EP1344098A1

EP1344098A1 - Projector lens

Info

Publication number: EP1344098A1
Application number: EP01984869A
Authority: EP
Inventors: Günter HERR; Arnd Menschig; Andreas Rose; Hans Theis; Artur Wojt
Original assignee: Euromicron Werkzeuge GmbH
Current assignee: MENSCHIG, ARND
Priority date: 2000-12-20
Filing date: 2001-12-19
Publication date: 2003-09-17
Also published as: DE10065197A1; AU2002233279A1; WO2002050589A1; US20040057028A1; US6980364B2; CA2431930A1

Abstract

The aim of the invention is to improve a projector lens, comprising an optical element (10) for shaping radiation fields emitted from light guides (18), such that the light guide (18) may be optimally coupled to the optical element (10). Said aim is achieved, whereby the optical element (10) is embodied in a monolithic body (12), comprising a radiation field forming region (14) and a connector region (16) for the light guide (18), which form part of the optical element (10) and the connector region (16) comprises a connector surface for a front face of the light guide which approximately matches a diameter of the light guide (18) and is arranged offset from a vicinity (19, 11) of the connector region (16).

Description

β E S C H R E I B U N G

imaging optics

The invention relates to imaging optics comprising an optical element for shaping radiation fields emerging from light guides.

Such imaging optics are known from the prior art, but with these there is always the problem of optimally coupling the light guide to the optical element.

This problem is solved according to the invention in the case of imaging optics of the type described at the outset in that the optical element is formed in a monolithic body which has a radiation-field-forming region and a connection region for the light guide which are part of the optical element, and in that the connection region is a one Diameter of the light guide approximately matched and arranged opposite to an environment of the connection area arranged connection surface for an end face of the light guide.

The advantage of this solution can be seen in the fact that, on the one hand, the optical element is particularly easy to produce by providing the monolithic body and, in addition, despite this simple to produce optical element, the light guide can be fixed in the desired exact position relative to the optical element in a simple manner. With regard to the design of the connection area carrying the connection area, the most varied of possibilities are conceivable. An advantageous solution provides that the connection area forms a protrusion that protrudes from the surroundings of the connection area, to which the light guide can be fixed in a simple manner, particularly when the projection according to the invention has a diameter that approximately corresponds to the diameter of the light guide.

Alternatively, it is conceivable that the connection area is formed as a depression in relation to the surroundings of the connection area, so that centering and thus exact positioning of the light guide relative to the optical element is possible by inserting the end of the respective light guide carrying the end face into such a depression ,

With regard to the design of the optical element, the most varied of possibilities are conceivable.

A preferred solution provides that the optical element is part of a monolithic body extending beyond this, the monolithic body itself having further regions, such as a carrier region.

In this case, the vicinity of the connection region is formed by one side of the monolithic body, for example the carrier region, in particular a rear side thereof. Alternatively, however, it is also conceivable for the monolithic body to be held in a carrier which is not part of the monolithic body, since this simplifies the manufacture of the monolithic body.

In such a case, the vicinity of the connection area is preferably formed by one side of the carrier, preferably a rear side of the carrier.

A particularly advantageous variant of the solution according to the invention provides that the optical element is formed by an approximately cylindrical monolithic body which is approximately cylindrical and comprises both the radiation-shaping region and the connection region, which in turn is held in a carrier.

The cylindrical body itself forms the connection surface, which in turn is then offset from the surroundings, that is to say from the rear of the carrier.

Such deposition of the connection surface can either be achieved in that the monolithic body protrudes beyond the rear like a protrusion or is set back relative to the rear and thus a recess is formed starting from the rear, which extends to the connection surface.

With regard to the formation of the radiation field shaping region, no further details have been given in connection with the exemplary embodiments described so far. Thus, it is preferably provided that the radiation field-forming area has a lens-like curved surface for the radiation field formation.

Another preferred solution provides that the radiation field-forming region has a refractive index gradient for the radiation field formation.

The radiation field-forming region is preferably formed by a cylindrical monolithic body with GRIN optics.

Furthermore, in connection with the previous exemplary embodiments, no further details have been given about the type of arrangement of the optical elements.

An advantageous solution provides that the optical elements are individual optical elements.

