KR20070099581A - Device for homogenizing light - Google Patents

Abstract

The invention relates to a device for homogenizing light, comprising at least two cylindrical lens arrays (17, 20), which are placed one behind the other in a direction of diffusion (Z) of the light (25) to be homogenized and which each have convex and concave cylindrical lenses (18, 19, 21, 22) arranged next to one another in an alternating manner, the cylinder axes of these cylindrical lenses being aligned parallel to one another. In direction (X), in which the cylindrical lenses (18, 19, 21, 22) are arranged next to one another, the concave cylindrical lenses (19) of the first cylindrical lens array (17) have a shaping, in particular, an extension or curvature different from that of the concave cylindrical lenses (22) of the second cylindrical lens arrays (20).

Description

Light homogenizer {DEVICE FOR HOMOGENIZING LIGHT}

The present invention provides a first cylinder lens array, in which light to be homogenized passes through the first cylinder lens array, the first cylinder lens array having convex and concave cylinder lenses having cylinder axes parallel to each other, wherein the cylinder lenses alternate. A first cylinder lens array disposed side by side with each other; And a second cylinder lens array, wherein light passing through the first cylinder lens array passes through the second cylinder lens array, the second cylinder lens array having convex and concave cylinder lenses having cylinder axes parallel to each other, The cylinder lenses comprise a second cylinder lens array, arranged alternately next to each other, the cylinder axis of the cylinder lens of the second cylinder lens array aligned parallel to the cylinder axis of the cylinder lens of the first cylinder lens array. And a light equalizing device. The invention also relates to an apparatus according to the preamble of claim 16.

The apparatus includes a cylinder lens array with concave cylinder lenses that are much smaller than adjacent convex cylinder lenses. For example, concave cylinder lenses may be only grooves or approximately flat areas in the space between two convex cylinder lenses. Devices in this manner are known. Such devices are used, for example, to homogenize relatively non-uniform light from excimer laser or laser diode bars. 1 schematically shows the principle of operation of such a homogenizing device. In the case of the device shown, a first cylinder lens array 1 is arranged on the first substrate 2 and a second cylinder lens array 3 on the second substrate 4. The substrates 2 and 4 are spaced apart from each other. The non-uniform light 5 striking the device is uniformized by the device by the light being distributed evenly over the angular range of the light field 6 exiting the device by the individual cylinder lenses of the cylinder lens arrays 1, 3. . By means of a field lens arranged behind the second substrate 4, a uniform angular distribution in the emission light field 6 can be converted into a corresponding uniform position distribution in the working plane.

In the case of the device of the above-described manner, the focal width of the convex cylinder lens of the second cylinder lens array 3 generally corresponds approximately to the distance between the first and second cylinder lens arrays. Due to this, the convex cylinder lenses of the second cylinder lens array image a plane in the working plane perpendicular to the direction of propagation of the nonuniform light 5 incident on the region of the first cylinder lens array.

2 shows how the incident nonuniform light 5 is convex and concave cylinder lenses 7, 8 of the first cylinder lens array 1, and convex and concave cylinder lenses 9 of the second cylinder lens array 2. , 10) is shown in detail. In FIG. 2, in particular, partial beams 11, 12 extending in the left and right image regions are shown. Said partial beams 11, 12 of light 5 to be homogenized pass through two concave cylinder lenses 8 of the first cylinder lens array. The partial beams 11, 12 are largely deflected by the concave cylinder lens 8 into the convex cylinder lens 9 of the second cylinder lens array 2. By means of the convex cylinder lens 9 the partial beams 11, 12 are deflected at an angle reaching the outer lateral area of the illuminated area in the working plane upon overlapping the lines of magnetic force.

The situation is shown schematically in FIG. 3. In FIG. 3, the intensity in the working plane is shown in position coordinates or angular coordinates. The light distribution shown in FIG. 3 has an intermediate uniform area 13 and two end side overshoots 14. The overshoot is caused by the partial beams 11, 12 or another corresponding partial beam which has passed through the concave cylinder lens 8 of the first cylinder lens array 1. In this connection, the concave cylinder lens 8 of the first cylinder lens array 1 has a very small radius and thus a very small focal width. Due to this, the virtual focal point of the concave cylinder lens 8 lies in the plane of the first cylinder lens array 1 and is imaged in the working plane by the convex cylinder lens 9 of the second cylinder lens array 2.

