Abstract:
A binocular kaleidoscope for the purpose of combining the field of repeating patterns associated with kaleidoscopes with stereopsis. A mirror chamber with an object window at the distal end and viewing lenses at the proximal end is utilized, which provides stereopsis covering the entire visual field of both the source material and its reflections. Real depth is provided in an embodiment utilizing physical material such as beads or liquids contained in one or more stacked transparent compartments as the source imagery. Virtual depth is provided in an embodiment utilizing stereoscopic video as the source imagery, in which case a mirrored divider bisects the mirror chamber. The video can be either be previously produced footage or generated in real time by software which can be interactively manipulated by the user in order to change programs or such parameters as color, motion and timing. A handheld device can be used to display the video. The stereoscopic video kaleidoscope described herein may also be adapted for use as a stereoscopic 3D viewer.

Description:
[0001]    This patent application claims priority from U.S. Provisional Patent Application No. 61/298,358, filed on Jan. 26, 2010. 
     
    
     TECHNICAL FIELD 
       [0002]    The following relates to kaleidoscopes, specifically to stereoscopic kaleidoscopes and viewers. 
       BACKGROUND 
       [0003]    Since it was invented by Sir David Brewster in 1815, the kaleidoscope has continued to fascinate generation after generation of children and adults. The ability to peer into the eyepiece of a simple and small device and discover and manipulate a seemingly endless field of ever-changing symmetrical patterns is something that has always had widespread appeal. 
         [0004]    In its most basic form, the kaleidoscope consists of a tube encasing three elongated mirrors creating a triangular column. One end of the column forms an object window abutting a transparent rotating chamber containing an assortment of colorful bits of plastic or glass; this serves as the source material to be viewed and reflected. The other end of the column serves as the eyepiece. When viewed through the eyepiece, the triangular aperture of the object window affords a direct view of the source material behind it, and the surrounding mirrors produce a repeating pattern of multiple reflections of that image. The direct view and the reflections of it combine to produce a field of patterns extending to the edges of peripheral vision. However, since only one eye is afforded this view, the imagery produced is flat, or two-dimensional. 
         [0005]    Several binocular kaleidoscopes in the prior art have introduced binocular viewing into kaleidoscope design. The term “binocular” however only refers to the use of both eyes, and does not necessarily imply stereopsis, or the sensation of depth. If a viewer uses both eyes to view essentially flat subject matter such as a photograph of a car, the amount of depth perceived is obviously limited in comparison to looking at the actual car. The more depth the subject matter has, the more parallax—i.e., the difference in the perceived position of a 3D object when viewed by the left vs. the right eye—there is, and the more depth that can be perceived. Of the previous binocular kaleidoscopes in the prior art none take full advantage of the possibilities of stereopsis. 
         [0006]    In the case of U.S. Pat. No. 4,820,004 (Briskin), no mention is made of dimensional source material, no lenses are suggested to aid in focusing, no claims are made for stereopsis, and little would be possible because of the greatly reduced parallax inherent in the design. In the case of U.S. Pat. No. 5,020,870 (Gray), the source material on the disks or dishes suggested is either essentially flat or are not deep enough to introduce parallax, consequently only the internal reflections would provide any stereopsis. In the case of U.S. Pat. No 5,475,532 (Sandoval et al.), no lenses are suggested to aid in focusing, and the arrangement of mirrors and windows allows for stereopsis only in a version large enough to be able to view through a single window with both eyes, necessitating a substantially larger and unwieldy device, and any subsequent stereopsis would be almost entirely comprised of the internal reflections as opposed to imagery framed by the windows. In the case of Int. Pat. No. 03/083516 (Wallach), no lenses are suggested to aid in focusing, and the only source material suggested are either a flat disk or a flat container, eliminating the possibility of significant parallax. In addition, the arrangement of two triangular cross-sectioned eye channels at an angle to one another could only produce stereopsis in a limited, harlequin-patterned portion of reflections covering only one third of the total viewing area. 
         [0007]    In addition, these binocular kaleidoscopes all rely on physical objects as the source material to be reflected. Another possibility unexplored by them is to utilize stereoscopic imagery or video as the source material. 
