JPH0683945A - Body recognizing device - Google Patents

Abstract

PURPOSE:To automatically and accurately perform operation for setting by previously setting the interval between the camera of the body recognizing device, provided on a component mounting device, etc., and a body whose image is to be picked up so that the image of the object body becomes excellent. CONSTITUTION:The body recognizing device which detects the position of a chip component 39, etc., from the image of the body, sucked by a suction nozzle 20, picked up by the camera 31 is equipped with an interval setting means which sets the interval between the component position and camera 31. This means detects the density distribution of the image while varying the interval between the body while setting the camera 31 and component opposite each other, and detects the interval where a sharp image is obtained on the basis of the detected distribution, thereby employing the detected interval as a set value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article recognition device which is provided in a component mounting device and used for detecting the position of a chip component.

[0002]

2. Description of the Related Art Conventionally, there has been known an article recognition apparatus which detects an image pickup object position by processing an image pickup object image picked up by an image pickup means such as a CCD camera by an image processing means ( See Japanese Patent Laid-Open No. 1-240987). Such an article recognition device is used, for example, in a component mounting device that mounts a chip component on a printed circuit board, for correcting the mounting position based on the detection of the position of the chip component.

That is, the above-mentioned component mounting apparatus uses a component mounting head unit having a suction nozzle to mount a chip component (electronic component) from a component supply unit such as a tape feeder.
The head unit and the printed circuit board are moved relative to each other in the X-axis direction and in the Y direction. In addition to being movable in the axial direction, the suction nozzle is movable in the Z-axis direction and rotatable, and a drive mechanism for moving and rotating in each direction is provided. In this component mounting device, since the position (center position and rotation angle) of the chip component varies when the chip component is sucked by the suction nozzle, the position of the chip component is detected and mounting is performed based on it. Correcting the position is required. for that reason,
It is considered that after the chip component is sucked by the suction nozzle of the head unit, the position of the chip component is detected by the article recognition device.

[0004]

As described above, the position of an article is detected by using the article recognition device, and in particular, the position of the chip component is detected in the component mounting device and the mounting position is corrected based on the detection. Then, it is necessary to quickly achieve a state in which an image that is as good as possible is obtained within the range of the depth of focus of the image capturing unit when the image is captured by the image capturing unit. For this reason, normally, in a preparatory step before component mounting work, etc., the operator can change the height position of the suction nozzle (the distance between the image pickup device and the object to be imaged) with respect to the fixed focus image pickup device, The position where an image is obtained is visually inspected, and this position is input as a set value.

However, such visual adjustment by the operator is troublesome and reduces the work efficiency, and it is difficult to accurately set and adjust the distance between the image pickup means and the object to be imaged. However, if the accuracy is low, the position detection by the image processing and the accuracy of the mounting position correction based on the position detection may be deteriorated.

In view of the above-mentioned circumstances, the present invention can automatically and accurately perform the work of presetting the interval between the two so that the image of the chip part or the like by the image pickup means becomes good. An object of the present invention is to provide an article recognition device that can improve accuracy.

[0007]

In order to achieve the above-mentioned object, the present invention provides an article recognition including an image pickup means and an image processing means for detecting the position of an object to be picked up from an image picked up by the image pickup means. The apparatus includes an interval setting means for setting an interval between the imaging means and the object to be imaged, and the interval setting means changes an interval between the imaging means and the object to be imaged in a state of being opposed to each other. And means for detecting the density distribution of the image, and means for detecting the interval at which a clear image is obtained based on the relationship between the interval and the density distribution and setting this as a set value. .

Particularly preferably, the article recognition device is provided in a component mounting apparatus having a head unit for sucking a chip component by a suction nozzle and mounting the chip component at a predetermined position, wherein the chip is suctioned by the suction nozzle. The component is imaged by the image pickup means, the position is detected by the image processing means, and the mounting position of the chip component is corrected based on this detection, and the interval setting means is the chip component of the suction nozzle. The distance between the suction position and the image pickup means is set.

