Patent Application
20130301271
The present invention relates to an improvement of a marking light device for the emission of a standard light plane in, for example, a horizontal direction or a vertical direction. Such marking light devices are principally used if horizontal accuracy or vertical accuracy of a structure or of a building is intended to be set or confirmed, for example in a construction area, or if the horizontality of a ceiling, of a floor, of a design or of a part of a room is intended to be set.
Marking light devices for producing a standard light plane, which can in turn produce a line on a surface, are known from the prior art. In particular, such marking light devices are known which have an optical unit having a light source for producing a collimated light beam and having an optically deflecting element. An optically deflecting element can produce from a collimated light beam a light plane, that is to say a light pattern that uniformly radiates radially from a point—the origin of the light plane—in a plane. This takes place, in accordance with a first alternative, by expansion of the collimated light beam into a continuous light plane by the optically deflecting element, for example of a conical lens, or, in accordance with a second alternative, by rotation of a light beam about an axis of rotation by a rotating optically deflecting element, wherein the axis of rotation runs orthogonally with respect to the direction of propagation of said collimated light beam.
Embodiments in accordance with the first alternative, that is to say marking light devices having a conical lens, have been described inter alia in DE 602 02 114 T2 or JP-A-2000-18946. In the case of conical lenses, a distinction is made between convex conical lenses and concave conical lenses: the convex conical lens is substantially a cylinder-symmetrical cone whose lateral surface and base surface form an angle of 45°, wherein the lateral surface is suitable for deflecting a light beam. The concave conical lens has a central conical depression in a top surface of a substantially cylindrical body composed of light-transmissive material, wherein the lateral surface of the conical depression is suitable for deflecting a light beam.
Embodiments in accordance with the second alternative, that is to say marking light devices for producing a standard light plane by means of a rotating light beam, have been described for example in DE10116018 A1 and DE10054627 A1.
In such marking light devices, the optical unit is protected against external, in particular mechanical, influences by a cap. Said cap can have windows which consist of light-transmissive material and are arranged such that a large part of the light of the standard light plane produced passes out of the device through the windows of the cap.
Furthermore, such marking light devices have a cardan-type suspension, to be precise for orienting the standard light plane with respect to the perpendicular. The optical unit can be fixedly connected to the cardan-type suspension and be tiltable about two orthogonally intersecting axes of rotation. The cardan-type suspension can furthermore have motors, an inclination sensor (“spirit level”), and a microprocessor. The inclination sensor can determine the inclination of the standard light plane with respect to the perpendicular and communicate this to the microprocessor, which can drive the motors of the cardan-type suspension such that the standard light plane is oriented orthogonally with respect to the perpendicular. It should be noted that the relative position and orientation of the optical unit with respect to the cap, which is fixedly connected to the housing of the device, changes as a result of the orientation of the light position.
The prior art published before this application has the following problems, inter alia:
A first problem is that a cap having a plurality of windows has webs between the windows. The windows are planar and, in a manner connected by the webs, enclose the optical unit. However, said webs are light-opaque and produce a shadow, that is to say that they interrupt the standard light plane. By way of example, such a device having a substantially rotationally symmetrical cap having four windows has four webs. Such a cap can substantially have the form of a truncated pyramid. The standard light plane is therefore interrupted four times and the light line produced by the standard light plane on a surface is therefore not continuous. If precisely a location at which an interruption of the light line is present on account of the webs is essential for a measurement, the device has to be slightly rotated. This can in turn lead to a misalignment of the device, i.e. a tilting or changing of the height.
A second problem is that a beam bundle of the standard light plane impinges on the cap windows with different, location-dependent angles of incidence. This is caused, inter alia, by the fact that the housing, and thus the cap, can be situated in a manner tilted with respect to the perpendicular. In that case, as described above with regard to the cardan-type suspension, the position of the light plane changes with respect to the cap and the light plane impinges on the cap windows at different locations with different angles of incidence. The cap windows are plane-parallel layers having a higher refractive index (for quartz glass for instance nglass=1.46) than air (nair=1.00). In accordance with Snell's law of refraction, a light beam or a light plane which passes through such a cap window—that is to say a plane-parallel layer—is offset in a parallel manner depending on the angle of incidence. That is to say that, on account of the dependence on the angle of incidence and on account of said location-dependent angle of incidence, the standard light plane after passing through the cap windows is no longer exactly planar, but rather disturbed. The standard light plane no longer forms a planar surface or exact plane—an obviously undesirable effect for high-precision measurement tasks.
