EP2614399A1

EP2614399A1 - Laser apparatus for producing a linear intensity distribution in a working plane

Info

Publication number: EP2614399A1
Application number: EP11763877.5A
Authority: EP
Inventors: Aleksei Mikhailov
Original assignee: Limo Patentverwaltung GmbH and Co KG
Current assignee: Limo GmbH
Priority date: 2010-09-09
Filing date: 2011-09-08
Publication date: 2013-07-17
Also published as: US20130182435A1; DE102010044875A1; CN103180774A; JP2013541419A; KR101769653B1; KR20140004070A; US8967826B2; CN103180774B; WO2012032116A1; JP5918768B2

Abstract

The invention relates to an illumination apparatus (1) for producing a linear intensity distribution in a working plane, comprising: at least one group of laser light sources (2, 2a - 2j), which are arranged one above the other in a number N of rows (R1-R6) with in each case a number M of laser light sources (2, 2a - 2j) which are arranged one next to the other, such that they can emit laser light in a first propagation direction; a number of beam-deflection means (4), which are arranged behind the laser light sources (2, 2a - 2j) in the first propagation direction and configured such that they can deflect the laser light emitted by the laser light sources (2, 2a - 2j) into a second propagation direction to the working plane; beam-merging means, which are arranged behind the beam-deflection means (4) in the second propagation direction such that they can merge the individual laser beam bundles of the laser light sources (2, 2a - 2j) into the linear intensity distribution, with adjacent rows (R1-R6) being arranged in a first direction (x-direction) perpendicular to the first and second emission directions and also offset with respect to one another in the first propagation direction (z-direction) such that the laser beam bundles (A-L) of the laser light sources (2, 2a - 2j) can enter the beam-merging means without overlap.

Description

"Laser device for generating a linear

Intensity distribution in a working plane "

The present invention relates to a lighting device for generating a linear intensity distribution in a

Working level.

Definitions: In the propagation direction of the light, the mean propagation direction of the light means, especially if this is not a plane wave or at least partially divergent. By light beam, sub-beam, beam or beam is, unless expressly stated otherwise, not an idealized beam of geometric optics meant, but a real light beam, such as a laser beam with a Gaussian profile, not an infinitesimal small, but an extended beam cross-section having.

In the prior art, long laser lines (e.g., greater than 100 mm) only become separated by a correspondingly large distance

Light source and line generated. Typically, the distance is at least as long as the line is long. In industrial

Applications, this much space is often not available,

especially with line lengths of more than one meter.

The object underlying the present invention is to provide a lighting device of the type mentioned above for producing a linear intensity distribution in a working plane, which is made more compact than the known from the prior art lighting devices and a high

Intensity delivers.

This object is achieved by a

Lighting device solved with the features of claim 1. The dependent claims relate to preferred developments of

Invention.

An illumination device for generating a linear intensity distribution in a working plane, according to claim 1

- At least one group of laser light sources in one

Number N of rows each having a number M of juxtaposed laser light sources are arranged one above the other so that they can emit laser light in a first propagation direction,

a number of beam deflecting means included in the first

Propagation direction behind the laser light sources are arranged and arranged to be that of the

Laser light sources emitted laser light in a second

Can divert the direction of propagation to the working level,

- Beam merger, in the second

Propagation direction so behind the Strahlablenkmitteln

are arranged so that they can merge the individual laser beam of the laser light sources to the linear intensity distribution, wherein adjacent rows in a first direction (x-direction) perpendicular to the first and second radiation on the one hand and in the first propagation direction (z-direction) on the other hand offset from one another are arranged so that the laser beam of the laser light sources without overlap in the

Beam merger can occur. With the help of the lighting device presented here, it is possible in one

Working plane to a linear intensity distribution of great length produce. An advantage of the solution according to the invention is that there are no losses due to overlaps of the

There are laser beam, since these are combined in two independent stages to the linear intensity distribution in the working plane. Each of the laser beam bundles one

Laser light source of the illumination device cooperates in the generation of the linear intensity distribution only with two optical elements, with a beam deflecting means, which the respective laser beam in the direction of the

Deflects work plane, and with the beam merger. By these measures, a linear intensity distribution with high quality can be generated in the working plane. There may also be additional lens means in the beam path of

Lighting device for the waist of the laser beam can be used. However, these take on the actual

Procedure of merging the laser beam to the line-shaped intensity distribution not part. Overall, the lighting device according to the invention can be carried out in an advantageous manner much more compact than the known from the prior art solutions. The laser light sources are

preferably identical - in particular modular - constructed and each have a height H and a width P. Preferably, the laser light sources are implemented as semiconductor laser light sources.

