It is an object of the present invention to provide a technique for manufacturing a highly reliable display device at low cost with high yield. A first dry gas flow is purged from a first mass flow controller through a saturator to produce a near-saturated gas flow. toy car, comprises a body, wheels for moving the body on a surface, and an electric motor provided in the body for driving the wheels. No active power amplifier is required. In addition, previously stored programs may be viewed at accelerated or decelerated speed, or repeated or portions reviewed, to allow the user to review such in other than real time. The purpose of the invention is to propose a hysteresis driver with improved adjustability.