JP3564263B2 - Component recognition device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a component recognition device that recognizes a position shift of a component held and transported by a holder with respect to the holder.
[0002]
[Prior art]
In this type of component recognition device, a holder holding a conventional component is stopped and stopped at a position where the component is recognized by a component recognition camera, and thereafter, a positional shift of the component with respect to the holder is recognized based on the captured component image. And so on, when it is mounted at a desired position, such as when it is mounted. 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 component 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. The position of the nozzle, which is a holder, is recognized by recognizing the position of the mark.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional technology, the mark must be recognized together with the component, and the recognition process takes a long time. In addition, when a large component is to be recognized, the mark must be provided outside the component. However, there is a problem in that the range of the recognized image including the mark is increased or the range of the recognized image including the mark is enlarged.
[0004]
Therefore, an object of the present invention is to make it possible to reliably recognize the position of a component held by a holder without stopping the holder.
[0005]
[Means for Solving the Problems]
Therefore, the present invention provides a component recognition device that recognizes a positional shift of a component held and conveyed by a holder with respect to the holder, an imaging unit that captures a component image, and an image captured by the imaging unit is captured and stored. Image 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 time when the component image is captured by the image capture means; Position calculating means for calculating the position of the holder when the component image is captured by the image capturing means based on the time difference detected by the means; and the component image stored in the image storage means and the holding calculated by the position calculating means. Recognition processing means for performing position recognition of the component based on the position of the component.
[0006]
By doing so, it is possible to know the position of the holder when the component image is actually captured, and to correct the error that the position of the holder is different from when the capture command is issued, and to recognize the position of the component. Can be.
[0007]
Further, according to the present invention, in the component recognition device according to claim 1, the detection unit measures an image by measuring a time difference between a time point at which the image storage unit has finished capturing an image and a time point of a capture command of the capture command unit. This is to detect the time lag taken by the means.
[0008]
Further, according to the present invention, in the component recognition apparatus according to claim 2, the imaging unit synchronously generates an imaging timing and a vertical synchronization signal when scanning the captured component image, and Is a device for detecting a time difference between a time point of imaging and a time point of a capture command based on a vertical synchronizing signal sent to the image storage means.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0010]
In FIG. 2, a pair of conveyors 3 are provided on a base 2 of the electronic component automatic mounting apparatus 1, and the conveyor 3 transports a printed circuit board 4 from an upstream apparatus. The substrate 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 X and Y directions sucks is mounted on the substrate 4.
[0011]
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. Further, 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 that moves in XY directions. The nozzle 6 is vacuum-sucked and mounted on the substrate 4 as described above.
[0012]
A component imaging camera 14 which is a CCD camera as an imaging unit is installed on the base 2, and the head 5 that has taken out the component 7 from each component supply unit is transported onto the camera 14.
[0013]
Next, a control block of the electronic component automatic mounting apparatus 1 will be described with reference to FIG.
[0014]
Reference numeral 25 denotes a CPU, which comprehensively controls operations related to component mounting of the electronic component automatic mounting apparatus in accordance with a program stored in a ROM 27 based on data stored in a RAM 26 via a bus line 24. A motor control interface 28, a frame memory 29 as an image storage device, and a recognition processing unit 30 are further connected to the bus line 24. The mounting head moving motor 32 is connected to the motor control interface 28 and drives the movement of the mounting head 5. Note that two motors are provided for two XY axes so that the mounting head 5 can move in the horizontal XY directions, but only one motor is shown in FIG. The frame memory 29 stores the component images captured by the component imaging camera 14, and stores the images captured by the camera 14 in response to an image capture command from the CPU 25. The recognition processing unit 30 performs a recognition process 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 image signal of the camera 14 is being captured or has been captured. The CPU 25 can check the information. A component recognition device is configured by the component imaging camera 14, the CPU 25, the frame memory 29, the recognition processing unit 30, and the like.
[0015]
Hereinafter, the operation will be described.
[0016]
First, when the production operation of the electronic component automatic mounting apparatus 1 is performed, the suction nozzle 6 suctions and transports the electronic component 7 indicated by the mounting data (not shown) from the component supply unit 10.
[0017]
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, The position of the suction nozzle 6 as a holder can be grasped.
[0018]
Next, the mounting head 5 holding the component 7 passes over the component imaging camera 14.
[0019]
During this passage, 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 as a holder is recognized. The recognition processing operation will be described in detail below.
