate the illumination ranges by the illumination light reflected by the reflection plates 12 and 13, respectively. In this way, by arranging the reflectors 11, 12, 11, and 13 so as to surround the space between the illumination means 18 and the image capture unit 19, the workpiece 9 can be uniformly illuminated over the entire range. 5 The imaged surface 9 can be input to the image input unit 20.
The unevenness or pattern of a is clearly highlighted, and the image of the workpiece 9 can be clearly captured. Incidentally, the dots shown on the peripheral edge of the workpiece 9 in FIG. 5 are dots on a 500 yen coin, etc., and such dots can be made to stand out clearly over the entire circumference.

In the above embodiment, one image capture unit 19 and an image input unit 2
Since the illumination means 18.18 is installed between 0 and 0,
If no measures are taken for the illumination means 18.18, the illumination light from the illumination means 18.18 will directly illuminate the image power means 20.
There is a risk that the light may enter the camera and deteriorate the image. Therefore, light shielding plates 8, 8 are erected between each of the light sources 4, 4 and the mirror 3 to prevent the illumination light from the light sources 4, 4 from directly entering the image input means 2o.

The case 15 houses all of the constituent members,
It also serves to shield ambient light so that it does not affect the image signal.

Now, when illumination light is emitted from the light sources 4, 4, the illumination light is diffused by the diffusion plates 2, 2, and is further reflected by the mirrors 10, 10 to uniformly illuminate the image capturing section 19. In this state, when the work 9 is conveyed on the image capturing section 19, the imaged surface 9a of the work 9 is illuminated with the illumination light, and this illumination light is reflected by the imaged surface 9a. This reflected light passes through the cover glass 1, is reflected laterally by the mirror 3, and is imaged onto the line sensor 6 by the imaging optical system 5. The line sensor 6 outputs one line at a time as an image signal of the workpiece 9 in response to the reflected light.

This image signal is input to an image processing device (not shown),
It is used for predetermined image processing such as determining whether the work is correct or not, and whether it is good or bad.

It is desirable that the amount of light emitted by the light sources 4, 4 is controlled according to the output level of the line sensor 6. Further, even when the reflectance of the imaged surface 9a differs depending on the material of the workpiece 9, it is desirable to control the amount of light emitted from the light sources 4, 4 in the same manner. Therefore, it is desirable that the light sources 4, 4 are capable of adjusting the amount of light.

According to the above-mentioned embodiment, the image input device is extremely miniaturized by integrating and installing the image capture unit 19, the image input means 20, and the illumination means 18 in one case 15. reflecting members 11, 12, which reflect the illumination light toward the imaged surface 9a of the workpiece 9;
11.13 are arranged so as to surround the space between the illumination means 18 and the image capturing section 19, so that the imaged surface 9a
Soft illumination without unevenness can be obtained over the entire range, the irregularities and patterns on the imaged surface 9a of the workpiece 9 can be clearly highlighted, and the image signal can be accurately obtained by the image input means 20.

The mounting angle of the reflecting plates 12.13 is not particularly limited, but the center line of the illumination light reflected by these reflecting plates 12.13 is 40' to 50' with respect to the imaged surface 9a.
It is desirable to set the mounting at an angle that will result in an incident angle of Even in this case, since the illumination light can be reflected toward the image capture unit 19 from both ends of the row of light sources 4, the same effects as in the above embodiment can be achieved.

In addition, as shown in FIG. 7, light sources 25 and 27 having the same wavelength as the light source 4 are installed in the image capturing unit 1 in place of the reflectors 12 and 13.
9, and the illumination light may be irradiated onto the image capturing section 19 through the respective diffusers 26 and 28. This further improves the effect of ring lighting.

In each of the embodiments described above, the light source 4 is a directional light source whose output surface has the function of a condensing lens, and the directional light source 4 is combined with the diffuser plate 2, but an omnidirectional light source is used. Alternatively, a combination of an omnidirectional light source and a cylindrical lens that collects illumination light from the light source may be used.

Furthermore, the mirror 1 as a reflecting member in the above embodiment
0.10 is a flat mirror, but instead of this, a mirror with a concave reflecting surface may be used.

Note that, instead of the line sensor 6 in the illustrated embodiment, an image sensor capable of inputting a two-dimensional image signal may be used as the image input means.

(Effects of the Invention) According to the present invention, in an image input device having an image capture section, an image input means, and an illumination means, a reflecting member that reflects illumination light from the illumination means toward an imaged surface of a workpiece is provided. Because it is arranged to surround the space between the illumination means and the image capture unit, it is possible to improve the illuminance of the imaged surface, and to obtain soft illumination without unevenness over the entire range of the imaged surface, making it possible to The unevenness and pattern of the imaged surface can be clearly highlighted, and the image signal thereof can be accurately obtained by the image input means.

[Brief explanation of the drawing]

FIG. 1 is an external plan view showing an embodiment of the image input device according to the present invention, FIG. 2 is a cross-sectional front view of the same embodiment, FIG. 3 is a cross-sectional plan view of the same embodiment, and FIG. 4 is an implementation of the same. FIG. 5 is a cross-sectional side view of the example, and FIG. 5 is a plan view showing how the workpiece is illuminated by the reflecting member of the above embodiment. FIG. FIG. 7 is a cross-sectional side view showing still another embodiment of the image input device according to the present invention, FIG. 8 is a cross-sectional plan view showing an example of a conventional image input device, and FIG. 9 is a cross-sectional view of the same as above. FIG. 10 is a front view, FIG. 10 is a cross-sectional side view of the same, and FIG. 11 is a plan view showing how a workpiece is illuminated by the conventional image input device. 9... Workpiece, 9a... Imaged surface, 18...
- Illumination means, 19-:... Image capture unit, 20-
...Image input means, 11, 12, 13...Reflecting member, 10 Mirror as a reflecting member.

Claims (1)

[Claims] an image capture unit that captures an image of the imaged surface of the work; an image input unit that inputs the image of the imaged surface of the work;
In an image input device comprising an illumination means installed between the image capturing section and the image input means and illuminating the imaged surface of the workpiece, illumination light from the illumination means is reflected toward the imaged surface of the workpiece. An image input device characterized in that a reflecting member is arranged to surround a space between an illumination means and an image capturing section.