Abstract:
The disclosure is based on a hand-held laser distance measuring device comprising at least one laser unit which is configured to determine a first distance using a laser beam emitted in a first relative direction. The laser unit is further configured to determine at least one second distance, near instantaneously, using a laser beam emitted in at least one second relative direction which differs from the first relative direction.

Description:
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2011/070734, filed on Nov. 23, 2011, which claims the benefit of priority to Serial No. DE 10 2010 056 156.8, filed on Dec. 28, 2010 in Germany, and to Serial No. DE 10 2011 005 277.1, filed on Mar. 9, 2011 in Germany, the disclosures of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     The disclosure proceeds from a handheld laser distance measuring device as described herein. 
     A handheld laser distance measuring device comprising at least one laser unit, which is provided to determine a first distance in a first relative direction using a laser beam, has already been proposed. 
     SUMMARY 
     The disclosure proceeds from a handheld laser distance measuring device comprising at least one laser unit, which is provided to determine a first distance in a first relative direction using a laser beam. 
     It is proposed that the laser unit is provided to determine, almost simultaneously, at least one second distance in at least one second relative direction, which differs from the first relative direction, using a laser beam. In particular, “handheld” should be understood to mean that the laser distance measuring device is provided to be at least guided, preferably be carried, manually by an operator during a measurement process. The laser distance measuring device preferably has a mass of less than 2 kg, particularly preferably less than 1 kg. In particular, a “laser unit” should be understood to mean a device which is provided to emit a laser beam with more than 50% of its power within an aperture angle of less than 2 degrees, advantageously less than 0.5 degrees, particularly advantageously less than 0.1 degrees. The laser unit preferably has a laser whose laser beam is pivoted to-and-fro, in particular continuously, between the two relative directions; to be precise, in particular with a frequency of greater than 2 Hz, preferably greater than 10 Hz, particularly preferably greater than 20 Hz. Alternatively, or in addition thereto, the laser unit could have at least two lasers and/or at least two sensors, which are respectively provided to determine the distance in different relative directions. In particular, “provided” should be understood to mean specifically programmed, designed and/or equipped. In particular, a “relative direction” should be understood to mean a direction relative to a housing of the laser distance measuring device. Hence the laser distance measuring device almost simultaneously determines distances to at least two different measurement points. The laser unit is preferably provided to determine distances in at least three relative directions, advantageously in at least four relative directions, particularly almost simultaneously. The laser unit is preferably provided to determine, particularly almost simultaneously, a determined number of distances, in particular a number which can be set by an operator, with different relative directions on a plane within an angular range. The laser unit preferably captures an alignment of the relative directions, in particular relative to one another and/or advantageously relative to a housing of the laser distance measuring device. Alternatively, or in addition thereto, the laser unit is provided to capture, control and/or preferably regulate an angle between the at least two relative directions. In this context, a “distance” should be understood to mean a path length between the laser unit and a measured surface of a measurement object, which at least partly reflects the laser beam in the direction of the laser unit during a measurement. The laser unit preferably comprises a sensor, which is provided to capture some of the light reflected by the measured surface. The sensor preferably comprises several photodetectors, which receive reflected light from several, different angular regions by a reception optical unit. The photodetectors are preferably arranged in two-dimensional fashion on a surface. Alternatively, a single photodetector of the sensor could receive reflected light from all relative directions and/or a single photodetector of the sensor could receive the reflected light by means of a semi-transparent and/or a minor transparent from one side, which is at least partly arranged in the non-reflected laser beam. The laser unit in particular preferably determines a run time of a laser pulse from the laser beam between an emission and a reception by the laser unit. Alternatively, or in addition thereto, the laser unit could determine the path to a different characteristic variable appearing useful to a person skilled in the art, for example by triangulation and/or by a phase shift, in particular of a signal modulated onto the laser beam. In this exemplary embodiment, “almost simultaneously” should, in particular, be understood to mean that the laser unit is provided to determine at least two distances within 500 ms, advantageously within 100 ms, particularly advantageously within 50 ms. Between determining the two distances, the laser unit remains, in particular, unmoved, in particular except for a laser beam guidance means. In this context, “different” should more particularly be understood to mean that, in at least one operating state, there should be an acute angle of greater than 5 degrees, advantageously of greater than 30 degrees, between the first relative direction and the second relative direction. As a result of the embodiment according to the disclosure of the laser distance measuring device, a convenient measurement of paths is possible with particularly small design complexity. In particular, the operator can measure a path between two points which can only be reached by the laser beam, without having to place the laser distance measuring device onto one of the points. In so doing, such a path can be measured particularly advantageously by pressing a button and/or within a short period of time, in particular within less than one second. The operator can, in order to measure the path, advantageously be situated at a position at a distance from the path. In addition to a path at a distance from the laser distance measuring device, the laser distance measuring device is provided to determine and output a distance between the laser unit and the measurement point using the laser beam. 
