JPH0198076A - Pattern detecting device - Google Patents

Abstract

PURPOSE:To detect an accurate pattern of an object in simple and inexpensive constitution by extracting a feature part out of image pickup information and obtaining the pattern of the object from the extracted feature part. CONSTITUTION:An image pickup means 3 picks up the image of an area including a mold IC and transforms the image into image information. This image information is sent to a binarizing process part 8 of an image processing means via a control part 2. The part 8 binarizes the received image information and sends this to an image producing part 9. The part 9 produces a binarized image of an entire area based on binarized image data received from the part 8. The information on the binarized image is sent to a display part 7 via the part 2 and also to a pattern producing means 5. An arithmetic processing part 11 of the means 5 applies arithmetic processing to the receive binarized image based on a program stored in a program memory 10 and segments the pattern of the mold IC out of a background of a black level. Then the pattern of the mold IC is used for inspection of the external appearance.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is suitable for visual inspection of target objects such as packaged integrated circuit molds (hereinafter referred to as mold ICJ). The present invention relates to a pattern detection device.

(Prior Art) For example, a device shown in FIG. 10 is known as a device for detecting a pattern of a molded IC. That is, the molded IC 50 is stopped in a state in which it is in contact with the stopper pin 31 provided on the conveyance path 30, and the molded IC 50 in the stopped +h state is imaged by @imaging means (not shown) to obtain the pattern of the molded IC 50. It is designed to be used for visual inspection.

However, in such an apparatus, as shown in FIG.
If it is tilted to the opposite direction, it may protrude from the field of view of the imaging means, and there is a problem that accurate appearance inspection cannot be performed.

In addition, as a conventional device, as shown in FIG.
Place the positioning plates 32a, 32b, 32c, and 32d from all sides of the molded IC 50 at specific positions on the molded IC.
After contacting and positioning 50, this molded IC50
There is also known a device in which the external appearance is inspected by taking an image with an imaging means.

However, in the case of the device shown in FIG.
Although accurate positioning is possible, the positioning plate 32
There is a problem that the configurations of a to 32d are complicated and expensive.

(Problems to be Solved by the Invention) As described above, with the conventional apparatus, it is not possible to obtain an accurate pattern due to positional deviation of the target object, or the configuration for obtaining an accurate pattern is complicated. Another problem is that it is expensive.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a pattern detection device that can obtain an accurate pattern of a target object with a simple and inexpensive configuration even when the target object is inevitably misaligned. .

[Structure of the Invention] (Means for Solving the Problems) The pattern detection device of the present invention includes an imaging means for obtaining an image of a region including a target object, and an imaging means for determining an image of an object based on sleep image information obtained by the imaging means. an image information processing means for extracting a characteristic part of an object and separating information on a region to be inspected of the target object from other information based on the extracted characteristic part; and pattern creation means for determining a pattern of a target object based on information about the object.

(for production) The operation of the apparatus having the above configuration will be explained below.

The imaging means captures an image of a region including the target object whose pattern is to be detected. The image information processing means extracts a characteristic part from the imaging information obtained by the imaging means, and based on the extracted characteristic part, divides this into information on the area to be inspected of the target object information and other information. Separate into

The pattern creation means obtains a pattern of the target object based on information about the separated target object.

(Example) The present invention will be explained in detail below.

First, the present invention will be explained in detail with reference to FIGS. 7 and 8.

The basic principle of the present invention is to find the difference or feature between the target object and its background and determine the pattern of the target object based on this, rather than positioning the target object and determining its pattern as in conventional devices. It is.

That is, as shown in FIG. 7, a method called "projection" is used. This "projection" method creates a binary image with a black level rOJ and a white level "1" in a specific area E, scans this binary image in the X direction or Y direction, and scans the binary image with a white level "1". This is a method of adding up the number of points. A projection diagram (histogram) obtained from the binary image shown in FIG. 7 using this method is shown in FIG. 8(a). Then, a certain slice level is set for the projection diagram shown in FIG. 8(a), and "O" and "
1'', the boundary point coordinates of the binary image scale can be determined as shown in FIG. 8(b).

By finding such boundary point coordinates from the binary image of each part of the target object and determining the outline of the target object from a large number of boundary point coordinates, the pattern of the target object can be determined.

Next, the present invention based on the above principle will be explained in detail.

