Abstract: A lens unit includes a first lens (2) and a second lens (3) housed in a holder (1) which may improve aberration. The first lens (2) is cylindrical having a top that functions as a lens (2a), and the second lens (3) is pressed into the cylindrical portion (2b) of the first lens (2) having a top in such a manner that the inner periphery of the cylindrical portion (2b) of the first lens (2) is pressed by the outer periphery of the second lens (3).

Abstract: A lens unit includes a lens holder having an opening and an inner wall, the lens having an optical axis passing through the opening, a first lens having an outer circumference, and arranged in the lens holder along the optical axis, a second lens having an outer circumference, and arranged in the lens holder along the optical axis, and three strut portions provided on the inner wall of the lens holder. The strut portions position the first lens and the second lens. The strut portions have surfaces facing the optical axis, respectively, the surfaces of the strut portions slanting with respect to the optical axis and contacting the outer circumference of the first lens and the outer circumference of the second lens. This lens unit has the lenses positioned accurately.

Abstract: This lens unit includes lens barrel (7) with through hole (6), first lens (8a) press-fitted into through-hole (6), first step (9a) catching an outer edge of first lens (8a) in through-hole (6), second lens (8b) press-fitted into through-hole (6) in a direction of an optical axis of first lens (8a), and second step (9b) catching an outer edge of second lens (8b) in through-hole (6). Second lens (8b) has a diameter larger than that of first lens (8a). Third step (10a) or a sloped portion broadening through hole from the first lens to the second lens is further provided.

Abstract: A sputtering apparatus includes paired targets 31 disposed in a vacuum chamber 30, substrate holder 33 disposed at a position nearly perpendicular to the paired target 31 and apart from a space formed by the paired targets 31, a plasma source 37 for generating reaction plasma by after-glow plasma in the vicinity of the substrate holder 33, and a lead-in pipe 38 which connects the plasma source 37 to the vacuum chamber 30. Since reaction plasma of after-glow plasma can be produced in the vicinity of the substrate holder 33, it is possible to form a thin film of compound close to bulk characteristics at a low substrate temperature without the film being damaged by plasma.

Abstract: The object of the present invention is to provide a lens unit with first lens (2) and second lens (3) housed in holder (1) which may improve the aberration. It comprises cylindrical holder (1), first lens (2) and second lens (3) housed in holder (1). First lens (2) is cylindrical having a top that functions as lens (2a), and second lens (3) is pressed into cylindrical portion (2b) of first lens (2) having a top in such manner that the inner periphery of cylindrical portion (2b) of first lens (2) is pressed by the outer periphery of second lens (3).

Abstract: A lens unit includes a lens holder having an opening and an inner wall, the lens having an optical axis passing through the opening, a first lens having a outer circumference, and arranged in the lens holder along the optical axis, a second lens having a outer circumference, and arranged in the lens holder along the optical axis, and three strut portions provided on the inner wall of the lens holder. The strut portions position the first lens and the second lens. The strut portions have surfaces facing the optical axis, respectively, the surfaces of the strut portions slanting with respect to the optical axis and contacting the outer circumferences of the first lens and the outer circumferences of the second lens. This lens unit have the lenses positioned accurately.

Abstract: It comprises paired targets 31 disposed in vacuum chamber 30, substrate holder 33 disposed at a position nearly perpendicular to the paired target 31 and apart from a space formed by the paired targets 31, plasma source 37 for generating reaction plasma by after-glow plasma in the vicinity of the substrate holder 33, and lead-in pipe 38 which connects the plasma source 37 to the vacuum chamber 30. Since reaction plasma of after-glow plasma can be produced in the vicinity of the substrate holder 33, it is possible to form a thin film of compound close to bulk characteristics at a low substrate temperature without being damaged by plasma.