An image forming apparatus having an image carrier, a charging unit for charging the image carrier and residual toner on the image carrier, a charging bias applying unit, an electrostatic image forming unit, a developing unit for collecting the residual toner on the image carrier and visualizing the electrostatic image, and a developing bias regulating unit. It is provided that a laser beam converted to have an annular cross-sectional area by using an optical system is deflected for the purpose of producing a radial weld. 3 to 20% of \u2014SO3\u2212 groups contained in the cation exchange membrane. A gate oxide of a certain thickness and another oxide of a different thickness, a greater thickness than the gate oxide, placed in between the body layers but in such way that its shape does not distort the gate oxide in the channel. Consequently, the resonant sensor is able to provide more precise measurements. The semiconductor substrate provides a current carrying electrode for the semiconductor device and one or more internal conductor structures provide a vertical current path between the semiconductor substrate and regions of the HEM device.