JP2565000B2 - Capacitor polarity inspection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor polarity inspection device, and more particularly to a capacitor polarity inspection device used for the polarity inspection of a tantalum capacitor mounted on a printed circuit board.

[0002]

2. Description of the Related Art A conventional capacitor polarity inspection device includes an illumination, a camera, a binarization circuit, a window generation circuit,
It is configured to include a measurement circuit and a determination circuit.

A conventional capacitor polarity inspection device will be described in detail with reference to the drawings. FIG. 3 is a block diagram showing a conventional example. The condenser polarity inspection device shown in FIG. 3 includes (A) an illumination 11 that illuminates the condenser 12 to be inspected with illumination light, and (B) a camera 13 that is attached above the condenser 12 and outputs a grayscale image signal a ( C) The grayscale image signal a is "1" corresponding to the bright part,
A binarization circuit 14 for converting the binarized image signal b of "0" corresponding to a dark part, (D) Generates an inspection window of a preset dimension in the binarized image signal b, and binarizes the window. Window generation circuit 35 for outputting the digitized image signal h, (E) measuring circuit 3 for measuring the area of "1" of the binarized image signal h in the window and outputting the in-window area signal i
6, (F) Based on the window area signal i, "1"
Compare the sum of the areas of and the preset area,
If the total sum of the areas of "1" is smaller, the determination circuit 37 that determines the polarity inversion is included.

FIGS. 4A and 4B are pattern diagrams showing the principle of the prior art. In FIG. 4A, the inspection window 42 is generated on the side of the polarity mark 41 of the capacitor 40 mounted in the normal direction. The polarity mark 41 is whiter than other parts, and by setting a binarization level between the brightness of the polarity mark 41 and the brightness of the other part, only the part of the polarity mark 41 becomes “1”, and the measurement circuit The area measured at 36 is almost the area of the polar mark 41.

In FIG. 4B, the inspection window 42a is generated in the direction opposite to the polarity mark 41a of the capacitor 40a mounted in the opposite direction. Inspection window 42a
There is no polarity mark 41a inside the inspection window 42a
The area of "1" is smaller than the area of "1" in the inspection window 42 generated in the normally mounted capacitor 40. Therefore, by setting the intermediate area of the area of "1" in the inspection window when mounted in the opposite direction from the case where it is normally mounted as the comparison target area in the determination circuit 37, Was being tested for polarity.

[0006]

The above-mentioned conventional capacitor polarity inspection device has a drawback that an erroneous determination is made when the polarity mark is faint. Also, if the comparison target area is set small so that even if the polarity mark is faint, it can be determined as normal mounting.If there is a display character etc. in the opposite direction even if it is mounted in the opposite direction, There was a drawback that it was erroneously determined to be normal mounting.

[0007]

The capacitor polarity inspection apparatus of the present invention comprises: (A) illumination for illuminating a capacitor to be inspected with illumination light; (B) mounted above the capacitor to output a grayscale image signal. A camera that performs (C) "1" corresponding to the bright and dark image signals
And a binarization circuit for converting into a "0" binarized image signal corresponding to a dark portion, (D) An inspection region having a size preset in the binarized image based on the binarized image signal. And a binarization image signal in the window is generated, and (E) an area of "1" for each label of the binarization image signal in the window is measured and an area signal for each label in the window is output. (F) Based on the label-based area signal in the window,
A detection circuit for detecting a label having the largest area of "1" and outputting a maximum label area signal, (G) comparing the maximum label area with a preset area based on the maximum label area signal, If the maximum label area is smaller, it is determined to be a defect.

[0008]

The present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. The condenser polarity inspection device shown in FIG. 1 is (A) an illumination 11 that illuminates the condenser 12 to be inspected with illumination light, and (B) a camera 13 that is attached above the condenser 12 and outputs a grayscale image signal a ( C) The grayscale image signal a is "1" corresponding to the bright part,
A binarization circuit 14 for converting the binarized image signal b of "0" corresponding to a dark portion, (D) An inspection area having a preset size for the binarized image based on the binarized image signal b. And a window generating circuit 1 for generating an in-window binary image signal c
5, (E) "1" for each label of the binarized image signal c in the window
Measuring circuit 16 which outputs the area signal d for each label in the window, and (F) based on the area signal d for each label in the window,
A detection circuit 17 which detects a label having the largest area of "1" and outputs a maximum label area signal e, (G) compares the maximum label area with a preset area based on the maximum label area signal e If the area of the maximum label is smaller, the determination circuit 18 for determining a defect is included.

2A and 2B are pattern diagrams showing the principle of the present invention. In FIG. 2A, the inspection window 22 is generated on the side of the polarity mark 21 of the capacitor 20 mounted in the normal direction. The polarity mark 21 is whiter than other parts, but the polarity mark 21 may be faint. Therefore, by setting a low binarization level at which other parts do not become “1”, Only the polar mark 21 portion and the display character 24 portion of the target fading portion 23 become "1". Therefore, the maximum label area detected by the detection circuit 17 is almost the area of the polar mark 21.

FIG. 2B shows the inspection window 2 in the direction opposite to the recess 21a of the capacitor 20a mounted in the opposite direction.
2a has been generated. The inspection window 22a has a portion of the display character 21a, but since the display characters are not connected to each other, a plurality of labels are present in the inspection window 22a. The maximum label area detected by the detection circuit 17 is the maximum label area 25 among the plurality of labels described above.
It will be only the area. As described above, since the maximum label area detected in the inspection window 22a generated in the capacitor 20a mounted in the opposite polarity direction is a part of the displayed characters, the inspection window 22 generated in the normally mounted capacitor 20 is displayed. It can be seen that it is always smaller than the maximum label area inside.

Therefore, by setting the intermediate area of the maximum label area in the inspection window when the mounting is performed in the opposite direction from the case where the mounting is performed normally, as the comparison target area in the determination circuit 18, Capable of inspecting the polarity of capacitors.

[0013]

According to the capacitor polarity inspection apparatus of the present invention, instead of performing the inspection by summing the areas of the white portions in the inspection window, the inspection is performed by the maximum area of the plurality of isolated white portions in the inspection window. Since this is performed, there is an effect that the polarity inspection can be performed without being affected by faint display characters and the presence of the display characters themselves.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

2A and 2B are pattern diagrams showing the principle of the present invention.

FIG. 3 is a block diagram showing a conventional example.

4A and 4B are pattern diagrams showing the principle of the conventional technique.

[Explanation of symbols]

 11 Illumination 12 Condenser 13 Camera 14 Binarization circuit 15 Window generation circuit 16 Measurement circuit 17 Detection circuit 18 Judgment circuit a Gray image signal b Binarized image signal c Binarized image signal in window d Area signal by label in window e Maximum label area signal

Claims (1)

(57) [Claims] 1. (A) Illumination for illuminating a condenser to be inspected with illumination light, (B) a camera mounted above the condenser and outputting a grayscale image signal, (C) a bright portion of the grayscale image signal Corresponding to "1"
And a binarization circuit for converting into a "0" binarized image signal corresponding to a dark portion, (D) An inspection region having a size preset in the binarized image based on the binarized image signal. And a binarization image signal in the window is generated, and (E) an area of "1" for each label of the binarization image signal in the window is measured and an area signal for each label in the window is output. (F) Based on the label-based area signal in the window,
A detection circuit for detecting a label having the largest area of "1" and outputting a maximum label area signal, (G) comparing the maximum label area with a preset area based on the maximum label area signal, A capacitor polarity inspecting device, comprising: a determination circuit for determining a defect when the maximum label area is smaller.