Patent Number: 6,254,531

Title: Electronic-endoscope light quantity controlling apparatus

Abstract: The present invention is an electronic endoscope apparatus that can appropriately compensate for the lack of light quantity caused by a delayed response from a shielding mechanism in using the all-pixel reading system to form a high-quality image. In this apparatus, for a moving image, a pixel mix signal is read out from a CCD to reproduce motions faithfully. For a still image, to improve the image quality, a shielding period set by the shielding plate is used to read out all the pixels obtained by the CCD during a single exposure in order to form a pixel mix signal using a mixing circuit. A lamp characteristic memory stores table data indicating the characteristic between the lamp voltage of the current lamp and the quantity of outgoing light so that based on this data, a lamp voltage higher than in moving images is supplied to the lamp during the exposure for still-image formation. This configuration compensates for the lack of light quantity caused by a delayed response from the shielding plate to provide an appropriately bright still image. The lack of light quantity can also be compensated for by storing in the memory the characteristic between a diaphragm value and the outgoing light quantity and increasing the numerical aperture of the diaphragm based on the characteristic data.

Inventors: Higuchi; Mitsuru (Omiya, JP), Takeuchi; Shinji (Omiya, JP), Yamanaka; Kazuhiro (Omiya, JP)

Assignee: Fuji Photo Optical Co., Ltd.

International Classification: A61B 1/04 (20060101); A61B 1/06 (20060101); A61B 1/045 (20060101); H04N 5/235 (20060101); H04N 5/225 (20060101); A61B 001/06 ()

Expiration Date: 07/03/2018