Abstract:
A three-dimensional image capture apparatus includes a single lens module, an X-cube beam-splitting prism, two image sensors and a parallax processor. The beam-splitting prism includes a first transflective surface and a second transflective obliquely intersecting the first transflective surface. The first transflective surface is configured for reflecting light from a first viewing angle of an object through the lens module toward a first direction. The second transflective surface is configured for reflecting light from a second viewing angle of an object through the lens module toward an opposite second direction. The image sensors are configured for respectively detecting the light reflected by the first and second transflective surfaces, and generating parallax image signals. The parallax processor is configured for processing the parallax image signals from the image sensors to generate a 3D image.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to a three-dimensional (3D) image capture apparatus. 
     2. Description of Related Art 
     Currently, image capture apparatuses have become widely used in a variety of consumer electronic devices, such as notebook computers, personal digital assistants, cellular telephones, etc. In the meantime, there is an increasing demand for improving image quality, which essentially depends on the quality of the lens module of the image capture apparatus. That is, a lens module with high image quality is desired. 
     A typical 3D image capture apparatus includes two lens modules, two image sensors, and a parallax processor. The two lens modules are horizontally arranged, simulating two eyes of human being, and simultaneously capture parallax images of an object. The images captured by the two lens modules are then respectively detected by the two image sensors. Finally the parallax images detected by the two image sensors are synthesized by the parallax processor, thereby forming 3D images. However, the two lens modules may increase the volume and cost of the 3D image capture apparatus. 
     Therefore, there is a need for a 3D image capture apparatus with a single lens module, to overcome the above mentioned limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the views. 
         FIG. 1  is a schematic, isometric view of a 3D image capture apparatus according to a first exemplary embodiment. 
         FIG. 2  is similar to  FIG. 1 , but showing a light path of the 3D image capture apparatus of  FIG. 1 . 
         FIG. 3  is a schematic, isometric view of a 3D image capture apparatus according to a second exemplary embodiment. 
         FIG. 4  is a schematic, isometric view of a 3D image capture apparatus according to a third exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a 3D image capture apparatus  100  according to a first exemplary embodiment includes a light guiding system  10 , a lens module  12 , a beam-splitting prism  14 , two image sensors  16  and a parallax processor  18 . 
     The light guiding system  10  includes a first light guiding pipe  102 , a second light guiding pipe  104 , two third light guiding pipes  106 , two fourth light guiding pipes  108 , a first mirror  110 , and two second mirrors  112 . One end of the first light guiding pipe  102  is connected to one end of the second light guiding pipe  104 . The first light guiding pipe  102  extends perpendicularly to and is in communication with the second light guiding pipe  104 . The other end of the second light guiding pipe  104  is connected to one end of each third light guiding pipe  106 . The two third light guiding pipes  106  extend perpendicularly to and are in communication with the second light guiding pipe  104 . The two third light guiding pipes  106  extend opposite to each other from the end of the second light guiding pipe  104 . The other ends of the two third light guiding pipes  106  are respectively connected to one end of each fourth light guiding pipe  108 . The fourth light guiding pipes  108  extend perpendicularly to and are in communication with the corresponding third guiding pipes  106 . In this embodiment, the fourth light guiding pipes  108  extend parallel with each other, and are arranged at a same side of the third light guiding pipes  106 . The fourth light guiding pipes  108  each define an opening at the other end thereof. 
     The lens module  12  focus ambient light and transmits the light to the light guiding system  10 . The lens module  12  is positioned in the first light guiding pipe  102 . The lens module  12  has a light incident opening at an open end of the first light guiding pipe  102  away from the second light guiding pipe  104 . The lens module  12  has an optical axis parallel with the extension axis of the first light guiding pipe  102 . 
     The first mirror  110  is in the light path of the 3D image capture apparatus  100  at a first intersection of the first light guiding pipe  102  and the second light guiding pipe  104 , guiding the light transmitting from the first light guiding pipe  102  to the second light guiding pipe  104 . The first intersection includes a first slanted inner surface  101 . The first mirror  110  contacts the first slanted inner surface  101 . In this embodiment, the first mirror  110  has a first reflecting surface  110   a  inclined about 45 degrees with respect to both of the extension axes of the first light guiding pipe  102  and the second light guiding pipe  104 . The second mirrors  112  are respectively in the light path of the 3D image capture apparatus  100  at two second intersections of the third light guiding pipes  106  and the corresponding fourth light guiding pipes  108 , guiding the light transmitting from the third light guiding pipes  106  to the corresponding fourth light guiding pipes  108 . Each second intersection includes a second slanted inner surface  103 . The second mirror  110  contacts the corresponding second slanted inner surface  103 . In this embodiment, the second mirror  112  has a second reflecting surface  112   a  inclined about 45 degrees with respect to both of the extension axes of the corresponding third light guiding pipe  106  and the corresponding fourth light guiding pipe  108 . 