These individual optical elements are preferably held by a common carrier.

A particularly favorable solution provides, however, that the optical elements are formed by segment areas of a coherent monolithic body.

The type of radiation field formation has not been defined in connection with the exemplary embodiments described so far. In principle, all types of beam shaping such as focusing, defocusing, etc. are conceivable.

It is particularly expedient if the radiation field-shaping region has boundary surfaces shaped in such a way that rays reflected thereon are essentially not directly reflected back into the light guide and, consequently, the imaging optics work back-free with respect to the light guide.

In the case of a collimating radiation-field-forming area, it is particularly favorable if no exact collimation takes place, since the radiation coming from the light guide is essentially not reflected back into the light guide at interfaces.

The connection between the light guide and the connection area of the connection area can take place in the most varied of ways.

An essentially reflection-free connection is particularly advantageous.

Such a connection can advantageously be realized by gluing or welding by melting.

One way to achieve melting is to provide a heatable material in the area of the areas to be connected, by means of which the material can be heated in the area of the areas to be connected. The heatable material can be applied in the form of a layer.

A particularly advantageous solution provides that a sleeve made of a heatable material is provided in the area of the surfaces to be connected, by means of which the material can be heated in the area of the surfaces to be connected. A cuff has the great advantage that it can run around the area of the surfaces to be connected and thus ensures optimal heating.

Another advantageous solution provides that the light guide is provided with a sleeve made of heatable material in the region of its end face. Providing the light guide with such a sleeve can be realized in a particularly advantageous manner.

The heatable material can be heated, for example, by an electrical current or by an electrical discharge.

It is even more advantageous if the heatable material can be heated by absorption of rays.

Such absorption of rays can also be, for example, a particle beam or an electron beam. An advantageous variant provides that the absorption of rays takes place by absorption of electromagnetic radiation. It is particularly advantageous if the electromagnetic radiation is in the wavelength range of light.

A particularly favorable solution provides that the material can be heated by laser radiation.

The laser radiation can either strike the material from the outside.

However, it is also conceivable to pass the laser radiation through the light guide.

A particularly favorable solution provides that the laser radiation passes through the monolithic body in order to heat up the heatable material.

One possibility of arranging the radiation-absorbing layer is to provide this layer on the end faces to be connected.

When establishing a welded connection, it is particularly expedient to provide a sleeve which can be heated with radiation in the region of the connection to be produced.

Further features and advantages of the invention are the subject of the following description and the drawing of some exemplary embodiments. The drawing shows:

1 shows a longitudinal section through a first embodiment of an imaging optics according to the invention.

Figure 2 is a plan view of the first embodiment in the direction of arrow A in Fig. 1.

3 shows a section similar to FIG. 1 showing reflections at an interface between an optical element of the imaging optics according to the invention;

FIG. 4 shows a representation similar to FIG. 1 of a second exemplary embodiment of an imaging optics according to the invention;

5 shows a representation similar to FIG. 2 of the second exemplary embodiment;

6 shows a representation similar to FIG. 3 of the second exemplary embodiment;

FIG. 7 shows an illustration similar to FIG. 1 of a third exemplary embodiment of an imaging optics according to the invention;

8 shows a representation similar to FIG. 2 of the third exemplary embodiment; FIG. 9 shows a representation similar to FIG. 3 of the third exemplary embodiment;

Fig. 10 is a section along line 10-10 in Fig. 11 by a fourth

Embodiment of an imaging optics according to the invention;

Fig. 11 is a plan view in the direction of arrow B in Fig. 10;

FIG. 12 shows a representation similar to FIG. 1 through the fourth embodiment;

13 shows an illustration similar to FIG. 12 with illustration of laser welds for connecting the light guide and the optical element;

Fig. 14 is a section along line 14-14 in Fig. 15 by a fifth

Exemplary embodiment of an imaging optics according to the invention;

15 is a plan view in the direction of arrow C in FIG. 14;

Fig. 16 is an illustration similar to Fig. 1 of the fifth embodiment and

FIG. 17 shows a variant of the fifth exemplary embodiment in the form of a plan view in the direction of arrow D in FIG. 14. A first exemplary embodiment of an imaging optics according to the invention comprises an optical element, designated as a whole by 10, which, as shown in FIGS. 1 to 3, is formed in a monolithic body 12, which has a radiation field-forming region 14 and a connection region 16 for one as a whole 18 designated light guide and a carrier area 19 lying outside these areas.

