Abstract: A smoke detector includes: a casing; a first light emitting unit; a second light emitting unit; and a light receiving unit. A second scattering angle that is an angle between the reception axis of the light receiving unit and a second extension extending from an intersection of the second emission axis and the reception axis in a direction away from the second light emitting unit is larger than a first scattering angle that is an angle between the reception axis of the light receiving unit and a first extension extending from an intersection of the first emission axis and the reception axis in a direction away from the first light emitting unit.

Abstract: A light-receiving element and a first light-emitting element are disposed in a position in which the light-receiving element receives forward-scattered light produced when smoke in the smoke detection part is irradiated with first irradiation light emitted from the first light-emitting element. A secondary reflecting plate is provided on a side of the first light-emitting element inside the peripheral wall. The secondary reflecting plate is configured to form secondary reflected light when the smoke detection part without smoke is irradiated with the first irradiation light. The secondary reflecting plate receives primary reflected light resulting from reflection of the first irradiation light from the peripheral wall and reflects the primary reflected light, and then allows the formed secondary reflected light to enter the light-receiving element.

Abstract: Problems: There is a technology using the reflected light which is emitted from the light-emitting element and reflects without being absorbed in the inside of the optical bench, in order to detect whether the light-emitting element and the light-receiving element normally function. In this case, they do not normally function when there is either too little or too much reflected light in the inside of the optical bench. It is therefore an object of the present invention to achieve a suitable amount of reflected light inside the optical bench. Means for solving the problems: A light-receiving element 93 and a first light-emitting element 91 are disposed in a position in which the light-receiving element 93 receives forward-scattered light produced when smoke in the smoke detection part 10 is irradiated with first irradiation light emitted from the first light-emitting element 91. A secondary reflecting plate 716 is provided on a side of the first light-emitting element 91 inside the peripheral wall.

Abstract: A smoke detector includes: a casing; a first light emitting unit; a second light emitting unit; and a light receiving unit. A second scattering angle that is an angle between the reception axis of the light receiving unit and a second extension extending from an intersection of the second emission axis and the reception axis in a direction away from the second light emitting unit is larger than a first scattering angle that is an angle between the reception axis of the light receiving unit and a first extension extending from an intersection of the first emission axis and the reception axis in a direction away from the first light emitting unit.

Abstract: A sprinkler head employing balls for a heat-sensitive disassembling unit is provided, in which the time period from when a fusible alloy starts to melt until when the sprinkler head is activated is shortened. A sprinkler head includes a frame having a stepped portion projecting inward. The stepped portion has an upper inclined surface provided at the inner-peripheral upper edge thereof and with which balls come into contact, and a guide part provided at the inner-peripheral lower edge thereof and that allows any of the balls that is displaced from the upper inclined surface to move downward from the stepped portion. When a fusible alloy melts, the ball displaced from the upper inclined surface moves along the guide part and is quickly released to the outside of the frame. Hence, the time period from when the fusible alloy starts to melt until when the sprinkler head is activated is shortened.

Abstract: A fire monitoring system includes a smoke detector, a first correction unit obtaining a first corrected value by multiplying a difference value between a reference value and a detection value by a first correction coefficient, a first conversion unit converting the first corrected value into a first smoke density, and a fire determination unit determining occurrence of a fire event based on the first smoke density. The first correction coefficient is set on an increase side corresponding to an increase in a rate of change of the reference value to an initial reference value, and an upper limit value is set for the first correction coefficient.

Abstract: A fire monitoring system includes a smoke detector, a first correction unit obtaining a first corrected value by multiplying a difference value between a reference value and a detection value by a first correction coefficient, a first conversion unit converting the first corrected value into a first smoke density, and a fire determination unit determining occurrence of a fire event based on the first smoke density. The first correction coefficient is set on an increase side corresponding to an increase in a rate of change of the reference value to an initial reference value, and an upper limit value is set for the first correction coefficient.

Abstract: A sprinkler head 1 includes a head body 10 having a water discharging cylinder 16 in the interior thereof, a frame 20 connected to the head body 10, a valve body 30 provided in the interior of the frame 20 and closing a water discharging port 12 of the water discharging cylinder 16, a thermosensitive portion 51 configured to support the valve body 30, and a disk spring 64 provided between the valve body 30 and the thermosensitive portion 51. A set screw 65 to be coupled to the thermosensitive portion 51 is provided under the valve body 30, and the set screw 65 is inserted into a through hole 64a at the center of the disk spring 64. The set screw 65 includes a head portion and a leg portion, and the head portion is formed to be higher than the height of the disk spring 64.

Abstract: Provided is a fire alarm system including: a transmitter/receiver unit (4) for supplying a pulse voltage to power/signal lines (SG); a current value setting unit (5) for setting, as a current limiting value, an upper limit of a current output to the power/signal lines (SG) from the transmitter/receiver unit (4) when the pulse voltage is output; and a current control unit (6) for controlling the transmitter/receiver unit (4) to output a current having a value equal to or smaller than the current limiting value set by the current value setting unit (5). Accordingly, it is possible to prevent a malfunction from occurring in communications irrespective of a scale of the fire alarm system.

