Abstract:
Disclosed is a three dimensional image display method and some application structures. The three dimensional display method employs one piece of flat mirror to separate an observer&#39;s right and left eyes while flipping one image, either right or left, to overlay with another to render a vivid three dimensional image. The method does not need eyeglasses, does not need to see through any optical elements, has no limit to the field of view, and is the most nature method for observers to view a three dimensional image just as to view the real world with naked eyes.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to a stereo image display method, and more particularly, to a method capable of displaying a stereo image of a type which does not require the use of stereo viewing spectacles or any other kinds of optical elements, but gives the highest quality three dimensional effect with most natural observation way and lowest cost as oppose to current 3D image display methods. 
         [0003]    2. Description of the Prior Art 
         [0004]    Three dimensional photograph, or in other words, to record and display the three dimensional world with high quality and convenient equipment has been a long time dream for decades. Holographic technology and stereo imaging technology are the major technologies that have been developed for this purpose. Holographic technology can record every angle of an object and display the original object with lossless information. Unfortunately, because of the sophisticate demands on recording and display conditions, hologram has only limited applications so far. On the other hand, stereo imaging method record only two adjacent images of an object from one particular angle and then display the two images to an observer&#39;s left and right eyes respectively to reproduce a vivid three dimensional image of the original object in one particular angle. This method is gaining more and more applications because it can achieve a vivid three dimensional display without sacrificing the high quality of a traditional two dimensional color picture. 
         [0005]    The easiest way to observe a stereo image is to arrange the two images side by side and viewers can intentionally focus two eyes to the two images either parallelly or crossingly. The problem with this easy-to-use method is that the viewers&#39; eyes have to be trained to be able to focus to some empty spot with intension, which is not natural to observers. 
         [0006]    Another method to observe a stereo image is to use a stereoscope or any other binocular or head mount type of optical system to display two images to left and right eyes respectively. The expensive, bulky stereoscope system has limited field-of-view, hence is mainly used in laboratory. The head mounted system also has limited field-of-view, and is inconvenient for general users, so they are mainly used for training systems. 
         [0007]    The third method to observe a stereo image is to use eyeglasses, such as passive filters like color filters or polarizes, or active eyeglass shutters, to direct the left and right images to the observer&#39;s left or right eye respectively. The passive polarizer eyeglass method has been successfully used in three dimensional theaters, and it is expected that most of the theaters will be in this type of three dimensional format in the near future. The active eyeglass shutter method is mainly used for three dimensional TV. The major drawback of all these eyeglass based applications is the inconvenience of eyeglasses. Besides, the images have to be color coded or the sources have to be maintained as polarized light. 
         [0008]    The fourth method to observer a stereo image is to use a Lenticular sheet aligned in front of the interlaced images. The lenticular lens can direct the left and right images to the observer&#39;s corresponding eyes. This method sacrificed the picture quality with the interlacing process and the lenticular lens abbreviations. It also renders an unnatural image view to observers because of the fact that viewers are observing “diffracted images through the lenticular lens” other than directly reflected images as human eyes are used to. 
         [0009]    With three dimensional digital camera coming available and more and more three dimensional videos become available, there is a need to have a three dimensional display method which should be able to display three dimensional images as high quality as traditional two dimensional color pictures, it should be convenient, no eyeglasses needed, no intentional focus training needed, no limit on field of view, not seeing through any optical element or systems, it should be cost effective and fit for public applications. This is what this invention addresses. 
       SUMMARY OF THE INVENTION 
       [0010]    This invention is a low-cost easy-to-use stereo image display method to let an observer to view stereo images in the most natural way just as viewing the actual world with naked eyes. The invented stereo image display method employs a regular flat mirror to overlay the left or the right stereo image to another, so that the observer&#39;s left and right eyes can only observe the corresponding images in a natural observation way. This stereo image display method renders the best three dimensional effects because it does not require any spectaculars or any other optical systems, it does not require intentional eye focus training, observers see the three dimensional image by viewing regular high quality two dimensional color pictures with naked eyes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1 . Shows one embodiment of the three dimensional image display method, which utilize a flat mirror to reflect the left image to overlay to the right image. The left image, which is the horizontally flipped image of the original left image, is herein the reference image. 
           [0012]      FIG. 2 . Shows another embodiment of the three dimensional image display method, which utilize a flat mirror to reflect the right image to overlay to the left image. 
           [0013]      FIG. 3 . shows another embodiment of the three dimensional image display method, which utilize two flat mirrors to reflect both left and right images and overlay them in the middle. Both images are horizontally flipped. 
           [0014]      FIG. 4 . shows one embodiment of the three dimensional image display method. The left and right images are assembled like a book. The flat mirror is used to reflect the left images to overlay to the right images. 
           [0015]      FIG. 5 . shows another embodiment of the three dimensional image display method. The left and right images are assembled like a book. The flat mirror is used to reflect the right images to overlay to the left images. 
           [0016]      FIG. 6 . shows another embodiment of the three dimensional image display method. The left and right images are assembled like a book. Two flat mirrors are used to reflect both left and right images and overlap them in the middle. 
           [0017]      FIG. 7 . shows one embodiment of the three dimensional image display method. The left and right images are displayed on any display devices such as computer monitors, TV monitors, digital picture frames, digital book reader, gaming device screens, or cell phone screens. A flat mirror is used to reflect the left display device to overlay to the right display device. 
           [0018]      FIG. 8 . shows one embodiment of the three dimensional image display method. The left and right image display devices are the same as that in  FIG. 7 . A flat mirror is used to reflect the right display device to overlay to the left display device. 
           [0019]      FIG. 9 . shows another embodiment of the three dimensional image display method. The left and right image display devices are the same as that in  FIG. 7 . Two flat mirrors are used to reflect both left and right display devices and overlap them in the middle. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The three dimensional display method invented here is using a flat mirror to flip one of the two stereo images, left or right, to overlay with another, so the observer&#39;s left and right eyes will see the overlapped left and right images respectively, and hence will perceive a vivid three dimensional image of the original object just as viewing the actual object. This three dimensional display method does not need eyeglasses, does not need intentional eye focus training, does not need to see through any optical elements or systems, has no limit to field of view, it renders the best three dimensional effect without sacrificing the high quality of the images. This convenient method is also cost effective and suitable for various public applications, such as 3D books, 3D exhibitions, 3D monitors, just to name a few. 
         [0021]      FIG. 1  shows one embodiment of a three dimensional exhibition display. A flat mirror  13  is inserted between two display boards  11  and  12 . The angle between the mirror and the two display boards is α ( 15 ), which is around 60 degrees. Wires  14  are used to fix these angles around 60 degrees. Other fixtures such as corner guard can be used to fix these angles in stead of wires. Display board  11  holds the horizontally flipped image of the original left image  11   b  as a reference image, display board  12  hold the original right image  12   b.  The flat mirror  13  reflect the image  11   b  to overlap with the right image  12   b,  so the observer&#39;s ( 17 ) left eye will only see the mirrored image of  11   b,  while right eye will only see the right image  12 . This parallax renders a vivid three dimensional image  16  to the observer  17 . 
         [0022]      FIG. 2  shows another embodiment of a three dimensional exhibition display. The structure is similar to  FIG. 1 , except that the mirror  23  is on the right side, and the image  22   b  is the reference image, which is the horizontally flipped image of the original right image, while the left image  21   b  is the original left image. The observer ( 27 )&#39;s left eye will only see the original left image  21   b,  while right eye will only see the mirror reflected image of the reference image  22   b,  this parallax renders a vivid three dimensional image  26  to observer  27 . 
         [0023]    Although it is not illustrated here, but the mirror of both  FIG. 1  and  FIG. 2  can be a double sides mirror instead of a single side mirror. In this case, if the observer is facing the left side image, the right side image will be the reference image, and this will be the same case as illustrated in FIG. l. While if the observer is facing the right side image, the left side image will be the reference image, and this will be the same case as that illustrated in  FIG. 2 , except that the observed three dimensional image is the mirror image as that of when the observer facing the left image. 