FIG. 1 shows the configuration of a device 1 of this embodiment, and this device 1 includes a control unit (CPLJ) 2 that performs overall control;
Based on the control of this control unit 2, an imaging means (for example, a CO
D camera) 3 and the imaging information obtained by the imaging means under the control of the control unit 2, and from this R image information, binarized image information separated into target object information and other background information is obtained. Based on the desired image processing means 4 and the control of the control section 2, the above 2.
Pattern creation means 5 that takes in digitized image information and creates a pattern of the target object based on this based on the principle described above.
, an input means (for example, a keyboard) 6 and a display means (for example, a CRT display) 7 connected to the control section 2.

The imaging means 3 is connected to a conveyance path 3 as shown in FIG. 2(a).
0, and a rectangular area S2 adjacent to this area S1, forming a part of the support base. .

The image processing means 4 processes the area S imaged by the imaging means 3.
A binarization processing unit 8 takes in the imaging information of area So and processes it into a binary value, and a binarization unit 8 creates a binarized image of area So from the binary data obtained by the binarization processing unit 8. The image forming section 9 includes an image creating section 9.

The pattern creating means 5 is shown in FIG. 9(a).

It is equipped with a program memory 10 that stores in advance a program for executing a series of processes shown in (b) and (c), and an arithmetic processing section 11 that executes arithmetic processing based on this program.

Note that the slice level for determining boundary points from a projection diagram, which will be described later, is set in advance in a program or by an input operation from the input unit 6.

The operation of the apparatus having the above structure will be explained below with reference to each explanatory diagram of FIGS. 2 to 6 and FIG. 9.

It is assumed that the molded IC 50, which is the target object, exists in the area So in a tilted state from the area S1 to the area S2, as shown in FIG. 2(a). Further, in the figure, 51 indicates a total of 14 leads arranged in rows on both sides of the molded IC 50.

First, the imaging means 3 takes an image of the area So including the molded IC 50 in the state shown in FIG. 2(a), and converts this into image information.

The control section 2 sends the image information to the binarization processing section 8.

The binarization processing section 8 converts all of the captured image information into binary values of black level "O" and white level "1", and converts this into binary values via the control section 2 to the binarization image creation section 9. send to At this time,
The approximately rectangular main body portion of the molded IC 50 and the 14 glue portions 51 have a white level of “1,” the boundary between areas S1 and S2 has a white level of “1,” and the area So
The remaining parts of
Perform value conversion.

The binarized image creation unit 9 creates a binarized image of the entire area So as shown in FIG. 2(a) based on each binarized image data sent from the binarization processing unit 8. create.

The image information of this binarized image is sent to the display unit 7 via the control unit 2.
The data is sent to the pattern generating means 5 and subjected to the processing described in detail below.

That is, the arithmetic processing unit 11 of the pattern creation means 5 converts the binarized image of the area So shown in FIG. 2(a) from the area S1 to the area So based on the program stored in the program memory 10. Set a projection area a, and take the projection of this projection area a in the X direction to determine the white level "1" that exists at the boundary between area S1 and area S2.
The position is determined and this is set as the transport path boundary (ST1).

Next, the arithmetic processing unit 11 creates a projection area b in area S2 as shown in FIG.
(ST2).

Roughly speaking, the arithmetic processing unit 11 takes a projection in the Y direction on the projection area b based on the program.

This state is shown in FIG. 3(a), and a projection diagram obtained by taking the projection is shown in FIG. 3(b).

Then, the arithmetic processing unit 11 sets a constant slice level for the projection diagram shown in FIG. 3(b), cuts the portion below the slice level, and creates a projection area as shown in FIG. 3(C). The position is determined based on the X coordinate and lead width of each lead 51 in b (ST3).

When the positions of the seven leads 51 are determined in this way, the center coordinates (Xl to X7) of each lead 51 are determined based on this.
> can also be determined, so the arithmetic processing unit 11 can determine, for example, between the center coordinates Xs and X7 as shown in FIG. 2(b), and
Projection area C (center coordinates X15+W1 or X?-W2, where Wl = W2
) is provided (Sr4), and the fourth
By taking a projection in the X direction as shown in the figure, a projection diagram of this projection area C shown in FIG. 5(a) is obtained, similar to the case described above. By setting a predetermined slice level for this projection diagram, as shown in FIG. seek.

