| Abstract: | Background: The diagnostic capability of a video‐endoscope has been remarkably enhanced by using a high pixel count charge‐coupled device (CCD) and is getting closer to that of the stereomicroscope as its image quality is improved. From this standpoint, the authors have been developing high‐resolution magnifying video‐endoscopes. Methods: There are two methods available to increase the resolution of a video‐endoscope: (i) use a CCD with large pixel number and (ii) optically magnify the image impinging on the CCD. Since the video‐endoscope using a 410 Kilo (K) pixel count CCD was introduced in 1993, the authors have been developing a video‐endoscope using a large pixel count number CCD in pursuit of obtaining better image quality and resolution. Also, the technological innovations in CCD manufacturing have allowed CCDs to become much smaller in size with higher pixel numbers. As the CCD size decreases, the distal part of a video‐endoscope can be made thinner. With respect to optical magnification, two methods are available, the fixed close‐focusing system and variable focus. Results: With combined use of the variable focus magnification and the electronic magnification, a magnification more than × 100 can be achieved on a 14″ television monitor with higher resolution power and wider depth of field. Conclusions: The images captured by the latest magnifying video‐endoscope prove that the image quality of video‐endoscopy is improving and is approaching the diagnostic capability of the stereomicroscope. |
