Abstract:
A two-parallel-channel reflector (TPCR) with focal length and disparity control is provided. The TPCR is connected to an imaging device, so that an image of a scene is captured to generate a stereoscopic image. The TPCR has two parallel channels that allow the imaging device to generate a left side view image and a right side view image of the shot scene synchronously. Each parallel channel includes an outward reflecting unit and an inward reflecting unit, which are designed to ensure that light rays in the parallel channels are reflected in a collimated and parallel manner. During imaging, a position and an angle of the outward reflecting unit can be adjusted to fulfill the function of controlling the disparity and the focal length.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a two-parallel-channel reflector (TPCR) with focal length and disparity control, and in particular, to a TPCR with focal length and disparity control, having two parallel channels that allow an imaging device to capture a left side view image and a right side view image of a shot scene synchronously and capable of adjusting a position and an angle of an outward reflecting unit according to imaging requirements during imaging to control the disparity and the focal length. 
         [0003]    2. Related Art 
         [0004]    Conventional computer stereo vision uses two or more imaging devices such as two or more cameras to shoot images of the same scene from different view angles. The imaging devices are separated by a suitable distance, like human eyes. When a person views an object, a disparity effect is generated because of a distance between the eyes, thus the image has a stereoscopic impression. Accordingly, after each imaging device respectively performs imaging through analysis and calculation of computer software, the depth of the scene in the picture may be calculated with the principle similar to the human eye disparity, so as to generate images-plus-depth information. Therefore, with the image obtained by each imaging device and the calculated images-plus-depth information, a digital stereo image may be generated. Currently, the relevant conventional technologies include: 
         [0005]    (1) a two-channel multi-view imaging system patented by Andre Redert and Emile Hendriks in 2003, where reference may be made to U.S. Pat. No. 6,643,396 “Acquisition of 3-D Scenes with a Single Hand Held Camera”; and 
         [0006]    (2) a single hand held camera installed on a reflector patented by Pieter O. Zanen, where reference may be made to U.S. Pat. No. 5,532,777 “Single lens apparatus for three-dimensional imaging having focus-related convergence compensation”. 
         [0007]    Referring to  FIG. 1 , in a two-channel multi-view imaging system  1 , a hand held camera  11  is installed on a reflector  12  patented by Pieter O. Zanen. The reflector  12  has two imaging channels (a left imaging channel  121  and a right imaging channel  122 ), and each channel is bounded by two flat reflecting mirrors. As shown in  FIG. 1 , the left imaging channel  121  is bounded by a first center mirror  1211  and a left mirror  1212 , and the right imaging channel  122  is bounded by a second center mirror  1221  and a right mirror  1222 . Light rays L 1  (or captured images) entering the left imaging channel  121  arrive at the left mirror  1212 , are reflected to the first center mirror  1211 , and are then reflected to the camera  11 . Light rays L 2  entering the right imaging channel  122  arrive at the right mirror  1222 , are reflected to the second center mirror  1221 , and are then reflected to the camera  11 . Hence, an image generated by Redert/Hendricks&#39; imaging system  1  at least contains two views of the scene, that is, a left view and a right view. That is, the imaging system  1  can obtain images of different view angles synchronously by using only one camera. However, the two imaging channels of the imaging system  1  are constructed by flat reflecting mirrors, in which the problem that miniaturization cannot be achieved exists.  FIG. 2  is a schematic diagram of optical paths of the conventional imaging system. Referring to  FIG. 2 , the center mirrors ( 1211 ,  1221 ) and the side mirrors ( 1212 ,  1222 ) are all flat, so that, for the purpose of obtaining complete imaging and satisfying a large focal length range during imaging, the sizes of the center mirrors ( 1211 ,  1221 ) and the side mirrors ( 1212 ,  1222 ) should be as large as possible to adapt to the angles of incidence and reflection of the light rays and the images. As a result, the entire dimension of the finished product, for example, the thickness d 1 , is quite large, which not only occupies a large space, but also causes inconveniences in use. On the contrary, if the sizes of the center mirrors ( 1211 ,  1221 ) and the side mirrors ( 1212 ,  1222 ) are reduced, the focal length during imaging is limited. 
