Abstract:
To provide a superposition type portable terminal unit in which functions other than opening and closing functions are added to opening and closing operations thereby to improve the operating performance of the portable terminal unit. In a superposition type portable terminal unit in which a first housing having at least a display section and a second housing having at least an operation section, in a close state where the display section and the operation section face in the same direction and the housings are superimposed on each other so that the operation section of the second housing is covered with the first housing, are coupled at their ends by a coupling part having an axis in a direction where the both housings are pierced, the unit is put in an open state in case that the first housing is turned about the axis from the close state in any of a clockwise direction and a counterclockwise direction; and a control unit is provided, which selects a screen so that a first screen is displayed in the display section in case that the first housing is turned in relation to the second housing clockwise from the close state, and so that a second screen is displayed in the display section in case that the first housing is turned in relation to the second housing counterclockwise.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority from and incorporates herein by reference the commonly-assigned Japanese Patent Application No. 2003-012405, filed on Jan. 21, 2003. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a portable terminal unit such as a mobile telephone or a PDA (Personal Digital Assistant), and specifically to a portable terminal unit configured to have a plurality of housings which are coupled to enable them to be overlapping each other. 
   2. Description of the Related Art 
   Conventionally, a folding type mobile telephone  2  shown in  FIG. 17  is generally known as a folding type portable telephone including two housings which can be folded. In the folding type mobile telephone  2 , a display screen  12  such as LCD (Liquid Crystal Display) which displays output information and a speaker  13  which are provided on an inner face  10  of one housing  4 , and an operation section  16  and a microphone  15  are provided on an inner face  14  of another housing  6 . 
   The operation section  16  has a cursor key  18  which for indicating upward, downward, right and left directions so that items displayed on the display screen  12  can be selected, and ten keys  20  for inputting numerals, characters, etc., and other keys for various functions operation section. 
   In such the folding type mobile telephone  2 , a menu selecting screen  22  as shown in  FIG. 18  is displayed on the display screen  12  so that a user can select any of its various functions which he or she wants to use. 
   However, the folding type mobile telephone  2  as shown in  FIG. 17  has a problem that while the housing  4  and the housing  6  are folded to be close to each other, the image displayed on the display screen  12  cannot be seen unless the housings  4  and  6  are opened so as to come apart from each other, and the information cannot be browsed in a folded-up state even though information is displayed on the display screen  12 . 
   In order to solve such a problem that it is troublesome and annoying to open the housings  4  and  6  of the folding type mobile telephone  2  in order to browse the display screen  12 , there have been proposed some mobile phone sets in which the display screen  12  is directed outward not only in an opened state but also in a folded state or a state corresponding to the folded state. 
   Examples of the portable terminal unit are the overlapping type portable terminal units disclosed in JP-A-H11-215218, JP-A-2002-141984 and JP-A-2002-135380. These overlapping type portable terminal units are so designed that the display screen provided on one of the housings is directed outward when the two housings that are coupled are opened, which is substantially same manner as the folding type mobile telephone  2  shown in  FIG. 17 . 
   However, the design of these overlapping type portable terminal units as disclosed in JP-A-H11-215218, JP-A-2002-141984 and JP-A-2002-135380 are different from the folding type mobile telephone  2  such that one of the housings can be folded and overlapped on another housing by twisting it 180 degree at a coupling section between two housings. Therefore, it is possible to overlap the two housings each other with the display face directing outward. 
   Disclosed in JP-A-H07-288860 is another type of the conventional overlapping type portable terminal unit. The conventional overlapping type portable terminal unit is so designed that one housing provided with a display screen and another housing provided with an operation section are coupled each other at their end portions, in a state which the display screen and the operation section are directed in the same direction, through a shaft which is provided in a direction of passing through these housings. 
   This overlapping type portable terminal unit can be opened, by rotating one housing with respect to another housing around the shaft at an angle of 180 degree. Further, the two housings can be kept overlapped each other with the display screen directed outward. Thus, even if a user does not open the two housings, he or she can see an image displayed on the display screen. 
   In the conventional overlapping type portable terminal units, the display screen can be seen without opening the two housings. However, in the case that a user needs to operate with the operation section, after all, he or she have to rotate one of the two housings at an angle of 180 degree to change the portable terminal unit from the closed state to the opened state. 
