Magnetically one-side driven planar transducer with improved electro-magnetic circuit

A single-ended planar transducer device for generating a sound signal based on an electrical signal, comprising:

• a ferrous frame defining a back plate portion, a side portion, and a flange portion;
• first and second primary rows of primary magnets;
• a diaphragm;
• a conductive trace formed on the diaphragm;
• wherein
• the frame supports
• the two primary rows adjacent to each other and between first and second opposing side portions of the flange to define
• a core set of primary rows, where a primary magnetic field is established between the primary rows in the at least one core set, and
• first and second return rows in the first and second opposing side portions, where first and second edge magnetic fields are established between the first and second primary rows and the first and second return rows, respectively;
• wherein
• a perimeter of the diaphragm is secured to the frame such that
• a first portion of the trace is arranged at least partly within each primary magnetic field, and
• a second portion of the trace is arranged at least partly within the first edge magnetic field, and
• a third portion of the trace is arranged at least partly within the second edge magnetic field;
• and
• the electrical signal is applied to the conductive trace such that the primary and first and second magnetic fields cause movement of the conductive trace and the diaphragm, thereby generating the sound signal.

A method of generating a sound signal based on an electrical signal, comprising the steps of:

• providing a frame;
• securing a perimeter portion of a diaphragm to the frame to define a frame chamber;
• securing a plurality primary magnets to the frame within the frame chamber in at least two primary rows such that two primary rows adjacent are arranged to each other to define at least one core set comprising no more than two primary rows, where a primary magnetic field is established between the primary rows in the at least one core set;
• arranging at least one return row comprising at least one return structure adjacent to the at least one core set such that a return magnetic field is established between each return row and any primary row adjacent thereto;
• forming a conductive trace on the diaphragm such that
• a first portion of the trace is arranged at least partly within each primary magnetic field, and
• at least a second portion of the trace is arranged at least partly within each return magnetic field;
• and
• applying the electrical signal to the conductive trace such that the primary and secondary fields to cause movement of the conductive trace and the diaphragm to generate the sound signal.