Abstract:
A display device with automatically rotated images and a method thereof are provided. When the display device is rotated, the display device automatically switches the displaying direction of the image and maintains a sound output balance. A magnetic sensor is used to sense the change in magnetic flux generated when the display device is rotated, so as to sense the rotation of the display device. A microprocessor control unit (MCU) is used to determine the processing procedures for image and sound according to the change in the magnetic flux, and control the outputting of image and sound together with the processing procedures, so as to adjust the image and sound after the displaying image has been rotated.

Description:
[0001]     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 094146854 filed in Taiwan, R.O.C. on Dec. 27, 2005, the entire contents of which are hereby incorporated by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of Invention  
         [0003]     The present invention relates to a display device, and more particularly, to a display device for automatically switching the image and maintaining the sound balance when the display device is rotated.  
         [0004]     2. Related Art  
         [0005]     With the development of displaying technology, liquid crystal display (LCD) has become a mainstream technique for the screen of the desktop computer and liquid crystal TV, and also occupies an important position at the displaying for the notebook computer and cell phone. The developing of LCD not only focuses on enhancing the response speed and viewing angle and enlarging the size of the display panel, but also involves in TV application and has a multi-channel sound system, which has become a video/audio multimedia appliance with computer mode and television mode. Furthermore, as for the developing of other functions, e.g., freely rotating the screen allows the displaying image to rotate automatically along with the rotation of the display, such that the user dose not have to frequently scroll the webpage when browsing the webpage, designing diagrams or tables, thus providing convenience and enhancing the efficiency of using the space of the screen.  
         [0006]     As for the conventional art of automatically rotating the displaying image, e.g., ROC Patent Gazette Publication No. 00440786 entitled “Automatically rotated display device” filed on 16 Jun., 2001, wherein a sensor is used to sense the horizontal displacement and vertical displacement of the display, a horizontal sensing signal and a perpendicular sensing signal are generated respectively by the two displacements, a direction-displaying data is generated by a microprocessor through a predetermined program according to the two sensing signals, and a direction-controlling data is generated by a display controller, so as to control the displaying direction of the image. However, as for the method of controlling the displaying direction of the image by sensing the relative displacement of the display, the problem that the sensing speed restricts the displaying speed occurs, and also, the mechanical jittering causes errors in sensing the displacement.  
       SUMMARY OF THE INVENTION  
       [0007]     In view of the above problem, the present invention discloses a display device with automatically rotated images and a method thereof, wherein after the display is rotated, the image is automatically rotated without sensing the displacement of the display.  
         [0008]     The display device with automatically rotated images provided in the present invention comprises a magnetic sensor, a microprocessor control unit (MCU) and a displaying control unit.  
         [0009]     The technical method of using the display device of the present invention comprises the following steps. The magnetic sensor is used to sense the change in magnetic flux when the display device is rotated, and send out a sensing signal to the MCU according to the change in the magnetic flux, so as to tell it about the rotating angle. Next, the MCU generates a displaying direction signal through a predetermined program according to the sensing signal and then transfers the displaying direction signal to the displaying control unit. The displaying control unit generates a displaying control message for controlling the rotating of the displaying image. Furthermore, when the display device is rotated, the image is divided by a software technique, thus different divided images can be used to display different images. On the other aspect, the display device further comprises four loudspeakers spaced by a fixed distance, and as the image rotates, the loudspeakers are switched to maintain the left and right sound channels to be unchanged.  
         [0010]     In summary, the device and method disclosed in the present invention adjust the image and sound by sensing the change in the magnetic flux for the display device, and the efficiency of using the screen space is achieved through software technique.  
         [0011]     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The present invention will become more fully understood from the detailed description given herein below for illustration only, and which thus is not limitative of the present invention, and wherein:  
         [0013]      FIG. 1  is a block diagram of the function of a display device with automatically rotated images according to the present invention.  
         [0014]      FIG. 2  is a schematic view of the Hall effect.  
         [0015]      FIG. 3  is a predetermined program of the MCU according to the present invention.  
         [0016]      FIG. 4  is a block diagram of the function of another preferable display device with an automatically rotated image according to the present invention.  
         [0017]      FIG. 5A  is an appearance view of the display device before being rotated according to the present invention.  
         [0018]      FIG. 5B  is an appearance view of the display device after being rotated according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Referring to  FIG. 1 , it is a block diagram of the function of a display device  10  with an automatically rotated image according to the present invention. The display device  10  has a screen of 16:9, and has a computer input/output mode, a television or another video input/output mode that can be performed at the same time. When the display device  10  is not rotated, the horizontally displayed image for the display device  10  presents a length to width ratio of 16:9 (of course, the present invention is also applicable in a display device with a screen of 16:10). The display device  10  comprises a magnetic sensor  110 , a microprocessor control unit (MCU)  120 , a memory unit  130 , a control unit  140 , and a display unit  150 . The magnetic sensor  110  is electrically connected to the MCU  120 , the MCU  120  is respectively electrically connected to the magnetic sensor  110 , the memory unit  130  and the control unit  140 , and the control unit  140  is electrically connected to the display unit  150 .  
         [0020]     The magnetic sensor  110  is a sensor based upon the Hall effect principle. Referring to  FIG. 2 , it is a schematic view  20  of the Hall effect. By rotating a positive magnetic pole  211  and a negative magnetic pole  212 , the magnetic flux in the magnetic field passing through the Hall element  213  is changed, such that the Hall effect is generated. A Hall voltage is produced by sensing the magnetic flux, which is represented by the following Equation (1): 
 
 V   H   =R   H   IB/d    (1). 
 
         [0021]     In Equation (1), V H  represents the Hall voltage; R H  represents the Hall constant; I represents the current passing through the Hall element  213 ; B represents the sensed magnetic flux; and d represents the thickness of the Hall element  213 .  
         [0022]     When the display device  10  is rotated, the positive magnetic pole  211  and the negative magnetic pole  212  are driven to rotate, and the Hall element  213  maintains at the original position, so as to sense the change in the magnetic flux B, and generate a Hall voltage V H .  
         [0023]     The magnetic sensor  110  provides the Hall voltage V H  according to the sensing signal  911 , and outputs the sensing signal  911  to the MCU  120 . The MCU  120  quantifies the Hall voltage V H  represented by the sensing signal  911  into a first magnetic flux T′, i.e., corresponding magnetic flux variation. With respect to the first magnetic flux T′, a second magnetic flux T is stored within the memory unit, which is a standard quantity for the MCU  120  to determine whether to rotate the image or not, or a magnetic flux threshold quantity. The MCU  120  determines whether to rotate the image or not through a predetermined program  30  (referring to  FIG. 3 ) according to the first magnetic flux T′ and the second magnetic flux T. If it is determined to rotate the image, the MCU  120  generates a direction signal  912  and outputs it to the control unit  140 , the control unit  140  generates an image control signal  913  according to the direction signal  912  and outputs the image control signal  913  to the display unit  150 , and the display unit  150  completes the rotating of the image according to the image control signal  913 .  
         [0024]     Referring to  FIG. 3 , it shows the predetermined program  30  of the MCU  120 . The predetermined program  30  is executed by the MCU  120 , which comprises the following steps: receiving and quantizing the sensing signal  911  to obtain the first magnetic flux T′ (Step  301 ); retrieving the second magnetic flux T (Step  302 ); comparing the magnetic flux T′ with the second magnetic flux T (Step  303 ); if the first magnetic flux T′ is larger or equal to the second magnetic flux T, the MCU  120  generating the direction signal  912  and outputting it to the control unit  140 , and then, entering into the block of ending the program (Step  304 ); if the first magnetic flux T′ is smaller than the second magnetic flux T, entering into the block of ending the program (Step  305 ); and finally ending the program (Step  306 ).  
         [0025]     Thus, when the first magnetic flux T′ is larger than or equal to the second magnetic flux T, the control unit  140  generates the displaying control signal  913  according to the direction signal  912  output by the MCU  120 , so as to make the display unit  150  rotate the image. However, when the first magnetic flux T′ is smaller than the second magnetic flux T, the image is not rotated.  
         [0026]     In this embodiment, the proportional allocation of the length and width for the image and the allocation of the displaying district are achieved by software technique after the image has been rotated. That is, when the display device  10  is rotated, the image is not only rotated, but can also be shown with a length and width ratio of 9:16, or maintaining the length and width ratio of 16:9. As for the former circumstance, the area occupied by the image is possibly the whole screen or reduced to a part of the area in the screen, and as for the later circumstance, in order to allow the image to maintain the length and width ratio of 16:9, the area occupied by the image must be reduced to a part of the area in the screen. Combining the above two circumstances, if the image after being rotated is reduced to a part of the area in the screen, the remaining part can be further used for other applications. For example, if the original image is an image in the television input/output mode, and the image after being rotated is reduced to maintaining the length and width ratio of 16:9 and located at the central part or the upper or lower part of the screen, the remaining area can be used for displaying image at a computer or other video input/output mode, that is, a dual mode is performed. Or otherwise, the remaining area can be used to display an electronic program guide (EPG), which is a man machine interface (MMI) for a wireless digital television. After the length and width ratio of the image after being rotated and the allocation and application of the displaying area are determined through the software technique, the software technique may be embedded into the MCU  120 , such that the MCU  120  generates the direction signal  912  in accordance with the allocation made through the software technique, and outputs the direction signal  912  to the control unit  140 .  
         [0027]     Referring to  FIG. 4 , it is a block diagram of the function of the display device  40  with an automatically rotated image according to another preferred embodiment of the present invention. The display device  40  has a screen of 16:9, and has both the computer input/output mode and the television or another video input/output mode that can be performed at the same time. When the display device  40  is not rotated, the horizontally displayed image for the display device  40  presents a length and width ratio of 16:9 (Of course, the display device with a screen of 16:10 also may be used). The display device  40  comprises a magnetic sensor  410 , an MCU  420 , a memory unit  430 , a control unit  440 , a display unit  450 , and a loudspeaker unit  460 . The magnetic sensor  410  is electrically connected to the MCU  420 , the MCU  420  is respectively electrically connected to the magnetic sensor  410 , the memory unit  430  and the control unit  440 , and the control unit  440  is respectively electrically connected to the display unit  450  and the loudspeaker unit  460 .  
         [0028]     When the display device  40  is rotated, the magnetic sensor  410  senses the rotation of the display device  40  and generates a Hall voltage V H , and the sensing signal  941  for representing the Hall voltage V H  is output to the MCU  420 . The MCU  420  quantizes the Hall voltage V H  represented by the sensing signal  941  into a first magnetic flux T′, which is a corresponding magnetic flux variation. With respect to the first magnetic flux T′, a second magnetic flux T is stored within the memory unit, which is a standard quantity for the MCU  420  to determine whether to rotate the image or not, or a magnetic flux threshold quantity. The MCU  420  determines whether to rotate the image or not through a predetermined program  30  according to the first magnetic flux T′ and the second magnetic flux T. If it is determined to rotate the image, the MCU  420  generates a direction signal  942  containing an image direction message and a sound channel direction message, and outputs the direction signal  942  to the control unit  440 . The control unit  440  generates an image control signal  943  and a sound channel control signal  944  according to the direction signal  942 , and outputs them to the display unit  450  and the loudspeaker unit  460  respectively. The display unit  450  rotates the image according to the image control signal  943 , and after the image is rotated, the proportional allocation of the length and width and the allocation of the displaying area are achieved by the MCU  420  together with a software technique. The loudspeaker unit  460  adjusts the output of sound according to the sound channel control signal  944 . The proportional allocation of the length and width and the allocation of the displaying area achieved through the predetermined program  30  together with the software technique has already been illustrated in the former embodiment, thus will not be described herein any more.  
         [0029]     Referring to both  FIG. 5A  and  FIG. 5B ,  FIG. 5A  is an appearance view  50  of the display device  40  before being rotated according to the present invention.  FIG. 5B  is an appearance view  51  of the display device  40  after being rotated according to the present invention. The loudspeaker unit  460  of the display device  40  comprises a first loudspeaker  561 , a second loudspeaker  562 , a third loudspeaker  563 , and a fourth loudspeaker  564 , which are disposed together as a square and spaced with an equal distance between each other, and each of them outputs sounds with each of the sound channels.  
         [0030]     As shown in  FIG. 5A , when the display device  40  is not rotated, the first sound channel  571  is implemented by the first loudspeaker  561 , the second sound channel  572  is implemented by the second loudspeaker  562 , the third sound channel  573  is implemented by the third loudspeaker  563 , and the fourth sound channel  574  is implemented by the fourth loudspeaker  564 . As shown in  FIG. 5B , when the display device  40  is rotated in an anti-clockwise direction, the second sound channel  572  is implemented by the first loudspeaker  561 , the third sound channel  573  is implemented by the second loudspeaker  562 , the fourth sound channel  574  is implemented by the third loudspeaker  563 , and the first sound channel  571  is implemented by the fourth loudspeaker  564 . When the control unit  440  outputs the sound channel control signal  944  to the loudspeaker unit  460 , the above switching process is performed swiftly by a logic gate, thus, the interruption of the sounds cannot be distinguished by human ear. Furthermore, since the loudspeakers are arranged as a square, the sound field achieved after the sounds are converted maintains.  
         [0031]     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.