Abstract: A light source device includes a discharge tube, a discharge medium sealed inside the discharge tube, and inner and outer electrodes for exciting the discharge medium. The inner electrode is arranged inside the discharge tube. The outer electrode includes a first outer electrode and a second outer electrode that are connected electrically with each other. The first outer electrode is in contact with an outer surface of the discharge tube at a plurality of first contact portions that are located at different distances from the inner electrode and are provided discontinuously. The second outer electrode is in contact with the outer surface of the discharge tube at second contact portions. The second contact portions are arranged closer to the inner electrode than the first contact portions at a surface density greater than that of the first contact portions.

Abstract: A discharge lamp device which drives a discharge tube filled with a rare gas and has a first electrode mounted at the inside of the tube and a second electrode mounted at the outside of the tube. The lamp device includes a driving circuit that applies a voltage between the first and second electrodes. The driving circuit applies a positive rectangular wave voltage to the first electrode with a potential of the second electrode being a reference potential (0V) A backlight includes at least one discharge tube and the discharge lamp device.

Abstract: A light source device includes a substrate, a plurality of discharge tubes arranged on one principal surface of the substrate, a driving circuit mounted on the other principal surface of the substrate that is opposite to the foregoing principal surface, a discharge medium sealed in the discharge tubes, and first and second electrodes for exciting the discharge medium. The foregoing discharge medium does not contain mercury. Thus, the light source device can be formed smaller in size and thinner in thickness, and a liquid crystal display device employing the same can be provided.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside or outside the discharge tube, and the second electrode has a plurality of contact portions at which the second electrode is in contact with an outer surface of the discharge tube. The contact portions are located at different distances from the first electrode and are provided discontinuously. Thus, it is possible to provide a light source device with an improved light emission efficiency, and a liquid crystal display device in which the light source device is employed.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside or outside the discharge tube, and the second electrode has a plurality of contact portions at which the second electrode is in contact with an outer surface of the discharge tube. The contact portions are located at different distances from the first electrode and are provided discontinuously. Thus, it is possible to provide a light source device with an improved light emission efficiency, and a liquid crystal display device in which the light source device is employed.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside or outside the discharge tube, and the second electrode has a plurality of contact portions at which the second electrode is in contact with an outer surface of the discharge tube. The contact portions are located at different distances from the first electrode and are provided discontinuously. Xenon gas and at least one selected from argon gas and krypton gas are sealed in the discharge tube, in which the xenon gas accounts for 60 vol % to 80 vol %. Thus, it is possible to provide a light source device and a liquid crystal display device that provide light emission with high brightness and excellent brightness distribution and that can be manufactured readily.

Abstract: A ballast includes a rectangular wave generating circuit that generates a rectangular wave signal; a driving signal generating circuit supplied with the rectangular wave signal and a dimmer signal of a PWM waveform of a frequency lower than that of the rectangular wave signal and outputting a driving signal of an output obtained by extracting the rectangular wave signal for a period corresponding to “on” period of the dimmer signal; a pulse transformer which is supplied with a rectangular wave voltage based on the driving signal, step up the rectangular wave voltage and applying it to a discharge lamp. A rectangular wave reset circuit is provided so as to reset the generation of the rectangular wave signal at a rising of the dimmer signal. The driving signal generating circuit extracts the rectangular wave signal for a period starting from when the dimmer signal is turned on, until a time at which the dimmer signal and the rectangular wave signal are both off.

Abstract: A backlight device has a light guide plate, a rotary member, a rotary drive mechanism for rotating the rotary member, a plurality of mercury-free fluorescent lamps, and a power feed control mechanism. Each of the mercury-free fluorescent lamps has an arc tube mounted on the rotary member so as to extend parallel to the rotary shaft, a mercury-free discharge medium consisting of a rare gas sealed within the arc tube, and first and second electrodes for exciting the discharge medium. The mercury-free fluorescent lamps respectively emit lights of different colors. The emitted light enters the light guide plate through its light incident face and emerges from its light emission face.

