Abstract:
A method and apparatus for printing large format lenticular images on a lenticular sheet ( 902 ) having a plurality of generally parallel lenticules ( 903 ) on a front side of the lenticular sheet ( 902 ). A sensor ( 209 ) senses a beginning of each lenticule ( 903 ). A printhead ( 102 ) prints interleaved image information on the lenticular sheet ( 902 ) in a series of swaths ( 220 ). A width of each of the swaths ( 220 ) is less than a width of the lenticular sheet ( 902 ). Each of the swaths ( 220 ) is printed in a direction parallel to the lenticules ( 903 ) and each of the swaths ( 220 ) is printed in a direction perpendicular to the lenticules ( 903 ).

Description:
FIELD OF THE INVENTION 
     The present invention relates in general to printing stereoscopic images, multiple images, or motion images; and in particular to a method for printing interdigitated images or a lenticular medium. 
     BACKGROUND OF THE INVENTION 
     Lenticular overlays are a means of giving images the appearance of depth. A lenticular image is created using a transparent upper layer having narrow, parallel lenticules (semi-cylindrical lenses) on an outer surface, and an image-containing media. The two layers form a lenticular system wherein different portions of an image are selectively visible as a function of the angle from which the system is viewed. 
     If the image is a composite picture made by bringing together into a single composition a number of different parts of a scene photographed from different angles and the lenticules are oriented vertically, each eye of a viewer will see different elements and the viewer will interpret the net result as depth of field. The viewer may also move his head with respect to the image thereby observing other views with each eye and enhancing the sense of depth. When the lenticules are oriented horizontally, each eye receives the same image. In this case, the multiple images give illusion of motion when the composite image is rotated about a line parallel to a line formed by the viewers eyes. 
     Whether the lenticules are oriented vertically or parallel, each of the viewed images are generated by lines of images which have been interlaced at the frequency of the lenticular screen. Interlacing lines of each image is referred to as interdigitation. Interdigitation can be better understood by using as an example four images used to form a composite with a material having three lenticules. In this example, line  1  from each of the four images is in registration with the first lenticule; line  2  from each of the four images is in registration with the second lenticule; etc. Each lenticule is associated with a plurality of image lines or an image line set, and the viewer sees only one image line of each set with each eye for each lenticule. It is imperative that the image line sets be registered accurately with respect to the lenticules, so that the proper picture is formed when the assembly is viewed. 
     Conventional recording of linear images on a lenticular recording material has been accomplished with a stereoscopic image recording apparatus that uses optical exposure. A light source, such as a halogen lamp, is projected through an original image, through a projection lens, and focused on lenticular material. The images are exposed on a receiver attached to the lenticular material as linear images. Japanese (Kokoku) Patent Application Nos. 5473/1967, 6488/1973, 607/1974, and 33847/1978 disclose recording apparatus in which two original images are projected for printing on a lenticular recording material. Recording composite images in this fashion requires complex lens structures, which are expensive. 
     In contrast, image recording by scanning exposure requires comparatively simple optics, has great flexibility in adapting to various image processing operations, and to alterations in the dimension of the lenticules. To take advantage of these features, various apparatus and methods have been proposed for recording image by scanning exposure. For example, Japanese (Kokoku) Patent Application No. 3781/1984 teaches a stereoscopic image recording system in which a plurality of original images is taken with a TV camera, processed and stored in frame memories from which the stored image signals are retrieved sequentially as linear images in accordance with the pitch of lenticular lenses used. After the linear images are recorded on a recording material by scanning exposure, the lenticular sheet is bonded to the recording material. Another scanning method uses polygon scanners, described in U.S. Pat. No. 5,349,419, for exposure of photosensitive stereoscopic images directly on lenticular materials. 
     In order to manufacture lenticular images, a small spot size and long straight uniform scan lines are needed. U.S. Pat. No. 3,485,945 describes a system for producing high quality lenticular images writing images directly onto the back of lenticular material. 
     One inherent limitation of direct writing techniques is that in order to achieve large high resolution images the scan lines must be written with a small spot size and must be written as long straight lines. This results in a scan line length to spot size ration, which is so large as to be impractical. As a result, the optical design of the device for scanning the lines which form the image, and which must provide a uniform scan which maintains linearity alignment and spot size specifications throughout its scan length, becomes impractical. Whether the scanning device is a cathode ray tube, a scanned light beam, a scanned beam of electrons, a thermal resistive head, or other image-scanning device, the requirement of small spot size and long, straight, uniform scan lines may not be achievable at a reasonable cost. This problem is aggravated because the scan lines must be parallel to the lenticules or across the lenticules, throughout the entire length of the scan. 
     To make large, high quality lenticular images requires writing scan lines which are accurately aligned to the lenticular material over the entire of the image. Because the precision required is proportional to the number of views and the size of the lenticules, increasing the size of the lenticules and reducing the number of views has solved the problem in the past. The disadvantage of decreasing the number of lenticules is that the image has lower apparent resolution and the lenticular material must be thicker making the image heavier and more expensive because of the additional material required. Another disadvantage of decreasing the number of views is that all the overall image quality is reduced. 
     In prior art applications, lenticular views have been digitally written in a single scan thereby limiting the dimensions of the image produced to the size of the printer scan, or necessitating the use of an enlarger which decreases image quality and increases the cost of manufacturing. See Method for Enlarging Images for Lenticular Prints by R. R. A. Morton, U.S. Pat. No. 5,673,100. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method and apparatus for printing large format lenticular images. 
     According to one aspect of the present invention, an apparatus for printing large format lenticular images on a lenticular sheet having a plurality a generally parallel lenticules on a front side of the lenticular sheet, comprises a sensor which senses a beginning of each lenticule. A printhead prints interleaved image information on the lenticular sheet in a series of swaths wherein a width of each of the swaths is less than a width of the lenticular sheet. In one embodiment, each of the swaths is printed in a direction parallel to said lenticules. In another embodiment, each of the swaths is printed in a direction perpendicular to said lenticules. 
     In the preferred embodiment, a narrow scanning spot prints on a silver halide emulsion on a backside of the lenticular sheet. According to another aspect of the invention, the spot is elongated. 
     An advantage of the present invention is that when printing in swaths perpendicular to the direction of the lenticules, lenticular rows, which are not straight, do not degradate the quality of the image. 
     The invention and its objects and advantages will become more apparent in the detailed description of the preferred embodiment presented below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a perspective view of a printhead, printing swaths on a media according to the present invention. 
     FIG. 2 shows a schematic view of a controller for a printhead according to the present invention. 
     FIG. 3 shows a plan view of scan lines for adjacent swaths. 
     FIG. 4 shown a plan view of scan lines in adjacent swaths for an alternate embodiment of the present invention. 
     FIG. 5 is a graph showing blending of data from the embodiment shown in FIG.  4 . 
     FIG. 6 is a schematic view of blending video amplitude data. 
     FIG. 7 shows misalignment of reference marks in the media. 
     FIG. 8 is a schematic view of a servo system for correction of angular position. 
     FIG. 9 shows a perspective view of the media and media. 
     FIG. 10 is a perspective view of the media and media. 
     FIG. 11 is a schematic view showing writing of data to the media through the media. 
     FIG. 12 is a schematic view with the scan line direction perpendicular to the lenticular direction. 
     FIG. 13 is a schematic view showing printing through the lenticules. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows an media  101  on which is to be placed an image. The media  101  used for printing lenticular images is typically comprised of parallel rows of lenticules on a first side of the media  101  and a receiver on another side of the media. A printhead  102  traverses the media in direction  103  to sweep out swaths  110 ,  111 ,  112  and  113  across the media. The direction of the printhead swath  112  may be in direction  104  or in direction  105 . Thus, printhead  102  after printing swath  111  in direction  103  may return to the beginning of swath  112  and print in a direction  105 , or after completion of swath  111  the printhead may be moved laterally and print swath  112 , moving in a direction  104 . 
     The printhead  102  may be a laser scanner, cathode ray tube, thermal resistive head, an ink jet head, or other device for directing energy or dye to the media  101 . In the case of directing energy on the media, the printing process may be comprised of silver halide, dye sublimation thermal, dye diffusion thermal, wax transfer thermal, electrographic, ektaflex or other image forming means. 
     The control of the printhead  102  is a system which senses preexisting positional data which has been incorporated into the media  101 . The signals from this preexisting positional data are used to control the position of the printhead  102  and the flow of image information from the printhead  102  onto the media  101 . 
