JPH11135999A - Method and device for recognizing component for surface mounting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make components to be recognized more quickly, by improving the arithmetic processing speed for component recognition. SOLUTION: A two-dimensional data indicating the half peripheral contour of a component 29 sucked by a nozzle 21 of a suction head are obtained by projecting laser beam L from a range finding sensor 30 upon the component 29 from one side and, at the same time, scanning the component 29 with the laser beam L in a scanning direction which is set perpendicular to the center axis of the nozzle 21. The central position of the component 29 is found based on the two-dimensional data and the configuration feature of the component 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an optical distance measuring means arranged at a predetermined distance from a suction head, and determines the position of a component based on the detection of the distance to the component being sucked by the suction head. The present invention relates to a component recognition method and device for a surface mounter for recognition.

[0002]

2. Description of the Related Art Conventionally, a print head in which a suction head having a nozzle is mounted on a movable head unit and a small electronic component such as an IC is sucked and positioned from a tape feeder or the like of a component supply unit. 2. Description of the Related Art Surface mounters which are transferred onto a substrate and mounted at predetermined positions on a printed circuit board are generally known.

[0003] In this type of surface mounter, a component may be sucked in a state where the center of the component is displaced from the nozzle. Therefore, usually, the component recognition device provided on the suction head is used to pick up the component with respect to the nozzle. The suction position is detected, and the amount of movement of the suction head is corrected based on the detection result, and the component is mounted on the printed circuit board.

As such a component recognition device, for example,
An apparatus disclosed in Japanese Patent Publication No. 7-112118 is known.

This device has an optical distance measuring sensor having a light irradiating portion and a light receiving portion, and measures the distance between the component and the sensor while rotating the sucked component once around the nozzle axis. , Based on the measurement result.

[0006]

The recognition of a component by the above-described component recognition apparatus is usually performed after the component is mounted by the nozzle of the suction head and before the component is suctioned. It is preferable to be able to quickly recognize the component position in order to increase the mounting efficiency.

However, in the conventional component recognition apparatus disclosed in the above-mentioned publication, the component is rotated once when detecting the distance, and the distance is measured over the entire circumference of the component during the detection to recognize the position of the component. However, it takes a long time to perform an arithmetic process in recognition, and there is room for improvement in increasing the component position recognition speed.

[0008] Further, since the distance is measured while rotating the component, there is a concern that the component may be displaced by vibration due to vibration or the like, and it is desired to solve the problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a component recognition method and apparatus for a surface mounter capable of increasing the processing speed in component recognition and performing component recognition more quickly. It is intended to provide.

[0010]

In order to achieve the above object, the present invention provides an optical distance measuring device having a light irradiating section and a light receiving section, which is arranged at a predetermined distance from a nozzle of a suction head, In a method of measuring a distance from the optical distance measuring means to a component sucked by a nozzle and obtaining a component suction position by a suction head based on the measurement data, the one side of the component is kept stationary While irradiating the irradiation light of the optical distance measuring means from the above, the irradiation light is scanned in the scanning direction orthogonal to the central axis of the nozzle to obtain two-dimensional data representing the outline of the component, and the component is determined based on the two-dimensional data. The suction position is obtained.

According to this method, two-dimensional data indicating the outline of the component is obtained, so that the component suction position can be obtained based on this data and the shape characteristic portion of the component. In addition, in this method, since the irradiation light is only scanned in the scanning direction orthogonal to the nozzle center axis, it is possible to recognize the component suction position by measuring the distance of a half of the component or a smaller portion. For this reason, the number of collected data is greatly reduced as compared with the conventional method of measuring the distance around the entire part.

In this method, the position of two sides of the component is detected by detecting three inflection points corresponding to the corners of the component in the two-dimensional data, and the component suction position is determined based on the position of each side. If the target component is a rectangular component, it is possible to determine the suction position.

According to another aspect of the present invention, there is provided an optical distance measuring device including a light irradiation unit and a light receiving unit.
An apparatus which is arranged at a predetermined distance from a nozzle of a suction head, measures a distance from the optical distance measuring means to a component sucked by the nozzle, and obtains a component suction position of the suction head based on the measurement data. Scanning means for scanning the irradiation light of the optical distance measuring means in a scanning direction orthogonal to the central axis; and suction means for scanning the irradiation light in the scanning direction with the parts adsorbed by the nozzles stationary. It comprises a control means for controlling the head and the scanning means, and a calculation means for obtaining a component suction position based on the obtained data measured by the optical distance measuring means.

According to this apparatus, the irradiation light of the optical distance measuring means is scanned in the scanning direction based on the control of the scanning means by the control means, and the component pickup position is calculated by the calculating means based on the measurement data obtained thereby. Is required. This implements the method of claim 1.

