Ma y visio devices ca ot ely o ambie t light. I spectio cells u lights out. Pa ki g st uctu es a d pe imete s ope ate th oughout the ight. Biomet ic eade s must behave the same at oo a d mid ight. Medical a d labo ato y i st ume ts eed illumi atio that does ot distu b the subject. I each case, the desig e adds ea -i f a ed LEDs, which the huma eye ba ely otices, a d a i came a that espo ds to that light a d delive s a co siste t image ega dless of the time of day. Resolutio aises the value of that app oach. Fi e su face defects, small, p i ted ma ks, dista t faces, a d the textu e of a i is all ewa d mo e pixels, so i te est i high- esolutio ea i f a ed imagi g keeps g owi g.
High esolutio also makes ea i f a ed imagi g ha de . A 20MP se so o a 1/1.8 i ch fo mat has 1.4 mic o pixels, a d small pixels collect fewe photo s i a give exposu e tha la ge o es. Silico also espo ds mo e weakly as wavele gth i c eases, so a sce e lit at 940 m etu s less sig al tha the same sce e lit at 850 m. The combi atio of small pixels a d a lo ge wavele gth is the most dema di g case a desig e ca choose. A module desc ibed o ly as NIR-se sitive, without ami g the ba d o the esolutio , does ot tell a i teg ato whethe it will wo k at 20MP u de a 940 m illumi ato , a d a module tested o ly at low esolutio says little about the high esolutio case.
Focus adds a quiete p oblem. Le ses ef act diffe e t wavele gths by diffe e t amou ts, so the pla e of best focus fo ea i f a ed light sits at a slightly diffe e t dista ce tha fo visible light. A le s focused i daylight ca look soft u de a 850 m illumi ato , a d at 20MP the soft ess is easy to see, because the se so esolves the blu . Devices that u i visible light by day a d ea i f a ed by ight face the p oblem eve y eve i g. A fixed focus setti g is always a comp omise betwee the two.
Ba dwidth a d exposu e complete the pictu e. A 20MP f ame is la ge, a d a USB li k limits how ma y such f ames a ive each seco d. I dim ea -i f a ed sce es, the exposu e time may eed to be lo g, a d the exposu e ca ot exceed the f ame pe iod without lowe i g the f ame ate. Teams that ig o e this coupli g discove late that thei chose esolutio , exposu e, a d f ame ate ca ot all be met togethe , which fo ces cha ges to lighti g, optics, o softwa e afte ha dwa e is built.
The Falco -2020CRH is built o the O semi Hype Lux LP AR2020, a 20MP (5120 x 3840) colo olli g shutte se so with a 1/1.8 i ch fo mat a d 1.4 mic o pixels. The se so is a low- oise CMOS desig that suppo ts e ha ced dy amic a ge a d excelle t ea -i f a ed espo se at 850 m a d 940 m, a d it also suppo ts Wake o Motio . Vadzo has validated the module u de ea -i f a ed illumi atio i both ba ds. This makes the module a Excelle t NIR USB 3.2 Ge 1 Came a i the se se that matte s to a i teg ato , because the espo se was co fi med at the esolutio a d the wavele gths the p oduct will use, ot o ly at a co ve ie t test poi t.
Autofocus add esses the focus shift di ectly. The module ca ies a S-Mou t VCM le s holde with a 73 DFOV le s by default, a d autofocus is o e of the UVC co t ols it exposes alo gside b ight ess, exposu e, sha p ess, satu atio , gai , a d gamma. Whe the illumi atio cha ges f om visible to ea i f a ed, the host ca equest a ew focus so the image etu s to its best sha p ess fo the ew ba d. This does ot elimi ate the physics of ch omatic focus shift, but it lets the le s follow the shift i stead of livi g with a pe ma e t comp omise. Teams that use a le s co ected fo ea i f a ed will see a smalle shift, a d they still be efit f om autofocus fo cha ges i subject dista ce.
The module suppo ts esolutio co t ol, YUYV a d MJPEG fo mats, a softwa e image captu e t igge , dy amic ROI, gai a d exposu e co t ol, a d a ti-flicke fo 50Hz a d 60Hz lighti g. Exposu e ca be set ma ually th ough softwa e o left to auto exposu e. I USB 3.2 Ge 1 mode, the suppo ted video modes u as follows. VGA eaches 120 f ames pe seco d i UYVY a d 100 i MJPEG. Full HD eaches 60 i both fo mats. 4K eaches 15 i UYVY a d 30 i MJPEG. The 13MP mode eaches 10 a d 20, a d the full 20MP mode eaches 5 i UYVY a d 10 i MJPEG. Whe the module u s o a USB 2.0 po t, ates d op, with 4K at 2 f ames pe seco d i UYVY a d 15 i MJPEG, a d 20MP at 1 a d 5. These figu es guide pla i g, si ce the exposu e time i a dim sce e ca ot exceed the f ame pe iod at the chose mode. Fo example, a sce e that eeds a 200 milliseco d exposu e ca ot u faste tha 5 f ames pe seco d, whateve the i te face allows, so teams should estimate exposu e ea ly a d pick a mode whose f ame pe iod accommodates it.
Illumi ato i teg atio is the i teg ato ‘s job, a d the module offe s p actical hooks. A six-pi GPIO co ecto p ovides o e digital i put a d o e digital output, both 1.8-volt tole a t a d co ected di ectly to the module co t olle , a d Vadzo ca e able fu the li es th ough its customizatio p og am. Because the logic level is 1.8 volts, a exte al d ive stage is o mally eeded to switch a LED illumi ato . Two status LEDs show whethe the module is powe ed with o st eami g o actively st eami g. The module is USB-powe ed, d awi g betwee 1.05 W a d 1.75 W at 5 volts, which leaves oom withi the USB budget but ot fo a la ge illumi ato , so the illumi ato should have its ow supply. Eye safety of the illumi ato emai s the espo sibility of the device make .
Mecha ically, the module measu es 38 mm by 38 mm, co ve tible to 30 mm by 30 mm, a d weighs 13 g ams without the le s. It ope ates f om mi us 30 deg ees C to 70 deg ees C with 20 to 80 pe ce t elative humidity, o -co de si g, which cove s most i doo a d shelte ed outdoo i stallatio s.
