SUBASSEMBLY, OBJECTIVE AND LONG THING OPTICAL IMAGE TRANSFER SYSTEM

Abstract

The invention relates to a subassembly (1) for an objective (10), in particular for a long and slim optical image transmission system, for example an endoscope, an objective (10) and an optical image transmission system, as well as methods for manufacturing a subassembly and an objective. The subassembly (1) comprises a prism (2) and an aperture element (3), wherein the prism (2) and the aperture element (3) are fixedly connected to each other, preferably by means of a putty or via direct bonding.

Claims

1.-18. (canceled)

19. A subassembly for an objective, the subassembly comprising a prism and a aperture element, wherein the prism and the aperture element are firmly connected to each other.

20. The subassembly according to claim 19, wherein the prism and the aperture element are firmly connected to each other by means of a putty or via a direct bonding.

21. The subassembly according to claim 19, wherein the prism has a beam entry surface and a beam exit surface and the beam exit surface abuts the aperture element, and wherein the beam entry surface and the beam exit surface enclose an angle γ.

22. The subassembly according to claim 21, wherein y is between 10° and 80°.

23. The subassembly according to claim 19, wherein the prism has two reflection surfaces which are not coated or which are mirror-coated.

24. The subassembly according to claim 19, wherein at least one of the prism and the aperture element are made of glass.

25. An objective, wherein the objective comprises at least one subassembly according to claim 19.

26. The objective according to claim 25, wherein the objective comprises at least on of an entrance lens and at least one imaging lens (12a, 12b, 12c), which are arranged in a common housing (13).

27. The objective according to claim 26, wherein the entrance lens is plano-concave.

28. The objective according to claim 25, wherein a tuning ring is arranged between the entrance lens and the subassembly.

29. An image transmission system, for example endoscope, comprising at least one objective according to claim 25.

30. The image transmission system according to claim 29, wherein the image transmissions system is an endoscope.

31. A method of manufacturing a subassembly according to claim 19, wherein a prism having a beam entry surface and a beam exit surface is fixed to an aperture element in such a way that the beam exit surface abuts the aperture element and covers the aperture opening, wherein the prism is fixedly connected to the aperture element.

32. The method according to claim 31, wherein the prism is adhered by putty to the aperture element.

33. The method according to claim 31, comprising the steps of, providing an aperture wafer, having at least one aperture opening; providing at least one prism base having a beam entrance surface and a beam exit surface; joining the aperture wafer and the prism base body; and cutting the aperture wafer so that a single subassembly is obtained.

34. The method according to claim 33, wherein the aperture wafer is a coated aperture substrate.

35. A method of assembling an objective according to claim 25, comprising: manufacturing a subassembly wherein a prism having a beam entry surface and a beam exit surface is fixed to an aperture element in such a way that the beam exit surface abuts the aperture element and covers the aperture opening, wherein the prism is fixedly connected to the aperture element; and fixing the subassembly in a housing.

36. The method according to claim 35, wherein first an entrance lens is fixed to the housing.

37. The method according to claim 36, wherein a tuning ring is positioned between the entrance lens and the subassembly.

38. The method according to claim 35, wherein first subassembly is fixed to the housing, then an entrance lens is shifted with respect to the subassembly until an optimal position is found and subsequently the entrance lens is fixed to the housing.

39. The method according to claim 35, wherein for bonding from the subassembly into a housing adhesive is brought through an opening in the housing between the subassembly and the housing.

40. The method according to claim 35, wherein the subassembly is pushed into the housing by means of an insertion tool, which has a mounting head with a mounting recess for receiving the aperture element, and a guide body whose outer diameter corresponds to the inner diameter of the housing.

41. The method according to claim 40, wherein a guide pin facing radially away from the guide body of the insertion tool engages a slot provided in the housing when the subassembly has the correct orientation with respect to said housing.

42. An insertion tool for inserting a subassembly into a housing in a method according to claim 35, wherein the insertion tool comprises a mounting head with a mounting recess for receiving the subassembly, and a guide body whose outer diameter corresponds to the inner diameter of the housing.

Description

[0078] Preferred embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawings. In this connection, corresponding elements are provided with matching reference signs.

[0079] It shows

[0080] FIG. 1 a subassembly in lateral sectional view;

[0081] FIG. 2 an objective in perspective sectional view;

[0082] FIG. 3 a schematic representation of a beam path in an objective in lateral sectional view;

[0083] FIG. 4 a schematic representation of objectives in comparison in lateral sectional view;

[0084] FIGS. 5a, 5b subassemblies in perspective view;

[0085] FIGS. 6a-6b schematic illustrations of manufacturing steps;

[0086] FIG. 7 an exploded view of an objective and an insertion tool.

