Patent ID: 7266321

Claim:
A voltage supply device for developing devices of a color image forming apparatus, the voltage supply device comprising: a printed circuit board (PCB) connected with a high voltage supply source; a plurality of PCB input terminals and a plurality of PCB output terminals provided at the PCB; a plurality of fixed contact point terminals provided to one end of the color developing devices; a plurality of terminal connecting parts connecting the PCB output terminals and the fixed contact point terminals; and a plurality of voltage changeover units comprised of a relay part which selectively applies voltage to the PCB output terminals to selectively supply the voltage from the high voltage supply source to the respective color developing devices, wherein the voltage changeover units are located at an opposite side to the color developing devices with reference to the printed circuit board (PCB), and the relay part comprises: a supporting member provided at the PCB; an electromagnet fixed to the supporting member and magnetized by an electric current; an armature pivotally movable so as to pivot with respect to the supporting member to contact with or spaced apart from the electromagnet according to a magnetic force of the electromagnet during the operation of the electromagnet; and at least a pair of relay input terminal and relay output terminal arranged on a voltage supply path of the PCB, in an opposite position with each other at a predetermined distance, the relay input terminal and the relay output terminal being contacted with, or spaced apart from each other according to contact and non-contact of the armature with the electromagnet so as to switch the power supply accordingly.