Pentax

About: Pentax is a based out in . It is known for research contribution in the topics: Lens (optics) & Optical axis. The organization has 826 authors who have published 1178 publications receiving 16271 citations. The organization is also known as: Asahi Kogaku Goshi Kaisha & Asahi Optical Corporation.

Electronic endoscope system

Abstract: An electronic endoscope system includes an image pickup device provided at a distal end of an insertion portion; an image signal processing device; a main light source; an auxiliary light source which emits less amount of light than the light emitted from the main light source; and a light guide member which guides illumination light emitted from one of the main light source and the auxiliary light source to the distal end of the insertion portion to thereby emit the illumination light from the distal end. When the auxiliary light source emits the illumination light instead of the main light source, the image signal processing device sets the gain of the signal output from the image pickup device to a value higher than the gain of the signal when the main light source emits the illumination light, in order to process the image signal.

zoom lens system

Abstract: A zoom lens system includes a negative first lens group and a positive second lens group. The negative first lens group includes a negative lens element and a positive lens element. The positive second lens group includes a positive lens element, a negative lens element, and a positive lens element. At least the object-side positive lens element and the negative lens element are cemented together. The zoom lens system of the present invention satisfies the following conditions: 1.5 1 wherein f2G: the focal length of the positive second lens group; mW: the lateral magnification of the positive second lens group at the short focal length extremity; and mT: the lateral magnification of the positive second lens group at the long focal length extremity; fT: the focal length of the entire zoom lens system at the long focal length extremity; and fW: the focal length of the entire zoom lens system at the short focal length extremity.

Endoscopic tissue collecting instrument

Abstract: An endoscopic tissue collecting instrument is provided, which can collect a large tissue specimen by cutting the tissue positively with a blade of an outer sheath. The blade formed at the distal end of the outer sheath is directed oblique to the circumferential direction of the outer sheath.

Scanning optical system

Abstract: In a scanning optical system including a polygon mirror for dynamically deflecting N laser beams corresponding to N color components and an imaging optical system for converging the laser beams into spot beams on N photosensitive drums respectively, the imaging optical system includes: a front lens group for converging the laser beams principally in a main scanning direction while deflecting the beams to deviate from its optical surface reference axis; and N rear lens groups for converging the laser beams principally in an auxiliary scanning direction respectively. The rear surface of the front lens group and front surfaces of the rear lens groups are formed as two-dimensional polynomial aspherical surfaces. Concretely, the rear surface is formed as a step-like optical surface having N discrete areas of different heights. By the system, the laser beams are separated sufficiently to match the intervals between the photosensitive drums without the need of long optical paths, without deteriorating the scanning performance, and without the need of using mirrors which cause color misregistration and increase costs.

Anti-shake apparatus

Abstract: An anti-shake apparatus for image stabilizing comprises a movable unit and a controller. The movable unit is movable for an anti-shake operation. The controller stops the anti-shake operation after an exposure time and moves the movable unit to a first position after the anti-shake operation. The first position is a position of the movable unit before the exposure time and before the anti-shake operation. The controller moves the movable unit at a decelerated, low rate of speed before finishing its movement to the first position.