Abstract: 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.

Abstract: 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.

Abstract: A flash discharge tube includes tungsten pins configuring a pair of discharge electrodes, and an envelope. The envelope includes a central region, serving as an alkali-free region, which is configured with an alkali-free glass except for quartz glass. The central region becomes in a high temperature state during a firing operation of the flash discharge tube. The central region is smaller than a maximum region enclosing a gas-tight space formed by hermetically sealing the pair of the discharge electrodes and is not smaller than a minimum region enclosing an arc-discharge space formed between the tungsten pins of the pair of the discharge electrodes. The alkali-free region contains either no alkali metal component or not larger than a predetermined amount of an alkali metal component. Then, a trigger electrode is disposed in the alkali-free region. This provides the flash discharge tube featuring a stable short-interval continuous-firing operation.

Abstract: A flash discharge tube includes tungsten pins configuring a pair of discharge electrodes, and an envelope. The envelope includes a central region, serving as an alkali-free region, which is configured with an alkali-free glass except for quartz glass. The central region becomes in a high temperature state during a firing operation of the flash discharge tube. The central region is smaller than a maximum region enclosing a gas-tight space formed by hermetically sealing the pair of the discharge electrodes and is not smaller than a minimum region enclosing an arc-discharge space formed between the tungsten pins of the pair of the discharge electrodes. The alkali-free region contains either no alkali metal component or not larger than a predetermined amount of an alkali metal component. Then, a trigger electrode is disposed in the alkali-free region. This provides the flash discharge tube featuring a stable short-interval continuous-firing operation.

Abstract: The orientation of fluorescent lamps is detected in a manufacturing method for a direct backlight unit that alternates orientations of adjacent fluorescent lamps. In a preparation step of the manufacturing method for the backlight unit of the present invention, a plurality of fluorescent lamps are prepared. In each of the fluorescent lamps, a length (a1) from a first sealed portion of a glass bulb (26) to a non-phosphor layer (32) area is shorter than a length (a2) from a second sealed portion to a non-phosphor layer (32) area (a1<a2). In a detection step, the difference between the lengths is detected with use of a sensor. In an installation step, the fluorescent lamps are arranged with use of the detection results so that the first and second ends alternate on a same side of a housing.

Abstract: The orientation of fluorescent lamps is detected in a manufacturing method for a direct backlight unit that alternates orientations of adjacent fluorescent lamps. In a preparation step of the manufacturing method for the backlight unit of the present invention, a plurality of fluorescent lamps are prepared. In each of the fluorescent lamps, a length (a1) from a first sealed portion of a glass bulb (26) to a non-phosphor layer (32) area is shorter than a length (a2) from a second sealed portion to a non-phosphor layer (32) area (a1<a2). In a detection step, the difference between the lengths is detected with use of a sensor. In an installation step, the fluorescent lamps are arranged with use of the detection results so that the first and second ends alternate on a same side of a housing.

Abstract: A low-pressure discharge lamp (1) is provided that includes a glass tube (2) having an inner diameter in a range of 1 to 5 mm and a pair of electrodes (3) disposed at end portions in the glass tube (2). The pair of electrodes (3) contain at least one transition metal selected from transition metals of Groups IV to VI. Mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube (2). A relationship between a cathode glow discharge density J and a composition index ? of the sealed rare gas of the low-pressure discharge lamp (1) satisfies the following expression ??J=I/(S·P2)?1.5? (where S represents an effective discharge surface area (mm2) of an electrode, I represents a RMS lamp current (mA), P represents a pressure (kPa) of a sealed rare gas, and ? represents a composition index of a sealed rare gas that is a constant expressed by ?=(90.5A+3.4N)×10?3 when a total of a composition ratio A of argon and a composition ratio N of neon is expressed by A+N=1).

