Abstract:
One or more lasers are used to create cones of laser light of varying angles. The lasers are visible on the flat surface as a series of arcs or complete circles of varying radius. In one embodiment, consecutive arcs spaced from a center on a perfectly flat surface increase in radius by a predetermined or constant amount. When the surface is not flat, but has a slope, the radius of adjacent circles become closer or further from each other, creating a virtual relief map appearance.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S)  
       [0001]    This application claims the benefit of U.S. Provisional Application Serial No. 60/433,944, filed Dec. 17, 2002, under 35 U.S.C. 119(e). 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to showing the slope of a surface, and in particular to a laser projector for illuminating the slope of the surface.  
         BACKGROUND OF THE INVENTION  
         [0003]    Detecting variations in the slope of a generally planar surface has been performed in many different manners. In the game of golf, golfers and their caddies will study a putting green for several minutes trying to determine the slope of the green and hence, which way a putted golf ball will move or break, as it is sent toward a golf hole. Golfers will bend down low to eyeball the green, moving to several different vantage points. Memory of previous puts also serves as a method to help determine the slope of the green, and hence the break of the ball. Some will hold their putter up, letting it hang in an assumed plum position between the ball and the hole as an aid to determining the break. There is a need for a more accurate and visible representation of the slope of the green.  
         SUMMARY OF THE INVENTION  
         [0004]    One or more lasers are used to create cones of laser light of varying angles. The lasers are visible on a flat surface as a series of arcs or complete circles of varying radius. In one embodiment, consecutive arcs spaced from a center on a perfectly flat surface increase in radius by a predetermined or constant amount. When the surface is not flat, but has a slope, the circles become closer or further from each other, creating a virtual relief map appearance.  
           [0005]    In one embodiment, the lasers are rotating lasers that are mounted about an axis that is placed perpendicular to a generally planar surface. The lasers are spaced and angled to create the arcs. In a further embodiment, one or more lasers create lines extending axially, intersecting the arcs. In still a further embodiment, the axis is self leveling, or has a level for visually leveling the axis by modifying the lengths of legs of a tripod supporting the axel. In a further embodiment, one or more batteries are utilized to power the lasers, or an AC converter is provided.  
           [0006]    In still a further embodiment, one or more lasers are used with beam splitters and/or mirrors mounted on gimbals to produce the arc patterns on the surface. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a front elevation block diagram of an example laser projector.  
         [0008]    [0008]FIG. 2 is a top view of the laser projector of FIG. 1 showing lasers reflecting light off a flat surface.  
         [0009]    [0009]FIG. 3 is a cross section of the laser projector of FIG. 1 illustrating laser projections on a contoured surface.  
         [0010]    [0010]FIG. 4 is a top view of the laser projector and contoured surface of FIG. 3. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]    In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims.  
         [0012]    The functions or algorithms described herein are implemented in software or a combination of software and human implemented procedures in one embodiment. The software comprises computer executable instructions stored on computer readable media such as memory or other type of storage devices. The term “computer readable media” is also used to represent carrier waves on which the software is transmitted. Further, such functions correspond to modules, which are software, hardware, firmware of any combination thereof. Multiple functions are performed in one or more modules as desired, and the embodiments described are merely examples. The software is executed on a digital signal processor, ASIC, microprocessor, or other type of processor operating on a computer system, such as a personal computer, server or other computer system.  
         [0013]    [0013]FIG. 1 is a side elevation view of an example embodiment of a laser projector  100  for projecting a pattern on a surface. The projector is supported by a tripod  105  which has means for adjusting the height of the projector. Such means include telescoping legs, and/or a pole  107  supporting the projector  100  at various heights above a top of the tripod. The projector  100  comprises multiple laser emitting sections  110 ,  115 ,  120 ,  125 ,  130 ,  135 ,  140  and more if desired as illustrated. The laser emitting sections in one embodiment comprise battery powered lasers that rotate about an axis of the projector  100 . In a further embodiment, a single laser is used with beam splitters and movably mounted mirrors in each section. The laser emitting sections project laser light at different angles toward a surface on which the projector is supported. The effect is to create multiple visible circles of laser light on the surface as seen in FIG. 2 at  210 ,  215 ,  220 ,  225 ,  230 ,  235  and  240 , corresponding to each of the sections having the same last two digits in FIG. 1.  