   Operations to change from the closed state to the opened state are somewhat different according to the kind of overlapping type portable terminal unit. However, these operations are simple, and complex operations are not required. Therefore, although the operation for making the opened state from the closed state is always performed in order to make the opened state, addition of any other functions to this opening operation itself is not taken into consideration at all. Therefore, there is a problem that operability of the overlapping type portable terminal unit cannot be improved in this point. 
   To the contrary, also in the case that the overlapping type portable terminal unit is changed from the opened state to the closed state, addition of any other functions to this closing operation itself is not taken into consideration at all. Therefore, there is a problem that operability of the overlapping type portable terminal unit cannot be improved also in this point. 
   SUMMARY OF THE INVENTION 
   The object of the invention is to provide a portable terminal unit in which functions other than the opening and closing functions are added to the opening and closing operations to improve the operability of the portable terminal unit. 
   The invention provides a portable terminal unit having: a first housing and a second housing to be provided in a state that said first housing and said second housing overlap each other. A coupling section couples said first housing and second housing to each other at their end portions so that said first and second housings can be relatively rotated around a shaft that passes through said first and second housings. An operation section is provided on a surface of said second housing, which faces said first housing. A display section is provided on a surface of a first side of said first housing, which is opposite to a second side facing said second housing. A control section controls said display section. The portable terminal unit is in a closed state when said first housing and said second housing are overlapped and the portable terminal units is in an opened state and said operation section is exposed outside by clockwise or counterclockwise rotation of said first housing from the closed state. The control section controls to display a first screen on said display section when said first housing is rotated in relation to said second housing clockwise from the closed state, and controls to display a second screen on said display section when said first housing is rotated in relation to said second housing counterclockwise from the closed state. 
   The invention also provides a portable terminal unit having: a first housing and a second housing to be provided in a state that said first housing and said second housing overlap each other. A coupling section couples said first housing and second housing to each other at their end portions so that said first and second housings can be relatively rotated around a shaft that passes through said first and second housings. An operation section is provided on a surface of said second housing, which faces said first housing. A display section is provided on a surface of a first side of said first housing. A control section controls said display section. A storing section stores data of a plurality of applications. The portable terminal unit is in a closed state when said first housing and said second housing are overlapped and the portable unit is in an opened state when said operation section is exposed outside by clockwise or counterclockwise rotation of said first housing from the closed state. The control section starts a first application by reading data of the first application from said storing section and controls to display the first screen corresponding to the first application on said display section when said first housing is rotated in relation to said second housing clockwise from the closed state. The control section starts a second application by reading data of the second application from said storing section and controls to display the second screen corresponding to the second application on said display section when said first housing is rotated in relation to said second housing counterclockwise from the closed state. 
   The first screen is displayed on the display section when the first housing is rotated in relation to the second housing clockwise, and the second screen different from the first screen may be displayed on the display section when the first housing is rotated in relation to the second housing counterclockwise. Therefore, various functions can be added to the opening and closing operations. As a result, the operability of the portable terminal units can be improved. 
   Further, since the operations by opening and closing the first housing and second housing are entirely different from the operations by a ten key and a cursor key, a user can perform the opening and closing operations in clear distinction from the operations by the ten key and the cursor key. Therefore, the operability of the portable terminal unit is improved. 
   Further features and advantages will appear more clearly on a reading of the detailed description, which is given below by way of example only and with reference to the accompanying drawings wherein corresponding reference characters on different drawings indicate corresponding parts. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view showing in a closed state an overlapping type mobile telephone  30  according to one embodiment of the invention. 
       FIG. 2  is a left side view of the overlapping type mobile telephone  30  in  FIG. 1 . 
       FIG. 3  is a front view showing in an open state the overlapping type mobile telephone  30  in  FIG. 1 . 
       FIG. 4  is a rear view of the overlapping type mobile telephone  30  in  FIG. 3 . 
       FIG. 5  is a partially enlarged view showing a three way lever key  44  of the overlapping type mobile telephone  30  in  FIG. 1 . 
       FIG. 6  is a block diagram showing a circuit of the overlapping type mobile telephone  30  according to one embodiment of the invention. 
