3.6 Optical and optomechanical components

If you wish to test your idea of target-wisely customised imager, it can be built combining a machine vision sensor with optical or optomechanical components. There exists various of components to choose from.

Extension tubes (Figure 1) are useful for creating more complex prototype imagers than a basic sensor and a lens. With extension tubes, the optomechanical components can be mounted together.

Different band-pass filters (Figure 2), beam splitters (Figure 3) and lenses can be used to produce, for instance, a simple two-channel spectral imager.

Figure 2. Series of band-pass filters, FWHM 10 nm. These filters vary between 380 -700nm.

Figure 3. This beam splitter divides the incoming light 50:50 to two sensors. This way, we can create a MV system that captures the target scene at the same time with two cameras. The sensors can be different, and we can use different filters to gain more detailed information from the target.

While designing such a system, it is valuable to understand that the system’s parameters will change depending on where the extension is added. For example, suppose the extension is placed between the lens and the sensor. In that case, the image-side focal length increases, decreasing the minimal working distance and field of view, magnifying the object (Greivenkamp 2004).

Examples in the future posts

As an example of special imager, a spectral camera typically consists of an optomechanical components, lenses and a sensor. The optomechanical component can be a prism or mechanical, dispersing the incoming light to wavelengths. We will later discuss over the spectral imagers and spend some time getting known with the dispersive components and their operating principles.

Found something useful? Wish to cite? This post is based on my dissertation. For citations and more information, click here to see the scientific version of it.