Abstract: A rotary encoder scale and a linear encoder scale both made of plastic are provided in operating directions of a printing paper feed motor and a print head driving motor respectively in an inkjet printer. In one or each surface of each of the rotary encoder scale and the linear encoder scale, a metal film is formed in a portion excluding a region to be read by the encoder sensor for reading divisions. The surface of the metal film is grounded to a metal chassis or the like of the inkjet printer. Thus, an inkjet printer for preventing ink mist from adhering thereto can be obtained.

Abstract: An inexpensive and highly-accurate photosensor scale to be disposed in opposition to a reflex-type photosensor for detecting a position of a mobile body moving within a predetermined region, comprising: a base film composed of an industrial photographic film; a slit pattern formed on a surface of said base film; and a reflecting film formed on said slit pattern.

Abstract: An improved plunger type solenoid comprises a solenoid coil, a plunger to be attracted into the solenoid coil, a piston directly or indirectly connected to the plunger and a cylinder filled with oil for containing the piston. The piston is subject to the pressure of the oil, such that the speed of movement of the plunger is widely controlled.