       FIG. 7  is a diagram showing a rotating state of a first housing  32  of the overlapping type mobile telephone  30  in relation to a second housing  34  and their positions. 
       FIG. 8  is a diagram showing, in a first embodiment, a standby mode screen  80  displayed on a display screen  12  in the closed state, and an address book screen  82  and a menu selecting screen  84  which are displayed in the opened state. 
       FIG. 9  is a diagram showing, in a second embodiment, a standby mode screen  86  displayed on the display screen  12  in the closed state, and an address book screen  82  and an E-mail menu screen  90  which are displayed in the opened state. 
       FIG. 10  is a diagram showing, in a third embodiment, an address book screen  92  displayed on the display screen  12  in the closed state, and a screen during call-making  94  and a mail creating screen  96  which are displayed in the opened state. 
       FIG. 11  is a diagram showing, in a fourth embodiment, the address book screen  92  displayed on the display screen  12  in the closed state, and the screen during call-making  94  and a received mail box screen  102  which are displayed in the opened state. 
       FIG. 12  is a diagram showing, in a fifth embodiment, a received mail box screen  104  displayed on the display screen  12  in the closed state, and a screen during call-making  106  and a mail creating screen  108  which are displayed in the opened state. 
       FIG. 13  is a diagram showing, in a sixth embodiment, a received mail box screen  110  displayed on the display screen  12  in the closed state, and the screen during call-making  106  and a media player screen  114  which are displayed in the opened state. 
       FIG. 14  is a diagram showing, in a seventh embodiment, an incoming-call history screen  116  displayed on the display screen  12  in the closed state, and the screen during call-making  106  and the mail creating screen  108  which are displayed in the opened state. 
       FIG. 15  is a diagram showing, in an eighth embodiment, an image reproduction screen  122  displayed on the display screen  12  in the closed state, and an image editing screen  124  and a mail creating screen  126  which are displayed in the opened state. 
       FIG. 16  is a diagram showing, in a ninth embodiment, a mail creating screen  128  displayed on the display screen  12  in the opened state, and a camera screen  130  and a GPS screen  132  which are displayed in the closed state. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   An Embodiment of a portable terminal unit according to the invention will be specifically described with reference to drawings. 
     FIGS. 1 to 16  are drawings to be referred for explaining an overlapping type mobile telephone  30  (corresponding to the portable terminal unit) according to an embodiment of the invention. A mobile telephone  30  as shown in these figures will be described with the same reference numerals for the substantially same sections in the conventional folding type portable telephone  2 , and duplicate description of the substantially same structure will be omitted. 
   As shown in  FIGS. 1 and 2 , this overlapping type mobile telephone  30  includes a first housing  32  and a second housing  34  which are coupled at their end portions by a coupling section  36  having a shaft passing through the housings  32  and  34 . 
   In the overlapping type mobile telephone  30 , a display section  11  is provided on a surface of the first housing  32 , which is on opposite side to the second housing  34 , so that a display screen  12  can be seen from outside even when the first housing  32  and the second housing  34  are overlapped. 
   A main operation section  17  corresponding to the operation section  16  of the conventional folding type mobile telephone  2  is provided in the second housing  34 . Further, a side key  42  and a three way lever key  44  as auxiliary operation sections are provided on the respective side surfaces  38  and  40  of the first housing  32  and the second housing  34  in order to enable to operate even in a state that the first housing  32  and the second housing  34  are closed. 
   Further, on the surface of the first housing  32  where the display section  11  is provided, a speaker  13  is provided at an end opposite to the coupling section  36 . On the surface of the second housing  34  where the main operation section  17  is provided, a microphone  15  is provided at an end on the opposite side to the coupling section  36 . 
   In the overlapping type mobile telephone  30 , when the first housing  32  is rotated clockwise (the direction of an arrow “a” in  FIG. 2 ) around the shaft of the coupling section  36  through an angle of 180 degrees from the state that the first housing  32  and the second housing  34  are overlapped, the overlapping type mobile telephone  30  is put in an opened state. In the opened state the main operation section  17  provided in the second housing  34  is seen on the outside as shown in  FIG. 3 . 
