JP3263538B2 - Recognition device and nozzle position recognition method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle for recognizing a positional shift of a component held by a nozzle with respect to the nozzle based on a screen imaged by an image pickup device and for recognizing the positional shift. And a recognition method for recognizing the component holding surface of the nozzle.

[0002]

2. Description of the Related Art The prior art of this kind of recognition apparatus will be described with reference to FIGS. When mounting an electronic component on a printed circuit board by suction with a suction nozzle, detection of a positional shift of the component with respect to the position of the nozzle is performed based on a screen imaged by an imaging camera. Then, the component displacement is corrected and the component is mounted at a predetermined position on the printed circuit board. The reference position for performing this recognition is the center position when the component holding surface of the nozzle has a substantially circular shape, but the reference position may be shifted due to the nozzle mounting method or a subsequent temperature change. It is necessary to recognize the reference position of the nozzle from the imaging screen of the imaging camera.

In order to determine the center position which is the reference position of the image of the circular component holding surface 80 as shown in FIG.
A plurality of elongated detection windows 81 are set in the screen in parallel in the up-down direction.
As shown in FIG. 8 or FIG. 9, the change in the brightness along the longitudinal direction of FIG. 1 was projected, and edges were detected by a graph obtained by differentiating the projected data along the same direction. Similarly, a window is set in a direction perpendicular to the window 81 in FIG. 7, edges are detected in the horizontal direction, and the center of the circle is calculated from the position of each edge.

[0004]

However, in the above-mentioned prior art, as shown in FIG. 7, in a window 81 near the center of the component holding surface 80, the change in the projected brightness is abrupt as shown in FIG. The position of the edge is accurately obtained from the graph, but when it is farther from the center, as shown in FIG.
The change in the projected lightness is gradual, the position of the edge cannot be accurately determined from the differentiated graph, and the center position calculated based on this data has a disadvantage that an error occurs.

Accordingly, an object of the present invention is to accurately determine a reference position for component recognition of a nozzle holding a component.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a recognition apparatus for recognizing a positional shift of a component held by a nozzle with respect to the nozzle based on a screen imaged by the imaging apparatus.
Window setting means for radially setting a window for detecting the edge of the component holding surface image of the nozzle in the imaging screen of the imaging device; and a change in the brightness of the image along the longitudinal direction of the window. Edge detecting means for detecting an edge position, and recognizing the displacement based on an edge position for each window detected by the detecting means
It is provided with a calculation means for calculating a reference position in relation to the standard component holding face of the nozzle for.

According to another aspect of the present invention, there is provided a recognition apparatus for recognizing a positional shift of a component held by a nozzle with respect to the nozzle based on a screen imaged by an imaging device. Initial position detecting means for detecting a certain initial position, and window setting means for setting a window for detecting the edge of the component holding surface image of the nozzle radially around the initial position in the imaging screen of the imaging apparatus, Edge detecting means for detecting the edge position of the component holding surface from a change in the brightness of the image along the longitudinal direction of the window; and recognizing the displacement based on the edge position for each window detected by the edge detecting means. for
It is provided with a calculation means for calculating a reference position of the component holding face of the nozzle serving as a reference.

According to the present invention, there is provided a screen imaged by an image pick-up device, which shows a positional shift of a component held by the nozzle with respect to the nozzle.
In a nozzle position recognition method for base recognition, a window setting step of radially setting a window for detecting an edge of a component holding surface image of a nozzle in an imaging screen of the imaging apparatus, and in a longitudinal direction of the window. A detecting step of detecting an edge position of the component holding surface from a change in brightness of an image along the line, and a reference for recognizing the positional shift based on an edge position of each window detected in the detecting step.
And a calculation step of calculating a reference position of the component holding surface of the nozzle to be used .

[0009]

According to the first aspect of the present invention, the window setting means radially sets a window in the imaging screen of the imaging device, and the edge detection means detects the component based on a change in brightness of the image along the longitudinal direction of the window. The edge position of the surface is detected, and the calculating means calculates the reference position of the nozzle holding surface based on the edge position.

According to the second aspect of the present invention, the window setting means radially sets the window around the initial position in the component holding surface of the nozzle detected by the initial position detecting means in the imaging screen of the imaging device, Edge detecting means detects an edge position of the component holding surface from a change in brightness of the image along the longitudinal direction of the window, and calculating means calculates a reference position of the nozzle holding surface based on the edge position.

According to the third aspect of the present invention, a window is radially set in the image pickup screen of the image pickup device in the window setting step, and the component is determined based on a change in brightness of the image along the longitudinal direction of the window in the detection step. An edge position of the holding surface is detected, and a reference position of the nozzle holding surface is calculated based on the edge position in a calculation step.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 and 3, reference numeral 1 denotes a Y table which moves in the Y direction by rotation of a Y-axis motor 2, and 3 denotes a movement in the X direction on the Y table 1 by rotation of an X-axis motor 4. As a result, the printed circuit board 6 on which the chip-shaped electronic components 5 (hereinafter, referred to as chip components or components) are mounted is fixedly mounted on fixing means (not shown).

Reference numeral 7 denotes a supply table on which a number of component supply devices 8 for supplying the chip components 5 are provided. Reference numeral 9 denotes a supply stand drive motor. The supply stand 7 is guided by a linear guide 12 through a nut 11 fixed to the supply stand 7 by screwing the ball screw 10 by rotating the ball screw 10. Move in the direction. Reference numeral 13 denotes a rotary table which rotates intermittently. At the outer edge of the table 13, mounting heads 15 having a plurality of suction nozzles 14 are arranged at equal intervals in accordance with an intermittent pitch.

The suction station I is a stop position of the mounting head 15 where the suction nozzle 14 sucks and picks up the component 5 from the supply device 8 due to the intermittent rotation of the rotary table 13. 5 is adsorbed. 16 is a component 5 to which the suction nozzle 14 sucks.
This is an imaging camera as an imaging device for imaging the lower surface of the component 5 in a predetermined visual field range, and is provided in the recognition station II. The recognition processing device 24, which will be described later, performs recognition processing on the image screen and recognizes it.

Next mounting head 1 of recognition station II
The stop position of the position 5 is the angle correction station III, and the head rotation device 17 is moved by an angle amount in which the angle amount for correcting the angular position deviation of the chip component 5 based on the recognition result of the recognition device 24 is added to the predetermined angle amount. Is the mounting head 15
Is rotated in the θ direction. The θ direction is a direction that rotates around the axis of the nozzle 14.

The next stop position after the angle correction station III is the mounting station IV, and the component 5 to be sucked by the suction nozzle 14 of the station IV onto the substrate 6
Is mounted by lowering the mounting head 15. Reference numeral 20 denotes a vertically moving lifting rod, which is a swing lever 21 of the component supply device 8.
Then, the chip component 5 is supplied to the component suction position of the suction nozzle 14 by intermittently feeding a component storage tape (not shown) enclosing the chip component 5 at a predetermined interval according to the interval. Reference numeral 22 denotes a tape reel for winding the component storage tape (not shown).

Next, a control block of the electronic component automatic mounting apparatus will be described with reference to FIG. 25 is a CPU, R
According to the program stored in the OM 26, the RAM 27
Performs various controls relating to the mounting of the chip component 5 on the substrate 6 based on the various data stored in the. The CPU 2 has an interface 2
The Y-axis motor 2, the X-axis motor 4, the head rotating device 17 and the like are connected via a drive circuit 8 and a drive circuit 29 to control the drive.

The operation of the above configuration will be described below. First, the recognition of the chip component 5 by the nozzle 1
In order to recognize the positional deviation with respect to No. 4, the recognition of the center position, which is the reference position of each nozzle 14, is performed according to the flowchart of FIG. That is, for each head 15, the nozzle 14 to be imaged is rotated to a position where component suction should be performed. This rotation is performed from the mounting station IV to the suction station.
Although it is rotated by a head rotation device (not shown) provided between the stations I, it may be rotated by the head rotation device 17.