The overshoot 14, which is typical in the prior art, shown in FIG. 3, is undesirable for all applications.

It is an object of the present invention to provide an apparatus of the aforementioned manner which can form a uniform light distribution in the working plane.

This object is achieved by an apparatus of the above-described manner with the features of claims 1 or 16 according to the invention. The dependent claims present preferred embodiments of the invention.

According to claim 1, the concave cylinder lenses of the first cylinder lens array in the direction in which the cylinder lenses are arranged next to each other have a different shape from the concave cylinder lenses of the second cylinder lens array in the direction in which the cylinder lenses are arranged next to each other. For example, the overshoot shown in FIG. 3 can be prevented by intentional change in the length and / or curvature of the concave cylinder lens of the first and / or second cylinder lens array.

For example, the concave cylinder lens of the second cylinder lens array is larger than the concave cylinder lens of the first cylinder lens array in the direction in which the cylinder lenses are arranged next to each other. Preferably it is much larger. For example, the concave cylinder lens of the second cylinder lens array is at least approximately twice as large as the concave cylinder lens of the first cylinder lens array in this direction. The enlargement of the concave cylinder lens of the second cylinder lens array prevents, at least in part, from hitting the convex cylinder lens of the second cylinder lens array with the partial beam passing through the concave cylinder lens of the first cylinder lens array. Thus, the partial beam passing through the concave cylinder lens of the first cylinder lens array is no longer deflected or imaged by the concave cylinder lens of the second cylinder lens array into the lateral region of the light field in the working plane. This eliminates overshoot. Thus, the uniform region 13 shown in FIG. 3 is enlarged. In particular, due to the fact that the partial beam passing through the concave cylinder lens of the first cylinder lens array passes through the concave cylinder lens of the second cylinder lens array, the partial beam is distributed over the entire width of the uniform light field in the working plane. do. For this reason, the efficiency (light amount or total light amount in a uniform area) of an apparatus becomes large.

Furthermore, there is a possibility that the convex cylinder lens of the first cylinder lens array can be larger, in particular several times larger than the concave cylinder lens of the first cylinder lens array, in the direction in which the cylinder lenses are arranged next to each other. In particular, the concave cylinder lens may form a groove or an almost flat area between the concave cylinder lenses of the first cylinder lens array.

As in the prior art, in the present invention, there is a possibility that the focal width of the convex cylinder lens of the second cylinder lens array may be about the size of the gap between the first cylinder lens array and the second cylinder lens array. As a result, the plane of the first cylinder lens array is imaged within the working plane by the convex cylinder lens of the second cylinder lens array.

According to another preferred embodiment of the present invention, the focal width of the concave cylinder lens of the first cylinder lens array is greater than the focal width of the convex cylinder lens of the second cylinder lens array. Because of this, the virtual focus of the concave cylinder lens of the first cylinder lens array is relatively far from the focal plane of the second cylinder lens array, so that the focus is sharply imaged in the working plane by the convex cylinder lens of the second cylinder lens array. It doesn't work. This allows the partial beam (previously passing through the concave cylinder lens of the first cylinder lens array) to pass through the convex cylinder lens of the second cylinder lens array even if the concave cylinder lens of the second cylinder lens array is relatively small. In either case, no overshoot appears in the lateral region of the light distribution in the working plane.

The concave cylinder lens of the first cylinder lens array in the direction in which the cylinder lenses are arranged next to each other has a length substantially equal to the convex cylinder lens of the first cylinder lens array in the direction in which the cylinder lenses are arranged next to each other. In such a device, the focus of the concave cylinder lens may be far from the plane of the first cylinder lens array.

The apparatus includes a substrate, and a first cylinder lens array and a second cylinder lens array may be disposed on opposite sides of the substrate. The substrate has a suitable thickness such that the first cylinder lens array can be spaced apart from the second cylinder lens array at intervals of the focal width of the convex cylinder lenses of the second cylinder lens array.

