Abstract: A capsule type endoscope includes an illumination device, an imaging device, and a transparent cover covering the illumination device and the imaging device. The imaging device has an objective optical system and an image sensor. When the objective optical system satisfies Condition (1) described below and a white cylinder with a reflectance of 90%, satisfying Condition (3) described below, is observed, illuminance of the imaging surface of the image sensor satisfies Condition (2) described below, in a state where a longitudinal center axis of a capsule coincides with the center axis of the white cylinder with a reflectance of 90%. ??50° ??(1) T1×0.5?T2 ??(2) D=1.

Abstract: An image forming lens includes a lens element having a flange part that is integral with the lens element. When assembled with an image pickup element to form an image pickup module, an outside perimeter portion of the lens element having a flange part, at a region nearest an image pickup element, is inclined so that outer diameters thereof increase when successively measured at positions nearer to the image pickup element. A frame of the image forming lens according to the invention has an inclined portion on the object side with an outer diameter that becomes smaller when successively measured nearer the object side. Satisfying one or more conditions insures accuracy in assembly and that there will be sufficient room near the object side outside the inclined portion to mount a light source, such as an LED, without having to increase the maximum outer diameter of the image pickup module.

Abstract: An imaging optical system includes a spherical or nearly spherical viewing port, an objective lens that includes an aspheric surface and is formed as a single lens element, and a solid-state image sensor that receives an image formed by the imaging optical system. Specified conditions are satisfied by the imaging optical system and the objective lens so that an in-focus image having low distortion, sufficient contrast, and formed by light rays of restricted angles of incidence is formed even for an object in contact with the viewing port. The specified conditions relate to features of the imaging optical system such as focal length and f-number of the imaging optical system, astigmatism and distortion of the imaging optical system, and pixel pitch of the solid-state image sensor. An endoscope that includes the imaging optical system is also disclosed.

Abstract: An imaging module for endoscopes includes a convex lens and an image sensor in which mutual positions are fixed and a plurality of optical modules that are selectively mountable with respect to the fundamental module so that the observation condition is switched in accordance with an optical module selectively mounted. The imaging module for endoscopes is constructed so that when each of the optical modules is mounted to the fundamental module, an image position and an angle of oblique incidence of light of an observation image on the image sensor are practically unchanged.

Abstract: A capsule endoscope is disclosed that includes a light source, an objective optical system that forms an image of an object that is illuminated by the light source, an image pickup device that receives the image formed by the objective optical system; and a transparent cover that is positioned in front of the objective optical system. Specified conditions are satisfied by the objective optical system so that objects having a shape that conforms with the shape of the transparent cover at the periphery of the field of view, as well as more distant objects on-axis, are within the depth of field of the objective optical system's field of view. The transparent cover itself is purposely kept from being within the depth of field of the objective optical system's field of view.

Abstract: An imaging optical system includes a spherical or nearly spherical viewing port, an objective lens that includes an aspheric surface and is formed as a single lens element, and a solid-state image sensor that receives an image formed by the imaging optical system. Specified conditions are satisfied by the imaging optical system and the objective lens so that an in-focus image having low distortion, sufficient contrast, and formed by light rays of restricted angles of incidence is formed even for an object in contact with the viewing port. The specified conditions relate to features of the imaging optical system such as focal length and f-number of the imaging optical system, astigmatism and distortion of the imaging optical system, and pixel pitch of the solid-state image sensor. An endoscope that includes the imaging optical system is also disclosed.

Abstract: A capsule type endoscope includes an illumination device, an imaging device, and a transparent cover covering the illumination device and the imaging device. The imaging device has an objective optical system and an image sensor. When the objective optical system satisfies Condition (1) described below and a white cylinder with a reflectance of 90%, satisfying Condition (3) described below, is observed, illuminance of the imaging surface of the image sensor satisfies Condition (2) described below, in a state where a longitudinal center axis of a capsule coincides with the center axis of the white cylinder with a reflectance of 90%. ??50°??(1) T1×0.5?T2??(2) D=1.

Abstract: A capsule type endoscope includes an illumination device, an imaging device, and a transparent cover covering the illumination device and the imaging device. The imaging device has an objective optical system and an image sensor. When the objective optical system satisfies Condition (1) described below and a white cylinder with a reflectance of 90%, satisfying Condition (3) described below, is observed, illuminance of the imaging surface of the image sensor satisfies Condition (2) described below, in a state where a longitudinal center axis of a capsule coincides with the center axis of the white cylinder with a reflectance of 90%. ??50°??(1) T1×0.5?T2??(2) D=1.

Abstract: An imaging optical system includes a spherical or nearly spherical viewing port, an objective lens that includes an aspheric surface and is formed as a single lens element, and a solid-state image sensor that receives an image formed by the imaging optical system. Specified conditions are satisfied by the imaging optical system and the objective lens so that an in-focus image having low distortion, sufficient contrast, and formed by light rays of restricted angles of incidence is formed even for an object in contact with the viewing port. The specified conditions relate to features of the imaging optical system such as focal length and f-number of the imaging optical system, astigmatism and distortion of the imaging optical system, and pixel pitch of the solid-state image sensor. An endoscope that includes the imaging optical system is also disclosed.