         [0008]    Several video kaleidoscopes in the prior art have been proposed, namely: U.S. Pat. No. 4,731,666 (Csesznegi);U.S. Pat. No. 6,062,698 (Lykens); and U.S. Pat. No. 7,399,083 (Bailey et al.). However, these are monocular and/or do not utilize stereoscopic source material, and therefore cannot produce stereoscopic patterns based on the source material. 
         [0009]    Thus advantages of one or more aspects of the present invention are to incorporate source material providing sufficient parallax for significant stereopsis, and stereo viewing of both that source material and its internal reflections covering the entire foveal or central region of vision. In addition to stereopsis, an advantage of binocular viewing over monocular viewing is that small children have difficulty viewing material with one eye rather than two. Other advantages of one or more aspects are to provide for a device that is small, portable, handheld, simple, and inexpensive to manufacture. These and other advantages of one or more aspects will become apparent from a consideration of the ensuing description and accompanying drawings. 
       SUMMARY 
       [0010]    The primary objective of the stereoscopic kaleidoscope described herein is to improve on the visual experience associated with kaleidoscopes by giving it depth and making it more immersive. 
         [0011]    This is achieved by means of a mirror chamber consisting of two or more inwardly reflecting mirrored surfaces lining the interior of a viewing apparatus. This chamber opens to an object window at one end, and the opposing end houses two eyepiece lenses. 
         [0012]    In one embodiment utilizing physical materials such as beads as the source material, the entire viewing field allows for stereopsis. In another embodiment utilizing stereoscopic video as the source, the central vertical column of reflections occupying the field of vision most sensitive to stereopsis will be entirely correct (as will every other column of reflections to either side of the central column). Adjacent alternating columns of reflections will have reverse stereopsis (near and far portions of the image will be reversed), although these columns will appear in peripheral vision, which is not sensitive to stereopsis; consequently, this will not be noticeable while viewing straight ahead. 
         [0013]    In an embodiment utilizing physical materials, the source material can consist of objects such as glass or plastic beads, small broken bits of colored glass, sequins, and/or glitter. These materials are contained in a transparent chamber that may or may not be divided into a series of compartments. The materials can freely move about either dry or suspended in a transparent clear or colored liquid such as water, oil or glycerin. One or more compartments filled with multiple non-mixing insoluble colored liquids may be incorporated, with or without bits of material suspended in them. Compartments without any material in them can also be utilized to serve as dividers or gaps that provide greater depth and separation between those compartments that are filled. The chamber can be physically manipulated, such as being shaken, tilted or rotated, and the material in the chamber can tumble and fall, constantly altering the orientation and physical arrangement of the material observed through the object window. 
         [0014]    In another embodiment utilizing stereoscopic video as the source, the mirror box is separated into two channels, one for each eye, with a two-sided mirror as a divider running from between the eyepiece lenses to the object window. This divider prevents one eye from viewing the image intended for the opposite eye. The source material in this embodiment is side-by-side left and right eye parallel-view stereoscopic video or computer generated imagery. The boundaries of the object window&#39;s openings correspond to the boundaries of the images. 
         [0015]    The stereoscopic video kaleidoscope described herein may also be adapted for use as a stereoscopic 3D viewer. In one embodiment, a stereoscopic 3D viewer is provided for viewing a stereoscopic image having a left side and a right side in a parallel-view format. In another embodiment, a stereoscopic 3D viewer is provided for viewing a stereoscopic image formatted in an over and under manner into top and bottom halves. 
         [0016]    Focus adjustments can be provided to accommodate users with varying visual acuity. Adjustments to inter-ocular spacing can also be made to accommodate a wider range of users. 
         [0017]    A stereoscopic 3D viewer can additionally be provided with straps or other means of mounting it on a user&#39;s head or headgear as to position the viewer before the user&#39;s eyes without requiring the user to use his or her hands to hold the viewer. Sensors in the video playback device, such as a compass, accelerometer, gyroscope and/or GPS could track the position, movement and orientation of the user&#39;s head and correspondingly update the stereoscopic imagery displayed in real time. This allows the user to use the stereoscopic 3D viewer as virtual reality goggles. 
