Coaxial (Incident) Illumination

Illumination is sent down the viewing axis, striking the object and reflecting back into the lens, and on to the image plane. The most common design uses the last optic in the viewing lens as the condenser lens. If well controlled, it provides an excellent image of a flat specular object.

Image: Coaxial Illumination

Image: Zoom 6000 / Fiber Optic Coax

Zoom 6000 / Fiber Optic Coax
Image: Zoom 6000 / LED Coax

Zoom 6000 / LED Coax


Image: Coaxial Illumination Image: Coaxial Illumination Image: Coaxial Illumination



The LED Coax Illuminators are available in 1 watt and 5 watt versions. The 1 watt comes in white, warm white (less blue), and red. The 5 watt comes in the two whites, no red, green, cyan, blue, and royal blue. Available power drivers include a manual, digital / with computer control, and an OEM board for computer control for the 1 watt, and a computer control and OEM board for the 5 watt.



Coaxial Operating Restrictions

When internal coaxial illumination is combined with a standard zoom system, there are certain conditions that must be met to guarantee satisfactory performance, as defined by no dark corners at the image plane.

Because the last lens of the system acts as a condenser, the maximum illuminated area on the object is restricted to approximately 11mm for the Zoom 6000 and 20.5mm for the 12X zoom. The 12X Telecentric Zoom is a special case where the illumination will cover the 50mm field of view.

To prevent dark corners, the overall system mag, at the sensor, must be such that this maximum circle of illumination will extend beyond the diagonal of an area sensor or length of a line scan.

Example: Zoom 6000, 1/2" format(4.8X6.4mm, 8mm diagonal), object size = 10 x 7mm

The Wizard calculates that it will take .64X to portray the entire object on the sensor. However, the circle of light is only .64 * 11 = 7.04mm diameter, which will not overlap an 8mm diagonal sensor, therefore there will be dark corners - and the wizard will come up with a "no match".

Adjustments:

Need 8 / 11 or .72X magnification to fill an 8mm diagonal

Change the object dimension such that the Wizard comes up with a .72X mag requirement (in this case 8/.72 = 11.11 instead of 10). The light will now fill the sensor, corner to corner, and the wizard will be happy.

Normally, with a zoom system, one locates at low mag and then "zooms up" to see detail. If you are willing to live with dark corners in the "locate" mode, then put in the acceptable larger dimension (11.11), and pick the solution where the lowest available mag allows you to reach .64X. As you "zoom up", the mag will increase and the dark corners will disappear.

Or you could go to the 12X zoom where the useable illuminated spot is 20.5mm. Here, the original .64X mag would produce a lighted spot on the sensor of .64 * 20.5 = 13.12mm, which is greater than the 8mm sensor diagonal, and the wizard, again, would be happy.

Precise Eye (coax)

While the Precise Eye lacks the zoom feature, it has the same 11mm useable illumination feature from the Zoom 6000. Therefore, the magnification, multiplied by 11mm, must equal or exceed the diagonal of the sensor (or length of the line scan).