Abstract:
A 3D display device includes two display portions ( 200, 201 ) each having a display for generating a particular image thereon. The two display portions are substantially symmetrically arranged. Images associated with the two display portions are slightly different from each other. An electronic device includes a main body ( 10 ) and an above-described display device ( 20 ). The display device is rotatably connected to the main body. The 3D display device and the electronic device with the 3D display device can provide 3D images directly and also provide 2D images to with a person via a naked eye. In addition, the 3D display device and the electronic device are very simple in construction and easily manufactured.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to display devices and, more particularly, to a 3D (three-dimensional) display device and an electronic device with the display. 
   2. Discussion of the Related Art 
   With the rapid development of communication technology, mobile phones have become a commonplace communication tool in the life of people, as a whole. Nowadays, more and more mobile phones have color displays and deliver multimedia messages. As a result, high-quality imaging systems, which can clearly and realistically display images and/or messages, should, advantageously, be provided. A system which can display 3D images has the potential to be popular with consumers since most present-day displays are limited to 2D (two-dimensional). 
   A person&#39;s two eyes can see objects respectively. Because there is a distance between the two eyes, images of an object that are perceived in the two eyes are slightly different. This difference in the perceived images is called parallax. The brain of a person combines the two different images, thereby generating a composite 3D image. That is, the person sees a 3D object. 
   In conjunction with the above theory, 3D shutter glasses have been produced and made available. A controller controls signals, which are sent to a display of a computer or a mobile phone. Left eye signals and right eye signals are sent alternately so that the display generates left eye images and right eye images accordingly. Correspondingly, shutters of the 3D shutter glasses are controlled to selectively cover the left eye and right eye, respectively. Thereby, the left eye sees the left images and the right eye sees the right images, alternately. People can see/perceive 3D images for persistence of vision. There are some shortcomings with such a shutter system. Firstly, it is inconvenient to wear the 3D shutter glasses. Secondly, people without 3D shutter glasses would tend to see ghost images on the display, which would appear abnormal. 
   What is needed, therefore, is a display device, which can provide 3D images and 2D images directly to people with the naked eye. 
   SUMMARY OF THE INVENTION 
   A 3D display device includes two display portions each capable of generating an image. The two display portions are symmetrically arranged. Images displayed by each of the two display portions are slightly different. 
   An electronic device includes a main body and a display device. The display device includes two display portions, each configured for generating a separately controllable image. The two display portions are symmetrically arranged, and the display device, as a whole, is rotatably connected to the main body. Images displayed by each of the two display portions are slightly different. 
   The 3D display device and the electronic device with the 3D display device can provide 3D images directly and also provide 2D images to people with the naked eye. Therefore, it is very convenient. In addition, the 3D display device and the electronic device are very simple and are easily manufactured. 
   Other advantages and novel features of preferred embodiments of the present 3D display device will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Many aspects of the electronic device with a 3D display can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, the emphasis instead being placed upon clearly illustrating the principles of the electronic device with a 3D display. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
       FIG. 1  is an exploded, isometric view of an electronic device with a 3D display, in accordance with a preferred embodiment; 
       FIG. 2  is an assembled, isometric view of the electronic device with a 3D display of  FIG. 1 , showing one state; 
       FIG. 3  is similar to  FIG. 2 , but shows another state with the display portion rotated 90° relative to the state seen in  FIG. 2 ; and 
       FIG. 4  is a top view imaging schematic, employing the 3D display of  FIG. 2 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   A 3D display is shown and detailed as follows for the purposes of providing a simple description of the preferred embodiment. The present 3D display and embodiments thereof are not to be construed as being limited to the following description. Referring to  FIG. 1 , a mobile phone  3  includes a main body  10  and a display device  20 . 
   The main body  10  includes a keypad portion  100 , a base portion  102 , a connecting portion  104 , an extending portion  106 , and a nut  108 . With a plurality of keys (not labeled) thereon, the keypad portion  100  is approximately cuboid-shaped (i.e., approximately a rectangular parallelepiped). The base portion  102  is formed at one end of the keypad portion  100  for supporting the mobile phone  3 . The connecting portion  104  is formed at another end of the keypad portion  100 , opposite to the base portion  102 . The extending portion  106  is approximately cuboid-shaped. The extending portion  106  is connected to the keypad portion  100  by the connecting portion  104 . The connecting portion  104  and the extending portion  106  together can be considered to constitute a connective unit  105 , allowing the display device  20  to be mounted relative to the keypad portion  100 /main body  10 . The keypad portion  100  is upward sloping, and the extending portion  106  is vertical relative to the base portion  102 . A through hole  107  is defined substantially centrally in the extending portion  106 . The through hole  107  has two sections with different diameters, and a step  109  is formed at the joint of the two sections. The nut  108  defines a “+” shaped slot (not labeled) in one face thereof and a hole (not shown) in the center of the opposing face. The “+” shaped slot is configured for receiving a Phillips screw driver head and/or a flat screw driver head. Alternately, the slot could be shaped solely for receiving a flat screw driver head. The nut  108  has a screw thread in the hole. 