[0009]

According to the above construction, when the distance between the image pickup means and the object to be picked up is set, the distance setting means automatically searches for a state in which a clear image can be obtained and picks up an image in this state. The interval between the means and the object to be imaged is set as a set value, and the interval is quickly adjusted to the set value at the time of imaging in the subsequent component mounting work or the like.

[0010]

Embodiments of the present invention will be described with reference to the drawings.
1 and 2 show the overall structure of a component mounting apparatus including an article recognition apparatus according to an embodiment of the present invention. In these drawings, a conveyer 2 for conveying a printed circuit board extending in the X-axis direction (conveying direction) is arranged on a base 1, and the printed circuit board 3 is conveyed on the conveyor 2, and a work station 6A, which will be described later, is provided. It is designed to be stopped at a fixed position of 6B.

On both sides of the portion where the conveyor 2 is arranged,
The component supply unit 4 is arranged. The component supply unit 4 includes a large number of rows of supply tapes 4a. Each supply tape 4a accommodates and holds small chip-shaped chip components such as ICs, transistors, and capacitors at equal intervals and is wound around a reel. ing. A ratchet type feed mechanism is incorporated at the feeding end of the supply tape 4a, and head units 5A and 5B described later are provided.
Thus, as the chip component is picked up from the feeding end, the supply tape 4a is intermittently fed out, and the above-mentioned pickup work can be repeated.

Further, head units 5A and 5B for mounting components are installed above the base 1, and the head units 5A and 5B and the printed circuit board 3 on the work stations 6A and 6B are relatively arranged on the X-axis. Direction and the Y-axis direction (the direction orthogonal to the X-axis on the horizontal plane). In the illustrated embodiment, the work stations 6A and 6B holding the printed circuit board 3 are movable in the Y-axis direction. The head units 5A and 5B are movable in the X-axis direction.

The structure will be described in detail. In the figure, the head units 5A and 5B and the work units are arranged in order to increase the processing efficiency by enabling the mounting work to be performed on the two printed circuit boards 3 simultaneously. Station 6A,
Two 6Bs are installed, and a work station 6
A and 6B are arranged at two positions shifted in the X direction.
Each of the work stations 6A, 6B has a substrate holding device for holding the printed circuit board 3, and can hold the printed circuit board 3 sent from the conveyor 2 to the work stations 6A, 6B via the transfer device. It is like this.

At the locations where the work stations 6A and 6B are arranged, two guide rails 8 extending in the Y-axis direction in parallel with each other are arranged on the base 7 at predetermined intervals in parallel with each other. As a Y-axis feed mechanism, a ball screw shaft 9 which is rotationally driven by a Y-axis servomotor 10 is arranged near one guide rail 8. Then, the work stations 6A, 6
Both side portions of B are movably supported by the guide rail 7, and nut portions 11 provided on the work stations 6A and 6B are screwed onto the ball screw shaft 9. With this structure, the work stations 6A and 6B move in the Y-axis direction as the ball screw shaft 9 rotates while holding the printed circuit board 3 during the component mounting work.

An X-axis frame for holding the head units 5A, 5B movably in the X-axis direction is provided above the base 1. Two X-axis frames 13A, 13A are shown in the figure.
13B are parallel to each other at predetermined intervals, and X
It extends in the axial direction. This X-axis frame 13A, 13B
Is formed with X-axis guides 14 on both upper and lower sides thereof, and as a feed mechanism in the X-axis direction, a ball screw shaft 15 positioned between the upper and lower X-axis guides and the ball screw shaft 15 are rotated. An X-axis servomotor 16 for driving is provided. The head units 5A and 5B are movably supported by the X-axis guide 14, and a nut portion (not shown) provided on the head units 5A and 5B is screwed onto the ball screw shaft 15 to form a ball screw. The rotation of the shaft 15 causes the head units 5A and 5B to move in the X-axis direction.

