To provide a driving transmission apparatus which can reduce noise generation by reducing a shock when an oscillation portion is switched to a transmission state.

Each gear in a gear train composed of a driving gear 21, an oscillating gear 22, and a driven gear 23 is rotatably supported by means of shafts 31, 32, 33 supported by a supporting plate 1. The supporting plate 1 is provided with a slot 2 allowing the shaft 32 of the oscillating gear 22 to oscillate and rotate. A small projection 51 is formed at the intermediate position of the inside peripheral surface of the slot 2. In the course of the movement of the oscillating gear 22 in the direction of the engagement with the driving gear 21 by the operation of a spring 6, the shaft 32 is brought into contact with the small projection 51 and the moving speed of the shaft 32 is slowed down. Because the oscillating gear 22 is pushed against the driving gear 21 by the pulling force of the spring 6 in that state, the noise caused by the collision is reduced.