Display control device, operation display device and display control method

Abstract

To select a page prepared for screen switching.SOLUTION: An operation display device (1) comprises a browser part (5) which controls a display panel (16) so that a screen is displayed at a forefront tab (T1) as a forefront page area by a browser function. The browser part (5) comprises: a specifying part (52) which specifies at least one switching candidate page as a page which can be switched from a page displayed at the forefront tab (T1) using a search word in a search word list L1; and a drawing part (53) which draws the switching candidate page specified by the specifying part as at least one back tab (T2) provided as a back page area of the forefront tab (T1).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a display control device that displays a prepared screen on a display device. [Background technology]

[0002] A display device with a browser function can switch between multiple Web pages and display them in the foreground in response to a user's operation. For example, Patent Document 1 describes a mobile terminal that acquires a file specified by a link set in a displayed hypertext document A, and generates a back tab based on the file to display another page behind a front tab. The mobile terminal switches the display from the displayed hypertext document A in the front tab to the hypertext document B in the back tab in response to a user's key operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-242842 A Summary of the Invention [Problem to be solved by the invention]

[0004] Since the above-mentioned mobile terminal obtains the hypertext document present on the back tab as a file designated by the above-mentioned link, it is not possible to select the desired hypertext document.

[0005] An object of one aspect of the present invention is to select a page to be prepared for screen switching. [Means for solving the problem]

[0006] In order to solve the above problem, a display control device according to one embodiment of the present invention includes a control unit that controls a display device to display a screen in a first page area, which is the foreground page area, using a browser function, and the control unit includes an identification unit that identifies at least one switching candidate screen, which is a screen that can be switched to from the screen displayed in the first page area, using screen identification information that identifies the switching candidate screen, and a drawing unit that draws the switching candidate screen identified by the identification unit in a second page area, which is provided as at least one page area behind the first page area.

[0007] In order to solve the above problems, a display control method according to one embodiment of the present invention is a display control method that controls a display device to display a screen in a first page area, which is the foreground page area, using a browser function, and includes an identification step of identifying at least one switching candidate screen, which is a screen that can be switched from the screen displayed in the first page area, using screen identification information that identifies the switching candidate screen, and a drawing step of drawing the switching candidate screen identified by the identification step in a second page area, which is provided as at least one page area behind the first page area. Effect of the Invention

[0008] According to one aspect of the present invention, it is possible to select a page to be prepared for screen switching. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a hardware configuration of an operation display system according to first and second embodiments of the present invention. [Diagram 2] 1 is a block diagram showing a functional configuration of an operation display system according to a first embodiment of the present invention. [Diagram 3] 10 is a flowchart showing a procedure of a process performed by a browser unit of the operation display device to previously draw candidate pages for switching that may be displayed on back tabs. [Figure 4]10 is a diagram for explaining a procedure in which the operation display device creates an ID list based on a search word list. FIG. [Diagram 5] 10 is a flowchart showing a procedure of a page switching process performed by the browser unit. [Figure 6] FIG. 13 is a diagram for explaining page switching. [Figure 7] FIG. 11 is a block diagram showing a functional configuration of an operation display system according to a second embodiment of the present invention. [Figure 8] 8 is a flowchart showing a procedure of a process performed by a browser unit of the operation display device shown in FIG. 7 to draw in advance candidate pages to be switched to, on back tabs, which may possibly be displayed. [Figure 9] 8 is a diagram for explaining a procedure in which the operation display device shown in FIG. 7 creates an ID list based on a search word list. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Embodiment 1] Hereinafter, the first embodiment of the present invention will be described in detail.

[0011] <Hardware configuration of the operation display system> FIG. 1 is a block diagram showing a hardware configuration of an operation display system 101 according to the first embodiment.

[0012] 1, the operation display system 101 includes an operation display device 1, a server device 2, and a control device 3. The operation display device 1 and the server device 2 are connected to a network 4 such as the Internet so as to be able to communicate with each other.

[0013] First, the hardware configuration of the operation display device 1 will be described.

