Abstract:
A handheld device is adapted to perform non-contact measurements to determine distances, angles, arc lengths and radii between select points on physical structures. The device is assembled and contained within a handheld, portable housing and includes various control and input keys, a visual display and three laser components. Each laser component includes a laser emitter including a laser emitter diode with an associated emitter lens. The laser emitters of the three laser components are set at fixed, predetermined angles relative to one another at the front end of the housing. Each laser component also includes a laser receiver with an associated detector lens correspondingly positioned in alignment with the emitter lens. The laser components are adapted to emit and receive light signals to collect image data representative of a straight line distance between a predetermined set point within the device and a point on the surface of the measured structure. A processing unit receives the image data from the three laser components to determine straight-line distance measurements. These measurements are used in conjunction with known angles between the three laser emitters to perform calculations that determine distance, angle, arc length and radius of the physical structures.

Description:
[0001]     This application is based on provisional patent application serial No. 60/717,123 filed on Sep. 14, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to non-contact measuring devices and, more particularly, to a handheld measurement device that uses laser emitter/receiver components and a computer processing unit to perform calculations of distance, angle, arc length and/or the radius between two points.  
         [0004]     2. Discussion of the Related Art  
         [0005]     Non-contact measurement devices for quickly and accurately obtaining straight-line distance and angle measurements are well known in the related art. These devices typically use one or more light generating components which emit a light signal or pulse through a lens and onto a surface of a structure associated with the desired measurement. Light energy returns from the surface and through the same detector lens or a separate lens. The data collected from the light pulse transmission and return (i.e. receipt) is used to determine straight-line distance, usually based on elapsed time between light pulse transmission and receipt.  
         [0006]     Examples of non-contact distance measurement devices are found in U.S. Patents to Ehbets et al., U.S. Pat. No. 5,949,531; Gaechter, U.S. Pat. No. 5,892,576; Hinderling et al., U.S. Pat. No. 6,411,371; and Hertzman et al., U.S. Pat. No. 6,115,112.  
         [0007]     Examples of non-contact measurement devices which determine both straight-line distance and angles between two points are found in the U.S. Patents to Pease, U.S. Pat. Nos. 6,593,587, 6,858,857, and 6,858,858.  
         [0008]     An example of a non-contact measurement device that determines diameter and radius is found in the U.S. Patent to Gelbart, U.S. Pat. No. 5,291,273. The device in Gelbart is not a handheld device, but uses light emitting devices to project two beams of light through a lens. One beam of light is directed to the center of the object being measured and the other beam is directed at a fixed distance from the first beam. The beams reflect off of the object and the angle between the reflected beams is used to determine the radius.  
         [0009]     Despite the extensive knowledge and developments in the art of non-contact measurement using one or more light emitter/receiver devices, there remains an urgent need for a single handheld, compact device which performs non-contact measurements to determine straight-line distance, angle, arc length and/or the radius of a physical structure.  
       OBJECTS AND ADVANTAGES OF THE INVENTION  
       [0010]     With the foregoing in mind, it is a primary object of the present invention to provide a handheld, portable non-contact measuring device which quickly and accurately determines distance, angle, arc length and radius of a physical structure.  
         [0011]     It is a further object of the present invention to provide a handheld non-contact measurement device which is adapted to determine straight-line distance between either the front end or back end of the device and a particular point on a physical structure.  
         [0012]     It is still a further object of the present invention to provide a handheld non-contact measurement device which is adapted to determine straight-line distance between two points remote from the device, such as the vertical wall height between the floor and ceiling in a building structure.  
         [0013]     It is yet a further object of the present invention to provide a handheld non-contact measurement device which is adapted to measure and indicate both inside angles (i.e. less than 180°) between two surfaces and outside angles (greater than 180°) between two surfaces.  
         [0014]     It is still a further object of the present invention to provide a handheld non-contact measurement device which quickly and accurately determines the total length of an arch between two points on a surface, the radius of the arc, the total span of the arc and the distance between the center of the span of the arc and the center of the length of the arc.  
         [0015]     It is yet a further object of the present invention to provide a handheld non-contact measurement device which quickly and accurately determines the area of a circle and the volume of a cylinder.  
       SUMMARY OF THE INVENTION  
       [0016]     The present invention is directed to a handheld device that is adapted to perform non-contact measurement to determine distances, angles, arc lengths and radii between select points on physical structures. The device is assembled and contained within a handheld, portable housing and includes various control and input keys, a visual display and three laser components. Each laser component includes a laser emitter including a laser emitter diode with an associated emitter lens. The laser emitters of the three laser components are set at fixed, predetermined angles relative to one another at the front end of the housing. Each laser component also includes a laser receiver with an associated detector lens correspondingly positioned in alignment with the emitter lens. The laser components are adapted to emit and receive light signals to collect image data representative of a straight line distance between a predetermined set point within the device and a point on the surface of the measured structure. A processing unit receives the image data from the three laser components to determine straight line distance measurements. These measurements are used in conjunction with known angles between the three laser emitters to perform calculations that determine distance, angle, arc length and radius of the physical structures.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     For a fuller understanding of the nature of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:  
         [0018]      FIG. 1  is a top plan view of the handheld non-contact measurement device, in accordance with a preferred embodiment of the present invention, illustrating an arrangement of control and input elements or keys, and a visual display;  
         [0019]      FIG. 2  is a general schematic diagram showing the primary internal components of the non-contact measurement device of  FIG. 1 ;  
         [0020]      FIG. 3  is a flow diagram of the distance measuring operation of the device;  
         [0021]      FIG. 4  is a general plan view illustrating various methods to measure straight-line distance between two points using the non-contact measurement device of the present invention;  
         [0022]      FIG. 5  is a flow diagram of the angle measuring operation performed by the non-contact measurement device of the present invention;  
         [0023]      FIG. 6A  is a general diagram illustrating use of the non-contact measurement device to measure an inside corner between two wall surfaces;  
         [0024]      FIG. 6B  is a general diagram illustrating use of the non-contact measurement device to measure an outside corner angle between two adjacent wall surfaces;  
         [0025]      FIG. 7  is a flow diagram of the radius measuring operation performed by the non-contact measurement device of the present invention;  
         [0026]      FIG. 8A  is a general diagram illustrating use of the non-contact measurement device to determine the inside radius of a concave surface, as well as the arc length between two points of the surface, the total span of the arc, the straight-line distance between two points along the concave surface and the distance between the imaginary line between the two points on the arc and the center of the arc segment between the two points; and  
         [0027]      FIG. 8B  is a general diagram illustrating use of the non-contact measurement device to determine the outside radius of a convex surface as well as the total arc length, the span of the arc, the straight-line distance between the two points along the arc and the distance between the imaginary line between the two points on the arc and the center of the arc segment between the two points. 
     
