Abstract: Accessories are disclosed for use with a laser tool which may or may not be self-leveling. The accessories include one or more diffraction elements, effective to receive the incoming beam and produce a plane of diverging laser beams. In preferred embodiments the diffraction elements are self-leveling. When the diverging beams are directed against a surface such as a floor, wall or ceiling, a series of discrete spots define a visible reference line useful in construction layout. The spots themselves may each locate the position of a fastener to be installed, for example, by giving the approximately correct spacing for reference of the user. The generation of discrete spots rather than a solid line, as would be generated by a cylindrical lens, better allocates laser power by providing brighter, more visible reference elements on the wall or ceiling.

Abstract: A multiple window data reading device and method for reading symbols such as bar codes through each window, data reading being focused to different focal distances in the scan volume with sensors provided to control focal distance setting from each of the windows.

Abstract: A construction laser tool which projects a plumb beam is provided with a marking template, movable and separate from the tool's housing but securable to the housing, for transferring a point on a floor to the laser beam or, in another case, for transferring the beam to locate a point on the floor. The template has a marker such as a hole to receive a pencil, and the marker is positioned under the laser tool housing, on the vertical line of the plumb beam where the floor point of interest cannot be seen, when the plumb beam is projected at a point on the ceiling. To accurately mark the floor point, the user holds the template in place on the floor and moves the laser tool away to gain access to mark the point. The reverse procedure is used to align the plumb beam over a known point on the floor. Several arrangements involving sliding templates are disclosed.

Abstract: A bar code scanning system such as for use in retail checkout having a scanner housing; a plurality of surfaces facing a scan volume from different directions; and sets of pattern mirrors positioned adjacent the respective surfaces, the housing being positioned above the scan volume and containing one or more laser beam modules and/or a scanning mechanism for producing scanning beams which are routed to the pattern mirrors and out through the respective surfaces into the scan volume.

Abstract: A system for use in construction or similar activities, for layout of points or lines using a projected laser beam includes a remotely controlled turntable unit having a rotatable turntable for receiving a portable, hand-carryable self-leveling laser projecting instrument. The portable self-leveling laser instrument preferably has a relatively wide self-leveling range, such as up to about 4.degree. in two axes, and is useful in layout operations separate from the remote turntable. When placed on the remote turntable unit, the direction of pointing of the laser or lasers from the instrument can be controlled by the operator from a distance, through operation of a hand-held remote unit having directional buttons which control a motor of the turntable unit. Provision can be included for measuring angles on the turntable unit, for varying the speed of rotation of the turntable, as by holding down one of the buttons, and for generating a preselected angle (such as 90.degree.) from a remote position.

Abstract: An automatic plumb, level and pointing tool uses a visible laser diode to project light beams in two modes through two windows. In the first mode of operation, the unit is able to project a plumb-up beam and a level beam of light while resting on a surface which is as much as 5.degree. out of level. In the second mode of operation the unit is able to project two orthogonal beams or light both approximately in the horizontal plane for aligning one or more reference lines. Accurate, low cost methods of generating level and plumb beams and planes of light are disclosed. One method uses an approximately or partially leveled platform combined with a refractive correction as a second stage.

Abstract: Efficient and cost-effective generation of two co-linear laser beams or two or more intersecting beams, for the purpose of alignment as in the construction industry, takes advantage of the unequal divergence of light from a typical laser diode that produces a beam of elliptical cross section. Two roughly equal co-linear beams of light, or two or more intersecting beams, can be generated by reflecting the collimated elliptical beam from preferably two mirror surfaces oriented obliquely to the beam and so as to divide the elliptical beam in two. If one of the reflective surfaces is a beam splitter, three essentially intersecting beams can be generated. In preferred embodiments these three beams are at right angles to each other, particularly for use in construction layout.

Abstract: An apparatus for use with a compact self-leveling construction laser for the purpose of allowing the user to remotely call or page the measurement beam to his location using a retroreflector. The apparatus uses an auxiliary plumb beam provided by the construction laser for scanning the job site in search of the cooperative reflector. The invention consists of a construction laser, motor driven turntable assembly to which the construction laser is attached and a cooperative reflector carried by the operator.

Abstract: A quick action bar clamp has provision for mounting an alignment laser instrument on one jaw of the clamp. The mounting provision allows manual pointing of the laser to facilitate projecting a level line or plane of light with a self-leveling laser instrument. By engagement of the clamp on a fixed structure such as a column, wall stud or door frame, the operator can quickly bring the laser instrument into its self-leveling range and easily adjust the beam height. The attachment of the laser instrument to the clamp is via a threaded rod or a magnetic attachment retention. An L-shaped magnetic attachment can be used in another procedure, to connect the laser to the steel slide bar of the clamp.

Abstract: A self-leveling plumb, level and pointing tool uses a visible laser diode to project light beams in two modes through two windows. Accurate, low cost structures for generating level and plumb beams and planes of light are disclosed. In principal embodiments, all leveling is accomplished using a very flexible coil spring as a pendulum element, a chain link connection in combination with such a spring, or a point contact suspension. Several accessories are disclosed for use with the laser tool. One accessory is a beam deviation accessory which can be used with the self-leveling laser tool to project a beam of known inclination. The accessory uses a pair of lenses whose relative positions are shifted to generate the desired angle.

Abstract: A self-leveling plumb, level and pointing tool uses a visible laser diode to project light beams in two modes through two windows. Accurate, low cost structures for generating level and plumb beams and planes of light are disclosed. In principal embodiments, all leveling is accomplished using a very flexible coil spring as a pendulum element, a chain link connection in combination with such a spring, or a point contact suspension. Several accessories are disclosed for use with the laser tool, as well as other embodiments.