[0014] The operation display device 1 is an embedded device that implements a dedicated OS (Operating System). The operation display device 1 is a dedicated machine that realizes an HMI (Human Machine Interface) function by having a browser function that performs operations on the control device 3 and displays a web page (screen) for displaying the status of the control device 3. The operation display device 1 is a computer with enhanced dustproofness, drip-proofness, vibration resistance, etc. to suit harsh environments such as factories.

[0015] The operation display device 1 includes a CPU (Central Processing Unit) 11, a main memory 12, a ROM (Read Only Memory) 13, a display memory 14 (memory), a touch panel 15 (operation unit), a display panel 16 (display device), and a network communication unit 17.

[0016] The operation display device 1 may be a device such as a panel computer that has a general-purpose OS installed.

[0017] The CPU 11 is a processing device that executes a browser program for implementing the browser function of the operation display device 1. Specifically, the CPU 11 performs instruction notification processing, page acquisition processing, and the like. The instruction notification processing is processing for notifying the server device 2 of instruction contents corresponding to operations on the touch panel 15 when the browser program is executed. The page acquisition processing is processing for acquiring data of a Web page (page data) from the server device 2 when a switching candidate page, which will be described later, is drawn in the display memory 14. The page data is configured as an HTML (HyperText Markup Language) file.

[0018] The Web page is a screen including various objects. The objects are provided to display the status of the input / output devices connected to the control device 3 and to accept operations on the touch panel 15. Various component images such as lamp components, data display components, and switch components are provided as objects. By including objects, the Web page plays the role of an HMI screen that realizes HMI functions.

[0019] In the following description, a Web page will simply be referred to as a "page." Also, because a user of the operation display device 1 sees a page as the above-mentioned screen displayed on the display surface of the display panel 16, the page will be referred to as a "screen" as necessary.

[0020] The main memory 12 is a memory constituting the main storage device of the operation display device 1, and is composed of a dynamic random access memory (DRAM). The ROM 13 stores, in addition to the OS, programs essential for the operation of the operation display device 1, such as a basic input output system (BIOS) that is executed when the operation display device 1 is started up and reset.

[0021] The display memory 14 is a VRAM (Video RAM) in which the browser unit 5 (see FIG. 2), which will be described later, expands, in units of pixels, page data constituting a page to be displayed on the display panel 16. If high speed operation is not required for the display memory 14, an area in place of the display memory 14 may be provided in part of the main memory 12.

[0022] Touch panel 15 receives a touch operation on a page displayed on display panel 16 and outputs a touch operation signal as an input signal. Touch panel 15 is disposed on display panel 16, but may be incorporated within display panel 16.

[0023] The display panel 16 is a display device that displays a page based on the page data. A flat display panel such as a liquid crystal display panel or an EL (Electro-Luminescence) display panel is used as the display panel 16. The display panel 16 is incorporated into a housing that forms the exterior of the operation display device 1, but may be configured separately from the housing.

[0024] The network communication unit 17 has a function of performing network communication via the network 4 .

[0025] Next, the hardware configuration of the server device 2 will be described.

[0026] The server device 2 is configured by a computer that implements a general-purpose OS (Operating System), and is communicably connected to the control device 3. The server device 2 has an instruction function, an update function, etc. The instruction function is a function for giving control instructions to the control device 3 based on the above-mentioned instruction contents notified from the operation display device 1. The update function is a function for updating the state of the input device in the page data based on data relating to the state of the input device (described later) obtained from the control device 3.

[0027] The server device 2 includes a CPU (Central Processing Unit) 21, a main memory 22, a ROM (Read Only Memory) 23, an auxiliary storage device 24, a network communication unit 25, and an interface unit .

[0028] CPU 21 is a processing device that executes a Web server program under the control of the OS. Specifically, when executing the Web server program, CPU 21 receives various data from auxiliary storage device 24, network communication unit 25, interface unit 26, etc., and performs predetermined processing on the data. CPU 21 also outputs the results of the processing to network communication unit 25, interface unit 26, etc.

