Abstract:
A compact disc handler includes a picker elevator containing a helically threaded lead screw journaled for rotation about a vertical axis and having a traveling nut thereon to which a disc picker arm is attached. A guideway in the tower cooperates with the picker arm to constrain the picker arm from rotating until reaching a predetermined height elevator. Using this design, a CD can be retrieved from an input hopper, placed in a label printer or other CD publishing/playing device and upon completion of same operation on the disc, it is transported by rotation to an output hopper.

Description:
BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates generally to a compact disc handler, and more particulaautomatically transferring a blank compact disc from a supply hopper into a label printer and thereafter transferring the labeled compact disc to an output hopper. 
     II. Discussion of the Prior Art 
     Compact discs are frequently used to record high quality audio and video information. Such discs are also used to record information, including computer software and data of various types. The discs are characterized by a construction which is formed of a plurality of layers, including a reflective inner layer and a protective top layer upon which characters and graphics can be printed using an appropriate printing mechanism. Such discs are commonly referred to as CD&#39;s or DVD&#39;s. 
     There currently exists a number of devices for labeling compact discs and for recording information on them. Typically, such equipment is very expensive, consumes much space and is designed for mass production of compact discs. Factories incorporating such equipment generally have separate work stations and utilize a variety of methods for loading and unloading the discs with respect to the individual work stations and for transferring the discs from work station to work station. 
     As is further pointed out in a U.S. Pat. No. 5,946,216 to Hollerich, the prior art apparatus for picking and placing compact discs have serious drawbacks. While the mechanism described in the Hollerich &#39;216 patent constitutes an improvement over the then prior art, the present invention constitutes yet a further improvement in disc handling equipment that obviates a need for translating the input hopper and output hopper relative to a path of linear vertical travel of a picker arm. This typically required separate motors for the elevator mechanism and for the input and output hopper translating mechanism. The present invention does away with the need for multiple motors and, accordingly, results in a significantly lower priced CD publishing/labeling machine. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided a compact disc handler for use in compact disc publishing systems where the handler comprises a base member that is adapted to rest on a horizontal surface. A tower is affixed to the base and projects vertically therefrom. Journaled for rotation about a vertical axis within the tower is a helically threaded lead screw having a traveling nut disposed thereon and which is adapted to move in a vertical direction determined by the direction in which the lead screw is driven. Affixed to the traveling nut and extending laterally therefrom is a compact disc picker arm, including solenoid-operated disc grasping fingers that cooperate with the central aperture in CDS and which are movable between a first gripping position and a second non-gripping position. Further in accordance with the invention, means are disposed within the tower for allowing rotation of the picker arm with the lead screw only when the traveling nut reaches a predetermined vertical elevation on the lead screw. 
     Because of the ability of the picker arm to not only move up and down vertically but also to rotate when at a certain level of elevation, the input and output hoppers can be stationary and are located beneath the path of rotation of the gripping fingers on the picker arm. 
     The lead screw is adapted to be driven by a stepper motor that is controlled by a microprocessor-based controller. As such, the position of the picker arm along the lead screw relative to a predetermined home position is known at all times. Thus, the compact disc handler of the present invention is capable of first selecting a blank CD from an input hopper, elevating it to a location above the slide drawer of a label printer, releasing the blank into the slide drawer when extended, again picking the labeled CD from the extended slide drawer upon completion of the labeling operation and transferring the labeled CD into a stationary output hopper by rotating the picker arm carrying the disc through a predetermined angle. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts. 
     FIG. 1 a perspective view of a CD label printing machine incorporating the present invention; and 
     FIG. 2 partial perspective view of the elevator mechanism employed in the machine of FIG.  1 . 
     Applicant notes that the detailed description describes FIGS. 1 and 2. As such, reference to FIGS. 3 and 4 have been removed from the description of the drawings. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the device and associated parts thereof. Such terminology is intended to include the words above specifically mentioned, derivatives thereof and words of similar import. 
