There are provided a first ignition timing table for high-octane fuel and a second ignition timing table for low-octane fuel. When the second table is switched over to the first table, there is at first the difference in between basic ignition timings according to the first and second tables, and then the difference is reduced with time at a constant rate. An actual ignition timing during the switchover of an ignition timing table is determined by subtracting the reducing difference from the basic ignition timing according to the first table. The actual ignition timing when knocking is detected is compared with a predetermined threshold. If the former exceeds the latter, the second table is switched over to the first table, and otherwise the second table is maintained, whereby the actual ignition timing can be changed smoothly even during the switchover of an ignition timing table.

Ignition timing control apparatus for an internal combustion engine

A knock control system for an internal combustion engine has a knock discrimination level. If an output signal from a knock sensor is higher than the knock discrimination level, then the knock control system determines that the engine is subjected to knock and retards the ignition timing. If the knock sensor output signal is lower than the knock discrimination level, i.e., if no knock or detonation is detected over a prescribed period of time, then the ignition timing is advanced. At least two corrective levels are established for comparison with a knock discrimination level, and occurrences in which the maximum value of the output signal from the knock sensor exceeds the corrective levels. The knock discrimination level is automatically corrected dependent on the counts of such occurrences.

Knock control system for internal combustion engine

A three beam laser optical system comprising a writing beam and two reading beams all incident on the same track of a rotating disk optical recording medium. One of the reading beams is incident on the track ahead of the writing beam so as to serve as a read-before-write beam, while the other reading beam is incident on the track behind the recording beam so as to serve as a read-after-write beam. The read-before-write beam is used during the recording of data to provide an advance indication as to whether there is previously recorded data ahead of the writing beam, in which case the recording operation is interrupted to prevent an overwrite error. The read-after-write beam is used during recording to check the accuracy of the recording operation.

Three beam optical memory system

In an optimum control for an internal combustion engine, a engine is operated by dithering the value of a selected one of engine operating control variables from a value of the selected control variable which is obtained by calculation in accordance with detected values of operating parameters of the engine, and a direction of improving either one of a fuel consumption rate and an output of the engine is decided on the basis of a detected change of an engine operating condition, thereby correcting the value of the selected control variable. In the optimum control, the time period for detecting a change of an engine speed within the time period for effecting the dithering is increased or decreased as the engine speed increases or decreases, respectively. Thus, this optimum control makes it possible to perform accurate control with a reduced dither quantity and a shorter dither period than previously.

Method and apparatus for optimum control of internal combustion engines

An optical data storage system employing a data-modulated writing laser beam and a non-erasing reading laser beam of predetermined wavelength along with an improved optical medium comprised of multiple layers whose optical characteristics and thicknesses are chosen in conjunction with the writing and reading laser beams to provide an anti-reflection condition for unrecorded portions of the medium and a relatively high reflectivity for recorded portions of the optical medium. A preferred optical medium includes a highly reflective aluminum layer, a fluorinated hydrocarbon polymer spacer layer overlaying the reflective layer, and a gold absorber layer overlaying the spacer layer.

Optical storage system employing a novel multi-layer optical medium

A knocking suppression apparatus for an internal combustion engine has a noise removal circuit which is disposed between an acceleration sensor, which senses engine knocking, and a phase shifter, which controls the ignition timing of the engine. The noise removal circuit includes a switch which can be opened and closed to prevent signals from being input to the phase shifter, and a window comparator. When the window comparator determines that the output of the acceleration sensor contains high-level noise signals, the noise removal circuit opens the switch for a prescribed period to prevent the high-level noise signals from being input to the phase shifter and influencing the ignition timing.

Knocking suppression apparatus for an internal combustion engine

A control apparatus for an internal combustion engine in which the condition of the operating parameters of the engine is changed over according to the detected result of the occurrence of knocks only when the engine lies in a predetermined operating region. The operating parameters include an ignition timing, a supercharging pressure, a compression ratio, and an air/fuel ratio. The knocks of the engine are integrated and compared with a threshold level to determine which of premium or regular gasoline is being used. In this determination, if the operating region lies in said predetermined operating region, the condition of the operating parameters is changed over. The predetermined operating region is defined by a load information and a speed information of the engine.

Engine operating parameter control apparatus

A recording optical system forms a recording spot to record a pitted signal on a record surface. A first reproducing optical system forms a reproducing spot fixed with respect to the recording spot on the record surface for monitoring purposes, and a second reproducing optical system with the greater part of the optical components thereof common to the first reproducing optical system and also including a rotatable reflecting mirror for forming a tracking spot on the record surface. The tracking spot is movable on the recorded signal by the rotation of the mirror in response to the light reflected from the record surface for causing the tracking spot to accurately track the pitted signal on the record surface.

Optical signal recording and reproducing system

An electro optical modulation system utilizes electro optical effect of a crystal. The electro optical modulation system comprises a voltage comparator for comparing a modulated light intensity signal with a reference voltage; and a bias controlling device which feeds a differential signal between mean value signal of the output of the voltage comparator and mean value signal of the inverted output of the voltage comparator, to an optical modulator as a bias voltage.

Electro optical modulation system

An ignition timing correcting system generates a reference timing signal at a reference angular position of a rotating internal combustion engine and a ignition timing signal leading it by a constant phase. The latter signal is controllably retarded in phase to form a retarded ignition timing signal. The phase comparison of the two signals produces an advance or a retardation correcting signal formed of a pulse train having a pulse width corresponding to the phase difference between them. During the idling of the engine, the correcting signal drives a reversible motor forwardly or reversely to move a movable top on a potentiometer to adjust a control signal provided from the latter. When the pulse width becomes sufficiently narrow, the correcting signal is disabled to drive the motor resulting in the required control signal. That control signal corrects the retardation of the retarded ignition timing signal to a regular ignition timing.

Satoshi Komurasaki

Papers

Knocking suppression apparatus for an internal combustion engine

Engine operating parameter control apparatus

Optical signal recording and reproducing system

Electro optical modulation system

Ignition timing correcting system for internal combustion engine