Smart Sensors BMT-20 Iris Scanner
The BMT-20 is a binoculars-type iris biometrics imaging device that simultaneously and quickly captures highest quality iris biometric images. Easy to use, the system can be reliably positioned by the subject with minimal instructions, or by an operator with the aid of positioning feedback LEDs on the top of the imager s housing.
Key Features
The optical design includes utilizing highest quality optics and long internal optical path, which allows the BMT-20 to exceed industry standards for image quality as specified by ISO in the 19794-6 document. The standard is 4.0 lp/mm at 60% contrast ratio.
The proprietary and patented single sensor design interleaves left and right iris images for simultaneous capture. By utilizing only a single sensor, power consumption through the USB connection is minimized. This allows for optimized NIR illumination, resulting in the shortest exposure times possible, thereby minimizing any potential for motion blurring.
The BMT-20 can capture iris image pairs from subjects with inter- pupillary distances as small as 4.0 cm, which is the minimum distance for a child of 5 years old. This makes the BMT-20 ideal for enrollment of all subjects within all national identity programs.
Meeting this very high standard means that the BMT-20 is highly resistant to contamination by very small airborne particles such as dust and dirt, such as would be commonly found in harsh non-conditioned enrollment environments. Stringently tested against this standard, this feature will provide extended life and high reliability. Other systems only meet the lesser IP54 specification.
Internal, white light emitting diodes (LEDs) are turned on just prior to imaging to constrict the subject s pupil for iris biometric image capture, providing ideally sized pupils for optimal iris biometric identification and authentication.
Motion detection
System calculates eye motion relative to the system, and waits until subject meets motion threshold (which is adjustable) in order to assure there is no adverse motion blurring of images.
The BMT-20 can be operated in two modes: first by the subject himself after being giving short and easy to understand instructions. The system can also be operated by a trained operator, who will position the device based on external color LED s to center the system over the subject s eyes.
- Red : Device is too high
- Blue : Device is too low
- Green : Device position is OK
A position sensor detects if the system is upside down, preventing capture of images that can be reversed, left and right. This assures that all iris biometric samples are exactly as intended.
Technical Specification:
Dimensions | 219x161x58mm (8.6x6.3x2.3inches) |
Weight | 680 g (1.5 lbs) |
MTF / spatial resolution | Exceeds 4.0 lp/mm @ > 60% contrast |
Pixel resolution | 18.4 to 20 pixels/mm |
Iris image pixel resolution | 640 x 480 pixels |
Image output | Meets ISO 19794-6 |
Capture distance (to forehead) | 0 to 10 mm (0.0 to 0.4 inches) |
Optical path distance | 350 to 380 mm |
Depth of field | 30 mm (1.2 inches) |
Inter-pupillary distance covered | 40 to 90mm (1.6 to 3.5 inches) |
Time of capture | Around 1 second, typical, from time of head placement |
IR illumination for iris imaging | Dual LED: wavelengths of 850 nm nominal (~ 60%); and 750 nm nominal (~ 40%) |
Internal LED for pupil contraction | Broadband visible (white) |
External LED indications for operator assisted positioning |
Red: Device position is too high Blue: Device position is too low Green: Device position is OK White: Image capture in progress |
Operating temperature | range 0 to 50 C |
Humidity | 10 to 90% RH, non-condensing |
Eye safety standard | IEC 62471, IEC 60825-1 |
Durability | IP64 intrusion prevention standard |
Interface | USB 2.0 High Speed |
Power | USB 2.0 (500 mA at 5V), No additional power required |
PC hardware and OS requirements |
Intel  Atom  or above processor Windows XP 32 bit or above Linux OS version of SDK and drivers in progress |
Other certifications | CE , FCC, USB-IF, India STQC, RoHS, WHQL |