| 摘要 |
PURPOSE:To provide encoder assembling structure enabling the easy assembly of an encoder for detecting the speed of a rotor such as a photoreceptor drum, to the rotary shaft of this rotor and also enabling the accurate positioning of a rotating member arid a detecting element forming the encoder. CONSTITUTION:The assembling structure of an encoder formed of a rotating member 12 with plural detection patterns 12c arranged along the circumferential direction, and a pattern detecting element 13 for reading the detection patterns 12c is constituted of the rotating member 12, the pattern detecting element 13, a fitting base 11 to which the pattern detecting element 13 is fixed, and a holder 14 to be fixed to the fitting base 11. An annular step part 15 is formed at one axial end of the rotating member 12, while a regulating hole 16 to be fitted with play to the annular step part 15 is formed at the holder 14. A specified clearance is formed between the fitting base 11 and the rotating member 12, and a regulating protrusion part 18 is further formed to prevent the annular step part 15 and the regulating hole 16 from coming off. |
