Sunday, June 21, 2020

Few More iPad LiDAR Pictures

SystemPlus Consulting publishes Apple iPAD Pro 2020 LiDAR module reverse engineering report with few more pictures in addition to many that have already been published:

"This rear 3D sensing module is using the first ever consumer direct Time-of-Flight (dToF) CMOS Image Sensor (CIS) product with in-pixel connection.

The 3D sensing module includes a new generation of Near Infrared (NIR) CIS from Sony with a Single Photon Avalanche Diode (SPAD) array. The sensor features 10 µm long pixels and a resolution of 30 kilopixels. The in-pixel connection is realized between the NIR CIS and the logic wafer using hybrid Direct Bonding Interconnect technology, which is the first time Sony has used 3D stacking for its ToF sensors.

The LiDAR uses a vertical cavity surface emitting laser (VCSEL) coming from Lumentum. The laser is designed to have multiple electrodes connected separately to the emitter array. A new design with mesa contact is used to enhance wafer probe testing.

A wafer level chip scale packaging (WLCSP), five-side molded driver integrated circuit from Texas Instruments generates the pulse and drives the VCSEL power and beam shape. Finally, a new Diffractive Optical Element (DOE) from Himax is assembled on top of the VCSEL to generate a dot pattern.
"

5 comments:

  1. the information regarding the DOE from Hiax is wrong, it should be TSMC.

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  3. Why a DOE in combination with time-of-flight? A DOE creates a spot pattern, like used in structured light but not needed for time-of-flight.
    Can systemplus explain their thinking?

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    1. That thing also has me stumped. I think that there
      is more behind that element than SystemPlus is either aware of or telling publicly. The spot pattern is the individual apertures of the VCSEL itself, the optics just focus and multiply them. However, Himax not only does DOEs, they also advertise some interesting liquid crystal elements on their website. How cool would be a switchable diffusor or a beam-sweeper? Having the energy of the laser focused on a few spots will give you less resolution but more range.

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