Bloomberg: Apple Relaxes Face ID Projector Tolerances

Bloomberg publishes some info about iPhone X depth camera production difficulties:

"The 3-D sensor has three key elements: a dot projector, flood illuminator and infrared camera. The flood illuminator beams infrared light, which the camera uses to establish the presence of a face. The projector then flashes 30,000 dots onto the face which the phone uses to decide whether to unlock the home screen. The system uses a two-stage process because the dot projector makes big computational demands and would rapidly drain the battery if activated as frequently as the flood illuminator.

The dot projector is at the heart of Apple’s production problems. Precision is key. If the microscopic components are off by even several microns, a fraction of a hair’s breadth, the technology might not work properly, according to people with knowledge of the situation.

The fragility of the components created problems for LG Innotek Co. and Sharp Corp., both of which struggled to combine the laser and lens to make dot projectors. To boost the number of usable dot projectors and accelerate production, Apple relaxed some of the specifications for Face ID, according to a person with knowledge of the process. As a result, it took less time to test completed modules, one of the major sticking points, the person said.

To make matters worse, Apple lost one of its laser suppliers early on. Finisar Corp. failed to meet Apple’s specifications in time for the start of production. That left Apple reliant on fewer laser suppliers: Lumentum Holdings Inc. and II-VI Inc."