fig1 and 5 show a laser putting cup 1 in accord with this invention . the putting cup 1 has main body member 2 which defines a central circular golf hole 3 into which a golf ball 4 is to be rolled up from a slanted ramp 5 by a putter or otherwise propelled by another type of golf club . the hole 3 has a 4 . 25 inch diameter , which is consistent with the official rules of golf , and an entrance side 6 at which golf balls are aimed and putted . support bracket means , such as mounting fixture 7 , is attached to body member 2 adjacent the back or opposite side 8 of hole 3 . a circular opening or bore 9 extends completely through fixture 7 , and bore 9 is centered adjacent side 8 essentially diametrically opposite to the center of hole entrance side 6 . bore 9 may have a diameter of five - eights inch , and the bore is angled downwardly at a small angle , such as 1 . 5 degrees . fixture 7 may be either an integral or molded part of body member 2 or may be a separate part attached to the cup body member , which may be made from metal , plastic or wood . a right circular cylindrical tube 11 has one end 12 that extends into bore 9 where the tube is firmly secured to fixture 7 . an opposite end 14 of tube 11 protrudes from fixture 7 . means for producing a visible beam of laser light , such as a handheld laser pointer 15 , is insertable into and removable from end 14 of the tube . tube 11 is dimensioned such that slipping the laser pointer 15 into an interference fit with the tube diameter positions the laser on - axis for correct beam projection , and also this serves to actuate an on - off switch 16 which is depressed inwardly by the inside surface of the tube . activation of the laser projects a beam 17 of laser light diametrically across the center of hole 3 on to and across an adjacent surface 18 , such as a rug or putting green . pointer 15 is rotatable within tube 11 . the laser beam can have any visible wavelength . for example , a 650 nm wavelength , 5 mw laser diode device would be very bright and would conform to fda approved standards for a class illa laser . such a laser is commercially available as the hl 106 laser pointer , which is powered by two small n - type 1 . 5 v batteries . tube 11 should be a non - abrasive plastic , such as nylon or delrin , to avoid scratching the laser pointer 15 . the width of the laser light beam 17 should be adjustable to enhance or maximize the size or length of the beam that is visible on the surface 18 and on a wall 20 or the face or top of a putter or other type of golf club . the means for changing the width of the beam 17 may include means that can diffuse the beam , such as a lens 21 that has been fixedly attached inside of tube 11 adjacent end 12 . lens 21 may be a section of a right circular cylinder that is shaped like a circular disk , as shown in fig1 and 2 . or the lens may have other shapes , such as the rectangular shape of lens 22 shown in fig3 and 4 . the beam 17 of laser light could be diffused by passing it first through either the flat side 23 or the curved side 24 . or the sides 23 and 24 of the lens could both be curved , and the curves could be either convex or concave , or a mixture concave and convex sides could be used . the width of beam 17 may also be changed by diffusing the beam with a cylindrical mirror , as for example by silvering the side 24 of lens 22 and orienting the laser pointer 15 so that the beam reflects from side 24 at an angle , such as forty - five degrees , and the beam 17 would then be then projected as shown . the geometry of the projected beam 17 is shown in fig5 where a laser pointer 15 is inserted into the fixture 7 of a putting cup 1 as described above . the vertical line 25 projected by the laser because of the cylindrical lens 21 is projected on the putting surface or floor 18 as a long straight fixed unmoving line 26 . the length of this line is dependent upon the focal length of the cylindrical lens 21 , the angle that the laser pointer 15 is tilted with respect to the floor or surface 18 , and height of the laser above the surface 18 . it has been found that with a 2 inch focal length cylindrical lens 21 , a 1 . 5 degree tilt , and the laser beam 2 . 0 inches above the surface 18 , the resulting laser line 26 will be projected for approximately 20 feet . the orientation of the cylindrical lens is positioned for refraction the beam in the vertical axis . the inherent asymmetry of laser diode output beam cross - section can be manifested in line length and width adjustment by rotating the laser pointer 15 within the tube 11 relative to the cylindrical lens 21 . other combinations of the lens focal length , laser tilt , and laser beam height can be used to obtain similar results . the length of the laser line should remain somewhat less than 20 feet to maintain brightness and therefore maximum visibility by the golfer . fig5 shows that the projected vertical laser light beam 25 propagates to a segment of a wall 20 and is observed on surfaces that reflect the laser light from the floor as a line 26 and from the wall as a vertical line 27 . fig6 shows a similar laser beam 28 from the cup 1 with its projected line 29 on the floor with a golf putter club 30 in position to practice putting . when the golfer places the putter blade 31 on top of the line 29 , the laser beam is projected in a straight line 31 on the top of the putter blade . the placement of the putter obstructs the previous beam projection on the wall and behind the putter head with the non - obstructed portion of the laser beam on the wall 32 projected