   Further, also by rotating the first housing  32  counterclockwise (direction of an arrow b) through an angle of 180 degrees, as shown in  FIG. 1 , the overlapping type mobile telephone  30  can be put in the opened state. In the opened state the main operation section  17  provided in the second housing  34  is seen on the outside as shown in  FIG. 3 . 
   When rotated in the clockwise direction or the counterclockwise direction, the display screen  12  rotates so that it faces in substantially same direction as the main operation section  17 . Therefore, it is possible to see the display screen  12  from outside even in the opened state. 
   The state as shown in  FIGS. 1 and 2  is referred to as “overlapping state” or “closed state”, while the state as shown in  FIGS. 3 and 4  is referred to as “opened state”. It is referred to as “opening action” to bring the overlapping type mobile telephone  30  from the “closed state” into the “opened state”, and referred to as “closing action” to bring the overlapping type mobile telephone  30  from the “opened state” into the “closed state”. 
   Next, the main operation section  17 , the side key  42  and the three way lever key  44 , and so on will be explained. As shown in  FIG. 3 , in the superposition type mobile telephone  30 , the cursor key  18  and the ten keys  20  in the main operation section  17  of the second housing  34  can be operated in the opened state of the first housing  32  and the second housing  34 . In order to prevent miss operation in this state, the side key  42  and the three way lever key  44  should be inoperative by control. 
   As shown in  FIG. 4 , the overlapping type mobile telephone  30  includes a camera  46 , a mirror  48  and a microphone  50  for image recording on its back face. The camera  46  and the microphone  50  can be operated in the closed state or the opened state. 
   As shown in  FIG. 5 , the three way lever key  44 , which is used in the closed state can be tilted upward (in the direction of an arrow mark “c”), can be tilted downward (in the direction of an arrow mark “d”) and also can be pushed toward center (in the direction of an arrow mark “e”). 
   In a standby mode in the closed state, when a menu selecting screen  22  as shown in  FIG. 18  is displayed on the display screen  12 , the three way lever key  44  may be tilted in the direction of the arrow mark “c” or in the direction of the arrow mark “d” to select an item. Next, when the three way lever key  44  is pushed toward center (in the direction of the arrow mark “e”), the selected item is started. 
   The side key  42 , shown in  FIG. 1 to 4 , can be pushed into the first housing  32  to cancel the selection of the item selected by operating toward center the three way lever key  44 . Such cancellation would make the display screen  12  go back to the previous image. 
     FIG. 6  is a block diagram showing a circuit of the overlapping type mobile telephone  30 . A rotation detecting section  64  detects, as shown in  FIG. 7 , the closed state, the opened state, a state (B 1  state in  FIG. 7 ) that the first housing  32  rotates clockwise at an angle of 90° from the closed state, and a state (B 2  state in  FIG. 7 ) that the first housing  32  rotates counterclockwise at an angle of 90° from the closed state on the basis of the state of the first housing  32 . The rotation detecting section  64  outputs to a CPU  62  (control section) a signal corresponding to the detected state. A volume resistance, a mechanical switch, or a sensor can be used as the rotation detecting section  64 . 
   The CPU  62  judges whether the overlapping type mobile telephone  30  is in the closed state or in the opened state, or the rotation direction of the first housing  32  upon reception of the signal from the rotation detecting section  64 . 
   For example, when the overlapping type mobile telephone  30  is in the closed state, in the case that a user performs the clockwise opening operation, the rotation detecting section  64  detects the state of the first housing  32  in the following order: the closed state, the B 1  state, and the opened state. The rotation detecting section  64  outputs the corresponding signals to the CPU  62 . Therefore, on the basis of these signals, the CPU  62  can judge that the first housing  32  rotated clockwise from the closed state and the overlapping type mobile telephone  30  is in the opened state. 
   Further, in the case that the user performs the counterclockwise opening operation, the rotation detecting section  64  detects the state of the first housing  32  in the following order: the closed state, the B 2  state, and the opened state. The CPU  62  can judge that the first housing  32  rotates counterclockwise from the closed state and the overlapping type mobile telephone  30  is in the opened state on the basis of corresponding signals output from the rotation detecting section  64 . 
