JPS5484764A - Liquid level inspector within vessel - Google Patents

Abstract

PURPOSE:To perform accurate inspection of liquid levels without effect on the vibrations of a solid state camera by cutting the portion where the transmitted light of a light transmittable vessel including liquid level is unnecessary with a shutter and letting the light received in the solid state camera provided with image sensing elements. CONSTITUTION:The vessel 30 being conveyed by a belt 28 or the like is radiated by the luminous flux from a lighting device 34 and the transmitted light inclusive liquid level is scanned and picked up by a solid state camera 36 built-in with MOS type diode element array or the like. The diode elements having received the transmitted light above the liquid level generates pulses of a high level. Hence, if the pulse number above the threshold value outputted by the camera 36 is counted, the liquid level is detected. In this case, the transmitted light of the vessel 30 is partly cut off by a slit 70 which corresponds to the permissible upper and lower limits of the liquid level, thus the unnecessary transmitted light owing to the intricate shapes near the liquid level of the vessel does not enter the camera 36 and the accurate inspection of the liquid level may be performed without being affected by the change in the optical axis owing to the vibrations of the camera.