Open earphones

1. An open earphone comprising:

a sound producer including a transducer and a housing accommodating the transducer; and

an ear hook, the ear hook including a first portion and a second portion, the first portion being hung between an ear and a head of a user, the second portion extending towards a side of the ear that is away from the head and connecting the sound producer, the sound producer being fixed in a position near an ear canal, and an opening of the ear canal being not blocked by the sound producer; wherein

the ear hook and the sound producer form a first projection on a first plane, the first projection including an outer contour, a first end contour, an inner contour and a second end contour,

the outer contour, the first end contour, the second end contour and a tangent segment connecting the first end contour and the second end contour jointly define a first closed curve, and

when the open earphone is in a non-wearing state, a first area of the first closed curve is in a range of 1000 mm 2 to 1500 mm 2 .

2. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a ratio of the first area to a projection area of the ear on a sagittal plane of a human body is in a range of 0.7 to 0.95.

3. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a ratio of a projection area of the sound producer on the first plane to the first area is in a range of 0.25 to 0.4.

4. The open earphone of claim 1 , wherein an end of the first portion of the ear hook away from the second portion includes a battery compartment, the first end contour being a projection contour of a free end of the battery compartment on the first plane;

when the open earphone is in the non-wearing state, a ratio of a projection area of the battery compartment on the first plane to the first area is in a range of 0.15 to 0.25.

5. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a distance between a position of a mass center of the open earphone and a polar point of the ear hook in a first direction is in a range of 24 mm to 31 mm, the first direction being perpendicular to a long axis direction of the sound producer in the first projection.

6. The open earphone of claim 5 , wherein when the open earphone is in the non-wearing state, an angle between a line connecting the position of the mass center of the open earphone and the polar point of the ear hook in the first direction and the long axis of the sound producer in the first projection is in a range of 55° to 85°.

7. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a distance between a position of a mass center of the open earphone and an upper apex of the ear hook is in a range of 25 mm to 32.5 mm.

8. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a distance between a position of a mass center of the open earphone and a bottom side surface of the sound producer is in a range of 3 mm to 5.5 mm.

9. The open earphone of claim 1 , wherein

the tangent segment is tangent to the first end contour at a first tangent point,

the tangent segment is tangent to the second end contour at a second tangent point, and

when the open earphone is in the non-wearing state, an area of a triangle formed by the first tangent point, the second tangent point, and a polar point of the ear hook in a first direction is in a range of 150 mm 2 to 190 mm 2 .

10. The open earphone of claim 9 , wherein a length of the tangent segment is in a range of 14 mm to 22 mm.

11. The open earphone of claim 9 , wherein when the open earphone is in the non-wearing state, a distance between the first tangent point and the polar point is in a range of 35 mm to 55 mm.

12. The open earphone of claim 9 , wherein in the triangle formed by the first tangent point, the second tangent point, and the polar point, an angle formed at the first tangent point is in a range of 20° to 35°.

13. The open earphone of claim 9 , wherein in the triangle formed by the first tangent point, the second tangent point, and the polar point, an angle formed at the second tangent point is in a range of 120° to 150°.

14. The open earphone of claim 9 , wherein in the triangle formed by the first tangent point, the second tangent point, and the polar point, an angle formed at the polar point is between 10° and 22°.

15. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, the inner contour, the first end contour, the second end contour, and the tangent segment connecting the first end contour and the second end contour jointly define a third dosed curve, a third area of the third dosed curve being in a range of 300 mm 2 to 500 mm 2 .

16. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a maximum distance between a position of a mass center of the ear hook and the outer contour is in a range of 15 mm to 35 mm in a direction of a long axis of a projection of the sound producer on the first plane.

17. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a distance between a position of a mass center of the open earphone and a long axis of a projection of the sound producer on the first plane is in a range of 5 mm to 10 mm.

18. The open earphone of claim 1 , wherein when the open earphone is in the non-wearing state, a relative distance of a mass center of the sound producer relative to the mass center of the ear hook is in a range of 20 mm to 35 mm.

19. The open earphone of claim 4 , wherein when the open earphone is in the non-wearing state, a relative distance of a mass center of the battery compartment relative to the mass center of the ear hook is in a range of 35 mm to 55 mm.

20. The open earphone of claim 4 , wherein when the open earphone is in the non-wearing state, a relative distance of a mass center of the sound producer relative to the mass center of the battery compartment is in a range of 15 mm to 30 mm.