GB2068583A

GB2068583A - Improvements in or Relating to Optical Systems

Info

Publication number: GB2068583A
Application number: GB8041362A
Authority: GB
Original assignee: Richard Wolf GmbH
Current assignee: Richard Wolf GmbH
Priority date: 1979-12-29
Filing date: 1980-12-29
Publication date: 1981-08-12
Also published as: GB2068583B; DE2952731A1; FR2472370B1; FR2472370A1; DE2952731C2

Abstract

A multi-component optical system, particularly for endoscopes, of the kind comprising a plurality of tubular sections connected by joints and each containing lens-like optical transmission elements the length of at least one of which elements is subdivided into parts which are mutually twistable around the axis of this tubular section. The invention consists in that two such tubular sections 3a, 3b abut each other and are pivotable at the mutually confronting extremities around two rigidly overbridged joint spindles 1 and symmetrically with respect to the plane passing through the joint spindles, and an equal-sided roof prism or triangular-section prism 4 is firmly joined to the overbridgment 2, each triangular-section prism 4 having placed in front or after it in the latter case an inverting prism 5, and the two tubular sections abutting each other being mutually pivotable only in the direction of the edge of the prism refraction angle extending transversely to the tubular sections. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Optical Systems The present invention relates to multicomponent optical systems, particularly for endoscopes, of the kind coinprising a plurality of tubular sections connected by joints and each containing lens-like optical transmission elements the length of at least one of which elements is subdivided into parts which are mutually twistable around the axis of this tubular section.

Hereinafter such a system will be referred to as "of the kind described".

In known optical linkage systems of the kind described, image tumbling or inversion occurring during displacement of the elements or links is either indicated by special markings or balanced or cancelled by appropriate manual adjustment of a proximal inverting prism.

It has also already been proposed to compensate for image inversion automatically in optical systems of the kind described, by interconnecting the tube section elements adjacent to each other by means of appropriate gearing and of application of special optical elements in the joints. In these systems, the extremity of each link or tube section has connected to it at right angles a connection to the next tube section, which is constructed in the manner of gearing and which by means of reflectors and inverting prisms automatically eliminates image inversion caused by displacement of two consecutive tube sections.

It is an object of the invention automatically to minimise or eliminate image inversion in optical systems of the kind described, and with considerable simplification of the construction.

Accordingly, the invention consists in a multicomponent optical system, of the kind described wherein two such tubular sections abut each other and are pivotable at the mutually confronting extremities around two rigidly overbridged joint spindles and symmetrically with respect to the plane passing through said joint spindles, and an equal-sided roof prism or triangular-section prism is firmly joined to the overbridgement, each triangular-section prism having placed in front or after it in the latter case an inverting prism, and the two tubular sections abutting each other being mutually pivotable only in the direction of the edge of the prism refraction angle extending transversely to the tubular sections.

Due to this construction, two tubular sections of the system are joined direct to each other via a coupling joint and all the elements or links have their longitudinal axes situated along a straight line in the extended position, the double articulated joints comprising at least two-fold reflectors and extending at right angles to the tubular sections in the case of known optical systems thereby being minimised or eliminated from the start.The image inversion is now eliminated by an equal-sided roof prism or by an isosceles triangular-section prism in each joint, and in the latter case complementarily by means of a fore-mounted or aft-mounted inverting prism The roof prism or triangular-section prism is rigidly connected to the joint spindles of the mutually coupled tubular sections, in such manner that two consecutive sections may be pivoted around their joint spindles symmetrically to a plane passing through the joint spindles. In order that an omnilateral or spatial mobility of the optical linkage system may also be obtained, at least one of the tubular sections is subdivided in known manner, and these parts are mutually twistable around the longitudinal axis of these tubular sections.

In order that the invention may be more clearly understood, reference will now be made to the accompanying drawing, in which two consecutive jointed tubular sections of a multi-component optical system comprising an optional number of such sections are illustrated diagrammatically in two angularly limiting positions with respect to each other.

Referring now to the drawing, the optical system comprises a series of consecutive coupled tubular sections a, b, jointed together and provided with optical elements, the distal section a of which has supplied to it the image of an object which is to be observed at the proximal end in vertically and laterally correct alignment by means of an eyepiece.

