Device and method for projecting a marking onto a boundary

Abstract

The invention concerns a device for projecting a linear optical marking onto at least one boundary of a room, such as floor surface for example, comprising a light source (12) that emits laser radiation along an optical axis (16) as well as a cuboid lens (14) connected in series with the light source, penetrated by the optical axis and reflecting as well as refracting the radiation. To facilitate fanning and reflecting of light originating from the light source through constructively simple means, the invention proposes that provided in the frontal surface (20) is a channel-shaped depression (40) and provided in the rear surface (22) is a projection (24), both of which are geometrically designed and arranged so that the radiation can be totally reflected and that totally reflected radiation striking the depression can be fanned out, where the optical marking runs to both transverse surfaces of the lens.

Description

Additional details, advantages and features of the invention can be derived not only from the claims and the features described therein—on their own and/or in combination with one another, but also from the following description of a preferred embodiment illustrated in the drawing.

Shown are:

FIG. 1 A schematic diagram of a device for projecting a marking on a boundary surface,

FIG. 2 A side view of a lens,

FIG. 3 A rear view of the lens shown in FIG. 2,

FIG. 4 Lenses of the type shown in FIG. 2 with schematic illustration of radiation refracted, reflected and fanned thereby and

FIG. 5 A schematic illustration of the optical path for projecting the marking onto a boundary.

To project lines onto a floor surface 10 of a room for the purpose of aligning tiles, floor plates or other floor coverings to be laid, especially in the field of construction, a device with essential components schematically illustrated in FIG. 1 is used. The device comprises a light source such as the laser diode 12 with optics connected in series to allow a preferably ovular or elliptical cross-section beam, the optical axis 16 of which runs inclined toward the horizontal axis 18, to strike a lens 14. The angle of inclination β is preferably around 2°. However, the teaching of the invention is not restricted to this figure.

The laser beam, in this case the optical axis 16, strikes the lens 14 at a distance A from the floor surface 10, where this distance is preferably around 50 mm. The lens 14 is geometrically designed and aligned with the laser beam, in this case the optical axis 16, so that in the corresponding illustrations of FIGS. 4 and 5 a line is projected onto the floor 10 both in front of and behind the lens and hence also the laser light source 12. For this purpose, the lens 14 features a cuboid geometry with a length L, a width B and a depth T. Exemplary dimensions are: 12 mm≦L≦14 mm, 4 mm≦B≦6 mm and 3 mm≦T≦3.5 mm.

The lens 14 features a frontal surface 20 and a rear surface 22 in relation to the light source 12. Furthermore, a projection 24 with a triangular profile and protruding beyond the rear surface 22 divides the lens 14 into an upper first section 26 and a lower second section 28. The projection 24, which runs the entire width B of the lens 14 and parallel to both the upper and lower boundary surfaces (top surface 30, base surface 32), divides the lens 14 in relation to its height into two approximately equal parts, meaning that the sections 24, 26 are approximately equal in length. The rear surface 22 also features two planar areas 34, 36, which merge at a surface 38. Thus when the lens 14 is in the operating position, the angle between the vertical axis and the upper area 26 is δ, while the angle between the vertical axis and the lower area 28 is γ, where δ<γ.

Running on the frontal surface 20 at the level of the surface 38 is a depression 40, which is of channel-shaped geometry and runs parallel to the projection 24 as well as to the upper and lower boundary surfaces 30, 32.

The laser beam, which preferably features an elliptical cross section, where the major axis can be 3 to 5 mm, for example, and the minor axis can be 1 mm to 1.5 mm smaller than the major axis, strikes the frontal surface 20 of the lens 14, specifically at the upper first section 26. The optical axis 16 preferably intersects the contact surface 42 at an angle α, where α≠90°. Thus the optical axis 16 should intersect the surface 40, namely its area running to the top surface 30, at an obtuse angle.

