Fixed focus and movable focus

For our IN5+(Optics300), the measuring range and the measuring diameter are uniquely determined. This type of lens is called fixed focus. An example of this light path diagram is shown.

In contrast, the movable focus type allows the measurement spot diameter to be narrowed down optimally at any measurement distance. When the measurement object is small, such a movable focus type is convenient. The 140 Series is a product tailored to such applications.

In this case, change the focal length by moving the lens back and forth like a camera lens.
When the lens is extended, the focus position moves to the short focus side and when the lens is pushed in, it moves to the long focus side.

This is shown in one figure below. This is a sample IPE140/MB5 Optics1-PE.
The short focus side is the focal length 105mm and the measured spot diameter is φ2.4mm, while the long focus side is the focal length 155mm and the measured spot diameter is φ4.1mm. From this figure, you can know the measurement spot diameter that can be optimally narrowed down within this focal length range.

In addition, a movable focus type is also available for the optical fiber type lens.