Alternatively, the apparatus may comprise a first substrate and a second substrate different from the first substrate, in particular spaced from the first substrate, wherein the first cylinder lens array is on the first substrate and the second cylinder lens. The array may be disposed on the second substrate. For such an apparatus, the spacing between the substrates can be adjusted so that the spacing between the first cylinder lens array and the second cylinder lens array corresponds to the focal width of the convex cylinder lens of the second cylinder lens array.

In such a device the device also comprises a third cylinder lens array, which is arranged on the side of the first substrate opposite to the first cylinder lens array and alternately arranged next to each other, parallel to each other. A convex and concave cylinder lens having a cylinder axis, wherein the cylinder axis of the cylinder lens of the first cylinder lens array is disposed perpendicular to the cylinder axis of the cylinder lens of the third cylinder lens array.

As an alternative or in addition, the apparatus also includes a fourth cylinder lens array, which is arranged on the side of the second substrate facing the second cylinder lens array and alternately arranged next to each other, A convex and concave cylinder lens having cylinder axes parallel to each other, wherein the cylinder axis of the cylinder lens of the second cylinder lens array is disposed perpendicular to the cylinder axis of the cylinder lens of the fourth cylinder lens array. With the third and optionally fourth cylinder lens arrays, the homogenization of the light to be homogenized can be made in a direction perpendicular to the direction in which the first and second cylinder lens arrays contribute to homogenization. To this end, the third and fourth cylinder lens arrays can be formed correspondingly to the first and second cylinder lens arrays, particularly with regard to the width of the concave cylinder lenses of the third and fourth cylinder lens arrays. Further, the spacing between the third cylinder lens array and the fourth cylinder lens array may correspond to the focal width of the convex cylinder lens of the third cylinder lens array.

According to claim 16, the concave cylinder mirrors of the first cylinder mirror array in a direction in which the cylinder mirrors are arranged next to each other are different from the concave cylinder mirrors of the second cylinder mirror array, in particular in a direction in which the cylinder mirrors are arranged next to each other. It may have a length and / or other curvature. By applying the properties of the cylinder lens array according to claims 1 to 15 to the cylinder mirror array, the same advantages are obtained.

In particular, the device according to claim 16 can be improved by the corresponding features described in claims 2 to 15 for a cylinder lens array. In particular, the focus of the concave cylinder mirror of the first cylinder mirror array may be far from the plane of the first cylinder mirror array. Also, the concave cylinder mirror of the second cylinder mirror array may be larger than the concave cylinder mirror of the first cylinder mirror array. In particular it may be significantly larger. Further, the spacing between the first cylinder mirror array and the second cylinder mirror array corresponds approximately to the focal width of the concave cylinder mirror of the second cylinder mirror array. Also, a third and / or fourth cylinder mirror array may be provided, the cylinder mirror arrays comprising cylinder mirrors having a cylinder axis aligned perpendicular to the cylinder axis of the cylinder mirrors of the first and second cylinder mirror arrays. do.

Other features and advantages of the invention are set forth in the following description of the preferred embodiments with reference to the accompanying drawings.

1 is a schematic view showing the operating principle of the light equalization device.

2 is a schematic side view of a homogenizing device according to the prior art;

3 shows a schematic view of the light distribution in the working plane, formed by the homogenizing device according to FIG. 2.

4 is a schematic partial view of a first embodiment of the device according to the invention.

5 is a schematic partial view of a second embodiment of the device according to the invention.

4 and 5 show a Cartesian coordinate system for clarity.

The first embodiment of the device according to the invention, shown in FIG. 4, comprises a first substrate 15 and a second substrate 16. The first substrate 15 has the first cylinder lens array 17 at its entrance face, while the exit face is formed in a plane. As an alternative, it is also possible for the exit surface to have, for example, a cylinder lens array arranged crosswise with respect to the first cylinder lens array 17. The first cylinder lens array 17 has a convex cylinder lens 18 and a concave cylinder lens 19, which are alternately arranged next to each other. In the embodiment shown in FIG. 4, only two concave cylinder lenses 19 and one convex cylinder lenses 18 are shown. However, a plurality of convex and concave cylinder lenses 18 and 19 may be arranged next to each other in the X direction. The concave cylinder lens 19 extends much shorter than the convex cylinder lens 18 in the X direction, ie the direction in which the cylinder lenses 18, 19 are arranged next to each other.

