Abstract:
A foldable cellular phone includes a first housing, a first protruding portion, a second housing, and a second protruding portion. The first housing includes a first hinge part, the first protruding portion being disposed on the first hinge part. The second housing includes a second hinge part, the second protruding portion being disposed in the second hinge part. The first hinge part and the second hinge part couple with each other as a hinge. When the second housing rotates around the hinge relatively to the first housing, the second protruding portion corresponding to the first protruding portion is capable of acting as a stopper to stop the movement of the first protruding portion. Subsequently, the second housing is in a flip position with a predetermined maximum angle.

Description:
This application claims the benefit of Taiwan application Ser. No. 93110140, filed Apr. 12, 2004, the subject matter of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates in general to an electronic device, and more particularly to a foldable electronic device. 
   2. Description of the Related Art 
   With the rapid development in science and technology in recent years, the size of electronic device has the tendency of miniaturization. A foldable cellar phone which is handy and portable can be said to be the typical one of foldable electronic devices. 
   Referring to  FIG. 1A , an arrangement of a stopper in a conventional foldable electronic device is shown. A foldable electronic device  100  includes a main body  102 , a flip cover  104  and a rotation device  106 . The flip cover  104  and main body  102  are pivotally connected together via the rotation device  106 . That is, the flip cover  104  can rotate against the main body  102  by means of the rotation device  106 . The maximum flip angle that the flip cover  104  can rotate against the main body  102  is determined according to how the pair of stoppers  108   a  and  108   b , disposed on one side of the main body  102 , protrude from the main body  102 . 
   Please refer to both  FIG. 1B  and  FIG. 1C .  FIG. 1B  is a diagram showing the status when the stopper  108   b  of a conventional foldable electronic device protrudes from the main body, while  FIG. 1C  is a diagram showing another status when the stopper  110  of a conventional foldable electronic device protrudes from the main body. 
   The flip cover  104  rotates and flips against the main body  102  via the rotation device  106 . When the stopper  108   b  or the stopper  110  stops the movement of the flip cover  104 , the flip cover  104  will stop at a maximum flip angle. 
   As shown in  FIG. 1B  and  FIG. 1C , the difference between the stopper  108   b  and the stopper  110  lies in the external design of protruding from the main body  102 , so the maximum flip angle that the flip cover  104  could flip will differ accordingly. 
   Since the stopper  110  is different in external design, the maximum flip angle θ 1  of the flip cover  104  as shown in  FIG. 1B  will be larger than the maximum flip angle θ 2  of the flip cover  104  as shown in  FIG. 1C . 
   Referring to  FIG. 2 , another arrangement of the stopper of the conventional foldable electronic device is shown. Foldable cellar phone  200  includes a main body  202 , a flip cover  204  and a rotation device  206 . The flip cover  204  and main body  202  are coupled together via the rotation device  206 . 
   A pair of stopper  208   a  and  208   b  of the foldable electronic device  200  are disposed on one side of the flip cover  204 , and are different from the position on which stopper  108   a  and  108   b  of the foldable electronic device  100  of  FIG. 1A  are disposed on the main body  102 . 
   When the flip cover  204  rotates and flips against the main body  202 , the stoppers  208   a ,  208   b  disposed on one side of the flip cover  204  can stop the movement of the flip cover  204 , so the flip cover  204  can be positioned at a predetermined maximum flip angle. The magnitude of the maximum flip angle is determined according to how the pair of stoppers  208   a  and  208   b  protrude from the flip cover  204 . 
   In the above-mentioned conventional foldable electronic devices, the maximum flip angle of the flip cover is determined by where the stopper is arranged, i.e., disposed on the main body or the flip cover. 
   Consequently, the maximum flip angle that the flip cover rotates against the main body will be restricted by the external design of the stopper. Moreover, after a long term operation, collision between the flip cover and the main body makes the flip cover or the main body peels its coating off easily, noise is also generated. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the invention to provide a foldable electronic device. The flip angle of the foldable electronic device of the invention not restricted by the external arrangement of the stopper of the foldable electronic device when the flip cover rotates and flips against the main body. Moreover, the flip cover or the main body of the foldable electronic device will not easily peel off its coating when the flip cover flips against the main body. There will be free of noise even when collision occurs between the flip cover and the main body. 
   The invention achieves the above-identified object by providing a foldable electronic device having a first housing, a first protruding portion, a second housing, a second protruding portion and a pivotal connection. The first housing has a first hinge part on which a first protruding portion is disposed. The second housing has a second hinge part, and the second housing can rotate against the first housing via the pivotal connection between the second hinge part and the first hinge part. The second protruding portion is disposed on the second hinge part and corresponds to the first protruding portion of the first hinge part. When the second housing rotates against the first housing, the first protruding portion of the first hinge part stops the movement of the second protruding portion of the two hinge parts for the second housing to be positioned at a flip angle. 