         [0018]    Many other aspects and examples will become apparent from the following disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1A  is a perspective view from the front of an embodiment of a stereoscopic kaleidoscope utilizing physical objects as source material. 
           [0020]      FIG. 1B  is a perspective view from the rear of an embodiment of a stereoscopic kaleidoscope utilizing physical objects as source material. 
           [0021]      FIG. 1C  is an exploded view of an embodiment of a stereoscopic kaleidoscope utilizing with physical objects as source material. 
           [0022]      FIG. 1D  is a side plan view of an embodiment of a stereoscopic kaleidoscope utilizing physical objects as source material. 
           [0023]      FIG. 1E  is a top plan view of an embodiment of a stereoscopic kaleidoscope utilizing physical objects as source material. 
           [0024]      FIG. 1F  is a front plan view of an embodiment of a stereoscopic kaleidoscope utilizing physical objects as source material. 
           [0025]      FIG. 2A  is a perspective view from the front of an embodiment of a stereoscopic kaleidoscope utilizing stereoscopic video as source material. 
           [0026]      FIG. 2B  is an exploded view of an embodiment of a stereoscopic kaleidoscope utilizing stereoscopic video as source material. 
           [0027]      FIG. 2C  is a perspective view from the rear of an embodiment of a stereoscopic kaleidoscope utilizing stereoscopic video as source material. 
           [0028]      FIG. 3A  is a perspective view from above of the front of an embodiment of a stereoscopic 3D viewer utilizing side-by-side parallel-view formatted stereoscopic video. 
           [0029]      FIG. 3B  is a perspective view from below of the front of an embodiment of a stereoscopic 3D viewer utilizing side-by-side parallel-view formatted stereoscopic video. 
           [0030]      FIG. 3C  is an exploded view of an embodiment of a stereoscopic 3D viewer utilizing side-by-side parallel-view formatted stereoscopic video. 
           [0031]      FIG. 3D  is a front plan view of an embodiment of a stereoscopic 3D viewer utilizing side-by-side parallel-view formatted stereoscopic video. 
           [0032]      FIG. 3E  is a top plan view of an embodiment of a stereoscopic 3D viewer utilizing side-by-side parallel-view formatted stereoscopic video. 
           [0033]      FIG. 3F  is a side plan view of an embodiment of a stereoscopic 3D viewer utilizing side-by-side parallel-view formatted stereoscopic video. 
           [0034]      FIG. 4A  is a perspective view of an embodiment of a stereoscopic 3D viewer utilizing over/under formatted stereoscopic video. 
           [0035]      FIG. 4B  is a perspective cutaway view of an embodiment of a stereoscopic 3D viewer utilizing over/under formatted stereoscopic video. 
           [0036]      FIG. 4C  is an exploded view of an embodiment of a stereoscopic 3D viewer utilizing over/under formatted stereoscopic video. 
           [0037]      FIG. 4D  is a front plan view of an embodiment of a stereoscopic 3D viewer utilizing over/under formatted stereoscopic video. 
           [0038]      FIG. 4E  is a top plan view of an embodiment of a stereoscopic 3D viewer utilizing over/under formatted streoscopic video. 
           [0039]      FIG. 4F  is a front plan cutaway view of an embodiment of a stereoscopic 3D viewer utilizing over/under formatted stereoscopic video. 
           [0040]      FIG. 4G  is a side plan cutaway view of an embodiment of a stereoscopic 3D viewer utilizing over/under formatted stereoscopic video. 
           [0041]      FIG. 4H  is a diagrammatic side cutout view of the arrangement of the mirrors which form the optics for the viewer. 
