Abstract: An improved fire detector unit has a plastic base defining a smoke chamber for detection of a smoke density in terms of light scattering due to the smoke particles in the smoke chamber. The base carries a circuit board mounting a light emitting element, a light receiving element, and other components forming a fire detecting circuit responsible for generating a fire warning signal based upon the detected smoke density. A metal-made electromagnetic shield is molded into the base to protect the light receiving element from electromagnetic radiation noises. The electromagnetic shield includes a ground terminal for connection with a ground line of the circuit board. In addition, terminal pins are molded into the base for electrical and physical connection of the circuit board to the base.

Abstract: A particle sensor has a gain control and an offset voltage adjustment so as to provide a consistent sensor output indicative of the particle density in match with a predetermined relationship between the sensor output and the particle density, while compensating for background noises. The gain control and the offset voltage adjustment are realized respectively by digitally controllable variable resistor networks each having a plurality of switches. A memory module is included in the sensor to store instruction data for control of the switches and therefore responsible for the gain control and the offset voltage adjustment. In particular, the particle sensor includes a memory interface which enables the selective use of two types of memory means, one is an intelligent memory module composed of EEPROM and a microcomputer, and the other is a normal memory module consisting of EEPROM.

Abstract: A method of fabricating various models of fire detectors only from a limited number of common parts or unit in accordance with user's specific needs but at a reduced cost. The method utilizes a smoke sensor unit (1), a thermal sensor unit (2), a signal processing unit (3), a signal transmission unit (4), and a power unit (5), and then combines at least one of the smoke sensor unit and the thermal sensor unit with the power unit and optionally with at least one of the signal processing unit and the signal transmission unit.

Abstract: A method of fabricating various models of fire detectors only from a limited number of common parts or unit in accordance with user's specific needs but at a reduced cost. The method utilizes a smoke sensor until (1), a thermal sensor unit (2), a signal processing unit (3), a signal transmission unit (4), and a power unit (5), and then combines at least one of the smoke sensor unit and the thermal sensor unit with the power unit and optionally with at least one of the signal processing unit and the signal tansmission unit.

Abstract: An improved fire detector unit has a plastic base defining a smoke chamber for detection of a smoke density in terms of light scattering due to the smoke particles in the smoke chamber. The base carries a circuit board mounting a light emitting element, a light receiving element, and other components forming a fire detecting circuit responsible for generating a fire warning signal based upon the detected smoke density. A metal-made electromagnetic shield is molded into the base to protect the light receiving element from electromagnetic radiation noises. The electromagnetic shield includes a ground terminal for connection with a ground line of the circuit board. In addition, terminal pins are molded into the base for electrical and physical connection of the circuit board to the base.

Abstract: A particle sensor has a gain control and an offset voltage adjustment so as to provide a consistent sensor output indicative of the particle density in match with a predetermined relationship between the sensor output and the particle density, while compensating for background noises. The gain control and the offset voltage adjustment are realized respectively by digitally controllable variable resistor networks each having a plurality of switches. A memory module is included in the sensor to store instruction data for control of the switches and therefore responsible for the gain control and the offset voltage adjustment. In particular, the particle sensor includes a memory interface which enables the selective use of two types of memory means, one is an intelligent memory module composed of EEPROM and a microcomputer, and the other is a normal memory module consisting of EEPROM.

Abstract: A multi-lens system provides a plurality of sensitive areas of even size over a wide panoramic field of view and reduces an exposure height of the system above an installation plane, yet assuring successful motion detection. The system has a dome-shaped shell with a plurality of convex lenses for collecting infrared radiation from the panoramic field of view to an optical detector positioned in a focal region. The lenses are distributed over a wide solid angular range to give the discrete sensitive areas. The focal region is offset towards a vertex of the shell from a point where optical axes of the outermost lenses at a maximum solid angle about the center axis intersect with each other. Thus, the outer lens at a greater angular disposition has a greater distance to the detector so that it could define its own sensitive area closer in size to the adjacent sensitive area defined by the adjacent lens at a less angular disposition, enabling to equalizing the discrete sensitive areas.

Abstract: A personal body detecting device makes it possible to determine the presence and absence of a personal body in a detecting zone by sensing infrared rays in the zone with a plurality of infrared ray detecting elements, detecting at a discriminating means a peak level and output time in connection with respective outputs of the infrared ray detecting elements, and comparing them with each other. The personal body having reached the detecting zone in any direction thereto can be reliably detected, and a highly reliable detecting operation can be realized.

Abstract: A person-number detecting system which comprises a detector for detecting infrared rays emitted from persons' bodies to generate an output signal while a scanning optical means circularly scans a visual field of the infrared ray detector, a means for amplifying the output signal of the detector, a means for converting it to a signal necessary for detection of the number of persons located within the field, a means for discriminating the number of persons on the basis of the converted signal, and a means for outputting person number information. The system can be made simple and inexpensive, while realizing a highly precise detection of the number of persons in a wide detection zone.