JPH1117396A - Part-recognizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively recognize the position of parts being retained by a retainer, without stopping the retainer. SOLUTION: When a placement head 5 reaches a specified position on a part image-pickup camera 14, a CPU 25 issues a reading command, and an image output signal picked up by opening the shutter of a next vertical synchronous signal is taken into a frame memory 29. The reading end time is read by the CPU 25. The time, which is the difference to the time when the reading command is issued, is calculated, and the misalignment of an electronic component 7 is recognized based on the position of a suction nozzle 6 on the image- pickup being calculated according to the difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component recognizing device for recognizing a positional shift of a component held and conveyed by a holder with respect to the holder.

[0002]

2. Description of the Related Art In a component recognition apparatus of this type, a holder holding a conventional component is stopped and stopped at a position where the component is recognized by a component recognition camera, and then the positional deviation of the component with respect to the holder is determined based on the captured component image. It has been recognized and corrected when mounted at a desired position on a printed circuit board or the like. In this case, there is a problem in that once the holder stops at the position where the image is captured by the camera, it takes a long time to mount components. For this reason, it is conceivable to take a part image while the transfer head is moving, as in the technique described in Japanese Patent Application Laid-Open No. Hei 7-263897. When the image is taken during the movement, the holder holding the component is hidden by the component, so the positional relationship with the holder cannot be recognized. However, in order to solve this, the recognition mark is placed at a position distant from the suction nozzle of the transfer head. And the position of the nozzle as a holder and the position of the component are recognized by recognizing the position of the mark.

[0003]

However, in the above-mentioned prior art, the mark must be recognized together with the part, and the recognition process takes a long time. Since the parts must be attached, there is a problem that the size of the part is limited or the range of the recognition processing image including the mark becomes large.

SUMMARY OF THE INVENTION It is an object of the present invention to reliably recognize the position of a component held by a holder without stopping the holder.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention relates to a component recognizing apparatus for recognizing a displacement of a component held and conveyed by a holder with respect to the holder, an image pickup means for picking up a component image, Image storage means for capturing and storing an image captured by the means, capture instruction means for instructing the image storage means to capture the component image captured by the image capture means, and a time difference when the capture instruction and the component image are captured by the image capture means. Detecting means, a position calculating means for calculating the position of the holder when the component image is captured by the imaging means based on the time difference detected by the detecting means, and a component image stored in the image storage means. And a recognition processing means for recognizing the position of the component based on the position of the holder calculated by the position calculation means.

[0006] With this configuration, the position of the holder when the component image is actually taken can be known, and the error that the position of the holder is different from the position when the fetch command is issued is corrected. Can be recognized.

Further, according to the present invention, in the component recognition apparatus according to the first aspect, the detecting means measures a time difference between a time point when the image storage is completed in the image storage means and a time point when the capture command is issued by the capture command means. In this way, the time difference captured by the imaging means is detected.

According to a second aspect of the present invention, in the component recognition device according to the second aspect, the imaging means synchronously generates an imaging timing and a vertical synchronization signal when scanning the captured component image, The detecting means detects a time difference between the time of imaging and the time of a capture command based on the vertical synchronization signal sent to the image storage means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 2, a pair of conveyors 3 are provided on a base 2 of the automatic electronic component mounting apparatus 1, and the conveyor 3 transfers a printed circuit board 4 from an upstream apparatus. The board 4 is positioned at a predetermined position, and a chip-shaped electronic component 7 (see FIG. 3) to which a suction nozzle 6 provided on a mounting head 5 that moves in the XY directions sucks is mounted on the board 4.

The mounting head 5 is provided on the arm 7 so as to be movable in the X direction, and the arm 8 is provided along a guide 9 so as to be movable in the Y direction. A tape component supply unit 10, a tray component supply unit 11, and a stick component supply unit 12 are provided on the base 2, and various components 7 to be supplied are provided on the head 5 which moves in XY directions. The nozzle 6 is vacuum-sucked and mounted on the substrate 4 as described above.

