TECHNICAL FIELD

[0001] This invention relates to the field of distance measurement, in general, and more specifically to a laser distance measurement apparatus.

BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application .

[0003] Retractable tape measures are well-known devices used to measure distances. A retractable tape measure generally consists of a ribbon of cloth, plastic, fibre glass, or metal with linear-measurement markings coiled on a spool inside a case, often with a spring return mechanism for coiling the tape measure onto the spool. It is a common measuring tool and its design allows for a measure of great length to be easily carried in pocket or toolkit and permits one to measure around curves or corners. Due to the ubiquitous use of retractable tape measures, a number of improvements have been proposed to such devices over the years.

[0004] Some of these improvements include a laser line generator to assist a user in measuring and marking (see, for example, US 7,299,565), a light plane generator to facilitate measuring of surfaces (as per US 7,024,791), and the like. [0005] The Inventor has identified a need in the art of tape measures for a device which is able to measure a distance between objects that are not always easily-reachable or readily accessible. For example, it is sometimes necessary to record a distance measurement between objects that are hard to reach with a conventional tape measure, or objects that are dangerous to approach, or the like.

[0006] The current invention was conceived with this need in mind.

SUMMARY OF THE INVENTION

[0007] The skilled addressee will appreciate that reference herein to a tape measure generally refers to a retractable tape measure having a stiff, curved (often metallic) ribbon that can remain substantially stiff and straight when extended, but retracts into a coil for convenient storage, typically having a floating tang or hook on the end of said ribbon to aid measuring. However, variations hereon are possible and within the scope of the present invention, where appropriate. Accordingly, reference herein to a tang of a measuring tape generally refers to a starting point or starting end of a tape ribbon thereof.

[0008] According to a first aspect of the invention there is provided laser distance measurement apparatus comprising: a housing defining a seat for operatively receiving a tape measure;

a first laser emitter operatively fast with the housing and configured to selectively emit a first laser beam substantially perpendicular to a length of tape of said tape measure when extended; and

a second laser emitter operatively fast with a tang of the tape and configured to selectively emit a second laser beam substantially perpendicular to the length of tape, wherein said first and second laser beams are visually projectable onto respective remote points and a distance between said points is remotely obtainable via the tape measure.

[0009] In one embodiment, the apparatus comprises a processor configured to detect, via a suitable sensor, a length of tape extended from the housing, said apparatus further including a display configured to display such detected extension .

[0010] Typically, the suitable sensor comprises an optical and/or magnetic sensor configured to sense distance markings on the tape as said tape is extended or retracted.

[0011] Typically, the display includes a light-emitting diode (LED) display, a liquid crystal display (LCD) , an e-ink display, or the like.

[0012] Typically, the housing is dimensioned to define a specific length and includes distance markings thereon to facilitate distance measurement in combination with the tape.

[0013] In an embodiment, the housing includes a spirit level .

[0014] Typically, the first and second laser emitters are configured by means of suitable proximity switches to automatically emit the laser beams when the tape is extended from the housing, and to deactivate once the tape is fully retracted into said housing.

[0015] Typically, the housing includes a magnet configured to secure the apparatus to a magnetic surface to facilitate in distance measurement.

[0016] Typically, the processor is configured to measure a distance by means of said laser beam time-of-flight from the first and/or second laser emitter.

[0017] In an embodiment, the first and/or second laser emitter is configured to swivel on the housing and/or tang, respectively, in order to emit a laser beam(s) radially from the length of tape

[0018] In one embodiment, the first and/or second laser emitter is configured to swivel on the housing and/or tang, respectively, in order to emit a laser beam(s) at a predetermined angle from the perpendicular to the length of tape .

[0019] In one embodiment, the first and/or second laser emitter is configured to emit the first and/or second laser beam, respectively, at an angle from the perpendicular to the length of tape.

[0020] In one embodiment, the processor is configured to detect the angle from the perpendicular of the first and/or second laser emitters. [0021] In one embodiment, the processor is configured to calculate and display distance measured according to the following equation, or derivatives thereof:

Y = D + Z. tan a

where :

Y = total distance measured;

D = distance measured on tape measure;

Z = distance measured from laser beam time-of-flight ; and = angle from the perpendicular of the laser beam.

[0022] In an embodiment, the apparatus includes a button configured to capture, display, store and/or transmit a distance measured on the tape measure so that an operator is able to view such measured distance at a later stage after measurement .