   Similarly, when the overlapping type mobile telephone  30  is in the opened state, in the case that the user performs the clockwise or counterclockwise closing operation, the rotation detecting section  64  detects the state of the first housing  32  in the following order: the opened state, the B 2  state, and the closed state; or the opened state, the B 1  state, and the closed state. The CPU  62  can judge that the first housing  32  rotates clockwise or counterclockwise from the opened state and the overlapping type mobile telephone  30  is in the closed state. 
   Further, the CPU  62 , in addition to the judging of the state and the rotation direction of the first housing  32 , performs the control of the display section  11 , the main operation section  17 , the side key  42  and three direction lever  44  as the auxiliary operation section, a ROM  66 , a RAM, and a radio section  70  connected to an antenna portion  72  thereby to execute various functions. 
   An application (software) started on the basis of the judgment of the state and the rotation direction of the first housing  32  by the CPU  62 , and other applications are stored in the ROM  66 . Data of whether the first housing  32  is in the closed state or in the opened state is stored in the RAM  68 . The radio section  70  and the antenna portion  72  are used for communication with a base station by radio. 
   Next, the operation of the overlapping type mobile telephone  30  will be described.  FIGS. 8 to 16  are diagrams for explaining various embodiments with reference to various screens  80  to  132  displayed on the display screen  12  by the operation of the overlapping type mobile telephone  30 . 
   With reference to  FIG. 8 , a first example of the overlapping type mobile telephone  30  will be described. A display of an address book screen  82  is obtained by performing the clockwise opening operation from a state having a standby mode screen  80  displayed in the closed state. A display of a menu selecting screen  84  is obtained by performing the counterclockwise opening operation. 
   In the case that time more than a fixed time has passed with the overlapping type mobile telephone  30  not operated in the closed state, the standby mode screen  80  is displayed on the display screen  12 . In a lower portion  80   a  of the standby mode screen  80 , a guide is displayed, which indicates that the address book screen  82  is displayed by the clockwise opening operation, and the menu selecting screen  84  is displayed by the counterclockwise opening operation. 
   In the case that the user performs the clockwise opening operation from this state, the rotation detecting section  64  detects this operation and outputs a signal corresponding to this operation to the CPU  62  (refer to  FIG. 6 ). The CPU  62  judges that the telephone  30  has been put in the opened state by the clockwise rotation of the first housing  32  on the basis of this signal, and reads from the ROM  66  an application which is set to be started in the case that the telephone  30  has been put in the opened state by the clockwise rotation of the first housing  32  when the standby mode screen  80  is displayed in the closed state. 
   In the ROM  66 , an application of address book which is started in the case that the telephone  30  has been put in the opened state by the clockwise rotation is set. Therefore, the CPU  62  starts the application of address book on the basis of this setting and displays the address book screen  82  on the display screen  12 . 
   In the case that the user performs the counterclockwise opening operation from the state where the standby mode screen  80  is displayed on the display screen  12  in the closed state thereby to put the telephone  30  in the opened state, the rotation detecting section  64  detects this operation and outputs a signal corresponding to this operation to the CPU  62  (refer to  FIG. 6 ). The CPU  62  judges that the telephone  30  has been put in the opened state by the counterclockwise rotation of the first housing  32  on the basis of this signal, and reads from the ROM  66  an application which is set to be started in the case that the telephone  30  has been put in the opened state by the counterclockwise rotation of the first housing  32  when the standby mode screen  80  is displayed in the closed state. 
   An application of menu selecting screen  84  as shown in  FIG. 8  is set in the ROM  66 . Menu setting screen  84  is displayed in the case that the telephone  30  has been put in the opened state by the counterclockwise rotation. Therefore, the CPU  62  displays the menu selecting screen  84  on the display screen  12  on the basis of this setting. 
     FIG. 9  shows a second example. The second example is different from the first example in the following way. In the case that the user performs the counterclockwise opening operation from the state that a standby mode screen  86  is displayed in the closed state thereby to put the telephone  30  in the opened state, an application of mail may be started and an E-mail menu screen  90  may be displayed. 
   In the case that the application to be started is different from the application shown in  FIG. 8 , it is necessary to make guide display in a lower portion  86   a  of the standby mode screen  86  which is different from the guide display in the lower portion  80   a  of the standby mode screen  80  in  FIG. 8 . 