The second substrate 16 has a second cylinder lens array 20 with a convex cylinder lens 21 and a concave cylinder lens 22 on its incidence surface, ie on its side towards the first substrate 15. The convex and concave cylinder lenses 21 and 22 are alternately arranged side by side in the X direction, and here again a plurality of convex and concave cylinder lenses 21 and 22 may be provided on the entrance face of the substrate 16. 4 also shows the cylinder axis of the cylinder lenses 18, 19 of the first cylinder lens array 17 and the cylinder axis of the convex and concave cylinder lenses 21, 22 of the second cylinder lens array 20. Direction, ie in a direction perpendicular to the X direction in which the cylinder lenses are arranged next to each other. The exit surface of the second substrate 16 is formed in a plane. As an alternative, the exit surface of the second substrate 16 is a different cylinder, in which the cylinder axis of the cylinder lens can be aligned perpendicularly to the cylinder axis of the cylinder lenses 21, 22 of the second cylinder lens array 20. It may have a lens array.

As shown in FIG. 4, the concave cylinder lens 22 of the second cylinder lens array 20 is arranged in the X direction, that is, in the direction in which the cylinder lenses 18, 19, 21, 22 are arranged next to each other. It is much larger than the concave cylinder lens 19 of the cylinder lens array 17. In particular, in this embodiment the concave cylinder lens 22 of the second cylinder lens array 20 is about two times wider than the concave cylinder lens 19 of the first cylinder lens array 17.

4 also shows the partial beams 23, 24 of the light 25 to be homogenized, which has passed through the concave cylinder lens 19 of the first cylinder lens array 17. Unlike the partial beams 11, 12 according to the prior art (see FIG. 2), the partial beams 23, 24 do not pass through the concave cylinder lens 21 of the second cylinder lens array 20 or have a slight amount. Only pass through and through the enlarged concave cylinder lens 22 of the second cylinder lens array. This allows the partial beams 23, 24 to be distributed by the concave cylinder lens 22 of the second cylinder lens array 20 so that they are distributed over a wide range in the operating plane, in particular over the entire width of the uniform light field. Biased. This avoids the side overshoot 14 according to the prior art, shown in FIG. 3.

A second embodiment of the device according to the invention, shown in FIG. 5, also has a first substrate 26 and a second substrate 27. The first substrate 26 has a first cylinder lens array 28 having a convex cylinder lens 29 and a concave cylinder lens 30 on its incidence surface. The second substrate 27 comprises a second cylinder lens array 31 having a convex cylinder lens 32 and a concave cylinder lens 33 on its incidence surface, ie on the side facing the first substrate 26. In the case of the two substrates 26, 27, not only the illustrated number of cylinder lenses 29, 30, 32, 33 are arranged but also the plurality of cylinder lenses 29, 30, 32, 33 are alternately next to each other. Can be arranged.

In contrast to the embodiment according to FIG. 4, in the embodiment according to FIG. 5 the concave cylinder lens 30 of the first cylinder lens array 28 is in the X direction, ie the cylinder lenses 29, 30 alternately with each other. It has the same width or the same length as the convex cylinder lens 29 of the 1st cylinder lens array 28 in the direction arrange | positioned side by side. Alternatively, the concave cylinder lens 33 of the second cylinder lens array 31 is much smaller than the convex cylinder lens 32 of the second cylinder lens array 31.