The head units 5A and 5B are provided with suction nozzles 20 for sucking chip components. In the illustrated example, each head unit 5A and 5B is provided with 16 suction nozzles 20. As shown in detail in FIGS. 3 and 4, each of the suction nozzles 20 is movable along the Z-axis guide 21 in the Z-axis direction (vertical direction) and at the same time around the R-axis (nozzle central axis). The Z-axis servo motor 22 and the R-axis servo motor 23 for the suction nozzle 20 are rotatable and can be rotated.
It is equipped with A and 5B. Then, the suction nozzle 20 is moved up and down via the Z-axis ball screw shaft 24 by driving the Z-axis servo motor 22, and the R-axis servo motor 2
R axis ball screw shaft 25, R axis rack 26 by driving 3
The suction nozzle 20 is rotated via the R-axis pinion 27. Furthermore, the head unit 5
A and 5B are printed on the printed circuit board 3 by detecting a mark (not shown) previously attached to the printed circuit board 3.
A board position detecting CCD camera 28 for detecting the position of is attached.

On the base 1, head units 5A, 5A
A CCD camera 31 as an image pickup means for detecting the component position is provided at a position corresponding to an appropriate position within the X-axis direction movement range of B, for example, a position between the work stations 6A and 6B and the component supply unit 4. And a lamp house 32 for illumination at the time of imaging. The CCD camera 31 has a fixed focus.

FIG. 5 schematically shows an image processing system. In this figure, a CCD camera 31 for detecting the position of a component is shown.
Is connected to an image processing unit (image processing means) 33. The substrate position detecting CCD camera 28 provided in each of the head units 5A and 5B is also connected to the image processing unit 33.

The lamp house 32 is connected to a flash unit 35 via a fiber cable 34, and the flash unit 35 is connected to the image processing unit 33. The image processing unit 33 is connected to the controller 36.

FIG. 6 schematically shows a head unit 5 (5A or 5B) equipped with a suction nozzle (only one is shown for simplification), a servomotor 22, etc., a CCD camera 31, a flash lamp 37 and an illumination power source 38. 2 and the functional configuration of the image processing unit 33 and the controller 36. Reference numeral 39 is a chip component sucked by the suction nozzle.

In this figure, the image processing unit 33 connected to the CCD camera 31 includes a component position detecting means 41 and an image density distribution detecting means 42. The component position detecting means 41 is configured such that the CCD camera 3 after the component is picked up by the suction nozzle 20 during the mounting work in which a series of work for sucking and mounting the chip component 39 is automatically performed.
The center position and the rotation angle of the chip part 39 are detected from the image of the chip part 39 captured in 1. Further, the density distribution detecting means 42 detects the density distribution of the image at the time of the interval setting process which will be described later in the preparation stage or the like.

The controller 36 connected to the image processing unit 33 comprises a microcomputer or the like,
Various drives such as an instruction / calculation unit 43, a storage unit 44 such as a ROM and a RAM, an interface 45, a head unit drive unit 46, a suction nozzle rotation drive unit 47, a suction nozzle vertical drive unit 48, and a work station drive unit 49. Includes departments. Then, various sensors 50, a suction vacuum supply / discharge switching valve 51, various servo motors 1
0, 16, 22, 23, etc. are electrically connected to the interface 45 and the drive units 46 to 49. Further, the keyboard 52 and the CRT 53 are connected to the controller 3
Connected to 6.

In the command / calculation means 43, the suction nozzle 20 is positioned above the CCD camera 31 in the interval setting process for setting the distance between the CCD camera 31 and the component suction position of the suction nozzle 20 in the preparation stage or the like. The interval changing means 54 for changing the interval by moving it up and down in the state of being positioned at, and the output of the concentration distribution detecting means 42 during the operation of this means 54 to check the change of the concentration distribution, and based on that, It has a set value calculating means 55 for obtaining an appropriate value of the interval as a set value and storing the set value in the storage means 44. These means 54 and 55 and the density distribution detection means 42 automatically detect and set the nozzle height position (the distance between the CCD camera 31 and the component suction position of the suction nozzle 20) at which a clear image is obtained. Interval setting means is configured.