       
    
    
     DETAILED DESCRIPTION 
       [0042]    One embodiment of the stereoscopic kaleidoscope utilizing physical objects for source material is illustrated in  FIGS. 1A-1F . A mirror box  11  is comprised of four inward reflecting planar mirrored surfaces. At the viewing end of the mirror box  11 , the top and bottom surfaces should be wide enough so as not to impede the viewer&#39;s peripheral view of the interior reflections. The top and bottom surfaces preferably form trapezoids, converging to a narrower width at an opening  13 , which forms an object window. The mirror box  11  can be assembled from four separate reflective surfaces, preferably first surface mirrors, or from a single molded or vacuum formed plastic box that has a mirrorized interior. The top and bottom of mirror box  11  can either be parallel or at a slight angle to the horizontal to one another. Affixed to the mirror box  11  in front of the object window  13  is a transparent cylindrical tube or collar  14 , preferably made out of plastic. The diameter of the interior walls of the collar  14  is the same as or wider than the width of the object window  13 . 
         [0043]    A source material chamber  15  is a cylindrical tube, capped or sealed at both ends, preferably made out of transparent plastic. The interior of the chamber  15  forms a single compartment, or has clear dividers  16 , preferably made out of plastic, which separate the interior into two or more compartments,  17   a,    17   b,  and  17   c.    
         [0044]    The exterior diameter of chamber  15  is slightly less than that of the interior diameter of collar  14  so as to rotate freely when inserted. A portion of chamber  15  is exposed so as to allow manual rotation of it by the user. This can be accomplished by having chamber  15  extend beyond the length of collar  14  as shown in  FIGS. 1D &amp; 1E , in which case it can be retained by a lip on the interior of the end of collar  14  and a corresponding groove on the exterior of chamber  15 . Alternately, collar  14  can entirely enclose chamber  15  and be capped, in which case collar  14  can have openings in it on opposing sides large enough to allow for manipulation of chamber  15  with a thumb and fingers. 
         [0045]    Compartments  17   a,    17   b,  and  17   c  are filled with an assortment of beads, sequins, glitter, colored non-soluble non-mixing liquids, or other small bits of material which can freely move about when the chamber  15  is manipulated by the user. These objects can reside dry in the compartments  17   a,    17   b,  and  17   c  or be suspended in clear or colored transparent liquids such as water, oil or glycerin. As shown in side view  FIG. 1D , when multiple compartments are filled with objects that are not transparent enough to allow for sufficient viewing through them to the materials in end compartment  17   c,  the compartment  17   a  closest to object window  13  is filled with the least amount of material, and subsequent chambers are filled with progressively greater amounts of material, culminating in the end compartment  17   c  which is filled with the greatest amount of material. 
         [0046]    Viewing lenses  10  aid in focusing on the materials in the chamber  15  and are preferably made out of optically transparent plastic. The viewing lenses  10  preferably have a focal length such that their optimum focus point resides at or just beyond the object window  13 , and should be far enough apart and of a sufficient diameter so as to accommodate a range of inter-ocular distances from children to adults. Top and bottom housings  12  are affixed to the mirror box  11  so as to support the collar  14 . 
         [0047]    Another embodiment of the stereoscopic kaleidoscope can incorporate a motor assembly, controlled by one or more buttons or a toggle button or switch, which can rotate the chamber  15  in either a clockwise or counter-clockwise direction according to which button is pressed. The button or buttons can be pressure sensitive so that increasing the pressure applied will increase the speed of the rotation. The motor can rotate chamber  15  by means of friction applied by a wheel in contact with it, preferably made out of rubber, or by a geared wheel, which could engage corresponding gears around chamber  15 &#39;s outer perimeter. 
         [0048]    The stereoscopic kaleidoscope can feature a much longer source material chamber  15  than illustrated in the figures to provide greater separation between compartments and an increased perception of depth. In this case the chamber could be conical rather than cylindrical with a wider diameter at the end opposite the object window, so as to ensure that all of the chambers, including those farthest away from the viewer, cover the entire field of view. 
         [0049]    Yet another embodiment of the stereoscopic kaleidoscope can incorporate lighting elements such as LED lights into either the source material chamber or into the interior of the mirror box. These lights could flash or change colors in a pre-programmed sequence. In the mirror box, LEDs could be arranged spaced closely together in rows lining the four corners and/or along a rod positioned in the center of the box from the object window to between the eyepiece lenses. The LEDs can be programmed to fire in sequence so as to produce an animated effect simulating motion, especially motion toward or away from the viewer. 
