Abstract: A method of manufacturing a spark plug cap covering a spark plug for an internal combustion engine, equipped with an ignition voltage detective capacitor having a first conductor housed in a cap body for carrying an ignition voltage produced by an ignition coil to the spark plug and a second conductor located keeping a predetermined distance from the first conductor while sandwiching an insulative material such that the capacitor is formed between the first and second conductors for detecting the ignition voltage. The method comprises separately fabricating said insulative body and a member from the insulative material embedding said second conductor therein and fixing the member at said insulative body such that said detective capacitor is formed. The second conductor may be formed in the shape of a plate to be wound around the cap body.

Abstract: A misfire-detecting system for an internal combustion engine compares detected sparking voltage with a first predetermined comparative level and a second predetermined comparative level lower than the first predetermined comparative level. Whether a misfire has occurred in the engine is determined based upon a logical relationship between results of the comparisons. As a result, a misfire can be detected accurately even when dielectric breakdown of the mixture occurs while a misfire has occurred.

Abstract: A misfire-detecting system for an internal combustion engine having a plurality of cylinders. A rotational speed of the engine is detected and a rotational speed signal indicative of the detected rotational speed of the engine is output. The rotational speed signal is filtered. Occurrence of a misfire in the engine is determined based on the filtered rotational speed signal.

Abstract: An ignition distributor cap having a first capacitor for detecting ignition voltage of a spark-ignition internal combustion engine to determine if misfire occurs. The ignition distributor cap has a coil contact tower connected to the secondary winding of an ignition coil of the engine, spark plug terminals connected to spark plugs of the engine, and a rotor connecting the coil contact tower to one of the spark plug terminals with a gap to generate an electric path carrying ignition voltage current produced at the ignition coil to the spark plug. In the ignition distributor cap, a conductor is located around the electric path keeping a predetermined distance from the electric path and forming a first capacitor such that the first capacitor constitutes a capacitive divider with a second capacitor for ignition voltage detection between the electric path and the conductor positioned at the coil contact tower or the individual spark plug terminals.

Abstract: A misfire-detecting system for an internal combustion engine in which a value of sparking voltage is detected, which is generated across a spare plug when high voltage is generated by an ignition device in response to generation of an ignition command signal. When a time period over which the detected value of sparking voltage exceeds a predetermined reference voltage value exceeds a predetermined time period value, the system determines that a misfire has occurred in the engine. A recharging command signal is generated for applying high voltage to the spark plug, after generation of the ignition command signal. As a result, a misfire can be accurately detected.

Abstract: A spark plug cap having a capacitor for detecting ignition voltage of an internal combustion engine to determine if misfire occurs. The spark plug cap covers the terminal of a spark plug and has a conductor for carrying ignition voltage current from an ignition coil to spark plug terminals to generate an electronic spark between spark plug electrodes and an insulator surrounding the conductor. In the spark plug cap, a second conductor is located around the first conductor keeping a predetermined distance from the first conductor such that a capacitor, which constitutes a capacitance divider with a capacitor for ignition voltage detection, is formed between the first and the second conductors. A ceramic insulator may be positioned between the first and the second conductors to provide higher insulation property.

Abstract: A fuel supply control system which controls an amount of fuel supplied to an internal combustion engine. An ECU detects a value related to an amount of combustion ions generated within cylinders. The detected value is compared with a predetermined value, and the amount of fuel supplied to the engine is corrected based upon the comparison result, when the engine is in a transient operating condition, such as acceleration and deceleration, whereby the responsiveness of the air-fuel ratio feedback control is enhanced to improve drivability and exhaust emission characteristics.

Abstract: A high tension cord cover disposed at an engine cylinder head for covering a groove in which high tension cords pass through for supplying an ignition voltage current to a spark plug of the engine. The cover is made of an insulation material and having a cord retaining section at the bottom surface facing the groove for retaining the cords in parallel with each other. A plate like conductor is embedded in the cover keeping a predetermined distance therefrom and sandwiching a portion of the insulation cover, whereby a capacitor, which constitutes a capacitive divider in cooperation with a second capacitor for detecting misfire through the ignition voltage, is formed between the conductive cores of the high tension cords and the plate like conductor. The conductor can be electrically shielded. A second member made of an insulation material can be provided in the groove underneath the cover for retaining the cords such that the conductor embedded in the cover is kept the predetermined distance from the cords.

Abstract: A misfire-detecting system detects a misfire occurring in an internal combustion engine. A value of sparking voltage for discharging a spark plug of the engine is detected. A differentiating circuit differentiates the detected value of the sparking voltage. A misfire-determining circuit compares the differential value of the sparking voltage with a predetermined value, and determines, based upon a result of the comparison, whether a misfire has occurred in the engine.

Abstract: A misfire-detecting system for an internal combustion engine carries out self-diagnosis of the system. In the system, sparking voltage generated across a spark plug of a cylinder of the engine is detected, and the detected sparking voltage is compared with a first predetermined reference voltage value, and a time period is measured over which the detected sparking voltage exceeds the first predetermined reference voltage value. It is determined that a misfire occurred in the engine when the measured time period exceeds a predetermined time period value. It is determined whether the engine is in self-sustaining operation. When it is determined that the engine is in self-sustaining operation, it is determined whether the misfire-detecting system is abnormal. It is determined that the misfire-detecting system is abnormal when the detected sparking voltage is lower than a second reference voltage value.

