JP3680704B2 - Image recognition method for recognition mark in electronic component mounting apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image recognition method for a recognition mark in an electronic component mounting apparatus that recognizes an image of a recognition mark provided on a workpiece such as a substrate in the electronic component mounting apparatus.
[0002]
[Prior art]
In electronic component mounting devices such as screen printing devices that print cream solder on substrates and electronic component mounting devices that mount electronic components on substrates after cream solder printing, such as workpieces such as substrates, component supply units, nozzle stockers, etc. A method of detecting a recognition mark by image recognition is widely used for position detection. In this method, a recognition mark formed on a recognition target part is detected by performing image processing on imaging data obtained by imaging the recognition target part with a camera.
[0003]
In the image processing for detecting the recognition mark, the recognition mark is extracted based on the luminance difference between the recognition mark on the image and the surrounding background portion, and the shape and position of the recognition mark are detected from the extraction result. . For this reason, when imaging the region to be recognized, the recognition mark is configured so that the portion of the recognition mark can be clearly separated from the surroundings on the image, and the imaging conditions and illumination conditions suitable for this configuration are adopted. There is a need to.
[0004]
By the way, as a recognition mark, a seal-like one formed by printing a recognition mark on a thin film is used. This seal-like recognition mark has an advantage that it can be used as a recognition mark simply by sticking it to various recognition objects such as a substrate by preparing a general-purpose size and shape in advance.
[0005]
[Problems to be solved by the invention]
However, the conventional method using a seal-like recognition mark has the following problems in detecting the recognition mark. As a base material for the seal-like recognition mark, a silver thin film is generally used, and a black dot printed on the thin film surface is used as the recognition mark. That is, a black spot on the silver background color is captured as a recognition target. However, this seal-like recognition mark can clearly distinguish black spots when viewed with the naked eye, but when captured by a camera, the black spots cannot be clearly distinguished from the background on the image, and the recognition mark image recognition is not possible. It was difficult.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a recognition mark image recognition method in an electronic component mounting apparatus that can satisfactorily recognize a recognition mark on an image.
[0007]
[Means for Solving the Problems]
The image recognition method of the recognition mark in the electronic component mounting apparatus according to claim 1, wherein the recognition mark formed on the recognition seal is imaged from the recognition target portion by imaging the recognition sticker attached to the recognition target portion of the workpiece. An image recognition method for a recognition mark in an electronic component mounting apparatus that is extracted and recognized, wherein the recognition sticker has the same color as the colored illumination light emitted from the illumination means for illuminating the recognition target part during imaging . The recognition mark was formed on the thin film .
[0008]
The recognition mark image recognition method in the electronic component mounting apparatus according to claim 2 is the recognition mark image recognition method in the electronic component mounting apparatus according to claim 1, wherein the colored illumination light of the illumination means is a red LED. And the thin film is red.
[0009]
The present invention, therefore by forming a recognition mark in recognition seal consisting of colored illumination light and the main colors of the thin film of the illumination means for illuminating the recognition target region during the imaging, the reflected light from the thin film is a background portion By increasing the amount of light and clarifying the contrast of the brightness difference with the recognition mark, good recognition can be performed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an image recognition apparatus according to an embodiment of the present invention, FIG. 2A is a plan view of a substrate that is an image recognition target according to an embodiment of the present invention, and FIG. FIG. 3 is an explanatory view of a recognition mark image recognition method according to an embodiment of the present invention.
[0011]
First, an image recognition apparatus will be described with reference to FIG. This image recognition apparatus is incorporated in an electronic component mounting apparatus such as an electronic component mounting apparatus or a cream solder printing apparatus, and is used for detecting the position of a mounting target board. In FIG. 1, a substrate holding unit 2 holds a substrate 1 for mounting an electronic component, which is a workpiece. The substrate holder 2 is moved and positioned by the positioning table 3 in the horizontal direction.
[0012]
As shown in FIG. 2A, a recognition seal 4 that is a seal-like recognition mark is attached to both diagonal positions that are recognition target portions of the substrate 1. As shown in FIG. 2B, the recognition sticker 4 is obtained by printing a black recognition point 4b (recognition mark) on a circular thin film 4a. Here, the upper surface of the thin film 4a is coated in red, and the recognition seal 4 has a configuration in which a black recognition point is formed in a red background color.
[0013]
Above the substrate holding unit 2, a camera 5 having an illumination device 6 (illuminating means) is disposed. The substrate 1 held by driving the substrate holding unit 2 by a driving mechanism (not shown) moves horizontally, and the recognition seal 4 attached to the substrate 1 can be positioned below the camera 5. And the recognition sticker 4 can be imaged by imaging the recognition object site | part of the board | substrate 1 with the camera 5 in the state which turned on the illuminating device 6. FIG. Here, the illuminating device 6 includes a large number of red LEDs as a light source. When the illuminating device 6 is turned on, the upper surface of the lower recognition seal 4 is irradiated with red illumination light.
