Disclosed is a semiconductor light emitting device. The device includes an ultrasound head which can be freely moved by hand, an ultrasound recording apparatus, an image processing system, and a position detection system. A capacitance calculating circuit samples a voltage at the first node during the measurement node, determines a voltage change rate of the first node during the measurement mode and calculates the capacitance of the device based on the voltage change rate and a value of the one of the charging and discharging current. The second developer supply member moves the developer in the vicinity of the first developer supply member to the first developer supply member.