Abstract: An aperture member (15) is configured to be mounted to a receiving portion (22) provided to a main body (2), and includes a lower surface portion (15a) formed into an arc shape. The receiving portion (22) of the main body (2) includes a bottom surface portion (22a) formed into a shape corresponding to the arc shape of the lower surface portion (15a) of the aperture member (15) so as to be brought into contact with the lower surface portion (15a) of the aperture member (15). The aperture member (15) includes a light passage opening (15e) formed so that a center position (15ea) thereof substantially matches with a position of a center of curvature of the arc shape of the lower surface portion (15a).

Abstract: A fire control panel in which an address map window (30), in which terminal device control switches (31) each indicating an address number (AD) of a terminal device are arranged in a matrix shape, is displayed on a display/operation unit (2). In addition, each of the terminal device control switches (31) corresponding to a status stored in a terminal database (DB) is displayed in a display mode that differs depending on each status. Accordingly, it is possible to grasp status information on a large number of terminal devices at a glance through one screen.

Abstract: A smoke detector (1) includes: a light emitting section (6); a light receiving section (7); a smoke detecting section (12), the smoke detector (1) being configured to detect smoke or the like in a manner that the light receiving section (7) receives, via a light transmissive member (11), scattered light generated when light emitted from the light emitting section (6) is scattered in the smoke detecting section (12) due to particles of the smoke or the like; and a test light source (22) provided for detecting light receiving sensitivity of the light receiving section. The smoke detector (1) is further configured to detect a reduction in the light receiving sensitivity of the light receiving section (7) through detection of an increase in received light intensity of test light, which is emitted from the test light source (22) and is received by the light receiving section (7).

Abstract: Provided is a short-circuit isolator capable of earlier detection of recovery from short circuit of a disconnected line and reconnecting the line.

Abstract: An aperture member (15) is configured to be mounted to a receiving portion (22) provided to a main body (2), and includes a lower surface portion (15a) formed into an arc shape. The receiving portion (22) of the main body (2) includes a bottom surface portion (22a) formed into a shape corresponding to the arc shape of the lower surface portion (15a) of the aperture member (15) so as to be brought into contact with the lower surface portion (15a) of the aperture member (15). The aperture member (15) includes a light passage opening (15e) formed so that a center position (15ea) thereof substantially matches with a position of a center of curvature of the arc shape of the lower surface portion (15a).

Abstract: A fire alarm system transmitter includes: a printed circuit board with a substantially rectangular shape, on which a terminal block including a plurality of terminals aligned along one side of the printed circuit board is disposed; a casing with a substantially rectangular parallelepiped shape, in which the printed circuit board is mounted; and an electric-wire insertion portion provided on a side wall of the casing facing the one side, and extended from the side wall by a predetermined distance toward an outside of the casing. The side wall allows a plurality of electric wires connected to the plurality of terminals to be inserted through the side wall.

Abstract: Provided is a photoelectric smoke sensor capable of correcting a sensitivity according to a state of contamination. The photoelectric smoke sensor includes: a storage section (6) for storing a zero detection value VN and an initial zero detection value; a moving average value calculating section (51) for calculating a moving average value of detection AD values output from a detection portion (1, 2, 3); a zero detection value updating section (52) for calculating a new zero detection value VN when a sensitivity of the detection portion is decreased as compared with that in an initial state, and in addition, when a rate of change in the moving average value with respect to the zero detection value VN exceeds a predetermined value; a detection AD value correcting section (53) for correcting the detection value; and a smoke-density computing section (54) for converting the corrected detection value into smoke-density data.

Abstract: Provided is an alarm device capable of performing transmission and reception reliably while suppressing an amount of current consumption. An alarm device (100) includes: a fire detection circuit (7); a control circuit (1); and a transmitting/receiving circuit (5). The transmitting/receiving circuit (5) transmits the status signal to the another alarm device (100) with a transmission pattern formed by combining transmission periods and transmission suspension periods a predetermined number of times, and receives the status signal transmitted by the another alarm device (100) in an intermittent reception cycle. A time length of each of the transmission periods and the transmission suspension periods is set so that the another alarm device (100) that has failed to receive the status signal transmitted in a first intermittent reception cycle can receive the status signal in a second intermittent reception cycle and subsequent intermittent reception cycles.

Abstract: Provided is a fire detector in which an element substrate can be easily removed from and mounted into an optical case. The fire detector includes: an optical case (21); an element substrate (31), on which a light-receiving element (12) is mounted, the element substrate (31) being provided in the optical case (21); a signal line (35) passing through an introduction portion of a peripheral wall (21a) of the optical case (21), the signal line (35) being connected to the element substrate (31); and an optical cover (30) for closing an opening of the optical case (21), in which the signal line (35) is inserted into a slit (37) which is open on an upper end surface (21f) of the introduction portion of the peripheral wall (21a).

Abstract: An alarm system and an alarm device that are capable of enhancing a fail-safe function. A fire alarm device (A) operating as a master unit transmits a switching request signal to fire alarm devices operating as slave units at a predetermined timing. The switching request signal contains at least an own address and an address of a fire alarm device (B) that is to operate as the master unit next (S20). Upon reception of the switching request signal, among the fire alarm devices operating as the slave units, the fire alarm device (B) that is to operate as the master unit next judges whether or not switching is possible based on switching availability judgment information for judging whether or not switching to the master unit is possible (S30), and, when it is judged that switching is possible, starts operating as the master unit (S31).