[0029] The main memory 22 is a memory constituting a primary storage device in the server device 2, and is constituted by a dynamic random access memory (DRAM). The ROM 23 stores, in addition to the OS, programs essential for the operation of the server device 2, such as a basic input output system (BIOS) that is executed when the server device 2 is started and reset.

[0030] The auxiliary storage device 24 is provided to store various data, particularly page data PD, to be held by the server device 2. The auxiliary storage device 24 is configured by a hard disk drive (HHD), a solid state drive (SSD), or the like.

[0031] The network communication unit 25 has a function of performing network communication via the network 4 .

[0032] The interface unit 26 is a connection unit for communicatively connecting to the control device 3. The interface unit 26 is appropriately equipped with various interfaces such as a serial interface and a LAN (Local Area Network).

[0033] The control device 3 is a device that controls a PLC (Programmable Logic Controller), a temperature controller, a motor controller, etc., and has a communication function. The control device 3 transmits and receives data to and from input / output devices (not shown). The input / output devices used include input devices such as sensors and switches, and output devices such as actuators, motors, relays, solenoid valves, and displays. The control device 3 has a device memory as a memory for storing the states of the input / output devices.

[0034] Functional Configuration of Operation Display System FIG. 2 is a block diagram showing the functional configuration of the operation display system 101. As shown in FIG.

[0035] First, the functional configuration of the operation display device 1 will be described.

[0036] 2, the operation display device 1 includes a browser unit 5 (control unit). The browser unit 5 is a functional portion realized by the CPU 11 executing a browser program. The browser unit 5 includes a setting unit 51, a specification unit 52, a drawing unit 53, and an operation processing unit 54 (switching unit).

[0037] The browser unit 5 draws pages in multiple overlapping tabs in the display memory 14, and controls the display panel 16 to display the pages in a foreground tab T1 (first page area) that is the foreground page area using a browser function. At least one background tab T2 (second page area) that is a background page area is provided behind the foreground tab T1. The operation display device 1, by being provided with the browser unit 5, functions as a display control device that controls the display panel 16.

[0038] The setting unit 51 sets page specification information (screen specification information). The page specification information is information for specifying a switching candidate page (switching candidate screen) which is a page that can be switched from the page displayed on the foreground tab T1. The setting unit 51 sets a search word list L1 that compiles search words as page specification information for each page.

[0039] The search word list L1 is a list in which at least some of the words that set objects for operating page switching (screen switching) are configured as search words (keywords). The above-mentioned objects are, for example, screen switching switches, and are described in the page data PD prepared in the server device 2. The above-mentioned objects are set with links that indicate the location of the page data PD of the switching candidate pages.

[0040] The search word list L1 is created by a user who uses the operation display device 1 or a company that creates the page data PD. In addition, the setting unit 51 may read the page data PD in advance and extract candidate search words from the page data PD as a preliminary step for creating the search word list L1.

[0041] Instead of setting the search word list L1, the setting unit 51 may create the search word list L1 by extracting the above links in the page data PD as search words. Since "http:" or "https:" is written at the beginning of the link, the setting unit 51 sets them as search words. In this way, the search word list L1 can be created automatically. Alternatively, the setting unit 51 may extract links or keywords of pages that have been displayed in the past, and create the search word list L1 based on them.

[0042] In the example shown in Figure 4, "pageX.html (X=1,2,3,...)" indicates a link. For this link, the above "http:" or "https:" is omitted. This is also the case for the example shown in Figure 9, which will be described later.

[0043] The identification unit 52 identifies at least one switching candidate page by page identification information. Specifically, when displaying a page on the foreground tab T1, the identification unit 52 sets acquisition information for acquiring a switching candidate page based on a search word registered in the search word list L1 in the ID list L2, and identifies the switching candidate page by the acquisition information. The acquisition information is, for example, a link to the page data PD. The identification unit 52 creates the ID list L2 (list) by associating the acquisition information with a tab ID (area identification information) that identifies the back tab T2 on which the switching candidate page is drawn.