Abstract: A low-pressure discharge lamp (1) is provided that includes a glass tube (2) having an inner diameter in a range of 1 to 5 mm and a pair of electrodes (3) disposed at end portions in the glass tube (2). The pair of electrodes (3) contain at least one transition metal selected from transition metals of Groups IV to VI. Mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube (2). A relationship between a cathode glow discharge density J and a composition index ? of the sealed rare gas of the low-pressure discharge lamp (1) satisfies the following expression ??J=I/(S·P2)?1.5? (where S represents an effective discharge surface area (mm2) of an electrode, I represents a RMS lamp current (mA), P represents a pressure (kPa) of a sealed rare gas, and ? represents a composition index of a sealed rare gas that is a constant expressed by ?=(90.5A+3.4N)×10?3 when a total of a composition ratio A of argon and a composition ratio N of neon is expressed by A+N=1).

Abstract: A low-pressure discharge lamp (1) is provided that includes a glass tube (2) having an inner diameter in a range of 1 to 5 mm and a pair of electrodes (3) disposed at end portions in the glass tube (2). The pair of electrodes (3) contain at least one transition metal selected from transition metals of Groups IV to VI. Mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube (2). A relationship between a cathode glow discharge density J and a composition index ? of the sealed rare gas of the low-pressure discharge lamp (1) satisfies the following expression ??J=I/(S·P2)?1.5? (where S represents an effective discharge surface area (mm2) of an electrode, I represents a RMS lamp current (mA), P represents a pressure (kPa) of a sealed rare gas, and ? represents a composition index of a sealed rare gas that is a constant expressed by ?=(90.5A+3.4N)×10?3 when a total of a composition ratio A of argon and a composition ratio N of neon is expressed by A+N=1).

Abstract: The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter D1 of 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter D2 of the cylinder electrode is preferably set at D1?0.4 [mm]?D2<D1.

Abstract: A low-pressure discharge lamp (1) is provided that includes a glass tube (2) having an inner diameter in a range of 1 to 5 mm and a pair of electrodes (3) disposed at end portions in the glass tube (2). The pair of electrodes (3) contain at least one transition metal selected from transition metals of Groups IV to VI. Mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube (2). A relationship between a cathode glow discharge density J and a composition index ? of the sealed rare gas of the low-pressure discharge lamp (1) satisfies the following expression ??J=I/(S·P2)?1.5? (where S represents an effective discharge surface area (mm2) of an electrode, I represents a RMS lamp current (mA), P represents a pressure (kPa) of a sealed rare gas, and ? represents a composition index of a sealed rare gas that is a constant expressed by ?=(90.5A+3.4N)×10?3 when a total of a composition ratio A of argon and a composition ratio N of neon is expressed by A+N=1).

Abstract: The present invention has an object to provide a cold-cathode discharge lamp which can suppress sputtering on a lead-in wire and reduce consumption of mercury so as to achieve a longer lifetime without increasing an amount of applied mercury. The cold-cathode discharge lamp of the present invention is characterized in that a lead-in wire connected to a cylindrical electrode in a lighting tube is made of a material same as a material that forms the cylindrical electrode. It is possible to suppress concentration negative glow discharge shifted to the lead-in wire and to allow the electrode to be covered with even negative glow discharge. Thus, it is possible to reduce mercury consumed by excessive sputtering on the outer surface of the internal lead-in wire and to achieve a longer lifetime of the cold-cathode discharge lamp.

Abstract: The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter D1 of 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter D2 of the cylinder electrode is preferably set at D1−0.4 [mm]≦D2<D1.

Abstract: The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter D1 of 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter D2 of the cylinder electrode is preferably set at D1−0.4 [mm]≦D2<D1.

Abstract: The present invention has an object to provide a cold-cathode discharge lamp which can suppress sputtering on a lead-in wire and reduce consumption of mercury so as to achieve a longer lifetime without increasing an amount of applied mercury. The cold-cathode discharge lamp of the present invention is characterized in that a lead-in wire connected to a cylindrical electrode in a lighting tube is made of a material same as a material that forms the cylindrical electrode. It is possible to suppress concentration negative glow discharge shifted to the lead-in wire and to allow the electrode to be covered with even negative glow discharge. Thus, it is possible to reduce mercury consumed by excessive sputtering on the outer surface of the internal lead-in wire and to achieve a longer lifetime of the cold-cathode discharge lamp.

Abstract: The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter D1 of 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter D2 of the cylinder electrode is preferably set at D1−0.4 [mm]≦D2<D1.