     FIG. 10  shows a third example that illustrates the case wherein after a specific name is selected from an address book screen  92  displayed on the display screen  12  in the closed state, automatic call-making by the clockwise opening operation is performed. The third example also illustrates the case wherein a mail creating screen  96  is displayed by the counterclockwise opening operation. 
   In the closed state, the user operates the side key  42  and the three way lever key  44  to display the address book screen  92  on the display screen  12 . At this time, in a lower portion  92   a  of the address book screen  92 , a guide is displayed, which indicates that automatic call-making is performed for telephone conversation in the case that the clockwise opening operation is performed after the specified name was selected, and that the mail creating screen  96  is displayed in the case that the counterclockwise opening operation is performed. 
   In the case that the user selects a name of “Dave Hindle” in the closed state and next performs the clockwise opening operation to put the telephone in the opened state, the rotation detecting section  64  detects this operation and outputs a signal corresponding to its operation to the CPU  62  (refer to  FIG. 6 ). The CPU  62  judges that the telephone  30  has been put in the opened state by the clockwise rotation from the closed state on the basis of this signal, and reads from the ROM  66  an application which is set so as to be started in the case that the telephone  30  has been put in the opened state by the clockwise rotation of the first housing  32  when the address book screen  92  is displayed in the closed state. 
   The application for automatic call-making by which a call is automatically made to the person selected from the address book screen  92  is set in the ROM  66 . Therefore, the CPU  62  reads out the stored telephone number of the person, “Dave Hindle” on the basis of this setting, and operates the radio section  70  thereby to cause a dialer to perform the automatic call-making. On the display screen  12 , a screen during call-making  94  is displayed. 
   In the case that the user selects a name of “Dave Hindle” from the address book screen  92  in the closed state and next performs the counterclockwise opening operation to put the telephone  30  in the opened state, the rotation detecting section  64  and the CPU  62  perform the operations similar to those in the case that the user performs the clockwise opening operation to put the telephone  30  in the opened state. An application for creating a mail is started, and a mail creating screen  96  is displayed on the display screen  12 . Further, “Dave Hindle”, which was selected from the address book screen  92 , is automatically indicated in the address. 
     FIG. 11  shows a fourth example. In the fourth example, after the specific name was selected from the address book screen  92  in the closed state, if the user performs the counterclockwise opening operation, a received mail box screen  102  of a mail application may be displayed, and heading of the mail received from the person selected on the address book screen  92  may be searched from the received mail box screen  102  and displayed. 
   In the examples shown in  FIGS. 8 to 11 , the specific examples are shown, in which the first housing  32  rotates in relation to the second housing  34  clockwise or counterclockwise from the closed state and they open, whereby the applications and the screens which are different from the applications and the screens which are operating in the closed state are started. In the overlapping type mobile telephone  30 , not only these applications and screens shown in the specific examples but also various other applications and screens can be started. 
   For example, in a fifth example shown in  FIG. 12 , in the case that the telephone  30  is put in the opened state by the clockwise opening operation from the state that the display section  12  displays a received mail box screen  104  in the closed state, an application for automatic call-making is started to automatically make a call to a sender of received mail, and a standby mode screen  106  during call-making is displayed. Further, in the case that the telephone  30  is put in the opened state by the counterclockwise opening operation, an application for mail is started to display a mail creating screen  108  for sending a mail to the sender of received mail. 
     FIG. 13  shows a sixth example. In the case that the telephone  30  is put in the opened state by the counterclockwise opening operation from the state that a received mail box screen  110  is displayed in the closed state, an application for a media player is started to reproduce a melody attached to the received mail, and a media player screen  114  is displayed. Further, in the case that the telephone  30  is put in the opened state by the clockwise opening operation from the state that the display section  12  displays a received mail box screen  110  in the closed state, an application for automatic call-making is started to automatically make a call to a sender of received mail, and a standby mode screen  106  during call-making is displayed. 
   In a seventh example shown in  FIG. 14 , in the case that the telephone  30  is put in the opened state by the clockwise opening operation from the state that an incoming call history screen  116  is displayed in the closed state, the application for the automatic call-making is started, a call is made to the sender recorded in the incoming-call history, and the screen during call-making  106  is displayed. In the case that the telephone  30  is put in the opened state by the counterclockwise opening operation, the application for the mail is started and the mail creating screen  108  to the sender of the received mail is displayed. 
