Laser marker and method of light spot adjustment therefor

Claim 1

A laser marker comprising: a collimator lens converting laser light emitted from a broad area semiconductor laser into substantially parallel beams of light; a cylindrical concave lens permitting to pass therethrough the laser light having passed through the collimator lens and being perpendicular to a plane of an active layer of the semiconductor laser, the cylindrical concave lens serving as a concave lens for the laser light having passed through the collimator lens and being parallel to the plane of the active layer; a cylindrical convex lens permitting to pass therethrough the laser light having passed through the concave lens and being perpendicular to the plane of the active layer of the semiconductor laser, the cylindrical convex lens serving as a convex lens for the laser light having passed through the collimator lens and being parallel to the plane of the active layer; and a focusing lens focusing the laser light having passed through the cylindrical convex lens.

Claim 6

A method of light spot adjustment for a laser marker including a collimator lens converting laser light emitted from a broad area semiconductor laser into substantially parallel beams of light, a cylindrical concave lens permitting to pass therethrough the laser light having passed through the collimator lens and being perpendicular to a plane of an active layer of the semiconductor laser, the cylindrical concave lens serving as a concave lens for the laser light having passed through the collimator lens and being parallel to the plane of the active layer, a cylindrical convex lens permitting to pass therethrough the laser light having passed through the concave lens and being perpendicular to the plane of the active layer of the semiconductor laser, the cylindrical convex lens serving as a convex lens for the laser light having passed through the collimator lens and being parallel to the plane of the active layer, and a focusing lens focusing the laser light having passed through the cylindrical convex lens, the method comprising the step of: adjusting locations of the respective lenses so that incidence angles of the perpendicular laser light and the parallel laser light are equal to each other when the perpendicular laser light and the parallel laser light are equidistant from an optical axis, whereupon the laser light passing through the focusing lens is focused into a small light spot.

Claim 7

A method of light spot adjustment for a laser marker including a collimator lens converting laser light emitted from a broad area semiconductor laser into substantially parallel beams of light, a cylindrical concave lens permitting to pass therethrough the laser light having passed through the collimator lens and being perpendicular to a plane of an active layer of the semiconductor laser, the cylindrical concave lens serving as a concave lens for the laser light having passed through the collimator lens and being parallel to the plane of the active layer, a cylindrical convex lens permitting to pass therethrough the laser light having passed through the concave lens and being perpendicular to the plane of the active layer of the semiconductor laser, the cylindrical convex lens serving as a convex lens for the laser light having passed through the collimator lens and being parallel to the plane of the active layer, and a focusing lens focusing the laser light having passed through the cylindrical convex lens, the method comprising the step of: adjusting locations of the respective lenses so that incidence angles of the perpendicular laser light and the parallel laser light are equal to each other when the perpendicular laser light and the parallel laser light are equidistant from an optical axis, whereupon the laser light passing through the focusing lens is focused into a small light spot.