     FIG. 2 shows a controller  119  for controlling the position of the printhead  102 . Table  201  supports media  101  and is moved in directions  202  and  203  by control motors  205  and  204 . These motors are connected to lead screws  206  and  207 , and are driven by servo system  208 , which receives control signals from magnetic sensors  209  and  210 . Printhead  102  traverses the media  101  as motor  205  turns leadscrew  207  to drive an engaging nut (not shown) and table  201 , which supports media  101 . Image information passes from image rendering device  211  to printhead  102  along connection  212 . Rendering device  211  produces desired X and Y positional data along line  214  to servo system  208 . Direction X corresponds to direction  203 , and Y corresponds to direction  202 . 
     Data from sensors  209  and  210 , corresponding to X, Y coordinates, is compared in servo system  208  with the desired XY location generated on line  213  by renderer  211 , and servo system  208  generates control signals to motor  205  and motor  204  along line  214  so that the position of table  201  corresponds to the desired position specified by renderer  211  on line  213 . Thus, along the central swath  221  of the three swaths,  220 ,  221  and  222 , an image is written at points predetermined by sensors  209  and  210 , sensing reference marks, or preexisting positional data, which is written in magnetic form on the underside of media  101 . It will, however, be appreciated that other marks such as infrared, fluorescent inks, embossing marks, electrostatic signals, x-ray detectable signals, changes in resistively, elevation, or other locating marks could be used. 
     In order to write swath  220 , table  201  is moved by servo motors  204  and  205  to the position shown in FIG.  2 . That the table may move in direction  202  while keeping the sensors clear of the ends of the supports of the table  201  so that the sensors may traverse underneath the media  101  along either side of swath  220 . To achieve this, the media  101  overhangs the table  201 . It is now possible to traverse the image printhead  102  along swath  220 . The renderer  211  generates image signals along connection  212  to print swath  220  which abuts the image data along swath  221 . Renderer  211  also generates X and Y control signals to servo  208  such that the passage of image printhead  102  along swath  220  causes image data to precisely be aligned with the image data on swath  221 , as shown in FIG.  3 . 
     It will be appreciated that the arrowheads on interconnecting lines, for example  212 ,  213  and  214 , which indicate the primary but not the exclusive flow of information along these interconnecting lines. Image information, for example acknowledgement signals, device status, information associated with servo loops inside the main servo loop, homing signals, synchronizing signals, clock signals, and similar information, may pass in the direction which is opposite or the same as the arrow shown. Thus, it will be appreciated that these arrowheads are included for the clarification and understanding in the mind of the reader so as to communicate the upper level system performance of the equipment rather than the detailed performance. 
     FIG. 3 shows in magnified form the way in which scan lines traversing across swath  221  abut the scan lines associated with swath  220 . The scan lines, which comprise the swath lines, are comprised of individual pixels. For example,  301 ,  302  and  303  on scan line  310  on swath  221 ; and  304 ,  305  and  306  on scan line  311  on swath  220 . Similar arrangements also occur on scan lines  312 ,  313  as well as subsequent and precedent scan lines. 
     The scan lines need not contain exclusive abutting pixels such as pixel  303  associated with scan line  310 , and pixel  304  associated with scan line  311 . While this approach is feasible it does depend on the servo system head assembly and table shown in FIG. 2 working in cooperation to achieve positional accuracy whose magnitude is a small fraction, in the range of 0.01 to 0.50 of a pixel spacing and a scan line spacing. This range depends on the viewing conditions of the final image, the overall effective spot size of the system including the size of the spot used to write the pixels, the interactions between the dye or the colorant and the media which receives the dye or colorant. It also depends on a number of other imaging system factors including the viewing distance and visual acuity of the observer. 
     An alternate way to insure that the swaths  220  and  221  have visually imperceptible seams between them is to blend the pixels at the boundaries where the seams occur. This is shown in FIG. 4 where scan line  410  extends across the boundary  423  between swath  221  and  220  to point  420 , and scan line  411  extends across boundary  423  to point  421 , such that pixels  402 ,  403 ,  404 ,  405 ,  406  and  407  are written by both scan lines  410  and  411 . In addition, pixel  401  and adjoining pixels along scan line  410  in the direction away from pixel  402 , are only written by scan line  410 . A similar condition applies for pixel  408 ,  409  and so on with respect to scan line  411 . In this alternative implementation servo system  208  blends the pixel data as shown in FIG. 5. A profiling technique is used, which can be shown by considering positions along line  501  to correspond to the positions in the Y direction along scan lines  410  and  411 . The desired image data for pixels along scan line  410  is multiplied by a profile shown as  502  which at position corresponding to pixel  402  in the Y direction has an amplitude of unity and declines to a value of zero for pixel  408 . 