In a preferred embodiment it is provided that

adjacent rows of laser light sources in the first direction (x-direction) are each offset by a constant distance dx to each other. Preferably, adjacent rows in the first direction (x-direction) may each be offset by a distance dx = P / N offset from each other, where P is the width of the

Laser light sources (extension of the laser light sources in the first direction in which the laser light sources are arranged side by side) is. In an advantageous embodiment, provision may be made for the laser beam bundles to be able to enter the beam combining means in a first plane which is at a distance Y = Y1 from the working plane, and in a second plane which differs from the beam joining means

Working plane has a distance Y = Y2, again from the

Beam merge agent can emerge.

In a particularly advantageous embodiment, it is proposed that the distance between the two planes in the y-direction

ΔΥ12 = Υ1-Υ2 is about 2T to 3T, where T is the waist size of the laser beam in the first propagation direction (z-direction). In particular, the spacing of the planes ΔΥ12 can be selected such that the laser beam bundles can be brought together without loss in the second plane to form a linear intensity distribution. The optical path difference remains the same everywhere. This can be achieved, in particular, by, for example, shifting the second row of laser light sources with respect to the first row by H + Δ in the z direction, the third row of laser light sources with respect to the second row by H - Δ, and so on.

In a preferred embodiment of the lighting device it is provided that the beam combining means comprise a number of glass plates, which are arranged so that the

Laser beam at the optical interfaces of the glass plates can be broken so that the laser beam can be merged to the linear intensity distribution. This makes it possible to generate a linear intensity distribution in a particularly high quality in the working plane. In a particularly preferred embodiment it is provided that the glass plates are arranged in pairs crossed with each other. The glass plates can be arranged inclined to the xz plane, for example by an angle of 45 °. It should be emphasized at this point be that the angle between the glass plates and the xz plane does not necessarily have to be 45 °.

The Strahlablenkmittel can in a particularly advantageous

Embodiment, for example, be designed as a mirror means.

During operation, the laser light sources emit laser light, which initially propagates in the first propagation direction (z direction). The laser beam bundles of the laser light sources are individually deflected by means of mirror means by 90 ° in the y direction and thus in the direction of the working plane (x-z plane). It is possible for each of the laser light sources in each case to have a single, directly associated mirror means in order to deflect the laser light emitted by the relevant laser light source. Alternatively, a single common mirror means may be provided for each of the rows of laser light sources.

In a further advantageous embodiment can also

be provided that the illumination device has at least a second group of laser light sources, which is arranged in mirror image to the first group of laser light sources. The linear intensity distribution in the working plane is determined by the

Laser light sources of the two groups generated. The second group of laser light sources, for their part, may in particular be those described in claims 1 to 9 with regard to the first group of laser light sources

have listed features. Other features and advantages of the present invention will become more apparent from the following description

Embodiments with reference to the accompanying

Illustrations. Show in it

Fig. 1 is a perspective view of a

Lighting device, which is carried out according to a first embodiment of the present invention;

Fig. 2a, 2b show two in a Cartesian coordinate system rotated by 90 ° to each other views, the known from the prior art problem of overlapping

illustrate adjacent laser beam;

Fig. 3a is a side view of the lighting device according to

Fig. 1;

Fig. 3b is a plan view of the lighting device according to

Fig. 1 and 3a;

4a, 4b two schematically simplified views that the

Beam patterns illustrate that by means of

Illuminating device according to Figures 1, 3a and 3b can be obtained in two different, in the beam propagation direction spaced apart x-z planes.

Fig. 5a is a side view of a lighting device according to a second embodiment of the

present invention is carried out; Fig. 5b is a plan view of the lighting device according to

Fig. 5a;

Fig. 6a, 6b two schematically simplified views that the

Beam patterns illustrate that by means of

Lighting device according to Fig. 5a, 5b can be obtained in two different, in the beam propagation direction spaced apart x-z planes.

First, reference is made to Fig. 1, which is a

Lighting device 1, which is executed according to a first preferred embodiment of the present invention, shown in perspective view. Further, in Fig. 1 for

Simplification of the further representation of a Cartesian

Coordinate system is shown, which defines the x-direction, the y-direction and the z-direction.

