The attempt is to improve the light utilization effect by concentrating and irradiating the light on the observation area, and at the same time, to be able to simply wipe the end clean even when dirtied by oil. Optical fiber light guide 7 for illumination is arranged concentrically on the peripheral part of image incident end part 6 in of image guide 6 that has been inserted inside of pipe 2; that light exit end part 7 out is arranged closer to objective lens 3 than the focal point position of objective lens 3. By doing this, after the light that exits and disperses from light exit end part 7 out has advanced along the optical axis facing the linearly in relation to objective lens 3, the light advances by following along the optical axis which diffracts the light in direction passing through the focal point of the object to be observed side of objective lens 3, and it is possible to irradiate nearly all of the light within the range which can be observed by image guide 6, thus improving the light utilization efficiency. Also, because the end aperture part of pipe 2 in which image guide 6 and image light guide 7 is filled up by the objective lens, the end can be easily wiped clean even when dirtied with oil, etc.

An endoscope which provides ample illumination to a surgical field or diagnostic site is disclosed in which a lens train having objective and relay lenses or electronic means for transmitting images therethrough is covered by an outer casing formed from a woven cylindrical sheath composed of a multiplicity of interlaced spirally-extending bundles of optical fibers and an embedding medium for securely interlocking the bundles together. The proximal end of the braided or woven sheath forms a light-receiving post for receiving and transmitting light through the individual fiberoptic cables to their distal ends which terminate around the periphery of the field lens or lenses. Constructing the outer casing of the endoscope from woven fiberoptic bundles provides an adequate quantity of fiberoptic cables to supply ample illumination to the field for endoscopes with one or more field lenses. The construction of the braided sheath also allows the endoscope to be efficiently manufactured. In one alternate embodiment, the outer casing is formed from a plurality of woven radial segments each composed of a multiplicity of interlaced spirally-extending bundles of optical fibers and an embedding medium securely interlocks the radial segments together to form the tubular outer casing. In another alternate embodiment, the outer casing is formed entirely of light-transmitting material and may take the form of interwoven fiberoptic cables which are fused together or an integral, elongate tubular sheath which fits over the lenses or electronic means of the lens train.

A telecentric relay lens system is provided with field lenses in the vicinity of an object and an image, respectively, at both sides of a centrally arranged lens member. In order to produce distortion the field lenses include cemented surfaces, the cemented surface of one of the field lenses being a collective surface, the cemented surface of the other of the field lenses, being oppositely arranged relative to the central lens member, being a diverging surface.

A laparoscope apparatus for use in laparoscopic surgery or the like comprises a cannula with an inner hollow having therein a light guide for introducing light to its tip end for illuminating the object to be observed, and an endoscope which is capable of being pulled into and out from the inner hollow of the cannula. The cannula is airtightly sealed with a transparent member at its tip end, while the endoscope has therein an image pick-up with a wide-angle lens, and the image pick-up is housed in the cannula close to the transparent member.

An endoscope contains no adhesives, epoxies, or other organic materials. The endoscope includes a set of lenses held in position by cylindrical spacers. A pair of windows seal the ends of the endoscope, and prevent the lenses and spacers from falling out. The windows are brazed to the endoscope. Due to the use of brazing, no adhesives are needed to hold the lenses or windows in place. Thus, one can sterilize the endoscope in the high temperature environment of an autoclave, without risking damage to the optical components. The brazing produces a hermetic seal which enables the endoscope to function properly in an environment of high temperature or high pressure, or in chemically abusive environments.