   In an eighth example shown in  FIG. 15 , in the case that the telephone  30  is put in the opened state by the clockwise opening operation from the state that an image reproduction screen  122  is displayed in the closed state, an image editing screen  124  on which editing work such as addition of comment can be performed is displayed. Further, in the case that the telephone  30  is put in the opened state by the counterclockwise opening operation, an application for the mail is started, and a mail creating screen  126  about the mail to which an image is attached is displayed. 
   As shown in  FIGS. 12 to 15 , the first housing  32  rotates clockwise or counterclockwise from the closed state thereby to open the telephone  30 , whereby the various applications can be started and screens can be shown. In order to cause the user to recognize these advantages, guides corresponding to the applications and screens started by the opening operation are displayed on lower portions  104   a ,  110   a ,  116   a  and  122   a  of the received mail box screen  104 , the received mail box screen  110 , the incoming-call history screen  116  and the image reproduction screen  122  shown in  FIGS. 12 to 15 . 
   The specific examples in which the opening operation is performed from the closed state have been described in  FIGS. 8 to 15 . In the overlapping type mobile telephone  30 , the applications set in the ROM  66  is automatically started even in the case that the closing operation is performed from the opening state. 
   For example, as shown in a ninth example shown in  FIG. 16 , in the state that a mail creating screen  128  is displayed in the opened state, the clockwise closing operation is performed to put the telephone  30  in the closed state, whereby the camera function is started so that an image picked up by the camera can be displayed such as shown on a camera screen  130 . Further, the counterclockwise closing operation is performed to put the telephone in the closed state, whereby a GPS (Global Positioning System) screen  132  can be displayed. 
   Also in this case, in a lower portion  128   a  of the mail creating screen  128 , a guide is displayed, which indicates that the camera function is started by the clockwise closing operation, and the GPS function is started by the counterclockwise closing operation. 
   Regarding the various screens  80  to  132  shown in  FIGS. 8 to 16 , when the telephone  30  is put in the opened state from the closed state or when the telephone  30  is put in the closed state from the opened state, the upside of each screen on the display screen  12  is turned down. Therefore, in such a case, the display of the screen is naturally reversed at an angle of 180 degrees. 
   Regarding the various screens which have been described in each embodiment and denoted by the reference numerals  80  to  132 , that is, the standby mode screen, the address book screen, the menu selecting screen, the e-mail menu screen, the screen during call-making the mail creating screen, the received mail box screen, the media player screen, the incoming-call history screen, the image reproduction screen, the image editing screen, the camera screen, and the GPS screen, as long as screens are equivalent to these screens, names are not limited to these names, and the design of the screen is also not limited to the shown design. 
   Although the overlapping type portable terminal unit  30  having the two housings  32  and  34  has been shown in the above embodiment, the invention can be applied also to an overlapping type portable terminal unit having more than three housings on the basis of the similar technical idea. 
   Although the invention is applied to the mobile telephone in the above embodiment, it can be similarly applied to other portable terminal units such as the PDA. 
   As described above, according to the overlapping type portable terminal unit  30  of the invention, it is possible to make the first screen displayed in the display section in the case that the first housing  32  is rotated clockwise in relation to the second housing  34  differ from the second screen displayed in the display section in the case that the first housing  32  is rotated counterclockwise in relation to the second housing  34 . Therefore, since the various functions can be added to the opening and closing operations, the operability of the overlapping type portable terminal unit  30  can be improved. 
   Therefore, since the application and the screen can be selected and started by only the opening and closing operations of the first housing  32  and the second housing  34 , the operability of the overlapping type portable terminal unit  30  can be improved, and the operation for starting the desired application and screen can be simplified, so that the overlapping type portable terminal unit  30  of the invention is convenient. 
   Further, the operation by the opening or closing operation of the first and second housings  32  and  34  is entirely different from the operation by the ten keys  20  or the cursor key  18 , and the user can clearly distinguish the operation by the opening or closing operation from the operation by the ten keys  20  or the cursor key  18 . Therefore, the operability of the overlapping type portable terminal unit  30  can be further improved. 
   While a preferred embodiment of the invention has been described, various modifications will be apparent to one skilled in the art in light of this disclosure and are intended to fall within the scope of the appended claims.