Below find links to cameras available though misumi.com.tw. These are 8.5mm x 8.5mm CCTV cameras that operate on 5V-12V. These products take some time to ship to the US, but there are many comparable products available more locally. What is important is that the eye camera be B/W, and that the scene camera be color and that they be very small. These are the specific cameras we use.
The same applies for the lenses we use. The B/W eye camera must have an IR sensitive lens (many are IR blocking) so that it can perceive the reflection from the IR LEDs that illuminate the eye. The lens for the color scene camera is less critical, but wide angle is recommended.
The important thing about the glasses is that they be light. We have very lightweight frames made by Wileyx, but we also have a model built on trial frames so that we can insert lenses for those subjects that require a prescription.
The circuit is fairly simple. If you are using cameras that can operate with 5V, all you need is an LED driver and a trim pot (and, of course, LEDs). If your camera needs 12V, you will need to either use a separate, dedicated 12V supply for the cameras, or else include a voltage converter circuit to turn the 5V source into 12V.
This is used to power the LEDs. It is very important not to exceed 100mA at the output of pin 6. It will cause the LEDs to catch on fire. This output current is controlled by the trim pot. USE CAUTION!
- 10K trim pot x1
- Recom RCD-24-0.30 x1
- infra-red LED (i.e. OSRAM SFH 4451) x2
5 to 12 volt converter
This is necessary if your cameras are powered by 12V. The voltage converter IC is a little hard to find, but so are 5V security cameras.
This is not the best schematic I've ever made. Eagle doesn't have a library for the VInfinity chips and I didn't feel like making one. The pin labels (FC, C+, etc.) should be ignored, they correspond to another IC. The pin numbers are, however, correct. You can also consult the VWRBS2-D5-S12-SIP data sheet for the same circuit.
- 100μF cap x2
- 22μF cap x1
- 4.7μH choke x1
- VInfinity VWRBS2-D5-S12-SIP x1
Cables and Connectors
- 5mm female barrel jacks X3
- USB to 5mm barrel, or USB jack (for power supply to the circuit)
- 5mm male barrel jacks X4
- male BNC crimp (or an old male BNC x1
- female BNC jack x1
- Low noise coaxial wire (for making cables)
- RCA cable X2
- RCA to USB (for connecting to a computer)
- garden variety electrical wire
- 5v source (battery or wall wart)
- Project box (to house the circuitry
- 16 gauge copper wire (for mounting the cameras)
- super glue
- heat shrink
- bread board and spacers