         [0014]    In one embodiment, the circles of laser light on the surface are concentric, having radii increasing equally. For example, the radius of circle  210  is defined as R. The radius of circle  215  is R+x. The radius of circle  220  is R+2x. The radius of circle  225  is R+3x. Circle  230  has a radius of R+4x, circle  235  has a radius of R+5x and circle  240  has a radius of R+6x. In one embodiment, R is variable, and depends at least on the height that the projector  100  is supported above the surface. Angles of the laser emitting sections may also be varied in a further embodiment, either by manual adjustment, or computer controlled adjustment of gimbals supporting lasers within the laser sections.  
         [0015]    The radius, R, and increase in radius, x, are referred to as parameters that are selected such that they provide meaningful illustration of the surface. In the case of the surface being a golf green, the parameters are selected to provide circles between a golf hole, and a ball to be putt. The projector may be supported by the tripod directly over the golf hole. In a further embodiment, the projector is supported by a single pole for matting a bottom of a golf hole in the same manner as a golf flag is supported by the hole. In further embodiments the projector is used illustrate ground in landscaping projects or to illustrate drainage in a variety of situations such as parking lot paving.  
         [0016]    In FIG. 1, optional radial lasers are provided at  150 ,  152 ,  154  and  156  to provide radially projected laser light that results in corresponding visible lines  250 ,  252 ,  254  and  256  on the surface as shown in FIG. 2. The radial lasers may be gimbal mounted, or comprise one or more mirrors that move and reflect laser light as desired to produce the patterns, or otherwise configured to produce the desired patterns.  
         [0017]    A level  160  is mounted at the top of the projector  100 , and provides the ability to either manually adjust the tripod legs to obtain a tower that is plum, or may be computer controlled and coupled to the laser sections to adjust the angles of the lasers to ensure that the proper pattern is projected. A handle  170  is optionally provided for convenient carrying.  
         [0018]    In one embodiment, the projector  100  is supported above a golf green  310  in FIGS. 3 and 4 that has a varying slope to it. While the projector is effectively upright, following a line toward the center of gravity of the earth, the green is not necessarily perpendicular throughout its surface, resulting in the varying slope. The slope is exaggerated in FIG. 3 for illustration purposes. A broken line  315  is used to show the profile of a perfectly flat green. Each of the laser sections projects laser light in a downward cone as previously described with radii that are equally increasing. The equal increase can be seen where each projection intersects the broken line  315 . As the projection continues to the actual green  310 , the resulting reflection of the lasers produces successive arcs  325 ,  330 ,  335 ,  340 ,  345 ,  350  and  355  with radii that do not increase equally as measured following the contour of the green. Instead, it produces a pattern that is similar to that of a contour relief map.  
         [0019]    As illustrated in FIGS. 3 and 4, the green slopes down initially from the projector or golf hole, and then toward the far left, it slopes back up, toward broken line  315 . The arcs are initially separated by about the same amount as they are on the broken line  315 , but then the distance between successive arc increases where the green is sloping away from the projector, as apparent between arcs  340 ,  345  and  350 . As the green slopes back up, the distance between the arcs decreases, and in fact appear closer than would appear on a flat surface. This variation in distance between arcs provides a good visual indication of the slope of the green, useful in training a golfer to read greens. However, the unlike a true contour map which uses closely spaced lines for changes in altitude, the pattern produced is contour like, in that altitude changes are illustrated either by further spaced lines, or closely spaced lines depending on whether the green is sloping uphill away from the projector, or downhill, away from the projector. Optionally, the radial lines produced by the radial lasers provide further illustration of the break or slope of the green.  
         [0020]    In one embodiment, each of the laser sections fully rotates 360 degrees at approximately 600 rpm to provide arcs that are generally visible to humans. In a further embodiment, mirrors are angled back and forth to provide a partial circle or arc of a desired angle. In yet a further embodiment, all lasers are movably mounted in an single rotating section. Calibration of the lasers to provide a desired pattern may be performed on a flat surface using a tape measure, and varying the angles of the lasers to produce desired spacing on the surface. In yet a further embodiment, all lasers are mounted on computer controlled servos, and the level may also be computer controlled as represented at  160 . An I/O panel is provided, also represented at  160  to input parameters R, x, and a height of the projector. The computer calculates the proper angles for the lasers and moves them via the computer controlled servos. In yet a further embodiment, all laser angles are fixed, and the height of the projector is adjusted to a predetermined height to provide a desired pattern. In still a further embodiment, the height of the projector is sensed, such as by laser or sonic distance sensing.  
         [0021]    In one embodiment, the color of the laser light is selected to provide sufficient illumination of a golf green in sunlight. In a further embodiment, glasses are provided to filter ambient light, enhancing the viewability of the laser light reflecting off the greens.