A microscope contains a light source that emits illuminating light, and an apparatus that generates an illumination pattern in an image field of the microscope. Due to this, it is possible to electronically connect the IC chip to the multilayer printed circuit board without using lead members and a sealing resin. During the warming-time, which is until the timer times-out with the ignition switch turned to the off state, the control circuit controls power to the heater to maintain the driving battery in a warmed-up condition. Thus, an abnormally overheated state of one or more of the switching elements or the battery cell leads to an increase in the resistance of the positive temperature coefficient thermistor causing shut-off of the switching element thereby protecting the battery pack.