The connection area 16 is provided with a connection surface 20 which is adapted in terms of its cross-sectional area to a cross-sectional area of an end face 22 of the light guide 18, the light guide 18 preferably having a core 24 and a jacket 26 and the end face 22 a front end 28 of the core 24 and has an end face 30 of the jacket 26 enclosing this.

The light guide 18 is preferably glued or welded to the connection surface 20 with its end face 22 in order to obtain an essentially reflection-free optical contact between the end face 28 of the core 24 and the connection surface 20.

Furthermore, as shown in FIG. 3, the radiation field shaping region 14 of the monolithic body 12 is designed as a collimating element, which forms a substantially collimated radiation field 42 from a divergent radiation field 40 that spreads from the end face 28 in the optical element 10 a front side 32 opposite the connection surface 20 emerges from the radiation field-forming region 14. In order to achieve the collimating effect, the front side 32 is preferably provided with an area 34 that is curved with respect to a plane 46 that is perpendicular to a beam axis 44, the collimating effect of the radiation field-forming area 14 being determinable, for example, by the curvature.

The curved area 34 forms an interface between the material of the monolithic body 12 and the surrounding medium, so that undesired reflections from rays 48 propagating in the monolithic body 12 can occur there.

The arched region 34 is preferably designed such that the rays 48 that propagate within the monolithic body 12 in the direction of the arched region 34 are reflected such that the reflected rays 50 propagate in such a way that they no longer penetrate into the core 24 through the End face 28 can enter, so that in the monolithic body 12 in the region of the front side 32 a back reflection of the radiation field 40 in the core 24 is substantially avoided.

In addition, it is also advantageous to provide an anti-reflective coating that reduces reflection.

In the first exemplary embodiment, the connection region 16 is preferably designed such that the connection surface 20 is arranged at a distance from a rear side 36 of the carrier region 19 of the monolithic body 12 in such a way that an approximate starting point from the rear side 36 forms a cylindrical, free-standing extension 38, which in turn carries the connection surface 20.

Such a connection surface 20 which is raised in relation to the rear side 36 and whose cross-sectional area corresponds essentially to the diameter of the light guide 18 has the advantage that when fixing, in particular when the end face 22 of the light guide 18 is melted onto the raised and free-standing connection surface 20, then a self-centering effect results if the diameter of the connection surface 20 essentially corresponds to the diameter of the end face 22, and thus a sufficiently precise positioning of the light guide 18 relative to the optical element 10 can be achieved in a simple manner.

In a second exemplary embodiment of an imaging optical system, shown in FIGS. 4 to 6, in contrast to the first exemplary embodiment, the connection region 16 'is designed such that the connection surface 20 is arranged offset with respect to the rear side 36 in the direction of the front side 32 and is thus based on the rear 36 forms a recess 38 'into which the light guide 18 can be inserted with its front region 21 which supports the end face 22 in order to place the end face 22 on the connection surface 20 and to connect it to the latter, for example by gluing or welding or a similar method ,

Furthermore, centering of the front region 21 of the light guide 18 for the connection of the end face 22 thereof to the connection surface 20 takes place through peripheral walls 39 of the recess 38 '. Otherwise, the second exemplary embodiment is designed in the same way as the first exemplary embodiment, so that reference can be made in full to the statements in this regard.

In a third exemplary embodiment of an imaging optical system according to the invention, shown in FIGS. 7 to 9, the optical element 10 is held by a carrier 11, in which the monolithic body 12 is inserted, which has the radiation field shaping region 14 "and the connection region 16", which both have approximately the same diameter and are realized by the monolithic body 12 of the same diameter.

The monolithic body 12 is arranged in the carrier 11 such that the connection region 16 ″ protrudes from a rear side 36 of the carrier 11 and thus, similar to the first exemplary embodiment, forms a free-standing cylindrical projection 38 on which the light guide 18 is welded to its end face 22 is fixable.