Furthermore, FIG. 2 shows that the upper boundary surface, in this case the top surface 30 of the lens 14, is composed of two sections 44, 46, both of which are planar. Arranged opposite to this surface and exhibiting a concave form is the lower boundary surface, in this case the base surface 32.

The geometry of the lens 14, its design and its alignment to the optical axis 16 in the operating position facilitate the refraction, reflection and fanning of the striking radiation as illustrated in FIGS. 4 and 5. The line projected onto the floor 10 extends up to 10 m in front of the lens 14. The portion of the optical marking running in the direction of the light source 12 has a length that extends to behind the light source 12, as the schematic illustration of FIG. 5 shows.

FIG. 4 shows the trajectory of the beams of the radiation refracted, reflected and fanned by the lens 14. Here the projection 24 as well as the depression 40 running on the frontal surface 20 are essential for projecting the marking onto the floor surface 10. In this way, the radiation is totally reflected at the respective transitional area between the projection 24 and the bordering area of the rear surface 22 (points 48, 50), to be reflected in the direction of the depression 40 in which the radiation is further fanned. The radiation is also reflected by the inner surface of the surface 38 back into the direction of the light source 12 as well as into the area below it.

A portion of the radiation totally reflected in the area 50 is totally reflected at the frontal surface 20 below the depression 40 and refracted by the base surface 32 of the lens 14 so that the desired fanning of the radiation and thus the projection of the line onto the floor surface 10 is ensured.

Also essential for projecting the marking is the first or upper section 26 of the lens 14 with the transverse boundary surfaces, in this case frontal and rear surfaces 20, 22, that decrease in distance from one another as they approach the top surface 30 and thereby virtually constitute borders of a wedge, the projection 24 on the rear surface 26 dividing the lens 14 into the upper and lower sections 36 and 28 as well as the depression 40 running in the lower section 28 of the frontal surface 20.

Claims

1. Device for projecting a linear optical marking onto at least a boundary (10) of a room, such as a floor surface, comprising a light source (12) that emits light radiation—such as laser radiation—along an optical axis (16), as well as a cuboid lens (14) connected in series with the light source, which both reflects and refracts the radiation, is penetrated by the optical axis, and features frontal and rear surfaces as transverse surfaces, which run at an angle to the optical axis, characterized by the fact that in at least one transverse surface (20) a channel-shaped depression (40) and in at least one transverse surface (22) a projection (24) are provided, which are geometrically designed and arranged so that radiation striking the transitional area between the projection and the transverse surface is totally reflected, and totally reflected radiation striking the depression can be fanned out, where the optical marking runs to both transverse surfaces of the lens.

2. Device as claimed in claim 1, characterized by the fact that the projection (24) is provided on the rear surface (22) facing away from the lens.

3. Device as claimed in claim 1, characterized by the fact that the depression (40) is provided on the frontal surface of the lens (20).

4. Device as claimed in claim 1, characterized by the fact that the lens (14) is composed of a first and second section (26, 28), that the projection (24) runs in the transitional area between the first and second segments, that the first segment (26) is of trapezoidal geometry in a sectional plane in which the optical axis (16) penetrates the lens (14) and that the channel-shaped depression (40) is provided in the second section (28).

5. Device as claimed in claim 4, characterized by the fact that in the transverse surface (22) opposite the depression (40) an additional depression is provided and that emanating from the depression, the second section (28) features a trapezoidal geometry with a concave running free outer base surface (32), constituting in particular the lower outer surface of the lens (14).

6. Device as claimed in claim 4, characterized by the fact that the outer free base surface (30) of the first section (26) is preferably designed as a planar upper outer surface of the lens (14) and, in particular, is parallel or nearly parallel to the horizontal axis (18) when the lens is in the operating position.

7. Device as claimed in claim 4, characterized by the fact that the outer free base surface (30) of the first section (26) is preferably realized as the upper outer surface of the lens (14) composed of multiple planar surfaces (44, 46), of which at least one is horizontal or nearly horizontal when the lens is in the operating position.

