In an active matrix type light emitting device, an upper surface injection type light emitting device in which an anode formed on the upper portion of the organic compound layer becomes an electrode for taking out the light is provided. The first heater is configured to form a primary bubble that ejects fluid from a nozzle associated with the chamber. Reading of the beads is facilitated by restraining the beads in arrays, andor using a focused laser. The system also includes an accounting component for receiving information based on the sub-set of the activity records. The texturing features preferably are uniform in height and diameter, and may be symmetrical or have asymmetrical aspects, so long as bell-shaped profiles are present in the direction of travel of the recording medium, relative to transducing heads. The engaging block moves away from the periphery of the cover when the engaging block is subjected to an external force.