Abstract: A coil unit may include an even number of coils comprising a first coil and a second coil; and a coil holding member which holds the even number of the coils. An outer peripheral face of the coil holding member may include a side-face pair comprising a first side face and a second side face which are substantially parallel to each other. The first side face may be formed with a first protruded part around which the first coil is wound, the first protruded part being protruded to an outer peripheral side with respect to the coil holding member. The second side face may be formed with a second protruded part around which the second coil is wound, the second protruded part being protruded to an outer peripheral side with respect to the coil holding member. The first coil and the second coil may be structured from one conducting wire.

Abstract: A welded structure may include a first member having a spherical surface part, and a second member which is formed in a plate shape. A part of an end face of the second member before laser welding is performed is formed to be a contact end face having a contact part with which a part of the spherical surface part is contacted. The second member is formed with a joining part including the contact end face and the joining part is joined to the spherical surface part by laser welding. At least before laser welding is performed, a plate thickness of the joining part is thinner than a plate thickness of a portion of the second member except the joining part and the spherical surface part of the first member and the end part of the second member are joined to each other by laser welding.

Abstract: An optical unit may include a movable body holding an optical element; a fixed body surrounding the movable body; a plate-shaped spring member with a fixed body side connection part, a movable body side connection part, and an arm part which connects the fixed body side connection part with the movable body side connection part; and a drive mechanism to displace the movable body. The cover may be provided with a side plate part. The fixed body side connection part may include a frame part; and a plurality of protruded parts protruded from the frame part. The protruded parts may be separately provided from each other for every welding portion and an entire tip end side of the protruded part is formed as a melted part by welding.