     In a further embodiment, it is proposed that the laser unit comprises a laser beam guidance means, which is provided to guide the laser beam into the different relative directions, as a result of which it is possible to determine a distance at several positions by means of a simple design using a single laser. A “laser beam guidance means” should be understood to mean a means appearing useful to a person skilled in the art, but preferably a spatial light modulator (SLM), a refractive optical unit, a mechanism for pivoting a laser of the laser unit, the sensor of the laser unit and/or an optical unit of the laser unit, a micromirror array with several micromirrors, but particularly preferably a single micromirror. In particular, a micromirror has a mirror surface of less than 4 mm 2 , advantageously less than 1 mm 2 , particularly advantageously less than 0.1 mm 2 . The mirror surface can preferably be pivoted toward at least one direction, preferably in two directions, by means of an electric signal, in particular via an electrostatic actuator. The laser beam guidance means preferably pivots the laser beam continuously over an in particular constant angular range. Individual measurement points could advantageously be achieved by cycling the laser and/or by a stop and could be marked for the operator by means of another laser, more particularly having a different color. In this case, a laser determining the distances could be invisible. 
     Moreover, it is proposed that the laser distance measuring device comprises a computer unit, which is provided to set an angle at least between the first relative direction and the second relative direction, as a result of which a particularly precise, fast and flexibly adjustable alignment of the relative directions of the laser beam or the laser beams is possible. A “computer unit” should in particular be understood to mean a unit with an information input, information processing and an information output. The computer unit advantageously comprises at least one processor, input interfaces, output interfaces and/or, advantageously, operating programs, regulating routines, control routines and/or calculation routines stored in a memory of the computer unit. In particular, the term “set” should be understood to mean that the computer unit outputs at least one characteristic variable, which is provided to control and/or to regulate the laser beam guidance means for adjusting the relative direction. 
     It is furthermore proposed that the computer unit is provided to regulate the laser beam guidance means in an operating mode by virtue of a measurement point of the first relative direction and a measurement point of the second relative direction being arranged at a predetermined distance from one another, as a result of which an operator can display and check paths on an surface in a particularly convenient manner. By way of example, the operator can check very quickly whether a cabinet with a given width fits into an available niche. An “operating mode” should be understood to mean an operating state, at least of the computer unit, which can be influenced by an operator by virtue of the computer unit executing regulating routines, control routines and/or calculation routines which can be selected by a user. The computer unit is preferably provided to execute different ones thereof. In this context, “regulating” should in particular be understood to mean that the computer unit determines a distance between the two measurement points, compares the determined distance with the distance prescribed by the operator in particular and then modifies the angle between the relative directions in such a way that the measurement points are arranged spaced apart at the predetermined distance. In particular, a “measurement point” should be understood to mean a region of the measured surface, which reflects the laser beam and is measured by the computer unit during operation. 
     Moreover, it is proposed that the laser distance measuring device comprises an input unit, by means of which an angle, at least between the first relative direction and the second relative direction, can be set, as a result of which a particularly convenient and versatile operation is possible. An “input unit” should, in particular, be understood to mean a unit, in particular with a haptic element, which is provided to provide a characteristic variable, which can be influenced by an operator, for mechanical and/or advantageously electric control of the computer unit and/or laser unit. 
