| 摘要 |
PROBLEM TO BE SOLVED: To provide a reflection-type liquid level indicator, capable of visually observing liquid level position in a liquid container more clearly from a wide-angle direction, through the utilization of external light and more simply confirming correct liquid quantity. SOLUTION: The reflective liquid level indicator of the liquid container 2 is equipped with a window 6 on a side face of the container 2 and has an optical structure, formed on an internal surface of the window so that incident light from an external surface of the window is transmitted through a transmission border surface where the internal surface of the window is in contact with a submerged part of the container; the incident light is reflected at a reflection border surface where the internal surface of the window is in contact with a gaseous part in the container; and the liquid level position 14 can be observed visually from the outside of the liquid container via the window. The optical structure includes a diffraction grating structure 8a, in which fine structures that are continuous in a predetermined direction have the same cross sections provided periodically. COPYRIGHT: (C)2008,JPO&INPIT
|
