Abstract:
An information processing apparatus equipped with an interface for connection to an external display device and comprises an internal display device, and an operating button. The apparatus further comprises a processor which is responsive to an operation of the operating button and drives a plurality of display devices including the internal display device and the external display device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-333893, filed Nov. 18, 2002, the entire contents of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to an information processing apparatus equipped with an interface for connection to an external display device and a display switching method.  
           [0004]    2. Description of the Related Art  
           [0005]    A conventional method of switching computer display devices involves specifying and making display switching by using a hot key or screen properties (see, for example, Japanese Unexamined Patent Publication No. 7-13531).  
           [0006]    With the conventional technique, however, in the case of a simultaneous display mode in which the same image is displayed on two or more display devices, a plurality of actions (input operations) is required both in switching into the simultaneous display mode and in canceling the simultaneous display mode, leading to a problem of operability.  
           [0007]    Also, setting a multi-monitor (multi-display) mode which different images are displayed on two or more display devices needs complex select operations and setting operations, such as open screen properties, click a setting tab, select monitor devices, set up the monitor devices, press the OK button, etc. In this case as well, therefore, there arises a problem of operability.  
           [0008]    Thus, the conventional methods for setting the simultaneous display mode and the multi-monitor display mode suffer from a problem of operability.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    According to an embodiment of the present invention, an information processing apparatus which is equipped with an interface for connection to an external display device and comprises an internal display device, an operating button, a processor which is responsive to an operation of the operating button and drives a plurality of display devices including the internal display device and the external display device.  
           [0010]    According to another embodiment of the present invention, a display device switching method for use with an information processing apparatus equipped with an interface for connection to an external display device, the method comprises switching from a process of driving plural display devices including the external display device to a process of driving a single display device and vice versa each time an operating button of the information processing apparatus is operated.  
           [0011]    Additional objects and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.  
           [0012]    The objects and advantages of the present invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0013]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present invention in which:  
         [0014]    [0014]FIG. 1 is a diagram for use in explanation of switching operations and the operating procedure for the simultaneous display mode;  
         [0015]    [0015]FIG. 2 is a diagram for use in explanation of switching operations and the operating procedure for the multi-monitor display mode;  
         [0016]    [0016]FIG. 3 is an exterior view of an information processing apparatus according to an embodiment of the present invention;  
         [0017]    [0017]FIG. 4 is a block diagram of a system configuration of the information processing apparatus of FIG. 3;  
         [0018]    [0018]FIG. 5 shows an example of a user interface screen of the information processing apparatus of FIG. 3; and  
         [0019]    [0019]FIG. 6 is a flowchart illustrating the display device switching procedure in the information processing apparatus of FIG. 3. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    An embodiment of an information processing apparatus according to the present invention will now be described with reference to the accompanying drawings.  
         [0021]    First, an outline of the embodiment of the present invention will be given with reference to FIGS. 1 and 2.  
         [0022]    [0022]FIGS. 1 and 2 illustrate operating procedures in the embodiment of the present invention. The embodiment will be described in terms of a portable personal computer configured such that the display unit casing can be rotated through a given angle with respect to the keyboard on the body. In the display unit casing an LCD-based display device (hereinafter referred to as an internal display device) is housed. The body of the personal computer is equipped with an interface for connection to an external display device such as a CRT. An operating button (hereinafter referred to as a presentation button) dedicated to switching between the display modes is provided on the top of the computer body on which the keyboard is situated. Although the embodiment is described as using an LCD as the internal display device and a CRT as the external display device, this is not restrictive. For example, it is also possible to connect an LCD-based display device as the external display device through a DVI (Digital Video Interface).  
         [0023]    [0023]FIG. 1 shows operations and the switching procedure when the presentation button is allocated a function of switching from the sole display mode in which the LCD as the internal display device is solely driven to display an image to the simultaneous display mode in which the same image is displayed on two or more display devices.  