It is evident from the schematic sectional view in accordance with
It is evident from the schematic plan view in accordance with
The present invention is intended to provide an improved marking light device which an optically deflecting element and a cap designed according to standpoints of an optimum beam path that solves the problems described above.
The invention relates to a marking light device for producing a standard light plane. The marking light device can comprise: an optical unit having a light source for producing a first light beam and having an optically deflecting element for producing a first light plane from the first light beam; and a cap for producing the standard light plane from the first light plane. The optically deflecting element can be tiltable about a first axis of rotation and a second axis of rotation. As a result of a tilting of the optically deflecting element, the standard light plane is also tilted spatially, as a result of which, for example, the standard light plane can be oriented with respect to the perpendicular after the construction of the marking light device according to the invention.
The cap of the marking light device can have a continuous window. A continuous window according to the present invention is a window having one surface and two edges, wherein the thickness of the surface can vary locally. In particular, the continuous window can be rotationally symmetrical, that is to say that the surface of the window can be a lateral surface, it not being ruled out that the thickness of the surface can vary locally. The window can consist of light-transmissive material, for example of plastic, pressed glass or cut glass. Moreover, the window can be, inter alia, an integral part of the cap or a separate part of the cap, which is either fixedly connected to the cap or removable. This embodiment is associated with the advantage that the cap has a type of 360° panoramic window without webs. As a result, a standard light plane without gaps can be produced, which can in turn produce a continuous line on surfaces of an object to be measured.
The standard light plane can be situated in a planar surface. In particular, the entire standard light plane can be situated in a planar surface for any possible tilting position of the reflective element or of the entire optical unit, that is to say without spatial-direction-dependent parallel displacement of the light bundles of the standard light plane. The standard light plane can be situated in the same planar surface as the second light plane. The standard light plane can be situated in a planar surface that runs parallel to the planar surface of the second light plane. However, the standard light plane can also be situated in a planar surface that runs in a manner tilted with respect to the planar surface of the second light plane. This embodiment is distinguished by the accuracy of its standard light plane produced. In contrast to marking light devices in accordance with the prior art, the standard light plane is actually situated in a planar surface—independently of the relative position of the reflective element with respect to the cap.
In further embodiments, the first axis of rotation, the second axis of rotation and an axis of symmetry of the cap can in each case run orthogonally with respect to one another and intersect at a pivot point. The axis of symmetry can be an axis of cylinder-symmetry, for example, if the cap is cylinder-symmetrical. However, the axis of symmetry can also be an axis of rotational symmetry if the cap has an axis of rotational symmetry. Typically, this axis of symmetry also runs through the center of gravity of the cap. The pivot point can lie substantially at a point of intersection between the first light beam and the first light plane. At the same time or alternatively, said pivot point can also lie substantially at an origin of the first light plane. In this case, the point of intersection between the first light beam and the standard light plane is not taken to mean the point of intersection of real light beams, but rather is taken to mean the point of intersection between an axis running along the direction of propagation of the first light beam and a planar surface in which the first light plane lies. Furthermore, the origin of the first light plane is taken to mean the point at which all axes of the beam bundles that produce the first light plane intersect. This embodiment entails the advantage that, as a result of advantageous positioning of the pivot point, the origin of the first light plane does not change with respect to the cap, to be precise for any possible rotational position of the reflective element or of the entire optical unit. This facilitates the design of a cap which produces from the first light plane a standard light plane situated in a planar surface. By way of example, such a cap in accordance with this embodiment can have a continuous window which is cylinder-symmetrical, whose surface facing the pivot point has at every position an identical distance between origin of the standard light plane and pivot point and which has the same thickness at every position.
