Abstract: A substrate-cleaning apparatus includes a transmission unit, a wet cleaning unit and a dry cleaning unit. The transmission unit includes a movable clamp for clamping a substrate that includes a face without covering the face of the substrate. The wet cleaning unit includes a wiper and a liquid pump. The wiper includes a strip of cleaning cloth and an abutting element for pressing the cleaning cloth against the face of the substrate. The liquid pump sends cleaning liquid to the abutting element that in turn sends the cleaning liquid to the cleaning cloth when the abutting element presses the cleaning cloth against the face of the substrate. The dry cleaning unit includes a wiper comprising a strip of cleaning cloth for wiping dry the face of the substrate without leaving any water mark on the face.

Abstract: An optical screening device includes a box and a light source. The box includes two chambers. The first chamber includes an incident passageway made with an exit. The second chamber includes a reflection passageway made with an entrance and an exit. The light source is inserted in the first chamber and adapted for casting incident light onto a first face of an inspected object located out of the box through the exit of the incident passageway so that primary reflected light goes into the second chamber from the first face of the inspected object via the entrance of the reflection passageway and goes out of the second chamber through the exit of the reflection passageway. The entrance of the reflection passageway is made with small width to allow only the primary reflected light to enter the second chamber.