TOF
ToF technology is a way of using sensors to measure distance, a logical function for setting camera characteristics when taking photos or video, but the technology has seen its prospects change a number of times since it began to be used in smartphones in 2014 as the ‘phase detection/laser autofocus’ feature in the LG (066570.KS) G3 and appeared in the Blackberry (BB) PRIV smartphone in 2015, but interest waned until 2018 when a number of Chinese brands included the technology, with Samsung (005930.KS) taking up the TOF cause in 2019 with the Galaxy S and Note series, with it showing up even in Samsung’s lower priced A80 series. Apple joined the TOF cadre in 2019, including it in the iPhone 12 Pro and Pro Max, and it seemed the technology was off to the races.
That optimism waned a bit when Samsung decided to drop the technology from its 2021 smartphone line, which was particularly unusual in that Samsung began producing its own TOF sensors in late 2020, and while others continued to build in TOF hardware and functionality, without the backing of smartphone giant Samsung, interest in TOF seems to have cooled a bit this year. But why would Samsung drop the technology, especially given its ability to self-source and its 2 years of promotion with little explanation other than saying it did not spur developers to come up with applications that used the TOF data and that consumers did not seem to care if it was removed.
That said, we believe it was not that simple an explanation, as there is some nuance that separated Samsung’s TOF ‘flavor’ from the TOF used by Apple, and that difference resulted in relatively poor TOF performance on Samsung’s phones and better performance on others. That nuance is in the two possible ways in what TOF can collect distance data. In the ‘direct’ method, such as is used in Apple’s TOF, a laser is pulsed at intervals less than 5nsec. That light, which is outside of the human visual range, bounces off objects and returns to the device to be captured by a SPAD (Single Photon Avalanche Diode) array. Given the speed of light is a constant, the system can calculate the distance based on how long it took for the reflection to appear; simple math, right? ( L = c 2 φ ω = c 2 φT 2π ), but such systems need lots of pixels to ‘see’ the reflections and must process a considerable amount of data, although they are fast and are able to understand ‘echos’ that occur when the laser bounces off other objects on its way back to the device.
The ‘indirect’ method, the one championed by Samsung, is a bit more esoteric in that the laser sends out a continuous signal and the system measures the ‘phase’ difference between the laser signal and the return, with ‘phase’ meaning a point in each light wave’s cycle.
That optimism waned a bit when Samsung decided to drop the technology from its 2021 smartphone line, which was particularly unusual in that Samsung began producing its own TOF sensors in late 2020, and while others continued to build in TOF hardware and functionality, without the backing of smartphone giant Samsung, interest in TOF seems to have cooled a bit this year. But why would Samsung drop the technology, especially given its ability to self-source and its 2 years of promotion with little explanation other than saying it did not spur developers to come up with applications that used the TOF data and that consumers did not seem to care if it was removed.
That said, we believe it was not that simple an explanation, as there is some nuance that separated Samsung’s TOF ‘flavor’ from the TOF used by Apple, and that difference resulted in relatively poor TOF performance on Samsung’s phones and better performance on others. That nuance is in the two possible ways in what TOF can collect distance data. In the ‘direct’ method, such as is used in Apple’s TOF, a laser is pulsed at intervals less than 5nsec. That light, which is outside of the human visual range, bounces off objects and returns to the device to be captured by a SPAD (Single Photon Avalanche Diode) array. Given the speed of light is a constant, the system can calculate the distance based on how long it took for the reflection to appear; simple math, right? ( L = c 2 φ ω = c 2 φT 2π ), but such systems need lots of pixels to ‘see’ the reflections and must process a considerable amount of data, although they are fast and are able to understand ‘echos’ that occur when the laser bounces off other objects on its way back to the device.
The ‘indirect’ method, the one championed by Samsung, is a bit more esoteric in that the laser sends out a continuous signal and the system measures the ‘phase’ difference between the laser signal and the return, with ‘phase’ meaning a point in each light wave’s cycle.
Light Wave Cycle - Source: Various
This method has less computing demand, which should make the module smaller, a big factor in smartphones, but has more trouble with echoes, which might explain the complaints that we were able to dig up concerning the TOF sensors in the Samsung phones. We believe that Samsung was unable to compete with ‘direct’ method TOF sensors and recognized that the extra cost of the TOF sensor and the poor results were just not worth the inclusion in 2021 models.
Direct TOF modules for Apple are supplied by LG Innotek (011070.KS) and are used in the iPhone and iPad lines, but recent information has indicated that LG Innotek is also supplying TOF sensors that are expected to be used in VR headsets from Apple and Microsoft (MSFT) next year, similar to the ones it supplies to the Oculus VR headset produced by Facebook (FB), with all based on sensor arrays produced by Sony (SNE), with whom Apple has an exclusive contract. While Samsung is said to be developing its own direct TOF sensor, we expect it would have been difficult for Samsung to have justified buying direct TOF sensors from rival Sony when it was producing and promoting its own indirect TOF sensors, thus the abandonment of TOF in the Samsung 2021 smartphone line. If Samsung is able to develop a competitive direct TOF sensor for the 2022 smartphone line, we could see a measured return to the technology for Samsung in 2022, while Apple and others continue to develop additional applications for the technology, pushing out into new products over the next two years.
Direct TOF modules for Apple are supplied by LG Innotek (011070.KS) and are used in the iPhone and iPad lines, but recent information has indicated that LG Innotek is also supplying TOF sensors that are expected to be used in VR headsets from Apple and Microsoft (MSFT) next year, similar to the ones it supplies to the Oculus VR headset produced by Facebook (FB), with all based on sensor arrays produced by Sony (SNE), with whom Apple has an exclusive contract. While Samsung is said to be developing its own direct TOF sensor, we expect it would have been difficult for Samsung to have justified buying direct TOF sensors from rival Sony when it was producing and promoting its own indirect TOF sensors, thus the abandonment of TOF in the Samsung 2021 smartphone line. If Samsung is able to develop a competitive direct TOF sensor for the 2022 smartphone line, we could see a measured return to the technology for Samsung in 2022, while Apple and others continue to develop additional applications for the technology, pushing out into new products over the next two years.
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