Patent ID: 8648307
Filing Date: 2014-02-11
Classification: G01J,G01V,G08B

Abstract:
1. An infrared ray detector comprising a prism element for passing infrared ray from a first side of the prism element to a second side of the prism element opposite to the first side; a housing formed with an opening for introducing the infrared ray passed through said prism element; a condenser lens configured to condense the infrared ray introduced into said housing through said opening; an infrared ray receiver configured to receive the infrared ray condensed by said condenser lens, and to output electric signal according to the received infrared ray; wherein said prism element includes a plurality of V-shaped grooves and exit faces each formed between said V-shaped grooves, V-shaped groove including refractive face, said refractive faces being shaped to convert the infrared ray incident on the refractive face at a predetermined inclined angle with respect to an optical axis of said prism element to the infrared ray proceeding along the optical axis, each of said exit faces being shaped to take in the infrared ray coming along the optical axis and leave the same ray to exit out of the prism element along the optical axis, said infrared ray receiver including at least two pair of first infrared ray detection elements and second infrared ray detection elements, said first infrared ray detection elements being configured to output said electric signal according to the received infrared ray, said second infrared ray detection elements being configured to output said electric signal according to the received infrared ray, said electric signal which is output from said second infrared ray detection elements have electrical polarity which is opposite to electrical polarity of the electric signal which is output from said first infrared ray detection elements, each of said two pair of first infrared ray detection elements and second infrared ray detection elements are arranged along a direction perpendicular to the optical axis, both of said second infrared ray detection elements are arranged so that adjacent detection areas have overlapping portions that partially overlap each other, whereby both of said second infrared ray detection elements receive the infrared rays from the overlapping portions, and wherein said infrared ray detector further comprising an outer cover being made of material having a lower thermal conductivity than thermal conductivity of the housing, said outer cover being installed to the housing so as to cover the housing, said prism element is formed so as to be formed with said cover integrally, said plurality of V-shaped grooves being formed along the same direction at said second side of said prism element, said plurality of exit faces being formed along the same direction at said second side of said prism element, and wherein said outer cover is installed to the housing so as to completely cover the housing.