[0044] The specification unit 52 registers a tab ID corresponding to the generated back tab T2 after the drawing unit 53 generates the back tab T2 in the display memory 14 and acquires the page data PD from the server device 2 and reads it into the display memory 14. By registering the tab ID after the reading is completed, the registration of the tab ID in the ID list L2 can be used to determine whether the reading is completed.

[0045] Alternatively, the identification unit 52 may register a tab ID corresponding to the generated back tab T2 when the drawing unit 53 generates the back tab T2 in the display memory 14. Alternatively, the identification unit 52 may register a tab ID in the ID list L2 in advance and associate it with a link.

[0046] In the following description, it is assumed that the specification unit 52 registers the tab ID in the ID list L2 after the drawing unit 53 has completed reading the page data PD.

[0047] The drawing unit 53 generates a back tab T2 in the display memory 14, and draws, on the generated back tab T2, a switching candidate page identified by the identification unit 52. Specifically, the drawing unit 53 acquires page data PD from the server device 2 based on the acquisition information (link) registered in the ID list L2, and draws a page on the back tab T2 generated in the display memory 14 based on the page data PD.

[0048] The drawing unit 53 does not draw the switching candidate page when a predetermined condition is satisfied, and draws the switching candidate page when the predetermined condition is not satisfied. The predetermined condition may be a time condition, a display content condition, a change condition, or the like.

[0049] The time condition may be, for example, a condition regarding the read time of the page data PD. The time required to read the page data PD into the display memory 14 varies depending on the size of the page data PD of the switching candidate page. Therefore, when the condition that the read time exceeds a predetermined time is satisfied and there is a high possibility that other processing performed by the operation display device 1 in parallel with the drawing of the switching candidate page will be affected, the drawing unit 53 stops reading and does not perform drawing. On the other hand, when the above condition that the read time is equal to or shorter than the predetermined time is not satisfied, the drawing unit 53 performs reading and drawing. Such a condition regarding the read time is set regardless of the page data PD, but may be set for each page data PD.

[0050] An example of the display content condition is that a specific object is placed on the page. Examples of this condition include that an object that displays important data in real time is placed on the page, and that a momentary switch component is placed on the page. When an object that displays important data in real time is placed on the page, it is necessary to restrict those who can view the data. When a momentary switch component is placed on the page, careless operation of the momentary switch could lead to a serious incident.

[0051] When the condition that such a specific object is placed on the page is satisfied, the drawing unit 53 stops reading and does not perform drawing, and when the condition is not satisfied, the drawing unit 53 performs reading and drawing. When the above condition is satisfied and drawing is not performed, a person permitted to view and operate such a page may perform drawing by entering a password or the like.

[0052] Variable conditions include conditions related to variables such as the load rate of the CPU 11. When the load rate of the CPU 11 is high, it is highly likely that the load rate will affect the processing that the CPU 11 performs with priority over the drawing processing of the drawing unit 53. For this reason, when the condition that the load rate of the CPU 11 is equal to or greater than a predetermined value is satisfied, the drawing unit 53 stops reading and does not perform drawing, and when the condition is not satisfied, the drawing unit 53 performs reading and drawing.

[0053] The above-mentioned various conditions are set by a system designer of the operation display device 1 when setting a search word. Also, the conditions may be set by a user as an operation setting of the browser unit 5 when the operation display device 1 is in operation.

[0054] The operation processing unit 54 switches tabs when a link corresponding to the page to be switched and displayed is registered in the ID list L2 created by the identification unit 52. Specifically, the operation processing unit 54 switches at least one back tab T2 on which a switching candidate page is drawn, among switching candidate pages drawn on the back tab T2 in the display memory 14, with the foreground tab T1. The switching back tab T2 has a switching candidate page designated by a touch operation accepted by the touch panel 15 drawn on it. The operation processing unit 54 causes the display panel 16 to display the page drawn on the back tab T2 switched from the foreground tab T1 in the display memory 14.

[0055] If the tab ID corresponding to the page to be switched to and displayed is not registered in the ID list L2 created by the identification unit 52, the operation processing unit 54 acquires the corresponding page data PD from the server device 2 in response to the touch operation. The operation processing unit 54 displays the page to be switched to on the display panel 16 based on the acquired page data PD.