    
       [0028]     Like reference numerals refer to like parts throughout the several views of the drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]     The present invention is directed to a portable, handheld non-contact measuring device and is generally indicated as  100  throughout the drawings. The electronic components of the device are contained within a housing  110 , as generally illustrated in  FIGS. 1 and 2 . In a preferred embodiment, the top face  112  of the housing  110  presents an arrangement of control and input elements or keys (labeled  1 - 21 ) and a visual display  114  such as an LCD panel.  
         [0030]     The device uses 3 laser emitter/receiver components labeled A- 1 , A- 2 , and A- 3 . These 3 laser emitter/receiver components are set within the front end  130  of the housing  110  at fixed, predetermined angles relative to one another. Each laser emitter/receiver component includes an associated laser emitter diode  120  for generating a laser light signal and a laser receiver  122  for receiving a returning light signal. Each laser emitter/receiver component A- 1 , A- 2  and A- 3  further includes an associated emitter lens  124  and detector lens  126  on the front end  130  of the housing  110 .  
         [0031]     On the display  114 , a centering indicator B directs the user to move the handheld device  100  to the left or to the right in order to find the center of an angle when measuring an angle between two surfaces, or to find the optimal position for radius measurement. The C function symbol on the display indicates the type of measurement being performed (e.g. distance, area, angle, radius, etc). The indicator labeled as D on the display lists recent measurements that have been taken such as linear, area, angle, radius, etc. Using the scroll keys  13  and  17 , the user can go back or forward through a list of previously acquired measurements. The display function labeled E shows a current measurement or the sum of two or more saved measurements.  
         [0032]     A processor  140  in the housing receives all control commands that are entered by depressing the numerous control keys, and is programmed to perform all measurement calculations based on data received from the return laser light signals. The processor  140  is also programmed to change modes in response to mode control commands entered with the control keys. The processor  140  communicates with all three laser emitter/receiver components A- 1 , A- 2  and A- 3  to control generation, emission and receipt of laser light signals, and the processor  140  controls operational functions of the display  114 , including transmission of function, mode and measurement data for visual presentation on the display  114 .  
         [0033]     The control elements or keys on the device are shown in  FIG. 1 . In particular, power key  1  is used to energize (turn on) and de-energize (turn off) the device. Control key  2  is pressed once for targeting and twice for measuring. Control key  3  operates a backlight on the display  114  for ease of reading the display in low ambient light level conditions. Control key  4  operates a scan mode for continuous beams to find minimum or maximum linear, center angle or optimal radial placement. Control key  5  allows the operator to change modes of operation of the device or to change other control elements/keys to different operation modes. Control key  6  is used to set linear measurement mode. Control key  7  is used to set area measurement mode. Control key  8  operates the cubic volume measurement mode.  
         [0034]     When it is desired to determine the straight-line distance between two points, both of which are remote from the device, the device can be changed to a Pythagorean mode using control key  9 . For instance, the Pythagorean mode can be used to determine the distance between the base and top of a structure, thereby providing a height measurement. Control key  10  is pressed once to obtain a full angle measurement of a corner formed by two adjacent wall surfaces. Pressing the mode control key  5  and the angle measurement control key  10  provides a measurement for a ½ angle. The mode key  5  can also be used to switch between decimal, degree-minute-second or radian measurement.  
         [0035]     When determining the miter or bevel angles of crown moulding, it is necessary to first input the spring angle of the crown moulding using input spring key  12 . The bevel/miter control key  12  is used to indicate the miter and bevel angles of, for instance, crown moulding and base board trim.  
