An excimer lamp includes a discharge vessel in which a rare gas and a halogen are enclosed. The excimer lamp also includes at least one first electrode and at least one second electrode for generating a dielectric barrier discharge inside the discharge vessel. The discharge vessel has a discharge forming region and a non-discharge region such that discharging takes place in the discharge forming region and no discharging takes place in the non-discharge region. The discharge forming region is formed between the first electrode(s) and the second electrode(s). The non-discharge region communicates with the discharge forming region. The excimer lamp satisfies a following equation:
(Vb×Ph)/Sd≥4.50
where Vb [mm.sup.3] represents a space volume inside the discharge vessel, Sd [mm.sup.2] represents an inner surface area of the discharge vessel in the discharge forming region, and Ph [Torr] represents a halogen-atoms partial pressure enclosed in the discharge vessel.

A device for emitting ultraviolet light includes at least one excimer lamp and a housing for the excimer lamp(s). Each excimer lamp has a discharge vessel filled with light-emitting gases, and a pair of first and second electrodes that are placed in contact with the discharge vessel and produce a dielectric barrier discharge inside the discharge vessel. The housing is made of an insulating and heat-resistant resin material. The housing is configured to house the excimer lamp(s), and has a light-emitting window that allows light with a center wavelength in a range from 200 nm to 230 nm emitted from the excimer lamp(s) to exit from the housing.

A light irradiation device according to an embodiment of the present disclosure has high light irradiation efficiency and cooling efficiency and can be reduced in size. The light irradiation device includes an excimer lamp including a light emitting tube that emits light, and a lamp electrode provided on an outside of the light emitting tube, and a case including a case body in which the excimer lamp is accommodated, a connection support provided at one side of the case body to be connected to the lamp electrode, and a case electrode provided at the other side of the case body to be in contact with a surface of the light emitting tube.

A device for emitting ultraviolet light includes at least one excimer lamp and a housing for the excimer lamp(s). Each excimer lamp has a discharge vessel filled with light-emitting gases, and a pair of first and second electrodes that are placed in contact with the discharge vessel and produce a dielectric barrier discharge inside the discharge vessel. The housing is made of an insulating and heat-resistant resin material. The housing is configured to house the excimer lamp(s), and has a light-emitting window that allows light with a center wavelength in a range from 200 nm to 230 nm emitted from the excimer lamp(s) to exit from the housing.

A triple tube type excimer lamp according to an embodiment of the present invention includes a discharge unit which includes an outer tube having an external electrode on an outer circumferential surface thereof, an inner tube having the same axis as the outer tube, inserted into the outer tube, and having an internal electrode on an inner surface thereof, and one pair of assembly tubes respectively disposed on both sides of the inner tube, and configured to generate light by discharge, a cover tube having a shape surrounding an outer side of the outer tube; and one pair of bases respectively coupled with the one pair of assembly tubes and respectively sealed with both ends of the cover tube.

A device for emitting ultraviolet light includes at least one excimer lamp and a housing for the excimer lamp(s). Each excimer lamp has a discharge vessel filled with light-emitting gases, and a pair of first and second electrodes that are placed in contact with the discharge vessel and produce a dielectric barrier discharge inside the discharge vessel. The housing is made of an insulating and heat-resistant resin material. The housing is configured to house the excimer lamp(s), and has a light-emitting window that allows light with a center wavelength in a range from 200 nm to 230 nm emitted from the excimer lamp(s) to exit from the housing.

An excimer lamp includes a discharge vessel in which a rare gas and a halogen are enclosed. The excimer lamp also includes at least one first electrode and at least one second electrode for generating a dielectric barrier discharge inside the discharge vessel. The discharge vessel has a discharge forming region and a non-discharge region such that discharging takes place in the discharge forming region and no discharging takes place in the non-discharge region. The discharge forming region is formed between the first electrode(s) and the second electrode(s). The non-discharge region communicates with the discharge forming region. The excimer lamp satisfies a following equation:

(Vb×Ph)/Sd≥4.50

where Vb [mm.sup.3] represents a space volume inside the discharge vessel, Sd [mm.sup.2] represents an inner surface area of the discharge vessel in the discharge forming region, and Ph [Torr] represents a halogen-atoms partial pressure enclosed in the discharge vessel.

A triple tube type excimer lamp according to an embodiment of the present invention includes a discharge unit which includes an outer tube having an external electrode on an outer circumferential surface thereof, an inner tube having the same axis as the outer tube, inserted into the outer tube, and having an internal electrode on an inner surface thereof, and one pair of assembly tubes respectively disposed on both sides of the inner tube, and configured to generate light by discharge, a cover tube having a shape surrounding an outer side of the outer tube; and one pair of bases respectively coupled with the one pair of assembly tubes and respectively sealed with both ends of the cover tube.

There are provided a glass tube in which a rare gas under predetermined pressure is sealed, a cathode electrode and an anode electrode disposed in a first end portion and a second end portion of the glass tube, respectively, facing each other, and a trigger electrode including a transparent conductive film formed on an outer peripheral surface of the glass tube. The trigger electrode includes an electrode body disposed on the outer peripheral surface of the glass tube, along a tube axis direction of the glass tube, and an enlarged portion that covers at least any one of the cathode electrode and the anode electrode, and that has a circumferential width wider than a circumferential width of the electrode body. This provides a flash discharge tube capable of reducing variations in optical distribution characteristics during light emission with a small amount of light, and improving life durability during continuous emission of a large amount of light and at short intervals.

There are provided a glass tube in which a rare gas under predetermined pressure is sealed, a cathode electrode and an anode electrode disposed in a first end portion and a second end portion of the glass tube, respectively, facing each other, and a trigger electrode including a transparent conductive film formed on an outer peripheral surface of the glass tube. The trigger electrode includes an electrode body disposed on the outer peripheral surface of the glass tube, along a tube axis direction of the glass tube, and an enlarged portion that covers at least any one of the cathode electrode and the anode electrode, and that has a circumferential width wider than a circumferential width of the electrode body. This provides a flash discharge tube capable of reducing variations in optical distribution characteristics during light emission with a small amount of light, and improving life durability during continuous emission of a large amount of light and at short intervals.