Patent ID: 8308357

Claim:
A fluorescent temperature sensor for producing a temperature signal from fluorescent light of a fluorescent material that has been optically excited, comprising: a light emitting device projecting light onto the fluorescent material; a photoreceiving element receiving fluorescent light that is emitted from the fluorescent material; a case fitting a module unit containing both the photoreceiving element and the light emitting device on a substrate, and provided with a connector receiving portion and a plug portion; and a single light propagating medium conducting, between the light emitting device and the photoreceiving element at one end and the fluorescent material at an opposite end, both the light that is emitted from the light emitting device and the fluorescent light that is emitted from the fluorescent material, wherein the module unit disposes the photoreceiving element across a specific gap from the light emitting device, wherein the light propagating medium is connected to the case so that a core of the light propagating medium is positioned within the range of directional characteristics of the light emitting device, and the photoreceiving element is positioned within the range of an aperture angle of the light propagating medium, wherein the case and the single light propagating medium are connected at a position wherein the light that is emitted by the light emitting device is received within the single light propagating medium and the fluorescent light that is emitted from the fluorescent material is incident on the photoreceiving element from within the single light propagating medium, and wherein the light emitting device directly projects the light onto the single light propagating medium and the photoreceiving element directly receives the fluorescent light from the single light propagating medium, wherein the single light propagating medium is provided with a connector that is connected to the connector receiving portion of the case, the connector including a ferrule that is plugged into the plug portion of the case, and into which the single light propagating medium is inserted and integrated, a guide member that fits around the ferrule and slides in a direction of an axis of the guide member to hold the ferrule, and a coil spring that applies a force on the ferrule towards a tip end portion of the ferrule, wherein the module unit is provided with a window portion that is positioned between the plug portion of the case, and the light emitting device and the photoreceiving element, facing the light emitting device and the photoreceiving element, and wherein, a tip end of the ferrule is pushed by force of the coil spring toward the window portion of the module unit and comes into contact with the window portion when the single light propagating medium receives the light emitted from the light emitting device and projects the fluorescent light emitted from the fluorescent material onto the photoreceiving element.