Matsushita Electric Works, Ltd.

Yoshihiko Okuda

Tsunehiko Araki

Takeshi Nakano

Atsuyuki Hirono

Yoshiaki Kambe

Takayasu Ito

Akira Nagaoka

Motoo Ikari

Haruhiko Momose

Yoshiaki Kanbe

Yuki Yorifuji

Kunisige Kurata

Shigeru Matsumoto

Hitoshi Miyashita

An optical sensor discriminating the presence of an object or detecting distance to an object which includes a light projecting element for projecting light to a detection area, a light receiving element for receiving light reflected from an object present in the detection area and an anamorphic light receiving lens for expanding a condensed light spot received on the light receiving element in a direction perpendicular to a direction of movement of the light spot on the light receiving element. The light receiving element outputs a detection signal which discriminates the presence of the object in the detection area. The light receiving element can be rectangular in shape and comprise two or more triangular shaped photodiodes which output detection signals that can be processed to determine a distance between the object and the light receiving element. A movable prism can also be provided to compensate for movement of the object other than towards or away from the light receiving element to avoid erroneous distance measurement which might otherwise occur.

Optical sensor for detecting distance to an object including anamorphic

An optical sensor comprises a sensor circuit having parts which are optically interconnected with each other through an optical interconnection board interposed therebetween. The interconnection between the sensor circuit parts is thereby simplified remarkably, so that the mass-producibility of the sensor can be increased to lower its manufacturing costs.

Optical sensor with optical interconnection board

There is provided a photoelectric switch in which a beam reflected by an object to be detected is received in a trigonometric manner so that any failure in the distance measurement of the object can be prevented with employment of ordinary amplification circuit for received-light signals without enlarging the figure of the dynamic range of the circuit. In the switch, a circuit for comparing the ratio of the received-light signals to a predetermined operational level includes means for setting the nearest limit point for a set range of a detecting area to be farther than an intersection of the projected light beam with a line connecting centers of light-receiving lens and received-light detecting element so that the detection of the object can be made even when the dynamic range of the amplification circuit is saturated, whereby the presence of the object in the detecting area can be always discriminated even upon the dynamic range saturation of the amplification circuit.

Photoelectric switch with limit setting means to prevent disablement

An ionization type smoke sensing device includes a printed board. An inner electrode made of heat-resistant metal is attached to the printed board and a radioactive source is fixed to the inner electrode. An outer electrode in the form of a bottomed cylinder made of heat-resistant metal and adapted to cover the inner electrode extends through the printed board and is integrally joined to a protective lid member made of heat-resistant metal at the back of the printed board. Therefore, the outer electrode and the lid member cooperate with each other to define an ionization chamber. The outer electrode is formed with smoke inlet ports for introducing smoke into the ionization chamber. The electric circuit serves to give pulse signals of a relatively high voltage to the outer electrode and to detect the presence of smoke on the basis of the amount of a current flowing through the inner electrode.

Ionization type smoke sensing device

A light scattering type smoke detector effectively sensitive both to white and black smokes is provided. A wave length .lambda. of an incident light from a light source and a scattered light receiving angle .theta. defined by the direction of the incident light and the direction connecting between a smoke particle and a light receiving element are so determined as to satisfy .lambda. .ltoreq. 950 m.mu. when .theta. .ltoreq. 45.degree., .theta. .ltoreq. - 0.18 .lambda. + 216 when 45.degree. .ltoreq. 135.degree. and .theta. .ltoreq. 135.degree. when .lambda. .ltoreq. 450 m.mu..

Light scattering type smoke detector

A smoke sensing device of the type having a single ionization chamber wherein stability and reliability are increased by driving the ionization chamber from a square wave oscillator, and utilizing an A.C. amplifier responsive to the ionization current within the chamber. The A.C. amplifier serves to amplify the current through the ionization chamber and couple the amplified current to a rectifier and detector adapted to respond to decreases in current, such as caused by smoke particles within the ionization chamber, to activate an alarm device.

A light scattering type smoke detector minimized in size and protected from erroneous operation and from internal accumulation of water drops is provided. The optical comprises light emitting and receiving elements and light shielding means which are compactly mounted on a base plate at different heights so as normally to prevent light from the emitting element to reach the receiving element. A power source part for the light emitting element disposed at one side of the optical system and an amplifying part for the light receiving element disposed at the other side of the system are housed in an upper lid having drain means, and a lower lid having many small holes for smoke lead-in is attached to the upper lid.

Growing community of inventors

Ikoma, Japan

Yoshihiko Okuda