The scanning means may comprise a movable mechanism for moving or swinging the optical distance measuring means so that the irradiation light is irradiated in the scanning direction, or a mirror for reflecting the irradiation light. And a swing mechanism for swinging the mirror. If you do this,
First, in the former, the scanning of the component is performed by the irradiation light in accordance with the movement or swing of the optical distance measuring means itself, and in the latter, the optical distance measuring means itself is fixedly arranged and swings the mirror. Scanning of the component by the irradiation light is performed accordingly.

[0016]

Embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show an example of a surface mounter according to the present invention. As shown in FIG. 1, a conveyor 2 for transporting a printed board is disposed on a base 1 of a surface mounter (hereinafter, abbreviated as a mounter), and a printed board 3 is transported on the conveyor 2. Is stopped at the mounting work position. On the front and rear sides of the conveyor 2, there are provided component supply units 4 each composed of a plurality of rows of tape feeders 4a and the like.

Above the base 1, a head unit 5 for mounting components is mounted.
Can move in the X-axis direction (the direction of the conveyor 2) and the Y-axis direction (the direction orthogonal to the X-axis on a horizontal plane).

That is, the base 1 is provided with a pair of fixed rails 7 extending in the Y-axis direction and a ball screw shaft 8 driven to rotate by a Y-axis servomotor 9. A head unit support member 11 is arranged, and a nut portion 12 provided on the support member 11 is screwed to the ball screw shaft 8. A guide member 13 extending in the X-axis direction and a ball screw shaft 14 driven by an X-axis servomotor 15 are disposed on the support member 11 so that the head unit 5 can move on the guide member 13. A nut portion (not shown) provided in the head unit 5 is screwed to the ball screw shaft 14. The ball screw shaft 8 is rotated by the operation of the Y-axis servo motor 9 to move the support member 11 in the Y-axis direction, and the ball screw shaft 14 is rotated by the operation of the X-axis servo motor 15, thereby causing the head unit to rotate. 5 moves in the X-axis direction with respect to the support member 11. The Y-axis servomotor 9 and the X-axis servomotor 15 each have an encoder 1 for detecting a drive position.
0 and 16 are provided.

The head unit 5 is provided with a suction head 20. This suction head 20
The head unit 5 can move up and down and rotate with respect to the frame. Although not shown in detail, a vertical drive unit using a Z-axis servo motor 22 as a driving source and a rotation unit using an R-axis servo motor 24 as a driving source It is designed to be driven by driving means. At the lower end of the suction head 20, a component suction nozzle 21 is provided. At the time of component suction, a negative pressure is supplied to the nozzle 21 from negative pressure supply means (not shown), and the component is suctioned by the negative pressure. It is designed to be adsorbed.

Further, below the head unit 5, a distance measuring sensor 30 (optical distance measuring means) for detecting the suction state of the component sucked by the nozzle 21 is provided.

The distance measuring sensor 30 is provided with a laser beam irradiating section and a light receiving section on the upper and lower sides, and measures a distance to an object by the principle of triangular ranging while scanning a part one-dimensionally with the laser beam. This is a so-called laser scanning sensor that is fixed to the frame of the head unit 5 at a predetermined distance from the nozzle 21.

Although illustration is omitted for the distance measuring sensor 30,
A laser generating source, a mirror that reflects the laser light generated here and irradiates the object through the irradiating unit, an oscillating driving mechanism that oscillates the mirror, for example, a motor as a driving source, It incorporates a position detection element that receives reflected light incident through the unit, and various lenses for projecting and receiving light, and reflects the laser light generated by the laser source with a mirror to an object. Irradiation is performed, and the reflected light reflected by the object is received by the position detection element. By oscillating the mirror by the operation of the oscillating drive mechanism, the irradiation light of the laser light is changed to scan one-dimensionally over a predetermined range including the component.

As shown in FIG. 3, the distance measuring sensor 30 outputs the laser beam L from one side in the X-axis direction to the other side.
And the laser light L is emitted to the side surface of the component 29 when the suction component 29 is placed at the predetermined recognition height. Then, by the operation of the swing drive mechanism,
The laser beam L is scanned in the Y-axis direction.

FIG. 4 is a block diagram showing a schematic configuration of a control system in the mounting machine. In this figure, a control device mounted on a mounting machine includes an axis control device 41 for controlling the driving of various rotary shafts such as the above-described servomotors, and a detection device 42 for receiving a signal from the distance measurement sensor 30 as a detection unit.
And a higher-level controller 43 for controlling them collectively.

