JPH07142896A - Method for detecting position of lead of printed board and automatic cutter for lead of printed board - Google Patents

Abstract

PURPOSE:To provide a method for detecting a position of a lead for automatically cutting an end part of the lead protruding from a printed board after electronic components are mounted on the board and realize an automatic cutter for the lead. CONSTITUTION:A printed board A is turned on a turntable 1, a lead is recorded by a CCD camera 2 fixed horizontally with the board, and a position of the lead end protruding on the board by a predetermined length or longer is specified from a plurality of recorded images by turning. The specified data is sent to a cutting robot for cutting off the end of the lead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead wire position detecting method for automatically cutting a terminal portion of a lead wire protruding from a board after mounting an electronic component on the printed board and an automatic cutting of the lead wire. It relates to the device.

[0002]

2. Description of the Related Art When mounting electronic components on a printed circuit board, it is necessary to solder lead wires for the electronic components and lead wires for circuit construction. After the soldering of the lead wire is completed, the extra lead wire end protrudes from the substrate and must be cut off. Therefore, in the cutting work of the lead wire ends, mechanization of cutting the protruding lead wire ends at once is considered, but when the above-mentioned mechanization means is adopted,
A shearing force acts from one direction on the lead wire, and a force also acts on the soldered portion, resulting in poor connection of the soldered portion. For this reason, in reality, each lead wire is manually cut.

Further, particularly in the case of automating the lead wire cutting process in mass production of circuit devices, a predetermined lead wire is set by a lead wire cutting robot in which a substrate on which electronic components are mounted is set at a predetermined position and a cutting position is inputted in advance. The terminal part is being cut off.

[0004]

As described above, most of the cutting process of the lead wire of the printed circuit board is carried out manually, and in the automation using the cutting robot, the type of parts is changed. Each time, it is necessary to input the cutting position by manual processing.

The inventors of the present invention first set the printed circuit board to the CCD.
We took a picture with a camera and proposed a method to identify the position of the lead wire from the photographed image and conducted an experiment (announced at the 1992 IEICE Shin-Etsu Branch Conference and 1993 IEICE Spring Conference). In this experiment, the substrate was rotated while the image was taken from the horizontal direction, and the lead wire position was calculated based on only the imaged position of the taken lead wire and the rotation angle.

However, in reality, the image is taken away from the center at a position closer to the camera and closer to the center at a position far away from the camera. There is an error. To reduce the error, a CCD camera may be installed far away, but this is a practical obstacle.
Therefore, the present invention is further improved to propose a lead wire position automatic detection means suitable for practical use, and an automatic cutting device adopting the same means.

[0007]

According to a lead wire position detecting method for a printed circuit board of the present invention, the printed circuit board is rotated on a turntable, and lead wires protruding on the board at different rotation positions are attached to the board. CCD fixed in position and in the horizontal direction so that the focus of the image center matches the center of the substrate
Take a picture with a camera and set a processing unit that virtualizes the plane coordinates of the board in advance, and input to the processing unit continuous coordinates on a virtual coordinate plane that corresponds to the viewing angle of the lead wire that is longer than a predetermined length in the image pickup. However, the area other than the input coordinates is discriminated as the lead wire nonexistent area, and the coordinate position other than the lead wire nonexistent area remaining after the input processing at an appropriate substrate rotation angle protrudes beyond the predetermined length on the board. It is characterized in that it is specified as the position of the terminal portion.

The automatic lead wire cutting device for a printed circuit board according to the present invention takes a turntable for rotating the printed circuit board and a lead wire projecting on the board at different rotational positions from the horizontal direction of the board position. At the same time, a CCD camera in which the focal point of the image center coincides with the center of the substrate, and a processing unit which performs arithmetic processing based on the above-described detection method to identify the position of the lead wire terminal portion protruding beyond a predetermined length on the substrate. A transfer mechanism that transfers the substrate from the turntable to the cutting processing table, and a cutting processing mechanism that is provided on the cutting processing table and cuts the lead wire protruding portion at a predetermined position according to an instruction from the processing section. It is characterized by.

[0009]

[Operation] The substrate on the turntable is CCD from the horizontal direction.
When taken with a camera, an image of the protruding leads on the substrate is obtained. The lead wire position on the substrate is specified by arithmetically processing a plurality of image data obtained each time the turntable is rotated by a predetermined angle.