A component imaging camera 14, which is a CCD camera as an imaging means, is installed on the base 2, and the head 5 which has taken out the component 7 from each component supply unit is conveyed onto the camera 14.

Next, a control block of the automatic electronic component mounting apparatus 1 will be described with reference to FIG.

Reference numeral 25 denotes a CPU, which is based on data stored in a RAM 26 through a bus line 24,
In accordance with the program stored in 7, the operation relating to the component mounting of the electronic component automatic mounting apparatus is generally controlled. Bus line 2
4 also has a motor control interface 2
8. A frame memory 29 as an image storage device and a recognition processing unit 30 are connected. The motor control interface 28 includes a mounting head moving motor 32.
Are connected to drive the movement of the mounting head 5. still,
Although two motors are provided for two XY axes so that the mounting head 5 can move in the horizontal XY directions, only one motor is shown in FIG. The frame memory 29 stores a component image captured by the component imaging camera 14.
The image captured by the camera 14 is stored in response to an image capture command from the CPU 25. Recognition processing unit 30
Performs recognition processing on the image. The frame memory 29 is provided with a capture status register 33 that indicates the status of capture of an image from the component imaging camera 14, and indicates whether the capture of the image signal of the camera 14 is being performed or the capture has been completed. The CPU 25 can check the information. Component imaging camera 14,
CPU 25, frame memory 29, recognition processing unit 3
0 and the like constitute a component recognition device.

The operation will be described below.

First, when the production operation of the electronic component automatic mounting apparatus 1 is performed, the suction nozzle 6 sucks and transports the electronic component 7 indicated by the mounting data (not shown) from the component supply unit 10.

This conveyance is performed by moving the mounting head 5 by driving the motor 32, and the motor 32 rotates under the control of the motor control interface 28. The CPU 25 obtains information from the motor control interface 28, and 5 That is,
The position of the suction nozzle 6 as a holder can be grasped.

Next, the mounting head 5 holding the component 7 passes over the component imaging camera 14.

At this time, the electronic component 7 is imaged by the camera 14 and the displacement of the electronic component 7 with respect to the suction nozzle 6 serving as a holder is recognized. The recognition processing operation will be described in detail below.

When the mounting head 5 reaches a predetermined position on the camera 14 where the camera 14 can image the component 7, the CPU 25 captures the image of the component 7 captured by the component imaging camera 14 into the frame memory 29. Issue a command. A capture command is issued at the point A of the stage movement in FIG.

In the component imaging camera 14, as shown in FIG. 1, when the shutter (electronic shutter) is always opened, an image is captured by exposing the light receiving element of the CCD camera.
This exposure state is scanned for each vertical synchronization signal, and the video output signal is taken into the frame memory 29 from the camera 14. The shutter of the camera 14 is opened in synchronization with the vertical synchronization signal as shown in FIG. In FIG. 1, a video output signal of one field (field 1 in FIG. 1) starting from a vertical synchronizing signal starting from point B next to point A to which the capture command has been issued is taken into frame memory 29.

More specifically, the opening of the shutter is started at point D in synchronization with the vertical synchronizing signal (the opening time of the shutter is 1/10000 second, and this interval is slightly different from the moving speed of the mounting head 5). It is considered that the shutter is almost stopped.), The end point of the shutter release is set to be substantially the same as the end point (rising position) of the vertical synchronization signal,
Each of the exposed light receiving elements is scanned from this time to the start of the next vertical synchronizing signal (point C), and at the same time, a video output signal is stored in the frame memory 29 for one field (1/60).
Second) video signal.

Here, the capture command of the CPU 25 and the vertical synchronizing signal of the camera 14 are output separately and are not synchronized, so that the time when the capturing command is issued (point A in FIG. 1) and the vertical synchronizing signal (B in FIG. 1). The time difference from the point D) is not constant, and the time difference from the point D at which the shutter is opened is fixed.
The position of the mounting head 5 at a point cannot be calculated.

