Abstract:
An electrical device capable of auto-adjusting display direction according to a tilt of a display is provided. The electrical device includes a housing, a display panel installed on the housing, a gravity sensor for outputting a sensing parameter based on a tilt angle of the display panel, a direction control device for generating direction signals, and a micro-controller for adjusting the display direction of the display panel based on the sensing parameter and for adjusting the indicated direction corresponding to direction signals generated by the direction control device.

Description:
BACKGROUND OF INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an electrical device, and more specifically, to an electrical device capable of auto-adjusting the displayed image direction based on the rotation of the display panel.  
         [0003]     2. Description of the Prior Art  
         [0004]     In the modern information era, personal computers (PCs) have become essential individual tools. Conventional desktop PCs, due to their larger volume and heavy weight, are not suitable to be carried around. Conversely, the hand-held electrical devices with smaller volume and light weight, such as notebook PCs, personal digital assistants (PDAs) and tablet PCs, are more popular to users for looking up, viewing, or storing an amount of data.  
         [0005]     Please refer to  FIG. 1 , which shows a conventional portable computer  10 . The portable computer  10  comprises a housing  11 , a touch panel  12  and a direction control device  14 . The portable computer  10  usually uses a user interactive touch display panel functioning as an interface between a user and the portable computer  10  to display digital data on a large-area screen. The display panel  12  functions as a touch panel for sensing a position of pressure exerted by a user for controlling the portable computer  10  according to different pressure positions within the touch panel. Furthermore, due to advancement of handwriting identification technology, the user can directly press the display panel  12  or use a touch pen  18  to write down information when the user wishes to input the information to the portable computer  10 . Therefore, the portable computer  10  can identify the information inputted by the user according to write-traces of the user detected by the display panel  12  so as to input the information to the portable computer. The handwriting input can not only reduce space occupied by the portable computer  10 , but also supply a better interface so that the user can control the portable computer  10  via the display panel  12 . In addition, the user can control the direction of the displayed image on the display panel  12  by means of the direction control device  14 .  
         [0006]     Please refer to  FIG. 2 , which shows a graph of the portable computer  10  depicted in  FIG. 1  rotating 90 degrees. The display panel  12  just displays narrow width images. For example, as shown in  FIG. 1 , for an image  15  having a broad width (that the image  15  shows the word “CAT”), the portable computer  10  fails to display the image  15  completely. Therefore, the user can manipulate the direction control device  14  to move the image  15 , so that the non-displayed part of the image  15  can be displayed. Meanwhile, on account of the fixed size of the display panel  12 , part of original visible image  15  will be hidden. If the user rotates the portable computer  10  by 90 degrees from the status of  FIG. 1  to that of  FIG. 2 , the display panel  12  can show broader width. Nevertheless, the user must adjust the displayed direction manually, which is very inconvenient for user.  
       SUMMARY OF INVENTION  
       [0007]     It is therefore an objective of the claimed invention to provide an electrical device capable of auto-adjusting the displayed image direction based on the rotation of the display panel, in order to solve the above-mentioned problems.  
         [0008]     According to the claimed invention, an electrical device capable of auto-adjusting display direction according to a tilt of a display comprises a housing, a display panel installed on the housing, a gravity sensor for outputting a sensing parameter based on a tilt angle of the display panel, a direction control device for generating direction signals, and a micro-controller for adjusting the display direction of the display panel based on the sensing parameter and for adjusting the indicated direction corresponding to direction signals generated by the direction control device.  
         [0009]     These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the embodiment, which is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0010]      FIG. 1  shows a conventional portable computer.  
         [0011]      FIG. 2  shows a graph of the portable computer depicted in  FIG. 1  rotating 90 degrees.  
         [0012]      FIG. 3  shows a portable computer positioned on a surface according to the present invention.  
         [0013]      FIG. 4  is a block diagram of the portable computer depicted in  FIG. 3 .  
         [0014]      FIG. 5  is a block diagram of the G sensor depicted in  FIG. 4 .  
         [0015]      FIG. 6  is a timing diagram of output voltage of the G sensor.  
         [0016]      FIGS. 7-10  show a schematic diagram of the portable computer depicted in  FIG. 3  at various situations corresponding to tilt angles sensed by the G sensor. 
     
    
     DETAILED DESCRIPTION  
       [0017]     Please refer to  FIG. 3  and  FIG. 4 .  FIG. 3  shows a portable computer  30  positioned on a surface  40  according to the present invention.  FIG. 4  is a block diagram of the portable computer  30  depicted in  FIG. 3 . The portable computer  30  comprises a housing  11 , a display panel  12  installed on the housing  11 , a direction control device  14  for generating direction signals, a micro-controller  34 , and a gravity sensor (G sensor)  32  installed within the housing  11 . The direction control device  14  is a set of four-direction buttons installed on the housing  11 , a joystick or a track ball connected to the connection port  36  on the housing  11 .  
         [0018]     Please refer to  FIG. 5  and  FIG. 6 .  FIG. 5  is a block diagram of the G sensor  32  depicted in  FIG. 4 .  FIG. 6  is a timing diagram of output voltage of the G sensor  32 . The G sensor  32  comprises an X-sensor  60 , a Y-sensor  62 , an oscillator  64 , two phase demodulators  66 , and a duty cycle modulator  68 . The oscillator  64  is used for generating signals having 90 degrees phase difference. The X-sensor  60  and the Y-sensor  62  are respectively used for sensing the tilt with respect to the x-coordinate and the y-coordinate and outputting various amplitude square waves based on the tilt angle. The phase demodulators  66  respectively coupled to the X-sensor  60  and the Y-sensor  62  are used for rectifying the square wave. The duty cycle modulator  68  transforms the rectified signal into a square wave with different duty cycles, as shown in  FIG. 6 . The square wave with 50% duty cycle (i.e. T1/T2=0.5 shown in  FIG. 6 ) indicates that the tilt angle φ x  sensed by the x-sensor  60  is 0 degrees, or the tilt angle φ y  sensed by the Y-sensor  62  is 90 degrees. When either the X-sensor  60  or the Y-sensor  62  senses the tilt angle, the duty cycle modulator  68  will output the voltage with various duty cycles at either of the output ends X out  or Y out .  
         [0019]     When the G sensor  32  as well as the display panel  12  is tilted, it can output voltages with different duty cycles based on different tilt angles. Therefore, the microcontroller  34  can determine the tilt angle of the display panel  12  based on the different output voltages.  
         [0020]     Please refer to  FIGS. 7-10 , which show a schematic diagram of the portable computer  30  depicted in  FIG. 3  at various situations corresponding to tilt angles sensed by the G sensor  32 . Suppose that the portable computer  30  is positioned on a surface  40  as shown in  FIG. 7  as the X-sensor  60  of the G sensor  32  senses the tilt angle φ x  is +90 degrees and the Y-sensor  62  senses the tilt angle φ y  is 0 degrees, i.e. horizontal. At this moment, the display panel  12  shows image (characters “CAT”)  50  under the first mode. If the portable computer  30  is rotated, as can be seen from  FIG. 8 , the X-sensor  60  senses that the tilt angle φ x  is 90 degrees and the Y-sensor  62  senses that the tilt angle φ y  is 0 degrees, i.e. horizontal. At this moment, the G sensor  32 , due to a change of the tilt angle φ x , will generate and output different duty cycle output voltages based on different tilt angle. The micro-controller  34  can determine the tilt angle of the display panel  12  based on the duty cycle of the output voltage and adjust the displayed direction of the display panel  12  and the direction signal generated by the direction control device  14  for controlling the moving direction of the displayed image on the display panel  12 . For example, as shown in  FIG. 7 , when triggering a “Left” button on the portable computer  30 , a direction signal used for controlling the image to move toward the direction of arrow  101  is generated. When triggering a “Right” button, a direction signal used for controlling the image to move toward the reverse direction of arrow  101  is generated. If the portable computer  30  is rotated, as shown in  FIG. 8 , triggering the “Left” button generates a direction signal used for controlling the image to move toward the reverse direction of arrow  101 . Conversely, triggering the “Right” button generates a direction signal used for controlling the image to move toward the direction of arrow  101 . Similarly, as shown in  FIG. 9 , the X-sensor  60  senses the tilt angle φ x  is 0 degrees i.e. horizontal, and the Y-sensor  62  senses the tilt angle φ y  is +45 degrees. In  FIG. 10 , the X-sensor  60  senses the tilt angle φ x  is 0 degrees i.e. horizontal, and the Y-sensor  62  senses the tilt angle φ y  is −45 degrees. Therefore, the micro-controller  34  can detect the different tilt angles φ x  and φ y  to determine the tilt of the display panel  12 , thereby adjusting the displayed image direction of the display panel  12  and the direction signals generated by the direction control device  14 .  
         [0021]     Briefly speaking, four control modes are defined by this embodiment portable computer  30 , each corresponding to a display direction of the display panel  12  and for moving the direction of the direction signals generated by the direction control device  14 . For example, suppose that when the portable computer  30  is placed as shown in  FIG. 7 , and the tilt angle φ x  transition is between 0 degrees and +90 degrees, the display panel  12  displays the image and the direction control device  14  is operated at a first control mode, as shown in  FIG. 7 . When the tilt angle φ x  transition is between 0 and 90 degrees, the microcontroller  34  change the portable computer  30  to the second control mode, in which the displayed image of the display panel  12  and the direction signals generated by the direction control device  14  are all the reverse of those under the first mode. Similarly, if the tilt angle φ y  is between +90 degrees and 0 degrees, as shown in  FIG. 9 , the display panel  12  and the direction control device  14  are operated under the third control mode set by the microcontroller  34 . If the tilt angle φ y  transition is between 0 and 90 degrees, the micro-controller  34  can adjust the display panel  12  and the direction control device  14  operated under the fourth mode, in which the displayed image of the display panel  12  and the direction signals generated by the direction control device  14  are all the reverse of those under the third mode.  
         [0022]     Please notice that, how large the tilt angles of φ x  or φ y  is required to switch the control modes can determined by the designer.  
         [0023]     The portable computer  30  can be a personal digital assistant (PDA), a tablet PC, a digital camera, or a digital camcorder.  
         [0024]     In contrast to prior art, the G sensor of the present invention portable computer can output a detecting voltage based on a tilt of the display panel. Based on the detecting voltage, the micro-controller can adjust the display direction of the display panel and the direction signals which are used for controlling the movement of displayed image. In doing so, the user can adjust the tilt of the display panel at random, and does not have to worry about inconsistently displayed images shown on the display panel.  
         [0025]     Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.