     FIG. 6 shows the way in which video amplitude data on line  601  is processed to achieve the desired blending effect. The data on  601  enters function  602  which also receives the amplitude data as a function of Y corresponding to the amplitude shown in FIG. 5 as profile  502 . This data is entered on line  603 . Function  602  may be a multiplier or a two dimensional look up function, which produces an amplitude on line  604 , which is the product of  601  and  603  or some other monotonically related function selected or experimentally determined to ensure that the blending technique produces a visually imperceptible result in the final image. For example, while the amplitude on data line  601  may correspond to the amplitude of the energy written by printhead  102  the final desired blending effect may be based on density blending rather than intensity blending and to achieve this it may be necessary that the profile along  502  as well as the relational function between the amplitude on line  603  and the amplitude on line  604  be nonlinear. Furthermore this function may vary as a function of the different color channels which are controlled through the data on  601 . Similarly, profile  503  controls the amplitude along scan line  411  so that the data corresponding to pixels  402  to  410  and subsequent pixels is modified in a manner similar to the pixels along scan line  410 . 
     It will be appreciated that generally, whether printing scan line  410  or  411 , the data on line  601  at, for example pixel  403 , will be the same however, the data on line  603  will correspond to profile  502  for scan line  410  and  503  for scan line  411 . Thus, pixels  402  to  407  are written twice, once on scan line  410  and once on scan line  411 , and the resultant visually perceived pixel is therefore less sensitive to the alignment between scan line  410  and  411  and to the alignment between adjoining pixels. 
     One other cause of misalignment is that the reference marks or preexisting positional data used to locate XY coordinates on the media  101  may not fall on a regular grid pattern. This may occur due to errors in the mechanism that positions these marks on the media or due to distortion of the media subsequently to the writing of the media. This is shown diagrammatically in an exaggerated sense in FIG. 7, wherein the preexisting positional marks for scan line  120 , which goes from one edge  130  to the other edge  131  of the media, are not perfectly aligned. Thus, instead of being as shown by the solid line, the preexisting positional marks, which are shown as  141 ,  142 ,  143  and  144 , will require that for adequate alignment scan lines be written along dashed lines  150 ,  151  and  152 . Provided these lines are straight an angular displacement of printhead  102  as it traverses swath  220 ,  221  and  222  is able to compensate for this distortion and still achieve accurate alignment of the image between the swaths. While the preexisting positional marks  141 ,  142 ,  143  and  144  may be in a straight line, the writing printhead  102  is not accurately aligned from am angular point of view to the preexisting positional marks. 
     To overcome both the problem of the preexisting positional marks not being correctly aligned, the head not being accurately aligned from an angular point of view and similar effects, it is possible, while writing the image, to make small changes to the angle of the head with respect to the direction of the motion. 
     The servo system  208  is shown in FIG. 2 has the added capability of sensing the phase difference between position sensor  209  and position sensor  210  as well as the average position. This can be used for angular correction. This is shown in FIG. 8, wherein the connecting line  231  from position sensor  210  and the connecting line  232  from position sensor  209  contain the instantaneous X, and possibly Y, coordinates of the current position of the media  101 . The X coordinates are fed to a summing function  801 . The sum of two X coordinates is divided by 2 and may be temporarily averaged to remove small amounts noise corresponding to residual noise in the current X coordinate values of the media. The same signals corresponding to the instantaneous X coordinate of the base on lines  231  and  231  from sensors  210  and  209  are sent to the subtract function  802  whose output on line  804  corresponds to the angular difference between the preexisting positional marks on the media. Again, temporal averaging may be used. The signal on line  803  corresponding to the current position is sent to the servo subsystem  805  which controls motor  205  on line  233  to control the velocity and position of the media  101 . While the subtract signal corresponding to the angular difference on line  804  goes to angular servo system  806  which through line  230  connects to motor  234 . This motor controls the angle of printhead  102  which is mechanically pivoted about axis  235  which axis is placed at the center axis of the scanning head such that angular changes do not change its average position in the X direction. Consequently, small angular changes in the position of the scan line traversing swath  221  may be made. Thus, FIG. 8 shows in more detail a portion of the operation of servo system  208 . Other components of servo system  208  for example, will include power supply, synchronizing functions etc. 
     Other methods for achieving angular alignment including rotating the media and maintaining the head stationary or rotating an element within the head so that the scanning direction is able to be angularly adjusted. Additional methods are shown in U.S. Pat. No. 5,830,194. 
