JP2009093374A - Client device and server device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a client device and a server device for displaying drawing data generated and transferred by a server device so as to be displayed by a client device with excellent responsiveness. <P>SOLUTION: The height Hv of a virtual screen area 10B is set so as to be higher than the height Hd of a screen display area 26A, and an upward scroll time boundary 20u and a downward scroll time boundary 20d are set from the both upper and lower ends of the virtual screen area 10B to the front part of set width, and in the upward scroll operation, the scroll request of the virtual screen area 10B is transmitted to a server device 10 only when the upper end of a screen display area 26A reaches the upper scroll time boundary 20u, and in the downward scroll operation, the scroll request of the virtual screen area 10B is transmitted only when the lower end of the screen display area 26A reaches a downward scroll time boundary 20D. The scroll width Ss of the virtual screen area 10B accompanied by one scroll request to the server device 10 is set to N times or more (Ss≥N×Sd) with respect to the moving width Sd of the screen display area 26A per one scroll operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a client apparatus and a server apparatus that display drawing data generated and transferred from a server apparatus and displayed on the client apparatus with high responsiveness in a server / client system.

  In a conventional server client system, for example, there is a thin client system in which a desired application program is activated and executed on the server device side by remote operation from the client device. In this thin client system, display drawing data that is processed and updated on the server device side in response to an operation input of the client device is transmitted and transferred from the server device to the client device every time the drawing is updated. . As a result, the client device only needs to have a minimum function such as display and input, and resources such as applications are centrally managed by the server device.

  Thus, since the thin client system executes the application program on the server device, it is possible to realize a highly functional computing environment even when the performance of the client device is low. For this reason, it is expected that an advanced computing environment in mobile will be realized by using, as a client device, a terminal having a lower performance than a PC (Personal Computer) such as a mobile phone.

As one form of this thin client system, for example, when a server device is accessed from a mobile phone and the Web content opened by the Web browser of the server device is transferred to the mobile phone and displayed, the mobile phone Since the display screen size is small, it is considered that the server area reduces the screen area of the Web content corresponding to the display instruction position from the mobile phone according to the small terminal display screen size, and transfers and displays it ( For example, see Patent Document 1.)
JP 2004-348380 A

  It is known that the data transmission delay time of a cellular phone network is several hundred times longer than, for example, a LAN (Local Area Network), and as described above, a thin client system is used in the cellular phone network. In this case, there is a problem that the transmission delay time of this network becomes a bottleneck and the operation response is not good.

  Specifically, when a scrolling display of a part of the web content transferred from the server device in accordance with the display screen of the mobile phone is performed according to the user operation of the mobile phone, the scroll operation is accompanied. Each time a screen movement request is transmitted to the server apparatus, a new screen area corresponding to the movement range is received from the server apparatus 10 and displayed. However, each time the scroll operation is performed, a new screen area is received. In this case, there is a problem that a response is poor and a waiting time is generated from the transmission delay time each time.

  The present invention has been made in view of the above problems, and in a thin client system, a client device and a server device capable of scrolling display with good operation response even in a network environment with a large transmission delay. The purpose is to provide.

The client device according to claim 1 is a thin device comprising a client device having a virtual screen memory having a size larger than the screen size of the display screen and a server device storing display data having a size larger than the virtual screen memory of the client device. A client device of a client system,
Display control means for reading display data corresponding to the screen size of the display screen from the virtual screen memory and displaying the display data on the display screen, scroll instruction means for instructing scrolling according to a user operation, and scrolling by the scroll instruction means Scroll display control means for causing the display control means to read out display data from the virtual screen memory by the display control means for scroll display, and display data scrolled by the display control means according to the control of the scroll display control means. Boundary determining means for determining whether or not the screen area of the display data has reached a scroll boundary preset in the virtual screen memory when read from the virtual screen memory and displayed on the display screen; The display screen by this boundary judgment means When it is determined that the screen area of the displayed display data has reached the scroll boundary, scroll request means for requesting the server device to scroll, and in response to a scroll request by the scroll request means, the scroll request means Virtual screen updating means for updating the contents of the virtual screen memory with display data received from the server device.

  The client device according to claim 2 is the client device according to claim 1, wherein the scroll boundaries are provided corresponding to upper and lower ends in the virtual screen memory area, and an upper scroll boundary and a lower scroll boundary thereof. Is set to be larger than the sum of the height of the display screen and the scroll width of the display data received from the server device by the virtual screen updating means.

