Disposable endoscope

• US 5,892,630 A
• Filed: 04/08/1996
• Issued: 04/06/1999
• Est. Priority Date: 02/10/1992
• Status: Expired due to Fees

• Current Assignee: Linvatec Corporation (Jefferies Financial Group, Inc.)
• Original Assignee: Linvatec Corporation (Jefferies Financial Group, Inc.)
• Inventors: Broome, Barry G.
• Primary Examiner(s): NGUYEN, THONG Q
• Application Number:
  US08/629,069
• Time in Patent Office: 1,093 Days
• Field of Search: 359/362-363, 359/423-424, 359/434-435, 359/643-645, 359/656-661, 359/619, 359/831-837, 425/808, 264/2.4, 264/296, 264/322, 264/300, 264/255, 600/129, 600/171, 600/920, 600/121, 600/175, 600/200, 600/160-167
• US Class Current: 359/834
• CPC Class Codes: G02B 23/2423 of the distal end

Abstract

An endoscope includes a disposable probe and a non-disposable focusing ocular. The probe includes a transfer module assembly including one or more relay modules, and an objective element including a distal glass window, a molded plastic prism and three molded plastic lenses. Each of the relay modules contains an entry glass rod, an intermediate glass rod, and an exit rod, each having flat end surfaces and two identical molded plastic doublets. The elements of the ocular are all of glass and include an axially movable focusing doublet and two non-movable doublets. The disposable probe introduces certain aberrations into the image. The non-disposable focusing ocular corrects these aberrations. A single curved surface is formed on the distal glass window of the probe; all other curved optical surfaces of the disposable probe are formed on molded plastic members, thereby reducing the cost of the probe sufficiently to be cost-effective for single patient, disposable use.

Claims

1. A unitary molded prism for an objective group of an elongated endoscope probe for imaging an interior of a cavity, comprising:

an elongated generally cylindrical member having a first distal entry end inclined at a first angle to an optical axis of a disposable endoscope probe, and a plano second proximal exit end orthogonal to the optical axis of the probe, and having first and second planar reflective surfaces formed by inward terminations of first and second recesses in an outer surface of said prism, such that light rays within a field of view of said prism entering said prism at said distal entry end reflect internally within said prism from said first and second reflecting surfaces and exit said prism through said plano second exit end; and

wherein said second reflecting surface is inclined with respect to the optical axis of the probe at an angle different than said first angle between the first distal entry end of the probe and the optical axis.

2. The unitary molded prism of claim 1, wherein the refractive index of the material of said prism and the relative orientation of said entry end and said first and second reflective surfaces are such that reflection of said rays from one of said reflective surfaces takes place by total internal reflection at an interface between the material of said prism and air, said interface being defined by said reflecting surface.

3. The unitary molded prism of claim 1, wherein the inward termination of one of said recesses is coated with a reflective material.

4. The unitary molded plastic prism of claim 1, further comprising an optically opaque baffle disposed in one of said recesses.

5. The unitary molded plastic prism of claim 1, wherein said first and second planar reflective surfaces are disposed such that imaginary longitudinal lines in the planes of and bisecting said first and second planar reflective surfaces intersect the optical axis of said probe, and transverse lines on said first and second planar surfaces orthogonal to the longitudinal lines are parallel to one another.

6. The unitary molded plastic prism of claim 5, wherein a plane including said first reflective surface intersects said optical axis at an angle of approximately 21.5°

and a plane including said second reflective surface intersects said optical axis at an angle of approximately 34°

.

7. The unitary molded plastic prism of claim 1, wherein said prism is molded of type NAS30 copolymer having refractive index 1.564 and dispersion 35.0.

8. The unitary molded prism of claim 1, wherein the angle between the first reflecting surface and the plane of the first distal entry end of the probe is other than half said first angle between the first distal entry end of the probe and the optical axis.

9. A method of manufacture of a unitary optical prism of moldable optical material, said prism consisting of an axially elongated member having one end at an angle to an axis of elongation of said member and one planar end orthogonal to the axis of said member, and having two recesses extending into a body of said member from opposite sides thereof, said recesses each being terminated by planar surfaces, said method comprising the steps of:

providing a mold means, said mold means defining a mold cavity conforming to an outline of said axially elongated member, said mold means comprising first and second slide members, said slide members being controllably inserted into and withdrawn from said mold cavity, said slide members having distal surfaces conforming to desired surface contours of said recesses;

inserting said slide members in said mold cavity;

injecting a quantity of a suitable moldable optical material into said mold cavity;

allowing said material to solidify in conformance to contours of said mold cavity and the distal surfaces of said slide members;

withdrawing said slide members from said mold cavity; and

withdrawing said solidified material from said mold cavity.

10. The method of claim 9, comprising the further step of assembling an opaque baffle in one of the recesses in said solidified material.

11. The method of claim 9, comprising the further step of providing a reflective coating on a planar surface terminating one of said recesses.

12. The method of claim 9, wherein said moldable optical material is type NAS30 acrylic plastic material having an index of refraction of substantially 1.564, and dispersion of 35.0.