Out-of-liquid sensor, and liquid supply device using same

Abstract

The present invention provides a highly universal out-of-liquid sensor that allows an out-of-liquid condition to be accurately detected for a long time, and provides a liquid supply device using the same. The out-of-liquid sensor 1, that is mounted in a liquid supply route for supplying a liquid to a predetermined location and forms a part of the liquid supply route, comprises a light-transmissive tubular body 2, the opening at one end of which is formed into a connecting section 4 capable of communicating with an upstream piping 16 of the liquid supply route, and the opening at the other end of which is formed into a connecting section 5 capable of communicating with a downstream piping 16′ of the liquid supply route, and in which an internal bore section 6 communicating between the two connecting sections 4 and 5 is formed in the liquid-transmitting channel; and also comprises a photosensor 3 mounted on the tubular body 2, the detector 11 of the photosensor 3 being constructed to sense, through the light-transmissive wall surface of the tubular body 2, the presence or absence of a liquid flowing through the internal bore section 6.

Dependencies are inferred from the claim text.