8. Device as claimed in claim 1, characterized by the fact that the first section (26) of the front surface (20) runs inclined toward the optical axis (16).

9. Device as claimed in claim 4, characterized by the fact that the lens (14) is aligned with the light source (12) in such a way that the optical axis (16) strikes the first section (26) at an angle α≠90°.

10. Device as claimed in claim 9, characterized by the fact that the optical axis (16) runs in z relation to the horizontal axis (18) at an angle β, where 1°≦β≦3°.

11. Device as claimed in claim 1, characterized by the fact that the optical axis (16) intersects the frontal surface (20) at the area (34) emanating from the upper outer surface (30) of the lens (14) to form an obtuse angle.

12. Device as claimed in claim 1, characterized by the fact that the lens (14) features a width B, a length L and a depth T, where in particular 2 B≦L≦3 B and/or 2 T≦L≦4 T and/or 1 T≦B≦2 T.

13. Device as claimed in claim 1, characterized by the fact that the projection (24) runs in the center of the transverse surface (22).

14. Device as claimed in claim 1, characterized by the fact that the projection (24) has a triangular-shaped cross section and extends over the entire width of the transverse surface (22).

15. Device as claimed in claim 1, characterized by the fact that the transverse surface (22) featuring the projection (24) is preferably composed of a first area (34) having an angle δ to the vertical axis (14) when the lens is in the operating position and a second area (36) having an angle γ to the vertical axis when the lens is in the operating position, where δ<γ, that the projection emanates from the first area, and that the second area merges with the first area via a diagonally running surface (38).

16. Device as claimed in claim 1, characterized by that the lens (14) is arranged with its first depression (40) reflecting the radiation back in the direction of the light source (12) or fanning it spaced from the boundary at a distance A, where 20 mm≦A≦100 mm, in particular 30 mm≦A≦70 mm.

17. Method for projecting a linear optical marking onto at least a boundary (10) such as a floor surface of a room by fanning a light radiation, such as laser radiation, emitted from a light source (12) and at least partly reflecting and refracting it at or in an optical lens (14), whereby radiation is reflected and refracted in such a way that the optical marking is projected both in front of and behind the light source, characterized by the fact that a cuboid lens (14) with frontal and rear surfaces as transverse surfaces (20, 22) is used, which runs at an angle to the optical axis (16) of the radiation striking the lens, where in at least one transverse surface a channel-shaped depression (40) and in at least one transverse surface a projection (24) are provided, which are geometrically designed and arranged so that radiation striking the transitional area between the projection and the transverse surface is totally reflected, and totally reflected radiation striking the depression is fanned out.

18. Method as claimed in claim 17, characterized by the fact that radiation is totally reflected by the projection (24) realized on the rear surface (22) facing away from the lens in the transitional area between a first section (26) of the rear surface and the projection, that radiation totally reflected in this way is totally reflected and fanned in the transitional area between the projection and a second section (26) of the rear surface and that a portion of the fanned radiation is further fanned in the channel-shaped depression (40) provided in the frontal surface (20) of the lens.

19. Method as claimed in claim 17, characterized by the fact that the projection (24) and the bordering areas of the lens (14) are geometrically adapted to one another in such a way that radiation is totally reflected on a first transitional area between the projection and the bordering rear surface (22) and into a second transitional area between the projection and the bordering rear surface and is totally reflected by the second transitional surface in the direction of the frontal surface.

20. Method as claimed in claim 19, characterized by the fact that the radiation totally reflected for the second time or at least a portion thereof is reflected in the direction of the depression (40), where it is then fanned out.

21. Method as claimed in claim 17, characterized by the fact that radiation reflected by the projection (24) in the direction of the frontal surface (20) is both fanned in the direction of the light source (12) and reflected and fanned by the frontal surface in the direction of the rear surface (22).