     As already discussed above, there are a variety of techniques for establishing the preexisting positional marks. These include writing magnetic data on a magnetic layer which may be either on the receiver side or the lenticular of the media. Some constructions may involve the use of additional layers to embed the image-forming layer within the media. However, at the time the image is written the receiver, or image-forming layer, is generally exposed with respect to the supporting media. In addition, preexisting positional data or marks may be placed at some layer that is internal to the media at the time the image is written. 
     Other methods for forming the preexisting positional marks for referencing the image position along swaths include fluorescent dyes that may be caused to fluoresce in invisible or non-visible spectral frequencies using radiation which may also be visible or non-visible. A further method is to embed voids that may be detected ultrasonically, by optical means, or by other means. Another method is to use embedded or surface charge that may be detected to provide positional information. In addition, the resistively either surface or bulk may be modified to establish reference marks. A further method of producing is polarizing the surface of the media to provide detectable marks or to change the reflectivity or texture of the surface. 
     Another method of producing reference marks is to place yellow reference marks, which might by microscopic and therefore will not disturb the appearance of the image. Yet another embodiment uses marks which are visible only to light which is outside of the sensitive spectrum of the media such as IR marks or UV marks spectrum. Reference marks may be removed during subsequent processing of the imaging media. 
     A further method of producing reference marks is to burn pits into the surface which pits may be optically detected but may not be optically visible to the viewer. 
     A further method of producing reference marks is to use a holographic optical layer within or on the surface of the image media or image receiver layer. 
     It is also possible to collectively apply layers using photography and other methods which may be detected by sensors. These methods include thin metalization layers, oxide layers on a metalized media, oxide layers on material media and layers which exhibit other physical or chemical properties whose presence may be detected so as to determine the specific location and therefore constitute preexisting positional data or a preexisting positional mark. 
     A further method of achieving alignment between consecutive swaths is to encode within a previous swath, codes which may be detected on a subsequent swath. These codes may be written, at the same time as the image content is being written such as by encoding magnetic data into the image concurrent with writing the image. 
     Image data may also be used to generate a reference code either by writing an IR layer or by using microstructure within the visible image that does not degrade the image when viewed by the observer. 
     It is also appreciated that any of the methods described herein as well as other methods could be placed in the image media, image receiver layer or at any other position within the material which is being written upon. 
     A preferred embodiment is to use this invention to write lenticular images which are larger than a single scan width. In this case the lenticules which are preformed into the media are used as the preexisting positional data or reference marks to define the position of where scan lines are to be written. See U.S. Pat. No. 5,835,194. See also 09/033,212 “Detection of Pitch Variations in Lenticular Material”; 09/342,391 “Detection and Correction of Skew Between a Writing Laser Beam and Lenticules in Lenticular Material). 
     In the preferred embodiment an IR beam is used to sense the position of the lenticules. As shown in FIG. 9 a receiver  901  is bonded on a back surface of media  101 . A lenticular sheet  902  comprised of lenticules  903 ,  904 ,  905  and  906  is on a front surface of media  101 . An IR beam  910  illuminates the lenticular material at points corresponding to the edges of the swaths or alternatively across the full width of a swath being scanned by successive scan lines, for example scan line  911  across swath  220 . The beam is deflected at an angle  912  depending on its position with respect to the centerline of the lenticule. A linear array sensor  913  detects the reflected beam, and a signal from the sensor  913  indicates the position of the beam with respect to the lenticule on line  914 . A similar sensor, not shown, may be placed on the other side of the swath beneath the position  915 . The line  914  and the signal from a sensor positioned below  915  at the other side of the swath which signal emerges on line  916  passes to a module which processes the signal to determine the X coordinates of the media  101 , which are then sent to servo system  208  to connect at the points defined by lines  231  and  232 . 
     Alternatively, rather than have array sensors  913 , single position sensors may be used to generate a pulse whenever the beam sweeps across them. Referring to FIG. 10, an example of a single position sensor is  1001  which senses beam  910  that in this case is deflected by its relative position to the lenticule at a different angle  1002  by way of example. 
