Excimer lamp

Abstract

In the excimer lamp according to the present invention, a flat discharge vessel having a substantially rectangular cross-sectional shape and comprising a pair of planar parts and a pair of side-surface parts has a pair of external electrodes disposed on the respective outer surfaces of the planar parts. The end parts of the external electrodes are provided with an auxiliary electrode extending to a region that is made smaller than the distance between the planar parts. A lead that supplies electricity to the external electrode is connected to the auxiliary electrode in the region that is made smaller than the distance between the planar parts.

Claims

1. An excimer lamp comprising: a discharge vessel including a pair of plane face parts and a pair of side face parts and having a flat, substantially quadrilateral cross section; a pair of external electrodes each disposed on each of outer surfaces of the plane face parts of the discharge vessel; an auxiliary electrode extending from an end portion of the external electrode to a specific area where a thickness of the discharge vessel is smaller than a distance between the plane face parts; a lead connected to the auxiliary electrode in the specific area to supply power to the external electrode; and a light transmitting part equipped on at least one of the pair of external electrodes to pass through ultraviolet generated in the discharge vessel.

2. The excimer lamp according to claim 1, wherein the discharge vessel includes a glass tube having a flat, substantially quadrilateral cross section, and sealing members welded near an end portion of the glass tube, the glass tube includes a skirt part formed near the end portion of the glass tube with protruding out beyond the sealing member, and a concave part with a reduced thickness in the direction where the pair of external electrodes face each other, formed in a portion of the skirt part, the auxiliary electrode extends from the end portion of the external electrode to the concave part of the glass tube, and the lead is connected to the auxiliary electrode in the concave part of the glass tube.

3. The excimer lamp according to claim 1, wherein the discharge vessel includes a pinch seal part sealing the discharge vessel formed in an end portion of the discharge vessel, the auxiliary electrode extends from the end portion of the external electrode to the pinch seal part, and the lead is connected to the auxiliary electrode at the pinch seal part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is top plan view (A), a side view (B), and a perspective view (C) of a first embodiment of the present invention.

(2) FIG. 2 is a perspective part (A) and a partially cross-sectional side view (B) of a state where a lead is connected.

(3) FIG. 3 is a perspective view of a second embodiment of the present invention.

(4) FIG. 4 is a perspective part (A) and a partially cross-sectional side view (B) of a state where a lead is connected.

(5) FIG. 5 is a perspective view of a conventional excimer lamp.

(6) FIG. 6 is a perspective view (A) and a partially cross-sectional view (B) of a state where a lead is connected in a prior art example.

(7) FIG. 7 is a diagram explaining a problem with a conventional excimer lamp.

MODE FOR CARRYING OUT THE INVENTION

(8) FIG. 1 illustrates an excimer lamp 1 of the present invention, and FIG. 2 illustrates a state where a lead is connected. In FIG. 1 and FIG. 2, an exhaust tube (see FIG. 6) is omitted for the sake of avoiding complexity.

(9) The excimer lamp 1 includes a discharge vessel 2 having a flat, substantially quadrilateral cross section and including a pair of quadrilateral plane face parts 3, 3 and a pair of side face parts 4, 4 extending along side edges in the longitudinal direction of the plane face parts. As illustrated in FIG. 1(B), a pair of external electrodes 5, 5 are provided on outer surfaces of the plane face parts 3, 3 of this discharge vessel 2. A discharge space inside the discharge vessel 2 is sealed and filled with a discharge gas that contains a rare gas and a chloride gas. The rare gas is selected from krypton, xenon, and so on.

(10) The external electrodes 5, 5 may be formed on the outer surfaces of the plane face parts 3, 3 of the discharge vessel 2 by applying a metal paste such as gold paste, or by adhering a piece of transfer paper, for example. At least one of these external electrodes 5 is formed in a mesh form, for example, so as to have a light transmitting part. Ultraviolet generated in the discharge space is emitted through this light transmitting part.

(11) A solid electrode 6 is formed at one end of the external electrode 5.

