The Modular Bar is perfectly suited for high speed applications. The critical element for your system when you are dealing with a high-speed application is the camera’s exposure time:
The shorter the exposure time, the more contrasted and sharp the image. Also, because of this short exposure time, less light is required to expose the camera’s sensor.
A BRIGHT ILLUMINATION allows the user to reduce the exposure time, and to get a sharp picture.
To ensure no motion blur, you need to ensure that no feature of the part you are inspecting moves more than a single pixel of the camera’s field of view. So you must know the size of the area you are inspecting, the number of pixels in the camera and the size of the single pixel on the FoV. If you know the part is moving, the velocity will be known, most likely in m/min or m/s. The calculation will result in the maximum exposure time.
For example, if the pixel calculation gives you a value of 2ms as the max exposure time, you should aim to significantly reduce this to around 1 to 0.5ms, the lower the better. To enable a very low exposure time you need a very bright light. See an example of this in the calculation below:
- 5MP camera (2600x1900px)
- FoV: 800x600mm
- Part velocity: 20m/min
What is the Exposure Time ?
ANSWER:
- Assuming 2600px in 800mm
- (800mm * 60s) / (2600px * 20,00mm)
Exposure time = 0.9ms Maximum
The Modular Bar comes with OverDrive integrated, which means the light is 4 times more intense when strobed for the first 30ms of the trigger signal.
If the trigger signal is longer than 30ms, the product will automatically revert to continuous working brightness. 30ms is long enough for any vision system to acquire an image, it is rare that the system will go above 5ms.
In OverDrive mode the 250mm Modular Bar can achieve up to 87,000 Lux at 500mm working distance, this can be increased by shortening the working distance, adding additional lights, or increasing the length of the Modular bar.