         [0008]    An improvement of Redert and Hendriks&#39; approach was patented by Shuzo Seo in 2005, where reference may be made to U.S. Pat. No. 6,915,073 “Stereo Camera and Automatic Convergence Adjusting Device”. In the technology disclosed in this patent, a pivot mechanism is added to the two-channel reflector so that outward mirrors can be rotated about the pivot mechanism. This rotation process is automatically performed when lens of the camera are zoomed. As a result, the focal length of the two-channel reflector can be automatically adjusted. This is an important invention on single-lens, multi-view imaging process. However, unfortunately, due to the fact that flat mirrors are used for both outward reflecting and inward reflecting, this technology cannot adjust the disparity of the reflector either. 
       SUMMARY OF THE INVENTION 
       [0009]    In view of the above problems, the present invention is directed to a TPCR with focal length and disparity control that is capable of being miniaturized and adjusting the disparity and focal length in capturing of an image. 
         [0010]    In order to achieve the above objectives, the present invention uses two outward reflecting units and two corresponding inward reflecting units to construct two imaging channels, so that light and images are reflected in parallel in reflection paths formed between the outward reflecting units and the inward reflecting units. In this way, the thickness of the imaging channel can be greatly reduced, thereby achieving the requirement of miniaturization. Furthermore, in the present invention, due to the characteristics of the parallel reflection paths, the outward reflecting unit is further manufactured to be capable of adjusting the position and angle, so that a distance between the outward reflecting unit and the inward reflecting unit and the angle of the outward reflecting unit are adjusted, thereby achieving the efficacy of adjusting the focal length and disparity in imaging. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The present invention will become fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein: 
           [0012]      FIG. 1  shows a conventional two-channel multi-view imaging system; 
           [0013]      FIG. 2  is a schematic diagram of optical paths of the conventional imaging system; 
           [0014]      FIG. 3  is a schematic constitutional diagram of the present invention; 
           [0015]      FIG. 4  is a schematic diagram (I) of implementation of the present invention; 
           [0016]      FIG. 5  is a schematic diagram (II) of implementation of the present invention; 
           [0017]      FIG. 6  is a schematic diagram of optical paths during implementation of the present invention; 
           [0018]      FIG. 7  shows another preferred embodiment (I) of the present invention; 
           [0019]      FIG. 8  shows another preferred embodiment (H) of the present invention; 
           [0020]      FIG. 9  is a three-dimensional outside view of a finished product of the present invention; 
           [0021]      FIG. 10  shows another preferred embodiment (III) of the present invention; and 
           [0022]      FIG. 11  shows another preferred embodiment (IV) of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]      FIG. 3  is a schematic constitutional diagram of the present invention. As shown in  FIG. 3 , a TPCR with focal length and disparity control  2  is mainly constructed by a left side imaging channel  21 , a right side imaging channel  22 , and a central image inlet  23 . An end of the left side imaging channel  21  and an end of the right side imaging channel  22  are connected to the central image inlet  23 . The left side imaging channel  21  is constructed by a left side image inlet  211 , a left side outward reflecting unit  212 , and a left side inward reflecting unit  213 . The right side imaging channel  22  is constructed by a right side image inlet  221 , a right side outward reflecting unit  222 , and a right side inward reflecting unit  223 . A convex lens  231  is assembled in the central image inlet  23 . As shown in  FIG. 3 , the left side outward reflecting unit  212  and the right side outward reflecting unit  222  are curved reflecting minors, and are used for reflecting light and an image that enter the left side imaging channel  21  and the right side imaging channel  22  in parallel to the left side inward reflecting unit  213  and the right side inward reflecting unit  223 . As shown in  FIG. 3 , after being reflected in parallel to the left side inward reflecting unit  213  and the right side inward reflecting unit  223 , the light and the image are reflected again and are focused through the convex lens  231 , and then pass through the central image inlet  23  and enter an imaging device. 
         [0024]      FIG. 4  is a schematic diagram (I) of implementation of the present invention. As shown in  FIG. 4 , the TPCR with focal length and disparity control  2  may be installed in front of an imaging device  30 . The imaging device may be a single-lens reflex camera or a video camera. After the installation, the central image inlet  23  corresponds to an imaging module  301  of the imaging device  30 , for example, a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS).  FIG. 5  is a schematic diagram (II) of implementation of the present invention. As shown in  FIG. 5 , a scene  40  to be shot is located in front of the TPCR with focal length and disparity control  2 . When an operator shoots the scene (or performs an imaging operation), due to the influence of light rays, images of the shot scene  40  synchronously enter the TPCR with focal length and disparity control  2  through the left side imaging channel  21  and the right side imaging channel  22  respectively. The image entering through the left side image inlet  211  of the left side imaging channel  21  is a left side view image LP 1 . The image entering through the right side image inlet  221  of the right side imaging channel  22  is a right side view image RP 1 .  FIG. 6  is a schematic diagram of optical paths during implementation of the present invention. As shown in  FIG. 6 , when the left side view image LP 1  arrives at the left side outward reflecting unit  212 , is reflected in parallel to the left side inward reflecting unit  213  by the left side outward reflecting unit  212 , is reflected by the left side inward reflecting unit  213 , passes through the convex lens  231  and is focused, and then enters the imaging device  30  through the central image inlet  23 . Moreover, the right side view image RP 1  arrives at the right side outward reflecting unit  222 , is reflected in parallel to the right side inward reflecting unit  223 ; is reflected by the right side inward reflecting unit  223 , passes through the convex lens  231  and is focused, and then enters the imaging device  30  through the central image inlet  23 . Accordingly, the imaging module  301  of the imaging device  30  can synchronously obtain the left side view image LP 1  and the right side view image RP 1 . 
         [0025]      FIG. 7  is another preferred embodiment (I) of the present invention. As shown in  FIG. 7 , the left side outward reflecting unit  212  and the right side outward reflecting unit  222  can be further designed to be a movable adjustment mechanism, so that the left side outward reflecting unit  212  can be adjusted for displacement of a relative distance with respect to the left side inward reflecting unit  213 , and the right side outward reflecting unit  222  can also be adjusted at a relative distance with respect to the right side inward reflecting unit  223 . In this way, when an image capturing operation is performed, a disparity adjustment function is achieved according to the present invention. As shown in  FIG. 7 , under control of an operator, positions of the left side outward reflecting unit  212  and the right side outward reflecting unit  222  may be changed. Displacement adjustment of position (P 1  to P 3  and P 1 ′ to P 3 ′) is shown in  FIG. 7 . The movable adjustment mechanism of the left side outward reflecting unit  212  and the right side outward reflecting unit  222  may be designed to have a function of synchronously adjusting displacement. The movable adjustment mechanism may be of a mechanical type, an electronic type or a combination thereof. 
         [0026]      FIG. 8  is another preferred embodiment (II) of the present invention. As shown in  FIG. 8 , the left side outward reflecting unit  212  (or the right side outward reflecting unit  222 ) of the present invention may be further designed to be an angle deflection adjustment mechanism, so as to enable an operator to adjust the focal length and the disparity during imaging. As shown in  FIG. 8 , the left side outward reflecting unit  212  may be assembled with a rotation shaft  214 , which may be collocated with a second control device (not shown in  FIG. 8 ), so as to enable the operator to operate the control device in the imaging process, so that the left side outward reflecting unit  212  can be deflecting around the rotation shaft  214  as a center to change an angle of the left side outward reflecting unit  212 , thereby achieving the function of adjusting the focal length and disparity in imaging, where an angle Θ formed between the left side outward reflecting unit  212  and the central image inlet may be used as a reference. The structure of the right side outward reflecting unit  222  is the same as that of the left side outward reflecting unit  212 . Deflection angles of the left side outward reflecting unit  212  and the right side outward reflecting unit  222  may be synchronous and with a quantified degree. 
         [0027]      FIG. 9  is a three-dimensional outside view of a finished product of the present invention. As shown in  FIG. 9 , on the physical exterior of the TPCR with focal length and disparity control  2  of the present invention that is assembled on a lens  302  in the front of the imaging device  30 , an assembly portion  24  may be shaped, so that the TPCR with focal length and disparity control  2  can be rapidly assembled on the lens  302 . A first control device  25  may be further assembled, for actuating the movable adjustment mechanism (referring to  FIG. 7 ). When being operated, the first control device  25  can actuate the left side outward reflecting unit  212  and the right side outward reflecting unit  222  to produce displacement, so that the operator can adjust disparity during imaging. A second control device  26  may be further assembled. When being operated, the second control device  26  can actuate the rotation shaft  214  to drive the left side outward reflecting unit  212  and the right side outward reflecting unit  222  to be deflected to change the angles (referring to  FIG. 8 ), so that the operator can adjust the focal length during imaging. The second control device  26  may be a mechanical control device, an electronic control device or a combination for actuating the rotation shaft  214 . 