A projection is taken between all the leads in the projection area b between each lead 51, a total of six boundary points are determined, and these are set as temporary boundary points (Sr5. SF3).

Next, since each temporary boundary point may deviate from the true boundary line of the molded IC 50 depending on the image quality of the binarized image, the arithmetic processing unit 11 calculates all the differences in the Y direction between adjacent temporary boundary points and Let the value be the slope of the boundary line of mold IC50 (
Sr7.5T8). Roughly speaking, the arithmetic processing unit 11 calculates the average value of each slope calculated in steps 7 and 8 (Sr
9) Exclude values of temporary boundary points that deviate significantly from the average value (STIO).

Next, the calculation processing unit 11 calculates a second average value using only the values of the remaining temporary boundary points (STII), and uses this second average value as the slope of the true boundary line. Equivalent temporary boundary points are selected (ST12).

The arithmetic processing unit 11 selects the rightmost point and the leftmost point from among the selected temporary boundary points (5T13), and substitutes the values of these two points into the equation for calculating a straight line to calculate the true value of the molded IC 50 to be formed in the projection area b. Find the slope and Y-intercept of and determine the boundary line A shown in FIG. 6 (ST14°8-15).

Furthermore, the calculation unit 11 determines the boundaries B, C, and D of the molded IC 50 in the same manner as described above (ST15), and then determines the four boundaries A, B, and C.

From the value of D, each of the intersections α, β, γ, and δ shown in FIG. 6 is determined from the formula for determining the intersection of two straight lines.

As a result, the pattern of the molded IC 50 is formed at the intersections α and β.
, T, and δ, and has been cut out from the background of the black level rOJ, and the pattern of this molded IC 50 will be subjected to visual inspection.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

For example, the process of taking projections between each lead of a molded IC may be performed over all of the leads as in the above-described embodiment, or may be performed by appropriately thinning out projections depending on the number of leads.

Roughly speaking, in the above-mentioned embodiment, the molded IC is approximately rectangular.
Although the description has been given above, the present invention can be similarly applied to molded ICs in which other parts are partially cut out.

[Effects of the Invention] According to the present invention described in detail above, the pattern of the target object can be obtained by simply placing the target object within the imaging field of the imaging means, regardless of the arrangement of the target object, which is simple and It is possible to provide a pattern detection device that can accurately detect patterns despite having an inexpensive configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a device according to an embodiment of the present invention, FIG. 2(a) is an explanatory diagram for taking projections of a target object in the same device, and FIG. 2(b) is a block diagram showing each target object in the same device. FIG. 3(a) is an explanatory diagram when taking a projection between leads. FIG. 3(a) is an explanatory diagram when taking a projection onto projection area b shown in FIG. 2(a). FIG. ), Figure 3 <C> is a binarized diagram of each lead determined based on Figure 3(b), and Figure 4 shows the projection to projection area C. FIG. 5(b) is a binary diagram corresponding to FIG. 5(a), FIG. Figure 7 is a principle explanatory diagram showing the binarized image and the projection direction, and Figure 8 (a>
is a projection view corresponding to Fig. 7, and Fig. 8(b) is a projection view corresponding to Fig. 8(a).
), Figure 9 (a), (b), (C)
10 is a schematic plan view showing an example of a conventional device, and FIG. 11 is a schematic plan view showing the other side of the conventional device. 1... Pattern detection device, 3... Imaging means, 4...
- Image processing means, 5... pattern creation means. Figure 1, Figure 3, Figure 4, Figure 5, Figure 6, and Figure 11.

Claims (3)

[Claims] (1) imaging means for obtaining an image of a region including the target object;
Image information processing that extracts characteristic parts of the target object based on the imaging information obtained by this imaging means, and separates information on the area to be inspected of the target object from other information based on the extracted characteristic parts. 1. A pattern detection device comprising: a pattern detection device; and a pattern creation device that obtains a pattern of a target object based on information about the target object obtained by the image information processing device. (2) The pattern detection device according to claim 1, wherein the information processing by the image information processing means is a binarization process. (3) The pattern creation of the target object by the pattern creation means includes a process of creating boundary points of the target object based on the target object information and a process of creating a boundary line from the created boundary points. The pattern detection device according to item 1.