This may be accomplished in a particularly uncomplicated manner by coupling to each other two directly consecutive tube sections a, b, by appropriate joints in each case, in such manner that they are symmetrically pivotable around the two joint spindles 1 with respect to the plane passing through the joint spindles. The extremities of these joint spindles 1 are rigidly overbridged by an overbridment 2 which may for example be formed by two plates or a housing of U-shape, the branches of which have the joint spindles 1 secured therein, the web of the U coming into contact with the sections a, b, at one side when the longitudinal axes of the sections form a straight line.The web of the U then forms a limitation or stop for the angle of pivotal displacement of the two tubular sections, i.e. the sections may be pivoted only at one side and symmetrically to the plane passing through the joint spindles 1, with respect to each other. The overbridging housing 2 is advantageously a watertight casing or surrounded by a hermetic sheath, without limiting the mobility.

To obtain the symmetrical pivotal displacement, the mutually confronting extremities of the tubular sections are coupled to each other, for example by intermeshing segments or toothed segments 3 of circular or circular cylindrical form, the joint spindles 1 being the axes of the toothed segments 3 and advantageously intersecting the longitudinal axis of the sections.

A triangular-section prism 4 is rigidly connected to the rigid overbridgment 2 between the confronting extremities of the tubular sections a, b, and an inverting prism 5 is installed in front of or behind this triangular-section prism 4.

Furthermore, at least one of the tubular sections, e.g. the tube section b, is subdivided in its length and the two parts bl and b2 are twistable with respect to each other around their axis by means of a pivot bearing 6. The optical system may be moved in spatially omnilateral manner by virtue of the jointed connection of the sections and the pivot bearing or bearings 6 of one or more sections.

The optical system consequently comprises an integral series of identical components, and each component comprises a triangular-section prism 4 having an inverting prism 5 located in front of or behind the same. Due to these components, every image inversion is cancelled automatically as a result of pivoting two tubular sections with respectto each other and of turning one or more sections around the longitudinal axis of one or more such sections. The pivotal displacement of two sections a, b, with respect to each other is limited in each case to approximately 450 for example on optical grounds, so that the total range of pivotal displacement lies between 450 and 1800.Instead of a right-angles triangularsection prism 4, it is also possible to make use of a triangular section prism having a different angle of refraction, the edge of the angle of refraction extending transversely to the pivoting plane however and being situated opposite to the web of the U-shaped casing or to the base of the triangular-section prism.

The same result as that described above in the embodiment shown can also be obtained by replacing the triangular-section prism 4 and the fore-mounted or aft-mounted reversing prism 5 with a roof prism which occupies the position of the triangular-section prism shown in the embodiment. Any image inversion is then also cancelled automatically under pivotal displacement of the tubular sections and twisting of the latter around the longitudinal axis, so that an image in correct lateral and vertical alignment may also be observed by means of the eyepiece in this case.

Instead of the toothed segments 3, it is possible moreover to incorporate other coupling means, e.g. parallel guides or the like, two obtain the symmetrical pivotal displacement of two mutually adjacent tubular sections at one side with respect to the plane passing through the joint spindles 1.

Claims

1. A multi-component optical system, of the kind described, wherein two such tubular sections abut each other and are pivotable at the mutually confronting extremities around two rigidly overbridged joint spindles and symmetrically with respect to the plane passing through said joint spindles, and an equal-sided roof prism or triangular-section prism is firmly joined to the overbridgment, each triangular-section prism having placed in front or after it in the latter case an inverting prism, and the two tubular sections abutting each other being mutually pivotable only in the direction of the edge of the prism refraction angle extending transversely to the tubular sections.

2. A system as claimed in claim 1, wherein the extremities of two tubular sections are each in coupled engagement via segments of a circle or circular cylinder arranged in mirror image symmetry, the rigidly overbridged pivot spindles of which form the joint spindles of said tubular sections.

3. A system as claimed in claim 1, wherein said pivot spindles intersect the axes of the tubular sections.

4. A system as claimed in claim 1 or 2, wherein parallel guides are incorporated for the angular pivoting symmetrical to the rigid overbridgment of two abutting tubular sections with respect to each other.

5. A system as claimed in any of the preceding claims, wherein the angle of mutual pivotal displacement of the two tubular sections lies between 1800 and approximately 450.

6. A system as claimed in any of the preceding claims, wherein the rigid overbridgment of the joint spindles of two consecutive tubular sections is formed by a rigid U-shaped casing in whose two limbs are secured the extremities of said joint spindles and the web of which forms a limitation for the pivoting angle of the two tubular sections to 1800.

7. An optical system of the kind described, substantially as hereinbefore described with reference to the accompanying drawing.