BRIEF DESCRIPTION OF THE DRAWINGS

The description will be made with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic perspective view representation of an embodiment of a laser distance measurement apparatus, in accordance with an aspect of the present invention;

Figure 2 is a diagrammatic perspective view representation of the laser distance measurement apparatus of Figure 1, showing swivelable laser emitters;

Figure 3 is a diagrammatic side view representation of an embodiment of the laser distance measurement apparatus of Figure 1, showing a processor thereof; Figure 4 shows diagrammatic representations of manners in which embodiments of the laser distance measurement apparatus of Figure 1 are useable to measure remote distance; and

Figure 5 shows further diagrammatic representations of manners in which embodiments of the laser distance measurement apparatus of Figure 1 are useable to measure remote distance, particularly where laser beams are emitted at an angle from the perpendicular of the measuring tape.

DETAILED DESCRIPTION OF EMBODIMENTS

[0023] Further features of the present invention are more fully described in the following description of several non limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention to the skilled addressee. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. In the figures, incorporated to illustrate features of the example embodiment or embodiments, like reference numerals are used to identify like parts throughout.

[0024] With reference now to the accompanying drawings, there is broadly exemplified one embodiment of a laser distance measurement apparatus 10, as described above. Apparatus 10 generally comprises a housing 16 which defines a seat 18 for operatively receiving a tape measure 8, as shown. Apparatus 10 can thus be provided inclusive or exclusive of tape measure 8. Where apparatus is provided exclusive of tape measure 8, a user may provide their own tape measure for placement onto seat 18, into the housing 16, or the like. [0025] Tape measure 8 is generally of the retractable type having a stiff, curved (often metallic) ribbon or tape 12 that can remain substantially stiff and straight when extended, but retracts into a coil for convenient storage, typically having a floating tang or hook 14 on the end of said ribbon 12 to aid measuring .

[0026] Apparatus 10 further includes a first laser emitter 20 which is operatively fast with the housing 16 and is configured to selectively emit a first laser beam 22 substantially perpendicular to a length of tape 12 of said tape measure 8. First laser emitter 20 is generally positioned on the housing 16 in order to emit laser beam 22 at right angles to the tape 12, as shown.

[0027] Apparatus 10 further includes a second laser emitter 24 which is operatively fast with tang or hook 14 of the tape 12 and is also configured to selectively emit a second laser beam 26 substantially perpendicular to the length of tape 12.

[0028] By means of this configuration of apparatus 10, the first and second laser beams 22 and 26 are visually projectable onto respective remote points 28, as shown in Figure 4A, and a distance Y between said points is obtainable via the tape measure 8 as the first and second laser beams 22 and 26 are substantially parallel to each other.

[0029] The skilled addressee is to appreciate that apparatus 10 does not necessarily allow exact or precise measurement of remote distance, but depending on requirements, allows sufficient accuracy to be generally useful. For example, tape 12 generally needs to be extended parallel to the distance Y to be measured, i.e. between points 28, otherwise parallax errors may occur. However, in many applications such remote distance measurement provides adequate accuracy, e.g. measurement of furniture, or the like.

[0030] In one embodiment, the apparatus 10 comprises a processor 30 configured to detect, via a suitable sensor, a length of tape extended from the housing 16, the apparatus 10 further including a display 32 configured to display such detected extension. The suitable sensor (not shown) typically comprises an optical and/or magnetic sensor configured to sense distance markings on the tape 12 as said tape is extended or retracted. Such sensors are known in the art and will not be described in detail.

[0031] The display 32 may include a light-emitting diode (LED) display, a liquid crystal display (LCD) , an e-ink display, or the like. Similarly, the processor 30 typically comprises an integrated circuit microprocessor, as is known in the art .

[0032] The apparatus 10 may also include a button configured to capture, display, store and/or transmit (typically via processor 30) a distance measured on the tape measure so that an operator is able to view such measured distance at a later stage after measurement.

[0033] Typically, the first and/or second laser emitter 20, 24 is configured to swivel on the housing 16 and/or tang 14, respectively, as shown in Figure 2. Such swivelling enables laser beam emission radially to the tape measure, in general, to facilitate measurement of distances above or below a user, or the like. In an embodiment, the first and second laser emitters 20, 24 are configured by means of suitable proximity switches (not shown) to automatically emit the laser beams 22, 26 when the tape 12 is extended from the housing 16, and to deactivate once the tape is fully retracted into said housing 16. For example, a suitable reed switch can be used so that, when the second emitter 24 is moved from the housing 16, the laser emitters 20, 24 activate, or the like. Similarly, an optical or magnetic sensor of the processor 30 may sense tape extraction and activate the laser emitters 20, 24, or the like. Other configurations are possible in within the scope of the present invention.