     An alternative embodiment, shown in FIG. 11, avoids the need for access to the lower side of the lenticular material and therefore simplifies the design of the stage that supports the lenticular material The lenticular material is placed on a stage  1101 , which contains on its upper surface an IR absorbing printhead  102  and the illuminating IR beam comprising collimated bundle  1104  is deflected by lens  1106  in such a way that the beam hits the media air boundary surface defined by the lenticules at right angles and light reflects back along the same path to semi-silvered mirror  1108  to produce a return beam  1110 , which is collimated to a sensor and sensed to generate a pulse signal in detector  1112  along line  1114  whenever the beam is directly above the lenticule. The resulting signal is used in element  1116  to generate an X coordinate on line  1118 . This line may then be connected to servo system  208  at the points defined by the connection of line  231  and for a similar assembly for example  211  on the other side of the swath. The output of this assembly would then be connected to the point on servo system  208  corresponding to the point where line  232  connects. To maximize the signal to noise of the responding signal it is desirable to ensure that the surface of stage  1101  is highly IR absorbent thereby minimizing spurious reflections. 
     Throughout this disclosure it will be appreciated that the principles described can be applied to other configurations for writing on imaging medias. These include a capstan drive for the media such as found in printing presses and some electrophotographic copiers. Moving the scanning head across the media while keeping the media stationary as well as other configurations. An alternative configuration is to control the synchronization of the writing image data with position of the media rather than that of the media with image data. 
     An alternative configuration is to write the scan lines across or perpendicular to the lenticules rather than parallel to the lenticules, and sense the position of the scan in relation to the preexisting positional data on the image media. The fast scan is then to controlled rather than the slow scan either by controlling its position based on the image data and the sensed position of preexisting positional data on the image media. Alternatively the scanning across the lenticules can be controlled by synchronizing the writing image data with the position of the media rather than that of the media with image data. 
     Another embodiment of the present invention is shown on FIG.  12 . In this embodiment printhead  102  prints a swath at a time with the scan line direction X being perpendicular to the lenticule direction Y. First, swath  110  is printed and then swath  111  and so on till the whole of print  101  is completed. The scan line produced by printhead  102  extends over an integer number of lenticules. The lenticules on FIG. 12 are shown as not being straight. This can be a result of manufacturing limitations of the lenticules. It is an important aspect of this embodiment that the printing is triggered by a signal derived every time the beam crosses into a new lenticule so as to correct for this deviations from straightness of the lenticules. 
     This process is explained in more detail by referring to FIG.  13 . Beam  2004  is shown as it crosses into lenticule  2003   a.  At that position, some of the beam power, goes through the lenticule and focusing lens  2010  and impinges on position detector  2007 , which is placed at the back focal plane of lens  2010 . Detector  2007  derives a signal, which is used to trigger the printing over lenticule  2003   a.  It is obvious that a separate beam can be used for the generation of the “lenticule start signal” other than the writing beam itself. The other beam can be of a different wavelength but it has to be deflected by the same deflector, which deflects the writing beam. 
     By using the “lenticule start” signal from detector  2007 , the deviations from straightness of the lenticules will not effect the quality of the print since the image position is kept in registration with the lenticules. The idea of scanning the beam across the lenticules has been disclosed by Telfer in U.S. Pat. No. 5,681,676. However, in swaths as per the present invention is not found in the prior art. 
     Scanning of a shorter swaths  2000 ,  2000   a,  rather than the entire width of the media, allows printing of very large prints, which would be impossible with a system using a long scan line. As an example consider the printing of a 40 inch by 30 inch print with the lenticules extending along the short dimension. The print time is specified as 5 minutes. Assuming 50 lenticules/inch, the total number of lenticules is 2000. The flying spot polygon based printer covers 80 lenticules. Thus, the number of swaths to cover the whole print is 2000/80=25 swaths. Assuming we have 30 multiplexed images. Therefore, the total number of pixels along the scan line is 80×30=2400. This total number of resolvable spots is very easily achievable with flying spot laser prints. Assuming that the required resolution in the y direction is 100 dots/inch. This means that the pitch between the scan lines is 25.4 microns, or 0.001 inch. From this we can calculate that we have 3000 lines in a swath. With a 10-facet polygon, the polygon will rotate at 1667 RPM. These printer specifications are easily achievable. Since the image information is already segmented by the lenticules, this particular mode of scanning across the lenticules, does not necessitate further segmentation of the image since an integer number of lenticules is covered by the scan line. 
     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention. For example, the media may be supported on the interior or exterior of a drum for printing. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 PARTS LIST 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 101. 
                 Media 
               