     The beam-splitting prism  14  is located in a boundary among the second light guiding pipe  104  and the two third light guiding pipes  106 . The beam-splitting prism  14  is cuboid-shaped, and includes two transflective surfaces  142  intersected each other, thereby forming an X-shaped structure. The transflective surfaces  142  have both of a reflective property and a transmitting property. The intersection of the two transflective surfaces  142  is perpendicular to the extension axis of the second light guiding pipe  104 , and is also perpendicular to the extension axes of the third light guiding pipes  106 . The transflective surfaces  142  are slanted to each other. That is, the transflective surfaces  142  are not perpendicular or parallel with each other. The inclined angles between the extension axis of the second light guiding pipe  104  and the transflective surfaces  142  are same. In this embodiment, the sum of the inclined angles between the extension axis of the second light guiding pipe  104  and the transflective surfaces  142  is greater than 90 degrees. The beam-splitting prism  14  can be formed by adhering four triangular prisms together. The interfaces between each two adjacent triangular prisms form the transflective surfaces  142 . 
     The image sensors  16  are respectively located at the openings of the fourth light guiding pipes  108 . Each of the image sensors  16  has a sensing surface  162  facing the corresponding second mirror  112  for detecting light reflected by the corresponding second mirror  112 . The sensing surface  162  is perpendicular to the extension axis of the fourth light guiding pipe  108 . The image sensors  16  each detects the light reflected by the corresponding second mirror  112  and generates a 2D image signal. 
     The parallax processor  18  is electrically connected to the image sensors  16 . The parallax processor  18  receives and processes the image signals, thereby generating a 3D image signal. 
     Referring to  FIG. 2 , the light path in the 3D image capture apparatus  100  is described as follows. The ambient light enters into lens module  12  from the open end of the first light guiding pipe  102 . Then, the light exits from the lens module  12  and attacks on the first mirror  110 . The first mirror  110  reflects the light into the second light guiding pipe  104 , and then the light enters into the beam-splitting prism  14 . Furthermore, part of the light is reflected by the one of the transflective surfaces  142  of the beam-splitting prism  14  to one of the second mirror  112 , and another part of the light is reflected by the other transflective surface  142  to the other second mirror  112 . The two second mirrors  112  each reflects the light to the corresponding fourth light guiding pipe  108 , and finally the light transmitting in the corresponding fourth light guiding pipe  108  attacks on the sensing surface  162  of the corresponding image sensor  16 . Because the two transflective surfaces  142  are slanted to each other, the light capable of attacking on the two second mirrors  112  is from two viewing angles of the lens module  12  (equivalent to light viewed by left and right eyes). That is, the image signals received by the parallax processor  18  from the two image sensors  16  are parallax image signals. The parallax processor  18  synthesizes the two parallax images to form a 3D image. 
     In the light path from the lens module  12  to the image sensors  16 , the light is successively reflected by the first mirror  110 , the transflective surface  142  of the beam-splitting prism  14 , and the second mirror  112 . In other words, the light is reflected by three times (i.e. odd number of times). Thus, the images detected by the image sensors  16  are mirror images of the captured object. That is, the images detected by the image sensors  16  need to be mirrored before synthesized by the parallax processor  18 . 
     In this embodiment, the beam-splitting prism  14  is applied to split the light, thereby forming parallax images for a 3D image. Therefore, just one lens module  12  is used. Thus, the volume and cost of the 3D image capture apparatus  100  are reduced. 
     In an alternative embodiment, the transflective surfaces  142  of the beam-splitting prism  14  can also be perpendicular to each other. In that case, the extension axis of each third light guiding pipe  106  should be inclined to the corresponding transflective surface  142 . 
     Referring to  FIG. 3 , a 3D image capture apparatus  200  according to a second exemplary embodiment is similar as the 3D image capture apparatus  100 . The distinguishing features are that the first light guiding pipe  102  and the first mirror  110  are omitted, and the lens module  12  is located in the second light guiding pipe  104 . In the light path from the lens module  12  to the image sensors  16 , the light is reflected by two times (i.e. even times). Thus, there is no need to mirror the images detected by the image sensors  16  before synthesized by the parallax processor  18 . 
     Referring to  FIG. 4 , a 3D image capture apparatus  300  according to a second exemplary embodiment is similar as the 3D image capture apparatus  100 . The distinguishing features are that the third light guiding pipe  108  and the second mirror  112  are omitted, and the two image sensors  16  are located at the opening of the corresponding third light guiding pipes  106 . The sensing surfaces  162  are perpendicular to the extension axis of the corresponding third light guiding pipe  106 . In the light path from the lens module  12  to the image sensors  16 , the light is reflected by two times (i.e. even times). Thus, there is no need to mirror the images detected by the image sensors  16  before synthesized by the parallax processor  18 . 
     In an alternative embodiment, the first light guiding pipe  102  and the fourth light guiding pipes  108  in the first exemplary embodiment can also be both omitted. In that case, the images detected by the image sensors  16  need to be mirrored before synthesized by the parallax processor  18 . 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.