Abstract: In an ignition device for an internal combustion engine which is mounted in a cylinder head in a state where a spark plug and an ignition coil are integrated with each other, the plug side tube section is made of ceramics and internally accommodates a center electrode and the coil side tube section is made of ceramics, with one of a primary winding and a secondary winding being wound around the coil side tube section. The plug side tube section and the coil side tube section are constructed as separate bodies and then combined with each other. This shortens the overall lengths of both the tube sections, thus preventing the occurrence of cracks or bends at calcining and improving the dimension accuracy after the calcining.

Abstract: An insulator includes a coil side cylindrical portion extending from a plug side cylinder portion in a direction departing from a combustion chamber. One end of the coil side cylindrical portion protrudes in the direction departing from the combustion chamber with respect to a primary winding and a secondary winding. A pressure sensing element is disposed next to the one end of the coil side cylindrical portion. The signal lines of the pressure sensing element are taken out of a casing without passing aside an ignition coil. Thus, the diameter of the casing does not increase. The output signal of the pressure sensing element is not adversely influenced by discharge noises generated from the ignition coil.

Abstract: In an ignition device for use in an internal combustion engine in which a spark plug and an ignition coil are integrated with each other and mounted in a cylinder head, a case is made of an electrical conductive material and one end portion of a secondary winding of the ignition coil is electrically connected to a center electrode of the spark plug while the other end portion of the secondary winding and an earth electrode of the spark plug are electrically connected to the case. Thus, the low-voltage side of the secondary winding and the earth electrode are electrically connected to each other through the case. This eliminates the need for a connector terminal and a wire harness for the electrical connection of the low-voltage side of the secondary winding to the internal combustion engine.

Abstract: An insulator includes a plug side cylindrical portion having an inner space for accommodating a center electrode and a coil side cylindrical portion extending in a direction departing from a combustion chamber. The high-voltage portion of an ignition coil is entirely accommodated inside the coil side cylindrical portion. According to this arrangement, the coil side cylindrical portion can assure insulation between the high-voltage portion and the low-voltage portion. The portion to be insulated and fixed by an insulating resin is limited only to the secondary winding.

Abstract: A spark plug fabricating method and a spark plug fabricated by the same are provided. The spark plug is equipped with a piezoelectric sensor working to measure the pressure of combustion of fuel in an engine and required to apply a given preload to the piezoelectric sensor at all the time. The piezoelectric sensor is disposed within a holder and retained between the holder and a porcelain insulator. The fabrication method includes the steps of pressing the holder to apply a required preload to the piezoelectric sensor in a longitudinal direction of the porcelain insulator and joining the holder to a metal shell while maintaining the preload applied to the piezoelectric sensor as it is.

Abstract: An improved structure of a spark plug is provided which consists of a center electrode retained within a metal shell and a ground electrode including a noble metal-made tip and a body joined to the metal shell. The noble metal-made tip is connected to the body through a fused portion that is a weld between the body and the noble metal-made tip and extends toward the center electrode to define a spark gap.

Abstract: A ground electrode has a proximal portion fixed to one end of a metallic housing and a distal portion extending toward one end of a center electrode so that an acute angle is formed between a center electrode axis and an axis of the distal portion of the ground electrode. A columnar ground electrode tip is fixed to a ground electrode end surface. The ground electrode tip protrudes from the ground electrode end surface and extends toward the center electrode along an axis crossing with an axis passing the ground electrode end surface. An axis of the center electrode tip is in a cross or skew relationship with an axis of the ground electrode tip.

Abstract: A hybrid IC of electronic circuit for a discharge lamp is disposed on the bottom of a metal case. A transformer, an inductor, a transformer, and a capacitor are disposed in a resin case. The resin case is contained in a metal case. In this instance, the transformer, the inductor, the transformer, and the capacitor are located outside the outer periphery of the IC so that the IC does not overlap on the transformer and other components. The transformer for a starter circuit has a secondary winding the inductance of which is 2.5 mH or larger, and a capacitance of a smoothing capacitor of a DC—DC converter is 0.5 &mgr;F or smaller. The switching frequency f of a MOS transistor is selected so that L2×C1 is equal to or larger than 1×10−1×f−1.68.

Abstract: In a discharge lamp lighting apparatus for a discharge lamp, each circuit component including a starter transformer is assembled to a bus bar casing, and a high voltage terminal of the starter transformer is connected to one end of a connecting terminal. The bus bar casing is adhesive-cemented to a metal base to which a HIC is attached. Then, a sealing resin fills the bus bar casing to seal the starter transformer and the HIC with the sealing resin. After the sealing resin solidifies, the other end of the connecting terminal and an output cable are connected, and subsequently a resin cover is assembled to the metal base. A shielding sheath covering the output cable is fixed to the bus bar casing by a clip. A ground connection part of the bus bar connectable to the ground side of an electric power source is shaped to protrude from the bus bar casing. The cover, the clip, the ground connection part and the base are ground-connected by a thread.

Abstract: In a discharge lamp device, the electric power supplied to a discharge lamp is controlled in order of first to fourth control regions from the start of lighting of the discharge lamp. In the first control region, the lamp current is held constant until the lamp voltage reaches a first voltage value. In the second control region, the lamp current is reduced so as to have a correlation with a first time constant curve for a constant time after the lamp voltage reaches the first voltage value. In the third control region, the lamp current is reduced so as to have a correlation with a second time constant curve after a lapse of the constant time. The second time constant curve differs from the first time constant curve.

Abstract: A light source assembly has a housing and a bulb unit disposed in the housing. The housing is made of an electromagnetic shielding material. The bulb unit is composed of a reflector made of an insulating material, a bulb accommodated in the reflector, a connector connecting the bulb to a control circuit and fixing it to the reflector and light transmitting windows formed in the reflector. The bulb is disposed in the reflector so as to cross the axis of the light transmitting windows. The connector projects to the outside from the reflector to be coupled or decouple with a connector of the control circuit.

Abstract: A lighting fixture apparatus for a vehicle is disclosed wherein both left and right side lighting fixtures or lamps may not be extinguished simultaneously and maintain a necessary function even if a light source extinguishes due to malfunction of the light source or its control circuit. Two optical transmission devices are provided each of which has a light source, two optical cables connected to both sides of the light source, and flat and hot zone luminous intensity distribution lenses connected to both ends of the two optical cables. The flat and hot zone luminous intensity distribution lenses are distributed to both the head lamps. An illuminating range obtained by combining illuminating ranges wherein both the lenses mounted on one of the optical transmission devices illuminate is similar to an illuminating range obtained by combining illuminating ranges wherein both the lenses mounted on the other optical transmission device illuminate.