The axis control device 41 includes the suction head 20.
Axis rotation control means 44 for controlling rotation by controlling the R-axis servomotor 24;
The shaft servomotor 22 includes a shaft height control unit 45 that controls elevation and lowering, and a suction control unit 46 that controls suction of components by controlling the supply of negative pressure to the nozzle 21. Means (not shown) for controlling the head unit 5 in the X and Y directions by controlling the motor 9 and the X-axis servo motor 15 are included.

The detecting device 42 includes a scanning control unit 47, a shape detecting unit 48, a storage unit 49, and a positioning calculating unit 50.

The scanning control means 47 operates the distance measuring sensor 3 so as to scan the component with a laser beam when recognizing the component.
0 is controlled. Further, the shape detecting means 48 detects a part of the contour of the component based on the measurement data of the distance measuring sensor 30 and stores it in the storage unit 49. Then, the positioning calculation means 50 calculates the component suction position based on the outline of the component and the characteristic feature of the component.

Next, the detection device 42 and the axis control device 4
1 will be described based on the flowchart of FIG. 5 with reference to FIGS. 6 to 8.

First, when a component is sucked from the component supply unit 4 by the nozzle 21 of the suction head 20, the suction component 29 is arranged at a predetermined recognition height position by lifting and lowering and rotating the suction head 20. (Step S1).

Then, a laser beam L is emitted from the distance measuring sensor 30, and the laser beam L is scanned in the Y-axis direction.

For example, in the case where the component 29 (rectangular component) is attracted as shown in FIG. 6, when the laser beam L is scanned in this manner, the two sides 29a, 29 located on the distance measuring sensor side.
The laser beam L is reflected at b, and the laser beam L transmits through the component 29 in other portions. Therefore, the side 2 of the component 29
The distance between each of the positions 9a and 29b and the distance measuring sensor 30 is measured, and the two-dimensional data as shown in FIG.
A contour corresponding to the portion extending over a and 29b is obtained. Then, from the two-dimensional data, three inflection points Ta, T
b, Tc, that is, the corner of the component 29 is detected (step S2).

If the three inflection points Ta, Tb, and Tc cannot be detected, the flow goes to step S4 to rotate the suction head 20 by 90 degrees, and then goes to step S1 to move the laser beam L Scans the component 29 again. In addition,
As a specific example in which the inflection point cannot be detected, for example, as shown in FIG. 8A, the inclination of the component with respect to the laser beam irradiation direction is small, and the inflection portion (the inflection point Ta) becomes a straight line. When the distance is close or when the inflection point (inflection point Ta) is
May be out of the measurement range.

In step S2, the inflection points Ta, Tb,
When Tc is detected, the sides 29a, 29
The positions of the two sides L ₁ and L ₂ corresponding to b are detected, and the positions of the midpoints P ₁ and P ₂ of the sides L ₁ and L ₂ are obtained. Thus the intersection of a line segment parallel to the sides L ₁ through parallel line segments and the middle point P ₂ on the side L ₂ through the midpoint P _1, that is, the center position Oa of the component 29 is determined.

Then, the center position Oa of the obtained part 29 is obtained.
Then, the component suction position is obtained from the nozzle center position Ob which is known data. At this time, if the component suction position is shifted, that is, if the center position Oa of the component 29 and the nozzle center position Ob are shifted, the shift amount is obtained.
Further, based on the angle formed between the two sides L ₁ and L ₂ and a line segment parallel to the X-axis or the Y-axis, the shift amount of the component 29 around the nozzle axis is obtained (step S3). Note that the nozzle center position Ob may be a designed theoretical position of the distance measurement sensor 30 and the nozzle 21. Alternatively, the distance from the nozzle 21 may be measured by the distance measurement sensor 30 and the nozzle center position may be obtained based on the two-dimensional shape obtained from the distance measurement sensor 30 in the same manner as in the recognition of the component suction position.

When the component 29 is mounted on the printed circuit board 3, the mounting position is corrected in accordance with the amount of displacement determined as described above.

In the mounting machine described above, the component supply unit 4 uses the suction head 20 of the head unit 5 to move the component 2.
After the nozzle 9 is sucked, a component recognition process as shown in the flowchart is performed based on the scanning by the distance measuring sensor 30 provided in the head unit 5. In this case, since the laser beam L is scanned in the Y-axis direction while the component 29 is stationary, the distance measurement is performed for a half circumference of the component. In other words, the component suction position can be recognized based on the measurement data for a half circle of the component. For this reason, the number of data required for recognizing a component suction position is greatly reduced as compared with a conventional device of this type that measures a distance over the entire circumference while rotating a component. Therefore, the operation processing speed in recognizing the component suction position can be effectively increased, whereby the component suction position can be more quickly recognized.

