JPH0682726B2 - Appearance inspection device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection apparatus capable of visual inspection of electronic parts such as ICs and transistors by imaging.

2. Description of the Related Art Conventionally, when recognizing lead pins of electronic parts such as ICs and transistors, the appearance inspection apparatus shown in FIGS. 4 and 5 has been used.

The conventional visual inspection device will be described below. Fourth
In the figure, 1 is an electronic component of an object to be inspected, 2 is a lead pin of the electronic component 1, 3 is an illumination source that illuminates the lead pin 2, and 4 is a line sensor camera that detects light reflected from the lead pin 2. is there. Also, FIG. 5 (a)
Reference numeral 5 is a line sensor area showing a range detected by the line sensor camera 4, and 6 is a light irradiation unit of the illumination source 3.

Next, the operation of the appearance inspection device configured as described above will be described. The light emitted from the illumination source 3 is the lead pin 2
The light reflected by the line sensor area 5 is received by the camera 4.

The output waveform T shown in FIG. 5B was obtained from the camera 4, and the lead pin pitch P, the number N of lead pins, and the lead pin width W were detected.

Problems to be Solved by the Invention In such a conventional configuration, since the recognition of the lead pin 2 is checked by the output waveform T shown in FIG. 5 (b), the defect of the lead outside bend or the inside bend of the DUT 1 is detected. Was difficult. Further, depending on the surface treatment state of the lead pin 2, in the case of a lead pin that has been subjected to gloss plating or dip soldering treatment, the surface of the lead pin is rounded, so most of the reflected light travels in a direction other than the line sensor camera 4, and the line sensor camera The amount of light received by 4 is reduced. Therefore, it becomes difficult to detect the lead pin pitch P and the lead pin width W. When a camera having a two-dimensional sensor is used instead of the line sensor camera 4, the lead pin is recognized as an image, so that the roundness of the lead pin is less affected and the lead pin pitch P and the lead pin width W can be detected. However, it has not been possible to detect a subtle outward bending or inward bending of the lead pin of the electronic component 1.

It is an object of the present invention to provide a visual inspection apparatus having a simple structure and capable of comprehensively inspecting lead pins such as lead pin pitch, lead pin width, number of lead pins, lead pin shape, lead pin inward bend, and outward bend.

Means for Solving the Problems In order to achieve this object, a visual inspection apparatus of the present invention provides a camera for imaging an object to be inspected, an illumination system for irradiating the object to be inspected, and reflected light from a lead pin to the camera. It has an image reflection plate that guides to, and an adjustment plate for adjusting the amount of light emitted from the illumination system, and recognizes the state of the inspection object.

With the above configuration, the image of the inspected object is captured by the camera, and the width, shape, and unevenness of the inspected object are detected to detect the contrast of the reflected image from the image reflection plate, thereby comprehensively checking the inspected object. You can recognize the appearance.

Embodiment FIG. 1 is a sectional side view of an appearance inspection apparatus according to an embodiment of the present invention. The device configuration will be described below.

7 is a two-dimensional sensor, such as a charge coupled device (CCD)
Camera using, 8 is a high-frequency fluorescent lamp light source, 9 is a light source 8
Light source cover attached in the vicinity, 10 is a rail cover,
Reference numeral 11 is a low-distortion image reflection plate, 12 is a holding plate that holds the image reflection plate 11 at a predetermined inclination angle, 13 is a conveyance rail for the object to be inspected, and 14 is an adjustment plate for the amount of light emitted from the light source 8.

The operation of this embodiment will be described below. The lead pin 2 is irradiated by the light source 8, and the amount of irradiation light is adjusted by the adjustment plate 14 of the amount of irradiation light that can be adjusted in the arrow A direction, and is guided to the camera 7 as the reflected light of the image reflection plate 11. As a result, this camera 7 detects the image of the upper surface of the lead pin 2 as a direct image and the image of the side surface of the lead pin 2 as a reflected image from the image reflecting plate 11. Based on the detected image, the lead pin pitch, width, and number are detected. Also, camera 7
When the image is recognized by the illumination optical path S and the image reflection plate 11
The mutual relation of the reflectance can be easily adjusted to an appropriate state by changing the position of the irradiation light amount adjusting plate 14 and changing the irradiation light amount. That is, the lead pin image displayed on the camera 7 slightly changes depending on the amount of light emitted and the reflectance of the image reflecting plate 11. Therefore, by changing the adjustment plate 14 in the direction of arrow A and adjusting the irradiation light amount,
It is possible to create a state in which the outer bend and the inner bend of the lead pin 2 are clearly displayed together. After adjusting the irradiation light amount adjusting plate 14 in this way, as shown in FIG. 2, the shape of the lead pin is the normal body 2a, the outer curved body 2b or the inner curved body 2c, and the object to be inspected 1 is positioned on the camera 7. As shown in the example of the recognition image diagram of FIG. 3, the lead pin image 15 in the inwardly bent state has a low light reflectance, so the reflected image is dark and the state is normal at the binarization level in the image processing. It can be recognized by comparing with the lead pin. Further, the lead pin image 16 in the outwardly bent state is similar to the comparative recognition of the lead pin image 15 in the inner bend, and the image reflector 11
It is also possible to directly recognize as image 16a without going through
By performing the image recognition process using the direct image 16a at the proper binarization level, it is possible to perform the inspection in two directions, and a highly accurate recognition process can be obtained.

In order to finely adjust the irradiation light amount, it is also effective to make the tip of the adjusting plate 14 a tapered surface 14a as shown by the broken line in FIG. Further, although the camera 7 using the two-dimensional sensor is used as the image sensor for picking up the image of the object to be inspected in the above embodiment, the camera 7 may be a camera using an image pickup tube or the like.

As described above, according to the present invention, since the irradiation light amount is adjusted by the irradiation light amount adjustment plate for the lead pin, and the reflection image is recognized through the image reflection plate, the light reflectance and the image reflection This has the effect that image recognition processing with high recognition accuracy can be performed in the mutual relationship of the plates.

[Brief description of drawings]

FIG. 1 is a side sectional view of a visual inspection apparatus according to an embodiment of the present invention, FIG. 2 is a side view of an object to be inspected in the same embodiment, and FIG. 3 is a recognition image projected on a monitor or the like in the same embodiment. FIG. 4 is a front view, FIG. 4 is a sectional side view of a conventional visual inspection apparatus, and FIG. 5 is a diagram for explaining an output waveform of a line sensor camera of the conventional visual inspection apparatus. 1 ... Object to be inspected, 7 ... Camera, 8 ... Light source, 11 ... Image reflector, 14 ... Irradiation light amount adjustment plate.

Claims (1)

[Claims] 1. An image reflector having a predetermined inclination angle, a camera for capturing an image of an object to be inspected through the image reflector, and an illumination system for irradiating the object to be inspected with an amount of light that can be captured by the camera. An external appearance inspection device having an adjusting plate for adjusting the amount of light emitted from the illumination system.