[0056] When a control instruction is given to the control device 3 in response to a user's operation of the touch panel 15 on a page displayed on the display panel 16, the operation processing unit 54 notifies the server device 2 of the control instruction. In addition, when the operation processing unit 54 receives updated page data PD from the server device 2, it causes the display panel 16 to display the page based on the page data PD.

[0057] Next, the functional configuration of the server device 2 will be described.

[0058] The server device 2 includes a Web server unit 7 and an HMI control unit 8 .

[0059] In response to a request for page data PD based on information acquired by drawing section 53 of operation display device 1, Web server section 7 performs a process of acquiring the corresponding page data PD from page data PD stored in auxiliary storage device 24 and transmitting the acquired page data PD to operation display device 1. Furthermore, upon receiving a control instruction from operation processing section 54 of operation display device 1, Web server section 7 transmits the control instruction to HMI control section 8. Furthermore, based on update data from control device 3 acquired from HMI control section 8, Web server section 7 rewrites the contents of page data PD corresponding to the data in auxiliary storage device 24 and transmits the updated page data PD to operation display device 1.

[0060] Based on the above control instruction, the HMI control unit 8 instructs the control device 3 to rewrite the contents of the device memory via the interface unit 26. The HMI control unit 8 acquires the above update data, which is periodically transmitted from the control device 3 and which updates the contents of the device memory, and transfers it to the Web server unit 7.

[0061] <Drawing on the back tab> Fig. 3 is a flowchart showing a procedure (display control method) of a process for drawing in advance switching candidate pages that may be displayed on the back tab T2 by the browser unit 5 of the operation display device 1. Fig. 4 is a diagram for explaining a procedure by which the operation display device 1 creates an ID list L2 based on the search word list L1.

[0062] First, as shown in FIG. 3, the identification unit 52 determines whether or not page data PD has been read by the display memory 14 in order to display a page in the foreground tab T1 (step S1). Here, the reading of the page data PD by the display memory 14 means reading the page data PD of the foreground tab T1 as screen data. If a tab switching process, which will be described later, is performed before the reading of the page data PD for the foreground tab T1 is completed, the process of displaying a page in the foreground tab T1 will be delayed. Therefore, the display memory 14 first reads the page data PD for the foreground tab T1. Then, in step S1, the identification unit 52 determines that the reading has been performed.

[0063] The page data PD read by the display memory 14 may be data in HTML format, or may be display data constituting a page.

[0064] If the identification unit 52 does not determine that the page data PD has been read in step S1 (NO), the identification unit 52 continues the determination. If the identification unit 52 determines that the page data PD has been read in step S1 (YES), the identification unit 52 prepares to create an ID list L2 based on the search word list L1 (step S2).

[0065] 4, in creating the ID list L2, the identification unit 52 searches the loaded page data PD (HTML file) for search words registered in the search word list L1. In step S2, the identification unit 52 extracts, as a result of the search, links specified by "a href tags" which are tags of anchor links for jumping to pages in the page data PD, and writes them into the ID list L2. At this point, the tab ID of the back tab T2 has not yet been registered in the ID list L2.

[0066] 4, the identification unit 52 extracts three character strings from the URL of the HTML file based on the wildcard "?" for the search word "screen switching SW?". The identification unit 52 registers "page1.html" and "page2.html", which are links included in the extracted character strings, in the ID list L2.

[0067] Next, the identification unit 52 determines whether or not there is an ID list L2 created in a previous page switching process (step S3). If drawing processes have been performed on the back tab T2 several times in the past, an ID list L2 has been created for each drawing process. In this case, the identification unit 52 determines that there is a corresponding ID list L2 (YES). In this case, the drawing unit 53 deletes all back tabs T2 of pages other than the page currently displayed on the foreground tab T1 that exist in the previous ID list L2 but do not exist in the new ID list L2 (step S4). Since the page is not related to the page to be switched, it is preferable to delete the back tab T2 of the page.