In the third exemplary embodiment as well, the radiation field-forming region 14 "of the monolithic body 12 is designed such that it has a substantially collimating effect, the radiation field-forming region 14" being formed by GRIN optics which vary due to a radial and / or axial direction Refractive index has a collimating effect. Such GRIN optics or also called graded index rod optics can be obtained commercially as GRIN lenses or GRIN fibers. In a fourth exemplary embodiment of an imaging optical system, shown in FIGS. 10 to 12, those elements which are identical to the preceding exemplary embodiments are provided with the same reference numerals, so that reference can be made in full to the statements relating to these exemplary embodiments.

In particular, the fourth exemplary embodiment is based on the concept of the first exemplary embodiment, wherein not only a single optical element 10 is provided in the monolithic body 12, but a multiplicity of optical elements 10 ′ is formed in a coherent monolithic body 12 ′, the monolithic body 12 'for each of the optical elements 10'a to 10'c has its own radiation field-forming region 14a-c and its own connection region 16, and the connection region 16a-c and the radiation field-formation region 14a-c are designed in the same way as in the first embodiment.

Furthermore, the light guides 18 are also fixed in the same way as in the first exemplary embodiment on their own connection surfaces 20 of the connection regions 16.

The advantage of this solution is to be seen in particular in the fact that in this solution the self-centering of the end of the light guide 18 which carries the respective end face 22 relative to the connection area 16 is of considerable importance, since a plurality of light guides 18 with a large number of connection areas are thus simple 16 is connectable without obtaining insufficient results due to inadequate centering of the end face 22 relative to the connection surfaces 20. In the fourth exemplary embodiment of the imaging optics, the connection between the light guides 18 and the individual connection surfaces 20 is preferably carried out by welding, preferably melting the material of the end face and / or the light guide 18 close to that in the region 21 of the light guide 18 near the end face 22 is required.

Such a melting of the light guide 18 takes place either as shown in FIG. 13 with the aid of the optical element 10b, in that a divergent laser beam 60 is coupled in via the front side 32b of the optical element 10b and focused on the end face 22 of the light guide 18 and thus the end face 22b heated by the fact that the laser radiation is absorbed by a layer 62 applied to the end face 22b, for example made of SiO ₂ , in order to melt the material in this area.

However, as an alternative or in addition, it is also conceivable, as is also shown in FIG. 13 with reference to the optical element 10a, to couple the diverging laser beam 60 into the radiation field-forming region 14a in such a way that it not only detects the end face 22a of the light guide 28a, but also the connection region 16a and the end of the light guide 18a enclosing the end of the light guide 18a enclosing sleeve 64, which is designed to absorb the laser beam 60 and thus serves in the region of the end face 22a and the connection surface 20a the end of the end face 22a To heat the light guide 18a by means of heat coupling and thus to contribute to the advantageous welding of the end face 22a to the connection surface 20a, so that even with low absorption of the laser beam 60 in the light guide 18, welding with laser radiation 60 coupled in by the optical element 10 is possible.

In a fifth exemplary embodiment, shown in FIGS. 14 to 16, those elements which are identical to those of the preceding exemplary embodiments are provided with the same reference numerals, so that with regard to the description of these elements, reference can be made in full to the explanations regarding the preceding exemplary embodiments ,

The fifth exemplary embodiment of an imaging optical system is based in principle on the second exemplary embodiment, the individual optical elements 10 "being combined to form a single monolithic body 12 'and the connecting regions 16' forming depressions 38 'in accordance with the second exemplary embodiment, into which the light guides 18 with their front ends , 21 adjacent regions 21 can be inserted, positioned and placed on the connecting surface 20.

In a variant of the fifth exemplary embodiment, shown in FIG. 14, in addition to the depressions 38 ', to the side of the same, preferably 70 markings 72 are provided, preferably in an area lying between four depressions 38', which serve, for example, an insertion device as a positioning aid, to when inserting the light guide 18 with their Front side 22a into the recesses 38 ', the light guides 18 can be aligned exactly with the recesses 38' and thus be inserted precisely into them.

The markings 72 are preferably formed by two marking segments 74 and 76 running in mutually perpendicular directions, so that with each marking 72 a point in the respective surface area 70 can be clearly defined.

