| 摘要 |
PURPOSE:To enable miniaturization of dimensions and positive detection of liquid level, by accommodating light emitting and receiving elements in the same housing and installing on one side of the housing reflecting plates in an opposed manner. CONSTITUTION:In case when a level of ink 8 is located in a lower position A of a photo-sensor 10, a ray of light from a light emitting element 11 is reflected by a reflecting plate 16 and reach a light-receiving element 12 through air between a housing 9 and a reflecting plate 16. When the level of ink 8 rises up to a line B position, a ray of light of the light emitting element 11 reflected by the reflecting plate 16 reaches the light-receiving element 12 through ink 8 existing between the housing 9 and the reflecting plate 16. A magnitude of light reaching the element 12 is greater than that when the ray of light passes through air on its light path and consequently, by the quantity of light received by the light receiving element 12, it is possible to detect whether the ink level 8 is located above the photo-sensor 10 or not. |