Abstract: The present invention relates to the efficient and cost-effective generation of two co-linear laser beams for the purpose of alignment, particularly in the construction industry. The unequal divergence of the light from a typical laser diode produces a beam of elliptical cross section. Two roughly equal co-linear beams of light can be generated by reflecting the collimated elliptical beam from two mirror surfaces at 90.degree. to each other or a single element dividing the elliptical beam in two. Techniques are described for generating offset parallel beams, and for correcting for inherent knife-edge diffraction effects due to division of the beam.

Abstract: A bar code scanning system such as for use in retail checkout in which the scanning system has a conveyor defining a first surface and a second surface disposed adjacent the first surface and arranged generally orthogonally thereto forming a scan volume therebetween; sets of pattern mirrors positioned adjacent the respective surfaces; and one or more laser beam sources associated with a rotating mirror polygon for producing scan patterns which are routed to the pattern mirrors and out through the respective surfaces into the scan volume.

Abstract: An automatic plumb, level and pointing tool uses a visible laser diode to project light beams in two modes through two windows. In the first mode of operation, the unit is able to project a plumb-up beam and a level beam of light while resting on a surface which is as much as five degrees out of level. In the second mode of operation the unit is able to project two orthogonal beams of light both approximately in the horizontal plane for aligning one or more reference lines. An accurate, low cost method of generating level and plumb beams and planes of light is disclosed. One method uses an approximately leveled platform combined with a weak optical correction. The approximate leveling is done using a single wire or coil spring pendulum element which allows the platform to level itself to within a small fraction of true level, and remaining correction is provided by a weak negative lens or a weak reverse telescope.

Abstract: A pipe alignment device and method is provided for efficiently generating an air flow in sections of pipe such that the sections of pipe may be aligned along a prepositioned reference laser beam without refraction errors. A fan blade assembly is supported in one end of the pipe section by a support frame. A motor, mounted on the frame, rotates the fan blade assembly through a plurality of intermeshed gears to generate a air flow in the pipe. The fan blade assembly defines a light transparent aperture which permits the reference laser beam to enter the pipe sections concomitantly with the generated air flow. The light transparent aperture may include a window disposed therein.

Abstract: Two resonant cantilever beams oscillate in a sinusoidal pattern. Mirrors disposed on the oscillating ends of the cantilever beams are used to multiplex two scanning and collecting light beams. The cantilever beam parameters and mirror configuration are selected so that the scanning light beam is on the first mirror during the linear portion of its scan. As the first cantilever beam oscillates out of the linear portion of the sine wave, the deflection of the first mirror is just great enough to allow the scanning beam to strike the second mirror during the linear portion of the second mirror's scan. The process is repeated twice each cycle. The collection lens is large enough to receive the full aperture of both mirrors at all times. Multiplexing of scanning diodes is also accomplished by a controller circuit which alternately enables diodes disposed on the ends of respective first and second cantilever beams during the linear portion of each sine wave oscillation.

Abstract: An automatic plumb, level, pointing and distance measuring tool uses a visible laser diode to project a beam in any of several different modes through a beam exit window. The tool, approximately the size and shape of a tape measure, can be placed on one edge to project a tilt-compensated vertical beam. Placed on another edge 90.degree.-rotated, the tool projects through the same exit window a tilt-compensated horizontal beam. When laid on either of its larger flat sides, the tilt compensation becomes inoperative and the tool projects a beam which is fixed relative to the housing. Acoustic distance measurement is facilitated using a second component or target side device which receives both a light beam an acoustic signal simultaneously projected from the laser tool across a space to be measured. A receiver in the target side device first detects arrival of a characteristically modulated or pulsed light beam, received at a photodetector on the target side device, and then receives the acoustic signal.

Abstract: An automated retail point of sale scanning system includes a means for preferentially aligning an item traveling on an item path and through a scanning region such that two or more surfaces to be scanned are stably maintained in a substantially coplanar alignment with a corresponding focal plane of a bar code scanner. Two orthogonally disposed belts define an item path. The belts are tilted at an angle from the horizontal so that an item placed on either belt will have at least two surfaces stably registered by gravity, one surface to each adjacent belt. Alternatively, a stationary platen is disposed orthogonally to a transport belt such that at least two surfaces of the item being scanned are stabilized in a focal plane coplanar with a bar code scanner, one surface of the item being stabilized against the platen and another surface being stabilized against the adjacent transport belt.

Abstract: A bar code scanning system which can be operated in two scanning categories: hendheld and fixed. The system incorporates a second scanning element having a fixedly mounted mirror and a dithering mirror disposed in relation to a hand-held scanner which is removably positioned in a holder means.

Abstract: A point of sale (POS) bar code scanner such as in common use in retail stores includes provision for reading bar coded redemption coupons (or other bar coded documents redeemable for value) in a manner secure from a human operator. Integration of functions between the POS scanner and the coupon reader varies with different embodiments described. Through software associated with bar code decoding logic, a comparison is made between information on a validation coupon and information on items presented for purchase, and a decision is made as to whether the redemption coupon is valid and redeemable in this transaction. In one embodiment, the bar code scanner simply receives the redemption coupon face down on the product scanner window, and integrated decode logic of the scanner identifies the bar code as belonging to a redemption coupon, then makes the comparison and validation of the coupon for the particular transaction.