[0068] In step S3, the drawing unit 53 compares, for example, the character string of a link (e.g., "page1") registered in the ID list L2 being created with the character string of a link in the ID list L2 that has already been created. If the two character strings do not match, the drawing unit 53 deletes the back tab T2 that corresponds to the corresponding character string in the ID list L2 that has already been created. On the other hand, if the two character strings match, the drawing unit 53 does not delete the back tab T2 that corresponds to the corresponding character string in the ID list L2 that has already been created.

[0069] Then, the drawing unit 53 generates a back tab T2 in the display memory 14 (step S5). Furthermore, the drawing unit 53 requests the Web server unit 7 of the server device 2 for page data PD required for the generated back tab T2 based on the link registered in the ID list L2 (step S6). In step S5, the drawing unit 53A inquires of the specification unit 52 about the page data PD to be read out, and the specification unit 52 specifies the page data PD of the switching candidate based on the link corresponding to the search word in the search word list L1 (specifying step). The drawing unit 53 requests the specified page data PD, acquires the page data PD transmitted from the server device 2 in response to the request, and reads it into the display memory 14 (step S7).

[0070] When the reading of the page data PD is completed, the identification unit 52 registers the tab ID for the generated back tab T2 in the ID list L2 and associates the tab ID with a link (step S8). In this manner, the identification unit 52 proceeds with the creation of the ID list L2.

[0071] Then, the drawing unit 53 draws the page on the back tab T2 based on the acquired page data PD (step S9, drawing step). In drawing the page, the drawing unit 53 obtains a tab ID corresponding to the acquired page data PD from the ID list L2, and draws the page on the back tab T2 of the tab ID.

[0072] Thereafter, the drawing unit 53 judges whether drawing has been performed on the back tabs T2 of all the tab IDs listed in the ID list L2 (step S10). If the drawing unit 53 judges in step S9 that drawing has been performed on the back tabs of all the tab IDs listed in the ID list L2 (YES), the process ends. If the drawing unit 53 does not judge so (NO), the process proceeds to step S6. If the specification unit 52 judges in step S3 that there is no ID list L2 created in the previous page switching process (NO), the process proceeds to step S5. In this way, the drawing unit 53 performs a series of processes of generating a back tab T2 and drawing a page on the back tab T2 for each page.

[0073] Tab switching process Fig. 5 is a flowchart showing the procedure of page switching processing by the browser unit 5. Fig. 6 is a diagram for explaining page switching.

[0074] 5, when a touch operation for switching pages is performed on the touch panel 15, the operation processing unit 54 determines whether or not a tab ID corresponding to the page to be switched and displayed is registered in the ID list (step S11). If the operation processing unit 54 determines in step S11 that the tab ID corresponding to the page is registered in the ID list (YES), it invalidates the touch operation, switches the page of the back tab T2 corresponding to the tab ID to the foreground (step S12), and ends the process.

[0075] Furthermore, if the operation processing unit 54 determines in step S11 that the tab ID corresponding to the page is not registered in the ID list (NO), it switches the page in response to the touch operation (step S13) and ends the process. The operation processing unit 54 requests the server device 2 for page data PD of the file name specified by the link set in the touched object. The operation processing unit 54 displays the page on the display panel 16 based on the page data PD provided by the server device 2 in response to the request.

[0076] As described above, when the identification unit 52 registers a tab ID in the ID list L2 in advance, a flag indicating completion of reading of the page data PD is provided in the ID list L2 by the identification unit 52. In this case, the operation processing unit 54 confirms that the flag is ON and switches the tab, but does not switch the tab if the flag is not ON.

[0077] For example, as shown in FIG. 6, assume that page P is drawn on the foreground tab T1, and pages P1 to P3 (candidate screens for switching) named "Screen A," "Screen B," and "Screen C" are drawn on the back tabs T21 to T23, respectively. Page P includes switches SW1 to SW3 as objects. Switch SW1 is a switch component for switching to "Screen A." Switch SW2 is a switch component for switching to "Screen B." Switch SW3 is a switch component for switching to "Screen C."