The processing that fulfills the function of the interval setting means is
This will be described with reference to the flowchart of FIG.

The process of this flowchart is performed as a preparatory work before the automatic component mounting operation is performed when the CCD camera 31 and its parts are replaced. In this process, the object to be picked up by the suction nozzle 20 and picked up by the CCD camera 31 may of course be a chip part, but a jig having a black line on a white background is used as a substitute for the chip part. Good.

As the processing of this flowchart, first, in step S1, the chip component or jig is sucked by the suction nozzle 20, and the head unit 5 is moved in the X-axis direction to a position above the CCD camera 31.
Further, in step S2, the minimum height Hmin is given as the initial setting of the height H of the suction nozzle 21.

Then, the Z-axis servomotor 22 is driven to move the suction nozzle 20 to the nozzle height H (step S3). In this state, the lead portion of the chip component or the wire of the jig is moved. The density distribution of the part is examined (step S4). That is, for the image W of the chip component or the like displayed on the processing screen as shown in FIG.
Scanning is performed in the direction (arrow direction) that crosses (or the line portion), and by this scanning, the density distribution as shown in FIG. 9 in which the lightness and darkness change between each lead portion and between the leads is obtained.

Subsequently, the deviation L [H] between the highest and the lowest density is obtained from the above density distribution (step S5).
Then, the nozzle height H is increased by a constant value S (step S6), and the nozzle height H is determined (step S6).
Based on 7), the processes from step S3 are repeated until the nozzle height H reaches the maximum value Hmax. As a result, the concentration distribution is examined for each nozzle height that has changed by the constant value S, and the deviation L [H] is obtained.

When the nozzle height H reaches the maximum value Hmax, the maximum value is examined among the density deviations at each nozzle height obtained by repeating the processing of steps S3 to S6, and the maximum value is determined. The taken nozzle height is set as a set value Ho for adjusting the nozzle height at the time of picking up a chip component in the subsequent component mounting operation (step S8), and this set value Ho is stored.

According to the apparatus of the present embodiment as described above, the nozzle height H is automatically set by the processing of the above-mentioned flowchart performed at the preparation stage and the like. Then, in this case, the density distribution is examined while changing the nozzle height H, and the nozzle height at which the density deviation L [H] is maximized is obtained, that is, the contrast is the best,
The nozzle height at which a clear image is obtained is obtained, and this is set as the set value Ho.

In the subsequent component mounting work, a series of work of suctioning the components by the head units 5A and 5B, detecting the component position by the article recognition device and calculating the mounting position correction amount based on it, and mounting the component on the printed circuit board 3 are performed. It is done automatically. That is, first, the suction nozzle 20 of the head unit 5A, 5B sucks the chip component from the component supply unit 4, then the head unit 5A, 5B moves to a position corresponding to the CCD camera 31, and the suction nozzle 2
After the height of 0 is adjusted to the set value Ho, the chip component is imaged and the position of the chip component is detected by the image processing.

In this image processing, an image displayed on the processing screen is scanned to detect, for example, end edge points of the lead portion on the four sides of the chip component, and to detect the position of each edge point. Based on this, the center position of the chip part is calculated, and the direction connecting the edge points is checked, so that the rotation angle of the chip part is checked.

When such image processing is performed,
The set value H of the nozzle height is set in advance so that a clear image can be obtained.
Since o is given, the position can be accurately detected even in the case of a small chip component or a chip component having a narrow lead portion pitch.

Then, after the correction amount of the mounting position is obtained based on this position detection, the work of holding the printed circuit board 3 so that the chip component is mounted at the corrected target position on the printed circuit board 3. Y at stations 6A and 6B
Axial movement and movement of the head units 5A and 5B in the X-axis direction are performed, and the suction nozzle 2 at the mounting position
Decrease of 0, suction negative pressure cut, etc. are sequentially performed.

The suction nozzle 20 and the CCD camera 31
As a structure for setting and adjusting the interval between the CCD camera 31 and the base 1, the CCD camera 31 may be moved up and down with respect to the base 1, and the height of the CCD camera 31 may be adjusted by moving the CCD camera 31 up and down with a drive mechanism. .

Further, in the above embodiment, the interval setting means for presetting the distance between the image pickup means and the object to be imaged based on the density distribution of the image is applied to the image processing for detecting the position of the chip component. However, it can also be applied to a portion in which the position of the printed circuit board 3 is detected based on the image pickup of the mark on the printed circuit board 3 by the CCD camera 28 attached to the head units 5A and 5B.

Further, the overall structure of the component mounting apparatus is not limited to the above embodiment, and for example, the printed circuit board 3 may be positioned and stopped at the time of mounting, while the head unit may be moved in the X-axis direction and the Y-axis direction. It may be possible to have a structure.

[0038]

According to the present invention, in the article recognition device for detecting the position of the object to be imaged from the image of the object to be imaged by the image pickup means, the interval setting means for setting the interval between the image pickup means and the object to be imaged. This means detects the density distribution of the image while changing the interval between the image pickup means and the object to be imaged while facing each other, and detects the interval at which a clear image is obtained based on this. Since this is set as the set value (claim 1), the interval can be adjusted and set automatically and the work efficiency can be improved. Moreover, since the state in which the clearest image is obtained can be searched and set, the accuracy of position detection by image processing can be improved.

In particular, when the position of the chip component sucked by the suction nozzle of the head unit in the component mounting apparatus is detected by image processing and the mounting position of the chip component is corrected based on this detection, If the distance between the chip component suction position of the suction nozzle and the image pickup means is set by the distance setting means (claim 2), it is possible to obtain a small chip component or a chip component with a narrow lead portion pitch. Also, it is possible to accurately detect the position by image processing and correct the component mounting position based on it.

[Brief description of drawings]

FIG. 1 is a plan view of a component mounting device including an article recognition device according to an embodiment of the present invention.

FIG. 2 is a front view of a head unit arrangement portion of the component mounting apparatus.

FIG. 3 is an enlarged front view of a head unit.

FIG. 4 is a view of the head unit as seen from a line IV-IV in FIG.

FIG. 5 is a perspective view schematically showing a head unit, an image processing device, and the like.

FIG. 6 is a block diagram showing a mechanical configuration of an image processing and control system.

FIG. 7 is a flowchart showing a process that functions as an interval setting unit.

FIG. 8 is an explanatory diagram showing scanning for density distribution detection.

FIG. 9 is an explanatory diagram showing a density distribution.

[Explanation of symbols]

 5A, 5B Head unit 20 Adsorption nozzle 31 CCD camera (imaging means) 33 Image processing unit 36 Controller 42 Concentration distribution detection means 43 Command / calculation means

Claims (2)

[Claims] 1. An article recognition device comprising image pickup means and image processing means for detecting the position of an object to be picked up from an image picked up by the image pickup means, wherein an interval between the image pickup means and the object to be picked up is set. And a means for changing the distance between the image pickup means and the object to be imaged, a means for detecting a density distribution of an image, and the distance setting means. An article recognition device, comprising means for detecting an interval at which a clear image is obtained based on the relationship with the density distribution and setting the interval as a set value. 2. An article recognition device provided in a component mounting apparatus having a head unit for sucking a chip component by a suction nozzle and mounting the chip component at a predetermined position, wherein the chip component sucked by the suction nozzle is The position is detected by the image processing means by being imaged by the imaging means,
2. The chip component mounting position is corrected based on this detection, and the interval setting means sets an interval between the chip component suction position of the suction nozzle and the image pickup means. Parts recognition device.