In further embodiments, the pivot point can can lie within the optically deflecting element. As a result, the pivot point lies near or at the origin of the standard light plane. These embodiments entail the advantage that, as a result of advantageous positioning of the pivot point, the origin of the standard light plane does not change or hardly changes with respect to the cap, to be precise for any possible rotational position of the reflective element or of the entire optical unit. In accordance with these embodiments, too, the design of a cap which produces from the first light plane a standard light plane situated in a planar surface is facilitated. In accordance with this embodiment, such a cap can have a continuous window which is cylinder-symmetrical and which has substantially the same thickness at every position. In this case, the cap can have a form such that that surface of the continuous window of the cap which faces the pivot point and the first light plane form the same angle for any tilting position and at every location. By way of example, the surface facing the pivot point can have at every position a substantially identical distance between origin of the first light plane and pivot point. A further advantage that can additionally be afforded is that the pivot point can lie near the origin of the standard light plane rather than directly at said origin. As a result, it is possible to use a conventional cardan-type suspension for tilting the optically deflecting unit, which does not even partly block the beam path of the first light plane.
In further embodiments, the light source and the reflective optical element can be arranged fixedly with respect to one another, such that the entire optical unit is tiltable about the first axis of rotation and the second axis of rotation. These embodiments are advantageous because the arrangement of the light source relative to the reflective element does not change, as a result of which a higher degree of accuracy is achieved during the beam orientation.
In further embodiments, the continuous window of the cap can be cylinder-symmetrical. These embodiments are advantageous because they allow a simple shaping of the cap which achieves the desired effect: producing a continuous standard light plane which is situated in a planar surface.
In further embodiments, the first light plane can intersect a cap entrance surface of the continuous window, wherein at each point of intersection between the light plane and the cap entrance surface, independently of a tilting position of the optically deflecting element, substantially a constant angle is formed between the light plane and the cap entrance surface. This embodiment is advantageous because it is thereby possible to use a cap having a continuous cap window which has the same thickness at every location. Each beam bundle of the first light plane is offset substantially by the same length and a standard light plane which lies in a planar surface arises.
In further embodiments, the standard light plane can be substantially collimated with respect to a first axis running orthogonally with respect to the first standard light plane. These embodiments are advantageous because the standard light plane expands as little as possible in the spatial direction that is important for the measurement, which is in turn associated with a higher accuracy of the measurement by means of the standard light plane.
In further embodiments, the continuous window of the cap can have a locally variable thickness and/or can have a locally variable refractive index. By means of the locally variable thickness and the locally variable refractive index, by way of example, the standard light plane can be produced from the first light plane such that it lies in a planar surface and that it is substantially collimated with respect to a first axis running orthogonally with respect to the first standard light plane.
In further embodiments, the optically deflecting element can be embodied as a concave conical lens. The concave conical lens can have a conical depression in a top surface of a substantially cylindrical lens body composed of light-transmissive material, wherein the lateral surface of the conical depression, the concave conical lens conical surface, is suitable for reflecting a light beam. In this case, the concave conical lens can have the following: a concave conical lens entrance surface, the base surface of the cylindrical lens body, for producing a second light beam from the first light beam; the concave conical lens conical surface for producing a second light plane from the second light beam; and a concave conical lens exit surface, the lateral surface of the lens body, for producing a first light plane from the second light plane. Furthermore, the continuous window of the cap can have the following: a cap entrance surface, the surface facing the concave conical lens, for producing a cap light plane from the first light plane; and a cap exit surface, the surface facing away from the concave conical lens, for producing the standard light plane from the cap light plane. Advantageously, firstly, the concave conical lens entrance surface, the concave conical lens conical surface, the concave conical lens exit surface, the cap entrance surface and the cap exit surface can have forms (for example planar, convex, concave or any other beam-shaping form) and, secondly, the concave conical lens and the continuous window of the cap can have refractive indices such that the standard light plane is substantially collimated with respect to a first axis running orthogonally with respect to the first standard light plane, and such that the standard light plane is substantially situated in a planar surface.
