A conveying device includes a cylindrical first roller, a cylindrical second roller that has a surface hardness higher than a surface hardness of the first roller, and a belt placed in a state surrounding either the first roller or the second roller. The disclosed VSCAL devices and production methods provide for an active region having a quantum well structure grown on GaAs-containing substrates, thus providing processing compatibility for light having wavelength in the range 1. The fluorescent ballast circuit provides a change in the output voltage applied to the lamp load in response to a change in the ballast drive signal frequency. The second dielectric layer is etched to form a third trench. The accelerometers may detect acceleration in the direction of vehicle travel andor lateral acceleration. A layer of drive circuitry is deposited on the wafer substrate, and subsequent etchant layers are deposited on the drive circuitry to define a nozzle chamber with walls and a roof structure defining an ink ejection port.