               
                   
                 102. 
                 Printhead 
               
               
                   
                 103. 
                 Direction 
               
               
                   
                 104. 
                 Direction 
               
               
                   
                 105. 
                 Direction 
               
               
                   
                 110. 
                 Swath 
               
               
                   
                 111. 
                 Swath 
               
               
                   
                 112. 
                 Swath 
               
               
                   
                 113. 
                 Swath 
               
               
                   
                 119. 
                 Controller 
               
               
                   
                 120. 
                 Scan line 
               
               
                   
                 130. 
                 Edge 
               
               
                   
                 131. 
                 Edge 
               
               
                   
                 141. 
                 Preexisting positional mark 
               
               
                   
                 142. 
                 Preexisting positional mark 
               
               
                   
                 143. 
                 Preexisting positional mark 
               
               
                   
                 144. 
                 Preexisting positional mark 
               
               
                   
                 150. 
                 Dashed line 
               
               
                   
                 151. 
                 Dashed line 
               
               
                   
                 152. 
                 Dashed line 
               
               
                   
                 201. 
                 Table 
               
               
                   
                 202. 
                 Direction 
               
               
                   
                 203. 
                 Direction 
               
               
                   
                 204. 
                 Motor 
               
               
                   
                 205. 
                 Motor 
               
               
                   
                 206. 
                 Lead screw 
               
               
                   
                 207. 
                 Lead screw 
               
               
                   
                 208. 
                 Servo system 
               
               
                   
                 209. 
                 Sensor 
               
               
                   
                 210. 
                 Sensor 
               
               
                   
                 211. 
                 Rendering device 
               
               
                   
                 212. 
                 Connection 
               
               
                   
