Optotune liquid lenses – 5 case examples for machine vision

Optotune tunable lenses

Optotune & Gardasoft liquid lens controlsLiquid lens technology, with its ability to change focus within the order of milliseconds is opening up a host of new applications in both machine vision and the life sciences.  It is gaining growing interest from a wide cross section of applications and easily adapts to standard machine vision lenses.

Liquid lens technology alone provides nice solutions, but when combined with advanced controls, many more applications can be solved.

To learn the fundamentals of liquid lens technology and download a comprehensive white paper read our previous blog HERE. 

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In this blog, we will highlight several case application areas for liquid lens technology.

Case 1:  Applications requiring various focus points and extended depth of field:  This does cover many applications, such as logistics, packaging and code reading in packaging.  Optotune Liquid lenses provide the ability to have pre-set focus points, auto-focus or utilize distance sensors for feedback to the lens.  In the example below, 2 presets can be programmed and toggled to read 2D codes at various heights essentially extending the depth of field.

extended DOF

Case 2:  3D imagery of transparent materials / Hyperfocal (Extended DOF Images:  When image stackingusing an Optotune liquid lens in conjunction with a Gardasoft TR-CL180 controller, sequence of images can be taken with the focus point stepped between each image.  This technique is known as focus stacking.   This will build up a 3D image of transparent environments such as cell tissue or liquid for analysis.  This can also be used to find particles suspended in liquids.

image stacking for cells

A Z-stack of images can also be used to extract 3D data (depth of focus) and compute a hyper-focus or extended depth of field (EFOF) image.

The EDOF technique requires tacking a stack of individual well focused images which have preferably been synchronized with one flash per image.  An example is show below with the rendered hyper focus image shown at right.

Hyperfocus imageCase 3:  Lens inspection:  Liquid lenses can be used to inspect lenses, such as those in cell phones for dust and scratches looking through the lens stack.

Optotune liquid lens stack imageFor this application, a liquid lens is used in conjunction with a telescentric lens taking images through different heights of the lens stack.  

Case 4:  Bottle / Container inspection:  Optotune Liquid lenses can be used to facilitate image bottom’s of glass bottles or containers of various heights.

In this example, the camera is consistently at the neck of the bottle, but the bottom is at different heights.  optotune lens - bottle inspection

Case 5:  Large surface inspections with variation in height:  Items ranging from PCB’s to LCD’s are not flat, have various component heights and need to be inspected at high magnification (typically using lenses with minimal DOF).  Optotune Liquid lenses are a perfect solution using preset focus points.

pcb inspection

Machine Vision applications using Optotune Liquid lenses and controller are endless!

These applications are just the tip of the iceberg and many more exist, but this will give you a good idea of capabilities.   Gardasoft TR-CL controllers are fully GigE Vision compliant, so any compatible GigE Vision client image processing software such as Cognex VisionPro, Teledyne Dalsa Sherlock or National Instruments LABVIEW can be used easily.

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1st Vision’s sales engineers have over 100 years of combined experience to assist in your camera selection.  With a large portfolio of lenses, cables, NIC card and industrial computers, we can provide a full vision solution!

Contact us to help in the specification and providing pricing

Ph:  978-474-0044  /  info@1stvision.com  / www.1stvision.com

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Learn how liquid lenses keep continuous focus on machine vision cameras when the working distance changes.

Optotune focus tunable lenses
Optotune lenses
Optotune lenses

Optotune lenses solve a machine vision industry problem! 

IDS Imaging camera with Optotune lens

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Machine Vision applications requiring the inspection of objects at various heights can become a challenge as normal lens have limited depth of field.  Objects outside of the depth of field become out of focus, limiting the vision application.  Historically, a lens with motorized focus adjustment would be implemented adding complexity, cost and long cycle times.  In reality, this challenge is applicable to any imaging application requiring refocusing due to various lens working distances.

Optotune Focus tuneable lenses solves this problem eliminating motorized zoom lenses or manual intervention.

Click here NOW for full detail specifications on tunable lenses

Adding an Optotune tunable liquid lens to the optical system on a standard C-mount lens and camera, allows refocusing of the imaging system on the fly.   When used in conjunction with distance sensors, its possible to  inspect objects of various heights, refocusing within 15 milli-seconds.

For example, vision systems using 8mm to 50mm focal length lenses can be equipped with a tuneable lens in the front, typically mounted on the filter thread.  In this configuration it is possible to focus from infinity down to about 100mm  or less if spacers are added.

This solution can be applied to industrial machine vision applications, ophthalmology, laser, microscopy, postal, packaging and laser applications to name a few.

Contact 1stVision for a quote on Optotunes Tunable lenses

Technology 411
 Optotune’s focus tunable lenses are shape-changing lenses based on a combination of optical fluids and a polymer membrane. The core element consists of a container, which is filled with an optical liquid and sealed off with a thin, elastic polymer membrane. A circular ring that pushes onto the center of the membrane shapes the tunable lens. The deflection of the membrane and with that the radius of the lens can be changed by pushing the ring towards the membrane or by exerting a pressure to the outer part of the membrane or by pumping liquid into or out of the container.
Watch this video to see the Optotune liquid lens in action

Advantages

A change in lens radius of several micrometers can have the same optical effect as moving the entire lens several centimeters. In turn there are several advantages

  • Optical systems can be designed more compact, oftentimes with less lenses and usually with less or no translational movement.
  • Large working distance ranges can be achieved
  • Eliminate expensive mechanical actuators resulting in a more robust design, which can be completely closed so that no dust can enter.  Essentially no moving parts for long life cycles (> 1B cycles)
  • Weight and volume is reduced in the system.
  • Low power consumption.
  • Fast response time of systems, down to the order of milliseconds.
  • Easy installation and remote focus control
  • Advanced controls for very accurate and repeatable control of the lens using Gardasofts TR-CL180 controllers

Want to know more?  Download Optotunes comprehensive white paper here 

This white paper will review the overall principles of tunable lenses, response times, wavefront quality, drive methods, and applications.

Contact 1stVision for a quote on Optotunes lenses and discuss an overall solution with cameras, lenses and lighting if required. 

UPDATE:  Video showing some great demo’s from the Stuttgart Vision show in 2018