Abstract:
A display device includes a display unit having N adjustable screen resolutions; a storage unit storing a setting list, the setting list recording the N adjustable screen resolutions and N display ratio parameters; a processing unit retrieving a current screen resolution from the display unit and comparing the current screen resolution with the N adjustable screen resolutions, the processing unit selecting an i-th display ratio parameter corresponding to an i-th adjustable screen resolution from the N display ratio parameters when the current screen resolution is identical to the i-th adjustable screen resolution; and an image generating unit generating an image according to the i-th display ratio parameter and displaying the image in the display unit.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a display device and an image display method and, more particularly, to a display device and an image display method capable of displaying an image with a fixed size in different screen resolutions. 
         [0003]    2. Description of the Prior Art 
         [0004]    So far various display devices (e.g. computer screen, television, monitor, etc.) have anon screen display (OSD) function. In general, the OSD may render images corresponding to various parameters (e.g. brightness, contrast, color, volume, etc.) for a user to adjust on the screen. Furthermore, a display device may have a lot of screen resolutions (e.g. 800*600, 1024*768, 1600*900, etc.) for the user to adjust. To prevent an OSD image from enlarging, reducing and/or shifting due to different screen resolutions, some prior arts install a scaler in the display device, so as to display the OSD image with a fixed size at a fixed position in the display device. However, the scaler added to the display device will increase the manufacturing cost of the display device. 
       SUMMARY OF THE INVENTION 
       [0005]    The invention provides a display device and an image display method capable of displaying an image with a fixed size in different screen resolutions, so as to solve the aforesaid problems. 
         [0006]    According to the claimed invention, a display device comprises a display unit, a storage unit, a processing unit and an image generating unit. The display unit has N adjustable screen resolutions, wherein N is a positive integer larger than 1. The storage unit stores a setting list, the setting list records the N adjustable screen resolutions and N display ratio parameters, and each of the N adjustable screen resolutions is corresponding to one of the N display ratio parameters. The processing unit is electrically connected to the display unit and the storage unit. The processing unit retrieves a current screen resolution from the display unit and compares the current screen resolution with the N adjustable screen resolutions. The processing unit selects an i-th display ratio parameter corresponding to an i-th adjustable screen resolution of the N adjustable screen resolutions from the N display ratio parameters when the current screen resolution is identical to the i-th adjustable screen resolution, wherein i is a positive integer smaller than or equal to N. The image generating unit is electrically connected to the display unit and the processing unit. The image generating unit generates an image according to the i-th display ratio parameter and displays the image in the display unit. 
         [0007]    According to the claimed invention, the image has a fixed horizontal length and a fixed vertical length when the image is displayed in the display unit, each of the N display ratio parameters comprises a horizontal pixel amount per unit length and a vertical pixel amount per unit length, and the image generating unit multiplies the fixed horizontal length by the horizontal pixel amount per unit length of the i-th display ratio parameter and multiplies the fixed vertical length by the vertical pixel amount per unit length of the i-th display ratio parameter, so as to generate the image. 
         [0008]    According to the claimed invention, a horizontal distance is between a reference point of the image and a first edge of the display unit and a vertical distance is between the reference point of the image and a second edge of the display unit when the image is displayed in the display unit, the first edge is perpendicular to the second edge, and the image generating unit multiplies the horizontal distance by the horizontal pixel amount per unit length of the i-th display ratio parameter and multiplies the vertical distance by the vertical pixel amount per unit length of the i-th display ratio parameter, so as to display the image at a fixed position in the display unit according to the reference point. 
         [0009]    According to the claimed invention, the display device further comprises a button disposed at a periphery of the display unit, wherein the fixed position is corresponding to the button. 
         [0010]    According to the claimed invention, the display unit displays a setting interface for setting the fixed horizontal length and the fixed vertical length. 
         [0011]    According to the claimed invention, an image display method comprises steps of providing a setting list, wherein the setting list records N adjustable screen resolutions of a display unit and N display ratio parameters, each of the N adjustable screen resolutions is corresponding to one of the N display ratio parameters, and N is a positive integer larger than 1; retrieving a current screen resolution from the display unit; comparing the current screen resolution with the N adjustable screen resolutions; selecting an i-th display ratio parameter corresponding to an i-th adjustable screen resolution of the N adjustable screen resolutions from the N display ratio parameters when the current screen resolution is identical to the i-th adjustable screen resolution, wherein i is a positive integer smaller than or equal to N; generating an image according to the i-th display ratio parameter; and displaying the image in the display unit. 
         [0012]    According to the claimed invention, the image has a fixed horizontal length and a fixed vertical length when the image is displayed in the display unit, each of the N display ratio parameters comprises a horizontal pixel amount per unit length and a vertical pixel amount per unit length, and the image display method further comprises step of multiplying the fixed horizontal length by the horizontal pixel amount per unit length of the i-th display ratio parameter and multiplying the fixed vertical length by the vertical pixel amount per unit length of the i-th display ratio parameter, so as to generate the image. 
         [0013]    According to the claimed invention, a horizontal distance is between a reference point of the image and a first edge of the display unit and a vertical distance is between the reference point of the image and a second edge of the display unit when the image is displayed in the display unit, the first edge is perpendicular to the second edge, and the image display method further comprises step of multiplying the horizontal distance by the horizontal pixel amount per unit length of the i-th display ratio parameter and multiplying the vertical distance by the vertical pixel amount per unit length of the i-th display ratio parameter, so as to display the image at a fixed position in the display unit according to the reference point. 
         [0014]    According to the claimed invention, a button is disposed at a periphery of the display unit and the fixed position is corresponding to the button. 
         [0015]    According to the claimed invention, the image display method further comprises steps of displaying a setting interface in the display unit; and setting the fixed horizontal length and the fixed vertical length in the setting interface. 
         [0016]    As mentioned in the above, the invention makes the setting list in advance according to a plurality of adjustable screen resolutions of the display unit and then stores the setting list in the storage unit of the display device. When a user is going to show an OSD image or other images in the display unit, the invention will calculate the horizontal pixel amount and the vertical pixel amount, which are covered by the fixed horizontal length and the fixed vertical length of the image, according to the current screen resolution of the display unit and the setting list. Accordingly, the invention can display the image with a fixed size in the display unit in different screen resolutions, so as to prevent the image from enlarging or reducing due to different screen resolutions. Furthermore, the invention may set the reference point on the image and then calculates the horizontal pixel amount and the vertical pixel amount, which are covered by the horizontal distance and the vertical distance between the reference point of the image and the edges of the display unit, according to the current screen resolution of the display unit and the setting list. Accordingly, the invention can display the image with a fixed size at a fixed position in the display unit in different screen resolutions. The aforesaid fixed position may be corresponding to the button disposed at the periphery of the display unit, so as to prevent the image from shifting due to different screen resolutions. Moreover, the invention may display the setting interface, which is used for setting the fixed horizontal length and the fixed vertical length of the image, in the display unit. Accordingly, the user can modify the fixed horizontal length and the fixed vertical length of the image displayed in the display unit through the setting interface according to his/her preference. Since the invention displays the image with the fixed size in different screen resolutions through software without the scaler or other hardware of the prior art, the invention can further reduce the manufacturing cost. 
         [0017]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a functional block diagram illustrating a display device according to an embodiment of the invention. 
           [0019]      FIG. 2  is a schematic diagram illustrating the setting list shown in  FIG. 1 . 
           [0020]      FIG. 3  is a schematic diagram illustrating a screen displayed in the display unit shown in  FIG. 1  in a screen resolution. 
           [0021]      FIG. 4  is a schematic diagram illustrating a screen displayed in the display unit shown in  FIG. 1  in another screen resolution. 
           [0022]      FIG. 5  is a flowchart illustrating an image display method according to an embodiment of the invention. 
           [0023]      FIG. 6  is a schematic diagram illustrating a setting interface displayed in the display unit shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Referring to  FIGS. 1 to 5 ,  FIG. 1  is a functional block diagram illustrating a display device  1  according to an embodiment of the invention,  FIG. 2  is a schematic diagram illustrating the setting list  120  shown in  FIG. 1 ,  FIG. 3  is a schematic diagram illustrating a screen  100  displayed in the display unit  10  shown in  FIG. 1  in a screen resolution,  FIG. 4  is a schematic diagram illustrating a screen  102  displayed in the display unit  10  shown in  FIG. 1  in another screen resolution, and  FIG. 5  is a flowchart illustrating an image display method according to an embodiment of the invention. The image display method shown in  FIG. 5  is adapted to the display device  1  shown in  FIG. 1 . 
         [0025]    As shown in  FIG. 1 , the display device  1  comprises a display unit  10 , a storage unit  12 , a processing unit  14  and an image generating unit  16 , wherein the processing unit  14  is electrically connected to the display unit  10  and the storage unit  12 , and the image generating unit  16  is electrically connected to the display unit  10  and the processing unit  14 . In this embodiment, the display device  1  may be an electronic device with display function, such as a computer screen, a television, a monitor, etc.; the display unit  10  may be a liquid crystal display device, a plasma display device or other display devices; the storage unit  12  may be a hard disc, a memory, a memory card or other data storage devices; the processing unit  14  may be a processor or controller with data processing function; and the image generating unit  16  may be an on screen display (OSD) generator or other image generators. In general, the display device  1  may be further equipped with some necessary hardware or software components for specific purposes, such as a power supply, a circuit board, applications, an antenna, an input/output module, a communication module, etc., and it depends on practical applications. 
         [0026]    In this embodiment, the display unit  10  may have N adjustable screen resolutions, wherein N is a positive integer larger than 1. For example, if the display unit  10  has three adjustable screen resolutions including 1600*900, 1440*900 and 1366*768, N is equal to 3 accordingly. It should be noted that the number and scale of the adjustable screen resolutions of the display unit  10  are not limited to the aforesaid embodiment and depend on practical applications. 
         [0027]    In this embodiment, the storage unit  12  stores a setting list  120  and the setting list  120  records the N adjustable screen resolutions and N display ratio parameters, wherein each of the N adjustable screen resolutions is corresponding to one of the N display ratio parameters. Preferably, each of the N display ratio parameters comprises a horizontal pixel amount per unit length and a vertical pixel amount per unit length, wherein the horizontal pixel amount per unit length represents that a ratio of pixel amount to real display length along a horizontal direction of the display unit  10 , and the vertical pixel amount per unit length represents that a ratio of pixel amount to real display length along a vertical direction of the display unit  10 . As shown in  FIG. 2 , the setting list  120  records three display ratio parameters  122  corresponding to the three adjustable screen resolutions 1600*900, 1440*900 and 1366*768, wherein the horizontal pixel amount per unit length is represented by HorzPixelsPerMm and the vertical pixel amount per unit length is represented by VertPixelsPerMm. 
         [0028]    For example, the invention may calculate the horizontal pixel amount per unit length HorzPixelsPerMm and the vertical pixel amount per unit length VertPixelsPerMm corresponding to each of the adjustable screen resolutions according to the following steps. First of all, the invention displays a rectangle with known pixel amount in the display unit  10 , such as a rectangle with 500*500 pixels. Afterward, the invention uses a straightedge to measure a real display size of the rectangle. For example, the measurement result may be 135.4 mm*131.5 mm. Finally, the invention will obtain that HorzPixelsPerMm=500/135.4=3.69276 and VertPixelsPerMm=500/131.5=3.80228. 
         [0029]    For another example, the invention may also calculate the horizontal pixel amount per unit length HorzPixelsPerMm and the vertical pixel amount per unit length VertPixelsPerMm corresponding to each of the adjustable screen resolutions according to the following steps. First of all, the invention may draw a rectangle with a size of 100 mm*100 mm on a transparent sheet and then attach the transparent sheet onto a center of the display unit  10 . Afterward, the invention may execute a program allowing a user to operate a mouse to select four corners of the rectangle and then the program will calculate the pixel amount corresponding to the rectangle. For example, the calculation result may be 300*320 pixels. Finally, the invention will obtain that HorzPixelsPerMm=300/100=3 and VertPixelsPerMm=320/100=3.2. 
         [0030]    It should be noted that the manner for calculating the horizontal pixel amount per unit length HorzPixelsPerMm and the vertical pixel amount per unit length VertPixelsPerMm can be determined according to practical applications, so the invention is not limited to the aforesaid embodiments. 
         [0031]    As shown in  FIGS. 3 and 4 , the display unit  10  displays screens  100  and  102  in different screen resolutions, wherein the screen resolution of the screen  100  is lower than the screen resolution of the screen  102 . When a user is going to show an image  104  in the display unit  10 , the invention will display the image  104  with a fixed size in the display unit  10  according to a current screen resolution of the display unit  10  and the setting list  120 , so as to prevent the image  104  from enlarging or reducing due to different screen resolutions. In this embodiment, when the image  104  is displayed in the display unit  10 , the image  104  has a fixed horizontal length HL and a fixed vertical length VL no matter what the scale of the current screen resolution is. 
         [0032]    Accordingly, the invention has to provide a setting list  120  (step S 10  in  FIG. 5 ) in advance, such that the image  104  can be displayed in the display unit  10  in different screen resolutions by a fixed size. Afterward, when a user is going to show the image  104  in the display unit  10 , the processing unit  14  will retrieve a current screen resolution from the display unit  10  (step S 12  in  FIG. 5 ) and compares the current screen resolution with the N adjustable screen resolutions of the setting list  120  (step S 14  in  FIG. 5 ). Then, the processing unit  14  selects an i-th display ratio parameter  122  corresponding to an i-th adjustable screen resolution of the N adjustable screen resolutions from the N display ratio parameters of the setting list  120  when the current screen resolution is identical to the i-th adjustable screen resolution (step S 16  in  FIG. 5 ), wherein i is a positive integer smaller than or equal to N. Finally, the image generating unit  16  generates an image  104  according to the i-th display ratio parameter  122  (step S 18  in  FIG. 5 ) and displays the image  104  in the display unit  10  (step S 20  in  FIG. 5 ). In step S 18  of  FIG. 5 , the image generating unit  16  may multiply the fixed horizontal length HL of the image  104  by the horizontal pixel amount per unit length HorzPixelsPerMm of the i-th display ratio parameter  122  and multiply the fixed vertical length VL of the image  104  by the vertical pixel amount per unit length VertPixelsPerMm of the i-th display ratio parameter  122 , so as to generate the image  104 . 
         [0033]    For example, if the current screen resolution of the screen  100  shown in  FIG. 3  is 1366*768, the image generating unit  16  may multiply the fixed horizontal length HL of the image  104  by the horizontal pixel amount per unit length HorzPixelsPerMm of the third display ratio parameter  122  of the setting list  120  (i.e. HL*3.190000) and multiply the fixed vertical length VL of the image  104  by the vertical pixel amount per unit length VertPixelsPerMm of the third display ratio parameter  122  of the setting list  120  (i.e. VL*3.300000), so as to generate the image  104 . Accordingly, the invention can obtain the horizontal pixel amount (i.e. HL*HorzPixelsPerMm) and the vertical pixel amount (i.e. VL*VertPixelsPerMm), which are covered by the fixed horizontal length HL and the fixed vertical length VL of the image  104  in the current screen resolution 1366*768. 
         [0034]    For example, if the current screen resolution of the screen  102  shown in  FIG. 4  is 1600*900, the image generating unit  16  may multiply the fixed horizontal length HL of the image  104  by the horizontal pixel amount per unit length HorzPixelsPerMm of the first display ratio parameter  122  of the setting list  120  (i.e. HL*3.720000) and multiply the fixed vertical length VL of the image  104  by the vertical pixel amount per unit length VertPixelsPerMm of the first display ratio parameter  122  of the setting list  120  (i.e. VL*3.850000), so as to generate the image  104 . Accordingly, the invention can obtain the horizontal pixel amount (i.e. HL*HorzPixelsPerMm) and the vertical pixel amount (i.e. VL*VertPixelsPerMm), which are covered by the fixed horizontal length HL and the fixed vertical length VL of the image  104  in the current screen resolution 1600*900. 
         [0035]    Accordingly, the invention can display the image  104  with a fixed size in the display unit  10  in different screen resolutions, so as to prevent the image  104  from enlarging or reducing due to different screen resolutions. 
         [0036]    Furthermore, as shown in  FIGS. 3 and 4 , when the image  104  is displayed in the display unit  10 , a horizontal distance HD is between a reference point P of the image  104  and a first edge E 1  of the display unit  10  and a vertical distance VD is between the reference point P of the image  104  and a second edge E 2  of the display unit  10 , wherein the first edge E 1  is perpendicular to the second edge E 2 . In step S 18  of  FIG. 5 , the image generating unit  16  may multiply the horizontal distance HD by the horizontal pixel amount per unit length HorzPixelsPerMm of the i-th display ratio parameter  122  and multiply the vertical distance VD by the vertical pixel amount per unit length VertPixelsPerMm of the i-th display ratio parameter  122 , so as to display the image  104  at a fixed position in the display unit  10  according to the reference point P. 
         [0037]    For example, if the current screen resolution of the screen  100  shown in  FIG. 3  is 1366*768, the image generating unit  16  may multiply the horizontal distance HD by the horizontal pixel amount per unit length HorzPixelsPerMm of the third display ratio parameter  122  of the setting list  120  (i.e. HD*3.190000) and multiply the vertical distance VD by the vertical pixel amount per unit length VertPixelsPerMm of the third display ratio parameter  122  of the setting list  120  (i.e. VD*3.300000), so as to generate the image  104 . Accordingly, the invention can obtain the horizontal pixel amount (i.e. HD*HorzPixelsPerMm) and the vertical pixel amount (i.e. VD*VertPixelsPerMm), which are covered by the horizontal distance HD and the vertical distance VD in the current screen resolution 1366*768. 
         [0038]    For example, if the current screen resolution of the screen  102  shown in  FIG. 4  is 1600*900, the image generating unit  16  may multiply the horizontal distance HD by the horizontal pixel amount per unit length HorzPixelsPerMm of the first display ratio parameter  122  of the setting list  120  (i.e. HD*3.720000) and multiply the vertical distance VD by the vertical pixel amount per unit length VertPixelsPerMm of the first display ratio parameter  122  of the setting list  120  (i.e. VD*3.850000), so as to generate the image  104 . Accordingly, the invention can obtain the horizontal pixel amount (i.e. HD*HorzPixelsPerMm) and the vertical pixel amount (i.e. VD*VertPixelsPerMm), which are covered by the horizontal distance HD and the vertical distance VD in the current screen resolution 1600*900. 
         [0039]    Accordingly, the invention can display the image  104  with a fixed size at a fixed position in the display unit  10  in different screen resolutions, so as to prevent the image  104  from shifting due to different screen resolutions. 
         [0040]    Still further, the display device  1  may further comprise a button  18  disposed at a periphery of the display unit  10 . The user can press the button  18  to show the image  104 . As shown in  FIGS. 3 and 4 , the fixed position of the image  104  is corresponding to the button  18 . In other words, the invention can display the image  104  at the fixed position corresponding to the button no matter what the scale of the current screen resolution is, so as to prevent the image  104  from shifting due to different screen resolutions. 
         [0041]    Referring to  FIG. 6 ,  FIG. 6  is a schematic diagram illustrating a setting interface  106  displayed in the display unit  10  shown in  FIG. 1 . As shown in  FIG. 6 , the invention may display a setting interface  106  in the display unit  10 , wherein the setting interface  106  is used for setting the fixed horizontal length HL and the fixed vertical length VL of the image  104 . Accordingly, the user can set the fixed horizontal length HL and the fixed vertical length VL of the image  104  in the setting interface  106  according to his/her preference. 
         [0042]    As mentioned in the above, the invention makes the setting list in advance according to a plurality of adjustable screen resolutions of the display unit and then stores the setting list in the storage unit of the display device. When a user is going to show an OSD image or other images in the display unit, the invention will calculate the horizontal pixel amount and the vertical pixel amount, which are covered by the fixed horizontal length and the fixed vertical length of the image, according to the current screen resolution of the display unit and the setting list. Accordingly, the invention can display the image with a fixed size in the display unit in different screen resolutions, so as to prevent the image from enlarging or reducing due to different screen resolutions. Furthermore, the invention may set the reference point on the image and then calculates the horizontal pixel amount and the vertical pixel amount, which are covered by the horizontal distance and the vertical distance between the reference point of the image and the edges of the display unit, according to the current screen resolution of the display unit and the setting list. Accordingly, the invention can display the image with a fixed size at a fixed position in the display unit in different screen resolutions. The aforesaid fixed position may be corresponding to the button disposed at the periphery of the display unit, so as to prevent the image from shifting due to different screen resolutions. Moreover, the invention may display the setting interface, which is used for setting the fixed horizontal length and the fixed vertical length of the image, in the display unit. Accordingly, the user can modify the fixed horizontal length and the fixed vertical length of the image displayed in the display unit through the setting interface according to his/her preference. Since the invention displays the image with the fixed size in different screen resolutions through software without the scaler or other hardware of the prior art, the invention can further reduce the manufacturing cost. 
         [0043]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method 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.