Patent Publication Number: US-2012033353-A1

Title: Foldable electronic device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 099214926 filed in Taiwan, R.O.C. on Aug. 4, 2010, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a foldable electronic device, and more particularly to a foldable electronic device with a flexible display as a display screen. 
     2. Related Art 
     In recent years, with the rapid development of technology and information, manufacturing technologies of electronic products are also improved gradually. In consideration of the pursuit of portability and practicability, the electronic products develop towards being light, thin, short, and small. For example, screens have developed from early large-volume and large-weight cathode ray tube (CRT) displays to light-weight and thin-volume liquid crystal display (LCD) displays. Moreover, due to the pursuit of small size of electronic products for convenient carrying, the size of displays gets smaller relatively. However, common displays generally cannot have convenience in carrying and comfort in use at the same time, that is, when the screen gets smaller and can be easily carried, the area of the screen is reduced correspondingly, such that the content of the screen frame is reduced, and is inconvenient for the user for watching. In order to solve this problem, foldable electronic screens are developed, that is, a plurality of small-size displays are combined into a large-size screen, but joints are generated between the displays, and thus the frame quality is deteriorated. 
     Therefore, current flexible displays, for example, electronic paper or organic light-emitting diodes (OLED) displays, have been developed, and are available in the market. Presently, the flexible displays applied on electronic devices for the purpose of reducing the volume are in the manner of rolling. The flexible displays in the manner of rolling can overcome the disadvantage of deteriorated frame quality caused by combining a plurality of small-size displays into a large-size screen. However, the flexible display has a requirement of minimal bending curvature when being rolled up, and due to excessive small curvature, the flexible display has a fold, and cannot display normally when being unfolded again, so the flexible screen cannot be rolled up to be excessively small. Therefore, the conventional design cannot solve the problem, and the flexible display cannot be implemented on the current foldable electronic products. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is a foldable electronic device, so as to solve the problem of generation of creases when a flexible screen is applied in a foldable electronic device existing in the prior art. 
     The present invention provides a foldable electronic device, which comprises a foldable casing, a flexible electronic element, and at least one roller. The foldable casing is capable of being unfolded or folded, the flexible electronic element is disposed in the foldable casing, and the flexible screen and the foldable casing are unfolded or folded together. Furthermore, the roller is correspondingly pivoted to a bending position of the foldable casing, such that the flexible electronic element slides and is bent along the roller when being folded. 
     In the foldable electronic device of the present invention, the foldable casing has at least two casing bodies pivoted to each other and capable of being unfolded and folded with respect to each other. When the two casing bodies are unfolded with respect to each other, a bearing range is formed thereby, and the flexible electronic element is disposed on the bearing range. 
     In the foldable electronic device of the present invention, the two casing bodies are pivoted to each other through at least one pivot, the roller is pivoted to the pivot and is normally pressed against the flexible electronic element, such that the flexible electronic element slides and is bent along the roller when being folded. 
     In the foldable electronic device of the present invention, the foldable casing has three casing bodies pivoted to each other through at least two pivots and capable of unfolded and folded with respect to each other. When the three casing bodies are unfolded with respect to each other, a bearing range is formed thereby, and the flexible electronic element is disposed on the bearing range. 
     In the foldable electronic device of the present invention, the foldable electronic device comprises two rollers, and three casing bodies are pivoted to each other through at least two pivots, and two rollers are respectively pivoted to the two pivots and are normally pressed against the flexible electronic element, such that the flexible electronic element slides and is bent along the rollers. 
     In the foldable electronic device of the present invention, one of the two rollers has an outer diameter greater than that of the other one. 
     In the foldable electronic device according to the present invention, the flexible screen is capable of being unfolded or folded together with the foldable casing. However, when the flexible screen is bent, creases may be generated. Therefore, the foldable electronic device of the present invention has a roller, and the roller is disposed on a bearing to which the foldable casing is pivoted and is pressed against the flexible screen, and has a radius greater than the flexible radius of the flexible screen, such that the flexible screen is capable of being bent along the outer diameter of the roller and extending and sliding, thus no crease is generated on the flexible screen and no frictions and damages on the foldable casing occur. Therefore, the present invention solves the problems and applies the flexible display in the foldable electronic device to achieve the efficacy of having a minimal volume when being folded and having a maximal display screen when being unfolded. 