         [0050]    A further embodiment of the stereoscopic kaleidoscope can incorporate another object or source material compartment in the interior of the mirror box, separated from the source material chamber  15 . Slots could be cut in the top and bottom of the mirror box to accommodate this compartment. This compartment could be attached to the source material chamber  15  by means of a rod through its center so it would rotate with the others. 
         [0051]    The stereoscopic kaleidoscope can feature mechanism whereby chamber  15  can move towards and away from the viewer, preferably oscillating back and forth as it is rotated. 
         [0052]    In one embodiment of the stereoscopic kaleidoscope, the source material chamber  15  can feature an “infinity mirror.” The chamber  15  would have a reflective surface, preferably a first surface mirror, at its back facing the viewer, a two-way mirror at its front closest to the object window  13 , and be filled with fluorescent colored objects such as beads. These beads could be illuminated by one or more UV LEDs around its perimeter. 
         [0053]    In another embodiment the stereoscopic kaleidoscope, the top and bottom mirrors of the mirror box could be hinged where they form the object window instead of fixed so they could assume a variety of angles with respect to one another. This results in the apparent shape of the reflections created changing from a straight vertical wall when the mirrors are parallel, to a curved surface bowing away from the viewer at the object window when the mirrors are angled with a greater separation at the eyepiece lens side. A mechanism, for example, incorporating rods and gears could link the manual rotation of the source material chamber to an oscillating variation of angles so that the apparent shape of the reflections changes over time. 
         [0054]    Another embodiment of the stereoscopic kaleidoscope utilizes stereoscopic video as source material and is illustrated in  FIGS. 2A-2C . A mirror box  27  seen in  FIGS. 2B and 2C  is comprised of four inward reflecting planar mirrored surfaces, preferably first surface mirrors. An eyepiece divider  28  bisects and runs the length of the mirror box  27 , and has outward reflecting mirror surfaces on both sides. The mirror box  27  is rectilinear, and the length and height of the openings correspond to the exact dimensions of the video material. The mirror box  27  is contained with housing  22 , which incorporates panels  23 . These panels  23  have indentations  30  which correspond to the narrower outer dimensions of the front of a handheld video playback and computing device  26 , such as Apple&#39;s iPhone®, in order to allow for correct vertical positioning, alignment and stabilization with it. The user can visually align the sides of the stereoscopic kaleidoscope horizontally to the video screen  29  on the handheld video playback and computing device  26 . A lens box  24  slides over housing  22  and is loose enough to allow for repositioning for focus adjustments but tight enough so as not to fall off. The viewing lenses  25  have a focal length focal length sufficient so that their optimum focus point resides at the screen of the handheld video playback and computing device  26 . 
         [0055]    The housing  22  and the lens box  24  can be made out of various materials such as injection modeled plastic, plastic sheeting, or folded cardboard. The panels  23  can have pre-scored removable notches at regular intervals on either side of the indentations  30  so as to allow the user to increase the size of the indentations  30  to allow for alignment with a variety of widths of handheld video playback and computing devices. 
         [0056]    Stereoscopic imagery is formatted for the handheld video playback and computing device  26  in side-by-side, parallel-view format. Parallel-view refers to the placement of the left image on the left side of the screen and the right image on the right side of the screen. The two images are of the same scene but are from two slightly different points of view, and are displayed on video screen  19 , as shown in  FIG. 2B . The first image, indicated by the reference numeral  20 , shows a scene from a left eye&#39;s point of view. The second image, indicated by the reference numeral  21 , shows the same scene from a right eye&#39;s point of view. The amount of distance between these two points of view typically corresponds roughly to the average inter-ocular distance, but can be exaggerated to increase parallax and thus the stereoscopic effect. 
         [0057]    The material viewed can include a wide variety of pre-existing stereoscopic content, or be generated in real time, in which case the viewer could interact with the imagery produced by software in a variety of fashions, including pushing buttons, interacting with a touch screen, making noise, or tilting, rotating, or shaking a device that has an accelerometer and/or a compass. In addition, the user&#39;s physical location and orientation could be tracked by accelerometer, compass, and/or GPS in the device. The software could respond to this input by changing the program or by altering visual aspects of the imagery such as position, size, color, shape, speed, frequency, or apparent depth. 
