Figure 3: Pixel sizes on sensors and overall sensor sizes have changed in size to accommodate higher resolutions.
formats but are also finding new ways to decrease pixel sizes without sacrificing image quality. One new sensor example is Sony’s 4th generation Pregius S 24.5 MP IMX530 CMOS, a 4/3” sensor (diagonal 19.3mm) with a 2.74µm pixel size (37% smaller pixel size vs. 3.45µm).
However, as pixel sizes decrease and sensor sizes increase, significant changes to the optical designs must be made to make full use of increased performance. This requires imaging lens designs to incorporate additional optical elements, making imaging lenses larger in volume and heavier in weight. These two constraints put a strain on lens designers to create lenses with mounts larger than the C-mount and more robust and reliable than the consumer F-mount.
Lens mount types such as the TFL and TFL-II mounts feature compact flange distances and larger diameters for sensor formats like the APS-C, APS-H, and other fullframe sensors. These mounts are also threaded types that feature superior stability, support for heavy lenses, and alignment reliability over bayonet types like the F-mount.
Figure 4: The TFL and TFL-II Mounts accommodate a larger maximum
sensor diagonal.
Sensor manufacturers are releasing the next generation of CMOS sensors with extremely high resolutions. The Canon 120MXS CMOS sensor features 120MP and pixels 2,2 µm in size and the Canon 2U250MRXS CMOS features 250MP and pixels of 1,5 µm. Both of these sensors have pixels with sizes much smaller than the industry’s typical pixel sizes. The new 4th generation of Sony Pregius sensors feature a smaller form-factor and an improved imaging performance of about 1,7X. These sensors also feature pixel sizes that have decreased from 3,45 µm to 2,74 µm.
As machine vision applications demand higher resolution, CMOS manufacturers will have to continue reducing the size of individual pixels and increasing the overall size of sensors to improve image quality and effective resolution.