On the other hand, while the captured image at the point D is being captured in the frame memory 29, the capture state register 33
Is set to “1”, and becomes “0” at the point C which is the start point of the next vertical synchronization signal at which the capture ends.

At this time, the CPU 25 captures the time at the point C when the capture state register 33 has changed to "0", and calculates the time difference from the time at the point A at which the capture command is already stored in the RAM 26, Since the time difference between the DC points is constant, the time difference between the AD points is calculated. In other words, the time difference when the component image rich in the fetch instruction is captured by the image capturing means is detected. This detection means is a CPU
25, capture status register 3 in frame memory 29
3.

The speed at which the mounting head moves between the AD points is considered to be substantially constant, and since this speed is also known, the position of the mounting head 5 at the point D is calculated. This position calculating means is the CPU 25.

On the other hand, when the video output signal of the component image is stored in the frame memory 29, the recognition processing unit 30 recognizes the positional deviation between the image of the electronic component 7 and the screen center, and transfers the result to the CPU 25. .

Next, the positional deviation of the electronic component recognized as the calculated position of the mounting head 5, that is, the suction nozzle 6, is calculated.

The calculation of the displacement includes not only the displacement in the horizontal direction, that is, the XY direction, but also the displacement of the rotation angle about the vertical axis. It should be noted, however, that the displacement between the position at the time of the command to take in the suction nozzle 6 and the position at the time of imaging the component affects the displacement in the horizontal direction.

Next, the mounting head 5 that has passed over the component mounting camera 14 moves the mounting head 5 to a position corrected for positional deviation calculated so that the component 7 can be mounted at a position indicated by data (not shown) on the printed circuit board 4. Then, the suction nozzle 6 is rotated by a nozzle rotation mechanism (not shown).

Next, the electronic component 7 is mounted on the printed circuit board 4 by lowering the suction nozzle 6.

In the same manner, the component 7 to be next sucked is sucked from the component supply unit, and the mounting head 5 is similarly moved to the camera 1.
The operation of taking an image and recognizing it while passing over it and mounting it on a printed board is repeated.

[0033]

As described above, the present invention corrects an error between the position of the holder at the time when the component image is captured and the position of the holder at the time when the image capturing instruction is issued, and corrects the error for the component holder. Position recognition can be performed, and accurate position recognition can be performed regardless of the size of the component.

[Brief description of the drawings]

FIG. 1 is a diagram showing the timing of signals such as a component imaging camera and a capture command regarding component recognition.

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

FIG. 3 is a control block diagram of the electronic component automatic mounting apparatus.

[Explanation of symbols]

Reference Signs List 5 chip-shaped electronic component 6 suction nozzle (holding tool) 7 chip-shaped electronic component 14 component imaging camera (imaging means) 25 CPU (capture instructing means) (position calculating means) (recognition processing means) 29 frame memory (image storing means) 30 Recognition processing unit (recognition processing means)

Claims (3)

[Claims] 1. A component recognizing device for recognizing a positional shift of a component held and conveyed by a holder with respect to the holder, an imaging unit for capturing a component image, and an image for capturing and storing an image captured by the imaging unit. Storage means, capture instruction means for instructing the image storage means to capture a component image captured by the image capture means, detection means for detecting a time difference between the capture instruction and the component image being captured by the image capture means, and the detection means Position calculating means for calculating the position of the holder when the component image is captured by the imaging means based on the detected time difference, and the component image stored in the image storage means and the holder calculated by the position calculating means And a recognition processing means for recognizing the position of the component based on the position of the component. 2. The method according to claim 1, wherein the detecting unit measures a time difference between a time point when the image storage unit has finished capturing the image and a time point when the capture command is issued by the capture command unit to detect the time difference captured by the image capturing unit. The component recognition device according to claim 1, wherein: 3. The image pickup means synchronously generates an image pickup timing and a vertical synchronizing signal when scanning a picked-up part image, and the detecting means outputs the vertical synchronizing signal sent to the image storage means. 3. The component recognition apparatus according to claim 2, wherein a time difference between a time point of the imaging and a time point of the capture command is detected based on the signal.