AN INFRARED INTENSITY DETECTOR

• US 3,619,614 A
• Filed: 12/19/1969
• Issued: 11/09/1971
• Est. Priority Date: 12/31/1967
• Status: Expired due to Term

• Current Assignee: Eiso Yamaka
• Original Assignee: Eiso Yamaka
• Inventors: Yamaka, Eiso
• Primary Examiner(s): Lawrence, James W.
• Assistant Examiner(s): Frome, Morton J.
• Application Number:
  US04/886,573
• Time in Patent Office: 690 Days
• Field of Search: 250/83.3H,83 73/355
• US Class Current: 250/352
• CPC Class Codes: F16D 2003/22303 Details of ball cages
• CPC Class Codes: F16D 2003/22309 Details of grooves
• CPC Class Codes: F16D 3/2233 where the track is made up of two curves with a point of inflexion in between, i.e. S-track joints
• CPC Class Codes: F16D 3/224 the groove centre-lines in each coupling part lying on a sphere
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: H01C 7/04 having negative temperature coefficient thermometers using resistive elements G01K7/16

Abstract

An infrared intensity detector having a pair of detector elements, one shielded from and the other exposed to an incoming infrared radiation, and a thermostatted black body reference source of a characteristic temperature. The detector elements are made of a semiconductor having a remarkable temperature dependence of resistivity within a limited temperature range around the characteristic temperature. The detector offers increased detection sensitivity and finds a wide variety of applications especially where it is intended to measure an object of relatively low temperature.

Claims

1. An infrared intensity detector for detecting the intensity of an infrared radiation, comPrising a hollow furnace having a resistive film coated on the inside surface thereof, first and second detector elements made of a semiconductive material having a steep negative temperature characteristic in resistivity within a limited temperature range around a critical temperature, said elements being disposed in said furnace and said first element facing infrared radiation to be detected for detecting the intensity thereof and said second element being shielded from the infrared radiation, and a temperature control amplifier for maintaining the temperature in said furnace at said critical temperature connected to said detector element and to said resistive film.

2. An infrared intensity detector according to claim 1, wherein said semiconductive material is a material selected from the group consisting of vanadium dioxide, divanadium trioxide, titanium monoxide and silver sulfide.