     Furthermore, it is proposed that the laser distance measuring device comprises a computer unit which is provided to determine at least one contour of a measurement object, as a result of which a particularly convenient, fast and accurate determination of a path, starting from the contour, and/or at least one property of the contour, for example a radius, a focus of an ellipse, is possible. In particular, a “contour of a measurement object” should be understood to mean a bend, an edge, a hole and/or another change in a structure appearing useful to a person skilled in the art and/or an alignment of a measured surface along at least one path extending on the measured surface. The computer unit preferably measures, by means of the laser unit, a profile of the path on the measured surface and determines, by means of a calculation routine, a contour of the measured surface. 
     Moreover, it is proposed that the laser distance measuring device comprises a computer unit which is provided to determine at least one distance from a measured surface to a measurement point, as a result of which a particularly versatile operation is possible. In particular, a “distance from a surface to a measurement point” should be understood to mean a minimum distance between a plane spanned by the surface and the point. 
     Furthermore, it is proposed that the laser distance measuring device comprises a computer unit which is provided to determine an angle of intersection between at least two measured surfaces, as a result of which convenient measuring of angles can be achieved. In particular, in this context, an “angle of intersection” should be understood to mean an angle facing the laser unit between two planes spanned by the measured surfaces, which angle lies in a measurement plane spanned by the laser unit and measurement points. 
     In an advantageous embodiment of the disclosure, it is proposed that the laser unit is provided to generate at least one projection line, as a result of which a measured path can be displayed in a particularly advantageous manner. In particular, a “projection line” should be understood to mean a full and/or dotted line drawn on the measured surfaces by means of the laser unit. The laser unit advantageously generates the projection line continuously, for example by means of an optical unit. The laser unit particularly advantageously generates the projection line by virtue of repeatedly moving a laser point over the measurement object such that an operator perceives a line. The laser unit preferably comprises a laser with a first wavelength for determining the distances and/or for generating the projection line and at least one second laser with a second wavelength for marking measurement points, measured contours and/or other points appearing useful to a person skilled in the art. 
     Furthermore, it is proposed that the laser unit is provided to project a value of a length of a distance onto the measurement object in particular, as a result of which a particularly convenient display is possible. The laser preferably projects the value which determines at least the first distance. Alternatively, or in addition thereto, the laser unit has a projection laser, in particular with a different color, and/or another, in particular multicolored, projection device appearing useful to a person skilled in the art. Alternatively, or in addition thereto, the laser distance measuring device comprises a projector, in particular a DLP, LCD and LCoS projector, preferably with a light-emitting diode as light source. 
     Moreover, it is proposed that the laser distance measuring device comprises a position capture unit which is provided to capture at least one alignment of at least the laser unit in space, as a result of which trembling of a hand of the user is advantageously damped and further information relating to determining the path and/or alignment can be determined. In particular, a “position capture unit” should be understood to mean a unit which is provided at least to capture an alignment of at least the laser unit at least relative to gravity. The position capture unit is preferably also provided to establish an acceleration in a spatial direction and/or a rotation about an axis, which, for example, is aligned parallel to the direction of gravity in order to establish a horizontal path. By way of example, a perpendicular and/or horizontal arrangement of a measurement plane of the laser unit could be output to the user. 
     Furthermore, it is proposed that the computer unit is provided to calculate a further distance at least from an alignment captured by the position capture unit and two distances measured in a same relative direction, as a result of which the laser distance measuring device can be employed in a particularly versatile way. In particular, a surface can be calculated with a simple design using distances determined in two relative directions and the distance captured by the distance capture unit. Here, the laser plane of the laser unit is pivoted over the surface and it is measured thereby. The computer unit preferably captures during the pivoting contours delimiting the surface and aligns the relative directions accordingly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages emerge from the following description of the drawing. The drawing illustrates two exemplary embodiments of the disclosure. The drawing, the description and the claims contain several features in combination. A person skilled in the art will expediently also consider the features individually and combine these to form further useful combinations. 
       In detail: 
         FIG. 1  shows a handheld laser distance measuring device according to the disclosure and a measurement object, 
         FIG. 2  shows the laser distance measuring device from  FIG. 1  in a functional diagram, 
         FIG. 3  shows a second exemplary embodiment of the laser distance measuring device from  FIG. 1  in a schematic illustration, 
         FIG. 4  shows a laser beam guidance means of the laser distance measuring device from  FIG. 3  in a schematic illustration and 
         FIG. 5  shows the laser distance measuring device from  FIG. 3  in a further operating state. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a handheld laser distance measuring device  10   a  according to the disclosure, comprising a laser unit  12   a , an input unit  28   a , a display  50   a  and a housing  52   a . During a measurement operation with a laser beam  14   a , the laser unit  12   a  determines several distances almost simultaneously in different relative directions R 1   a -R 11   a .  FIG. 1  illustrates eleven exemplary relative directions R 1   a -R 11   a . An operator operates the laser distance measuring device  10   a  by means of the input unit  28   a . The display  50   a  shows measurement results to the user. It has a display driver (not illustrated in any more detail). 
       FIG. 2  shows that the laser unit  12   a  comprises a laser beam guidance means  18   a , a laser  54   a  and an actuation unit  56   a . During operation, the actuation unit  56   a  controls the power of the laser  54   a  and a deflection of the laser beam guidance means  18   a . The laser beam guidance means  18   a  comprises a MEMS-mirror. The actuation unit  56   a  is provided to tilt a micromirror  58   a  of the laser beam guidance means  18   a  about axes  60   a ,  62   a  aligned perpendicular to one another. Alternatively, the actuation unit  56   a  could tilt the micromirror  58   a  only about one axis and/or the actuation unit  56   a  could tilt two micromirrors, arranged in succession in the laser beam, respectively about one axis, which axes are aligned perpendicular to one another. By tilting the micromirror  58   a , the laser unit  12   a  guides the laser beam  14   a  in different relative directions R 1   a -R 11   a , i.e. in different directions relative to the housing  52   a , during a measurement process. 
     The laser unit  12   a  comprises a sensor  64   a  and a synchronization unit  66   a . The sensor  64   a  comprises an optical unit  68   a , photodetectors  70   a  and a read-out unit  72   a . The optical unit  68   a  guides light reflected from a measurement object  36   a  substantially onto one of the photodetectors  70   a , to be precise depending on the relative directions R 1   a -R 11   a . The optical unit  68   a  preferably comprises at least one micromirror array. The read-out unit  72   a  processes the signals from the photodetectors  70   a ; to be precise it amplifies the signals and serializes the signals. The synchronization unit  66   a  controls or regulates transmitting the laser beam  14   a  and, by means of the optical unit  68   a , receiving the reflected light of the laser beam  14   a . The synchronization unit  66   a  determines a characteristic variable, which depends on the distances and which is read by a computer unit  20   a.    
     The laser distance measuring device  10   a  comprises the computer unit  20   a  and a position capture unit  48   a . The computer unit  20   a  controls the display  52   a  and the synchronization unit  66   a  and queries the input unit  28   a . The computer unit  20   a  provides various measurement modes. The position capture unit  48   a  comprises a 3-axis acceleration sensor (not illustrated in any more detail) for capturing gravity and determining accelerations and gyroscopes for capturing rotational movements about all axes. The position capture unit  48   a  is connected directly to the actuation unit  56  for damping trembling movements of the operator. 
     In a first measuring mode, the laser unit  12   a  transmits the laser beam  14   a  along a central relative direction R 6 . From a run time of a pulse of the laser beam  14   a , the computer unit  20   a  determines a distance  74   a  between a measurement point P 6  of the measurement object  36   a  and the laser unit  12   a . The computer unit  20   a  displays a value of the distance  74   a  on the display  50   a  so that the operator can read it. Moreover, the computer unit  20   a  displays the value of the distance  74   a  on the measurement object  36   a  by virtue of the laser unit  12   a  projecting the latter onto the measurement object  36   a . To this end, the actuation unit  56  is connected to the display  50   a.    
     In a second measurement mode, the laser unit  12   a  alternately transmits the laser beam  14   a  into a first relative direction R 5  and into a second relative direction R 7 . The input unit  28   a  has a knob  76   a . By actuating the knob  76   a , the operator can set an angle  22   a  between the two relative directions R 5 , R 7 . The laser unit  12   a  comprises a sensor (not illustrated in any more detail), which captures the angle between the relative directions R 1   a -R 11   a  during operation. The computer unit  20   a  calculates a distance  26   a  between the measurement points P 5   a , P 7   a . To this end, the computer unit  20   a  uses an implementation of the cosine law. 
