According to a patent reported by Patently Apple, Apple is researching a new optical audio transmission technology that may be applied to the rumored Apple MR glasses.
In the patent illustration, there is a set of optical transmitters and receivers between the glasses and earplugs for optical signal transmission; and the earplugs in the illustration also have an additional radio frequency (Bluetooth) transceiver. Receiver for Bluetooth audio reception between mobile phone and earbuds.
Normally, Apple’s ear-worn devices such as AirPods use the Bluetooth transmission protocol. Due to the limited bandwidth of Bluetooth transmission, AirPods are limited to the highly compressed AAC codec, and the audio signal must be compressed and decoded before it can be obtained. Therefore, although Apple Music supports lossless audio, you still cannot get the details in the music through AirPods.
In May last year, Apple officially announced that Apple Music would adopt the new lossless audio encoding format ALAC to provide lossless music comparable to CD quality. Subsequently, support for Dolby Atmos spatial audio and lossless audio was implemented in iOS 14.6.
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Optical provides a wider audio transmission bandwidth than Bluetooth, which can support lossless and high-resolution audio files that Bluetooth audio cannot achieve.
However, optical audio transmission has some disadvantages. It can only work over a very short range and there must be no line of sight obstruction between the transmitter and receiver. Therefore, for the headband described in the patent, Optical audio transmission between the wearable device and the earbuds is possible, but transmission between the phone in your pocket and the earbuds is not, and the phone needs to be taken out.
Therefore, the patent also adds a radio frequency transceiver to solve the above problems. If the optical signal transmission fails, the earbuds can use Bluetooth transmission instead, but lossless audio cannot be achieved during Bluetooth transmission.
Wanli’s brief comment: Any new technology has limitations. So, although this patent solves one problem, there is a new problem that is not actually completely solved. As for whether the upcoming AirPods Pro 2 will use this technology, it is still relatively unclear at present.
Writer: Zhou Sensen/Shenzhen Bay