   In the foldable electronic device of the above invention, the first protruding portion, the first hinge part and the first housing can be a formed-in-one-block structure. While the second protruding portion, the second hinge part and the second housing can be a formed-in-one-block structure as well. 
   Besides, in the foldable electronic device of the above invention, the first hinge part can have a shaft on which the first protruding portion is disposed, while the second hinge part can have an axle hole on which the second protruding portion is disposed. The second hinge part and the first hinge part are pivotally connected via the matching of the axle hole and the shaft, and the second housing can rotate against the first housing around the shaft. 
   Moreover, in the foldable electronic device of the above invention, the flip angle is determined according to the position of the first protruding portion as disposed on the shaft, and the position of the second protruding portion as disposed inside the axle hole. On the other hand, a third protruding portion can be disposed inside the axle hole, the axle hole and shaft can be closely jointed via the third protruding portion for the second housing to rotate against the first housing. 
   According to another object of the invention, a pivotal joint including a first hinge part, a first protruding portion, a second hinge part and a second protruding portion is provided. The first hinge part has a shaft on which a first protruding portion is disposed. The second hinge part has an axle hole on which a second protruding portion is disposed. Via the pivotal connection between the axle hole and the above shaft, the second hinge part can rotate against the hinge part. When the second hinge part rotates against the hinge part to a maximum predetermined angle, the first protruding portion on the shaft can stop the second protruding portion inside the axle hole. Therefore, the first hinge part and the second hinge part are relatively stopped and positioned. 
   Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a diagram of the stopper arrangement of a conventional foldable electronic device; 
       FIG. 1B  is a diagram showing the rotation of the flip cover is ultimately stopped by the stopper located on the main body of a conventional foldable electronic device; 
       FIG. 1C  is a diagram showing a smaller maximum opening angle of the flip cover due to different external design of the stopper; 
       FIG. 2  is another diagram of the stopper disposed in the flip cover of a conventional foldable electronic device; 
       FIG. 3A  is a decomposition diagram of the pivotal joint of the foldable electronic device according to a preferred embodiment of the invention; 
       FIG. 3B  is the decomposition diagram of the pivotal joint in another angle according to a preferred embodiment of the invention; 
       FIG. 4  is a partial diagram of the main body of the foldable electronic device according to a preferred embodiment of the invention; 
       FIG. 5  is a partial diagram of the flip cover of the foldable electronic device according to a preferred embodiment of the invention; 
       FIG. 6  is a partial cross-sectional view of the foldable electronic device according to a preferred embodiment of the invention; and 
       FIG. 7  is a partial cross-sectional view of another foldable electronic device according to a preferred embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG. 3A , a decomposition diagram of the pivotal joint of the foldable electronic device according to a preferred embodiment of the invention is shown. The foldable electronic device  300  includes a first housing, a pivotal joint  301  and a second housing. For the purpose of illustration, the first housing in the present preferred embodiment can be, for example, a main body  302 , while the second housing can, for example, be a flip cover  304 . However, the scope of protection is not limited thereto. Moreover, the foldable electronic device  300  of the present preferred embodiment can be a communication device such as a notebook computer or a personal digital assistant (PDA). 
   The pivotal joint  301  includes a first hinge part  306  and a second hinge part  312 . The first hinge part  306  is disposed on the main body  302 , while the second hinge part  312  is disposed on the flip cover  304 . The first protruding portion  310  is disposed on the first hinge part  306  of the main body  302 . The second protruding portion  316  is disposed on the second hinge part  312  of the flip cover  304 , while the second protruding portion  316  corresponds to the first protruding portion  310  of the first hinge part  306 . 
   Via the pivotal joint  301  formed by the first hinge part  306  and the second hinge part  312 , the flip cover  304  can rotate against the main body  302 . When the flip cover  304  rotates against the main body  302 , the first protruding portion  310  of the first hinge part  306  can stop the movement of the second protruding portion  316  of the second hinge part  312  and thus stop the flip cover  304  at a maximum flip angle a (not shown in the diagram). That is, the second protruding portion  316  has the same effect as the stopper and positioning device. 
   Referring to  FIG. 3B , the pivotal joint in another angle of the foldable electronic device according to a preferred embodiment of the invention is shown. In practice, as shown in  FIG. 3B , the first hinge part  306  and the second hinge part  312  are respectively disposed and pivotally jointed to make the flip cover  304  rotate against the main body  302 . 
   To clearly understand the pivotal connection between the main body  302  and the flip cover  304  as well as the position after the flip cover  304  rotates against the main body  302 , please refer to  FIG. 4  and  FIG. 5 .  FIG. 4  is a partial diagram of the main body of the foldable electronic device according to a preferred embodiment of the invention, while  FIG. 5  is a partial diagram of the flip cover of the foldable electronic device according to a preferred embodiment of the invention. 
   In  FIG. 4 , the shaft  308  with steps is disposed inside the first hinge part  306  of the main body  302 , while the first protruding portion  310  is disposed on the shaft  308 . In a preferred practice, the first protruding portion  310  can be a cylinder. 