Abstract: A ballast includes a rectangular wave generating circuit that generates a rectangular wave signal; a driving signal generating circuit supplied with the rectangular wave signal and a dimmer signal of a PWM waveform of a frequency lower than that of the rectangular wave signal and outputting a driving signal of an output obtained by extracting the rectangular wave signal for a period corresponding to “on” period of the dimmer signal; a pulse transformer which is supplied with a rectangular wave voltage based on the driving signal, step up the rectangular wave voltage and applying it to a discharge lamp. A rectangular wave reset circuit is provided so as to reset the generation of the rectangular wave signal at a rising of the dimmer signal. The driving signal generating circuit extracts the rectangular wave signal for a period starting from when the dimmer signal is turned on, until a time at which the dimmer signal and the rectangular wave signal are both off.

Abstract: A discharge lamp device which drives a discharge tube filled with a rare gas and has a first electrode mounted at the inside of the tube and a second electrode mounted at the outside of the tube, includes a driving circuit that applies a voltage between the first and second electrodes. The driving circuit applies a positive rectangular wave voltage to the first electrode with a potential of the second electrode being a reference potential (0V). A backlight includes at least one discharge tube and the discharge lamp device.

Abstract: A light source device includes a discharge tube, a discharge medium sealed inside the discharge tube, and inner and outer electrodes for exciting the discharge medium. The inner electrode is arranged inside the discharge tube. The outer electrode includes a first outer electrode and a second outer electrode that are connected electrically with each other. The first outer electrode is in contact with an outer surface of the discharge tube at a plurality of first contact portions that are located at different distances from the inner electrode and are provided discontinuously. The second outer electrode is in contact with the outer surface of the discharge tube at second contact portions. The second contact portions are arranged closer to the inner electrode than the first contact portions at a surface density greater than that of the first contact portions.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside or outside the discharge tube, and the second electrode has a plurality of contact portions at which the second electrode is in contact with an outer surface of the discharge tube. The contact portions are located at different distances from the first electrode and are provided discontinuously. Xenon gas and at least one selected from argon gas and krypton gas are sealed in the discharge tube, in which the xenon gas accounts for 60 vol % to 80 vol %. Thus, it is possible to provide a light source device and a liquid crystal display device that provide light emission with high brightness and excellent brightness distribution and that can be manufactured readily.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside the discharge tube. The second electrode is in contact with an outer surface of the discharge tube at a plurality of linear contact portions. The plurality of linear contact portions are substantially parallel with each other. Thus, a light source device is provided in which the occurrence of constricted discharge can be suppressed readily.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside or outside the discharge tube, and the second electrode has a plurality of contact portions at which the second electrode is in contact with an outer surface of the discharge tube. The contact portions are located at different distances from the first electrode and are provided discontinuously. Thus, it is possible to provide a light source device with an improved light emission efficiency, and a liquid crystal display device in which the light source device is employed.

Abstract: A light source device includes a substrate, a plurality of discharge tubes arranged on one principal surface of the substrate, a driving circuit mounted on the other principal surface of the substrate that is opposite to the foregoing principal surface, a discharge medium sealed in the discharge tubes, and first and second electrodes for exciting the discharge medium. The foregoing discharge medium does not contain mercury. Thus, the light source device can be formed smaller in size and thinner in thickness, and a liquid crystal display device employing the same can be provided.

Abstract: A fine particulate polishing agent is based on cerium oxide and silicon oxide; a slurry polishing agent comprises the foregoing fine particulate polishing agent which can be prepared by a method which comprises the steps of mixing, with stirring, cerium oxide fine particles, silica sol and a liquid; drying the mixture; mixing the material with a liquid; and then subjecting the mixture to deagglomeration using a wet pulverizing mill to give a slurry. Preferably, the dried particulate material is subjected to a thermal treatment at a high temperature of 150.degree. to 1200.degree. C., preferably 800.degree. to 900.degree. C., thereby to produce a solid solution of cerium oxide and silicon oxide. The slurry polishing agent can ensure the achievement of surface roughness comparable to or superior to that achieved by the colloidal silica polishing agents and a high polishing rate at least comparable to that achieved by the conventional cerium oxide polishing agents.