Abstract: A high-reliability optical reading apparatus for reading a latent image mark capable of accurately reading the code information of a latent image mark. The optical reading apparatus comprises a light-projecting light member for projecting on a surface of the latent image mark, the light having a wavelength to excite a fluorescent substance contained in the latent image mark having desired information; and a light-receiving member for receiving fluorescence emitted from the surface of the latent image mark. A range in which the latent image mark can be read is formed by setting a point at which the optical axis of the light-projecting member and that of the light-receiving member intersect with each other as a reference. An intersection angle between the two optical axes is preferably in the range of from 10.degree. to 40.degree..

Abstract: A media particle size separating apparatus and method are disclosed for use with a slurry blast cabinet. The system is capable of continuous operation so that under sized blast media particles and fines can be separated out of the slurry along with debris from the blasting operation on a continuous basis. An upwardly open partition divided hopper receives spent slurry from the blasting cabinet to flow through at least two chambers in the hopper to a pump returning the slurry and sized media to the blasting cabinet and nozzles therein. Unusable fines collected in one chamber of the hopper are drawn off through a drain valve.