     These and other aspects of the present invention will become apparent from the following description of the preferred embodiment taken in conjunction with the following drawings, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate one or more embodiments of the invention and, together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment, and wherein: 
         FIG. 1A  is a schematic view of a foldable electronic device according to an embodiment of the present invention; 
         FIG. 1B  is a schematic structural view of a foldable electronic device according to an embodiment of the present invention; 
         FIG. 2A  is a plane cross-sectional view of the foldable electronic device in  FIG. 1 ; 
         FIG. 2B  is a schematic view of a first casing body in  FIG. 2A  folded to a second casing body; 
         FIG. 2C  is a schematic view of a third casing body in  FIG. 2B  folded to the first casing body; and 
         FIG. 3  is a schematic structural view of a foldable electronic device according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1A  is a schematic view of a foldable electronic device according to an embodiment of the present invention, and  FIG. 1B  is a schematic structural view of a foldable electronic device according to an embodiment of the present invention. Referring to  FIGS. 1A and 1B , a foldable electronic device  100  of this embodiment is a two-folded foldable electronic device, and comprises a foldable casing  110 , a flexible screen  120 , two first rollers  130 , and two second rollers  131 . The foldable casing  110  comprises a first casing body  112 , a second casing body  114 , a third casing body  116 , two first pivots  113 , and two second pivots  115 . The first pivot  113  connects the first casing body  112  and the second casing body  114 , such that the first casing body  112  and the second casing body  114  are pivoted to each other, and capable of being unfolded or folded with respect to each other. The second pivot  115  connects the second casing body  114  and the third casing body  116 , such that the second casing body  114  and the third casing body  116  are pivoted to each other, and capable of being unfolded or folded with respect to each other. Therefore, the foldable casing  110  enables the first casing body  112 , the second casing body  114 , and the third casing body  116  to be unfolded and folded with respect to each other through the arrangement of the first pivot  113  and the second pivot  115 . Furthermore, when the first casing body  112 , the second casing body  114 , and the third casing body  116  are unfolded with respect to each other to be a maximal plane, a bearing range  118  is formed thereby. Additionally, the first roller  130  is pivoted to the first pivot  113 , and is capable of rotating with respect to the first pivot  113 , and the second roller  131  is pivoted to the second pivot  115 , and is capable of rotating with respect to the second pivot  115 . The roller radius of the first roller  130  and the second roller  131  needs to be greater than the flexible radius of the flexible screen  120 , and the roller radius of the second roller  131  needs to be greater than that of the first roller  130 . 
     The flexible screen  120  of the present invention is disposed on the bearing range  118  and has a shape of rectangular plate, but is not limited thereto. The flexible screen  120  has a first edge  121 , a second edge  122  opposite to the first edge  121 , a third edge  123 , and a fourth edge  124  opposite to the third edge  123 . The first edge  121  is connected to the first casing body  112 , and the second edge  122  is connected to the third casing body  116 . The third edge  123  and the fourth edge  124  are adjacent to the first pivot  113  and the second pivot  115  simultaneously, but not connected to the first casing body  112 , the second casing body  114 , or the third casing body  116 . Therefore, only the first edge  121  and the second edge  122  of the flexible screen  120  are constrained in the foldable casing  110 , that is, the flexible screen  120  is disposed on the bearing range  118  in a floating manner. Furthermore, the flexible screen  120  further has a display surface  125 , in which the first edge  121 , the second edge  122 , the third edge  123 , and the fourth edge  124  surround the display surface  125 , and the display surface  125  is disposed with its back facing the foldable casing  110 . The display surface  125  is pressed against the first roller  130  and the second roller  131 . The flexible screen  120  is capable of being unfolded or folded together with the foldable casing  110 , the flexible screen  120  is bent and slides along an outer edge of the first roller  130  or the second roller  131  by taking the axis of the first pivot  113  or the second pivot  115  as the center of circle, and drives the first roller  130  or the second roller  131  to rotate together. 
     The folding manner of the foldable electronic device  100  is described in detail below.  FIG. 2A  is a plane cross-sectional view of the foldable electronic device in  FIG. 1 ,  FIG. 2B  is a schematic view of a first casing body of  FIG. 2A  folded to a second casing body, and  FIG. 2C  is a schematic view of a third casing body in  FIG. 2B  folded to the first casing body. The display surface  125  of the flexible screen  120  is pressed against the first roller  130  and the second roller  131 , the first edge  121  is fixed to the first casing body  112 , and the second edge  122  is fixed to the third casing body  116 . Next, the first casing body  112  performs a counter-clockwise circular motion with respect to the second casing body  114  and rotates for 180 degrees by taking the axis of the first pivot  113  as the center of circle, and then is folded to the second casing body  114 , as shown in  FIG. 2B . At this time, the first edge  121  of the flexible screen  120  is fixed to the first casing body  112 , and the flexible screen  120  is pressed against the first roller  130  of the first pivot  113 , such that the flexible screen  120  is driven by the first casing body  112  to slide and to be bent along the first roller  130 , and the first roller  130  rotates together due to the bending of the flexible screen  120 . Next, the third casing body  116  performs a clockwise circular motion with respect to the second casing body  114  and rotates for 180 degrees by taking the axis of the second pivot  115  as the center of circle, and then is folded to the first casing body  112 , as shown in  FIG. 2C . At this time, the second edge  122  of the flexible screen  120  is fixed to the third casing body  116 , and the flexible screen  120  is pressed against the second roller  131  on the second pivot  115 , such that the flexible screen  120  is driven by the third casing body  116  to slide and to be bend along the second roller  131 , and the second roller  131  rotates together due to the bending of the flexible screen  120 . 
