Abstract:
A folding mobile telephone having an upper terminal body and a lower terminal body is provided. The upper terminal body has an upper part with a liquid crystal display and a base, such that the upper part and the base are connected to each other via lock mechanism. This lock mechanism permits the upper part and the base to be mounted and removed in a flipping manner. The upper terminal body also has communications devices to make electrical connections. The upper terminal body has an operating mechanism that allows prescribed operations to be performed using the upper terminal body when it is connected to its base and folded against the lower terminal body (i.e., the closed state).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a mobile terminal device having an upper terminal body and a lower terminal body, which are connected via a hinge so as to allow the mobile terminal device to be opened and closed. 
     2. Description of the Related Art 
     Mobile telephones include integral mobile telephones and folding mobile telephones. In particular, folding mobile telephones are superior in portability because the mobile telephones are compact in a closed state (folded state). 
     However, liquid crystal displays provided on the folding mobile telephones are generally placed on the inner surfaces of the upper and lower terminal bodies of the folding mobile telephones in such a manner to be viewed in an opening state. Namely, in the closed state, the liquid crystal displays cannot be viewed. 
     The inability to view the liquid crystal displays when only the telephone function is used in not inconvenient. However, in the present day, various functions, such as e-mail access and Internet access, have been added to mobile telephones. When a received e-mail is read, or when various sites are viewed by accessing Internet, folding mobile telephones need to be opened every time to expose the liquid crystal displays, which is considerably troublesome. Additionally, in some cases, an e-mail message needs to be read in a crowded place. Thus, the opening operation is quite troublesome in a limited free space. 
     The above-described problem can be solved by placing the liquid crystal displays on the outer and inner surfaces of the upper and lower terminal bodies of the folding mobile telephone. However, it is quite uneconomical to have more liquid crystal displays. In addition, the thickness in the structure of the folding mobile telephone is increased, thereby contradicting a compact size, which is an advantage of folding mobile telephones. 
     Thus, in view of the above-described problem, Japanese Utility Model Registration No. 3075258 discloses a folding mobile telephone with a flipped display. Further, in Japanese Laid-Open Patent Application Heisei 10-155013 and Japanese Laid-Open Patent Application 2000-151781 (division of Japanese Laid-Open Patent Application Heisei 10-155013), the applicant of the present invention has proposed portable communication apparatuses which can change fixed forms of folding mobile telephones according to preference and use, though the publications are not devised to solve the above-described problem. 
     In the folding mobile telephone with a flipped display that is disclosed in Japanese Utility Model Registration No. 3075258, a receiver-side case having a liquid crystal display and a transmitter-side case are connected so as to be flipped by 180 degrees around a hinge, and the liquid crystal display is exposed in a closed state if necessary. 
     Moreover, in the portable communication apparatus disclosed in Japanese Laid-Open Patent Application Heisei 10-155013, one or more kinds of connectors including a bending type, a rotating type, and a straight line type are prepared for electrically and structurally connecting an upper case and a lower case, and the connectors are properly selected according to use and preference to connect the upper case and the lower case via the connectors. Besides, in the portable communication apparatus disclosed in Japanese Laid-Open Patent Application 2000-151781, cases with forms suitable for use are arbitrarily selected, and an upper case and a lower case are connected via a connector for making electrical and structural connection. 
     However, as to the folding mobile telephone with a flipped display that is disclosed in Japanese Utility Model Registration No. 3075258, although the structure of the rotating part is not discussed in detail, it is suggested that the compact size is not achieved due to a rotating part as long as the receiver-side case having the liquid crystal display is flipped by 180 degrees. In addition, it is considered that a prescribed locking mechanism is necessary for preventing the receiver-side case from rotating when a telephone function is used (the case is likely to rotate because the receiver is pressed to an ear), resulting in a more complicated mechanical structure. 
     Moreover, the portable communication apparatuses disclosed in Japanese Laid-Open Patent Application Heisei 10-155013 and Japanese Laid-Open Patent Application 2000-151781 do not present a technical idea for viewing a liquid crystal display in the closed state. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished to solve the above-described problems experienced by the related art. Thus, an aspect of the present invention is to provide a portable terminal device whereby a liquid crystal display for viewing e-mail messages, Internet sites, and other information in a closed state with a simple configuration without losing a compact design. 
     A second aspect of the present invention is to provide a portable terminal device in which electrical connection is ensured even when an upper terminal body is separated from a lower terminal body. The second aspect also allows predetermined operations to be performed from the separated upper terminal body, so that portability can be further improved when viewing e-mail messages, Internet sites, and other information. 
     To solve the above mentioned problem, a portable terminal device comprises a first case unit comprising first key buttons, a second case unit connected to the first case unit via a hinge so as to be opened and closed, a third case unit comprising a display, a connecting means for connecting the second case unit to the third case unit and a lock means for mounting and removing the third case unit from the second case unit. The connecting means electrically connects the second case unit to the third case unit to communicate each other. The lock means mounts the third case unit on the second case unit in a flipping manner. The third case unit may comprise second key buttons. The second key buttons is disposed on the same side as the display. Both the display and the second key buttons are preferably provided on an outer surface of the third case unit when the third case unit is connected to the second case unit. The lock means is a snap-in lock mechanism included in the second case nit and the third case unit. The portable terminal device is preferably a portable telephone. The lock means may be an interlocking mechanism provided in the second case unit and the third case unit. The interlocking mechanism comprises an engaged part provided in a first connecting surface of the second case unit and an engaging part which is provided in a second connecting surface of the third case unit and is removably engaged with the engaged part. The engaging part is configured such that the engaging part engaged to the engaged part is disengaged in response to a predetermined operation by an user, so that the second case unit and the third case unit are separated from each other. The portable terminal device is preferably a portable telephone. The connecting means is a pair of male and female connectors for making wired connection between the second case unit and the third case unit. The portable terminal device is preferably a portable telephone. The connecting means may be a radio part which is provided both on the second case unit and the third case unit so as to perform transmission and reception and makes wireless connection between the second case unit and the third case unit. The portable terminal device is preferably a portable telephone. 
     With the above-described configurations, the present invention has advantages discussed below. 
     According to the present invention, an upper terminal body comprises an upper part having a liquid crystal display and a base. The upper part and the base are connected to each other via lock means, which permits the upper part and the base to be mounted and removed in a flipping manner. There is provided communication means for making electrical connections, even when the upper part is connected to the base so as to expose the liquid crystal display on an outer surface in a closed state. There is also provided operating means for performing prescribed operations is provided on an outer surface of the upper part. Hence, even in the closed state, e-mail and various sites can be viewed while being freely operated. 
     Further, since the electrical connections are made by a radio system, the mobile telephone can be used in a state in which the upper part is separated from the base. E-mail messages can be read and a desired site can be viewed by accessing the Internet only by using the small and lightweight upper part while a lower terminal body is put in a bag or under the table, thereby providing a mobile telephone which is quite excellent in portability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects, features and advantages of the invention will become more fully apparent from the following detailed description taken in conjunction with accompanying drawings. In the drawings: 
         FIG. 1  is a perspective view showing a state in which a mobile telephone of the present invention is opened; 
         FIG. 2  is an exploded perspective view showing the mobile telephone; 
         FIG. 3  is a perspective view showing a state in which the mobile telephone is folded such that a liquid crystal display cannot be viewed; 
         FIG. 4  is a perspective view showing a state in which the mobile telephone is folded such that a liquid crystal display can be viewed; 
         FIG. 5  is a perspective view showing a state in which a mobile telephone of the present invention is opened; 
         FIG. 6  is an enlarged longitudinal sectional view showing a connecting part when an upper part and a base of the mobile telephone are engaged to each other; 
         FIG. 7  is an enlarged longitudinal sectional view showing a state in which the upper part and the base of the mobile telephone are separated from each other subsequently to  FIG. 6 ; and 
         FIG. 8  is a perspective view schematically showing that radio communication is performed while the upper part and the base of the mobile telephone are separated from each other. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.  FIGS. 1 to 4  describe a first embodiment of the present invention and  FIGS. 5 to 8  describe a second embodiment of the present invention. 
       FIG. 1  is a perspective view showing a state in which a mobile telephone of the present invention is opened. As shown in  FIG. 1 , in a portable terminal device, i.e., a mobile telephone of the first embodiment, an upper terminal body  11  and a lower terminal body  12  are provided. The upper terminal body  11  and the lower terminal body  12  have operating buttons for inputting telephone numbers, text, etc. on their inner surfaces. The upper terminal body  11  and the lower terminal body are connected via a hinge  13  so as to be opened and closed. The electronic circuits (not shown) required for mobile telephone functions, e-mail functions, and Internet functions are internally packaged. Hereinafter, the upper terminal body  11  serving as a major part of the present invention will be discussed in detail. 
     The upper terminal body  11  comprises an upper terminal body upper part  101  (hereinafter, simply referred to as an “upper part” in the present embodiment), an upper terminal body base  102  (hereinafter, simply referred to as a “base” in the present embodiment), a connector  103  (communication means), and lock means  104 . 
     In the upper part  101 , a liquid crystal display  105  is provided for displaying telephone numbers, addresses, text and images from e-mail messages and the Internet. A button group  106  (operating means) for realizing simple operations other than the telephone function and the operation of writing e-mail is provided under the liquid crystal display  105 . The bottom group  106  comprises a screen scrolling button and an enter button for viewing e-mail and Internet. 
     The base  102  constitutes the hinge  13  with the upper part of the lower terminal body  12  and is connected to the lower terminal body  12  so as to be opened and closed. 
       FIG. 2  is an exploded perspective view showing the mobile telephone. As shown in  FIG. 2 , the connector  103  comprises a male connector  107 , which is connected to electronic circuits packaged inside the upper part  101  and protrudes on the lower surface (connecting surface with the base) of the upper part  101 . The connector  103  further comprises a female connector  108 , which is connected via the hinge  13  to electronic circuits packaged inside the lower terminal part  12  and can be detachably fit onto the male connector  107  in the top face (connecting surface with the upper part) of the base  102 . The male connector  107  and the female connector  108  are engaged to each other to electrically connect the upper part  101  and the base  102 . 
     For the male connector  107  and the female connector  108 , contact pins are arranged in the connector so as to have normal electric connection even when the upper part  101  is flipped in such a manner as to place the liquid crystal display  105  on the back. 
     The lock means  104  is a snap-in lock mechanism provided on both sides of the upper part  101  and both sides of the base  102 . The lock means  104  comprises engaged parts  109  provided both sides of the upper part  101  and latches  110  provided on both sides of the base  102 . The lock means  104  is a hook type having a structure for lifting and disengaging the latches of the base  102 . 
     As shown in  FIG. 1 , when an ordinary telephone function is used and e-mail is written, the mobile telephone of the first embodiment is used in a state in which the upper part  101  is fit into the base  102  via the connector  103  and the snap-in lock mechanism  104  so as to position the liquid crystal display  105  such that it be viewed.  FIG. 3  is a perspective view showing a state in which the mobile telephone is folded with a liquid crystal display being placed such that it cannot be viewed. When the mobile telephone is folded in this state, as shown in  FIG. 3 , the appearance is identical to that of a conventional folding mobile telephone without exposing the liquid crystal display  105 . 
     When the user desires to read e-mail or access Internet sites, as shown in  FIG. 2 , the latches provided on both sides of the base  102  are lifted and disengaged from the engaged parts  109 . The upper part  101  is removed upward, so that the upper part  101  is separated from the base  102 . And then, the upper part  101  is flipped so as to place the liquid crystal display  105  can be viewed, and the upper part  101  is fit into the base  102  via the connector  103  and the snap-in lock mechanism  104  and is folded. This state is shown in  FIG. 4  that is a perspective view showing a state in which the mobile telephone is folded with a liquid crystal display being placed so that it can be viewed. With this configuration, the liquid crystal display  105  can be viewed from the outside, the operating button group  106  (operating means) is exposed on the outer surface of the upper part  101 , and e-mail messages and Internet sites can be viewed while the mobile telephone is in the closed state. 
     Referring to  FIGS. 5–8 , the second embodiment will be discussed below. This second embodiment is an example in which an interlocking mechanism is used as lock means and a radio system is used as communication means. 
       FIG. 5  is a perspective view showing a state in which a mobile telephone of the present invention is opened. As shown in  FIG. 5 , an upper terminal body comprises an upper part  201 , a base  202 , a radio section (communication means: not shown), and lock means  203 . 
     In the upper part  201 , a liquid crystal display  204  is provided for displaying telephone numbers, addresses, text and images from e-mail messages and the Internet. A button group  205  (operating means) for realizing simple operations other than telephone functions and writing e-mail is provided under the liquid crystal display  204 . The bottom group  205  includes a screen scrolling button and an enter button for viewing e-mail and Internet. 
     The base  202  constitutes a hinge  23  with the upper part of a lower terminal body  22  and is connected to the lower terminal body  22  so as to be opened and closed. 
     The lock means  203  is an interlocking mechanism provided on the upper part  201  and the base  202  and comprises an engaging part  206  and an engaged part  207 . 
       FIG. 6  is an enlarged longitudinal sectional view showing a connecting part when an upper part and a base of the mobile telephone are engaged to each other. As shown in  FIG. 6 , the engaging part  206  comprises an inner housing  208 , which is fixed in the lower part of an upper case  21   a  and has claws  209 , pressing parts  210  for causing the claws  209  to project and retreat. 
     The inner housing  208  is substantially formed into a convex part which is fixed in the lower part of the upper case  21   a  so as to protrude substantially as a rectangle solid from the center of the lower surface of the upper part  201  (connecting surface with the base). The claws  209  are vertically disposed so as to protrude on both side faces of a short side of a protruding part  217  from the upper part of grooves  220 . The grooves  220  are concavely disposed in a vertical direction at the center of the side faces of the short side of the protruding part  217 . The claws  209  are elastically deformed by a pressing operation of pressing parts  210 , which will be discussed later, and can be protruded and retreated from the side faces. 
     The pressing parts  210  each comprises a pressing body  211 , a snap ring  212  and a compression spring  213 . The pressing bodies  211  are substantially formed into convex parts, each having a stick-like core beam  215  extended from an operating part  214 , which is substantially formed into a rectangular solid. Grooves where the snap rings  212  are fit are each disposed at a prescribed position with a prescribed length, such that the operating parts  214  are flush with outer surfaces in a state in which the ends of the core beams  215  are in contact with the bases of the claws  209 , and the core beams  215  are inserted to connecting holes  216  so as to freely slide. The connecting holes  216  are disposed on the lower part of both sides of the inner housing  208  and connect the bases of the claws  209  and the outside. 
     The snap rings  212  are snap rings for shafts that include an E ring and a C ring, and the snap rings  212  are fit into the grooves formed around the pressing bodies  211  to prevent the pressing bodies  211  from falling. 
     The compression springs  213  are loosely fit into the bases of the core beams  215  so as to press the lower part of both sides of the inner housing  208  and the operating part  214 , and the compression springs  213  energize the operating parts  214  to the outside. 
     In the pressing parts  210 , when the operating parts  214  are pressed down, the ends of the core beams  215  press the bases of the claws  209  to elastically deform the claws  209  protruding on the sides of the protruding part, and the claws  209  are stored in the grooves  220 . When the press of the operating parts  214  is removed, the pressing bodies  211  are returned to prescribed positions by the compression springs  213  and the claws  209  simultaneously return to a state in which the claws  209  protrude on both sides, that is, their initial state. 
     The engaged part  207  has a concave part  218 , which is removably engaged to the protruding part  217  of the inner housing  208 . The lower part of the concave part  218  is substantially formed into a concave part where a step  219  is concavely disposed for engaging the claws  209 , and the engaged part  207  is fixed in the upper part of a base case  21   b.    
     In the radio part (communication means), an electric circuit (not shown) for realizing known communication protocols (e.g., infrared communication and BLUETOOTH communication) is provided so as to have two-way communication between the upper terminal body  21  and the lower terminal body  22 . Even when the upper terminal body  21  is separated from the lower terminal body  22 , it is possible to access e-mail messages, the Internet and information on the liquid crystal display  204 . 
     When an ordinary telephone function is used and e-mail messages are written, the mobile telephone of the second embodiment configured similar to the first embodiment. That is, the upper part  201  is fit into the base  202  via the interlocking mechanism  203  such that the liquid crystal display  204  is positioned such that if the folding mobile telephone is closed, the liquid crystal display would not be viewable. 
       FIG. 7  is an enlarged longitudinal sectional view showing a state in which the upper part and the base of the mobile telephone are separated from each other subsequently to  FIG. 6 . As shown in  FIG. 7 , the operating parts  214  are pressed down, so that the ends of the core beams  215  press the bases of the claws  209  to elastically deform the claws  209  protruding on the sides of the protruding part  217 , the claws  209  are stored in the grooves  211 , and the engagement is released. In this state, the upper part  201  is removed upward, so that the upper part  201  is separated from the base  202 . 
     And then, after the upper part  201  is flipped so as to place the liquid crystal display  204  on the back, the upper part  201  is pressed to the base  202 . Thus, the claws  209  are brought into contact with the inner wall of the concave part  218  and are bent so as to be stored in the grooves  211 , and the upper part  201  is pressed as it is until the claws  209  reach steps  219 . When the claws  209  reach the steps  219 , the claws  209  are engaged to the steps  219  and the upper part  201  is locked into the base  202 . In this way, the liquid crystal display  204  can be viewed from the outside and the operating button group  205  (operating means) is exposed on the outer surface of the upper part  201 . Thus, e-mail messages and Internet sites can be viewed while the mobile telephone is in the closed state. 
       FIG. 8  is a perspective view schematically showing that radio communication is performed while the upper part and the base of the mobile telephone are separated from each other. As shown in  FIG. 8 , since the mobile telephone of the second embodiment uses a radio system as communication means, the mobile telephone can be used while the upper part  201  is separated from the base  202 . E-mail messages can be read or desired Internet sites can be viewed by using the small and lightweight upper part while the lower terminal body  22  is placed a short distance away, e.g., in a bag or under the table. This provides a mobile telephone which is quite excellent in portability. 
     The above explanation discussed the detail of the mobile telephones according to the present embodiments. The present invention is not limited to the present embodiments. Wired connection may be arbitrarily made by using both of the interlocking mechanism and the connector, wireless connection may be arbitrarily made by concavely providing the snap-in locking mechanism not protruding the outer surfaces of the upper part and the base, or another lock means may be arbitrarily used. 
     Besides, although the mechanical button group provided under the liquid crystal display is discussed as an example of operating means, any form is acceptable including a mechanical button group provided on the side of the upper part and a so-called touch panel on which a switch is integrated with a liquid crystal panel. 
     Obviously, numerous additional modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.