     Referring first to FIG. 1, there is indicated generally by 10 a CD label printing machine constructed in accordance with the present invention. It is seen to include a base member  12  supporting a box-like stand  14  thereon and resting atop the stand  14  is a commercially available CD label printing machine  16 . Without limitation, the label printer  16  may be of the type manufactured and sold by Primera Technology Inc. It includes a slide drawer  18 , that under microprocessor control, can be made to slide open to receive a CD thereon and then close to carry the CD to the label printing station. Slide drawers of the type described are found on a variety of devices, including PC&#39;s, CD players, etc. 
     Shown resting on the upper surface  20  of the base  12  is a blank disc input hopper  22  comprising a hopper base member  24  with three spaced-apart posts  26 ,  28  and  30  projecting vertically therefrom. The spacing is such that standard sized CD&#39;s, when lowered from above, will be constrained against lateral movement. 
     Also located on the upper surface  20  of the base  12  is an output hopper which may comprise a spindle  32  that projects upwardly from a base member  34 . The positioning of the output spindle  32  relative to the input hopper  22  is such that the vertical center line of each is located on a common circular radius for reasons which will become apparent as the description of the invention continues. 
     Also mounted on the base  12  and projecting vertically from its upper surface  20  is a picker elevator assembly  36 . It comprises a generally cylindrical tower  38  having a vertical slot  40  formed therein through which a CD picker arm  42  projects. Through the slot can be seen a helically threaded lead screw  44 . The lead screw is journaled for rotation in a bearing  46  disposed in the base  12  and in a similar bearing (not shown) disposed in an end cap  48  of the elevator tower  38 . 
     Referring next to FIG. 2, details of the picker elevator  36  will next be described. Threaded onto the helical lead screw  44  is a traveling nut  50  to which the picker arm  42  is attached. The lead screw  44  is adapted to be driven by a digital stepper motor  52 , via a belt and pulley coupling arrangement  54 . The stepper motor  52  may be located within the box-like stand  14  with the belt and pulley arrangement  54  within the base  12 . The motor  52  can rotate the lead screw in either the clockwise or counter-clockwise direction under control of a microprocessor-based motor drive control circuit (not shown). 
     Contained within the cylindrical housing  38  of the picker elevator  36  are first and second closely spaced, vertically extending guide rods as at  56  and  58  that define a guideway  60  therebetween. The guide rods are of unequal length with the guide rod  56  ending at a predetermined height elevation below the upper end of guide rod  58 . Affixed to the picker arm  42  and projecting horizontally from an inner end  62  thereof is a keeper arm member  64 . So long as the keeper arm  64  is constrained in the guideway  60  between the guide rods  56  and  58 , the picker arm  42  can only be translated vertically up and down. 
     When the keeper arm  64  reaches the predetermined height elevation defined by the upper end of the shorter guide rod  56 , the keeper arm is no longer constrained and it allows the picker arm  42  to rotate in a horizontal plane about the axis of the lead screw  44  as indicated by the double-headed arrow  66  (FIG.  1 ). 
     To impart a rotational torque to the picker arm  42 , there is affixed to the top of the lead screw  44  the circular top plate  48  and disposed beneath it is a spool  70  having a flange  72  at the lower end thereof. The flange is cut or notched to define an arm segment  74  terminating in an inverted U-shaped clasp  76 . A coil spring  78  is wrapped about the spool  70  with one end of the spring being fastened to the upper circular cap  48  and the other end of the spring being fixed to the spool  70 . The clasp  76  is adapted to engage a clasp block  80  that projects upwardly from the picker arm proximate its inner end  62  when the keeper arm  64  begins to clear the upper end of the guide rod  56 . 
