Abstract: A laser type ignition device for an internal combustion engine includes a laser oscillator mounted in the internal combustion engine so as to focus its laser beam on an air-fuel mixture supplied into the combustion chamber, a pressure sensor for detecting pressure in the combustion chamber, a power source for the laser oscillator and a control unit for controlling the power source to supply the laser oscillator with the current whose amount changes according to the pressure in the combustion chamber. The power of the laser beam increases as the pressure in the combustion chamber decreases to completely ignite the air-fuel mixture.

Abstract: A laser type ignition device for an internal combustion engine includes a laser oscillator mounted in the internal combustion engine so as to focus its laser beam on an air-fuel mixture supplied into the combustion chamber, a pressure sensor for detecting pressure in the combustion chamber, a power source for the laser oscillator and a control unit for controlling the power source to supply the laser oscillator with the current whose amount changes according to the pressure in the combustion chamber. The power of the laser beam increases as the pressure in the combustion chamber decreases to completely ignite the air-fuel mixture.

Abstract: A holographic particle-measuring apparatus is provided that can improve the precision of measurement by photographing only particles through the elimination of noise. In an off-axis holographic optical image pick-up device (100), object beams (L1) that is a flux of parallel beams are irradiated onto particles (114) as a subject. At the same time, reference beams (L2) are incident, with an inclination, onto the object beams (L1) after being irradiated onto the particles (114). An interference fringe generated as a result of the interference between the object beams (L1) and the reference beams (L2) is recorded onto a recording material Noise elimination relay lenses (116a and 116b) are installed between the particles (114) and the recording material (115). Further, a noise elimination pinhole plate (117) having a pinhole (118) is installed between the lenses (116a and 116b) constituting the relay lens.