In this way, the mounting head 15 is moved to the recognition station II without sucking the component 5, and the imaging camera 16 images the nozzle 14. In this imaging, illumination is applied from above the nozzle 14 and the transmitted light is imaged, so that the lower end surface, which is the component holding surface of the nozzle 14, is imaged dark. Next, the recognition processing device 24 uses the brightness of the screen imaged by the camera 16 as an initial position detecting means, binarizes each pixel with a predetermined threshold value, and uses the binarized data by a blob analysis technique. To determine the center of gravity as the initial position of the image of the nozzle lower end surface. That is, the pixel value of the captured image is X
The projection is performed on the (Y) axis, and the sum of the product sum of each projection result and its X (Y) coordinate value divided by the total sum of the projection results is defined as the X (Y) gravity center position. Since the lower end surface of the nozzle 14 is substantially circular, the center of gravity is at the center, but the accuracy of the calculated position of the center of gravity is approximate.

Next, the recognition processing device 24 functions as a window setting means, and sets a plurality of detection windows 31 radially at equal angular intervals around the center of gravity obtained in the nozzle image 30 as shown in FIG. Next, the recognition processing device 24 functions as edge detection means, and edge detection is performed.

That is, the brightness, which is the multivalued data of each pixel, is projected from the position of the center of gravity along the detection window 31 toward the longitudinal direction of the window 31. Since the detection window 31 has a predetermined width, there are a plurality of pixels in a direction perpendicular to the longitudinal direction, and a graph along the longitudinal direction is projected as shown in FIG. 5 by adding the luminance of each pixel. It can be done.

Since the window 31 passes through the center of the nozzle image 30 at the position of the edge 32 of the window 31 in the nozzle image 30, the longitudinal direction of the window 31 with respect to the tangent indicated by the dotted line in FIG. Intersect at a substantially right angle, and the projected data suddenly changes from dark to bright as shown in FIG. 5, and when this projected graph is differentiated, the position of the edge 32 rises in a narrow range as shown in FIG. It can be obtained more accurately than a simple waveform. Similarly, in all the detection windows 31, the tangent line of the nozzle image 31 and the window 31 intersect at a substantially right angle, so that the position of the edge 32 can be accurately obtained in all the windows 31.

Next, based on the detected edge 32, the recognition processing device 24 functions as a calculating means, and performs position calculation for calculating the position of the center of gravity of the nozzle image 30. That is, three points are selected from the detected edge 32, the center of a circle having these three points on the circumference is calculated, and the average of the center positions of the circles calculated for a plurality of sets of three points to be selected is calculated. Calculate the center of gravity. The position of the calculated center of gravity becomes a reference position.
This result is output as a reference position and stored in the RAM 27.

If the reference position is obtained at three or more rotation positions of the head 15, the rotation center position of the head 15 can be obtained.
Should be memorized. Next, when the automatic operation of the apparatus is started, the chip component 5 is taken out of the component supply device 8 by the selected suction nozzle 14 in the mounting head 15, and
In the recognition station II due to the intermittent rotation of the rotary table 13, the imaging device 16 captures an image of the component 5.

Next, based on the image, a recognition processing device 24
Recognizes the displacement of the component 5 with respect to the aforementioned rotation center position. Next, the head 15 is moved to the angle correction station III.
Is reached, the head rotation device 17 adds an angular position shift based on the recognition result and rotates the amount of angle to be swung indicated by data (not shown) to perform angle positioning.

Next, the head 15 is mounted on the mounting station IV.
Is reached, the component 5 is mounted on the printed circuit board 6 at a position indicated by unillustrated data. At this time, XY
The bull 3 corrects a positional shift in which the nozzle 14 at a position eccentric from the rotation center position rotates due to the rotation of the head 15 at the positional shift in the XY direction recognized by the recognition processing device 24 and the position in the XY direction shifts. The CPU 25 rotates the X-axis motor 4 and the Y-axis motor 2 so as to move.