The lighting device 1 has a number of

Laser light sources 2, 2a - 2h, which are constructed in a modular manner and preferably each comprise a laser diode as an emitter. In the present case, the laser light sources 2, 2a-2h have an identical construction and each have a height H and a width P. The

In the present case, laser light sources 2, 2a-2h are arranged side by side in four rows R1, R2, R3, R4 in the x-direction and stacked one above the other in the y-direction. It should already be noted at this point that the number of diagrammatically illustrated rows R1, R2, R3, R4 has been restricted to N = 4 and in each of these four rows M = 5 laser light sources 2, 2a-2h side by side are arranged. It should be emphasized that in the x-direction depending on the means of

Lighting device 1 to be generated line length essential more than five laser light sources 2, 2a - 2h can be arranged side by side.

It becomes clear that adjacent rows R1, R2, R3, R4 of

Laser light sources 2, 2a - 2h are each shifted by a distance dx in the x direction. This displacement dx of adjacent rows R1, R2, R3, R4 in the x-direction is constant for all rows R1, R2, R3, R4, wherein in general form, in particular: dx = P / N. As mentioned above, N is the number of rows R1, R2, R3, R4 (four in the present case) and P is the extension of the laser light sources 2, 2a-2h in the x-direction (width) which are modular in design

Laser light sources 2, 2a - 2h is identical. In the y-direction, the laser light sources 2, 2a-2h are arranged directly above one another so that the "displacement" of adjacent rows R1, R2, R3, R4 of laser light sources 2, 2a-2h in the y-direction of the height H of the

Laser light sources 2, 2a - corresponds to 2h.

During operation, the laser light sources 2, 2a-2h emit laser light, which is initially in a first

Beam propagation direction (z-direction) propagates. The

Laser beam of the laser light sources 2, 2a - 2h are individually by means of beam deflecting means, in particular with the aid of

Mirror means, deflected by 90 ° in a second beam propagation direction (y direction) and thus in the direction of the working plane (x-z plane). There is a possibility that for each of the

Laser light sources 2, 2a - 2h each own Strahlablenkmittel (in particular mirror means) is provided to deflect the laser light emitted by the respective laser light source 2, 2a - 2h laser light by 90 ° in the direction of the working plane. Alternatively, for each of the rows R1, R2, R3, R4 of laser light sources 2, 2a-2h, a respective beam deflection means (in particular mirror means) may be used.

be provided. Thus it can be provided that in Beam propagation direction (z-direction) behind the fourth row R4, a mirror means 4 is arranged, which is that of the

Laser light sources 2a - 2h deflected laser light by 90 ° in the y direction deflects. In Fig. 1, only two individual mirror means 4 are exemplarily indicated in the form of dashed lines in order not to complicate the drawing.

At first glance, it seems that the shift

adjacent rows R1, R2, R3, R4 of laser light sources 2, 2a - 2h in the first beam propagation direction (z direction) should correspond to the vertical displacement H, so that the condition of

Equality of optical path lengths is met. Accordingly, the distance from the beam output window of each laser light source 2, 2a-2h should be to the point of generating the line-shaped

Intensity distribution (Y = Y2) for all laser light sources 2, 2a - 2h be identical and equal to LY + LZ. As will be explained below, this leads at first glance quite obvious

seeming approach to problems that arise with the help of

inventive measures can be avoided.

The main objective with the one described here

Lighting device 1 is to be achieved, is that the brightness of the illuminated line should be as high as possible in the working plane. This means that the laser light emitted by each laser light source 2, 2a-2h in the plane, in the individual

Laser beam to be merged into a line, a beam waist should, as shown schematically in Fig. 2a and 2b. As can be seen in Fig. 2a, this condition is not immediately observed, since there is a zone of overlap of the laser beam A, B, C in the beam return up to this point. This overlapping area, which was illustrated by a horizontal line in FIG. 2a, is in relation to the working plane higher than the point of merging the laser beam A, B, C to a linear intensity distribution. These laser beam bundles A, B, C must have separate lens channels

to be provided.

From the prior art, different methods are known to merge the beam waistlines with maximum dense packing. For this purpose, for example, lens light guide or

Cavity light guide used. Lens light guides are in this

Connection more advantageous and thus more preferable, since their

Manufacturing offers technological advantages. In this case, the distance LW between the lenses when stopping the field within the

Beam waist with the extension W in the x direction with the full

Divergence Θο (in radians) in paraxial approximation LW = W / 0o. In practice it turns out that this period is substantially smaller than the total height of the lighting device 1, which is H ^* N. This means that the lens light guide must consist of several periods, which would make the design of the lighting device considerably more difficult.