Abstract: A misfire-detecting system for an internal combustion engine detects a value of the sparking voltage generated by the igniting device after generation of the ignition command signal, determines the duration of a discharge of a spark plug, based upon the detected sparking voltage, and determines whether or not a misfire has occurred in the engine, based upon the determined duration of the discharge. For example, the misfire-detecting system measures the duration of the discharge from the time of generation of the ignition command signal, based upon the detected sparking voltage, compares the measured duration of the discharge with a predetermined time period. When the measured duration is shorter than the predetermined time period, it is determined that a misfire has occurred in the engine.

Abstract: A misfire-detecting system for an internal combustion engine detects values of operating parameters of the engine, determines ignition timing of the engine, based upon detected values of operating parameters of the engine to generate an ignition command signal indicative of the determined ignition timing, generates high voltage for causing generation of sparking voltage across a spark plug for discharging the spark plug, according to the ignition command signal, detects a value of the sparking voltage generated across the spark plug when the high voltage is generated, compares the detected value of the sparking voltage with a predetermined reference value, and determines whether or not a misfire has occurred in the engine, based upon results of the comparison. It is determined that the system is abnormal, when it is determined that no misfire has occurred while fuel supply to the engine is being interrupted.

Abstract: A sparking voltage detecting device for an internal combustion engine having an ignition system having at least one secondary side high-tension cord, is mounted on the secondary side high-tension cord, for detecting sparking voltage generated in the engine. A main body formed of an insulating material has at least one through hole formed therein. The high-tension cord is fitted through the through hole in a liquidtight manner. At least one conductive member is embedded in the main body at a location radially outward of the through hole and spaced from the high-tension cord by a predetermined distance.

Abstract: A sparking voltage detecting device for an internal combustion engine having an ignition system having at least one secondary side high-tension cord, is mounted on the secondary side high-tension cord, for detecting sparking voltage generated in the engine. A main body formed of an insulating material has at least one through hole formed therein. The high-tension cord is fitted through the through hole in a liquidtight manner. At least one conductive member is embedded in the main body at a location radially outward of the through hole and spaced from the high-tension cord by a predetermined distance. The main body has at least one incision formed therein, which extends from the outer surface of the main body to the through hole. The incision is forcibly expansible to an extent enough to allow the high-tension cord to be fitted into the conductive member is arranged at a side of the main body remote from the incision with respect to the through hole.

Abstract: A control system for an internal combustion engine determines ignition timing of the engine and generates an ignition command signal to generate high voltage for discharging a spark plug provided for each cylinder of the engine. The control system detects sparking voltage generated across the spark plug when the high voltage is generated. The control system measures a duration over which the sparking voltage across the spark plug exceeds a predetermined reference value, after generation of the ignition command signal. According to a first aspect of the invention, the control system detects combustion roughness based on the duration measured. According to a second aspect of the invention, the control means detects an air-fuel ratio of an air-fuel mixture supplied to the engine, based on the duration measured.

Abstract: A misfire-detecting system detects a misfire occurring in an internal combustion engine. A value of sparking voltage for discharging a spark plug of the engine is detected. The detected value of the sparking voltage is compared with a first predetermined value. A degree to which the detected value of the sparking voltage exceeds the first predetermined value is measured. The measured degree is compared with a second predetermined value. It is determined based upon results of the latter comparison whether or not a misfire occurred in the engine. According to a first aspect of the invention, the second predetermined reference value is set based upon detected values of operating parameters of the engine. According to a second aspect of the invention, the determination of occurrence of a misfire is inhibited when the engine is in a predetermined operating condition.

Abstract: A misfire-detecting system for an internal combustion engine detects a value of sparking voltage generated after generation of an ignition command signal, compares the detected value of sparking voltage with a predetermined voltage value, and determines whether or not a misfire has occurred in the engine, based upon results of the comparison. The determination as to occurrence of the misfire is effected, based upon results of the comparison between the detected value of the sparking voltage and the predetermined voltage value, obtained within a previously set limited comparison period.

Abstract: A misfire-detecting system detects a misfire occurring in an internal combustion engine. A value of sparking voltage after generation of an ignition command signal indicative of ignition timing is detected and compared with a predetermined voltage value, and it is determines based upon the results of the comparison whether or not a misfire has occurred in the engine. The determination as to occurrence of the misfire is based upon at least one of a time period over which the detected value of the sparking voltage exceeds the predetermined voltage value, and an area of a portion of detected values of the sparking voltage exceeding the predetermined voltage value.

Abstract: A system for aligning a mask and a semiconductor wafer comprises radiation source for producing a radiation beam, a dual focus linear Fresnel zone plate provided on the mask for focusing the radiation beam incident thereto on a surface of the semiconductor wafer which comprises a first part having a first focal length and a second part having a second focal length substantially smaller than the first focal length, a diffraction grating provided on the surface of the semiconductor wafer in correspondence to the dual focus linear Fresnel zone plate for diffracting the radiation beam focused thereon, a detector held with a predetermined relationship with respect to the radiation source and the mask for detecting the diffracted beam, a movable stage for supporting the semiconductor wafer, and a controller for moving the stage means responsive to an output signal of the detection means.

Abstract: A system for aligning a mask and a semiconductor wafer comprises radiation source for producing a radiation beam, a dual focus linear Fresnel zone plate provided on the mask for focusing the radiation beam incident thereto on a surface of the semiconductor wafer which comprises a first part having a first focal length and a second part having a second focal length substantially smaller than the first focal length, a diffraction grating provided on the surface of the semiconductor wafer in correspondence to the dual focus linear Fresnel zone plate for diffracting the radiation beam focused thereon, a detector held with a predetermined relationship with respect to the radiation source and the mask for detecting the diffracted beam, a movable stage for supporting the semiconductor wafer, and a controller for moving the stage means responsive to an output signal of the detection means.