Abstract: A head-mounted wearable device (HMWD) with a form factor of eyeglasses incorporates hinges between a front frame and temples. The hinges provide a fully enclosed passage for a flexible printed circuit (FPC). The FPC allows electrical connectivity between devices in the front frame and in the temple. The hinge includes a cam device that provides a biasing force that allows the temples to remain in one of four configurations: closed, transit, neutral, and maximum neutral. When in the transit configuration the biasing force provided by the cam device tends to move the temples towards the closed configuration. When in the maximum neutral configuration the biasing force provided by the cam device tends to move the temples towards the neutral configuration. During use, this biasing of the temples provides a gentle clamping force that assists in maintaining the HMWD on the user's head.

Abstract: A head-mounted wearable device (HMWD) provides audio output using acoustic quadrupole units (AQU). The AQU produces an acoustic pattern having a first region and a second region. The first region has a first phase and the second region has a second phase that is opposite the first phase. A major axis extending through the regions is directed generally upwards from the ear canal of the user. The ear of the user is within the first region. The second region is directed upward. Bystanders are within an acoustically null region of the acoustic pattern. The acoustically null region is perpendicular to the major axis. Within the acoustically null region, the sound intensity is reduced due to destructive interference between the first phase and the second phase. As a result, the user wearing the HMWD is able hear audio output while audio amplitude perceived by the bystanders is significantly reduced.

Abstract: A head-mounted wearable device (HMWD) with a form factor of eyeglasses incorporates a compact audio module with transducers that may be operated as an acoustic dipole or acoustic quadrupole. The audio module provides ducts that convey sound with a particular phase from a transducer to particular output ports. The phase of sound emitted from a first output port is opposite to the phase of sound emitted from a second output port. The audio module may include a pair of transducers, enabling operation as an acoustic dipole or quadrupole. The ducts are integrated into elements of the structure of the audio module, minimizing the overall size of the audio module.

Abstract: A head-mounted wearable device (HMWD) may be fashioned that includes temples that pass near each ear of the user. A temple may incorporate a bone conduction speaker (BCS) to provide audio output to the user. During wear, a portion of the BCS is in physical contact with a head of the user to transfer the vibrations from the BCS to the user. To accommodate different head shapes and sizes, a head contact piece may be mounted to the BCS. The user may add, remove, or swap the head contact piece from an assortment of such pieces to find a profile that is comfortable to the wearer and improves performance of the BCS. The head contact piece may be magnetically affixed, allowing for easy changeout.

Abstract: A head-mounted wearable device (HMWD) includes a bone conduction speaker (BCS) to provide audio output to a user wearing the HMWD. The BCS may be mounted within a recess of a temple of the HMWD. During wear a portion of the BCS is in physical contact with a head of the user. In one implementation, a head contact piece may be mounted to the side of the BCS that is proximate to the head. The head contact piece is contoured to maximize the contact area with the head, and may have a cross section that is approximately wedge shaped, with a thicker portion of the wedge proximate to the front of the HMWD. The BCS may include low damping elements to provide protection to the BCS from damage and improve performance, as well as high damping elements to reduce the transfer of vibrations from the BCS to the temple.

Abstract: The present invention discloses a mixer circuit for mixing two input signals by source-coupled MOS transistors and outputting a mixed result. A duty cycle controlling MOS transistor is connected to a source of each source-coupled MOS transistor in series. A duty cycle controlling pulse is applied to a gate of the duty cycle controlling MOS transistor. The duty cycle controlling pulse has a phase shift of ?90 degrees with respect to a controlling pulse applied to the gate of the source-coupled MOS transistor connected with the duty cycle controlling MOS transistor in series. An AND-combination of the duty cycles of the two controlling pulses applied to the gates of the two MOS transistors connected in series can be controlled at 25%. Comparing to the conventional mixer circuit having a switch control duty cycle of 50%, the present invention achieves the effects of increasing the gain and reducing the noise figure.