   The display device  20  includes a first display portion  200 , a second display portion  201 , and a middle portion  202 . The middle portion  202  is a rectangle-shaped board. A columnar pole or post  203  is formed on the middle portion  202  in the center thereof. The outside wall of the pole  203  has a screw thread  205  on an end thereof opposite the middle portion  202 . The pole  203  is inserted into the nut  108  and engages with the nut  108  by the mating screw threads. Each of the first display portion  200  and the second display portion  201  has a display and a microlens array (not shown). The first and second display portions  200 ,  201  are connected to two opposite ends/sides of the middle portion  202  by a first hinge  204  and a second hinge  206 , respectively. The first and second display portions  200 ,  201  are separately rotatable relative to the middle portion  202 , and can rest at any position, within angular limits of hinges  204 ,  206 , respectively. The microlens arrays are used to focus incidence lights of the displays of the first and second display portion  200 ,  201  in order that lights which should enter the left eye do not enter the right eye and lights which should enter the right eye do not enter the left eye. 
   In assembly, the pole  203  of the display device  20  is inserted into the through hole  107  of the main body  10 , and the display device  20  is assembled onto the main body  10 . Then, the nut  108  is screwed on the pole  203  of the display device  20 . The step  109  of the main body  10  stops the nut  108  from protruding further into the main body  10  from a side thereof, next to the display device  20 . Thereby, the display device  20  is connected to the main body  10 , and the display device  20  is rotatably connected relative to the main body  10  along an axis of the pole  203 . 
   Referring to  FIG. 2 , the first and second display portions  200 ,  201  are positioned substantially symmetrically at two sides of the middle portion  202 , and an obtuse angle (advantageously 140°˜175°) exists between the middle portion  202  and both the first and second display portions  200 ,  201 . Accordingly, the first and second display portions  200 ,  201  are also at an obtuse angle relative to one another, beneficially 130°˜170°. The main body  10  is centrally below the first and second display portions  200 ,  201  (i.e., directly below the middle portion  202 ). In this state, a person&#39;s two eyes correspond to the first and second display portions  200 ,  201 , respectively. Therefore, the left eye tends to see images of the second display portion  201  predominantly, if not only, and the right eye tends to see images of the first display portion  200  predominantly, if not only, when a distance between the eyes and the respective displays is appropriate. Specifically, there is an angular preference for one eye to see one of portions  200 ,  201  significantly better than the other. For example, when the display portions  200 ,  201  are obtusely angled in the manner shown, one&#39;s right eye will be able to see the left or first display portion  200  much more directly and thus more clearly than the second display portion  201 . The images generated on the first and second display portion  200 ,  201  are slightly different with respect to each other. The images displayed by each are individually controlled by a controller (not shown) in the mobile phone  3 . As such, the left and right eyes see different images, respectively. Thus, a person will see 3D images by management in his or her brain. 
   Referring to  FIG. 3 , when the display device  20  rotates 90° relative to the main body  10  and the first display portion  200  accordingly rotates to a position above the middle portion  202 , the second display portion  201  becomes hidden behind the main body  10 . The angle between the first display portion  200  and the back (not labeled) of the middle portion  202  is 180°. The mobile phone  3  shown in  FIG. 3  is rotated counter-clockwise an angle of 90°. In this state, people can see 2D images on the display of the first display portion  200  as usual. 
   Referring to  FIG. 4 , an angle between the middle portion  202  and each of the first and second display portions  200 ,  201  is “α”, a distance of centers of the first and second display portions  200 ,  201  is “H”, and a distance between the centers of two corresponding eyes is “S”. An appropriate distance between the eyes and the displays is “D” when the left eye sees images of the second display portion  201  only and the right eye sees images of the first display portion  200  only. It can be inferred that:
 
β=180°−α,  (1);
 
 L=H /(2 tg β)+ S /(2 tg β),  (2);
 
 L=H /(2 tg (180°−α))+ S /(2 tg (180°−α)),  (3); and
 
 D=L+d=H /(2 tg (180°−α))+ S /(2 tg (180°−α))+ d.   (4).
 
“H”, “S”, “α” and “d” are determined by the structure of the display device  20 . Therefore, if only a distance between the eyes and displays “L” satisfies the formula (4), people can see 3D images. Accordingly, if people want to see 3D images at a different distance “D”, they can change the angle “α” to accomplish such viewing.
 
   In an alternative embodiment, the first and second display portions  200 ,  201  and the middle portion  202  could be integrated into one, allowing the first and second hinges to be omitted. The base portion  102  could also be omitted. 
   It is believed that the 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 invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.