UV telecentric lenses offer a high image-resolution in machine vision applications
Opto Engineering Srl of Mantova, Italy, has developed a new family of telecentric lenses - the TC UV Series - that operates in the UV light range. Compared with traditional telecentric lenses, they are able to offer a high image-resolution in machine vision applications.
Common machine-vision lenses and traditional telecentric lenses operate in the visible light range. According to the company, machine vision integrators have been using visible optics because they want their cameras to see what their eyes are able to see. Unfortunately this approach - similar to photography - is limited when applied to systems based on cameras that use very small pixel sizes to achieve high resolution measurement.
In fact, the limiting resolution of a lens is given by the cut-off frequency, the spatial frequency (usually expressed in line pairs/mm) at which the lens is no longer able to yield image contrast information. As the cut-off frequency is inversely proportional to the light wavelength, common machine-vision lenses and telecentric optics operating in the visible range are useless when combined with very small pixel sizes (which can reach 1.75 µm) that are being used more and more in industrial cameras.
UV telecentric lenses can operate efficiently with pixels as small as 2 µm, which allows them to be used successfully in applications that rely on high-resolution cameras. By operating in the 365-425 nm range, they provide a much higher image contrast at high spatial frequencies and are therefore compatible with the tiniest pixel sizes. On the other hand, used in combination with normal cameras, the resolution of these lenses can tolerate object displacements better than visible-light lenses before any image de-focusing becomes evident. This means that the field depth is also increased compared with standard telecentric lenses that operate in the visible light range.
The lenses can work with any kind of UV illuminators operating in the 356-420 nm range, such as ring, coaxial and back-light configurations equipped with UV LEDs. However, the best choice for measurement applications are LTCLUV LED collimated illuminators providing image resolution and field depth enhancement, says Opto Engineering.
UV telecentric lenses, combined with proprietary optical technology developed by the company, enable the TC EDGE imaging technique to be used. This ensures that only those rays which deviate from an object's edge are imaged on the detector plane. Edges are automatically 'extracted' by the lens system without using software algorithms. This approach reveals tiny defects, particles and surface discontinuities that cannot be viewed by any other type of lens system.
Contact:
Claudio Sedazzari
Opto Engineering Srl
Via Cremona 29/2
46100 Mantova
Italy
Phone: +39-376-263525
Fax: +39-376-262432
Email: claudio.sedazzari@opto-engineering.com
Web: http://www.opto-engineering.com
Common machine-vision lenses and traditional telecentric lenses operate in the visible light range. According to the company, machine vision integrators have been using visible optics because they want their cameras to see what their eyes are able to see. Unfortunately this approach - similar to photography - is limited when applied to systems based on cameras that use very small pixel sizes to achieve high resolution measurement.
In fact, the limiting resolution of a lens is given by the cut-off frequency, the spatial frequency (usually expressed in line pairs/mm) at which the lens is no longer able to yield image contrast information. As the cut-off frequency is inversely proportional to the light wavelength, common machine-vision lenses and telecentric optics operating in the visible range are useless when combined with very small pixel sizes (which can reach 1.75 µm) that are being used more and more in industrial cameras.
UV telecentric lenses can operate efficiently with pixels as small as 2 µm, which allows them to be used successfully in applications that rely on high-resolution cameras. By operating in the 365-425 nm range, they provide a much higher image contrast at high spatial frequencies and are therefore compatible with the tiniest pixel sizes. On the other hand, used in combination with normal cameras, the resolution of these lenses can tolerate object displacements better than visible-light lenses before any image de-focusing becomes evident. This means that the field depth is also increased compared with standard telecentric lenses that operate in the visible light range.
The lenses can work with any kind of UV illuminators operating in the 356-420 nm range, such as ring, coaxial and back-light configurations equipped with UV LEDs. However, the best choice for measurement applications are LTCLUV LED collimated illuminators providing image resolution and field depth enhancement, says Opto Engineering.
UV telecentric lenses, combined with proprietary optical technology developed by the company, enable the TC EDGE imaging technique to be used. This ensures that only those rays which deviate from an object's edge are imaged on the detector plane. Edges are automatically 'extracted' by the lens system without using software algorithms. This approach reveals tiny defects, particles and surface discontinuities that cannot be viewed by any other type of lens system.
Contact:
Claudio Sedazzari
Opto Engineering Srl
Via Cremona 29/2
46100 Mantova
Italy
Phone: +39-376-263525
Fax: +39-376-262432
Email: claudio.sedazzari@opto-engineering.com
Web: http://www.opto-engineering.com
