An ultraviolet irradiation device includes: a lamp house having at least one surface formed with a light extraction surface; an excimer lamp that is accommodated in the lamp house at a position apart from the light extraction surface in a first direction, the excimer lamp emitting ultraviolet light having a main emission wavelength belonging to a first wavelength band of 190 nm or more and 225 nm or less; a pair of electrodes that applies a voltage to a light-emitting tube of the excimer lamp; an optical filter disposed on the light extraction surface, and that substantially transmits the ultraviolet light having the first wavelength band and substantially fails to transmit ultraviolet light having a wavelength of 240 nm or more and 300 nm or less; and a light diffuser that is disposed between the excimer lamp and the optical filter in the lamp house in the first direction.

A light irradiation device according to an embodiment includes an excimer lamp including a light emitting tube emitting light, a first electrode disposed at an outer side of the light emitting tube, a second electrode disposed at an outer side of the light emitting tube in correspondence to the first electrode, and an auxiliary light emitting body disposed between the first electrode and the second electrode to emit light toward the light emitting tube when a voltage is applied to the first and second electrodes, and a case in which the excimer is provided and which has a contact point adjustment part configured to accommodate a portion of the auxiliary light emitting body.

An excimer lamp according to an embodiment of the present disclosure is capable of improving start-up characteristics and a light irradiation efficiency of a lamp and being miniaturized. The excimer lamp includes a light emitting tube emitting light, a first electrode disposed at an outer side of the light emitting tube, a second electrode disposed at an outer side of the light emitting tube in correspondence to the first electrode, and an auxiliary light emitting body disposed between the first electrode and the second electrode to emit light toward the light emitting tube when a voltage is applied to the first and second electrodes, and a light irradiation device having the same.

Provided is an ultraviolet irradiation device including an excimer lamp, a main emission wavelength of which belongs to a wavelength band of 190-230 nm (first wavelength band), the ultraviolet irradiation device that shows high startability. This ultraviolet irradiation device includes: a lamp house on at least one surface of which a light extraction surface is formed; an excimer lamp accommodated in the lamp house, the excimer lamp that emits ultraviolet light, a main emission wavelength of which belongs to a first wavelength band of 190-230 nm; and a start assist light source arranged in a position in which ultraviolet light, a main emission wavelength of which belongs to a second wavelength band of 250-300 nm, is capable of being irradiated to the excimer lamp.

A Far UV radiation system including a Far UV radiation source and a high pass filter. The high pass filter having a cutoff wavelength of 234 nm-237 nm when measured at an incidence angle of zero degrees and adapted to substantially reduce UV C radiation emitted from the Far UV radiation source so that the Far UV radiation system does not emit substantial UV radiation in wavelengths longer than 240 nm. The Far UV radiation system may be adapted to substantially reduce UV C, UV B, and UV A radiation from the Far UV radiation source.

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.

This application discloses an ultraviolet lamp with minimized ozone generation, the ultraviolet lamp comprising an outer tube; an inner tube arranged across the interior of the outer tube; an outer electrode installed on the outside wall of the outer tube; and an inner electrode installed on the inner side of the tube; wherein the outer electrode is in surface contact with the outside wall of the outer tube; and the width of the contact surface between the outer electrode and the outer tube is equal to the width of the effective electric field generated between the outer electrode and the inner electrode. Thus, because there is no discharge area between the outer electrode and the outer tube, when the outer electrode is connected to a high voltage, there is no discharge in the air, and no ozone is generated.

Provided is a bacteriostatic method for suppressing the proliferation of a bacterium while reducing the influence on a human body.

The bacteriostatic method is for suppressing a proliferation of a bacterium in a target region and includes a step (a) for irradiating the target region with ultraviolet light having a main peak wavelength of 200 nm to 230 nm inclusive at an average irradiance equal to or less than D.sub.Max (μW/cm.sup.2) defined by Formula (1):

D.sub.Max=9391.1×exp(−0.043λ)  (1) where λ is the main peak wavelength (nm).

An excimer lamp includes a plurality of arc tubes and an electrode pair. The electrode pair comprises a plurality of elongated electrode plates extending along a tube axis direction of the plurality of arc tubes. Each electrode plate comprises a polarity opposite that of an adjacent electrode plate (i.e., alternating polarities). The plurality of arc tubes and the plurality of electrode plates are disposed in an alternating side-by-side orientation such that an arc tube of the plurality of arc tubes is disposed between adjacent electrode plates of the plurality of electrode plates.

A ultraviolet irradiation apparatus includes: a first electrode block and a second electrode block located apart from each other in a first direction or located in an electrically-insulated state in the first direction; a recessed groove formed on a side surface of each of both the blocks; a first discharge lamp partially fitted into the recessed grooves formed in both the blocks and located across the both blocks; a power supply part for supplying electrical power to the first discharge lamp; a first current-carrying member electrically connecting the first electrode block and the power supply part; a second current-carrying member capable of electrically connecting the second electrode block and the power supply part at an electrical potential different from that of the first current-carrying member; and a light irradiation window for extracting ultraviolet light emitted from the first discharge lamp to outside.