Abstract: A liquid discharge head includes a nozzle plate, a housing, a channel, and a positioning member. The nozzle plate has a nozzle hole and a first positioning hole penetrating through the nozzle plate in a thickness direction of the nozzle plate. The housing is bonded to the nozzle plate to form a single bonded body and has a second positioning hole extending in a thickness direction of the housing. A liquid flows through the channel between the nozzle plate and the housing to the nozzle hole. The positioning member fits into the first positioning hole and the second positioning hole to position the nozzle plate relative to the housing. A length of the positioning member is smaller than a sum of a length of the first positioning hole and a length of the second positioning hole in the thickness direction of the nozzle plate, and larger than the length of the second positioning hole.

Abstract: A semiconductor laser device includes a semiconductor layer that includes a light emitting region having a first width and a pad region formed in a region outside the light emitting region and having a second width exceeding the first width, an insulating layer that covers the light emitting region and the pad region, and a wiring electrode that has an internal connection region penetrating through the insulating layer and electrically connected to the light emitting region and an external connection region that covers the pad region across the insulating layer and is to be externally connected to a lead wire.