[ 0034 ] The housing 16 is typically dimensioned to define a specific length and includes distance markings 34 thereon to facilitate distance measurement in combination with the tape measure 8. In one embodiment, the housing 16 includes a spirit level 36, and may also include a magnet (not shown) configured to secure the apparatus 10 to a magnetic surface to facilitate in distance measurement. Similarly, the housing 16 may include other attachment means, such as a hook, a suction mechanism, or the like, as will be appreciated by the skilled addressee.

[ 0035 ] In a more advanced embodiment, as exemplified in Figure 4B, the processor 30 is configured to measure a distance by means of laser beam time-of-flight from the first and/or second laser emitter 20, 24, as is known in the art of laser range finding. In such an embodiment, the first and/or second laser emitter 20, 24 is typically configured to emit the first and/or second laser beam 22, 26, respectively, at an angle from the perpendicular to the length of tape, as shown. The processor 30 is then typically configured to detect the angle from the perpendicular of the first and/or second laser emitters 20, 24. [0036] For example, either laser emitter 20, 24 may be configured to pivot to define angle a, with the processor 30 configured to detect angle a. A simple embodiment could see the first or second laser emitter 20, 24 pivotable to a known angle a, i.e. when pivoted into place, a switch is activated and the processor 30 detects such switch activation which is pre-programmed, or even a secondary laser beam (not shown) may be transmissible by either first or second laser emitter 20, 24, at a predetermined angle, or the like. In a more advanced version, the processor 30 may be configured to detect via a suitable detector at what angle a laser beam 22, 26 is emitted, or the like, i.e. via a suitably configured angle sensor, etc. For example, each laser beam 22, 26 may be emitted at respective angles oil and cx2, or the like, with processor 30 configured to detect such angles oil and OL2.

[0037] In such an embodiment, the processor 30 can be configured to calculate and display distance measured, as per Figure 4B, according to the following equation, or via derivatives thereof:

Y = D + Z. tan a

where :

Y total distance measured;

D distance measured on tape measure;

Z distance measured from laser beam time-of-flight ; and a angle from the perpendicular of the laser beam.

[0038] In this manner, distance to be measured Y is determinable according to measured distance D, representing XI, and X2 is determinable via measured distance Z (via laser beam time-of-flight ) and angle a, as is known in the art. [0039] Similarly, with reference to Figures 5, the processor 30 can be configured to measure two angles oil and 02, one per emitted laser beam 22, 26, along with respective distances Z1 and Z2 via laser beams time-of-flight , in order to calculate a measured distance, or the like. Such an embodiment may address parallax errors in measurements, depending on requirements. Processor 30 may also be configured to measure angles of laser beams 22, 26 relative to a horizontal plane, or the like.

[0040] Examples of such embodiments measuring various distance based on laser angles and respective beam time-of- flights are represented in Figures 5. As will be readily apparent to the skilled addressee, the various relationships between measured distances and angles are governed by basic trigonometric principles and will not be described in detail.

[0041] Applicant believes is particularly advantageous that the present invention provides for a means of measuring distance remotely, as well as distance at different depths or planes .

[0042] Optional embodiments of the present invention may also be said to broadly consist in the parts, elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts, elements or features, and wherein specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. In the example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail, as such will be readily understood by the skilled addressee .

[ 0043 ] The use of the terms "a", "an", "said", "the", and/or similar referents in the context of describing various embodiments (especially in the context of the claimed subject matter) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including, " and "containing" are to be construed as open- ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. No language in the specification should be construed as indicating any non-claimed subject matter as essential to the practice of the claimed subject matter .

[ 0044 ] Spatially relative terms, such as "inner," "outer," "beneath, " "below, " "lower, " "above, " "upper, " and the like, may be used herein for ease of description to describe one element or feature's relationship to another element (s) or feature (s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. [0045] It is to be appreciated that reference to "one example" or "an example" of the invention, or similar exemplary language (e.g., "such as") herein, is not made in an exclusive sense. Various substantially and specifically practical and useful exemplary embodiments of the claimed subject matter are described herein, textually and/or graphically, for carrying out the claimed subject matter.

[0046] Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example. These examples are intended to assist the skilled person in performing the invention and are not intended to limit the overall scope of the invention in any way unless the context clearly indicates otherwise. Variations (e.g. modifications and/or enhancements) of one or more embodiments described herein might become apparent to those of ordinary skill in the art upon reading this application. The inventor (s) expects skilled artisans to employ such variations as appropriate, and the inventor (s) intends for the claimed subject matter to be practiced other than as specifically described herein.

[0047] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.