In further embodiments, the optically deflecting element can be embodied as a convex conical lens. The convex conical lens can substantially be a cylinder-symmetrical cone whose lateral surface, a convex conical lens lateral surface, and whose base surface form an angle of 45°, wherein the lateral surface is suitable for reflecting a light beam. Typically, the convex conical lens is arranged fixedly with respect to the rest of the components of the optical unit. In order to produce the standard light plane which is continuous, that is to say uninterrupted over 360°, the convex conical lens, in contrast to the concave conical lens, can be connected to the rest of the optical unit via a transparent element. According to the present invention, said transparent element should be regarded as part of the optically deflecting element and can be configured as a hollow cylinder without base and top surfaces. In this case, the convex conical lens can have the following: a convex conical lens conical surface for producing a third light plane from the first light beam; a convex conical lens entrance surface, the inner surface of the hollow cylinder, for producing a second light plane from the third light plane; and a convex conical lens exit surface, the outer surface of the hollow cylinder, for producing a first light plane from the second light plane. In this case, the continuous window of the cap can have the following: a cap entrance surface, the surface facing the convex conical lens, for producing a cap light plane from the first light plane; and a cap exit surface, the surface facing away from the convex conical lens, for producing the standard light plane from the cap light plane. Advantageously, firstly the convex conical lens conical surface, the convex conical lens entrance surface, the convex conical lens exit surface, the cap entrance surface and the cap exit surface can have forms (for example planar, convex, concave or any other beam-shaping form) and, secondly, the convex conical lens and the continuous window of the cap can have a refractive index such that the standard light plane is substantially collimated with respect to a first axis running parallel to an axis of cylinder-symmetry of the conical lens, and such that the standard light plane is substantially situated in a planar surface.
In further embodiments, the reflective element can be embodied as a pentaprism. In this case, the pentaprism can be rotatable about an axis of rotation for producing a first light plane from the first light beam, wherein the axis of rotation runs coaxially with respect to the first light beam. In this case, the continuous window of the cap can have the following: a cap entrance surface for producing a cap light plane from the first light plane; and a cap exit surface for producing the standard light plane from the cap light plane. Advantageously, firstly, the pentaprism, the cap entrance surface and the cap exit surface can have forms (for example planar, convex, concave or any other beam-shaping form) and, secondly, the pentaprism and the continuous window of the cap can have a refractive index such that the standard light plane is substantially collimated with respect to a first axis running parallel to the first light beam, and such that the standard light plane is substantially situated in a plane.
In further embodiments, the optically deflecting element can produce a first light plane, which diverges with respect to a first axis running orthogonally with respect to the first standard light plane. The cap can then produce from the first light plane the standard light plane which is substantially collimated with respect to the first axis. These embodiments entail the advantage that a standard light plane with an optimum beam shape can be produced with the aid of the reflective element and the cap. In particular, the divergence of the standard light plane with respect to the first axis can be minimized by an optimum beam shape.
In further embodiments, the light source can have a light diode for producing a divergent light beam and a lens for collimating the divergent light beam into a first light beam. Said first light beam can be divergent or convergent or collimated.
In further embodiments, the optical unit can be mounted in a manner tiltable about the pivot point by means of a cardan-type suspension.
In further embodiments, the cardan-type suspension can have an inclination sensor for determining the inclination of the optical unit with respect to the perpendicular and motors for setting the inclination of the optical unit with respect to the perpendicular. These embodiments entail the advantage that the optical unit or the second light plane and the standard light plane can always be oriented with respect to the perpendicular.
With reference to the drawings, the invention is explained thoroughly below by way of example on the basis of exemplary embodiments. The description, the associated figures and the claims contain numerous features in combination. A person skilled in the art will also consider these features, in particular also the features of different exemplary embodiments, individually and combine them to form expedient further combinations. In the figures:
The present invention provides a marking light device for producing a standard light plane 410 comprising an optical unit, having an optically deflecting element 200 and a light source 100, and comprising a cap 300, which solves the problems illustrated in
In the preferred embodiment of a marking light device according to the present invention, the light source 100 and the reflective optical element 200 are arranged fixedly with respect to one another, such that the entire optical unit is tiltable about the first axis of rotation and the second axis of rotation. For this purpose, the optical unit is suspended by means of a cardan-type suspension that allows a tilting of the optical unit with respect to the cap 300 about the first and second axes of rotation by up to +−15° in each case.
In an alternative embodiment, it is also possible for the optical unit on a cardan-type suspension not to be oriented with respect to the perpendicular by means of motors and an electronic inclination sensor. Instead, the optical unit can be oriented with respect to the perpendicular in a freely oscillating manner by means of an advantageous weight distribution. This process can be accelerated by the cardan-type suspension having an eddy current brake.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 042 430.7 | Oct 2010 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP11/66311 | 9/20/2011 | WO | 00 | 7/24/2013 |
