METAL CAP WITH RINGED PROJECTION TO BE WELDED TO STEM AND RINGED GROOVE PROVIDED IMMEDIATELY INSIDE OF RINGED PROJECTION AND OPTICAL DEVICE HAVING THE SAME

摘要

An optical device with a CAN package is disclosed, where the cap is resistance-welded to the stem without causing failures due to fragments by the welding flying within the package. The cap of the invention has a flange portion to be welded to the stem. The flange portion provides a ringed groove in addition to the ringed projection for the welding. The fragment due to the welding may be captured in the ringed groove and is prevented from flying within the package. The ringed groove and the ringed projection are simultaneously formed in the stamping to form the body portion of the cap.