     In a third measurement mode, the operator provides a distance  26   a  between two measurement points P 5 , P 7  by means of the input unit  28   a . The computer unit  20   a  regulates an angle  22   a  between two relative directions R 5 , R 7 . As a result, the two measurement points P 5 , P 7  are arranged at the set intended distance from one another on a straight line. 
     In a fourth measurement mode, the operator sets an angle  24   a  between two outer relative directions R 1   a , R 11   a  by means of the input unit  28   a . The computer unit  20   a  sends the laser beam  14   a  into a number of relative directions R 1   a -R 11   a , which number can be set. Alternatively, or in addition thereto, it could be possible to set an angle  78   a  between two adjacent relative directions R 1   a -R 11   a . The computer unit  20   a  determines distances between adjacent measurement points P 1   a -P 8   a  and calculates, by forming sums, a length of a measurement path along the measurement object  36   a . If a distance between two adjacent measurement points exceeds a threshold and/or if a measurement in a relative direction R 9   a  is not possible, the computer unit  20   a  warns the operator by optical, acoustic and/or haptic means. The operator can select whether he ignores these circumstances or interrupts a measurement path at a measurement point P 8   a  which is adjacent and/or facing the center. Moreover, the computer unit  20   a  is provided to optimize the calculation of the path by filter routines, e.g. by “least-squares fitting”, appearing useful to a person skilled in the art. Moreover, the computer unit  20   a  is provided to calculate surfaces by virtue of multiplying two paths aligned perpendicular to one another, which paths were measured in succession and/or, advantageously, almost simultaneously. 
     In a further embodiment of the fourth measurement mode, the computer unit  20   a  has a calculation routine (not illustrated in any more detail) which determines contours  30   a ,  32   a ,  34   a  of a measurement object  36   a  during a measurement operation. By way of example, the calculation routine could have a RANSAC algorithm (Random Sample Consensus algorithm). The computer unit  20   a  has a regulating routine (not illustrated in any more detail), which aligns a measurement point P 1   a , P 3   a , P 8   a  precisely on a center of the captured contour  30   a ,  32   a ,  34   a . The laser unit  12   a  has a second laser (not illustrated in any more detail) with a color that differs from the first laser  54   a . By means of the second laser, the calculation routine  20   a  marks captured contours and paths selected for being measured. The laser unit  12   a  generates a projection line  46   a  by means of the first laser, which projection line indicates a position of the currently measured path. Alternatively, or in addition thereto, the laser unit  20   a  could almost simultaneously measure several paths separated by captured contours  30   a ,  32   a ,  34   a  and project the measurement results onto the measurement object  36   a  next to the paths. 
     In a fifth measurement mode, the computer unit  20   a  determines a perpendicular distance  38   a  from a surface  40   a  to a measurement point P 10   a , P 11   a  on another surface. To this end, the computer unit  20   a  measures an alignment of the surface  40   a  on the measurement plane, for example by two measurement points P 5   a , P 7   a , and the measurement point P 10   a , P 22   a  on the other surface. 
     In a sixth measurement mode, the computer unit  20   a  determines the alignment of two surfaces  40   a ,  44   a ; to be precise on the measurement plane of the laser unit  12   a . From the alignments, the computer unit  20   a  calculates an angle of intersection  42   a  between the two surfaces  40   a ,  44   a.    
     In a seventh measurement mode (not illustrated in any more detail), the computer unit  20   a  determines a movement of the laser unit  12   a ; to be precise, by means of the alignments and accelerations captured by the position capture unit  48   a . As a result, it is possible to determine the size of a surface by virtue of the operator pivoting the measurement plane of the laser unit  12   a  over the measurement object  36   a  by means of a manual movement. In so doing, the computer unit  20   a  calculates a further distance on the measurement object  36   a , to be precise in the pivot direction, from an alignment captured by the position capture unit  48   a  and two distances measured in a same relative direction R 1   a -R 11   a . The computer unit  20   a  automatically traces contours  30   a ,  32   a , which delimit the surface. 