Due to the same width of the concave and convex cylinder lenses 30, 29 of the first cylinder lens array 28, the focal width f _1k of the concave cylinder lens 30 of the first cylinder lens array 28 is relatively large. . That is, it is about twice the height or length of the convex cylinder lens 29 in the propagation direction Z of light to be uniformized. In FIG. 5, for clarity, the focal width f _2v of the concave cylinder lens 32 of the second cylinder lens array 31 is shown. As shown in FIG. 5, the focal width f _2v of the convex cylinder lens 32 corresponds approximately to the distance between the first cylinder lens array 28 and the second cylinder lens array 31. Due to the relatively large focal width f _1k of the concave cylinder lens 30 of the first cylinder lens array 28, the virtual focal point 34 of the concave cylinder lens 30 schematically shown in FIG. It is not imaged in the working plane by the convex cylinder lens 32 of the lens array 31. This is represented by the partial beams 35, 36, 37 illustratively shown in FIG. 5.

In the embodiment according to FIG. 4 and in the propagation direction of light to be homogenized in the embodiment according to FIG. 5, the vertex lines of the convex cylinder lenses 18, 29 of the first cylinder lens array 17, 18 are the second cylinder lens array. It is aligned with the vertex line of the convex cylinder lenses 21 and 32 of (20, 31). Further, the vertex lines of the concave cylinder lenses 19 and 30 of the first cylinder lens arrays 17 and 28 are aligned with the vertex lines of the concave cylinder lenses 22 and 33 of the second cylinder lens arrays 20 and 31. do.

Claims (16)

