The history of endoscopy has gone through the process from rigid optical endoscope to fiber-optic endoscope to electronic endoscope. With the rapid development of semiconductor and computer technology, in 1983, americans first invented the endoscope hole detector and applied it in aviation, which is regarded as the third milestone in the development of endoscope. Instead of transmitting images through an optical lens or fiber optic fiber, an electronic endoscope converts light energy into electricity using a CCD, an optoelectronic coupled element mounted on the endoscope's tip, called a microcamera.

The quality of image has a direct impact on the use of endoscope, and also marks the continuous improvement and improvement of endoscope hole detector technology. The appearance of electronic endoscope improves the image quality to a new level, so it is widely used in aviation.

Image quality is the essence of endoscope borescope instrument and the most important performance indicators, and using electronic technology to image synthesis and processing technology, image quality can be divided into the resolution (resolution, is determined by the number of pixels), color reducibility (realistic) and observation of comfort (image stability, contrast and brightness, etc.). Decision is the core component of electronic endoscope image quality optoelectronic coupled devices (CCD), it is like the heart of the electronic endoscope and its basic structure is on the sensitive semiconductor wafers with high precision of lithography split out hundreds of thousands of grid, each grid represent an imaging element, the more pixels, the higher the resolution of the image, the more clear picture.