(12) The cross-sectional shape of the discharge vessel 2 is not necessarily precisely a flat quadrilateral. Both or one of the plane face parts 3 and side face parts 4 may be slightly bulged outward, or concaved inward. Moreover, a trapezoidal shape or parallelogram may also be adopted. These shapes are herein collectively expressed as a substantially quadrilateral shape.

(13) In this first embodiment, the discharge vessel 2 includes a tubular glass tube 2a having a substantially flat quadrilateral cross section, and sealing members 2b each welded to near an end portion of the glass tube. The end portion of the glass tube 2a protrudes out beyond the sealing member 2b to form a skirt part 2c. Concave parts 8, 8 are formed in this skirt part 2c in the direction in which the external electrodes 5 are oriented oppositely.

(14) An auxiliary electrode 7 is connected to the external electrode 5 (solid electrode 6), and extends to the concave part 8.

(15) This auxiliary electrode 7 may be formed by printing, or by applying a conductive paste using a dispenser followed by drying.

(16) A lead 10 that supplies power to the external electrode 5 is connected to the auxiliary electrode 7 by welding with glass solder 11 or the like inside this concave part 8, as illustrated in FIG. 2. The glass solder 11 is preferably accommodated below the top of the concave part 8, i.e., below the plane face part 3.

(17) When attaching a lamp base such as the one illustrated in FIG. 6(B) to the end portion of the discharge vessel 2 having the configuration described above, the weld (glass solder) 11 does not come in the way so that the thickness of the lamp base can be minimized.

(18) FIG. 3 and FIG. 4 illustrate a second embodiment, wherein a pinch seal part 9 is formed by crushing the plane face parts 3 flat in an end portion of the discharge vessel 2. The pinch seal part 9 is formed by heating the end portion of the discharge vessel 2 to soften, and by compressing and crushing the end portion, and this hermetically seals the discharge vessel 2.

(19) The auxiliary electrode 7 is connected to the solid electrode 6 at the end of the external electrode 5 provided on the plane face part 3 of the discharge vessel 2. This auxiliary electrode 7 extends along the outer surface of the discharge vessel 2 to the pinch seal part 9.

(20) FIGS. 4 (A) and (B) illustrate the connection structure of the lead 10 that supplies power to the external electrode 5. The lead 10 is connected to the auxiliary electrode 7 by welding with glass solder 11 or the like on the pinch seal part 9.

(21) According to this embodiment, the lead 10 is welded to the auxiliary electrode 7 on the pinch seal part 9 so that the weld (glass solder) 11 does not protrude largely in the thickness direction between the plane face parts 3, 3 of the discharge vessel 2. In some cases, the glass solder may be accommodated within the thickness range, in which case the thickness of the lamp base (see FIG. 6(B)) to be attached to this end portion can be made smaller so that the thickness of the lamp base will not be much larger than the thickness between the plane face parts 3, 3.

(22) While the auxiliary electrode 7 is illustrated as narrower than the external electrode 5 in this embodiment, the auxiliary electrode 7 need not necessarily be narrower, and may have the same width, for example, as the external electrode 5.

(23) Moreover, the solid electrode 6, which is provided at the end of the external electrode 5 in the embodiment of FIG. 1 to FIG. 2 and in the embodiment of FIG. 3 to FIG. 4, may be omitted in an alternative structure.

(24) As described above, according to the present invention, an auxiliary electrode is provided to an end portion of the external electrode that is provided on a plane face part of the discharge vessel, and a lead is connected to the auxiliary electrode in a region where the distance between the external electrodes is reduced. Therefore, the lead and its weld do not protrude from the plane face part largely in the thickness direction, which provides the effect of preventing the lamp base that covers the lead and weld from protruding more than the thickness of the discharge vessel as much as possible.

DESCRIPTION OF REFERENCE SIGNS

(25) 1: Excimer lamp 2: Discharge vessel 2a: Glass tube 2b: Sealing member 2c: Skirt part 3: Plane face part 4: Side face part 5: External electrode 6: Solid electrode 7: Auxiliary electrode 8: Concave part 9: Pinch seal part 10: Lead 11: Solder (weld)