[0014]
The camera 5 is connected to the A / D conversion unit 10. The A / D conversion unit 10 performs A / D conversion on the image data captured by the camera 5. The A / D converted image data is stored in the image storage unit 11. The illumination drive unit 12 drives the illumination device 6 when the camera 5 captures an image. The table driving unit 13 drives the positioning table 3 that moves the substrate holding unit 2.
[0015]
The image recognition unit 15 performs image processing on the image data stored in the image storage unit 11 to extract the recognition point 4b on the upper surface of the thin film 4a of the recognition sticker 4, that is, the black point in the red background color. Detect position. The recognition result storage unit 16 stores a position detected as a result of position recognition. CPU14 controls each said part of an image recognition apparatus.
[0016]
This image recognition apparatus is configured as described above. Hereinafter, extraction of a recognition mark using the recognition seal 4 performed by the image recognition apparatus will be described. First, when the substrate 1 to which the recognition seal 4 is attached is held by the substrate holding unit 2, the recognition seal 4 is aligned below the camera 5. Next, the illuminating device 6 is turned on to cause the red LED 6a to emit light, and the imaging target portion of the substrate 1 is irradiated with red illumination light (arrow a). As a result, the recognition sticker 4 is illuminated with red light, and reflected light from the surface of the recognition sticker 4 enters the camera 5, whereby the recognition sticker 4 is imaged.
[0017]
In this imaging, as shown in FIG. 3A, the reflected light (arrow b) from the black recognition point 4b is slight, whereas the reflection from the thin film 4a which is the background color portion of the recognition point 4b. As for the light (arrow c), the surface of the thin film 4a is red in the same color as the red illumination light, so the amount of reflected light from the thin film 4a is compared with the reflected light from the black recognition point 4b. The reflected light is reflected with a clear light quantity ratio from the background portion and the recognition point.
[0018]
Thereby, on the image 20 obtained by capturing this reflected light with the camera 5, as shown in FIG. 3B, the brightness of the portion corresponding to the recognition point 4b and the portion corresponding to the thin film 4a which is the background portion. The contrast appears clearly, and the recognition point 4b can be correctly extracted to obtain a good position recognition result.
[0019]
The effect of using the same color as the colored illumination light as the background color in the recognition mark as described above has been clearly confirmed by actual imaging. That is, in the result of comparing the image obtained by imaging the conventional recognition sticker printed with a black dot on the silver thin film and the black dot on the red thin film shown in this embodiment under the same conditions, By using the recognition sticker of the form, it is possible to stably obtain much better recognition accuracy.
[0020]
In the above embodiment, an example in which a red LED is used as a light source for illumination is shown, but a colored light source other than this may be used. In this case, the same color corresponding to the colored illumination light of the light source to be used is used as the background color.
[0021]
Furthermore, in the above-described embodiment, an example in which a recognition mark is used for detecting the position of the board is shown. However, the recognition target part is not limited to a workpiece such as a board. For example, electronic component mounting such as a component supply unit or a nozzle stocker You may use for the position recognition of the units which need to detect a position individually in an apparatus.
[0022]
【The invention's effect】
The present invention, therefore by forming a recognition mark in recognition seal consisting of colored illumination light and the main colors of the thin film of the illumination means for illuminating the recognition target region during the imaging, the reflected light from the thin film is a background portion By increasing the amount of light and clarifying the contrast of the brightness difference with the recognition mark, good recognition can be performed. The recognition target part is not limited to a workpiece such as a substrate, but can be applied to position recognition of units that need to individually detect positions in an electronic component mounting apparatus such as a component supply unit and a nozzle stocker.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an image recognition apparatus according to an embodiment of the present invention. FIG. 2A is a plan view of a substrate that is an image recognition target according to an embodiment of the present invention. FIG. 3 is a plan view of a seal-like recognition mark according to an embodiment.
1 Substrate 4 Recognition seal 4a Thin film 4b Recognition point 5 Camera 6 Illumination device 6a Red LED

Claims (2)

This is an image recognition method for a recognition mark in an electronic component mounting apparatus that extracts and recognizes a recognition mark formed on a recognition sticker by imaging the recognition sticker attached to the recognition target part of the workpiece. The recognition sticker is made of a thin film having the same color as the colored illumination light emitted from the illumination means for illuminating the recognition target part during imaging, and the recognition mark is formed on the thin film. An image recognition method for a recognition mark in a component mounting apparatus. 2. A method for recognizing an image of a recognition mark in an electronic component mounting apparatus according to claim 1, wherein the colored illumination light of the illumination means is red light using a red LED as a light source, and the thin film is red.

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