         [0036]     As previously discussed, control keys  13  and  17  provide for a scroll-up and scroll-down function for indicators on the display.  
         [0037]     Control key  14  is pressed once for determining radius measurement. Pressing control key  14  twice provides for diameter measurement. Pressing the mode key  5  simultaneously with control key  14  allows the user to input span (run) of an arc. This allows for a distance measurement of the span to determine the running length of the arc.  
         [0038]     Control key  15  is pressed once when measuring the area of a circle and twice to determine the volume of a cylinder. Control key  16  is used in conjunction with mode key  5  to change between measurement units such as decimal feet, feet and inches, and metric units. Control key  18  allows the user to add a current measurement to memory. Control key  19  subtracts a current measurement from memory. Control key  20  is used to recall the sum total of all measurements in memory. Control key  21  allows the user to clear the memory.  
         [0039]     While not shown, the device provides for a USB or Bluetooth connection, allowing the user to download measurement information to a computer or PDA. Also, the bottom end of the housing is provided with a tripod mount for vertical measurements.  
         [0040]      FIG. 3  illustrates the sequence of operation of the non-contact measurement device  100  to measure straight-line distance. The straight-line distance measurement may be taken from the front end of the housing of the device to a point on a surface, the rear end of the housing to a point on the surface or, alternatively, the measurement can be made between two remote points on a surface.  
         [0041]      FIG. 4  illustrates the three different linear measurement operations. For instance, the user can hold the front end of the device at an inside corner of a wall surface and direct the laser beam to an adjacent wall surface at the opposite end of the wall to determine the length of wall  50 . On the other hand, if it is desired to determine the length of wall  52  which spans between walls  50  and  54 , the user would place the back end of the device  100  against wall surface  54  and direct the laser beam onto the surface of wall  50 . By selecting the mode of operation for measurement from the back end of the housing, the distance between the back end of the housing  110  of the device  100  and the wall surface  50  is measured, thereby indicating the length of wall  52  that spans between walls  50  and  54 .  
         [0042]     Another mode of straight-line distance measurement is shown in  FIG. 4 , wherein it is desired to measure between two points on a wall surface. This mode, known as the Pythagorean mode, requires the formation of a right angle triangle. This is achieved by directing one laser beam  64  from the device at an angle which is perpendicular (90°) to a point on the surface of the wall  56 . The second straight-line distance measurement can be made by directing laser beam  66  at an angle towards the corner of the walls  56 ,  58 , forming the hypotenuse of the right triangle. As seen in  FIG. 4 , a right triangle is formed by the two laser beam paths  64 ,  66  and wall surface  56 . The distance between point  60  and point  62  on wall surface  56  can be determined using the Pythagorean Theorem. Specifically, the device of the present invention is able to measure the distance of legs  64  and  66  of the formed triangle. Having the measured distance of these two legs of the right triangle, the third leg of the triangle, between points  60 ,  62  on wall surface  56  is easily calculated by the processing unit of the device using the Pythagorean Theorem (i.e. a 2 +b 2 =c 2 ). The distance between point  60  and  62  on wall surface  56  is then displayed next to indicator E of the visual display.  
         [0043]      FIG. 5  shows a flow diagram depicting the angle measuring operation performed by the non-contact measurement device  100 . As seen in  FIGS. 6A and 6B , the device can be used to measure both the inside corner angle (i.e. less than 180°) as well as an outside corner angle (i.e. greater than 180°).  
         [0044]     Referring to  FIGS. 5 and 6 A- 6 B, the angle measurement functions are performed as follows:  
         [0045]     In the diagrams of  6 A and  6 B, the reference indictors have the following meanings: 
        “x”=point of convergence of beams “A 1 ”, “A 2 ”, and “A 3 ”.     “β”=full angle of target.     “λ”=half angle of target.     “θ”=angle between center beam (A 2 ) and either one of side beams (A 1  or A 3 ).     “σ”=Spring Angle. (i.e. angle from wall to back of crown molding.)        
 