This problem is at the presented here

Lighting device 1 thereby avoided that the

Laser beam of the laser light sources 2, 2a - 2h in two

independent steps in the linear

Intensity distribution are transferred. In a first step, the laser beam bundles A, B, C, D are arranged one above the other

Laser light sources 2a, 2f, 2g, 2h in a first plane (x-z plane) at a height Y = Y1 transferred, wherein adjacent laser beam A, B, C, D in the z-direction in pairs have an offset Δ in the z-direction to each other. In the further course, the

Laser beam A, B, C, D in a second plane (xz-plane) at a height Y = Y2, for example, by means of flat, to each other crossed glass plates 5, 6 to a linear

Intensity distribution merged.

In Fig. 1, these glass plates 5, 6 are not shown to the

not to complicate drawing. In Fig. 1, only the steel profile of the laser beam A, B, C, D (and the rest, not provided with a reference numerals

Laser beam) when passing through the glass plates 5, 6 shown. The arrangement of the glass plates 5, 6 in the beam path of the lighting device 1 can be seen in FIG. 3a. The glass plates 5, 6 are arranged so that the laser beam A-L at the optical interfaces of the glass plates 5, 6 can be broken such that the laser beam A-L to the linear

Intensity distribution can be brought together. In the present case, the glass plates 5, 6 form an angle of 45 ° with the x-z plane. It should be emphasized at this point, however, that the angle by which the glass plates 5, 6 are inclined relative to the x-z plane does not necessarily have to be 45 °. The intensity distributions in the first plane at Y = Y1 and in the second plane at Y = Y2 are shown in FIGS. 3a and 3b. In particular, the offset Δ of adjacent laser beam bundles A, B, C, D in the z direction can be seen in FIG. 3 a.

In this case, the distance between the two planes in the y-direction ΔΥ12 = Υ1-Υ2 can advantageously be minimized to a size of about 2T to 3T, where T is the waist size of the laser beam A, B, C, D in the z-direction , If ΔΥ12 is so small that AY12 << LW, the laser beams A, B, C, D can be merged without loss due to overlaps to a linear intensity distribution. The optical path difference remains the same everywhere. This is achieved by, for example, shifting the row R2 with respect to the row R1 by H + Δ in the z-direction, the row R3 with respect to the row R2 by H-Δ, and so on, as can be seen in particular in Fi g .1 and in Fig. 3a.

With the aid of the illumination device 1 presented here, it is possible to produce a linear intensity distribution with high beam quality in the working plane.

Referring to Fig. 5, there is shown a second embodiment of the present invention. While at the

Lighting device 1 according to the first embodiment, a single group of laser light sources 2, 2a - 2h was provided, the lighting device 1 in the one shown here

Embodiment two groups of laser light sources 2, 2a - 2j (in Fig. 5a and 5b left) or 2, 2k-2p (in Fig. 5a and 5b right) on.

The two groups of laser light sources 2, 2a-2j and 2, 2k-2p are mirror images of each other and emit during operation laser light in opposite beam propagation directions in the z-direction. In the present case, the laser light sources 2, 2a-2j or 2, 2k-2p of each of the two groups are arranged one above the other in six rows R1 to R6, wherein in each of the rows a total of five laser light sources 2, 2a-2j, 2, 2k-2p are arranged side by side ,

The laser beam A-L - as already in the first

Embodiment - individually by means of beam deflecting means, in particular by means of mirror means 4, deflected by 90 ° in the y-direction and thus in the direction of the working plane (x-z plane). Which of the beam deflecting means (in the present case mirror means 4) which

Laser beam bundles AL are assigned, resulting from Fig. 3a in conjunction with Fig. 3b. There is a possibility that for each of the Laser light sources 2, 2a - 2j, 2, 2k-2p each have a Strahlablenkmittel (in particular mirror means) is provided to the from the

relevant laser light source 2, 2a - 2h or 2, 2k-2p emitted laser light to deflect 90 °. Alternatively, for each of the rows R1, R2, R3, R4, R5, R6 of laser light sources 2, 2a-2j and 2, 2k-2p, respectively, a beam deflecting means

be provided (in particular mirror means).

The laser beam deflected in this way are in turn in two steps in the manner already described above with the aid of flat glass plates 5, 6 in a linear

Transferred intensity distribution in the working plane. These are arranged crossed in the manner described above.

In the present case, the glass plates 5, 6 in turn enclose an angle of 45 ° with the x-z plane. However, it should again be emphasized at this point that the angle between the glass plates 5, 6 and the x-z plane does not necessarily have to be 45 °. In the first x-z plane at Y = Y1 there are now not two, but three rows of light bundles A-L (see FIG. 6a), which are combined into a line in the second x-z plane at Y = Y2 (FIG. 6). For this purpose, a plurality of flat, mutually crossed glass plates 5, 6 may preferably be arranged in the form of an array.

