JPH1051595A - Image processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably pick up an image of an object at a low cost with high accuracy in the image processing system used for checking in the manufacturing process. SOLUTION: A printed circuit board 2, placed on a check board 1, is covered by a light shield means 5 having a light collection section to allow a leaked light to be made incident partly, the leaked light via the light collection section is reflected irregularly in the inner face of the light shield means to light the printed circuit board 2, a CCD video camera 3 being a photoelectric converter is used to pick up an image and its image output is processed by a check discrimination device 4 which is an image-processing unit so as to obtain the product checking system which is a stable and inexpensive image processing system having high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing system for processing an image captured by a camera. More specifically, the present invention relates to an image processing system used for inspecting an inspected product in a manufacturing process.

[0002]

2. Description of the Related Art Conventionally, in the inspection of a manufactured product in a manufacturing process,
The object to be inspected illuminated by the ambient illumination means and the illumination means dedicated to the inspection is photographed by an optical-electrical signal converter, for example, a CCD camera, and the image output from the camera is determined by an image processing apparatus, which is an inspection judgment. The data was input to the device to determine good and defective products.

FIG. 3 shows a conventional configuration example. In FIG. 3, a printed board 12 to be inspected is arranged on an inspection table 11, and a printed circuit board 12 illuminated by an ambient illumination unit (not shown) and an illumination unit 13 dedicated to the inspection is attached to a CCD camera 14. The image output from the CCD camera 14 is input to an inspection determination device 15 which is an image processing device.
The quality of the solder printing on the printed board 12 is determined.

[0004]

However, according to this conventional technique, the illumination environment of the inspection place, which is ambient light, the illumination method dedicated to the inspection object, and the illuminance strongly influence the inspection result, so that the inspection can be performed stably and accurately. It is difficult to find the lighting method and illuminance to be used and to maintain them. In addition, a special camera dedicated to inspection, a high-luminance dedicated lighting device, and a large power for lighting are required, so that the image processing system and its maintenance are expensive.

The present invention solves such problems, and solves the difficulty and instability of maintenance and management of a conventional image processing system for illuminating an object to be inspected in a manufacturing process by a dedicated illumination means. It is an object to reduce the price of this image processing system and the cost for its maintenance.

[0006]

In order to solve this problem, an image processing system according to the present invention has a lighting unit for omitting a dedicated illuminating means for an object to be inspected and allowing leakage light to enter, but has an ambient light. The inspection object is placed in the light shielding means for shielding most of the light, and the inspection object illuminated with the irregular reflection light in the light shielding means due to the leakage light of the ambient light can be easily obtained on the market at a low cost as a surveillance camera. , With a high sensitivity camera having a low minimum subject illuminance.

Thus, while being highly accurate and stable,
An inexpensive image processing system is obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention provides a subject, a light-to-electric signal converter for photographing the subject, a cover for covering the subject, and a light input to the light-to-electric converter. A light-shielding unit having a built-in portion, a light-receiving unit provided on the light-shielding unit, for illuminating the subject with ambient light as leak light, and an image output from the light-electric converter as an input. An image processing system configured with an image processing apparatus that processes the image of the subject, and a highly accurate, stable, and inexpensive image processing system can be obtained.

According to a second aspect of the present invention, there is provided an image processing system according to the first aspect, wherein the daylighting unit is provided on a surface facing a surface on which a subject is placed. Is obtained.

According to a third aspect of the present invention, the subject of the first aspect is an image processing system which is a product to be inspected in a manufacturing process, and a highly accurate, stable and inexpensive image processing system can be obtained. .

An embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 shows the configuration of an image processing system according to the present invention. In FIG. 1, a printed circuit board 2 which is an inspection object placed on an inspection table 1 such as a belt conveyor.
And an optical-electrical signal converter C for photographing the printed circuit board 2
Inspection and determination device 4 which is an image processing device to which the image output of CD video camera 3 is input, and other 5 except for the lower surface which is mounted with CCD video camera 3 and faces printed surface 2 and becomes a lighting section The light shielding means 5 is made of a light shielding material such as an iron plate. Daylighting part 6 of light shielding means 5
The ambient light leaked from the light source is irregularly reflected on the inner surface of the light shielding means, and uniformly illuminates the printed board 2 with low illuminance.

FIG. 2 shows a test pattern of the printed circuit board 2 for judging the inspection accuracy, that is, a printed circuit board 2 having m × n = N inspection points arranged in a plane at equal intervals vertically and horizontally by a CCD video camera. 3 and, based on the output, an inspection determination device 4
Is a distribution diagram in which the number N of inspection points having the same brightness is plotted on the vertical axis and the brightness L of the inspection point is plotted on the horizontal axis.

The curve A in FIG. 2 is the brightness distribution data of N inspection points on the printed circuit board 12 in the conventional configuration shown in FIG. 3 and is widely and flatly dispersed in the brighter direction with the brightness LA as the center. This indicates that the brightness variation of N pieces of the entire inspection point is large and the inspection accuracy is low.

The curve B in FIG. 2 is distribution data of brightness L obtained by photographing N inspection points on the printed circuit board 2 in the configuration of the present invention shown in FIG. (LA
> LB), the distribution is narrower and higher with less variance in the darker direction, indicating that there is little variation among the N inspection points and the inspection accuracy is high.

In the conventional method, the interior illumination and its irregularly reflected light and the illumination for the inspection object are combined to provide illumination for the inspection object. Variations and fluctuations in the indoor illumination and the illumination for the inspection object directly affect the inspection result. Was. In the present invention, the direct light by the indoor lighting is shielded by the light shielding means, and relatively stable leakage light is incident from the lower surface which is a lighting part of the light shielding means,
By illuminating the object to be inspected with the irregularly reflected light of the leaked light on the inner surface of the light shielding means, the illumination of the object to be inspected is uniform but stable even though it is dark.

Although the present invention has been described as an improved example of an image processing system for the purpose of inspection in a manufacturing process, the present invention is not limited to this, and is generally applied to a system for photographing a subject and performing image processing. For those skilled in the art,
Easy.

Further, the position of the daylighting section provided in the light shielding means of the present invention is not limited to the surface facing the inspection object.

[0019]

As described above, according to the present invention, the illuminating means dedicated to the subject can be omitted, the camera for photographing does not need a special one, the simple light shielding means, the stable and high inspection accuracy can be obtained. Thus, an inexpensive image processing system is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of an image processing system of the present invention.

FIG. 2 is a brightness distribution diagram of each point on a printed circuit board having a test pattern diagram.

FIG. 3 is a configuration diagram of a conventional image processing system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inspection table 2 Printed circuit board 3 CCD video camera 4 Inspection determination device 5 Light shielding means 6 Lighting part

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location H05K 3/34 512 G06F 15/64 D

Claims (3)

[Claims] A light-to-electric signal converter for photographing the object; a light-shielding means for covering the object and incorporating a light input portion of the light-to-electrical converter; and a light-shielding means. A lighting unit for illuminating the subject with ambient light as leakage light; and an image processing device that processes an image of the subject that has been taken by using an image output of the light-to-electric converter as an input. Image processing system. 2. An image processing system according to claim 1, wherein the daylighting unit is provided on a surface facing the surface on which the subject is placed. 3. An image processing system according to claim 1, wherein the subject is an object to be inspected in a manufacturing process.