Fuel property detection device

A fuel property detection device comprising:

• a light guiding member disposed partially in contact with fuel, the light guiding member being made of a translucent material;
• a light source disposed to allow light emitted therefrom to enter the light guiding member;
• a photoreceptor disposed to receive measurement light which is the light emitted from the light source and proceeding in the light guiding member, the photoreceptor being configured to output a detection signal by receiving the measurement light;
• and
• a detection portion adapted to detect a property of the fuel based on the detection signal output from the photoreceptor,
• wherein the light guiding member includes a light emitting surface through which the measurement light is emitted from the light guiding member into the fuel, a light incident surface through which the measurement light emitted from the light emitting surface and passing through the fuel enters again the light guiding member, and a reflecting surface at which the measurement light incident from the light incident surface is reflected toward the photoreceptor,
• wherein the light incident surface and the light emitting surface are opposite to each other to have a space between the light emitting surface and the light incident surface in the light guiding member, and
• wherein the space is provided to be filled with the fuel, and the reflecting surface is in direct contact with the fuel.