Patent Publication Number: US-2010117956-A1

Title: Display system and method for controlling an on-screen display within a display screen

Description:
This application claims the benefits of the Taiwan Patent Application Serial NO. 097143475, filed on Nov. 11, 2008, the subject matter of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a display system and method for controlling an on-screen display within a display screen, more particularly to a display system which controls an on-screen display within a display screen and which uses lesser memory device for accomplishing the task. 
     2. Description of the Prior Art 
     A display screen is the best Human Media Interaction. When the display screen is in use, it is often required to adjust its brightness, viewing options, channels, color contrast, screen dimension and horizontal or vertical position of the screen display in order to provide the outmost viewing ability. Generally speaking, the aforesaid features of the display screen are default during the mass production. After sale of the display screen (or the display device), in case the end user wishes to adjust these features, then the on-screen display within the display screen is applied. 
     The on-screen display will appear in the display screen upon switch-on operation and an input device (such as a remote control) is applied to adjust the parameters of the on-screen display so as to set the background and features of the screen display in the display screen. 
     A conventional display system with OSD ability requires a relatively large hardware, such as ROM (Read Only Memory) and RAM (Random Access Memory). The on-screen display usually consists of a text information and an Icon. The text information includes a display column consisting of a plurality of literal strings or bar charts. Each literal string is formed by combining several numbers of letters. In each literal string, some letters may be repeatedly used in addition to its color, font and etc. . . . According to the prior art, all of the literal strings are fully stored within the memory device (usually in ROM) and they will be downloaded within the RAM upon initialization of the display system. 
     It takes tremendously large memory device so that the cost of the hardware structure is high and the response speed is slow and is therefore not beneficial f or the market competition. For instance, an X-ray film for medical display should have high resolution in order to assist in finding out the disease. If the text information in the screen display is needed to be enlarged, it requires tremendously large memory source according to the prior art technology. 
     In addition, in case the display is required to be rotated, the text information (or the X-ray film) in the display screen also rotates simultaneously with the display screen. Generally, the display screen is rotated 90° from its initial position. In order to complement with and provide accurate two dimensional rotation of the display screen, the apparatus requires twice of its initial storage space, thereby wasting a great deal of memory device and causing a burden for the processor. Thus, the hardware device of the X-ray apparatus needs to be increased to comply with the added memory, which is against the economic trend for the manufacturers. 
     Therefore, the main object of the present invention is to provide a display system and the method thereof, where, a relatively large memory device can be economized and which includes icon and control settings that can be independently and simultaneously controlled so as to overcome the drawbacks encountered during use of the prior art display system. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a display system and the method thereof, where, a relatively large memory device can be economized and which includes icon and control settings that can be independently and simultaneously controlled so as to economize the expense of the hardware and lowers the processing load of the processor, thereby quickening the operation speed of the processor. In practical, the load of ROM and RAM is reduced apparently. 
     A display system of the present invention is used for controlling an on-screen display within a display screen of a display device. The on-screen display is a screen data in the form of a text information including a display column consisting of a literal string formed by combining several numbers of letters. 
     The display system accordingly includes a memory device, a controller and a text buffer. 
     Upon initialization of the display device, the controller downloads and temporarily stores a coding chart that includes a group of string-forming codes and a group of letter-forming codes. The coding chart further includes different groups of string-forming codes for encoding different types of the literal strings. The string-forming codes and the letter-forming codes are corresponding to the several pieces of letter information in the memory device. 
     Upon receipt of an external command corresponding to a specific string-forming code, the controller fetches a respective letter-forming code from the coding chart based on the specific string-forming code and a respective piece of letter information from the memory based on the respective letter-forming code, thereby encoding the literal string and displaying the literal string over the display screen. 
     The text buffer is used for temporarily storing the literal strings. The letter parameters for setting feature of a letter are also stored in the text buffer. An output buffer is used for temporarily storing the icon from the memory device and the text information from the text buffer, and thus an assembly of the icon and the text information is displayed over the display screen  31 . 
     In the display system and method of the present invention, the memory device is stored with several pieces of letter information. The coding chart can be downloaded with the assistance of the controller for encoding the literal string by fetching the string-forming codes and the letter-forming codes from the coding chart, thereby economizing the expense of the hardware and lowers the processing load of the processor, which, in turn, quickens the operation speed of the processor. In practical, the load of ROM and RAM is reduced apparently. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiment of this invention, with reference to the accompanying drawings, in which: 
         FIG. 1A  illustrates a display screen of a display system according to the present invention, wherein the display screen shows a screen display including a literal string; 
         FIG. 1B  illustrates a display screen of the display system according to the present invention, wherein the display screen shows a screen display including a bar chart; 
         FIG. 2  shows functions of the display system of the present invention; 
         FIG. 3  illustrates how an on-screen display in the screen display is controlled to change its position and orientation with respect to the display screen of the display system of the present invention; and 
         FIG. 4  shows a block diagram illustrating the steps in the display method of the present invention to be applied in a display system for controlling an on-screen display in a display screen. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1A  illustrates a display screen  31  of a display system according to the present invention, wherein the display screen  31  shows a screen display including a literal string  4204   a .  FIG. 1B  illustrates the display screen  31  of the display system according to the present invention, wherein the display screen  31  shows a screen display including a bar chart  4204   b . The screen display includes a screen data  42  having an upper section formed with a plurality of icons  4202 , a middle section with a text information  4204  generated due to clicking a respective icon  4202  and a lower section formed with a trade logo  4206 . 
     The icons  4202  can be optionally selected and upon clicking a respective icon  4202  and a corresponding text information  4204  will appear below it. In  FIG. 1A , the text information includes a display column consisting of five rows  22  of information. Each row  22  is a literal string  4204   a , as shown in  FIG. 1A  or a bar chart  4204   b , as shown in  FIG. 1B . 
     In case the text information  4204  includes the literal strings  4204   a , where each literal string  4204   a  is formed by combing several numbers of letters  24 . As best shown in  FIG. 1A , the first literal string  4204   a  is [GAMMA] formed by combining five letters  24 , the second literal string  4204   a  is [DICOM] formed by combining five letters  24  and respectively occupying the second and third rows  22  while the fourth and fifth rows  22  remain blank. 
     The text information  4204  may include the bar chart  4204   b  in addition to the literal string  4204   a , as shown in  FIG. 1B , where the first literal string  4204   a  is [RED] formed by combing three letters  24  and is occupying the first row  22 . The second literal string  4204   a  is [128] formed by combining three letters  24  and is occupying the fourth row  22 . The third row  22  shows a bar chart  4204   b  while the second and fifth rows  22  remain blank. 
     The trade logo  4206  in fact is a are drawing, and therefore has no function ability. The screen data  42  of the screen display further has a few function keys  12  to permit the user to operate. 
       FIG. 2  shows functions of the display system  30  of the present invention. The display system  30  of the present invention is used for controlling the on-screen display (the screen data  42 ) within the display screen  31 . As shown in  FIGS. 1A and 1B , the text information  4204  of the screen data  42  includes five rows  22 , each row showing a literal string  4204   a  or a bar chart  4204   b , wherein the literal string  4204   a  is formed by combining several numbers of letters  24 . 
     The text information  4202  will be described first while the icons  4202  and the control setting  80  will be deal with later. The display system  30  of the present invention further includes a memory device  32 , a controller  34  and a text buffer  36 . 
     The memory device  32  is used for storing several pieces of letter information  32 A. The memory device  32  uses black and white levels for recording the several pieces of letter information  32 A. The memory device  32  further includes a ROM (read-only memory)  3202  for permanently storing the several pieces of letter information  32 A and a RAM (random access memory)  3204  for temporarily storing the several pieces of letter information  32 A downloaded from the ROM  3202  during initialization of the display system  30 . 
     The controller  34  includes a register  3402  for downloading and temporarily storing a coding chart  50  upon initialization of the display system  30 . The coding chart  50  includes a group of string-forming codes  52  and a group of letter-forming codes  54 . The coding chart  50  further includes different groups of string-forming codes  52  for encoding different types of the literal strings  4204   a . The string-forming codes  52  and the letter-forming codes  54  are correspond to the several pieces of letter information  32 A. 
     Upon receipt of an external command corresponding to a specific string-forming code  52 , the external command is transferred to the processor  38  via a flexible cable or an interface. Note that, the display device may include a software device for conducting the fetching and transferring of the control setting to the controller  34  via the flexible cable or the interface. 
     At this time, the controller  34  fetches a respective letter-forming code  54  from the coding chart  50  based on the specific string-forming code  52  and a respective piece of letter information  32 A from the memory device  32  based on the respective letter-forming code  54 , thereby encoding the literal string  4204   a  and displaying the literal string  4202   a  over the display screen. The literal string  4204   a  may consist of several identical letters  24  (i.e. a single letter is repeatedly used). Since the memory device  32  is stored with only one piece for each of the several pieces of letter information, a relatively large amount of storage space is reduced in the memory device  32 . 
     In real application, the memory circuit in the built-in chipset serves as the text buffer  36  for quickly and temporarily storing the literal strings  4204   a  for future use and the literal strings  4204   a  are displayed over the display screen  31 . 
     The display screen  31  further includes a ROM (read-only memory)  37  and a MCU (microprocessor)  38 . In this embodiment, EPROM  3202  (Erasable Programmable Read-Only Memory) or EEPROM  3202  (Electrically Erasable Programmable Read-Only Memory) is used for the ROM (read-only memory)  37 , in which, the control setting  80  and the coding chart  50  are stored in advance. 
     During the initialization of the display screen  31 , the processor  38  will download the control setting  80  and the coding chart  50  from the ROM  37  and transfer the same to the controller  34 . 
     The control setting  80  is used for setting display modes of the screen data  42  (the on-screen display). The control setting  80  further includes background parameters  80   b  for setting a background feature of the screen display in the display screen  31  and letter parameters  80   a  for setting feature of a letter. The background parameters  80   b  include the image position relative to its background, distance or dimension of the background relative to the image, brightness or color of the background settings of the OSD (on-screen display). The letter parameters  80   a  include colors of the letters, fonts, style and size of the letters. 
     Regarding to the colors, the memory device  32  uses black and white levels for recording the several pieces of letter information  32 A. The letter parameters for setting feature of the letter include color information. The controller  34  downloads the color information from letter parameters  80   a  of control setting  80  for substituting the black and white levels in order to control the display modes of the screen data  42 . Since the black and white levels respectively need single 1-bit memory for recording while each of the RBG (Red, Blue and Green) respectively need 24 bits, a relatively large memory space can be economized, which, in turn, lowers the load of the memory device  32 . 
     The screen data  42  further includes, in addition to the text information  4204 , at least one icon  4202  stored in the memory device  32 . To be more specific, the icon  4202  is stored in the ROM  3202  like the several pieces of letter information  32 A. The coding chart  50  further has a group of icon-forming codes  56 , one of which corresponds to the icon  4202 . Upon initialization of the display system  30 , the icon  4202  is downloaded and stored within the RAM (random access memory)  3204 . 
     Upon receipt of the external command, the controller  34  searches and fetches a respective icon-forming code  56  from the coding chart  50  based on the icon  4202 . An output buffer  92  is used for temporarily storing the icon  4202  which is combined with the text information  4204  later, thereby displaying the screen data  42  over the display screen  31 , 
     The several pieces of letter information  32 A stored within the memory device  32  in reality include letters or characters of multiple languages. However, for the sake of practical application, only those letters to be used in the screen data  42  are stored within the memory device  32  so as to reduce the burden and thus quicken the operation speed of the processor. 
     The display system  30  of the present invention further includes a template generator  90  and an output buffer  92  in addition to the text buffer  36 . 
     The template generator  90  is used for generating a template for serving as the background feature of the screen display based on the background parameters  80   b.    
     The output buffer  92  is used for temporarily storing the icon  4202  from the memory device  32 , the text information  4204  from the text buffer  36 , the template from the template generator  90  and thus an assembly of the icon  4202 , the text information  4204  and the template is displayed over the display screen  31 . 
     Note that in the present invention, the control setting  80  and the coding chart  50  can be simultaneously downloaded during the initialization of the display system  30  or the former two are downloaded separately after the initialization of the display system  30 . 
     For instance, in case the control setting  80  are downloaded separately after the initialization of the display system  30 , the user can click a respective function in the menu or he can click a respective icon  4202  in order to display a corresponding text information  4204 . Regarding the coding chart  50 , the same can be either fully or partially downloaded and is temporarily stored in the register  3402  after the initialization of the display system  30  so as to economize the hardware and thus increase the function ability of the display system  30 . 
       FIG. 3  illustrates how the control setting  80  is applied to control the screen data  42  in the screen display  31  to change its position and orientation with respect to the display screen of the display system  30  of the present invention. 
     Sometimes, the display screen  31  applied in the medical field is required to change from its initial position to a predetermined position. Under such condition, the control setting  80  further includes position-setting parameters  82  and orientation-setting parameters  83  cooperating with the position-setting parameters  82  for determining display modes so as to define a position and orientation of the screen data  42  in the display screen  31  when the latter is rotated to the predetermined position. 
     In real application, the position-setting parameters  82  and orientation-setting parameters  83  of the screen display in the display screen  31  can be selected by menu of OSD externally. Under this condition, the display system  30  of the present invention further includes a press button  90  and a touch button  92 . The press button  90  corresponds to the orientation-setting parameters  83  and depression of which results in rotation of the screen data  42  relative to the display screen  31 , thereby changing the orientation of the screen data  42 . 
     In addition, rotation of the display screen  31  from its initial position to the predetermined position will be activated by the touch button  92 , such as by means of magnetic reed or switches, thereby retaining the screen data  42  at the upper left corner of the display screen  31 , as shown in  FIG. 3 . 
       FIG. 4  shows a block diagram illustrating the steps in the display method of the present invention to be applied in the display system  30  for controlling the on-screen display (the screen data  42 ) in the display screen  31 . The screen data  42  is in the form of the text information  4204  includes a display column  22  consisting of the literal string  4204   a  formed by combining several numbers of letters  24 . The method accordingly includes the following steps. 
     According to the step S 02 , upon initialization of the display device, a coding chart  50  is downloaded and temporarily stored, wherein the coding chart  50  includes a group of string-forming codes  52  and a group of letter-forming codes  54  corresponding to the several pieces of letter information  32 A. The coding chart  50  further includes a group of icon-forming codes  56 . 
     The coding chart  50  has different groups of string-forming codes  52  for encoding different types of the literal strings  4204   a.    
     At the same time, the control setting  80  is downloaded together with the coding chart  50  during the initialization of the display device. The control setting  80  is used for setting display modes of the screen data  42 , wherein the control setting  80  includes parameters for setting the feature of the screen display in the display screen  31 . In addition, the several pieces of letter information  32 A in fact are black and white levels. The control setting  80  may include color information, which is downloaded for substituting the black and white levels in order to control the display modes of the screen data  42 . 
     According to the step S 04 , an external command corresponding to a specific string-forming code  52  is received. 
     A respective letter-forming code  54  is fetched from the coding chart  50  based on the specific string-forming code  52 , according to the step S 06 . 
     According to step S 08 , a respective piece of letter information  32 A is fetched from the memory device  32  based on the respective letter-forming code  54  for encoding the literal string  4204   a.    
     The literal string  4204   a  is stored temporarily, according to the step S 10 , 
     According to the step S 12 , the literal string  4204   a  is displayed over the display screen  31 . 
     In addition, upon receipt of the external command, a respective icon-forming code  56  is searched and fetched from the coding chart  50  based on the icon  4202 , thereby encoding the literal string  4204   a  and displaying the literal string  4204   a  over the display screen  31 . The text information  4204  is corresponding to the icon  4202 . 
     Note that the display screen  31  applied in the medical field is required to change from its initial position to a predetermined position for a medical practitioner to diagnose the disease (for example, viewing an X-ray film). The orientation of the text information is required to be rotated from its initial position. Under such condition, the control setting  80  includes position-setting parameters  82  and orientation-setting parameters  83  cooperating with the position-setting parameters  82  for determining display modes so as to define a position and orientation of the screen data  42  in the display screen  31  when the latter is rotated to the predetermined position. 
     As explained above, in the display method of the present invention, the several pieces of letter information  32 A are stored in the memory device  32 . The controller  34  fetches the string-forming codes  52  and the letter-forming codes  54  from the coding chart  50  in order to encode the literal string  4204   a . Therefore, a relatively large memory device can be economized and consequently lowers the processing load of the processor, thereby quickening the operation speed of the processor. In real application, the storage space or load of the ROM  3202  and the RAM  3204  is directly reduced. 
     While the invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.