Denso Corporation

Mitsubishi Heavy Industries Engine & Turbocharger, Ltd.

Nobuyuki Taguchi

Takamoto Watanabe

Shigenori Yamauchi

Akimitsu Sugiura

Kenji Kanehara

Akihiro Yuuki

Ryu Suzuki

Tomohiro Noguchi

Naoki Kido

Minoru Ichihara

In a laser ignition device which is mounted in an internal combustion engine and at least includes a laser spark plug equipped with an optical window which protects an optical device from high temperature and high pressure generated in a combustion chamber and a prechamber cap equipped with a cylindrical prechamber, a prechamber throat portion that is a bottomed cylinder with a sectional area smaller than that of the prechamber, and a plurality of prechamber spray holes which communicate with a combustion chamber on a side of a closed end of the prechamber throat portion, the prechamber cap is arranged between the optical window and the combustion chamber. A converging point FP is located inside the prechamber to ignite an air-fuel mixture delivered into the prechamber, thereby jetting combustion flames from the prechamber into the combustion chamber to fire the internal combustion engine. The center axis AXof the prechamber is oriented horizontally eccentrically from the center axis AXof the prechamber throat portion.

Laser ignition device

A first encoding part encodes a reference timing determined by a reference clock by using a delay line. A second encoding part encodes a measurement start timing and a measurement end timing of a measurement period determined by a measurement signal to be measured by also using the delay line. A count part counts the reference clocks included in the measurement period. A fraction calculation part calculates a start fraction number indicating a time difference from the measurement start timing and an immediately-following reference timing and an end fraction number indicating a time difference from the measurement end timing to an immediately-following reference timing, based on the encoding result. The fraction calculation part then calculates a fraction data indicating a difference between the measurement period and a product of the period of the reference timing and the count value of the count part.

Time measuring circuit

A digital control oscillator circuit includes: a ring oscillator having delay elements delaying a pulse signal; a counter circuit counting the circulation number of the pulse signal; a rough period generation unit acquiring a period setting value as a magnification ratio for a reference clock, and counting the reference clock using an integer part of the ratio to generate a rough period timing; a fraction conversion unit converting a decimal point part of the ratio into the number of the elements passed by the pulse signal to generate a fraction; and an output processing unit selecting a timing when outputs of the ring oscillator and the counter circuit become values corresponding to the fraction as an output timing when a time corresponding to the fraction has passed after the rough period timing, and generating an output signal oscillating at a period represented by the period setting value according to the output timing.

Digital control oscillator circuit

In a gyro sensor, a TDC detects a magnitude of vibration of a vibrator. A drive circuit (excluding the TDC) determines a duty ratio of a PWM drive signal in accordance with the magnitude of vibration so that the magnitude of vibration becomes a predetermined magnitude and outputs the PWM drive signal having the determined duty ratio. The drive circuit (excluding the TDC) includes a control circuit and a DCO. The control circuit measures time corresponding to the control value by using a gate delay time, generates the PWM drive signal having a pulse width corresponding to the control value and outputs the PWM drive signal.

Vibration generation apparatus

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Kariya, Japan

Nobuyuki Taguchi