Actuator modules with reduced stiffness connections to panels and mobile devices including the same
A panel audio loudspeaker includes an actuator module. The actuator module includes an intermediate layer. The intermediate layer has a voice coil connected to the intermediate layer at a first surface. The actuator module includes a magnet assembly including a plurality of magnets. At least one pair of magnets are separated by an air gap. The actuator module includes a frame connected to the intermediate layer at the first surface, one or more springs connected to the frame and suspending the magnet assembly relative to the frame so that the voice coil extends at least partially into the air gap, and a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface. A stiffness of the spacer at a region of connection to the intermediate layer is less than a stiffness of the intermediate layer at the connection portion.
1. A panel audio loudspeaker comprising:
an actuator module comprising:
an intermediate layer extending in a plane, the intermediate layer having a first surface,
a voice coil connected to the intermediate layer at the first surface, the voice coil defining a coil axis perpendicular to the plane,
wherein the intermediate layer includes:
a printed circuit board, a base-plate, and a pressure sensitive adhesive; and
an aperture that is aligned with the voice coil in a direction perpendicular to the plane, wherein:
the aperture extends through the printed circuit board, the base-plate, and the pressure sensitive adhesive, or
the aperture extends through the printed circuit board and the base-plate, and the aperture does not extend through the pressure sensitive adhesive,
a magnet assembly comprising a plurality of magnets, wherein at least one pair of magnets of the plurality of magnets are separated by an air gap,
a frame connected to the intermediate layer at the first surface,
one or more springs connected to the frame and suspending the magnet assembly relative to the frame and intermediate layer so that the voice coil extends at least partially into the air gap, and
a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface, wherein a stiffness of the spacer at a region of connection to the intermediate layer is less than a stiffness of the intermediate layer at the portion of the intermediate layer; and
a panel attached to the spacer.
2. The panel audio loudspeaker of claim 1 , wherein the voice coil has a length and width in the plane that is substantially the same as a length and width of the spacer in the plane.
3. The panel audio loudspeaker of claim 2 , wherein the voice coil is aligned with the spacer in a direction perpendicular to the plane at the portion of the intermediate layer to which the spacer is connected.
4. The panel audio loudspeaker of claim 1 , wherein the pressure sensitive adhesive forms the second surface of the intermediate layer to which the spacer is connected.
5. The panel audio loudspeaker of claim 1 , wherein:
the actuator module further comprises a ring of compliant material attached on a first side to the panel and on a second, opposite side to the second surface of the intermediate layer,
the ring of compliant material is parallel to the plane and coplanar with the spacer, and
the ring of compliant material surrounds the spacer.
6. The panel audio loudspeaker of claim 5 , wherein the ring of compliant material is aligned with the frame or aligned with the frame and one or more magnets of the magnet assembly in a direction perpendicular to the plane.
7. The panel audio loudspeaker of claim 1 , wherein the panel comprises a display panel.
8. The panel audio loudspeaker of claim 1 , wherein the aperture is c-shaped, and the voice coil is attached to the intermediate layer at a portion of the intermediate layer between ends of the c-shaped aperture.
9. The panel audio loudspeaker of claim 1 , wherein the aperture is o-shaped and separates an inner portion of the intermediate layer from an outer portion of the intermediate layer in the plane.
10. The panel audio loudspeaker of claim 9 , further comprising:
a hood enclosing the magnet assembly and the voice coil in a space defined by the hood and the intermediate layer; and
a supporting member attached to the hood or to at least one of the plurality of magnets of the actuator module.
11. The panel audio loudspeaker of claim 1 , wherein the aperture extends through the printed circuit board, the base-plate, and the pressure sensitive adhesive.
12. The panel audio loudspeaker of claim 1 , wherein:
the aperture extends through the printed circuit board and the base-plate; and
the aperture does not extend through the pressure sensitive adhesive.
13. A mobile device, comprising:
a housing;
a panel audio loudspeaker comprising:
an actuator module comprising:
an intermediate layer extending in a plane, the intermediate layer having a first surface,
a voice coil connected to the intermediate layer at the first surface, the voice coil defining a coil axis perpendicular to the plane,
wherein the intermediate layer includes:
a printed circuit board, a base-plate, and a pressure sensitive adhesive; and
an aperture that is aligned with the voice coil in a direction perpendicular to the plane, wherein:
the aperture extends through the printed circuit board, the base-plate, and the pressure sensitive adhesive, or
the aperture extends through the printed circuit board and the base-plate, and the aperture does not extend through the pressure sensitive adhesive,
a magnet assembly comprising a plurality of magnets, wherein at least one pair of magnets of the plurality of magnets are separated by an air gap,
a frame connected to the intermediate layer at the first surface,
one or more springs connected to the frame and suspending the magnet assembly relative to the frame and intermediate layer so that the voice coil extends at least partially into the air gap, and
a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface, wherein a stiffness of the spacer at a region of connection to the intermediate layer is less than a stiffness of the intermediate layer at the portion of the intermediate layer; and
a panel attached to the spacer; and
an electronic control module electrically coupled to the voice coil and programmed to energize the voice coil to couple vibrations to the panel to produce an audio response from the panel.
14. The mobile device of claim 13 , wherein the mobile device is a mobile phone or a tablet computer.
15. The mobile device of claim 13 , wherein the panel comprises a display panel.
16. A wearable device comprising:
a housing;
a panel audio loudspeaker comprising:
an actuator module comprising:
an intermediate layer extending in a plane, the intermediate layer having a first surface,
a voice coil connected to the intermediate layer at the first surface, the voice coil defining a coil axis perpendicular to the plane,
wherein the intermediate layer includes:
a printed circuit board, a base-plate, and a pressure sensitive adhesive; and
an aperture that is aligned with the voice coil in a direction perpendicular to the plane, wherein:
the aperture extends through the printed circuit board, the base-plate, and the pressure sensitive adhesive, or
the aperture extends through the printed circuit board and the base-plate, and the aperture does not extend through the pressure sensitive adhesive,
a magnet assembly comprising a plurality of magnets, wherein at least one pair of magnets of the plurality of magnets are separated by an air gap,
a frame connected to the intermediate layer at the first surface,
one or more springs connected to the frame and suspending the magnet assembly relative to the frame and intermediate layer so that the voice coil extends at least partially into the air gap, and
a spacer connected along a portion of the intermediate layer at a second surface of the intermediate layer opposite the first surface, wherein a stiffness of the spacer at a region of connection to the intermediate layer is less than a stiffness of the intermediate layer at the portion of the intermediate layer; and
a panel attached to the spacer; and
an electronic control module electrically coupled to the voice coil and programmed to energize the voice coil to couple vibrations to the panel to produce an audio response from the panel.
17. The wearable device of claim 16 , wherein the wearable device is a smart watch or a head-mounted display.
18. The wearable device of claim 16 , wherein the panel comprises a display panel.