     At this time, the foldable casing  110  is changed from an unfolded state into a folded state, and the occupied space is reduced, thus being convenient for a user to carry. In order to get an intact appearance and uniform thickness of the foldable casing  110  after being folded and get a plane without height difference of the flexible screen  120  after being unfolded, the first roller  130  and the second roller  131  must have different roller radiuses. As for the present invention, the first roller  130  has a roller radius lower than that of the second roller  131 . Furthermore, the casing body thickness of the first casing body  112 , the second casing body  114 , and the third casing body  116 , the pivot radius of the first pivot  113  and the second pivot  115 , and the roller radius of the first roller  130  and the second roller  131  need to meet the following relationships: 
       (Casing body thickness of the second casing body 114)+(Casing body thickness of the third casing body 116)&lt;(Pivot radius of the second pivot 115); 
       (Casing body thickness of the first casing body 112)&gt;(Pivot radius of the second pivot 115)−(Roller radius of the second roller 131);
 
       (Casing body thickness of the third casing body 116)&gt;(Pivot radius of the first pivot 113)−(Roller radius of the first roller 130).
 
     As the foldable casing  110  has the first roller  130  and the second roller  131  disposed therein, and the roller radius of the first roller  130  and the second roller  131  is greater than the flexible radius of the flexible screen  120 , when the flexible screen  120  is bent along the first roller  130  or the second roller  131 , no crease is generated. Furthermore, as the flexible screen  120  is pressed against the first roller  130  and the second roller  131  when being bent, such that the first roller  130  and the second roller  131  rotates together when the flexible screen  120  is bent, and no friction and damage is generated between the flexible screen  120  and the foldable casing  110 . 
       FIG. 3  is a schematic structural view of a foldable electronic device according to another embodiment of the present invention. As the structure of this embodiment is substantially the same as that of the embodiment in  FIG. 1 , only differences therebetween are described herein. A foldable electronic device  100  comprises a foldable casing  110 , a flexible screen  120 , and two first rollers  130 . The foldable casing  110  comprises a first casing body  112 , a second casing body  114 , and two first pivots  113 . The first pivot  113  connects the first casing body  112  and the second casing body  114 , such that the first casing body  112  and the second casing body  114  are pivoted to each other, and are capable of being unfolded or folded with respect to each other. Therefore, the foldable casing  110  enables the first casing body  112  and the second casing body  114  to be unfolded and folded with respect to each other through the arrangement of the first pivot  113 . Moreover, when the first casing body  112  and the second casing body  114  are unfolded with respect to each other to a maximal plane, a bearing range  118  is formed thereby. Furthermore, the first roller  130  is pivoted to the first pivot  113 , and is capable of rotating with respect to the first pivot  113 , and the roller radius of the first roller  130  needs to be greater than the flexible radius of the flexible screen  120 . The flexible screen  120  is disposed on the bearing range  118 , and has a first edge  121 , a second edge  122  opposite to the first edge  121 , a third edge  123 , and a fourth edge  124  opposite to the third edge  123 . The first edge  121  is connected to the first casing body  112 , and the second edge  122  is connected to the second casing body  114 . Furthermore, the flexible screen  120  has a display surface  125 , in which the first edge  121 , the second edge  122 , the third edge  123 , and the fourth edge  124  surrounds the display surface  125 , and the display surface  125  is disposed with its back facing the foldable casing  110 , and is pressed against the first roller  130 . The flexible screen  120  is capable of being unfolded or folded together with the foldable casing  110 , the flexible screen  120  is bent and folded along an outer edge of the first roller  130  by taking the axis of the first pivot  113  as the center of circle, and drives the first roller  130  to rotate together. 
     According to the foldable electronic device of the present invention, the flexible screen is unfolded or folded together with the foldable casing. However, when the flexible screen is folded, creases may be generated. Therefore, the foldable electronic device of the present invention has a roller, and the roller is disposed on a bearing to which the foldable casing is pivoted and is pressed against the flexible screen, and has a radius greater than the flexible radius of the flexible screen, such that the flexible screen is capable of being bent along the outer diameter of the roller and extending and sliding, and thus no crease is generated in the flexible screen and no frictions and damages on the foldable casing occur. Therefore, the present invention solves the problems and applies the flexible display in the foldable electronic device to achieve the efficacy of having a minimal volume when being folded and having a maximal display screen when being unfolded.