     As an alternative or in addition to the seventh measurement mode, the computer unit  20   a  could measure the surface via a deflection of the laser beam  14   a  in two mutually perpendicularly aligned directions, as a result of which measurement points are arranged on the surface in two dimensions. Moreover, the position capture unit  48   a  assists the operator with a horizontal and/or vertical alignment of the laser unit  12   a  by virtue of indicating these alignments to the operator in an optical, acoustic and/or haptic fashion. To this end, the position capture unit  48   a  could, for example, comprise a vibration means. 
     In a further measurement mode (not illustrated in any more detail), the computer unit  20   a  captures a property of a contour. To this end, the computer unit  20   a  has a calculation routine which identifies a contour, for example a circular contour of a column. On the display, the computer unit  20   a  displays properties of the contour, such as e.g. a radius, a diameter, a base area and/or values, such as a volume, calculated from the properties. 
       FIGS. 3 to 5  show a further exemplary embodiment of the disclosure. The following descriptions and the drawings restrict themselves substantially to the differences between the exemplary embodiments, wherein, in respect of components that have been referred to in the same way, in particular in respect of components with the same reference signs, reference can also be made, in principle, to the drawings and/or the description of the other exemplary embodiments, in particular  FIGS. 1 and 2 . In order to make a distinction between the exemplary embodiments, the letter a has been appended to the reference signs of the exemplary embodiment in  FIGS. 1 and 2 . In the exemplary embodiment of  FIGS. 3 to 5 , the letter a has been replaced by the letter b. 
       FIGS. 3 and 4  show a handheld laser distance measuring device  10   b  with a laser unit  12   b , an input unit  28   b , a display  50   b  and a housing  52   b . The laser unit  12   b  comprises two lasers  54   b ,  80   b  and two sensors  64   b ,  82   b . The sensors  64   b ,  82   b  respectively comprise one photodiode  84   b  and one lens  86   b . Respectively one of the lasers  54   b ,  80   b  and one of the sensors  64   b ,  82   b  are mounted together in a pivoting fashion relative to the housing  52   b . An actuation unit  56   b  of the laser unit  12   b  couples a knob  76   b  of the input unit  28   b  and the lasers  54   b ,  80   b  for mechanically pivoting the lasers  54   b ,  80   b . To this end, the actuation unit  56   b  comprises a belt  88   b  and two rotary disks  90   b ,  92   b . Respectively one of the lasers  54   b ,  80   b  and one of the sensors  64   b ,  82   b  is assembled on each of the rotary disks  90   b ,  92   b . The rotary disks  90   b ,  92   b  interlock into one another. In terms of effect, the belt  88   b  connects the input unit  28   b  with one of the rotary disks  90   b . A person skilled in the art knows of further alternative connection methods. When the input unit  28   b  rotates, the rotary disks  90   b ,  92   b  rotate in opposite directions. Hence, the laser unit  12   b  is provided to determine respectively one distance in a first relative direction R 1   b  and a second relative direction R 2   b  by means of two laser beams  14   b ,  16   b  of the lasers  54   b ,  80   b . To this end, an angular sensor (not illustrated in any more detail) determines angles  20   b ,  22   b  of the rotary disks  90   b ,  92   b  and a computer unit (not illustrated in any more detail) calculates the distance between two measurement points P 1   b , P 2   b  of the laser beams  14   b ,  16   b . The operator triggers a measurement by pressing on a key  94   b.    
     In a second measurement mode, illustrated in  FIG. 5 , the lasers  54   b ,  80   b  and the sensors  64   b ,  82   b  are pivoted in relative directions R 1   b , R 2   b , which are aligned parallel to one another, and the laser beams  14   b ,  16   b  are emitted in opposite directions. As a result, the operator can measure distances between two points which are difficult to access in a particularly convenient and efficient fashion. In so doing, the rotary disks  90   b ,  92   b  are respectively pivoted out of the housing  52   b  about a rotational axis  96   b . Alternatively, the rotary disks could be pivoted arranged within the housing  52   b.