                 213. 
                 Line 
               
               
                   
                 214. 
                 Line 
               
               
                   
                 220. 
                 Swath 
               
               
                   
                 221. 
                 Swath 
               
               
                   
                 222. 
                 Swath 
               
               
                   
                 230. 
                 Line 
               
               
                   
                 231. 
                 Connecting line 
               
               
                   
                 232. 
                 Connecting line 
               
               
                   
                 233. 
                 Line 
               
               
                   
                 234. 
                 Motor 
               
               
                   
                 235. 
                 Axis 
               
               
                   
                 301. 
                 Pixel 
               
               
                   
                 302. 
                 Pixel 
               
               
                   
                 303. 
                 Pixel 
               
               
                   
                 304. 
                 Pixel 
               
               
                   
                 305. 
                 Pixel 
               
               
                   
                 306. 
                 Pixel 
               
               
                   
                 310. 
                 Scan line 
               
               
                   
                 311. 
                 Scan line 
               
               
                   
                 312. 
                 Scan line 
               
               
                   
                 313. 
                 Scan line 
               
               
                   
                 401. 
                 Pixel 
               
               
                   
                 402. 
                 Pixel 
               
               
                   
                 403. 
                 Pixel 
               
               
                   
                 404. 
                 Pixel 
               
               
                   
                 405. 
                 Pixel 
               
               
                   
                 406. 
                 Pixel 
               
               
                   
                 407. 
                 Pixel 
               
               
                   
                 408. 
                 Pixel 
               
               
                   
                 409. 
                 Pixel 
               
               
                   
                 410. 
                 Scan line 
               
               
                   
                 411. 
                 Scan line 
               
               
                   
                 420. 
                 Point 
               
               
                   
                 421. 
                 Point 
               
               
                   
                 423. 
                 Boundary 
               
               
                   
                 501. 
                 Line 
               
               
                   
                 502. 
                 Profile 
               
               
                   
                 503. 
                 Profile 
               
               
                   
                 601. 
                 Line 
               
               
                   
                 602. 
                 Function 
               
               
                   
                 603. 
                 Line 
               
               
                   
                 604. 
                 Line 
               
               
                   
                 801. 
                 Function 
               
               
                   
                 802. 
                 Subtract function 
               
               
                   
                 803. 
                 Line 
               
               
                   
                 804. 
                 Line 
               
               
                   
                 805. 
                 Subsystem 
               
               
                   
                 806. 
                 Servo system 
               
               
                   
                 901. 
                 Receiver 
               
               
                   
                 902. 
                 Lenticular sheet 
               
               
                   
                 903. 
                 Lenticules 
               
               
                   
                 904. 
                 Lenticules 
               
               
                   
                 905. 
                 Lenticules 
               
               
                   
                 906. 
                 Lenticules 
               
               
                   
                 910. 
                 Beam 
               
               
                   
                 911. 
                 Scanline 
               
               
                   
                 912. 
                 Angle 
               
               
                   
                 913. 
                 Sensor 
               
               
                   
                 914. 
                 Line 
               
               
                   
                 915. 
                 Position 
               
               
                   
                 916. 
                 Line 
               
               
                   
                 1001. 
                 Element 
               
               
                   
                 1002. 
                 Angle 
               
               
                   
                 1101. 
                 Stage 
               
               
                   
                 1104. 
                 Collimated bundle 
               
               
                   
                 1106. 
                 Lens 
               
               
                   
                 1108. 
                 Mirror 
               
               
                   
                 1110. 
                 Beam 
               
               
                   
                 1112. 
                 Detector 
               
               
                   
                 1114. 
                 Line 
               
               
                   
                 1116. 
                 Element 
               
               
                   
                 1118. 
                 Line 
               
               
                   
                 2000. 
                 Swath 
               
               
                   
                 2000a. 
                 Swath 
               
               
                   
                 2003a. 
                 Lenticule 
               
               
                   
                 2004. 
                 Beam 
               
               
                   
                 2007. 
                 Detector 
               
               
                   
                 2010. 
                 Lens