The markings 72 are preferably arranged such that at least two such markings 72 are assigned to each of the depressions 38 '.

The markings 72 described in connection with the fifth exemplary embodiment can, however, also be provided in the same way for positioning the light guides 18 in the fourth exemplary embodiment according to FIGS. 10 to 13 in intermediate regions between the connecting regions 16 or in the case of monolithic micro-optics without additional structuring of the connecting region.

Claims

EXPECTATIONS

Imaging optics comprising an optical element for forming radiation fields emerging from light guides, characterized in that the optical element (10) is formed in a monolithic body (12) which has a radiation field-forming region (14) and a connection region (16) for the Has light guides (18), which are part of the optical element (10), and that the connection area (16) has a connection area approximately adapted to a diameter of the light guide (18) and offset from an environment (19, 11) of the connection area (16) (20) for an end face (22) of the light guide (18).

Imaging optics according to Claim 1, characterized in that the connection area (16) forms a projection (38) which projects beyond the surroundings (19, 11) of the connection area (16).

Imaging optics according to claim 1, characterized in that the connection area (16 'is designed as a depression (38') relative to the surroundings (19) of the connection area (16 ').

4. Imaging optics according to one of the preceding claims, characterized in that the optical element (10) is part of a monolithic body (12) extending beyond this.

5. imaging optics according to claim 4, characterized in that the vicinity of the connection region (16, 16 ') is formed by one side of the monolithic body (12).

6. imaging optics according to one of claims 1 to 4, characterized in that the monolithic body (12) is held in a separate from this carrier (11).

7. imaging optics according to claim 6, characterized in that the vicinity of the connection region (16) is formed by a side (36) of the carrier (11).

8. imaging optics according to one of claims 6 or 7, characterized in that the optical element (10) by an approximately cylindrical and both the radiation field-forming region (14) and the connection region (16) comprising approximately cylindrical monolithic body (12) is formed is.

9. imaging optics according to one of the preceding claims, characterized in that the radiation field-forming region (14) has a lens-like curved surface (34) for radiation field formation.

10. Imaging optics according to one of the preceding claims, characterized in that the radiation field-forming region (14 ") has a refractive index gradient for radiation field formation.

11. Imaging optics according to one of the preceding claims, characterized in that the optical elements (10) are individual optical elements.

12. Imaging optics according to claim 11, characterized in that the individual optical elements (12) are held by a common carrier (11).

13. Imaging optics according to one of claims 1 to 10, characterized in that the optical elements (10 ') are formed by segment regions of a coherent monolithic body (12').

14. Imaging optics according to one of the preceding claims, characterized in that the radiation field-forming region (14) has interfaces (34) shaped in such a way that rays (48) reflected thereon are essentially not directly reflected back into the light guide (18).

15. imaging optics according to claim 14, characterized in that the radiation field-forming element (14) does not act exactly collimating.

16. Imaging optics according to one of the preceding claims, characterized in that the light guide (18) with the connection surface (20) of the connection region (16) is connected essentially without reflection.

17. Imaging optics according to one of the preceding claims, characterized in that each connection area (16) is assigned a marking (72).

18. imaging optics according to the preamble of claim 1 or according to one of the preceding claims, characterized in that in the region of the surfaces to be connected (22, 20) a heatable material (62, 64) is provided, by means of which the material in the region of the connecting surfaces (22, 20) can be heated.

19. Optical imaging system according to the preamble of claim 1 or according to one of the preceding claims, characterized in that in the area of the surfaces to be connected (22, 20) a sleeve (64) made of a heatable material (62, 64) is provided, by means of which the material can be heated in the area of the surfaces (22, 20) to be connected.

20. Imaging optics according to claim 18 or 19, characterized in that the light guide (18) in the region of its end face (22) is provided with a sleeve (64) made of heatable material.

21. Imaging optics according to one of claims 18 to 20, characterized in that the heatable material (62, 64) can be heated by absorption of rays (60).

22. Optical imaging system according to claim 21, characterized in that the material (62, 64) can be heated by laser radiation.

23. Optical imaging system according to claim 22, characterized in that the material (62, 64) can be heated by laser radiation passing through the monolithic body.