[0087] FIG. 1 shows a subassembly 1 in lateral sectional view. The subassembly 1 comprises a prism 2 and an aperture element 3, which are firmly connected to each other, preferably via a putty or direct bonding.

[0088] The prism 2 has a beam entrance surface 4 and a beam exit surface 5, with the beam exit surface 5 abutting the aperture element 3.

[0089] The beam entrance surface 4 and the beam exit surface 5 enclose an angle γ corresponding to the angle γ between the direction 8 of an incident beam and the direction 9 of an outgoing beam.

[0090] The prism 2 has two reflection surfaces 6, 7. These can be mirror-coated.

[0091] FIG. 2 shows a objective 10 in perspective sectional view. The objective 10 comprises a subassembly 1, a plano-concave entrance lens 11 and three imaging lenses 12a, 12b, 12c, which are arranged in a housing 13.

[0092] The concave surface of the entrance lens 11 is not perpendicular to the longitudinal axis 26 of the housing 13, so that the objective 10 is angled.

[0093] FIG. 3 shows a schematic diagram of a beam path in an objective 10 in a side sectional view.

[0094] The beam 27 passes, for example with a field angle of ±35°, through the plano-concave entrance lens 11. The beam is then passed through the prism 2, whereby a total reflection takes place at the reflection surfaces 6, 7, whereby the beam is deflected. The beam then passes through the aperture 15 of the aperture element 3. Subsequently, the beam passes through three imaging lenses 12a, 12b and 12c.

[0095] FIG. 4 shows a schematic representation of objectives 10 in comparison in lateral sectional view.

[0096] In the objective 10 in the upper illustration, the entrance lens 11 and the subassembly 1 are arranged relative to each other such that a centrally imaged light beam 28 corresponds to an incoming light beam 29 that has an offset 30 from the central axis 31 of the entrance lens 11.

[0097] A tuning ring 14 of length L is arranged in the objective 10 of the upper illustration.

[0098] When this is replaced by a tuning ring 14 of length Lc, as shown in the lower illustration, the distance between the entrance lens 11 and subassembly 1 is altered such that a centrally incoming beam 32 is imaged as a centrally outgoing beam 28.

[0099] FIGS. 5a, 5b show subassemblies 1 in perspective view. The subassembly comprises a prism 2 and an aperture element 3.

[0100] The aperture element 3 has an aperture opening 15.

[0101] An opaque coating 32 is applied to an aperture substrate 17.

[0102] After assembly, the beam exit surface 5 of the prism 2 lies firmly against the aperture element 3 and covers the diaphragm opening 15.

[0103] FIGS. 6a-6b show schematic illustrations of manufacturing steps. First, at least one prism base body 18 is provided according to FIG. 6a.

[0104] Further, an aperture wafer 16 having a plurality of aperture openings 15 is provided.

[0105] Auxiliary lines 33 and markings 34 are provided on the aperture wafer 16.

[0106] The auxiliary lines help to arrange the prism bases 18 on the aperture wafer 16 in such a way that each row of apertures 15 is evenly covered by a prism base 18.

[0107] The prism bases 18 are firmly connected to the diaphragm wafer 16.

[0108] Subsequently, the aperture wafer 16 can be cut parallel to the rod-shaped prism base bodies 18, with the markings 34 serving as orientation.

[0109] Finally, the prism bases are cut together with the aperture wafer 16 to obtain individual subassemblies 1 as shown in FIG. 5b.

[0110] FIG. 7 shows an exploded view of an objective 10 and an insertion tool 19.

[0111] The insertion tool 19 has a mounting head 20 with a mounting recess 21 for receiving the aperture element 3 and a guide body 22, the outer diameter of which corresponds to the inner diameter of the housing 13, so that the insertion tool 19 with the subassembly can be pushed into the housing 13 with a precise fit.

[0112] The insertion tool 19 has a guide pin 24 that points radially away from the guide body 22 of the insertion tool 19. The guide pin 24 can engage a slot 25 provided in the housing 13 when the subassembly 1 has the correct orientation with respect to the housing 13.

[0113] An entrance lens 11 is attached to the housing 13. A tuning ring 14 is positioned between the entrance lens 11 and the subassembly 1.