[0020]
The CPU 25 issues a capture command to the frame memory 29 to capture the image of the component 7 captured by the component capturing camera 14 when the mounting head 5 reaches a predetermined position on the camera 14 where the camera 14 can capture the component 7. . A capture command is issued at the point A of the stage movement in FIG.
[0021]
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 synchronizing 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 a point B next to the point A to which the capture command is issued is loaded into the frame memory 29.
[0022]
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 almost stopped in view of the moving speed of the mounting head 5). The end point of the shutter release is set to be almost the same as the end point (rising position) of the vertical synchronizing signal, and the starting point of the next vertical synchronizing signal from this point (point C). The light-receiving elements that are exposed during this period are scanned, and at the same time, a video output signal is taken into the frame memory 29 as a video signal of one field (1/60 second).
[0023]
Here, the capture command of the CPU 25 and the vertical synchronization signal of the camera 14 are output separately and are not synchronized, so that the capture command is issued (point A in FIG. 1) and the vertical synchronization signal (point B in FIG. 1). Is not constant, and the position of the mounting head 5 at the point D cannot be calculated with the time difference from the point D at which the shutter is opened being constant.
[0024]
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 at the point C which is the start point of the next vertical synchronization signal at which the capture ends. It becomes "0".
[0025]
At this time, the CPU 25 captures the time at the point C when the capture state register 33 has changed to “0”, calculates the time difference from the time at the point A at which the capture command has already been stored in the RAM 26, and calculates the time difference between the DC points. Is constant, the time difference between the AD points is calculated. That is, the time difference when the component image rich in the fetch instruction is captured by the image capturing means is detected. This detecting means is constituted by the CPU 25 and the fetch state register 33 in the frame memory 29.
[0026]
Further, 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.
[0027]
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.
[0028]
Next, the calculated displacement of the electronic component recognized as the position of the mounting head 5, that is, the suction nozzle 6, is calculated.
[0029]
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. However, the difference between the position of the suction nozzle 6 at the time of the take-in command and the position of the component at the time of imaging affects the horizontal position shift.
[0030]
Next, the mounting head 5 that has passed over the component mounting camera 14 stops the mounting head 5 at a position corrected for the 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, The suction nozzle 6 is rotated by a nozzle rotation mechanism (not shown).
[0031]
Next, the electronic component 7 is mounted on the printed board 4 by lowering the suction nozzle 6.
[0032]
Hereinafter, similarly, the operation of sucking the component 7 to be next sucked from the component supply unit, similarly capturing and recognizing the mounting head 5 while the mounting head 5 is passing over the camera 14, and mounting the component on the printed board is repeated.
[0033]
【The invention's effect】
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 command is issued, and recognizes the position of the component with respect to the holder. And accurate position recognition can be performed regardless of the size of the component.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the timing of signals such as a component imaging camera and a capture command relating to 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]
5 Chip-shaped electronic components 6 Suction nozzle (holding tool)
7 Chip-shaped electronic component 14 Component imaging camera (imaging means)
25 CPU (acquisition command means) (position calculation means) (recognition processing means)
29 frame memory (image storage means)
30 Recognition processing unit (recognition processing means)

Claims (3)

In a component recognition device that recognizes a positional shift of a component held and transported by a holder with respect to the holder,
Image capturing means for capturing a component image, image storing means for capturing and storing the image captured by the image capturing means, capturing command means for instructing to capture the component image captured by the image capturing means into the image storing means, and capturing command A detecting unit that detects a time difference when the component image is captured by the imaging unit, and a position calculating unit that calculates a position of the holder when the component image is captured by the imaging unit based on the time difference detected by the detecting unit. A component recognizing apparatus, further comprising: recognition processing means for recognizing the position of the component based on the component image stored in the image storage means and the position of the holder calculated by the position calculation means. 5. The image processing device according to claim 2, wherein the detecting unit measures a time difference between a time point when the image capturing in the image storing unit is completed and a time point of the capturing command of the capturing command unit to detect a time difference captured by the image capturing unit. 2. The component recognition device according to claim 1. The imaging unit synchronously generates an imaging timing and a vertical synchronization signal when scanning the captured component image, and the detection unit performs imaging based on the vertical synchronization signal sent to the image storage unit. 3. The component recognition apparatus according to claim 2, wherein a time difference between the time point and the time point of the capture command is detected.

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