Specifically, the processing unit for calculating the position is
A memory section is assumed assuming an array of the plane coordinates X × Y of the substrate, and the memory of the entire array is temporarily set to “1”. Then, as shown in FIG. 2C, the image of the substrate of FIG. 2A is an image taken at the positions where the lead wires a1 to a5 are the focal positions n1 to n5. Therefore, first, it is determined that a5 that is equal to or less than the threshold value is not required to be cut, and is excluded.
One-dimensional coordinates on n4 image (corresponding to camera viewing angle)
Is replaced with continuous coordinates on the plane coordinates of the viewing angle where the lead line exists (linear equation of the plane coordinates: straight line), it is determined that there is no lead line other than the continuous coordinates, and the corresponding portion is set to “0”. Reset to. When the turntable is further rotated and the same processing is repeated at different positions, the position of "1" remains unchanged. Therefore, the barycentric coordinate position (detection position) of the “1” lump area can be estimated as the lead line position.

In the automatic lead wire cutting device, when the lead wire position detection is completed, the substrate is conveyed from the turntable to the cutting processing table, and the detected position is input to the cutting mechanism section (cutting robot). The lead wire protruding portion is cut off.

[0012]

EXAMPLES Next, examples of the present invention will be described. The apparatus of the embodiment includes a turntable 1, a CCD camera 2, a data processing section 3, a transport mechanism section 4, and a cutting processing mechanism section 5.
Composed of and.

The turntable 1 is for placing and rotating the printed circuit board A on which the electronic parts have been mounted at a predetermined position, and the CCD camera 2 has the turntable 1 at a position separated by a predetermined horizontal distance. The printed circuit board A is installed and the printed circuit board A on the turntable 1 is photographed.

The processing unit 3 is a computer for specifying the position of the lead wire a on the substrate A from the image captured by the CCD camera 2 and controlling the operations of the transport mechanism unit 4 and the cutting mechanism unit 5 which will be described later.

The transfer mechanism section 5 holds the substrate A on the turntable 1 and holds the substrate A, and the cutting processing table 5 of the next cutting processing section 5 is held.
The cutting processing mechanism unit 5 is provided on the cutting table 51 and the cutting processing table 51, and cuts the protruding portion of the lead wire a at a predetermined position according to an instruction from the processing unit 3. It consists of 52.

The operation of the apparatus of the above embodiment will be described below. The printed board A is placed on the turntable 1, the turntable 1 is rotated, and the board A is photographed by the CCD camera 2 from the horizontal direction at different rotation angle positions. For example, the shooting image is as illustrated in FIG. The lead wire a protruding from the substrate A by a predetermined value (threshold value) or more is grasped as coordinates of n1, n2, n3, and n4 on the captured screen. That is, the short lead wire a5 that does not need to be cut is not detected and excluded from the objects to be cut.

Next, the imaged coordinates of the lead wire a when the table 1 is rotated by a predetermined angle are sequentially input to the processing section 3, and the processing section 3 calculates the position of the lead wire. The processing unit 3 reserves a memory unit assuming an array of plane coordinates X × Y of the virtual substrate A whose coordinate unit is subdivided at least from the thickness of the lead wire. The memory for all arrays is "1"
Then, from the one-dimensional coordinates (corresponding to the camera viewing angle) on the image of the leads above the predetermined threshold value among the leads in the image of the board, on the plane coordinates of the viewing angle where the lead exists. Continuous coordinates (linear equation of plane coordinates: straight line)
Is determined, it is determined that there is no lead wire other than the continuous coordinates, and the relevant portion is reset to “0”. When the turntable is further rotated and the same processing is repeated at different positions, the position of "1" remains unchanged. Therefore, the barycentric coordinate position (detection position) of the “1” lump area can be estimated as the lead line position.

As a simple example, when there is a substrate A that needs to be cut a1 and a2 as shown in FIG. 3A, the image pickup coordinates of the lead wire at a predetermined position are n1 and n2 (for convenience, a camera is used). The focal point is set to the back of the substrate), and continuous coordinates on the plane coordinates (linear equation of the plane coordinates: straight line) in the viewing angle direction from the camera position where the lead lines a1 and a2 exist are obtained, and other than the above continuous coordinates. Determines that there is no lead wire and resets the relevant portion to "0" (FIG. 3B).