  The client device according to claim 3 is the client device according to claim 1, wherein the scroll boundary is provided corresponding to both left and right ends in the virtual screen memory area, and the left scroll boundary and the right scroll boundary thereof. Is set to be larger than the sum of the horizontal width of the display screen and the scroll width of the display data received from the server device by the virtual screen updating means.

The server device according to claim 4 comprises a client device having a virtual screen memory having a size larger than the screen size of the display screen and a server device for storing display data having a size larger than the virtual screen memory of the client device. A server device of a client system,
Virtual screen data transmitting means for transmitting display data having a size corresponding to the size of the virtual screen memory of the client device to the client device, and larger than the scroll width per unit in response to a scroll request from the client device Scroll control means for sending display data scrolled by width to the client device by the virtual screen data sending means is provided.

  The server device according to claim 5 is the server device according to claim 4, wherein the scroll control unit is transmitting to the client device in response to a request for one scroll from the client device. Display data that has been scrolled from the display data by a scroll width of a plurality of times is transmitted to the client device by the virtual screen data transmission means.

  According to the present invention, it is possible to provide a client device and a server device that enable scroll display with good operation response even in a network environment with a large transmission delay in a thin client system.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a thin client system according to an embodiment of the present invention.

  This thin client system includes a server device 10 and a plurality of client devices 20,... Connected on a network NET formed of a LAN (Local Area Network), a WAN (Wide Area Network), or a mobile phone network.

  The server device 10 has a plurality of application programs such as a document creation processing program, a spreadsheet processing program, a presentation material creation program, a mail processing program, an Internet connection processing program, and a Web display program, and is connected to the server device 10. It is activated in response to an operation input (input event) signal from the client device 20,.

  In this server device 10, the display output drawing data generated in accordance with the execution of the application program in response to the operation input signal from the client device 20,... Is compressed and transmitted to the access source client device 20. (Transfer).

  In the client devices 20,..., The drawing data transferred from the server device 10 is decompressed and displayed on the display unit.

  That is, each client device 20,... In this thin client system has an input function according to user operations such as a keyboard and a mouse and an output function to an LCD display unit and a printer as main functions. The server apparatus 10 does not have at least various application functions and data file management functions.

  And the data file produced | generated with the various processes started and performed in the server apparatus 10 according to the operation input (input event) signal from the client apparatus 20 ... is fundamentally in the said server apparatus 10. Alternatively, it is stored and stored for each user account or as a shared file in a storage device such as a magnetic disk managed and managed by the server device 10.

  FIG. 2 is a block diagram showing a circuit configuration of the server apparatus 10 in the thin client system.

  The server device 10 includes a CPU 11 serving as a computer. A ROM 13, a RAM 14, an external storage device 15, and a display device 16 are connected to the CPU 11 via a bus 12, and a key input device 17 such as a keyboard and a mouse, A communication I / F (interface) 18 with the client device 20 is connected.

  The CPU 11 controls the operation of each part of the circuit by using the RAM 14 as a working memory in accordance with a system program stored in the ROM 13 in advance and various application programs, and via a key input signal from the key input device 17 and a communication I / F 19. The various programs are activated and executed in response to a processing command signal corresponding to a user operation (input event) from the client device 20 received in this manner.

  In this server device 10, various data generated according to an application program that is activated and executed in response to an input event signal from the terminal device 20 is stored in the external storage device 15 in association with the user ID, for example, The drawing data for display is generated using the display memory in the RAM 14, is compressed, transferred from the communication I / F 18 to the client device 20, and is displayed and output.

  FIG. 3 is a block diagram showing a circuit configuration of the client device 20 in the thin client system.

  The client device 20 includes a CPU 21 as a computer. A ROM 23 and a RAM 24 are connected to the CPU 21 via a bus 22, and an input device 25 such as a keyboard and a mouse, a display device 26, and the server device 10 are connected. A communication I / F (interface) 27 is connected.

  The CPU 21 controls the operation of each part of the circuit using the RAM 24 as a working memory in accordance with a system program stored in advance in the ROM 23. The server device 10 is received via an input signal from the input device 25 or the communication I / F 27. The system program is activated and executed in accordance with an application response signal, transfer drawing data, and the like.

  In the client device 20, various data generated by executing the application program in the server device 10 is appropriately read and stored in the external storage device 15, and the generated drawing data for display is The compressed data is decompressed, written to the display memory in the RAM 24, and displayed on the display device 26.

  Here, the display drawing data generated in the display memory in the RAM 14 in the server device 10 includes, for example, the above-described drawing data out of all the contents (contents) 10A as shown in FIG. A virtual screen area 10B corresponding to the memory size of the display memory in the client device 20 is set, and drawing data in the virtual screen area 10B is read out and transferred to the client device 20. In the client device 20, the drawing data transferred as the virtual screen area 10B is written into the display memory in the RAM 24, and only the drawing data in the range corresponding to the screen display area 26A of the display device 26 is read out. Displayed.

  FIG. 4 shows a drawing content 10A opened by the server apparatus 10 of the thin client system, a virtual screen area 10B transferred to the client apparatus 20, and a screen display area 26A actually displayed on the client apparatus 20. It is a figure which shows a relationship according to each state of the screen scroll to a downward direction.

  In this thin client system, when the drawing content 10A opened by the server device 10 in response to an event input from the client device 20 is transferred to the client device 20, the screen display area of the display device 26 in the client device 20 is displayed. A virtual screen area 10B larger than 26A is set and the drawing data is transferred. Further, the drawing data of the virtual screen area 10B transferred to the client device 20 has an upper scrolling boundary 20u left by a preset width from the upper end thereof, and a preset width from the lower end thereof. The remaining downward scrolling boundary 20d is set, and when the screen display area 26A reaches the downward scrolling boundary 20d as the screen display area 26A scrolls downward, the server apparatus 10 A request for scrolling the contents of the virtual screen area 10B downward is transmitted to the screen display area 26A. Similarly, the screen display area 26A reaches the upper scrolling boundary 20u as the screen display area 26A is scrolled upward. The server device 10 needs to scroll the contents of the virtual screen area 10B upward. To send.

  FIG. 5 is a diagram showing screen scroll management data 24 a stored in the RAM 24 of the client device 20.

  As the screen scroll management data 24a, the height Hd of the screen display area 26A according to the display screen size of the display device 26, the height Hv of the virtual screen area 10B, the height Hc of the drawing content 10A, the upper end of the virtual screen area 10B The width Bd up to the lower scrolling boundary 20d and the width Bu up to the upper scrolling boundary 20u, the movement width (unit movement width) Sd of the screen display area 26A according to one user scroll operation, the server device 10 , The scroll width Ss of the virtual screen area 10B in response to a single scroll request, the offset width Ocv from the upper end of the drawing content 10A to the upper end of the virtual screen area 10B, and the offset width Ovd from the upper end of the virtual screen area 10B to the upper end of the screen display area 26A. Are always updated and stored It is.

  Here, the height Hv of the virtual screen area 10B, the unit movement width Sd of the screen display area 26A according to one user scroll operation, and the scroll of the virtual screen area 10B according to one scroll request to the server device 10 The width Ss, the width Bd from the upper end of the virtual screen area 10B to the boundary 20d when scrolling downward, and the width Bu until the boundary 20u when scrolling upward are expressed by the following conditional expressions (Expression 1) (Expression 2) (Expression 3). Set to meet.

Hv> Hd (Formula 1)
Ss ≧ N × Sd (where N is an integer of 2 or more) (Formula 2)
Bd−Bu> Hd + Ss (Formula 3)
As shown in (Formula 1), by making the height Hv of the virtual screen area 10B larger than the height Hd of the screen display area 26A, it is possible to serve as a prefetch cache. In the present embodiment, by controlling the screen display area 26A to always be scrolled in the virtual screen area 10B, scroll display with good operation response that is not affected by the communication response with the server device 10 is realized. To do.

  As shown in (Formula 2), the scroll width Ss of the virtual screen area 10B in response to one scroll request to the server device 10 is set to the unit movement width Sd of the screen display area 26A in response to one user scroll operation. When the scroll operation is continuously performed in the same direction, the scroll request to the server apparatus 10 is prevented from being generated each time, and the frequency of communication with the server apparatus 10 is increased. Can be reduced to 1 / N or less. Note that the value of N is set to an integer of 2 or more. However, the N value may be automatically variably set according to the memory usage status of the client device 20 and the frequency of scroll operations by the user. In this case, the N value is set to a large value when the memory capacity is sufficient or the scroll operation frequency is large, and to a small value when the memory capacity is not sufficient or the scroll operation frequency is small.

  As shown in (Formula 3), the interval (Bd−Bu) between the upper scrolling boundary 20u and the lower scrolling boundary 20d in the virtual screen area 10B is set to the height Hd of the screen display area 26A and the virtual screen area. By making it larger than the sum of the scroll width Ss of 10B, when the operation direction is reversed upside down in accordance with the user scroll operation, at least N times (from the reverse of the operation until the scroll request is issued to the server device 10) In the scroll operation of (Ss ≧ N × Sd), there is no need to send a scroll request to the server device 10, and scroll display can be performed only by reading the drawing data from the virtual screen area 10B existing in the client device 20. . Thereby, for example, when the user performs an operation such as browsing the drawing content 10A in a short width up and down, there is no need to communicate between the client device 20 and the server device 20, and the mobile communication network Even when using a communication network with a large transmission delay such as NET, scroll display can be performed with good operation response.

  Next, a display control operation in the thin client system having the above configuration will be described.

  FIG. 6 is a flowchart showing client processing (part 1) by the client device 20 of the thin client system.

  FIG. 7 is a flowchart showing client processing (part 2) by the client device 20 of the thin client system.

  FIG. 8 is a flowchart showing client processing (part 3) by the client device 20 of the thin client system.

  When a browsing request for desired content is transmitted from the client device 20 to the server device 10, a notification indicating that the drawing content 10A has been opened is received from the server device 10 in response to the request (step S1). ).

  Next, the height Hc of the opened drawing content 10A and the offset width Ocv from the upper end of the drawing content 10A to the upper end of the virtual screen area 10B are received from the server device 10 and stored as screen scroll management data 24a (step S2, S2). S3).

  Here, the content being opened means that an application operating on the server device 10 has opened a file or the like, or has opened a content different from the content that has been opened so far in the same application. Specifically, when a web page is opened by a web browser, when jumping to another web page, when a document file is opened by an editor or word processor software, etc., each notification is received from the server device 10. .

  Note that the virtual screen area 10B in the present embodiment has the same size as a window of an application operating on the server device 10 (a window in which an application program displays content).

  Next, in the client device 20, the offset width Ovd from the upper end of the virtual screen area 10B to the upper end of the screen display area 26A is stored as the screen scroll management data 24a (step S4).

  Then, the client device 20 updates the virtual screen area 10B in the display memory in the RAM 24 with the drawing data received from the server apparatus 10, and then displays the screen from the position of the offset width Ovd from the upper end of the virtual screen area 10B. Drawing data for the height Hd of the area 26A is read and displayed on the display device 26 (step S5).

  This state corresponds to the initial state when the drawing content 10A is opened, for example, as shown in FIG.

  After the initial display of the drawing data, the client device 20 enters a standby state for receiving update screen (drawing) data from the server device 10 (step S6) or a standby state for a scroll operation by the user (step S7).

  If a downward scroll operation is determined in accordance with user input (step S8 (Yes)), the screen display area 26A is displayed on the virtual screen area 10B as shown in FIG. 4B. The unit is moved downward by the unit width Sd. That is, the offset width Ovd from the upper end of the virtual screen area 10B to the upper end of the screen display area 26A is updated to Ovd + Sd (step S10), and the drawing in the virtual screen area 10B corresponding to the screen display area 26A at the position after the movement update is performed. Data is read out and displayed on the display device 26 (step S11).

  When the downward scroll operation is determined (step S8 (Yes)), the width (Ovd + Hd) from the height Hv of the virtual screen area 10B to the lower end of the screen display area 26A is subtracted each time. It is determined whether or not the remaining width has reached the moving width Sd or less of the screen display area 26A corresponding to one user scroll operation (step S9), and this state (see FIG. 4F) has been reached. If it is determined (step S9 (Yes)), since the scroll process for the movement width Sd cannot be performed, the process branches to the process after step S24.

  On the other hand, by repeating the downward scroll display of the screen display area 26A for the moving width Sd accompanying the downward scroll operation in the step S11 (steps S11, S12 (No) → S6 (No), S7 (Yes)). , S8 (Yes), S9 (No), S10, S11), it is determined that the lower end (Ovd + Hd) of the screen display area 26A has reached the position (Bd) of the downward scrolling boundary 20d set in the virtual screen area 10B. If it is determined (step S12 (Yes)), the remaining width (Hc−Hv) obtained by subtracting the height Hv of the virtual screen area 10B from the height Hc of the drawing content 10A is further from the upper end of the virtual screen area 10B. By determining whether or not the offset width Ovd to the upper end of the screen display area 26A is equal to the virtual screen, Emission region 10B is determined whether the host vehicle has reached the lowermost end of the drawing content 10A (step S13).

  Here, when it is determined that the virtual screen area 10B has not yet reached the lowermost end of the drawing content 10A (step S13 (No)), a flag Fd indicating a downward scroll operation is set. At the same time (step S14), a downward scroll request for the virtual screen area 10B is transmitted to the server device 10 (step S15), and reception of scrolled update screen (drawing) data from the server device 10 is awaited. A state is reached (step S6).

  Thereafter, when updated screen (drawing) data obtained by scrolling the virtual screen area 10B for the drawing content 10A downward by the movement width Ss is received from the server device 10 (step S6 (Yes)), the display memory in the RAM 24 is displayed. The contents of the virtual screen area 10B are updated (step S16).

  If it is determined that the flag Fd indicating the downward scroll operation is set (step S17 (Yes)), the width from the height Hc of the drawing content 10A to the lower end of the virtual screen region 10B It is determined whether the remaining width obtained by subtracting (Ocv + Hv) has reached the scroll width Ss of the virtual screen area 10B corresponding to one scroll request to the server device 10 (see FIG. 4D) (step D). S18).

  Here, for example, as shown in FIG. 4C, the remaining width obtained by subtracting the width (Ocv + Hv) from the height Hc of the rendering content 10A to the lower end of the virtual screen region 10B is one scroll request to the server device 10. If it is determined that it has not yet reached the scroll width Ss or less of the virtual screen area 10B according to (step S18 (No)), the offset width Ovd from the upper end of the virtual screen area 10B to the upper end of the screen display area 26A is The update is performed according to the scroll width Ss of the virtual screen area 10B (step S19), and the offset width Ocv from the upper end of the drawing content 10A to the upper end of the virtual screen area 10B is also updated according to the scroll width Ss of the virtual screen area 10B. (Step S20).

  Then, the flag Fd is cleared (step S21), the next update screen (drawing) data reception waiting state from the server device 10 (step S6), or the standby state for the next scroll operation by the user (step S7). Become.

  Thereafter, the scroll display is scrolled down N times for each moving width Sd of the screen display area 26A when the lower end of the screen display area 26A does not reach the downward scrolling boundary 20d set in the virtual screen area 10B. Processing (Steps S7 (Yes) to S12 (No) → S6) and scrolling downward in the virtual screen area 10B with respect to the server device 10 when the lower end of the screen display area 26A reaches the boundary 20d when scrolling downward in the same direction The request process (steps S7 (Yes) to S15) and the content update process (step S6 (Yes) → S16 to S21) of the virtual screen area 10B by the update screen (drawing) data received from the server device 10 in connection with this request process. By being repeated, for example, as shown in FIG. 4D, from the height Hc of the drawing content 10A When it is determined that the remaining width obtained by subtracting the width (Ocv + Hv) to the lower end of the virtual screen area 10B has reached the scroll width Ss of the virtual screen area 10B corresponding to one scroll request to the server device 10 (Step S18 (Yes)), the content update process of the virtual screen region 10B this time causes the lower end of the virtual screen region 10B to reach the lower end of the rendering content 10A as shown in FIG. Accordingly, the offset width Ovd from the upper end of the virtual screen area 10B to the upper end of the screen display area 26A is updated according to the remaining width (Hc− (Ocv + Hv)) from the lower end of the virtual screen area 10B to the lower end of the drawing content 10A. (Step S22) Further, a virtual scan is started from the upper end of the drawing content 10A. Offset width Ocv to lean region 10B upper is also updated according to the height Hv of the same virtual screen region 10B (step S23).

  Then, the flag Fd is cleared (step S21), the next update screen (drawing) data reception waiting state from the server device 10 (step S6), or the standby state for the next scroll operation by the user (step S7). Become.

  Thus, after the virtual screen area 10B has reached the lower end of the drawing content 10A (Ocv = Hc−Hv), the scroll display process in the downward direction of the screen display area 26A is repeated (steps S7 to S13). (Yes) → S6), as shown in FIG. 4F, the remaining width (Hv− (Ovd + Hd)) from the lower end of the screen display area 26A to the lower end of the virtual screen area 10B is one user scroll operation. When it is determined that the movement width Sd or less of the corresponding screen display area 26A has been reached (step S9 (Yes)), the lower end of the screen display area 26A has further reached the lower end of the virtual screen area 10B (Hv− ( It is determined whether or not Ovd + Hd) = 0) (step S24).

  If it is determined that the lower end of the screen display area 26A has not yet reached the lower end of the virtual screen area 10B (step S24 (No)), as shown in FIG. 4G, the screen display area 26A is displayed. The upper end offset width Ovd with respect to the virtual screen area 10B is updated as a state where the screen display area 26A reaches the lower end of the virtual screen area 10B (Ovd = Hv−Hd) (step S25).

  Then, drawing data corresponding to the height Hd of the screen display area 26A is read from the lower end of the virtual screen area 10B and displayed on the display device 26 (step S26).

  On the other hand, when the downward scroll operation is determined (step S8 (Yes)), on the other hand, when the upward scroll operation is determined (step S8 (No)), the step S9 is performed. Upward scroll display processing is executed in steps S9u to S15u and S24u to S26u as shown in FIG. 7, which is the same method as the downward scroll display processing described in S15 and S24 to S26. .

  Further, in accordance with the upward scroll display process, the updated screen (drawing) data after the upward scroll is received from the server device 10 in response to the upward scroll request of the virtual screen area 10A (step S6). (Yes)) When the contents of the virtual screen area 10B are updated (step S16), the same method as the update process of the screen scroll management data 24a accompanying the downward scroll described in steps S18 to S23. As shown in FIG. 8, the update processing of the screen scroll management data 24a accompanying the downward scroll in steps S18u to S23u is executed.

  That is, each time an upward scroll operation is determined, first, the screen display area 26A in the virtual screen area 10B is scrolled upward by the unit movement width Sd and displayed on the display device 26 (steps S7 and S8). (No) → S9u to S12u (No) → S6).

  With this upward scroll display processing, the downward scroll flag Fd is cleared each time the upper end of the image display area 26A reaches the upward scrolling boundary 20u set in the virtual screen area 10B, and the virtual screen is displayed. A request signal for scrolling the area 10B upward with the movement width Ss (≦ N × Sd) is transmitted to the server device 10 (steps S12u (Yes) to S15u → S6).

  Thereby, update screen (drawing) data in a state where the virtual screen area 10B is scrolled upward by the movement width Ss from the server device 10 is received, and the contents of the virtual screen area 10B in the display memory in the RAM 24 are updated. Then (step S6 (Yes) → S16), according to the fact that the downward scroll flag Fd is cleared (step S17 (No)), the offset width Ovd from the upper end of the virtual screen area 10B to the upper end of the screen display area 26A, The offset width Ocv from the upper end of the drawing content 10A to the upper end of the virtual screen area 10B is updated according to the scroll width Ss of the virtual screen area 10B (steps S18u to S20u).

  Thereafter, when the remaining width from the upper end of the virtual screen area 10B scrolled upward to the upper end of the drawing content 10A reaches the scroll width Ss of the virtual screen area 10B (step S6 (Yes) → S16). , S17 (No) → S18u (Yes)), the offset width Ovd at the upper end of the screen display area 26A and the offset width at the upper end of the virtual screen area 10B according to the state in which the virtual screen area 10B has reached the upper end of the drawing content 10A. Ocv is updated (steps S22u and S23u).

  With the further upward scroll display processing (step S7 (Yes) → S8 (No)), the offset width Ovd at the upper end of the screen display area 26A has reached the unit movement width Sd or less accompanying one scroll operation. In this case (step S9u (Yes)), the offset width Ovd at the upper end of the screen display area 26A is updated in accordance with the state where the screen display area 26A has reached the upper end of the virtual screen area 10B (step S26u). The drawing data is read and scrolled (step S26u).

  As described above, in the client device 20, scroll display processing in both the up and down directions is performed in a state where drawing data at the next scroll destination in the screen display area 26 </ b> A is always prefetched in the client device 20. For this reason, it is possible to perform scroll display processing with good operation response without being affected by the transmission delay time on the network NET with the server device 10 when scrolling the virtual screen area 10B.

  FIG. 9 is a flowchart showing server processing by the server apparatus 10 of the thin client system.

  When the application program is started in response to a request for browsing the desired content from the client device 20 and it is determined that the drawing content 10A is opened (step A1 (Yes)), the height of the drawing content 10A is determined. Hc is acquired (step A2), and an offset width Ocv from the upper end of the drawing content 10A to the upper end of the virtual screen area 10B currently displayed in the window is acquired (step A3).

  Then, the client device 20 is notified that the requested content has been opened, and the height Hc of the drawing content 10A acquired in steps A2 and A3, and the offset width of the upper end of the virtual screen region 10B. Ocv is transmitted (step A4). Next, the screen data for the virtual screen of the client is transmitted to the client device 20 (step A5). This screen data is the opened content, which is the content for the virtual screen of the client.

  When a scroll request is received from the client device 10 (step A6 (Yes)), it is determined whether the scroll request is a downward scroll request or an upward scroll request (step A7). If it is determined that the request is a downward scroll (step A7 (Yes)), the virtual screen area 10B is moved downward by one unit movement width Sd with respect to the activated application program. A scroll request event is issued N times in succession, and the virtual screen area 10B is scrolled downward with a movement width Ss (= N × Sd) (step A8).

  Then, the drawing data corresponding to the downward scrolling, that is, the drawing data for N times the unit movement width Sd at one time is read out and transmitted to the client device 20 as the scroll request source (step A9). As a result, display data scrolled with a width larger than the scroll width per unit is transmitted to the client device 20.

  On the other hand, also when it is determined that the scroll request is an upward scroll (step A7 (No)), the virtual screen area 10B is moved upward once by the unit movement width Sd with respect to the application program being activated as described above. A scroll request event is issued N times in succession, and the virtual screen area 10B is scrolled upward with a movement width Ss (= N × Sd) (step A10).

  Then, the drawing data corresponding to the upward scroll is read and transmitted to the client device 20 that is the scroll request source (step A11). As a result, display data scrolled with a width larger than the scroll width per unit is transmitted to the client device 20.

  Therefore, according to the scroll display control function in the thin client system having the above-described configuration, the height Hv of the virtual screen area 10B is made larger than the height Hd of the screen display area 26A, and the upper and lower ends of the virtual screen area 10B. A boundary line 20u for upward scrolling and a boundary line 20d for downward scrolling are provided at a position that is a width before the width set from the left side, and the upper end of the screen display area 26A is scrolled upward when scrolling upward. Only when the boundary line 20u is reached, a scroll request for the virtual screen area 10B is transmitted to the server apparatus 10, and the lower end of the screen display area 26A is the boundary at the time of the downward scroll during the downward scroll operation. Only when the line 20d is reached, the server screen 10 is scanned for the virtual screen area 10B. To send a roll request. The scroll width Ss of the virtual screen area 10B accompanying one scroll request to the server device 10 is N times or more than the unit movement width Sd of the screen display area 26A per scroll operation (Ss ≧ N × Sd), for example, it is necessary to exchange a scroll request and drawing data between the client device 20 and the server device 10 every time the scroll operation is performed even in a continuous scroll operation in the same direction. The communication frequency can be reduced to 1 / N or less. For this reason, even in an environment using a network NET with a large transmission delay, it is possible to perform scroll display with good operation response without being affected by this.

  Further, according to the scroll display control function in the thin client system having the above-described configuration, the interval (Bd) between the boundary line 20u when scrolling upward and the boundary line 20d when scrolling downward is set in the virtual screen area 10B. −Bu) is set to be larger than the sum of the height Hd of the screen display area 26A and the scroll width Ss (≧ N × Sd) of the virtual screen area 10B. When an operation in which the scroll direction is changed, such as a downward operation from the operation or vice versa, is performed N times immediately after the change in the operation direction (the crawl width Ss of the virtual screen area 10B ÷ the screen display area) For a scroll operation with a scroll width Sd) of 26A, it is necessary to send a scroll request to the server device 10. There is no need. Thus, for example, when the user performs an operation such as browsing the content up and down with a short width, there is no need to communicate between the client device 20 and the server device 10, and the communication network has a large transmission delay. Even during use, it is possible to perform scroll display with good operation response.

  In the above embodiment, as shown in FIG. 4, the display corresponding to the scroll operation in the vertical direction is taken as an example in which the widths of the drawing content 10A, the virtual screen area 10B, and the screen display area 26A are all equal. Although only the control function has been described, display control including a horizontal scroll operation can be performed in the same manner as shown in FIG.

  FIG. 10 shows a drawing content 10A opened by the server apparatus 10 of the thin client system, a virtual screen area 10B transferred to the client apparatus 20, and a screen display area 26A actually displayed on the client apparatus 20. It is a figure which shows a relationship with each management data required for the scroll control of an up-down direction and a left-right direction.

  That is, when performing display control including horizontal scroll operation in addition to display control according to the vertical scroll operation, a new preset width is left from the left end of the virtual screen area 10B. The left scrolling boundary 20l and the right scrolling boundary 20r left by a preset width from the right end are set. Then, the horizontal width Wd of the screen display area 26A, the horizontal width Wv of the virtual screen area 10B, the horizontal width Wc of the drawing content 10A, the width B1 from the left end of the virtual screen area 10B to the left scrolling boundary 20l, and the right scrolling boundary 20r , The offset width Och from the left end of the rendering content 10A to the left end of the virtual screen area 10B, and the offset width Ohd from the left end of the virtual screen area 10B to the left end of the screen display area 26A are added as the screen scroll management data 24a.

  As a result, even for the scroll operation in the left-right direction, by performing the same processing as the display control according to the above-described scroll operation in the up-down direction, it is possible to perform scroll display with good operation response in the up-down, left-right direction.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, each of the embodiments includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in each embodiment or some constituent elements are combined in different forms, the problems described in the column of the problem to be solved by the invention If the effects described in the column “Effects of the Invention” can be obtained, a configuration in which these constituent requirements are deleted or combined can be extracted as an invention.

The figure which shows the whole structure of the thin client system which concerns on embodiment of this invention. The block diagram which shows the circuit structure of the server apparatus 10 in the said thin client system. The block diagram which shows the circuit structure of the client apparatus 20 in the said thin client system. The relationship between the drawing content 10A opened by the server apparatus 10 of the thin client system, the virtual screen area 10B transferred to the client apparatus 20, and the screen display area 26A actually displayed on the client apparatus 20 is downward. The figure shown according to each state of the screen scroll to. The figure which shows the screen scroll management data 24a memorize | stored in RAM24 of the said client apparatus 20. FIG. The flowchart which shows the client process (the 1) by the client apparatus 20 of the said thin client system. The flowchart which shows the client process (the 2) by the client apparatus 20 of the said thin client system. The flowchart which shows the client process (the 3) by the client apparatus 20 of the said thin client system. The flowchart which shows the server process by the server apparatus 10 of the said thin client system. The relationship between the drawing content 10A opened by the server apparatus 10 of the thin client system, the virtual screen area 10B transferred to the client apparatus 20, and the screen display area 26A actually displayed on the client apparatus 20 is determined in the vertical direction. The figure shown with each management data required for horizontal scroll control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Server apparatus 10A ... Drawing content 10B ... Virtual screen area | region 11 ... Server CPU
13: Server ROM
14: Server RAM
DESCRIPTION OF SYMBOLS 15 ... External storage device 16 ... Server display device 17 ... Server input device 18 ... Server communication I / F
20 ... Client device 20u ... Upward scroll boundary 20d ... Downward scroll boundary 20l ... Left scroll boundary 20r ... Right scroll boundary 21 ... Client CPU
23 ... Client ROM
24 ... Client RAM
24a ... Screen scroll management data 25 ... Client input device 26 ... Client display device 26A ... Screen display area 27 ... Client communication I / F
NET ... communication network

Claims (5)

A client device of a thin client system comprising a client device having a virtual screen memory having a size larger than the screen size of the display screen and a server device storing display data having a size larger than the virtual screen memory of the client device,
Display control means for reading display data corresponding to the screen size of the display screen from the virtual screen memory and displaying the display data on the display screen;
Scroll instruction means for instructing scrolling in response to a user operation;
Scroll display control means for causing the display control means to read display data corresponding to the scroll instruction by the scroll instruction means from the virtual screen memory and scroll-displaying the display data;
When display data scrolled by the display control means is read from the virtual screen memory and displayed on the display screen according to the control of the scroll display control means, the screen area of the display data is stored in the virtual screen memory. Boundary determination means for determining whether or not a preset scroll boundary has been reached;
Scroll requesting means for requesting scrolling to the server device when it is determined by the boundary determining means that the screen area of the display data displayed on the display screen has reached the scroll boundary;
Virtual screen update means for updating the contents of the virtual screen memory with display data received from the server device in response to a scroll request by the scroll request means;
A client device comprising: The scroll boundary is provided corresponding to the upper and lower ends of the virtual screen memory area,
The interval between the upper scroll boundary and the lower scroll boundary is set larger than the sum of the height of the display screen and the scroll width of the display data received from the server device by the virtual screen scroll means.
The client device according to claim 1. The scroll boundary is provided corresponding to the left and right ends of the virtual screen memory area,
The interval between the left scroll boundary and the right scroll boundary is set larger than the sum of the horizontal width of the display screen and the scroll width of the display data received from the server device by the virtual screen scroll means.
The client device according to claim 1. A thin client system server device comprising a client device having a virtual screen memory having a size larger than the screen size of the display screen and a server device storing display data having a size larger than the virtual screen memory of the client device,
Virtual screen data transmitting means for transmitting display data of a size corresponding to the size of the virtual screen memory of the client device to the client device;
Scroll control means for causing the virtual screen data transmission means to transmit display data scrolled with a width larger than the scroll width per unit in response to a scroll request from the client apparatus;
A server device comprising: In response to a single scroll request from the client device, the scroll control means converts display data scrolled by a plurality of scroll widths from display data being transmitted to the client device, and transmits the virtual screen data. To send to the client device,
The server device according to claim 4, wherein:

Images