Flash tubes for photographic use, in particular, a flash tube is adapted to provide a light output adapted to FP-sync, Flat Peak. The flash tube includes a length of glass tubing enclosing a gas for use in the flash tube, a cathode inside a first end part of glass tubing and an anode inside a second end part of glass tubing. The cathode includes an element that helps to ionize the gas that is wound around the cathode, such that a spark stream starts from the upper part of the cathode and is prevented from spreading down wards on the cathode and changing the arc length during the light output adapted to FP-sync.

Flash tubes for photographic use, in particular, a flash tube is adapted to provide a light output adapted to FP-sync, Flat Peak. The flash tube includes a length of glass tubing enclosing a gas for use in the flash tube, a cathode inside a first end part of glass tubing and an anode inside a second end part of glass tubing. The cathode includes an element that helps to ionize the gas that is wound around the cathode, such that a spark stream starts from the upper part of the cathode and is prevented from spreading down wards on the cathode and changing the arc length during the light output adapted to FP-sync.

A flash light source device includes: a flash lamp; a wiring board that is provided with a circuit configured to cause the flash lamp to emit light; a housing that is formed of a conductive material and accommodates the flash lamp and the wiring board; and an electromagnetic shield cable that includes a wire directly connected to the wiring board, an electromagnetic shield layer that covers the wire, and an insulating protective layer that covers the electromagnetic shield layer, and extends to the inside and outside of the housing through an opening formed in the housing. The electromagnetic shield layer is exposed at least at a part corresponding to the opening. The part corresponding to the opening in the electromagnetic shield layer is electrically connected to a part defining the opening in the housing.

A flash light source device includes: a flash lamp; a wiring board that is provided with a circuit configured to cause the flash lamp to emit light; a housing that is formed of a conductive material and accommodates the flash lamp and the wiring board; and an electromagnetic shield cable that includes a wire directly connected to the wiring board, an electromagnetic shield layer that covers the wire, and an insulating protective layer that covers the electromagnetic shield layer, and extends to the inside and outside of the housing through an opening formed in the housing. The electromagnetic shield layer is exposed at least at a part corresponding to the opening. The part corresponding to the opening in the electromagnetic shield layer is electrically connected to a part defining the opening in the housing.

In an example, a method of operating an ultraviolet (UV) light source includes providing a supply power to the UV light source, and activating, using the supply power, the UV light source to emit UV light during a series of activation cycles. The method also includes, during at least one activation cycle in the series, sensing the UV light emitted by the UV light source to measure an optical parameter of the UV light. The optical parameter is related to an antimicrobial efficacy of the UV light. The method further includes adjusting, based on the measured optical parameter, an electrical parameter of the supply power to maintain a target antimicrobial efficacy of the UV light over the series of activation cycles.

In an example, a method of operating an ultraviolet (UV) light source includes providing a supply power to the UV light source, and activating, using the supply power, the UV light source to emit UV light during a series of activation cycles. The method also includes, during at least one activation cycle in the series, sensing the UV light emitted by the UV light source to measure an optical parameter of the UV light. The optical parameter is related to an antimicrobial efficacy of the UV light. The method further includes adjusting, based on the measured optical parameter, an electrical parameter of the supply power to maintain a target antimicrobial efficacy of the UV light over the series of activation cycles.

In an example, a method of operating an ultraviolet (UV) light source includes providing a supply power to the UV light source, and activating, using the supply power, the UV light source to emit UV light during a series of activation cycles. The method also includes, during at least one activation cycle in the series, sensing the UV light emitted by the UV light source to measure an optical parameter of the UV light. The optical parameter is related to an antimicrobial efficacy of the UV light. The method further includes adjusting, based on the measured optical parameter, an electrical parameter of the supply power to maintain a target antimicrobial efficacy of the UV light over the series of activation cycles.

In an example, a method of operating an ultraviolet (UV) light source includes providing a supply power to the UV light source, and activating, using the supply power, the UV light source to emit UV light during a series of activation cycles. The method also includes, during at least one activation cycle in the series, sensing the UV light emitted by the UV light source to measure an optical parameter of the UV light. The optical parameter is related to an antimicrobial efficacy of the UV light. The method further includes adjusting, based on the measured optical parameter, an electrical parameter of the supply power to maintain a target antimicrobial efficacy of the UV light over the series of activation cycles.

A lighting device capable of performing satisfactory light emission control while suppressing a rise in the temperature of the lighting device irrespective of the attachment of an optical accessory. In the lighting device, an accessory detection section detects whether or not an optical accessory for color adjustment or light distribution angle adjustment is attached to a light emission section, and light emission performed by the light emission section is limited based on a result of detection performed by the accessory detection section.

The present technology provides a high-pressure sodium lamp lighting device that reduces occurrence of the acoustic resonance phenomenon. A high-pressure sodium lamp lighting device of one aspect of the present invention comprises a high-pressure sodium lamp of arc length AL within the scope of 142.8 mmAL167 mm. The lighting device also includes an electronic ballast configured to supply a high frequency AC voltage to the high-pressure sodium lamp. A lighting frequency of the electronic ballast is a frequency that avoids a first and a second acoustic resonance occurrence bands f1 kHz and f2 kHz determined based on equations from an arc tube inner diameter D mm of the high-pressure sodium lamp. The equation for f1 is a range of f1min to f1max=(7.4D+130) to (8.3D+156). The equation for f2 is a range of f2 min to f2max=(11.5D+200) to (10.0D+197).