as a line 33 . after the putter has been properly aligned by reference to the laser beam line 29 , a ball can be placed on the line 29 between the putter 31 and the hole 3 in a practice cup 1 . the golfer can then practice his putting stroke knowing the exact line or path to the cup / hole or target . stroking the ball along the laser beam line can be observed to monitor proper direction of the ball on its route to the hole . this exact ball position relative to the laser beam line throughout its travel to the hole provides insight into correct putting . the golfer can also monitor his putter head alignment prior to stroking . this is displayed in fig6 where the projected laser beam line on top of the putter head should be normal to the putter face . most putter heads include an alignment line 34 , as shown in fig7 which alignment line is perpendicular to the putter club face and therefore parallel to the correct alignment . proper putter club head alignment at address will show that the putter head alignment line 34 on top of the putter head is parallel to the projected laser beam 35 . to enhance the display of this projected laser beam 35 on top of the putter head 36 , fig7 shows an attachment 37 to the top of the putter club head . in this embodiment , a 1 / 2 inch thick optically clear plastic ( e . g . acrylic ) plate 37 functions as the laser beam display medium attachment . this optical plastic typically includes adequate bulk imperfections that scattered the laser beam clearly displaying the path of the laser beam as a line 38 through the clear window - like material . this clear material not only displays the correct alignment to the putting target or hole but it allows clear visibility of the top of the putter . this offers minimum disturbance to the golfer and an unobstructed view of the putter club head alignment mark 34 . the golfer can then verify alignment of his putter head to the laser illuminated target path 35 . this alignment is visible not only during address but also during the actual putting stroke . the putter alignment display device can assume several geometries . the objective is to clearly display the laser beam on top of the putter . the embodiment shown in fig7 is a clear plastic rectangle which can be attached to the top of the putter head . another embodiment , as shown in fig8 has a putter head 40 and its alignment markings 41 with the projected laser beam 42 with a folded piece of thin plastic or paper sheet 43 connected to the back side of the putter head . this clearly displays the laser beam segment 44 aligned relative to the putter head marking 41 . fig9 shows another embodiment in which a putter head 45 has a clear plastic angled attachment 46 attached to the backside of the putter . the display enhancers 37 , 43 and 46 are sufficiently light that they do not interfere with golfer &# 39 ; s putting stroke or with the feel or balance of the putters to which they are attached . fig1 shows another embodiment in which a conventional electrically operated automatic ball return putting cup 48 has been equipped with a laser beam emitter 49 and lens 50 . the emitter 49 may be an inserted laser pointer 15 , as described above , or emitter 49 may be a dedicated permanent laser diode beam emitter that operates off of the ac power supply for the ball return apparatus in cup 48 that has been adjusted by a transformer to the voltage required to produce a visible light beam 51 . the angle and location of the emitter 49 and lens 50 are oriented as described for the above embodiments with reference to the center of the hole 52 and the putting surface 53 so that a line 54 of visible laser light extends diametrically across the center of the hole along the putting surface 53 away from the center of the hole . it has thus been shown that the laser employed to practice the methods of this invention can be a visible laser diode emitter which is inexpensive and is powered by small batteries . a commonly available suitable laser product is the shirt pocket laser pointer which typically resembles a writing pen . this invention accommodates a laser pointer 15 which can be inserted into the putting cup 1 as the laser source . permanent installation on cup 48 of a dedicated laser diode that operates off of the cup power supply is another equally valid approach . projection of the laser line , such as 35 , over an alignment line on the top of the putter head provides confirmation of proper club alignment . the addition of a plastic laser line display device , such as 37 , 43 or 46 , which can be attached to the putter , enhances the alignment display but does not interfere with the putting stroke . when not being used during a practice putting session , the pointer 15 can be removed and used as a conventional laser pointer . the dual use of the laser pointer is a convenience and a practical result of the manner in which it is used to practice this invention . while the present invention has been described with reference to particular embodiments and methods , it is not intended to illustrate or describe all of the equivalent forms or ramifications thereof . also , the words used are words of description rather than limitation , and various changes may be made without departing from the spirit or scope of the invention disclosed herein . it is intended that the appended claim cover all such changes as fall within the true spirit and scope of the invention .
apparatus and methods for practicing golf involve the use of a projected laser light beam that acts as a fixed guide to the hole or target .