         [0058]    Another embodiment of the stereoscopic video kaleidoscope may be provided with horizontal panels in addition to vertical panels  23 , incorporating indentations that correspond to the wider outer dimensions of the front of the handheld video playback and computing device  26  so that the user does not have to align the two visually. Or instead of panels, a container or other holder can be provided to maintain the video playback device  26  such that it is aligned with the mirror box  27  and such that the user does not have to hold it separately. 
         [0059]    The stereoscopic video kaleidoscope described herein may also be adapted for use as a stereoscopic 3D viewer. 
         [0060]    One embodiment of the 3D hand-held video viewer is illustrated in  FIGS. 3A-3F  and is used with side-by-side parallel-view formatted stereoscopic imagery. Viewing chamber  31  houses eyepiece lenses  34  at the front end and is open at the back and on the bottom. Attached to the viewing chamber  31  is a holder  32  with an opening at the top into which a hand-held video playback and computing device  38  such as Apple&#39;s iPhone® can slide. A shell  37 , preferably made out of foam rubber, lines the sides and back of the holder  32  so as to seat the hand-held device  38  snuggly and center its alignment to the eyepiece lenses  34 , and also allow for a variety of devices with differing dimensions to be accommodated. Thumb notch  36  facilitates easy removal of the device. Set into the viewing chamber  31  is a nose notch  33 . 
         [0061]    Set into the front surface of the hand-held video playback and computing device  38  is a video screen or monitor  39 , which may be a touch-screen. The opening at the back of the viewing chamber  31  corresponds to the dimensions of the video screen  39 . The focal length of the eyepiece lenses  34  are such that their optimum focus point corresponds to the distance to the video screen  39 . 
         [0062]    An eye divider  35  ensures that the left eye only sees left image  40  and the right eye only sees right image  41 . The bottom of viewing chamber  31  is open to allow finger-tip access to controls such as buttons or a touch screen on the hand-held video playback and computing device  38 . 
         [0063]    Stereoscopic imagery is formatted for the hand-held video playback and computing device  38  in side-by-side, parallel-view fashion. Parallel-view refers to the placement of the left image on the left side of the screen and the right image on the right side of the screen. The two images are of the same scene but are from two slightly different points of view, and are displayed on video screen  39 . The first image, indicated by the reference numeral  40  in  FIG. 4C , shows a scene from a left point of view. The second image, indicated by the reference numeral  41 , shows the same scene from a right point of view. The amount of distance between these two points of view typically corresponds roughly to the average inter-ocular distance, but can be exaggerated for effect. 
         [0064]    The material viewed can include a wide variety of pre-existing stereoscopic content, or be generated in real time such as with video games, in which case the viewer could interact with the imagery. In the case of video games, the user could control the game play produced by software in a variety of fashions, including pushing buttons, interacting with a touch screen, making noise, or tilting, rotating, or shaking a device that has an accelerometer and/or a compass. In addition, the user&#39;s physical location and orientation could be tracked by accelerometer, compass, and/or GPS in the device and figure into the game play, particularly in online multi-player games. 
         [0065]    In addition to the device being hand held, the device could be mounted to a stand so that it might be placed on a table or other surface, or be mounted to straps or a hat to be worn on the viewer&#39;s head so as to position it to the viewer&#39;s eyes without requiring the use of the viewer&#39;s hands. If the viewer wears the device on his or her head, sensors in the hand-held video playback and computing device  38  such as a compass, accelerometer, gyroscope and/or GPS could track position and orientation of the user&#39;s head and correspondingly update the point of view of imagery generated in real time. This would effectively turn the device into very inexpensive virtual reality goggles, and provide for a truly immersive interactive experience. 