Abstract: A capsule endoscope is disclosed that includes first and second objective optical systems for forming images of objects viewed in the capsule insertion direction and in the opposite direction on separate areas of one plane where an image pickup surface of an image pickup device is located. The capsule endoscope also includes illuminators for illuminating the objects, and a deflector or deflectors, such as reflecting prisms, for folding light from the objective optical systems to the image pickup surface so that the image pickup surface is parallel to the capsule insertion direction. The objective optical systems are retrofocus optical systems. The illuminators may have emission surfaces centered on the centers of spheres defined by dome-shaped transparent covers aligned along a central axis of the capsule endoscope. The objective optical systems, the deflector or deflectors, and the image pickup device are arranged completely off the central axis of the capsule endoscope.

Abstract: An optical component and an image pick-up device that uses the optical component is disclosed. The optical component is capable of driving an optical lens element that is mounted within a first aperture of the optical component. The optical component includes a frame which includes the first aperture. Flexible supports attach the frame to a fixed structure so that the frame may be moved axially, or moved axially as well as rotated, while being held at a fixed radial position along an axis. The optical component includes a base having a second aperture therein that is substantially aligned with the first aperture. First and second electrodes are positioned on the frame and the base, respectively, and a voltage source is provided for generating an electric field between the electrodes, so as to cause the frame to move axially with respect to the base.

Abstract: A capsule type endoscope includes an illumination device, an imaging device, and a transparent cover covering the illumination device and the imaging device. The imaging device has an objective optical system and an image sensor. When the objective optical system satisfies Condition (1) described below and a white cylinder with a reflectance of 90%, satisfying Condition (3) described below, is observed, illuminance of the imaging surface of the image sensor satisfies Condition (2) described below, in a state where a longitudinal center axis of a capsule coincides with the center axis of the white cylinder with a reflectance of 90%. ??50°??(1) T1×0.5?T2??(2) D=1.

Abstract: A capsule endoscope is disclosed that includes a light source, an objective optical system that forms an image of an object that is illuminated by the light source, an image pickup device that receives the image formed by the objective optical system; and a transparent cover that is positioned in front of the objective optical system. Specified conditions are satisfied by the objective optical system so that objects having a shape that conforms with the shape of the transparent cover at the periphery of the field of view, as well as more distant objects on-axis, are within the depth of field of the objective optical system's field of view. The transparent cover itself is purposely kept from being within the depth of field of the objective optical system's field of view.

Abstract: An imaging optical system includes, in order from the object side, a negative lens, a first deformable mirror, an aperture stop, a positive lens unit, and a second deformable mirror. When a horizontal half angle of view of a ray of light incident on the optical system is represented by &ohgr;, the first and second deformable mirrors satisfying a condition, 50°<2&ohgr;<175°, are used to perform focusing. Whereby, the imaging optical system which allows focusing to be performed, irrespective of its small diameter and size, can be provided.

Abstract: An endoscope system in which a normal observation image and a near observation image are photographed by a solid-state image sensor upon operation of a focus adjustment device for changing a focal length and a working distance satisfies: WDWide>WDtele fwide≧ftele where fwide is a focal length in a normal observation mode, WDwide is a working distance in the normal observation mode, ftele is a focal length in a near observation mode, and WDtele is a working distance in the near observation mode. Whereby, the endoscope system is provided with a wide depth of field so as to allow even a person without considerable skills to easily manipulate the system in the magnifying observation mode, is able to improve accuracy of diagnosis information by enhancing seeming resolution of the magnified information, and is able to improve accuracy of diagnosis by facilitating discussion among a plurality of medical doctors.

Abstract: An imaging optical system includes, in order from the object side, a negative lens, a first deformable mirror, an aperture stop, a positive lens unit, and a second deformable mirror. When a horizontal half angle of view of a ray of light incident on the optical system is represented by &ohgr;, the first and second deformable mirrors satisfying a condition, 50°<2&ohgr;<175°, are used to perform focusing. Whereby, the imaging optical system which allows focusing to be performed, irrespective of its small diameter and size, can be provided.

Abstract: An image pickup optical system for use in a magnifying endoscope or the like in which focus control is effected by moving a solid-state image pickup device. When a simultaneous solid-state image pickup device is used, color shading is suppressed satisfactorily, and flare-preventing measures are taken satisfactorily. Further, the center of the field and the center axis of the endoscope are allowed to coincide with each other at a reduced cost. The optical system is capable of being focused at a plurality of object distances by moving a solid-state image pickup device. The optical system is provided with a field lens by which light rays whose incident angle varies in accordance with focus control are made telecentric.

Abstract: An optical component and an image pick-up device that uses the optical component is disclosed. The optical component is capable of driving an optical lens element that is mounted within a first aperture of the optical component. The optical component includes a frame which includes the first aperture. Flexible supports attach the frame to a fixed structure so that the frame may be moved axially, or moved axially as well as rotated, while being held at a fixed radial position along an axis. The optical component includes a base having a second aperture therein that is substantially aligned with the first aperture. First and second electrodes are positioned on the frame and the base, respectively, and a voltage source is provided for generating an electric field between the electrodes, so as to cause the frame to move axially with respect to the base.

Abstract: An optical system includes a first lens unit, a second lens unit, and a third lens unit. The second lens unit is movable. By moving the second lens unit, astigmatism due to the first lens unit and the second lens unit is corrected and astigmatism due to the second lens unit and the third lens unit is corrected.

Abstract: A TV observation system for endoscopes has an illumination system including a light source for emitting light to illuminate an object and a light transmitting section for transmitting the light from the light source to the distal end of an endoscope.