A telecentric lens is a special optical system in which the main ray is parallel to the optical axis of the lens.

Even if the WD (working distance ⇒ distance between the subject and the optical system) changes, the magnification does not change, and the feature is that the entire work surface can be photographed from the front. It is suitable for capturing images of objects with individual differences and variations in height and objects with depth. It is used for FA and is ideal for visual inspection and high-precision positioning. The lens diameter is one size larger than the object size.

We design and manufacture the optimum telecentric lens customized according to the customer's system requirements.

Main applications

Telecentric lenses can be used for the following purposes.

  • Garbage inspection of glass substrate
  • Reading 2D coordinates
  • High speed image processing
  • Surface inspection of silicon wafer

Features of telecentric lenses

  • The telecentric lens has a constant magnification regardless of the distance between the subject and the optical system (Example 1).
  • Less image distortion due to parallax

  • Ideal for precision inspection and measurement of parts with height differences and depth!
  • Highly accurate positioning is possible!
  • Strong against work shake and vibration!

Types of telecentric lenses

Object side telecentric lens

It is a lens with a telecentric structure only on the object side. Basically, the size of the image does not change even if the work moves up and down.
The accuracy may be inferior to that of double-sided telecentric, but it has the advantage of being able to be designed compactly.

Both sides telecentric lens

Both the object side and the image side are telecentric lenses.
Even if there are variations on the work side or the mounting accuracy of the camera and sensor is poor, there is an advantage that it can be measured with higher accuracy than a normal telecentric lens.
The overall length of the lens may be longer than that of the telecentric lens on the object side.

For more details, please check on https://www.dzoptics.com/en/machine-vision/telecentric-lens/