         [0028]      FIG. 10  is another preferred embodiment (III) of the present invention. As shown in  FIG. 10 , in the TPCR with focal length and disparity control  5 , the left side imaging channel  51  has a left side concave lens  511 , a left side outward flat reflecting unit  512 , and a left side inward curved reflecting unit  513 ; the right side imaging channel  52  has a right side concave lens  521 , a right side outward flat reflecting unit  522 , and a right side inward curved reflecting unit  523 . As shown in  FIG. 10 , in the left side imaging channel  51 , a left side view image LP 1  of an imaged scene is collected by a concave surface of the left side concave lens  511  with a large curvature. After passing through the left side concave lens  511 , the left side view image LP 1  arrives at the left side outward reflecting unit  512  and is reflected in parallel to the left side inward reflecting unit  513 , and is reflected out by the left side inward reflecting unit  513  (and enters an imaging device  30  through a central image inlet). The right side imaging channel  52  has the same function. As shown in  FIG. 10 , the left side concave lens  511  and the left side outward flat reflecting unit  512  in the left side imaging channel  51  may be designed to form a module capable of generating synchronous displacement actions. In this way, during imaging, the left side concave lens  511  and the left side outward flat reflecting unit  512  can be adjusted at a relative distance from the left side inward reflecting unit  513  under control, thereby achieving the function of adjusting the disparity during imaging. 
         [0029]      FIG. 11  is another preferred embodiment (IV) of the present invention. As shown in  FIG. 11 , another feasible embodiment is further proposed, where the original left side inward curved reflecting unit  513  in the left side imaging channel  51  of the preferred embodiment (III) is replaced with a flat mirror capable of generating reflection (that is, a left side reflecting mirror  514  shown in  FIG. 11 ); the original right side inward curved reflecting unit  523  in the right side imaging channel  52  is replaced with a flat mirror capable of generating reflection (that is, a right side reflecting mirror  524  shown in  FIG. 11 ); and a convex lens  53  is further assembled in an optical path reflection direction of the left side reflecting mirror  514  and the right side reflecting mirror  524 . As shown in  FIG. 11 , in the left side imaging channel  51 , a left side view image LP 1  of an imaged scene is collected by a concave surface of the left side concave lens  511  with a large curvature. After passing through the left side concave lens  511 , the left side view image LP 1  arrives at the left side outward reflecting unit  512  to be reflected in parallel to the left side inward reflecting unit  513 , is reflected out by the left side reflecting mirror  514 , is focused by the convex lens  53 , and enters an imaging device  30  through a central image inlet. The right side imaging channel  52  has the same function. 
         [0030]    Based on the above, in the present invention, an outward reflecting module is formed by a curved reflecting mirror or a concave lens collocated with a flat reflecting mirror, so that light can enter the outward reflecting module from outside during imaging. In addition, an inward reflecting module is formed by a curved reflecting mirror or a flat reflecting mirror collocated with a convex lens. The outward reflecting module and the inward reflecting module construct a TPCR, which can synchronously capture a left-view image and a right-view image of a scene into an imaging device and control the disparity and the focal length in an image generation process by adjusting a view distance and direction. In the structure disclosed in the present invention, light rays can be transmitted in parallel in the two parallel channels, so that the view distance and direction can be adjusted. Accordingly, after being implemented, the present invention at least has the following two advantages. 
         [0031]    (1) The light rays are reflected in parallel between the outward reflecting unit and the inward reflecting unit. Regardless of whether a greater or smaller disparity is required, in the present invention, it is only necessary to use an outward reflecting unit and an inward reflecting unit of the same size, so that under the same disparity range condition, the thickness of the finished product of the present invention is less than that of any conventional similar device, and it is estimated that the thickness may be reduced by about ⅔. With the specific miniaturized result, the present invention can be quickly assembled in front of, for example, the lens of the single-lens reflex camera or may be even embedded into, for example, the frame of a display of a computer, which facilitates the application of the present invention to image capturing and 3D imaging. 
         [0032]    (2) The positions of the outward reflecting units can be shifted, and the angles of the outward reflecting units can also be adjusted, so that during the image generation process, the user can implement operations of controlling the disparity and the focal length by using the present invention. 
         [0033]    In sum, after the present invention is implemented accordingly, the objective of providing a TPCR with focal length and disparity control that is capable of being miniaturized and controlling the disparity and the focal length can surely be achieved. 
         [0034]    The above descriptions are merely preferred embodiments of the present invention, but are not intended to limit the implementation scope of the present invention. Any equivalent variations and modifications made by persons skilled in the art without departing from the script and scope of the present invention shall all fall within the patent scope of the present invention.