Abstract: A device for controlling the quality of microdroplets deposited on a substrate comprises a light source for illuminating the substrate which has the microdroplets deposited thereon. An image generator is provided for receiving the light which has been produced by the light source, fallen through the substrate or reflected by the substrate, so as to generate an image. Furthermore, an identifier and an analyzer are provided for analyzing the generated image with respect to patterns created in said image as a result of a refractive effect produced by microdroplets deposited on the substrate.