Abstract:
A visual display system is described that optimizes the apparent visual effect of a particular sequence of screen update process. The system includes at least one input device and a display unit. The input device operates to receive instructions from the operator. The display unit has some screen setup at any instant in time. The display unit is capable of modifying the screen setup in response to the instructions from the input device at a particular rate. The modification is made in such a sequence of updates that it gives visual impressions of the updates running at a higher rate than the particular rate.

Description:
TECHNICAL FIELD 
     The present specification generally relates to portable electronic devices, and particularly, to a video display update system in a electronic device that changes refresh directions. 
     BACKGROUND 
     Many portable electronic devices, such as portable communication devices, cellular and cordless telephones, pagers and the like, include miniature visual display screens that display graphical or text data. Often, it is desirable to allow the operator to control and modify the screen setup of the display. 
     However, existing portable devices are often controlled by relatively slow processors. These can refresh the displays at a relatively slow rate. The slow refresh rate can cause the display to show, temporarily, both the old display items and the new display items. For example, when the operator moves the cursor up to highlight a new controlled area, both the new area and the old area are often highlighted. This effect aggravates the operator&#39;s visual perception of the sluggishness of the display. 
     SUMMARY 
     The techniques described herein obviate this problem by controlling the processor to update the visual display in different directions. By optimizing the apparent visual effect of a particular sequence of the screen update process, the operator&#39;s impression of sluggishness can be obviated without actually increasing the update rate. 
     In one aspect, the present disclosure involves a visual display system. The system includes at least one input device and a display unit. The input device operates to receive instructions from the operator. The display unit allows some screen setup at a first time. The display unit is capable of modifying the screen setup in response to the instructions from the input device at a particular rate. The direction of updates gives visual impressions of updates running at a higher rate than the particular rate. 
     The instruction received by the input device can be to scroll the cursor in a first direction. The screen is updated from bottom to top when the instruction is to scroll the cursor down. The screen is updated from top to bottom when the instruction is to scroll the cursor up. 
     In another aspect, a method for updating a screen setup in a visual display is disclosed. The method includes receiving instructions and modifying the screen setup in response to the received instructions at a particular rate. The modification is made in a sequence of updates that gives visual impressions of the updates running at a higher rate than the particular rate. 
     In some embodiments, the method also includes updating the screen setup from bottom to top if the instruction is to scroll up, and from top to bottom if the instruction is to scroll down. 
     In another aspect, a portable communication device, such as a cellular telephone system, is disclosed. The communication device includes at least one input device, a display unit, and communication electronics. 
     The communication electronics operate to establish a communication link with remote users. The communication electronics are configured to interface with the at least one input device and the display unit is configured to communicate the received instructions, among other information, to the remote users. The communication electronics update the display unit with information about the communication link. 
     In a further aspect, a portable video game is disclosed. The video game includes at least one input device and a display unit. In one embodiment, the instruction received by the input device is to move the screen setup in a particular direction. The sequence of updates for the screen setup starts from an area near the particular direction indicated by the input device. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other embodiments and advantages will become apparent from the following description and drawings, and from the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other aspects will be described in reference to the accompanying drawings wherein: 
     FIG. 1 is an illustration of screen scrolling processes for an ideal visual display; 
     FIG. 2 is a scroll-up process for a visual display system using a conventional top-to-bottom refresh technique; 
     FIG. 3 is an improved scrolling process for a visual display system using a bi-directional refresh technique; 
     FIG. 4 is a block diagram of the visual display system; 
     FIG. 5 is a flow diagram of the bi-directional refresh process; 
     FIG. 6A is a front perspective view of a cellular telephone system using the visual display system; 
     FIG. 6B is a block diagram of the cellular telephone system shown in FIG. 6A; 
     FIG. 7 is a front view of a portable communication device; 
     FIG. 8 is a front view of a portable pager system; and 
     FIG. 9 is a front view of a portable video game using the visual display system. 
    
    
     Like reference numbers and designations in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     A detailed description of a preferred embodiment of a bi-directional display update technique is herein provided with respect to the figures. 
     FIG. 1 illustrates scrolling processes for an ideal visual display. A display screen  100 , shown at the top, highlights a controlled area designated as ‘Phone Book’  102 . Another display screen  110 , shown at the bottom, highlights another controlled area designated as ‘Messages’  112 . 
     When the operator scrolls the cursor up, the visual display changes from the top screen  100  to the bottom screen  110 . The highlighted controlled area is commanded to change from the ‘Phone Book’ area  102  to the ‘Messages’ area  112 . On the other hand, when the operator scrolls the cursor down, the visual display changes from the bottom screen  110  to the top screen  100 . The highlighted controlled area is commanded to change from the ‘Messages’ area  112  to the ‘Phone Book’ area  102 . 
     FIG. 2 shows a scroll-up process for a conventional visual display system using a top-to-bottom refresh technique. The top display  200  shows the initial screen with the ‘Phone Book’ controlled area  208  highlighted. 
     When the operator scrolls the cursor up, the refresh software updates the screen, line at a time, from top to bottom. The middle screen  202  shows the intermediate state displayed by the refresh software when the refresh operation has reached the point  207 . The middle screen  202  shows the ‘Messages’ controlled area  206  being updated first with the new ‘Messages’ area  206  highlighted. However, the ‘Phone Book’ area  208  is not updated yet and hence the old ‘Phone Book’ area  208  is still displayed as highlighted. When the ‘Phone Book’ controlled area  208  is updated, the area  208  is inverted and no longer highlighted. The bottom screen  204  shows this final state of the visual display. 
     In a slow processor, the middle screen  202  may persist in the intermediate state for a long period of time before updating the rest of the screen. Therefore, the screen  202  shows a cursor shadow in the ‘Phone Book’ area  208 . This gives the user the impression that the display system is slow. 
     FIG. 3 shows an improved scrolling process for a visual display system with a bi-directional refresh technique. The technique optimizes the apparent visual effect of a particular sequence of the cursor scrolling process without actually increasing the update rate. 
     The top screen  300  and the bottom screen  304  are the same as in FIG.  2 . However, the middle screen  302  displays an intermediate state that optimizes the apparent visual effect. 
     When the cursor is scrolled up, the screen sequence goes from the top screen  300  to the bottom screen  304 . In this case, the refresh software is commanded to update the screen from the bottom up. Therefore, the ‘Phone Book’ controlled area  308  is updated first and the previously highlighted area is inverted. The middle screen  302 , in FIG. 3, no longer displays the unwanted cursor shadow. 
     When the cursor is scrolled down, the screen sequence is from the bottom screen  304  to the top screen  300 . In this case, the refresh software is commanded to update from the top down. Therefore, the ‘Messages’ controlled area  306  is updated first and the previously highlighted area is inverted. The middle screen  302  again eliminates the unwanted cursor shadow. 
     FIG. 4 shows a block diagram of the visual display system  400 . The display system  400  includes a processor  402 , an input device  404 , a graphical interface unit  406 , and a video display unit  408 . 
     The processor  402  monitors operator input from the input device  404 . Based on the direction of the input, the processor  402  informs the graphical interface unit  406  about the refresh direction of the video display  408  screen. The graphical interface unit  406  updates the video display unit  408  screen using the refresh data stored in the video memory  410 . The graphical interface unit  406  recalls the refresh data from the top or the bottom of the video memory  410  according to the direction given by the processor  402 . 
     In some embodiments, the input device  404  may be a keypad, push-button switches, or some combination of switches, buttons, and joysticks. The video display unit  408  may be a liquid-crystal display (LCD) or a cathode-ray tube (CRT) display. 
     FIG. 5 shows a flow diagram of the bi-directional refresh process. The process may be a computer-implemented method or a computer program residing on a computer-readable medium in the visual display system  400 . 
     The refresh process starts when the processor  402  detects a cursor movement through the input device  404  at step  500 . The processor  402  then determines the direction of the cursor at step  502 . If the cursor direction is down, the processor  402  commands the graphical interface unit  406  to update the video display  408  from top to bottom at step  504 . If the cursor direction is up, the processor  402  commands the graphical interface unit  406  to update the video display  408  from bottom to top at step  506 . 
     The video display screen is updated at step  508  according to the cursor direction determined in step  502 . Finally, the processor polls the input device  404  at step  510  to determine if the display system is still on. If so, the input device  404  is again polled for cursor movement. Otherwise, the process is exited. 
     FIG. 6A shows a front perspective view of a cellular telephone system  600  using the visual display system  400 . The cellular telephone system  600  also includes a key pad  602  and various other buttons  610  that are part of the input devices in the display system  400 . The telephone system  600  also includes a speaker  604 , a microphone  608 , an antenna  606 , and other communication electronics  614  contained within the telephone housing  612 . 
     FIG. 6B shows a block diagram of the cellular telephone system  600  including the communication electronics  614 . 
     FIG. 7 shows a portable communication device  700  including the visual display system  400 . The communication device  700  also includes communication electronics similar to those in the cellular telephone system  600 . 
     FIG. 8 shows a portable pager system  800  including the visual display system  400 . The pager system  800  can use up-down buttons  802  as input devices. The pager system  800  also includes communication electronics. 
     FIG. 9 shows a portable video game  900  including the visual display system  400 . The video game  900  can use push-buttons  902  and joystick buttons  904  as input devices. 
     The display screen in the video game  900  is updated according to the direction of the input device. For example, if the input device indicates a movement to the right, an area near the right portion of the display screen is updated first, and so on. 
     Although only a few embodiments have been described in detail above, those of ordinary skill in the art certainly understand that modifications are possible. For example, the bi-directional display update technique is flexible enough to update different controlled area from side to side instead from top to bottom or from bottom to top. In addition, the refresh technique may include other more complex update scheme involving graphical data patterns. 
     All such modifications are intended to be encompassed within the following claims, in which: