| 摘要 |
<p>A method for manufacturing a spark plug, which includes photographing a spark gap as to detect the edges of a center and ground electrode and performing a predetermined treatment on the basis of image information obtained from the photographing step. Also disclosed is an apparatus for carrying out the method. In performing the photographing step, an illumination device 200 is disposed opposite a tip portion of a spark plug, in which a spark gap is to be formed, such that illumination rays pass through the spark gap. A camera 4, which is disposed opposite the illumination device 200 with respect to the tip portion of the spark plug, photographs the spark gap formed between a center electrode W 1 and a ground electrode W 2 . In relation to the photographing step, light shields 203 are disposed between a light source 201 of the illumination device (illumination means) 200 and the tip portion of the spark plug to block illumination rays directed toward the tip portion of the spark plug from the light source 201 but which diverge from the spark gap.</p> |