In this embodiment, the binarized image data is subjected to blob analysis in order to determine the position of the center of gravity as the initial position.
The position may be stored in the AM 27 and the position may be used as the initial position. In addition, as the initial position, the nozzle image 3
If the position falls within 0, the center of gravity may not be the center of gravity. In this case, the detection window 31 is set in accordance with the present embodiment with the center of gravity obtained as in the present embodiment as the initial position again, and the center of gravity is accurately determined. The position may be obtained.

Further, even if a position outside the nozzle image 30 is selected as the initial position instead of the position inside the nozzle image 30, it is determined that the initial position is a bright position as in the present embodiment. If the position where the color changes from light to dark is detected as an edge, and if there are three or more detected edges, the center of the circle is determined from the position of the edge and the detection window is radially provided again from the center to accurately perform the same operation. It is possible to determine the center of gravity of the nozzle image.

[0029]

As described above, according to the present invention, since the window for detecting the edge is set radially, the change in the brightness of the image at the time of detecting the edge is clear, and the position of the edge can be accurately detected. Therefore, an accurate reference position of the component holding surface of the nozzle can be obtained .

[Brief description of the drawings]

FIG. 1 is a diagram showing a detection window set for a captured image.

FIG. 2 is a plan view of the electronic component automatic mounting apparatus.

FIG. 3 is a side view of the electronic component automatic mounting apparatus.

FIG. 4 is a control block diagram of the electronic component automatic mounting apparatus.

FIG. 5 is a diagram illustrating edge detection.

FIG. 6 is a diagram showing a flowchart.

FIG. 7 is a diagram in which a detection window is set in the related art.

FIG. 8 is a diagram showing edge detection in the related art.

FIG. 9 is a diagram showing edge detection in the related art.

[Explanation of symbols]

 Reference Signs List 5 chip-shaped electronic component 14 suction nozzle 16 imaging camera (imaging device) 24 recognition processing device 30 nozzle image 31 detection window 32 edge

Claims (3)

(57) [Claims] An apparatus for recognizing a positional shift of a component held by a nozzle with respect to the nozzle based on a screen imaged by an imaging device, for detecting an edge of a component holding surface image of the nozzle. Window setting means for radially setting a window in an image pickup screen of the image pickup apparatus; edge detection means for detecting an edge position of a component holding surface from a change in brightness of an image along a longitudinal direction of the window; Based on the edge position for each window detected in
A recognition device, comprising: a calculation unit that calculates a reference position of a component holding surface of a nozzle as a reference for recognizing a positional shift . 2. A recognizing device for recognizing a positional shift of a component held by a nozzle with respect to the nozzle based on a screen imaged by an imaging device. Initial position detection means for detecting an initial position in the window, and a window setting means for radially setting a window for detecting an edge of the component holding surface image of the nozzle in the imaging screen of the imaging device radially around the initial position. Edge detecting means for detecting an edge position of the component holding surface from a change in brightness of an image along a longitudinal direction of the window, and recognizing the displacement based on an edge position for each window detected by the edge detecting means. A recognition unit provided with calculation means for calculating a reference position of a component holding surface of a nozzle serving as a reference for performing the calculation. 3. A position shift of a component held by a nozzle with respect to the nozzle is recognized based on a screen imaged by an imaging device.
A nozzle position recognizing method, a window setting step of radially setting a window for detecting an edge of a component holding surface image of a nozzle in an image capturing screen of the image capturing apparatus, and an image along a longitudinal direction of the window. A detection step of detecting an edge position of the component holding surface from a change in brightness;
Group to the edge position of each detected window in detection step
A calculating step of calculating a reference position of the component holding surface of the nozzle, which is a reference for recognizing the positional deviation, is provided.