Abstract: An ignition timing controller for an automobile in which at least two reference ignition point signals are established for each cylinder, and the ignition timing is set according to the reference ignition point signal that is closer to the target ignition timing.

Abstract: Cross-sectionally fan-shaped metal segments 10a, 10b and 10c, shown in FIG. 1, are longitudinally assembled along an optical fibre to form a pressure-resistant sheath 10 for protecting an optical fibre unit for use in a transmission medium of a submarine optical fibre cable. The inner surfaces 11a, 11b, and 11c, shown in FIG. 1, of the metal segments 10a, 10b and 10c as well as all the contact faces 12a, 12b, and 12c also shown in FIG. 1 are so roughened that the adhesion force associated with the optical fibre unit 1 and the pressure-resistant sheath 10 and the metal segments themselves 10a, 10b and 10c can be strengthened enough to protect the optical fibre unit. Water penetration which may occur in case of cable damages can also be prevented.