Next, the lead wires a1 and a2 in an image taken when the turntable 1 is rotated by a predetermined angle (for example, 45 °).
Similar processing is performed based on the image-capturing coordinates m1 and m2 of FIG. Further, the turntable 1 is rotated by 90 °, and the lead wires a1 and a2 are similarly photographed.
Similar processing is performed based on the two image capturing coordinates l1 and l2 (FIG. 3D). Then, the coordinate position of the lead line position can be specified on the assumed substrate coordinates.

In the above example, there are two lead wires a, so 0
Although it was possible to specify the angle of 45 °, 45 °, and 90 °, when there are a plurality of lead wires, a large number of processes are required at a fine angle, and the detection process of several rotations is performed in consideration of image noise. When the detection process at different rotation angle positions is repeated in this way, "1"
The position of does not change. Therefore, the barycentric coordinate position (detection position) of the "1" lump area can be estimated as the positions of the lead wires a1 and a2.

When the position detection of the lead wire a of the substrate A is completed, the transfer mechanism unit 3 transfers the substrate A from the turntable 1 to the cutting processing table 51, and the processing unit 4 transmits the detection position to the cutting robot 52. A predetermined cutting operation is performed by the cutting robot 52. On the other hand, the next substrate is sent to the turntable 1 next to the above cutting work, and the position of the lead wire is detected.

[0022]

As described above, according to the present invention, after the electronic parts are mounted on the printed circuit board, the printed circuit board is rotated on the turntable in order to automatically cut the end portions of the lead wires protruding from the printed circuit board. , Which captures the lead wires protruding on the substrate from different rotation angle positions with a CCD camera in a horizontal position, and specifies the position of the lead wire terminal protruding above a predetermined length on the substrate based on a plurality of images. Thus, the automatic detection of the position on the substrate of the lead wire that requires cutting and the practical application of the automatic cutting of the lead wire have been achieved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus according to an embodiment of the present invention.

2A and 2B are explanatory views of a photographing means of the lead wire, in which (A) shows a photographing state, (B) shows the same photographing state, and (C) shows a photographing state from a plane.

FIG. 3 is an explanatory diagram of a procedure for identifying the lead wire.

[Explanation of symbols]

 1 Turntable 2 CCD Camera 3 Processing Section 4 Conveying Mechanism Section 5 Cutting Processing Section 51 Cutting Table 52 Cutting Lohot

Claims (2)

[Claims] 1. A printed circuit board is rotated on a turntable, and lead wires projecting on the board at different rotation positions are fixed in a direction horizontal to the board position so that a focus of an image center is centered on the board. Take a picture with the matched CCD camera, set a processing unit that presumes the plane coordinates of the substrate in advance, and calculate the continuous coordinates of the virtual coordinate plane corresponding to the viewing angle of the lead wire of a predetermined length or more in the image pickup. Input to the processing unit, determine the areas other than the input coordinates as the lead wire non-existence area, and set the coordinate position other than the lead wire non-existence area remaining after the input processing at an appropriate substrate rotation angle to a predetermined length or more on the board. A lead wire position detecting method for a printed circuit board, characterized in that the position of the protruding lead wire end portion is specified. 2. A turntable for rotating a printed circuit board and a lead wire protruding on the circuit board at different rotational positions,
Taking a picture from the horizontal position of the board, and setting the CCD camera with the focus of the image center at the board center and the virtual plane coordinates corresponding to the board, and the viewing angle of the lead wire of a predetermined length or more in the shooting image In response to the input of continuous coordinates on the virtual coordinate plane corresponding to, it is determined that the area other than the input coordinates is the lead wire non-existing area, and the coordinate positions other than the lead wire non-existing area remaining after the input processing at an appropriate substrate rotation angle are A processing unit that identifies the position of the lead wire terminal portion protruding beyond a predetermined length on the substrate, a transport mechanism unit that transports the substrate from the turntable to the cutting processing table, and a processing unit that is installed on the cutting processing table and is installed from the processing unit. The automatic lead wire cutting device for a printed circuit board, which is configured by a cutting processing mechanism part that cuts a lead wire protruding portion at a predetermined position in accordance with the instruction.