Once again, the laser light sources 2, 2a-2j, 2, 2k-2p are arranged offset from one another in the x-direction and in the z-direction in the manner described above. Adjacent rows R1 to R6 are offset from one another by the constant distance dx (preferably also here dx = P / N). The offset of adjacent rows R1, R2, R3, R4, R5, R6 of laser light sources 2, 2a-2j or 2, 2k-2p in the first beam propagation direction (z-direction) results directly from FIG. 5a. The main features of the here presented geometric

Arrangements of the laser light sources 2, 2a - 2h or 2, 2a-2j, 2k-2p is that the modular design

Laser light sources 2, 2a - 2h or 2, 2a-2j, 2k-2p

in rows with an offset in the x-direction as well as with an offset in the z-direction in a three-dimensional stack

are summarized without being special

Angle settings of the laser light sources 2, 2a - 2h or 2, 2a-2j, 2k-2p are used.

There are advantageously no losses due to

Overlaps the laser beam as these are in the top

described manner in two stages to the linienformigen

Intensity distribution are brought together.

Each of the laser beam bundles of a laser light source 2, 2a-2h or 2, 2a-2j acts at most with two optical

Elements together, with a Strahlablenkmittel 4, which may be in particular a Strahlablenkspiegel, and each with one of the flat glass plates 5, 6. It can be used in the beam paths additional lens means for the waist. These take part in the procedure of merging the

Laser beam to the linienformigen intensity distribution not part.

Claims

claims:

1. lighting device (1) for generating a line-shaped intensity distribution in a working plane, comprising

- At least one group of laser light sources (2, 2a - 2j) in a number N of rows (R1-R6) each having a number M juxtaposed laser light sources (2, 2a - 2j) are arranged one above the other such that they laser light in can emit a first propagation direction,

- A number of beam deflection means (4) arranged in the first propagation direction behind the laser light sources (2, 2a - 2j) and arranged to receive the laser light emitted from the laser light sources (2, 2a - 2j) in a second propagation direction can distract to the working level,

- Beam merger, in the second

Propagation direction are arranged behind the beam deflecting means (4), that they the individual laser beam of the laser light sources (2, 2a - 2j) to the line-shaped

Can combine intensity distribution,

wherein adjacent rows (R1-R6) in a first direction (x-direction) perpendicular to the first and second emission direction on the one hand and in the first propagation direction (z-direction) on the other hand are offset from one another such that the laser beam bundles (AL) of the laser light sources ( 2, 2a-2j) can enter the beam combining means without overlap.

2. Lighting device (1) according to claim 1, characterized

characterized in that adjacent rows (R1-R6) in the first direction are each offset by a constant distance dx to each other.

3. Lighting device (1) according to claim 2, characterized

characterized in that adjacent rows (R1-R6) in the first direction are each staggered by a distance dx = P / N, where P is the width of the laser light sources (2, 2a-2j).

4. Lighting device (1) according to one of claims 1 to 3, characterized in that the laser beam bundles (AL) in a first plane, which has a distance Y = Y1 from the working plane, can enter the beam merger means and in a second plane, which has a distance Y = Y2 from the working plane, again from the

Beam merge agent can emerge.

5. Lighting device (1) according to claim 4, characterized

characterized in that the distance between the two planes in the y-direction ΔΥ12 = Υ1-Υ2 is about 2T to 3T, where T is the waist size of the laser beam (A-L) in the first

Propagation direction (z-direction) is.

6. Lighting device (1) according to claim 5, characterized

characterized in that the spacing of the planes ΔΥ12 is selected so that the laser beam (A-L) without loss in the second plane to a linear intensity distribution

can be merged.

7. Lighting device (1) according to one of claims 1 to 6, characterized in that the

Beam merge means comprise a number of glass plates (5, 6) which are arranged so that the

Laser beam (AL) at the optical interfaces of the glass plates (5, 6) can be broken so that the Laser beam (AL) to the linear

Intensity distribution can be brought together.

8. Lighting device (1) according to claim 7, characterized

characterized in that the glass plates (5, 6) in pairs

are arranged crossed to each other.

9. Lighting device (1) according to one of claims 1 to 8, characterized in that the beam deflecting means (4) are designed as a mirror means.

10. Lighting device (1) according to one of claims 1 to 9, characterized in that the lighting device (1) at least a second group of laser light sources (2, 2k-2p), the mirror image of the first group of

Laser light sources (2, 2a - 2j) is arranged.