   In  FIG. 5 , the second hinge part  312  of the flip cover  304  has an axle hole  314  corresponding to the shaft  308  of  FIG. 4 . The diameter of the axle hole  314  is slightly larger than the outer diameter of the shaft  308 , so the first hinge part  306  can be cupped into the axle hole  314  of the second hinge part  312  via the shaft  308  to form a pivotal joint  301  by the first hinge part  306  and the second hinge part  312 . Via the pivotal connection between the axle hole  314  and the shaft  308 , the first hinge part  306  can rotate against the second hinge part  312  to make the flip cover  304  rotate against the main body  302 . 
   Besides, the second protruding portion  316  is disposed inside the axle hole  314 . The second protruding portion  316  serves as a stopper to stop the first protruding portion  310 . That is, when the second hinge part  312  rotates against the first hinge part  306  to a maximum predetermined angle, the first protruding portion  310  is stopped rotating by the second protruding portion  316 . That is, the flip cover  304  will stop rotation and will be positioned to a maximum flip angle a relative to the main body  302  (as shown in  FIG. 6 ). 
   Moreover, the maximum predetermined angle that the second hinge part  312  rotates against the first hinge part  306  is determined according to the relative position between the first protruding portion  310  disposed on the shaft  308  and the second protruding portion  316  disposed inside the axle hole  314 . For example, if the first protruding portion  310  is disposed on the shaft  308  with an increase of 5 degrees of angular displacement away from the second protruding portion  316 , while the position of the second protruding portion  316  as disposed inside the axle hole  314  remains unchanged, the second hinge part  312  can rotate 5 more degrees against the first hinge part  306 . Consequently, the maximum flip angle a that the flip cover  304  can rotate against the main body  302  can increase an angular displacement of 5 degrees. 
   Relatively, if the second protruding portion  316  is disposed on the lateral side of the axle hole  314  with an increase of 5 degrees of angular displacement away from the first protruding portion  310 , while the position of the first protruding portion  310  as disposed on the shaft  308  remains unchanged, the maximum flip angle a between the main body  302  and the flip cover  304  will increase by 5 degrees. Therefore, the positioning mechanism of the invention can precisely control the required angle for the flip cover  304  to be flipped and positioned. 
   Referring to  FIG. 6 , a partial cross-sectional view of the foldable electronic device according to a preferred embodiment of the invention is shown. When rotating against the main body  302 , the flip cover  304  will be relatively positioned to a maximum flip angle a by the main body  302  because the movement of the second protruding portion  316  disposed on the flip cover  304  is stopped by the first protruding portion  310  disposed inside the main body  302 . 
   Referring to  FIG. 7 , a partial cross-sectional view of a foldable electronic device according to another preferred embodiment of the invention is shown. The foldable electronic device  700  according to the present preferred embodiment differs from the prior preferred embodiment in that a first protruding portion  702  and a second protruding portion  704  are disposed on different positions. Moreover, the foldable electronic device  700  according to the present preferred embodiment further includes a third protruding portion  706 . The third protruding portion  706  is disposed on a lateral wall of the axle hole  314 . With the additional third protruding portion  706 , the axle hole  314  can be even closely cupped with the shaft  308  for the second hinge part  312  to rotate against the first hinge part  306  even firmly. In other words, the flip cover  304  can rotate against the main body  302  even firmly. 
   The change the disposition of the first protruding portion  702  or the second protruding portion  704  will adjust the maximum flip angle. The maximum flip angle β, as shown in  FIG. 7 , is larger than the maximum flip angle a as shown in  FIG. 6 . 
   In order to reduce the cost of mold production, the first protruding portion  310 , the shaft  308 , the first hinge part  306  and the main body  302  can be formed in one block. Since the external design and position of the first protruding portion  310  could be formed by the mold before mold injection, no extra cost will be required for the first protruding portion  310  to be embedded into the shaft  308 . Similarly, the second protruding portion  316 , the second hinge part  312  and the flip cover  304  can be manufactured using a formed-in-one-block structure. 
   The foldable electronic device of the invention uses the first protruding portion and the second protruding portion respectively disposed inside the main body and the flip cover to serve as stoppers when the flip cover rotates and flips against the main body. The maximum flip angle of the foldable electronic device can be therefore precisely controlled and is not restricted by the external design of the main body and the flip cover. On the other hand, the foldable electronic device of the invention can solve the collision problem between the foldable electronic device flip cover and main body, preventing the flip cover and the main body from peeling or cracking due to collision, which usually occurs in the conventional foldable electronic device. Moreover, the first protruding portion and the second protruding portion respectively disposed inside the flip cover and the main body can effectively reduce the noise caused by the fraction therebetween, because the flip cover is stopped and positioned inside the foldable electronic device and the noise generated can be effectively contained within. 
   While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.