     Now, as the stepper motor  52  continues to rotate the lead screw  44 , the upper cap  48  rotates with it to thereby tension the spring  78  and carry the clasp  76  engaging the clasp block  80  until the picker arm  42  swings to its drop location for depositing a disc onto the output spindle  32 . Once the disc is released from the picker arm, the microprocessor reverses the direction of rotation of the lead screw causing the picker arm to again swing back until its keeper arm  64  abuts the taller of the guide rods  58  at the predetermined elevation above the top of the shorter guide rod  56 . As the lead screw keeps rotating, the picker arm begins to descend and a point is reached wherein the clasp block  80  is no longer engaged by the clasp  76 . At this point, the tension in the spring  78  rotates the clasp back to its home position. 
     The grasping fingers on the picker arm are not shown in the drawings, but they are preferably constructed and made to operate in the same fashion as the grasping fingers disclosed in the afore-referenced Hollerich &#39;216 patent, the contents of which are hereby incorporated by reference as if set forth in full herein. 
     OPERATION 
     Referring to FIG. 1, when beginning a CD labeling operation, a stack of approximately 80 discs may be loaded into the input hopper  22  and then the input hopper is positioned onto the upper surface  20  of the base  12 . Upon energization of the stepper motor  52  by the microprocessor-based motor driver, the picker arm  42  is first made to descend onto the topmost disc in the input hopper. Upon sensing the presence of a disc in the hopper, a solenoid is energized to compress the grasping fingers together so that they may enter the central aperture of the disc in the manner described in the Hollerich patent. An optical sensor controls the solenoid, causing it to be de-energized such that the grasping fingers extend to grip the edges defining the central aperture in the CD. The drive motor  52  will then reverse, causing the picker arm to be elevated to a height that is above the elevation of the slide drawer  18  of the printer module  16 . The slide drawer  18  then extends and when the grasping finger solenoid is again energized, the disc will drop into the drawer and the drawer will retract into the printer module  16  where a predetermined label is applied to the theretofore blank disc. 
     Upon completion of the printing operation, the drawer  18  will again extend and the picker arm  42  will be made to move downward until the disc is sensed at which point the gripper fingers again grasp the finished CD. Once grasped, the rotation of the lead screw is again reversed causing the picker arm to rise. When the picker arm reaches a predetermined height elevation at which the keeper arm  64  is above the top of the shorter guide rod  56 , the clasp block  80  becomes engaged in the clasp  76 . Continued rotation of the lead screw begins to tighten the spring  78  and ultimately to swing the picker arm  42  carrying the disc with it to a location where the central aperture in the disc becomes aligned with the spindle  32  of the output hopper. At this point, the picker arm solenoid is again actuated causing the grasping fingers to release the CD whereupon it falls onto the base  34  of the output hopper. 
     With the release of the finished CD onto the output spindle, the stepper motor  52  again reverses direction with the engagement of the clasp  76  with the clasp block  80  carrying the picker arm back to the point where the keeper arm  64  strikes the upper end portion of the longer guide rod  58 . This prevents further rotation of the picker arm and it begins to descend. As the keeper arm  64  enters the guide slot  60  between the parallel guide rods  56  and  58 , the clasp block  80  disengages from the clasp  76  and now the tension stored in the spring  78  returns the spool  70  so that its clasp  76  is at a home position. At this point, the picker arm  42  is again above the input hopper ready to engage the topmost disc in the hopper and repeat the foregoing cycle of operation. When a point is reached when there is no longer any blank discs in the input hopper, the optical sensor in the picker arm  42  detects that condition and operation is ceased. 
     In the afore-referenced Hollerich &#39;216 patent, the input and output hoppers had to be transported on a drawer and translated back and forth relative to a picker arm that could only be translated vertically and not rotated. The need for a hopper transporter and mechanics, along with a separate motor for driving same is obviated in the present design by providing a picker elevator that allows the picker arm to not only move up and down vertically, but also to rotate in a horizontal plane upon reaching a predetermined height elevation. This allows the disc to be positioned over a stationary output hopper. 
     This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.