         [0024]    One-time depressing (one-touch operation) the presentation button in the sole display mode allows switching into the simultaneous display mode in which the same image is displayed on the LCD and the CRT as the external display device. When the presentation button is depressed again in the simultaneous display mode, a display mode is returned to the sole display mode in which only the LCD as the internal display device is active.  
         [0025]    [0025]FIG. 2 shows operations and the switching procedure when the presentation button is allocated a function of switching from the sole display mode to the multi-monitor display mode and vice versa.  
         [0026]    One-time depressing the presentation button in the sole display mode in which the LCD as the internal display device is solely driven allows switching into the multi-monitor display mode in which the LCD and the CRT as the external display device display different images. When the presentation button is depressed again in the multi-monitor display mode, a display mode is returned to the sole display mode in which only the LCD as the internal display device is active.  
         [0027]    Thus, each time the presentation button is depressed, switching is made from the sole display mode to the simultaneous display mode or the multi-monitor display mode and vice versa. By having means for allowing the presentation button to have a function of instructing switching from the sole display mode to the simultaneous display mode or the multi-monitor display mode, the display mode switching function shown in FIG. 1 and the display mode switching function shown in FIG. 2 can be selectively performed. The embodiment of the present invention to be described later is provided with a user interface that allows the allocation of such a function (simultaneous display/multi-monitor display) to the presentation button.  
         [0028]    The embodiment of the present invention which implements the display switching function shown in FIGS. 1 and 2 will now be described with reference to FIGS. 3 through 6.  
         [0029]    [0029]FIG. 3 is a perspective view illustrating the exterior of the information processing apparatus embodying the present invention. The embodiment will be described taking a notebook personal computer by way of example.  
         [0030]    A computer, indicated at  100 , has a computer body  110  and a display unit (casing)  120 . An external display device  200 , such as a CRT, may be connected to the computer body  110  through an interface for connection to an external display device which will be described later.  
         [0031]    The display unit  120  has an LCD-based display device built in as an internal display device  121 . The display unit  120  is mounted on the computer body  110  so as to be rotatable between the open position and the closed position.  
         [0032]    The computer body  110  has a housing in the shape of a thin box. The keyboard  111  is placed on the top of that housing. Armrests are formed in front of the keyboard  111  on the top of the housing. A touch panel  112  is provided in substantially the middle between the armrests. An operating button (hereinafter referred to as a presentation button)  115  which is dedicated to instruct switching between display modes is provided on the top of the housing on which the keyboard  111  is situated.  
         [0033]    [0033]FIG. 4 shows, in block diagram form, the system configuration of the computer shown in FIG. 3. The computer system, which is a battery-driven notebook personal computer easy to carry, includes a CPU  11 , a graphic/memory controller hub  12 , a memory  13 , a graphics controller  14 , a VRAM  141 , an I/O hub  15 , a BIOS-ROM  16 , a hard disk driver (HDD)  17 , a sound controller  18 , an embedded controller (EC)  19 , and a keyboard  20 .  
         [0034]    The graphics controller  14  controls the internal display device (LCD)  121  and external display devices connected to the computer body through interfaces for connection to external display devices, such as a CRT terminal  142 , a DVI terminal  143  and a TV (television) terminal  144  under the control of the OS executed by the CPU  11 .  
         [0035]    The embedded controller (EC)  19  issues a request for display switching to the CPU  11  when the presentation button  115  is depressed.  
         [0036]    The CPU  11  carries out various processes according to the operating system (OS), application programs and utility programs loaded from the hard disk drive (HDD)  17  into the main memory  13 . In this embodiment, upon reception of the display switching request from the embedded controller (EC)  19 , the CPU  11  issues a display switching command to the graphics controller  14  under the control of the OS.  
         [0037]    Upon reception of the display switching command from the CPU  11  via the graphic/memory controller hub  12 , the embedded controller (EC)  19  executes such processing of switching display modes as shown in FIG. 6.  
         [0038]    [0038]FIG. 5 shows an example of a user interface screen  500  for selecting and setting a function to be allocated to the presentation button  115 . Here, a selection is made from four simultaneous display (same image) functions of different resolutions and a multi-monitor (different images) display function and the selected function is allocated to the presentation button  115 .  
         [0039]    [0039]FIG. 6 is a flowchart illustrating the display device switching procedure carried out by the embedded controller (EC)  19  when the presentation button  115  is depressed.  
         [0040]    The operation of the embodiment of the present invention will be described with reference to the drawings thus far described.  
         [0041]    To the computer body  110  is connected an external display device  200  through an interface ( 142 ,  143 ,  144 ) for connection to an external display device. Of various external display devices (CRT, LED, television set) which can be connected to the interfaces  142 ,  143 , and  144 , the CRT is connected to the computer body  110  through the interface  142  as the external display device  200 .  
         [0042]    Using the user interface screen shown in FIG. 5, an arbitrary one is selected from the four types of simultaneous display (same image) functions different in resolution and the multi-monitor (different images) display function and then allocated to the presentation button  115  provided on the console panel of the computer body  110 . Here, the operation when the button is allocated a simultaneous display function (see FIG. 1) and the operation when the button is allocated the multi-monitor display function (see FIG. 2) will be described.  
         [0043]    When the presentation button  115  is one-touch depressed, the embedded controller (EC)  19  presents a request for switching display modes to the CPU  11 .  
         [0044]    Upon reception of the display switching request from the embedded controller (EC)  19 , the CPU  11  issues a display switching command to the graphics controller  14  under the control of the OS.  
         [0045]    Upon reception of the display switching command from the CPU  11  via the graphic/memory controller hub  12 , the embedded controller (EC)  19  executes such processing of switching display modes as shown in FIG. 6.  
         [0046]    When the presentation button  115  is depressed once, property information is first acquired which is used to make a determination of which function has been allocated to the presentation button  115  (step S 11 ). Then, various items of device information required to switch display modes, such as current display device status and display state, are acquired (step S 12 ) and the function (the effective function) allocated to the presentation button  115  is determined on the basis of the property information (step S 13 ).  
         [0047]    If the simultaneous display (the same image) function has been allocated to the presentation button  115  (NO in step S 13 ), then various setting operations for the simultaneous display (setting the display timing, setting up a display device which is a candidate for simultaneous display, setting the resolution, etc.) are performed (steps S 31 , S 32  and S 33 ). Thus, the external display device (CRT)  200  is enabled to display the same image as the internal display device (LCD)  121 .  
         [0048]    If, on the other hand, the presentation button  115  has been allocated the multi-monitor (different images) display function (YES in step S 13 ), then it is determined whether or not the current display mode is the multi-monitor display mode (step S 14 ). If the result is the multi-monitor display mode (YES in step S 14 ), then the multi-monitor display mode is canceled and a display mode is returned to the display mode using the internal display device (LCD) only (step S 15 ). If the current display mode is not the multi-monitor display mode (that is, only the internal display device (LCD)  121  is placed in the display state) (NO in step S 14 ), a currently connected external display device is identified and multi-monitor display control is performed on that display device. Here, as the external display device  200 , the CRT display is connected to the interface  142  of the computer body  110  and hence the multi-monitor display control is performed on the CRT display (step S 21 ).  
         [0049]    Thus, merely repeating one-touch operation of the presentation button  115  allows switching into the simultaneous display mode or the multi-monitor display mode to be made quickly with a simple operation, significantly improving operability.  
         [0050]    While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.  
         [0051]    For example, although the embodiment has been described as using the presentation button  115  both in switching into the simultaneous display mode and in switching into the multi-monitor display mode, a dedicated switching button may be provided for each of the simultaneous display mode and the multi-monitor display mode. Alternatively, a multifunction button and a dedicated button may be used in combination.