Further, in the conventional apparatus, since the distance is measured while rotating the parts, there is a concern that the suction may be deviated due to rotational inertia or vibration. To suppress this, it is necessary to perform processing such as rotation at a low speed. However, according to the mounting machine described above, since the scanning by the laser light L is performed in a state where the component 29 is stationary, there is no fear of the slippage due to the vibration even if the scanning is performed at a high speed. Therefore, it is possible to more accurately recognize the component position in a short time.

In the mounting machine described above, a scanning means capable of scanning a laser beam, that is, a distance measuring sensor 30 (laser scanning sensor) incorporating a mirror and a swinging drive mechanism is used as the distance measuring sensor. For example, a distance measuring sensor which does not include such a mechanism may be used. In this case, as a scanning means, a mechanism for moving the distance measuring sensor itself in the Y-axis direction or a mechanism for swinging the distance measuring sensor itself around the Z-axis is provided so as to scan the laser beam. I just need.

In the above description, the method of recognizing the component suction position has been described using a case where a rectangular component 29 is used as an example. Of course, the recognition of a component having a shape other than a rectangle is performed. It is also possible to do. Also in this case, two-dimensional data indicating the component outline is obtained by distance measurement by the distance measurement sensor 30, and the component suction position may be obtained based on this data and the shape characteristic portion of the component.

[0041]

As described above, according to the present invention, two-dimensional data obtained by scanning the irradiation light of the optical distance measuring means in a scanning direction orthogonal to the center axis of the nozzle while the component is stationary. In other words, since the component suction position is determined from the shape characteristic of the contour of the part half circumference or less, the collected data is compared to the conventional method of measuring the distance over the entire circumference of the part. The number is greatly reduced. Therefore, the operation processing speed in recognizing the component suction position can be effectively increased, whereby the component suction position can be more quickly recognized.

In particular, when the component to be recognized is a rectangular component, three inflection points corresponding to the corners of the component are detected to determine the positions of the two sides of the component, and based on the positions of these two sides. If the component suction position is determined, the component suction position can be determined.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an example of a mounting machine provided with the apparatus of the present invention.

FIG. 2 is a schematic front view of the same.

FIG. 3 is a schematic plan view showing a relative arrangement of a distance measuring sensor and a suction component.

FIG. 4 is a block diagram showing a control system.

FIG. 5 is a flowchart illustrating a part recognition process.

FIG. 6 is a conceptual diagram illustrating the relationship between ranging and ranging data (two-dimensional data).

FIG. 7 is a diagram (ranging data) illustrating a procedure of component position recognition.

FIGS. 8A and 8B are diagrams (distance measurement data) showing an example in which an inflection point cannot be detected from the distance measurement data.

[Explanation of symbols]

 5 Head Unit 20 Suction Head 21 Nozzle 29 Parts 30 Distance Measurement Sensor 41 Axis Control Device 42 Detector 43 Upper Controller 44 Axis Rotation Control Means 45 Axis Height Control Means 46 Suction Control Means 47 Scan Control Means 48 Shape Detection Means 49 Storage Part 50 positioning calculation means

Claims (5)

[Claims] An optical distance measuring means having a light irradiating part and a light receiving part is arranged at a predetermined distance from a nozzle of a suction head, and a distance from the optical distance measuring means to a component sucked by the nozzle is provided. And measuring the position of the component by the suction head based on the measurement data. In the method, while irradiating the irradiation light of the optical distance measuring means from one side with the component stationary, the nozzle center is A component recognition method for a surface mounter, comprising: obtaining two-dimensional data representing a contour of a component by scanning the irradiation light in a scanning direction orthogonal to an axis; and obtaining a component suction position based on the two-dimensional data. . 2. The method according to claim 1, wherein three inflection points corresponding to component corners are detected in the two-dimensional data to detect the positions of two sides of the component, and to determine a component suction position based on the position of each side. 2. The method for recognizing a component of a surface mounter according to claim 1, wherein: 3. An optical distance measuring means having a light irradiating part and a light receiving part is disposed at a predetermined distance from a nozzle of a suction head, and a distance from the optical distance measuring means to a component sucked by the nozzle. A scanning means for scanning the irradiation light of the optical distance measuring means in a scanning direction orthogonal to a nozzle center axis, and a nozzle for measuring a component suction position by a suction head based on the measurement data. Control means for controlling the suction head and the scanning means to scan the irradiation light in the scanning direction in a state where the component sucked to the stationary state,
A component recognizing device for a surface mounter, comprising: arithmetic means for obtaining a component suction position based on measurement data obtained by the obtained optical distance measuring means. 4. The surface mount according to claim 3, wherein said scanning means comprises a movable mechanism for moving or swinging said optical distance measuring means so that irradiation light is emitted in said scanning direction. Machine parts recognition device. 5. The device according to claim 3, wherein said scanning means comprises a mirror for reflecting said irradiation light and a swing mechanism for swinging said mirror.