         [0024]      FIG. 3  shows another embodiment of the three dimensional exhibition display. In this embodiment, two pieces of flat mirror is assembled with the left side display board and right side display board with angle α ( 35 ), which is around 60 degree. Both the left image  31   b  and the right image  34   b  are reference images and they are the horizontally flipped images of the original left and right images. The two mirrors reflect the two reference images and overlap them in front of the observer  38 , so the observer&#39;s left eye will see only the reflected left reference image  31   b,  and the observer&#39;s right eye will only see the reflected right reference image  34   b,  this parallax then renders the high quality three dimensional image  37  to the observer. All the wires  36  are used to fix the angles α at about 60 degrees. Other fixtures such as 60 degree corner guard can also be used to fix the angle α and replace the wires  36 . 
         [0025]      FIG. 4  shows one embodiment of the three dimensional book. The three dimensional structure is similar to that of  FIG. 1 , where a left side mirror is used. The main difference is that  FIG. 4  shows the structure that assembled like a book, which can be used but not restricted to picture books, photo albums, product menus, etc. Book pages or photo pockets  46  hold the horizontally flipped left images as reference images. It is bound with  41  using wire  46   b.  While pages or photo pockets  47  hold the corresponding right images, and is bound with  42  using wire  47   b.  Pages  46  and  47  can also be wire bound on the top or the bottom. It is obvious that pages  46  and  47  have to be flipped correspondingly to have the same left and right image pairs at the same time. Wires  44  are used to fix the angle α ( 45 ) around 60 degrees. Again, other kinds of 60 degree corner guard can be used to replace the wires. 
         [0026]      FIG. 5  shows another embodiment of the three dimensional book. The three dimensional structure is similar to that of  FIG. 2 , where a right side mirror is used. Again, the main difference is that  FIG. 5  shows the structure that assembled as a book. Book pages or photo pockets  57  hold the horizontally flipped right images as reference images. It is bound with  52  using wire  57   b.  While pages or photo pockets  56  hold the corresponding left images, and is bound with  51  using wire  56   b.    FIG. 6  shows another embodiment of the three dimensional book. The three dimensional display structure is similar to that of  FIG. 3 , except that here it is assembled as a book. 
         [0027]      FIG. 7  shows one embodiment of the three dimensional display unit. The structure is similar with that in  FIG. 1 , except that the display devices  71  and  72  are computer monitors, digital picture frames, digital book readers, TV monitors, gaming device screen, cellular phone screen, or any other electrical display devices, etc.  FIG. 8  shows another embodiment of the three dimensional display unit. The structure is similar with that in  FIG. 2 . The display devices  81  and  82  are the same as  71  and  72  in  FIG. 7 . The mirrors in  FIG. 7  and  FIG. 8  can be double sided mirror instead of single side. The wires  74  and  84  can also be replaced with other fixtures such as 60 degree corner guard, or just arrange the display devices and the mirrors at the fixed 60 degree angle.  FIG. 9  shows yet another embodiment of the three dimensional display unit. The display structure is similar as that in  FIG. 3 . The display devices  91  and  94  are the same as  71  and  72  in  FIG. 7 . Wires  96  can also be replaced with any other fixtures to fix the angle α ( 95 ) around 60 degrees. 
         [0028]    It is noticed that all the illustrated display structures are having the mirrors and the image boards or display devices connected together. But this is not a necessary condition, in other words, the mirrors and the image boards or the display devices can be arranged separately, if only that the perceived images are overlapped together in front of the observer with parallax, then the observer can see the vivid three dimensional image. 
         [0029]    It is also noticed that viewers have the flexibility to choose to view three dimensional or two dimensional images easily. This is especially convenient to design engineers. And moreover, by adjusting the parallax, or the horizontal relative positions of the left and right display units, or the image positions on the display units, the depths of the three dimensional image can be adjusted. 
         [0030]    While these particular embodiments have been described in this disclosure, alternative embodiments are possible. Furthermore, it is noticed that although the disclosed imaging systems are described as being integrated into “books, exhibition displays, computer monitors, etc.” it is to be understood that it is not intended to limit the applications of the imaging systems to these applications. Instead, applicant is generally referring to apparatus that can use regular mirror or mirrors to reflect one or both of the left and right images to overlap together to form the parallax to render a three dimensional image, regardless of the particular configuration of the apparatus or applications.