         [0051]     Referring to  FIGS. 5 and 6 A- 6 B, the angle measurement functions are performed as follows:  
         [0052]     Beams “A 1 ”, “A 2 ” and “A 3 ” are set at fixed angles from each other (θ). The processing unit is programmed to “know” that the three beams are set at fixed angles relative to each other. Additionally, the processing unit is programmed to “know” at which point beams “A 1 ”, “A 2 ”, and “A 3 ” would converge (x) within the device (i.e. behind the laser components A- 1 , A- 2  and A- 3 ). To begin an angle measurement, the user targets the center of the angle with beam “A 2 ”. The device emits beams in sequence so as not to receive confusing readings from other beams. The display indicates in which direction to move the device until beams “A 1 ” and “A 3 ” are equidistant. Once properly centered, the device can perform the following functions:  
         [0053]     a) Determine the distance from point “x” to points targeted by beams “A 1 ”, “A 2 ”, and “A 3 ”.  
         [0054]     b) Find the length of side “s” using: s 2 =“A 1 ”  2 +” A 2 ”  2 −2” A 1 ”” A 2 ” cos” “θ” 
         [0055]     c) Find the angle “β” using: β=2λ 
           cos   ⁢           ⁢   λ     =         “     A   ⁢           ⁢   1     ”     2     -     (       s   2     +       “     A   ⁢           ⁢   2     ”     2       )             -   2     ⁢     (     s   ⁢     “     A   ⁢           ⁢   2     ”       )           
       λ   =       cos     -   1       ⁡     (     cos   ⁢           ⁢   λ     )           
 
