The present invention relates to an image pick-up apparatus having a focus detection mechanism capable of improving an AF speed at low costs and in a space-saving way without adding any new mechanism or optical system and ensuring an accurate focus adjustment and capable of preventing a picture-taking image quality being deteriorated. The apparatus may include a buffer coupled to receive incoming data from a data source. Though a spring for generating resonance is combined with the displacer, a spring for generating resonance for the piston is eliminated. The container has a protrusion in a bottom center thereof to support the removable incense holder and to allow it to rise above the surface of the ground while it is being used as a censer. The transmission interface includes a transmission controller and two transmission interfaces. Optical waveguide devices are machined by laser ablation using a combination of IR and UV lasers.