Electronic device with sound generator

1. An electronic device, comprises:

a display screen;

a middle frame assembled with the display screen;

a supporting arm opposed to the middle frame;

a piezoelectric actuator fixed on the supporting arm;

a bulge disposed between the middle frame and the supporting arm, the bulge being fixed to the middle frame, and connected to one end of the supporting arm.

2. The electronic device as described in claim 1 , wherein a frontal projected area of the bulge on the middle frame is less than a frontal projected area of the piezoelectric actuator on the middle frame.

3. The electronic device as described in claim 2 , wherein a cantilever beam structure is formed between the supporting arm and the bulge.

4. The electronic device as described in claim 3 , wherein the supporting arm is a long strip.

5. The electronic device as described in claim 1 , wherein the supporting arm includes a lower surface facing the middle frame and an upper surface opposite to the lower surface, the piezoelectric actuator is fixed on the upper surface.

6. The electronic device as described in claim 1 , wherein the bulge and the supporting arm are integrally formed.

7. The electronic device as described in claim 1 , wherein the bulge and the middle frame are integrally formed.

8. The electronic device as described in claim 5 further including a weight, wherein the weight is located at another end of the supporting arm away from the bulge.

9. The electronic device as described in claim 8 , wherein the weight is fixed to the upper surface of the supporting arm.

10. The electronic device as described in claim 9 , wherein the weight keeps a distance from the piezoelectric actuator.