Abstract: A slice decoder control circuit sequentially supplies the parameter of the picture layer and the write pointer of a first slice to a first slice decoder, the parameter of the picture layer and the write pointer of a second slice to a second slice decoder, and the parameter of the picture layer and the write pointer of a third slice to a third slice decoder, and causes the slice decoders to decode the respective parameters and write pointers. On the basis of the input of signals indicating the completion of decoding processing inputted from the slice decoders, the slice decoder control circuit supplies the write pointer of a fourth slice to the second decoder and causes the second slice decoder to decode the write pointer at timing A, and supplies the write pointer of a fifth slice to the third decoder and causes the third slice decoder to decode the write pointer at timing B. Subsequently, the similar processing is repeated until the last slice is decoded.

Abstract: A slice decoder control circuit (46), having received the input of a parameter of a picture layer, sequentially supplies the parameter of the picture layer and the write pointer of a slice 1 to a slice decoder (47), the parameter of the picture layer and the write pointer of a slice 2 to a slice decoder (48), and the parameter of the picture layer and the write pointer of a slice 3 to a slice decoder (49), and causes the slice decoders to decode the respective parameters and write pointers. On the basis of the input of signals indicating the completion of decoding processing inputted from the slice decoders (47) to (49), the slice decoder control circuit (46) supplies the write pointer of a slice 4 to the slice decoder (48) and causes the slice decoder (48) to decode the write pointer at timing A, and supplies the write pointer of a slice 5 to the slice decoder (49) and causes the slice decoder (49) to decode the write pointer at timing B.

Abstract: An inexpensive smoke detector having excellent general versatility and reliability allows for an increase in a range of selecting light emitting devices used for such smoke detectors and allows for reductions in the number of processes and adjustment equipment, thereby reducing costs and avoiding human adjustment errors. The smoke detector includes an A/D conversion circuit for measuring an output from a photo transistor which receives a light output of at least a light emitting diode used for smoke detection. A MPU generates a signal for driving the light emitting diode, based on a value measured by the A/D conversion circuit. The smoke detector also includes an EEPROM. A D/A conversion circuit adjusts a light emission quantity of the light emitting diode based on a value read from the EEPROM. The smoke detector further includes a voltage/current conversion circuit.

Abstract: A fire detecting apparatus is designed to have improved reliability by reducing the possibility that the apparatus is influenced by an environmental change, external noise or the like which would otherwise cause erroneous fire information to be sent to a receiving unit to generate a false alarm.

Abstract: A photoelectric type fire detector is capable of accurately adjusting sensitivity using a scattering and translucent plate and exhibits excellent reliability.

Abstract: A fire detector is capable of self-detecting its own malfunction and is also capable of quickly announcing a failure of high-level emergency in the fire detector. A plurality of determining values are established for the output level of a physical quantity detector for detecting the physical quantity of a fire phenomenon such as smoke, and a different time is set for each of the determining values. A shorter time is set for greater deviation from the normal value of the output level. It is determined that the physical quantity detector is faulty if it is detected that the output level of the physical quantity detector continuously exceeds any of the established determining values for not less than the time which has been set for that particular determining value.

Abstract: A fire alarm system exhibiting satisfactory reliability and capable of easily and assuredly setting address and various discrimination values to terminal units. The fire alarm system has a setting unit including a first command unit, a first discrimination unit for discriminating whether or not a transmitted set value transmitted by the first command unit and a set value received from a detector coincide with each other, a second command unit for transmitting the set value to the detector when the received set value and the transmitted set value coincide with each other, and a second discrimination unit for discriminating whether or not the received set value and the set value transmitted from the first or the second command unit coincide with each other.

Abstract: A smoke type fire detector accurately detects a smoke density even when an internal temperature thereof changes. An internal temperature detecting unit detects an ambient temperature at a light emitting element and a light receiving element. A correction coefficient having a value associated with the ambient temperature detected by the temperature detecting unit is used to correct an output level of the light receiving element.

Abstract: A sensitivity measuring apparatus for use with a fire detector comprising includes sensitivity measuring portions, a calibrating signal generator, and a calibrator. The sensitivity measuring apparatus also includes a type identifier for the type of the fire detector on the basis of the output signal from the fire detector. The apparatus thus needs no manpower during its adjustment procedure to regulate the tolerance of the internal circuit. The apparatus also eliminates a source of erroneous measurements in the course of sensitivity measurement of the fire detector.

Abstract: A signal transmission circuit provided with a control panel or a terminal device of a fire/security protection system is arranged so as to transmit a signal for the control panel or terminal device to a signal line. The signal transmission circuit includes: a signal transmission which is enabled when transmitting a signal under the control of a signal processing portion; a signal detector for detecting the signal transmitted from the signal transmitter to the signal line; a timer which is set when the signal is transmitted and is reset by the detection output from the signal detector, and a signal transmission controller for turning off the signal transmitter when the time count output of the timer exists during a predetermined time interval.

Abstract: In a fire alarm system wherein a receiver polls terminal devices having CPU's, such as fire detectors, fire sensors and repeaters, and the receiver reads monitoring information called from the terminal device or transmits control information thereto; a fire alarm system constructed so that each of said terminal devices having a CPU brings said CPU included therein into a standby status when a polling address of said receiver and an intrinsic address of said terminal device are different.

Abstract: A photoelectric smoke detector is provided with first and second radiation emitters and first and second radiation receivers. The first emitter emits pulsed radiation at a predetermined frequency. The second emitter emits pulsed radiation at twice this frequency. The first receiver receives the radiation of the second emitter directly and that of the first emitter by scattering only. When the first receiver receives alternate detection pulses reinforced by scattered radiation, an alarm is generated. The second receiver receives radiation directly from the first emitter and modulates the radiation output level of the second emitter proportionately. When the first receiver receives testing pulses between the alternating detection pulses, their level is discriminated to determine the functional state of the detecting elements and a corresponding function signal is generated.