Matsushita Electric Works, Ltd.

Kuniharu Tatetsuki

Kazuo Nakahi

Takeshi Nakano

Kazushige Morisue

Kouji Yamashita

Kazuhiro Honda

Tohru Hanahara

Masanori Kawai

Hiroshi Umeyama

Shigemi Sakurai

A polarization diversity radio communication system suitable for radio communication in indoor space is provided for transmitting from a transmitter a series of data sequentially from one of two or more transmission antennas of the transmitter, and for reproducing the data received at a receiver through a single reception antenna of the receiver when the series data are received from the transmitter. Thus, the transmitted data from any part of the indoor space can be received efficiently, and a high S/N ratio can be assured on the reception side.

Polarization diversity system suitable for radio communication in indoor

An antenna and its electronic circuit combination is presented to comprise a ground conductor plane 30, a radiating conductor plane 40 disposed in parallel spaced relation to the ground plane 30 and shorted at its one end to the ground plane 30. A ground plane 30 is preferably formed on a printed board 10 which is disposed in parallel relation to the radiating plane 40 to define therebetween an open air space. Mounted on the printed board 10 and received within the open air space are electronic components which form a receiving or transmitting electronic circuit 60 associated with the antenna structure and electrically coupled by means of a feed element 20 to a feed point 44 on the radiating plane 40. Consequently, a number of electronic components forming the electronic circuit for the antenna can well be incorporated within the antenna structure by better utilization of the open air space formed between the radiating and ground planes, giving a space saving compact arrangement to the antenna and its electronic combination suitable for installation in a limited space.

Antenna and its electronic circuit combination

A detection signal processing circuit for photoelectric smoke detectors reliably stable with respect to external noise is provided. Light receiving section of the detector for receiving light emitted intermittently from light emitting section and scattered by smoke particles comprises a light receiving element, a condenser charged depending on intermittent scattered light intensity received by the element and of a value over a predetermined level, and an output circuit providing an output to a following operation means only when charge amount of the condenser has reached a predetermined value. Optimumly, the predetermined value of the condenser charge is achieved when at least two or more of the intermittent scattered light are received continuously.

Photoelectric smoke detector

Growing community of inventors

Osaka, Japan

Kuniharu Tatetsuki