Abstract: In an apparatus for producing a spark plug, approach driving conditions are calculated on the basis of a specified thrust feeding amount so that, while a temporal overlap occurs between a time period of feed-driving toward a rolling position P2 of a workpiece supporting portion (11) and an approach driving time period, in a circumferential direction of a workpiece W, a positional relationship between the starting position of the threaded portion which is rolling-formed, and the joining position of the ground electrode to the tip end face of the workpiece W is constant. The operation of an approach driving portion is controlled on the basis of the calculated approach driving conditions.

Abstract: In an apparatus for producing a spark plug, approach driving conditions are calculated on the basis of a specified thrust feeding amount so that, while a temporal overlap occurs between a time period of feed-driving toward a rolling position P2 of a workpiece supporting portion (11) and an approach driving time period, in a circumferential direction of a workpiece W, a positional relationship between the starting position of the threaded portion which is rolling-formed, and the joining position of the ground electrode to the tip end face of the workpiece W is constant. The operation of an approach driving portion is controlled on the basis of the calculated approach driving conditions.

Abstract: An inspection beam such as laser beam is scanned two-dimensionally on an inspection surface of a circuit board with a plurality of lands while allowing its reflected beam from the inspection surface to be received by a beam receiving section. The beam receiving section is formed by a device, such as a semiconductor position sensitive detector, which is capable of producing an output which varies according to a reflected beam brightness and reflected beam receiving position (which reflects the height level of the reflection surface). On the basis of the output of the beam receiving section, reflected beam brightness information and height level information at respective positions on the inspection surface are prepared. From the reflected beam brightness information at the respective positions, an existing region of each of the lands on the inspection surface can be fixed.

Abstract: An inspection beam is cast onto an inspection surface of a bump-attached circuit board, which inspection surface is provided with a plurality of solder bumps, and scanned within the inspection surface two-dimensionally while allowing its reflected beam to be received at PSD (Position Sensing Device). On the basis of detection output from a beam receiving section at that moment, information on heights at respective positions within the inspection surface and information on the brightness of the reflected beam are prepared. On the basis of the prepared reflected beam brightness information, an existing region of a top face of each bump (bump top face existing region) is fixed. By using information on height of each bump which is prepared on the basis of the information on the size or area of the bump top face existing region and the respective heights within the bump top face existing region, information on volume of each bump is prepared.