tag:blogger.com,1999:blog-19092890.post3329863916091982782..comments2024-03-28T11:30:04.427+02:00Comments on Image Sensors World: Infineon Cooperates with PMD on Automotive ToF ImagersVladimir Koifmanhttp://www.blogger.com/profile/01800020176563544699noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-19092890.post-87358411092505322292012-06-11T18:00:32.689+03:002012-06-11T18:00:32.689+03:00Well, these 3D sensors have been around and under ...Well, these 3D sensors have been around and under investigation in the automation and automotive industry for several years. Most of them still suffer from limitations due to ambient light or low re-emission levels from certain surfaces. Further, in the interview, which was originally in German, a range of 50m is stated. Did Google Translate simply swap meters for feet? Just 50ft range wouldn't be impressive.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-19092890.post-27594903161377721662012-06-07T15:37:52.907+03:002012-06-07T15:37:52.907+03:00I gues, controlling light source means probably ju...I gues, controlling light source means probably just emitting more optical power, burst mode operation or so.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-19092890.post-7754248281150982572012-06-07T15:10:33.300+03:002012-06-07T15:10:33.300+03:00Yang, you are correct that you cannot suppress the...Yang, you are correct that you cannot suppress the shot noise from the ambient light component. The problem with ambient light is that it uses up the full well capacity of the pixel. So, you subtract the "d.c." signal of the ambient light differentially thru some switch cap circuit so as to preserve pixel signal capacity. Subtracting the large signal still leaves shot noise in the pixel, not to mention additional noise and FPN from the subtraction circuit. More modulation signal intensity can improve SNR. There are other strategies for dealing with ambient light, esp. since we can control the light source. Someday, perhaps, we will publish our strategy for the case of small pixels. Still, at large distance, it is hard to get enough optical power in mobile applications (not counting cars of course).Eric R Fossumhttps://www.blogger.com/profile/09740612324630105312noreply@blogger.comtag:blogger.com,1999:blog-19092890.post-13903556548475828732012-06-07T14:32:07.408+03:002012-06-07T14:32:07.408+03:00Eric, I've question on ambient light cancellat...Eric, I've question on ambient light cancellation. Basically we can use somewhat differential sensing for ambient light continous component cancellation. But tthe shot noise from ambient light can not be removed. A large signal energy is still needed to overcome the shot noise from strong ambient light. What is your comment on this issue please ?<br /><br />-yang niAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-19092890.post-65879763008457339512012-06-07T14:19:05.071+03:002012-06-07T14:19:05.071+03:00I still wonder if an active 3D sensor using LED be...I still wonder if an active 3D sensor using LED become defacto standard.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-19092890.post-89535576400578278782012-06-07T13:41:24.176+03:002012-06-07T13:41:24.176+03:00I will make a technical comment since you asked. I...I will make a technical comment since you asked. I think PMD uses 45x45 um pixels - 2025 um^2. The Samsung RGBZ reported at 2012 ISSCC uses a 2.25x9 um pixel - 20.25 um^2, exactly 1% the size of the PMD pixel. Anyone doing image sensors knows what an impact this has on camera performance. The PMD sensor has 100k pixels, and the Samsung RGBZ sensor was 172k pixels.<br /><br />For large pixels, the problem is demodulation contrast (DC) so short transit times are critical. Large pixels also result in large chips and large optics and hence large size. Not so good for embedded applications such as mobile or displays, and thus at this time confined to a bit more of a niche market.<br /><br />For small pixels DC is less important at the same modulation frequency because transit time varies (typically) as L^2 and the problem is more of QE and read noise. For small pixels, one does not have the luxury of layout room for (straight-forward) in-pixel ambient light cancellation circuitry so sunlight suppression is more of a challenge.<br /><br />So, really, two very different design spaces between what we have worked on at Samsung and what is reported here.Eric R Fossumhttps://www.blogger.com/profile/09740612324630105312noreply@blogger.comtag:blogger.com,1999:blog-19092890.post-56879173776878852202012-06-07T01:51:12.667+03:002012-06-07T01:51:12.667+03:00Hey, it is hardly "my" work at Samsung. ...Hey, it is hardly "my" work at Samsung. For sure our published work has been a team effort. I am architecture and pixel concepts, but details, process, circuit design, and ISP all come from other team members.<br /><br />Anyway, looks like a nice image.Eric R Fossumhttps://www.blogger.com/profile/09740612324630105312noreply@blogger.comtag:blogger.com,1999:blog-19092890.post-55741971934498166842012-06-06T23:14:58.213+03:002012-06-06T23:14:58.213+03:00How compare this to Eric Fossum's work at Sams...How compare this to Eric Fossum's work at Samsung??Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-19092890.post-74785098659111153872012-06-06T23:00:38.464+03:002012-06-06T23:00:38.464+03:00Nice achievement! What is the LED power for 50 fee...Nice achievement! What is the LED power for 50 feet distance??Anonymousnoreply@blogger.com