Autoclaveable miniaturized video endoscopes with simplified flip-chip assembly

Abstract

Miniaturized video endoscopes with an imager located at the distal end and a simplified opto-mechanical layout are presented. They are based on a CMOS imager with 650 x 650 pixels of 2.8 ?m pitch and provide straight view with 75 ° and 110 ° field of view at f/4.3. They have an outer diameter of 3 mm including the shell and a length of approx. 8 mm. The optics consist of polymer lenses in combination with a GRIN and a dispensed lens. Using a simple flip chip assembly, optical axis alignment better than 10 ?m and a contrast of 30 % at 90 LP/mm was achieved. The 75 ° FOV system was sealed at the front window using a solderjetting technology, providing 10-9 mbar*l/s leakage rates even after several autoclave cycles

Precision glass molding process enhancing the expanding of chip-on-tip endoscopes

“…It's reported that the sensor can reach a resolution up to 190 line pairs/mm with pixel dimensions of 2.8 µm and 422 500 pixels in an image diameter of 2.6 mm in a research from Fraunhofer IOF, especially the camera module has only 3 mm in diameter and 6.4 mm in length 3 . Figure 2: Structure example of the chip-on-tip 3 Although the optical system in the Figure 2 is made from polymer, glass lenses can have a stronger performance in such as ophthalmology and robotic endoscopy procedures 4 . Moreover, the optical surfaces are tended to be aspherical surfaces in order to achieve the specified optical performance in a structure as compact as possible in the endoscope 3,4 .…”

“…Figure 2: Structure example of the chip-on-tip 3 Although the optical system in the Figure 2 is made from polymer, glass lenses can have a stronger performance in such as ophthalmology and robotic endoscopy procedures 4 . Moreover, the optical surfaces are tended to be aspherical surfaces in order to achieve the specified optical performance in a structure as compact as possible in the endoscope 3,4 .…”