US 6,635,010 B1 · Endoscope objective

Abstract

Endoscope objective having a viewing direction including an angle< >0° relative to the longitudinal axis of the endoscope, comprising a lens system imaging the object field into a single image plane disposed orthogonally on the longitudinal axis, and a prism unit disposed downstream of the distal window of the endoscope along the imaging path, in which the beam is reflected on two boundary surfaces such that the beam will be deflected in the prism unit from the desired viewing direction into the longitudinal axis of the endoscope, wherein a coating is applied on at least one surface on the prism unit, which comprises a thin layer having a refractive index smaller than the refractive index of the material which said prism unit is made of, so that total reflection against the layer occurs. The invention is characterized by the provision that the coating is applied to that surface of the prism unit which faces the glass cover of the endoscope.

Claims31

Dependent claims

Endoscope objective having a viewing angle including an angle of < >0° relative to a longitudinal axis of the endoscope, comprising:

a lens for imaging an object field into a single image plane disposed orthogonally on the longitudinal axis,
a prism having a surface;
said surface including a coating that comprises a thin layer having a refractive index smaller than a refractive index of said prism so that total reflection occurs against the layer;
said surface of said prism is in direct contact with the lens, disposed downstream of a portion of the lens along an imaging path, in which a beam is reflected on two surface areas such that the beam will be deflected in the prism from the viewing angle into the longitudinal axis of the endoscope, and
characterized in that said coating is applied on an entire said surface of said prism facing a distal end of the endoscope.

2 more elements

Endoscope having a longitudinal axis and a viewing angle of < >0° relative to said longitudinal axis of the endoscope, comprising:

an objective lens disposed at a distal end of said endoscope to receive light beams substantially at said viewing angle from an object field;
a prism disposed along said longitudinal axis, having
a first prism surface at an angle relative to the longitudinal axis of the endoscope for receiving and passing the light beams from said objective lens;
a second prism surface for internally reflecting the light beams passed by said first prism surface back onto said first prism surface, so that the light beams are totally internally reflected at said first prism surface along the longitudinal axis of said endoscope;
and
a third prism surface through which the light beams totally internally reflected at said first prism surface emerge from said prism along the longitudinal axis of said endoscope;
and a lens system disposed long said longitudinal axis for receiving the light beams emerging from said prism unit and imaging the object field onto a single image plane disposed orthogonally to said longitudinal axis;
wherein
said first prism surface is entirely provided with a transparent thin coating formed by vapor deposition and including at least one layer having a refractive index smaller than that of a material of said prism, so that the light beams from said objective lens are transmitted by said coating and the light beams internally reflected from said second prism surface to said first prism surface are totally internally reflected at said coating;
and
the objective lens is disposed on and cemented to a distal end portion of said coated first prism surface.

8 more elements

Dependencies are inferred from the claim text.

Endoscope objective

Life of this patent

Endoscope objective

Life of this patent

Abstract

Claims31