         [0066]    Another embodiment of the 3D hand-held video viewer is illustrated in  FIGS. 4A-4H  and is intended for over/under formatted stereoscopic imagery. Housing front  51  and housing back  52  are attached and form the main body of the device  49  with an opening at the top  50  into which a hand-held video playback and computing device  60  such as Apple&#39;s iPhone® can slide. An opening  53  may be provided for the user to operate the Home button of the iPhone®. Left eyepiece lens  54 L and right eyepiece lens  54 R are set into corresponding holes in housing front  51 . A shell  59 , preferably made out of foam rubber, lines the sides and back of the housing back  52  so as to seat the hand-held device  60  snuggly and center its alignment to the eyepiece lenses  54 , and also allow for a variety of devices with differing dimensions to be accommodated. 
         [0067]    A mirror assembly is comprised of four planar reflecting surfaces  55 - 58 , preferably front-surface mirrors. A left front mirror  55  is located on the left side of housing front  51  at an angle to the vertical. The left front mirror  55  is optically aligned with the left eyepiece lens  54 L so that it can be viewed through the left eyepiece lens  54 L. A left rear mirror  56  is located in the left side of housing front  51  at an angle to the vertical and is optically aligned with the left front minor  55 . The reflecting faces of the mirrors  55  and  56  are facing each other and parallel with each other as shown in  FIGS. 4G and 4H . A right front mirror  57  is located on the right side of housing front  51  at an angle to the vertical. The right front mirror  57  is optically aligned with the right eyepiece lens  54 R so that it can be viewed through the right eyepiece lens  54 R. A right rear mirror  58  is located on the right side of housing front  51  at an angle to the vertical and is optically aligned with the right front mirror  57 . The reflecting surfaces of the mirrors  57  and  58  are facing each other and are parallel with each other as shown in  FIGS. 4G and 4H . 
         [0068]    The optics of this embodiment are diagrammatically illustrated in  FIG. 4H  and are designed for optically combining two stereoscopically complementary images displayed on the screen  61  of the hand-held video viewer  60 . The images  62  and  63  are arranged in the same vertical plane with the image  63  directly above the image  62  as shown in  FIGS. 4B ,  4 C and  4 H. The hand-held video monitor  60  is positioned in the main body  49  so that the right rear mirror  58  is in optical alignment with the upper right-eye image  63  and the left rear mirror  56  is in optical alignment with the lower left-eye image  62 . The optical path of the first image  63  extends through the area of dot and dashed line  66  to the reflective surface of the right rear mirror  58 . The image  63  is reflected from the reflective surface of the mirror  58  to the reflective surface of the mirror  57  extending along a path which is bounded by the dot and dashed lines  67 . The image  63  is reflected a second time from the reflective surface of the right front mirror  57  through the right eyepiece lens  54 R along the path which is bounded by the dot and dashed lines  68 R to a right eye position  70 R. The optical path of the second image  62  extends through the area of dot and dashed line  64  to the reflective surface of the left rear mirror  56 . The image  62  is reflected from the reflective surface of the mirror  56  to the reflective surface of the mirror  55  extending along a path which is bounded by the dot and dashed lines  65 . The image  62  is reflected a second time from the reflective surface of the left front mirror  55  through the left eyepiece lens  54 L along the path which is bounded by the dot and dashed lines  68 L to a left eye position  70 L. 
         [0069]    As shown in  FIGS. 4G and 4H , front right mirror  57  extends forward, beyond the optical path bounded by the dot and dashed lines  67  that it is reflecting, so that it&#39;s front edge resides in the plane formed by left rear mirror  56 . This blocks right eye  70 R from viewing any portion of the left eye image  62 . Similarly, front left mirror  55  extends forward, beyond the optical path bounded by the dot and dashed lines  65  that it is reflecting, so that it&#39;s front edge resides in the plane formed by right rear mirror  58 . This blocks left eye  70 L from viewing any portion of the right eye image  63 . 
         [0070]    For both the stereoscopic kaleidoscope and the stereoscopic 3D viewer embodiments, focus adjustments can be provided to accommodate users with varying visual acuity. In addition, adjustments to inter-ocular spacing can also be made to accommodate a wider range of users. 
         [0071]    The above disclosure provides examples and aspects relating to various embodiments within the scope of claims, appended hereto or later added in accordance with applicable law. However, these examples are not limiting as to how any disclosed aspect may be implemented, as those of ordinary skill can apply these disclosures to particular situations in a variety of ways.