This is a PNRLM 2.0X optical inspection unit made by PlusTek Co., Ltd. in Korea that I found at a surplus equipment dealer. The main attraction unit of this unit was an unidentified and unbranded lens that looks suspiciously like a Printing-Nikkor (PN). Serious macro photographers will recognize the Printing-Nikkor (PN) name for high-end aberration-free performance. The resolving power of the PN is extremely high, 320 lp/mm on axis, with strict apochromatic correction, and 0% distortion, and 0% corner shading. PlusTek used this OEM built-to-order 95mm Printing-Nikkor lens mounted in reverse for 2x magnification with motor-driven focus. The size and weight of the PNRLM 2.0X unit is surprising, I believe the weight was 17.3 kg or 38 pounds. According to PlusTek, the PNRLM 2.0X units were sold as part of an Automated Optical Inspection (AOI) system. These types of systems are primarily used to find defects in printed circuit board (PCBAs), LCD, OLED, and microLED (micro-LED, mLED, or µLED) panel assemblies.
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Custom OEM Printing-Nikkor Line Scan Lens
PlusTek uses an OEM built-to-order Printing-Nikkor 95mm f/2.8A (PN95A) lens. This is a special version made by Nikon Rayfact for PlusTek. The Printing-Nikkor label is not used on this lens, this is normal for OEM units, and the serial number follows the other three PN95 lenses that I own. The PlusTek part number PNRLM 2.0X lettering on the side of the main unit is an obvious giveaway, as the PN stands for Printing-Nikkor. I have never seen this variant before and there is zero information available from Rayfact or Nikon.
This is the 4th version of the 95mm Printing-Nikkor lens I’ve tested, the 5th variant that I am aware of, and the second custom OEM custom version that I've seen. This line scan version, I’ll call it the PN95L, is a different physically than the other 3 versions I own. The total length of the lens is longer than the other PN95 versions and the central optical section is also longer by about 10mm from front to rear glass. My first thought was that this a Printing-Nikkor 105mm (PN105) or a custom 1.75x Printing-Nikkor but the focal length measures in at 94.9mm which indicates that this is a 95mm f/2.8 2x lens according to the Rayfact catalog.
The custom OEM Printing-Nikkor 95mm 2x (PN95L) lens in the center, the Nikon Rayfact 2x (R2x) on the left, and the Nikon Printing-Nikkor 95mm F2.8A (PN95) on the right. The front trim rings have been removed for each lens.
R2X: 94.4mm total length (TL)
PN95L: 114mm TL
PN95: 91.4mm TL
PN105: 104.2mm (not pictured) TL
For more information follow this link for the full PN95 test here on Closeuphotography.com: https://www.closeuphotography.com/printing-nikkor-95mm-test
Piranha Line Scan Camera
The camera used in this system is a Teledyne DALSA Piranha HS-80-08k80 TDI. This type of camera uses uses multiple exposures of the same (moving) object for better image quality in low light installations. The technology is called TDI (time delay and integration). The sensor is a 8196 x 96 pixel unit with a 7 μm pixel pitch, and is capable of 640 megapixels/second throughput. The camera uses a standard M72 Mount and a standard Dalsa back focal distance of 6.56mm. This Piranha model is discontinued but I was able to find a price range of $11,891.00 - $15,453.00 USD body only on a 2015 Dalsa price list.
The main center section is solid aluminum with small area at the base to clear the focus motor.
Optical sensors on the right and the focus motor and drive screw at the rear.
The dual micrometer setup right above the camera mount is used to set the θ (theta) Sensor Alignment (angular position) of ± 0.2 °, to align the inspection field to the line scan sensor. This is a single axis version, PlusTek also made a two axis version with motor driven magnification and focus.
Beware Buying From Surplus Dealers
This PNRLM 2.0X line scan unit was sourced from a industrial surplus dealer, but before you open a browser start searching the internet, there are some things you need to be aware of. Salvage or surplus dealers buy equipment at auctions for a fraction of the original cost, and make quick profit by flipping the items, but quite often they don’t actually know what they are selling, this is especially true when dealing with optics. For example, this seller was completely unaware that they were selling a Printing-Nikkor since this OEM version does not carry a Rayfact or Nikon label. In any case buying from salvage or surplus dealer directly is a gamble. Units are usually sold for parts only, no returns, and its impossible to know the condition of optics for example before you order, and some vendors specially state they cannot judge the condition of optics, so you need to be aware.
Machine Vision Terms
TDI (time delay and integration)
TDI is a type of line scan camera that uses a type of scanning that accumulating multiple exposures of the same (moving) object, effectively increasing the time available to collect incident light. The object motion is synchronized with the exposures to ensure a sharp image. This increases sensitivity allowing much greater scanning speeds in low light, or allows reduced lighting levels (and costs) at conventional speeds.
AOI (Automated Optical Inspection)
The PNRLM 2.0X unit is designed to be part of an Automated Optical Inspection (AOI) system. These types of systems are primarily used to find defects in printed circuit board assemblies (PCBAs), LCD, OLED, and microLED (micro-LED, mLED, or µLED) panel inspection. Roughly 99 million micro LED chips are required for an 8K TV panel and a 0.5% defect rate means that an average 520,000 defective chips on average per panel. These defective chips need to be identified as soon as possible in advance before they are transferred to a panel.
PCBA (Printed Circuit Board Assembly)
This is just a finished printed circuit board (PCB) used in electronics manufacturing, using the older thru-Hole Technology (THT) Assembly Process or the current Surface Mount Technology (SMT) process.
LCD (Liquid Crystal Display)
Type of flat panel display that uses the light-modulating properties of liquid crystals combined with polarizers. LCDs do not emit light directly, instead using a backlight or reflector to produce images in color. Common in all types of electronic displays.
LED (light-emitting diode)
Semiconductor device that emits infrared or visible light when charged with an electric current. Used in Machine vision systems for lighting sources shaped into different types of lighting for different requirements.
OEM (Original Equipment Manufacturer)
This is a manufacturer that sells products to a another company that puts these products under its own branding.
OLED (organic light-emitting diode or organic LED)
Light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light. Common in modern electronics.
MicroLED (micro-LED, mLED, or µLED)
This is an emerging flat-panel display technology using microscopic LEDs that form individual pixel elements. Compared to widespread LCD technology, microLED displays offer better contrast, response times, and energy efficiency.
Links for more information
Printing-Nikkor 95mm f/2.8 test here on Closeuphotography.com: