WO2009036926A1

WO2009036926A1 - Optical device

Info

Publication number: WO2009036926A1
Application number: PCT/EP2008/007492
Authority: WO
Inventors: Horst Duschek
Original assignee: Eads Deutschland Gmbh
Priority date: 2007-09-17
Filing date: 2008-09-11
Publication date: 2009-03-26
Also published as: DE102007044301A1

Abstract

Disclosed is an optical device for generating a two-dimensional or three-dimensional light curtain (E; KM) from a point light beam (12), especially a monochromatic coherent light beam (12). Said optical device comprises an axial light entry duct (5) that is associated with an axial direction of incidence of the light beam and has an entry port (4; 35) for the point light beam; a light exit space (7) which extends into the light entry duct (5) on a side of the light entry duct (5) that faces away from the entry port (4) for the light beam and has at least one elongate, slit-type light exit port (8); and an apparatus for splitting, planarly fanning out, and deflecting the point light beam (12) into the elongate, slit-type light exit port (8), said apparatus being placed in the transition zone between the light entry duct (5) and the light exit space (7).

Description

Optical device

The present invention relates to an optical device for fanning a punctiform light beam, in particular a monochromatic coherent light beam.

In particular for bar code readers, optical devices for fanning a punctual laser light beam are known. In the known devices, in this way substantially a triangular plane of light is formed, wherein the spreading has a very small angle. This is unsatisfactory for large-area applications, such as permanently installed bar code readers and cash registers or in applications for alarm systems or light effect devices, since often the parallel use of several known devices is required here.

The present invention is therefore based on the object of avoiding the disadvantages of the known solutions of the prior art and of providing an improved optical device for fanning out a punctiform light beam, in particular a monochromatic coherent light beam.

This object is achieved by an optical device, in particular for use in conjunction with light sources that produce a monochromatic, coherent light in a sharply focused light beam, having the features of claim 1. Advantageous embodiments and further developments of the invention are specified in the dependent claims.

As a result, the disadvantages of the known solutions of the prior art are avoided and provided an improved optical device for fanning a punctual light beam, in particular a monochromatic coherent light beam available. According to the invention, an optical device for generating a 2- or 3-dimensional light curtain from a punctual light beam, in particular a monochromatic coherent light beam, with an axial, an axial direction of the light beam associated light inlet channel having a punctual light beam inlet opening; with a light outlet space which opens on a side remote from the light beam inlet opening of the light inlet channel into the light inlet channel and has at least one elongate, slot-like light outlet opening; and provided with a arranged in the transition region of the light inlet channel and the light outlet space means for splitting, surface fanning and deflecting the punctual light beam in the elongated, slot-like light outlet opening.

Further measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIGS. Show it:

Fig. 1 is a sectional view of a preferred embodiment of the optical device according to the invention;

Fig. 2a is a frontal plan view of a conical mirror body;

2b shows another embodiment of the conical mirror body according to the invention;

3 shows a further embodiment of the optical device according to the invention;

4a, 4b further embodiments of the mirror body according to the invention;

5 shows a third embodiment of the optical device according to the invention; 6 shows a further embodiment of a rotationally symmetrical mirror ring;

7 shows a further embodiment of a conical mirror body;

8a and 8b in frontal view of further embodiments of the mirror body according to the invention;

9 shows an application example for scanning a bar code;

Fig. 10 is an application example for scanning a bar code;

Fig. 11 is an application example for scanning a bar code;

FIG. 12 shows a further example of application of the optical device according to the invention in the form of an alarm system; FIG.

13 shows a further embodiment of an alarm system as application example of the optical device according to the invention;

Fig. 14 shows a further embodiment of the optical device according to the invention.

Fig. 1 shows a sectional view of an advantageous embodiment of the optical device according to the invention. The device consists of a rotationally symmetrical housing 1 with a first housing part 2 and a second housing part 3. The first housing part 2 has an axial inlet opening 4, which opens into an axial light inlet channel 5. The first housing part 2 and the second housing part 3 are axially spaced apart from each other by a translucent centering ring 6, so that a light outlet space 7 is formed between the two housing parts 2, 3 and a radially encircling outlet opening 8. On the side of the second housing part 3 facing the light outlet space 7, a conical mirror body 11 with a cone-shaped axial housing directed towards the inlet opening 4 is arranged on the axis 10, which simultaneously forms the axis of the light inlet channel 5. In the light outlet space 7, an annular lens system 9 is arranged radially inwardly of the centering ring 6. The diameter D of the inlet opening 4 and the axial light inlet channel 5 preferably corresponds to the diameter of the incoming light beam 12 and is of the order of 1 mm to a few mm or cm. The height H of the outlet opening or the width of the light outlet space 7 is also in the order of magnitude of the diameter of the incoming light beam 12. The largest diameter of the conical mirror body 11 again corresponds approximately to the diameter D of the incoming light beam 12. The opening angle of the conical Mirror body is in the present case 90 °. In Fig. 1, reference numeral 13 denotes an elementary beam of the light beam 12 and indicates the optical path in the optical device according to the present invention. The axis 10 of the light inlet channel 5 and the generators of the circumferential light exit opening 8 are perpendicular to each other. A light beam 12 entering through the axial inlet opening 4 into the axial light inlet channel 5 of the housing strikes the conical mirror body 11 and is fanned out into a radially exiting light plane E. The axis 10 of the incoming light beam 12 and the exiting light plane E are perpendicular to each other.

In order to avoid a thermal damage, in particular of the conical mirror body 11 by the monochromatic coherent sharply focused light beam 12, a cooling of the conical mirror body 11 itself or the entire housing interior is advantageously provided with a cooling device, such as a fan, liquid cooling or gas cooling above. Furthermore, it is advantageously provided to widen the diameter D of the incident light beam 12 to such an extent that thermal damage, in particular of the mirror body 11, is avoided, and bundling of the light beam only takes place through the annular lens system 9. FIG. 2 a shows a frontal top view of the conical mirror body 11.

2b shows a further embodiment of the cone-shaped mirror body 11 according to the invention. The mirror body 11 consists of a half-cut cone.

Fig. 3 shows another embodiment of the optical device according to the invention. Components that are similar to those described in connection with FIG. 1, are also provided with the same reference numerals. In the embodiment according to FIG. 3, the axis 10 of the axial light inlet channel 5 and the generatrices of the cone-shaped light outlet space 7 and the direction of the outlet opening 8 intersect at an oblique angle.

The opening angle of the conical mirror body 11 is selected in the present case so that a light beam 12 entering the axial inlet channel 5 is fanned on the conical mirror body 11 into a conical light jacket KM, which leaves the device according to the invention through the radially circumferential outlet openings 8.

FIGS. 4a and 4b show further embodiments of the mirror body 11 according to the invention. As can be seen from the figures, the cone body can also have convex or concave rotationally symmetric mirror surfaces.

Fig. 5 shows a third embodiment of the optical device according to the invention. The advantageous structure of this embodiment corresponds to that described in connection with FIG. The translucent centering ring 6 and the annular lens systems 9 are not shown in FIG. 5 for the sake of simplicity. On the outer peripheral surface of the first housing part 2, a rotationally symmetrical holder 14 is attached. This holder 14 carries on its radially inner side a mirror ring 15 whose mirror surface of the radially encircling outlet opening 8 is exactly opposite. The inclinations of the players gelflächen of the mirror ring 15 are chosen so that the light plane E exiting at the radially circumferential outlet opening deflected and a conically tapered conical light jacket KM is generated.

6 shows a further embodiment of the rotationally symmetrical mirror ring 15, wherein the mirror surfaces are concave.

FIG. 7 shows a further embodiment of a conical mirror body 11. The mirror body 11 is axially movable on the axis 10 via a spring element 17 in an axial bore 16. By means of a mounted on the cylindrical projection of the conical mirror body 11 ferrite ring 18 and a fixed to the inner surfaces of the bore 16 magnetic coil, the axial movement of the conical mirror body 11 can be controlled by a suitable control device.

It is also provided for the mirror body 11 by more than one axis adjustable and / or rotatable form.

In the case of an optical device according to the invention according to the exemplary embodiment of FIG. 5 with a mirror ring 15 according to FIG. 6, the exit angle of the conical light jacket KM can be influenced in this way.

Figures 8a and 8b show in frontal view further embodiments of the mirror body 11 according to the invention. As can be seen from the drawing, the cross-sectional shape of the mirror body 11 need not necessarily be rotationally symmetrical, but may also take other, such as square or triangular shapes. In this way, a certain reflection characteristic of the conical mirror body 11 can be achieved.

The optical device according to the invention is suitable for a variety of applications. FIGS. 9a to 11 show an application example for scanning a bar code. The reference numeral 20 in FIG. 9a designates an optical device according to the invention according to the embodiment of FIG. 5. The device is slightly modified for the present application. On the axis 10 of the device, a cylindrical base 21 is arranged in the emission direction, which carries a detector 22. The optical device is arranged below a glass plate 23, and the distance of the device of the glass plate and the exit angle of the conical light jacket KM is selected so that the conical light jacket KM on the surface of the glass plate 23 on an object lying on the glass plate 23 and reflected the detector 22 is directed.

As can be seen in FIG. 9 b, the conical light jacket KM produces a light ring 24 on the upper surface of the glass plate 23.

As illustrated in FIG. 10, a bar code 25 is moved over this light ring 24. In this way, a scan can be performed by the detector 22.

By a suitable design of the mirror ring 15 of the optical device according to the invention according to FIG. 5, a plurality of concentrically arranged light rings 24 can be produced on the surface of the glass plate 23. For this purpose, the mirror ring 15 may have differently noted, mutually independent mirror surfaces. This embodiment has the advantage that a direction-independent scanning of the bar code can be carried out in a very simple manner.

FIG. 12 shows an alarm system as a further example of application of the optical device according to the invention. An optical device according to the exemplary embodiment of FIG. 1 is arranged on the ceiling of a corridor and radiates a light plane E like a curtain. If the optical device 32 is slightly recessed into the ceiling of the passage, the light plane E hermetically closes the passage. The edges of the light plane E impinging on the walls of the aisle project narrow strips of light L on the walls. If light-sensitive detectors are arranged in strips, any intervention in or through the light plane E can be detected immediately.

Fig. 1 3 shows a further embodiment of an alarm system as an application example of the optical device according to the invention. This embodiment uses an optical device according to FIG. 3. This device 33 is arranged axially above a value object W and emits an expanding conical light jacket KM, in the interior of which the object of value W is located. If the conical light jacket KM hits the surface, e.g. a pedestal, a light ring 34 is projected. If a light-sensitive detector designed in a ring-shaped manner is arranged in this area, then any intervention by the conical light jacket can be detected immediately.

Similarly, e.g. manufacture a cylindrical light jacket with the optical device according to the invention in an embodiment according to FIG. 5. Depending on the diameter of the cylindrical light jacket this can even be accessible on the inside. Due to the fanning out of a punctiform laser beam to form a light jacket of different shape, the energy density in the light jacket wall is very small, depending on the diameter of the light jacket. For applications that are not suitable for a cutting process or similar. however, this is required i.d.R. irrelevant, since sufficiently sensitive sensor elements exist.

With an embodiment of the optical device further periscope or lens-like device can be made, which allow a 360 degree all-round view or an adequate image, without using rotating components. In this case, the beam path shown in Fig. 1 is reversed and it is not necessary that the diameter of the channel 5 is preferably in the order of an incoming laser beam. An image is circularly distorted in such a device. To achieve certain imaging or projection effects, the image may be left in its state or equalized by other optical, electronic or other means. Furthermore, an application of the optical devices for light effect devices according to the invention is conceivable. With one or more optical according to the invention

Devices, in particular according to FIG. 5, it may u.U. be able to generate three-dimensional images over the device.

Figures 14a and b show a further embodiment of the optical device according to the invention. This embodiment is similar in its effect to the embodiment according to FIG. 1, but is intended for optically less demanding fields of application. The optical device is designed as an optical fiber component 31, i. it is made entirely of a translucent material preferably having a high refractive index. The device is rotationally symmetrical and has a violet-shaped cross section. The diameter of the axial entry surface 35 preferably again corresponds to the diameter of the incoming light beam 12. The wall thicknesses of the regions of the optical device which extend radially away from the axis 10 are preferably smaller than the diameter D of the light beam 12. A light beam entering the device 12 is forwarded by total reflection within the device and splitting at the tip P to the radially circumferential outlet opening 8 and leaves the device here.

The device has a first, stem-like region B1, which has a solid cross section and forms the light inlet channel 5 with the light beam inlet opening 35. Furthermore, the device has a second region B2, which opens starting from the first region B1 across the tip or a cleavage point P across flower-like and arcuate to a hollow cross section whose diameter expands starting from the cleavage point P in the longitudinal direction of the optical fiber component. The region B2 has at its end an edge, which forms the elongated, slot-like light outlet opening 8. The region B2 has a wall thickness t which is less than or equal to the diameter D of the punctiform light beam 12. In the present case, it is less than or equal to Half (ie, <= D / 2) of the diameter D of the punctual light beam 12 in the inlet channel or at the entrance surface 35. In the direction from the cleavage point P to the light exit opening 8, the wall thickness t reduced in this example to a wall thickness X ₂ < t.

The invention is not limited in its execution to the above-mentioned preferred embodiment. Rather, a number of variants is conceivable, which makes use of the claimed in the claims solution even in other types.

LIST OF REFERENCE NUMBERS

1 housing

2 first housing part

3 second housing part

4 entrance opening

5 light inlet duct

6 centering ring

7 light outlet space

8 outlet opening

9 lens system

10 axis

11 mirror body

12 light beam

13 elementary ray

14 bracket

15 mirror ring

16 hole

17 spring element

18 ferrite ring

20 optical device

21 sockets

22 detector

23 glass plate

24 light ring

31 optical fiber component

32 optical device

33 optical device

34 light ring

35 entrance area B1 first area

B2 second area

D diameter

E light plane

H height

KM conical Lichtmai

L stripes of light

P peak / split point

W value object t wall thickness t ₂ reduced wall thickness

Claims

claims

1. An optical device for producing a 2- or 3-dimensional light curtain (E; KM) from a punctiform light beam (12), in particular a monochromatic coherent light beam (12), with an axial, an axial beam direction of the light beam associated light inlet channel ( 5) having a punctual light beam entrance opening (4; 35); a light outlet space (7) which opens on a side of the light inlet channel (5) facing away from the light beam inlet opening (4) into the light inlet channel (5) and has at least one elongated slot-like light outlet opening (8); and one in the transition region from the light inlet channel (5) and the

Light outlet chamber (7) arranged means for splitting, surface fan-out and deflecting the punctual light beam (12) in the elongated, slot-like light outlet opening (8).

2. An optical device according to claim 1, characterized in that the means for splitting, deflecting and surface fanning the light beam (12) in the light inlet channel (5) and the light outlet space (7) projecting mirror body (1 1) has ,

3. Optical device according to claim 1, characterized in that the mirror body (11) is movable, in particular axially movable, designed and an actuator for changing the position of the mirror body (11) is provided.

4. Optical device according to one of the aforementioned claims, characterized in that the mirror body (11) facing the light inlet channel (5) and in the through the light inlet channel (5) ver has a projecting light beam (12) projecting point point (P) or sharp edge, which forms an optical light beam splitting element in connection with adjoining this tip (P) or edge areas of the mirror body (11).

5. An optical device according to claim 4, characterized in that the tip (P) has a diameter in the projection direction of the light inlet channel (5) extending light beam (12) considerably smaller than the diameter (D) of the light beam (12) in the light inlet channel (5).

6. An optical device according to claim 2, characterized in that the mirror body (11) of conical or partially conical shape and the conical tip (P) of the light inlet opening (4) faces.

7. An optical device according to claim 3, characterized in that the opening angle of the conical mirror body (11) for directly producing a light curtain in the form of a 2-dimensional planar light surface (E) is 90 °.

8. An optical device according to claim 3, characterized in that the opening angle of the conical mirror body (11) for directly producing a light curtain in the form of a 3-dimensional, conical light jacket surface (KM) is less than 90 ° or greater than 90 °.

9. Optical device according to one of the claims 2 to 5, characterized in that the mirror body (11) is rotationally symmetrical.

10. Optical device according to one of the claims 2 to 5, characterized in that the mirror body (11) has convex or concave mirror surfaces.

1 1. An optical device according to one of the claims 2 to 5, characterized in that the mirror body (11) when viewed in cross section has a plurality of remote, especially polygonal, mirror areas for generating a plurality of independent, in particular concentric light surfaces.

12. An optical device according to one of the aforementioned claims, characterized in that the light beam inlet opening (4) and / or the light channel (5) have a diameter (D) which is less than or equal to

Diameter of the point to be used light beam (12).

13. Optical device according to one of the aforementioned claims, characterized in that the light outlet space (7) is disc-shaped or konusmantelartig.

14. An optical device according to one of the aforementioned claims, characterized in that the at least one elongated slot-like light outlet opening (8) is a circumferential light outlet opening (8), in particular a radially encircling, light outlet opening (8).

15. An optical device according to one of the preceding claims, characterized in that the light outlet opening (8) and / or the light outlet space (7) has a height (H) which is less than or equal to the diameter of the point to be used Light beam (12) is.

16. Optical device according to one of the aforementioned claims, characterized in that the light outlet space (7) has a plurality of elongated, slot-like light outlet opening (8), which are associated with a single mirror body (11).

17. Optical device according to claim 1, characterized in that the light inlet channel (5) with the light beam inlet opening (35), the light outlet space with the elongated, slot-like light outlet opening (8), and the means for splitting ( P), flat

Fanning and deflecting the punctual light beam (12) in the elongated, slit-like light outlet opening (8) in the form of a made of a transparent material, uniform, integrating the aforementioned components, 3-dimensional optical fiber component (31) are formed, which is designed to split the entering into the light beam inlet opening (4) punctual light beam (12) and fan out by total internal reflection in its interior and lead to the light outlet opening (8).

18. An optical device according to claim 17, characterized in that the 3-dimensional light guide component (31) has a first, stem-like region (B1), which has a solid cross section and the light inlet channel (5) with the light beam inlet opening ( 35) forms; and a second region (B2) which, starting from the first region (B1), opens in a flower-like and arcuate manner over a cleavage point (P) to form a hollow cross-section whose diameter widens in the longitudinal direction of the optical-fiber component starting from the cleavage point (P), and (B2) has at its end an edge forming the elongate, slit-like light exit opening (8).

19. An optical device according to claim 17 or 18, characterized in that the second region (B2) has a wall thickness (t) which is less than or equal to the diameter of the punctiform light beam (12), preferably less than or equal to half the diameter of the punctiform one light beam (12) in the light inlet channel (5) and / or the wall thickness in the second region (B2) is reduced in the direction from the point of separation (P) to the light exit opening (8).

20. An optical device according to one of the aforementioned claims, characterized in that in the light outlet space (7) and / or in the region of the light outlet opening (8), a diaphragm for hiding a portion of the at the means for splitting, flat baffles and Deflection of the punctual light beam (12) generated light surface (E; KM) is provided.

Optical device according to one of the preceding claims 1, characterized in that it comprises a light source associated with the light inlet opening (4) for producing a light inlet opening (4; 35) directed in the longitudinal direction of the light inlet channel (5) ) extending punctual light beam (12), in particular a monochromatic coherent light beam (12) possesses.

22. Optical device according to one of the claims 2 to 4, characterized in that a cooling device is provided for cooling the mirror body.

23. An optical device according to claim 1, characterized in that in or at the light exit opening (8) a lens system, in particular an annular lens system (9), is arranged.

24. An optical device according to one of the preceding claims 1, characterized in that based on the in the emission direction on the mirror body (11) generated light surface (E; KM), in particular light plane (E), behind the light-exit opening (8) an optical Lichtflächen-

Deflection system (15) is provided, with the a) the flat light plane (E) is transformable into a 3-dimensional light jacket surface (KM); or b) a 3-dimensional light jacket surface (KM) having a first jacket shape can be transformed into a 3-dimensional light jacket surface (KM) having a second jacket shape.

25. Optical device according to claim 1, characterized in that the longitudinal axis (10) of the axial light inlet channel (5) and a median plane of the disc-shaped light outlet space (7) are perpendicular to one another.

26. An optical device according to claim 1, characterized in that the longitudinal axis (10) of the axial light channel (5) and a center plane of the conical jacket-like light outlet space (7) intersect at an oblique angle.

27. Use of an optical device according to one of claims 1 to 28 as a barcode reader or light effect device.

28. Use of an optical device (32; 33) according to one of claims 1 to 26 as an alarm system.

29. Use according to claim 28, comprising a strip-shaped light-detector system which is arranged at a predetermined distance from the optical device (32; 33) within a strip-shaped or linear (L) cross-sectional or hollow cross-sectional area of one of the optical device (32; ) producible 2- or 3-dimensional light curtain (E; KM) is arranged.

30. Use according to claim 28 or 29, with an optical device (32) which generates a flat light curtain in the form of a closed light plane (E), and the closed light plane (E) is projected into a passage cross-sectional area of a passage of a space, and the passage cross-sectional area is completely closed by the light plane (E), and with a stripe-shaped light-detector system which is along a line (L), meet at the linear edges of the light plane (E) on boundary surfaces of the passage, is arranged within the line-shaped cross section of the edges of the light plane (E), and by means of the light-detector system, the passage of an object through the closed light plane (E) is monitored ,

31. Use according to claim 28 or 29, comprising an optical device (32; 33) which generates a flat light curtain in the form of a self-contained hollow, in particular cone-shaped, light jacket (KM); and the closed light mantle (KM) is projected over an object to be protected (W) and projected onto an object support surface, thus completely closing a space around the object (W) to be protected by means of the light mantle (KM), and with a strip-shaped light-detector system, which is laid along a line on which a line-shaped edge of the light-sheath cross-section meets the object support surface, within the line-shaped edge, and by means of the light-detector system, the passage of an object monitored by the closed light jacket (KM).