As a first cylinder lens array 17, 28, light 25 to be homogenized can pass through the first cylinder lens array 17, 28, the first cylinder lens array 17, 28 being parallel to each other. A first cylinder lens array (17, 28) having convex and concave cylinder lenses (18, 19, 29, 30) having one cylinder axis, the cylinder lenses being alternately arranged next to each other; And As the second cylinder lens array (20, 31), light passing through the first cylinder lens array (17, 28) can pass through the second cylinder lens array (20, 31), the second cylinder lens The arrays 20, 31 have convex and concave cylinder lenses 21, 22, 32, 33 with cylinder axes parallel to one another, the cylinder lenses alternately arranged next to each other, second cylinder lens array 20, 31. And the cylinder axis of the cylinder lenses 21, 22, 32, 33 of the second cylinder lens array 20, 31 is the cylinder lens 18 of the first cylinder lens array 17, 28. In the light equalizing device, parallel to the cylinder axis of 19, 29, 39, The concave cylinder lenses 19, 30 of the first cylinder lens array 17, 28 in the direction X in which the cylinder lenses 18, 19, 29, and 30 are arranged next to each other, the cylinder lenses (21, 22, 32, 33) has a shape different from the concave cylinder lenses (22, 33) of the second cylinder lens array (20, 31) in the direction (X) arranged side by side, Light homogenizer. The concave cylinder lens (19, 30) of the first cylinder lens array (17, 28) according to claim 1, wherein the cylinder lenses (18, 19, 29, 39) are arranged in parallel with each other (X). Is different in length from the concave cylinder lenses 22 and 33 of the second cylinder lens array 20 and 31 in the direction X in which the cylinder lenses 21, 22, 32 and 33 are arranged next to each other. Or curvature. The vertex line of the concave cylinder lenses (19, 30) of the first cylinder lens array (17, 28) in the propagation direction of the light to be homogenized is the second Light alignment device, characterized in that aligned with respect to the vertex line of the concave cylinder lens (22, 33) of the cylinder lens array (20, 31). The cylinder lenses 18, 19, 21, 22, 29, 30 of claim 1, wherein the cylinder lenses 18, 19, 21, 22, 29, 30 of the first and / or second cylinder lens arrays 17. , Characterized in that the cylinder axes of 32, 33 are vertically aligned with respect to the direction X in which the cylinder lenses 18, 19, 21, 22, 29, 30, 32, 33 are arranged next to each other, Light homogenizer. The concave cylinder lenses 22 of the second cylinder lens array 20, wherein the cylinder lenses 18, 19, 21, 22 are parallel to each other. Light homogenizing device, characterized in that in the direction of placement (X) is larger than the concave cylinder lens (19) of the first cylinder lens array (17), preferably much larger. 6. The convex cylinder lenses 18 according to claim 1, wherein the convex cylinder lenses 18 of the first cylinder lens array 17 have the cylinder lenses 18, 19, 21, 22 side by side. Light homogenizing device, characterized in that in the direction (X) arranged, larger, in particular several times larger than said concave cylinder lens (19) of said first cylinder lens array (17). The focal width (f _2v ) of the convex cylinder lenses (21, 32) of the second cylinder lens array (20, 31) is defined by the first cylinder lens array (8). 17, 28, and the size of the interval between the second cylinder lens array (20, 31), light equalizing device. The focal width f _1k of the concave cylinder lens 30 of the first cylinder lens array 28 is set in the propagation direction of the light 25 to be equalized. Z) longer than the length of the convex cylinder lens (29) of the first cylinder lens array (28). 9. The first cylinder lens according to claim 8, wherein the focal width f _1k of the concave cylinder lens 30 of the first cylinder lens array 28 is in the propagation direction Z of the light 25 to be equalized. Light equalizing device, characterized in that at least twice the length of the convex cylinder lens (29) of the array (28). The concave cylinder lens 30 of the first cylinder lens array 28 in the direction in which the cylinder lenses 29 and 30 are arranged next to each other, the cylinder lenses (10). And 29, 30 having a length substantially equal to that of the convex cylinder lens (29) of the first cylinder lens array (28) in the direction (X) arranged next to each other. The focal width (f _1k ) of the concave cylinder lens (30) of the first cylinder lens array (28) is equal to that of the second cylinder lens array (31). A light homogenizing device, characterized in that it is larger than the focal width of the concave cylinder lens (33). 12. The device of any one of the preceding claims, wherein the device comprises a substrate, and wherein the first cylinder lens array and the second cylinder lens array are disposed on opposite sides of the substrate. , Light equalization device. The device according to one of the preceding claims, wherein the device is different from the first substrate (15, 26) and in particular from the first substrate (15, 26). (16, 27), wherein the first cylinder lens array (17, 28) is on the first substrate (15, 26) and the second cylinder lens array (20, 31) is on the second substrate (16, 27). Light homogenizing apparatus, characterized in that disposed in. 14. The device of claim 13, wherein the device comprises a third cylinder lens array, the third cylinder lens array being on the side of the first substrate (15, 26) facing the first cylinder lens array (17, 28). The convex and concave cylinder lenses having cylinder axes parallel to each other, arranged alternately next to each other, and of the cylinder lenses 18, 19, 29, 30 of the first cylinder lens array 17, 28. And the cylinder axis is perpendicular to the cylinder axis of the cylinder lens of the third cylinder lens array. 15. The device according to claim 13 or 14, wherein the apparatus also comprises a fourth cylinder lens array, the fourth cylinder lens array facing the second cylinder lens arrays 20, 31. 27. The cylinder lenses 21, 22 of the second cylinder lens array 20, 31, comprising convex and concave cylinder lenses disposed on the sides of 27 and alternately arranged next to each other. , 32, 33, characterized in that the cylinder axis is arranged perpendicular to the cylinder axis of the cylinder lens of the fourth cylinder lens array. A first cylinder mirror array, wherein light to be homogenized can be reflected by the first cylinder mirror array, the first cylinder mirror array comprising convex and concave cylinder mirrors with cylinder axes parallel to each other, the cylinder mirrors A first cylinder mirror array, arranged alternately next to each other; And A second cylinder mirror array, wherein light reflected by the first cylinder mirror array can be reflected by the second cylinder mirror array, the second cylinder mirror array having convex and concave cylinder mirrors with cylinder axes parallel to each other. Wherein the cylinder mirrors comprise a second cylinder mirror array, alternately disposed next to each other, the cylinder axis of the cylinder mirror of the second cylinder mirror array being at the cylinder axis of the cylinder mirror of the first cylinder mirror array. In a light equalization device, aligned parallel to Wherein the concave cylinder mirror of the first cylinder mirror array is in a direction different from the concave cylinder mirror of the second cylinder mirror array in a direction in which the cylinder mirrors are arranged next to each other, In particular having different lengths and / or different curvatures.

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