         [0056]     d) If cos λ is a negative value the device will indicate that “β” is an outside angle. If cos λ is a positive value the device will indicate that “β” is an inside angle.  
         [0057]     If the spring angle (“σ”) has been input or recalled from memory, then the device can calculate miter and bevel settings for crown moulding or many other applications requiring a compound angle. To obtain miter setting only, as with base mouldings or other flat materials, input “0” as spring angle. Use following to obtain desired values:  
                 a   )     ⁢           ⁢   Miter     =       tan     -   1       ⁡     (         tan   ⁡     (     180   -   β     )       ⁢   cos   ⁢           ⁢   σ     2     )                       b   )     ⁢           ⁢   Bevel     =       sin     -   1       ⁡     (         sin   ⁡     (     180   -   β     )       ⁢   cos   ⁢           ⁢   σ     2     )                 
 
         [0058]     The radius measuring operation of the device is generally depicted in the flow diagram of  FIG. 7 .  FIGS. 8A and 8B  illustrate measurement of radius, arc length, arc span and other measurements of both an inside radius or concave surface ( FIG. 8A ) and an outside radius for convex surface (FIG.  8 B). In referring to  FIGS. 8A and 8B , the symbols shown therein have the following meaning:  
         [0059]     “θ”=angle between center beam (A 2 ) and either one of side beams (A 1  or A 3 ).  
         [0060]     “Ψ”=angle formed by radii originating from center of circle and reaching extreme points of span of arc (s).  
         [0061]     “l”=total length of arc  
         [0062]     “r”=radius of arc.  
         [0063]     “s”=total span (run) of arc.  
         [0064]     “t”=point at which Beam “A 2 ” intersects line “A 1 ”, “A 3 ”.  
         [0065]     “w”=distance of imaginary line between points targeted by beams “A 1 ” and “A 3 ”.  
         [0066]     “x”=point of convergence of beams “A 1 ”, “A 2 ” and “A 3 ”.  
         [0067]     “y”=distance from point of intersection of beam “A 2 ” with imaginary line that spans between the arc from the points of beams A 1  and A 3  on the arc to point where Beam “A 2 ” hits the target on the arc.  
         [0068]     “z”=distance from point of convergence (x) to above-mentioned intersection (β).  
         [0069]     In operation, Beams “A 1 ” and “A 3 ” are set at a fixed angle off center beam “A 2 ”. The processing unit is programmed to “know” the angle at which the beams are set. The processing unit is programmed to “know” the point at which beams “A 1 ”, “A 2 ”, and “A 3 ” would converge (x). To begin, the user targets an arc or circle section with the center beam A 2 . The device emits beams in sequence so as not to receive confusing readings from other beams. The display indicates in which direction to move device until beams “A 1 ” and “A 3 ” are equidistant. Once properly aligned, the device can perform the following functions:  
         [0070]     a) Determine the distance from point “x” to points targeted by beams “A 1 ”, “A 2 ” and “A 3 ”.  
         [0071]     b) Determine distance “w” using the following formula: w+2 sin θ “A 1 ” 
         [0072]     c) Determine distance “y” using the following formula: y=“A 2 ”−z  
         [0073]     d) Determine distance “z” using the following formula: z=“A 1 ”/secθ 
         [0074]     e) Using the above information, the device can determine the radius of the arc using the following formula: r=(w 2 /8y)+y/2 
        (If “y” is a negative value, the device will determine the target surface to be an outside radius, store that determination to memory and convert “y” to a positive value.)        
 
         [0076]     f) The Device displays radius and indicates whether it is an inside or outside radius.  
         [0077]     g) With user input, direct linear measurement or the Pythagorean (indirect) measurement function, the device can determine the total span of an arc or circle.  
         [0078]     h) Determine “Ψ” using:  
         sin   ⁢           ⁢   Ψ     =       w   ⁢     /     ⁢   2       “     A   ⁢           ⁢   1     ”           
 
         [0079]     i) Convert “Ψ” from degrees to radians.  
         [0080]     j) With input of total span of arc or circle, the device can determine total length of arc (“l”) using: l=rΨ R  
 
OR 
        Determine the circumference (“C”) of a circle using common formula: πd (where π=3.14 and d is the diameter)        
 
         [0082]     k) In the “Area” mode, the device can determine the area of a circle using the well known formula: πr 2  (where π=3.14 and r is the radius)  
         [0083]     l) In the “Volume” mode, the device can determine the volume of a cylinder by adding the height measurement in the well known formula: hπr 2    
         [0084]     While the invention has been shown and described in accordance with a preferred and practical embodiment thereof, it is recognized that departures from the instant disclosure are fully contemplated within the spirit and scope of the invention which is not to be limited except as defined in the following claims as interpreted under the doctrine of equivalents.