Patent ID: 6094143
Filing Date: 2000-07-25
Classification: G08B

Abstract:
A light obstruction type smoke sensor comprising:driving means for receiving a light generation control signal for a luminance control, and for outputting a driving current corresponding to said light generation control signal;light generating means for outputting light of luminance corresponding to said driving current;light receiving means for receiving light which is output from said light generating means and passes through a space of a monitoring area, and for outputting a level of said received light;light generation controlling means for comparing said received light level with a predetermined reference level, for, when a difference of the levels is in an allowable range, increasing or decreasing said light generation control signal to reduce the level difference, and for outputting said light generation control signal; andsmoke sensing means for detecting smoke in an optical path between said light generating means and said light receiving means based on said received light level, and for outputting an alarm signal when said received light level is equal to or lower than a predetermined alarm level .