[0078] In Fig. 6, for ease of understanding, the rear tabs T1, T21 to T23 are provided with tabs protruding upward. However, in actual use, these tabs may not be displayed.

[0079] Here, when the switch SW1 is touched on page P, if the tab ID corresponding to page P1 is registered in the ID list L2, the operation processing unit 54 switches the back tab T21 to the foreground tab T1. As a result, the back tab T21 becomes the new foreground tab T1.

[0080] Furthermore, when the switch SW1 is touched on page P, if the tab ID corresponding to page P1 is not registered in the ID list L2, the operation processing unit 54 acquires the page data PD of page P1 from the server device 2 in response to the touch operation. The operation processing unit 54 draws the acquired page data PD on the foreground tab T1 as page P1, and displays the drawn page P1 in the effective display area R of the display panel 16.

[0081] Effects of the embodiment The browser unit 5 of the operation display device 1 has an identification unit 52 and a drawing unit 53. The identification unit 52 identifies at least one switch candidate page that can be switched from the page displayed on the foreground tab T1 by a link of an ID list L2 created based on the search words in a search word list L1. The drawing unit 53 draws the identified page on a back tab T2. This allows the switch candidate page to be drawn on the back tab T2 to be selected by setting the search word list L1.

[0082] The identification unit 52 has a function of setting links in the ID list L2. As a result, a link is automatically set each time a page is displayed in the foreground tab T1. Then, switching candidate pages are drawn in the generated back tab T2 based on the page data PD acquired based on the links in the ID list L2. If the search word list L1 is set in advance, switching candidate pages can be prepared in the back tab T2 by the links set based on the search word list L1.

[0083] The identification unit 52 determines whether or not there is an ID list L2 created in a previous page switching process. If an ID list L2 has been created in the past, the drawing unit 53 deletes all back tabs T2 in which pages corresponding to links that exist in the previous ID list L2 but do not exist in the new ID list L2 are drawn, other than the page currently displayed in the foreground tab T1.

[0084] This deletes the back tab T2 of the page that is not related to the page to be switched to. This makes it possible to prevent the unnecessary back tab T2 from reducing the capacity of the display memory 14. This allows the display memory 14 to be used effectively.

[0085] The drawing unit 53 does not draw the switching candidate page when a predetermined condition is satisfied, and draws the switching candidate page when the predetermined condition is not satisfied. In this way, if a predetermined condition is set in advance in cases where drawing would cause inconvenience, the inconvenience can be avoided. As the predetermined condition, various conditions can be set as described above. Therefore, it is possible to deal with various inconveniences.

[0086] The browser unit 5 of the operation display device 1 has an operation processing unit 54. When a tab ID corresponding to a switching candidate page designated by a touch operation accepted on the touch panel 15 is included in the ID list L2, the operation processing unit 54 switches the back tab T2 on which the switching candidate page is drawn to the foreground tab T1. This allows a desired switching candidate page to be displayed among the selected switching candidate pages by switching it from the back tab T2 to the foreground tab T1.

[0087] The operation display device 1 includes a display panel 16 and a browser unit 5 that controls the display of pages on the display panel 16. This allows a user to select a desired page as a switching candidate page on the operation display device 1, and to switch the currently displayed page to one selected from the selected switching candidate pages. This is also true for an operation display device 1A (see FIG. 7) of a second embodiment described later.

[0088] <Configuration of the Operation Display Device> The browser unit 5 has a high utilization rate of the CPU 11 and the main memory 12. For this reason, when the operation display device 1 is configured as an embedded device, it is desirable to limit the processing of the OS to the operation of the browser unit 5. Therefore, the operation display device 1 as an embedded device functions as a browser-only terminal. This is the same for the second embodiment described later.

[0089] In this embodiment, the HMI control unit 8 is provided in the server device 2, but may be provided in the operation display device 1. However, if the HMI control unit 8 is provided in the operation display device 1, the performance of the operation display device 1 will decrease. For this reason, it is preferable that the HMI control unit 8 is provided in the server device 2, not in the operation display device 1. This also applies to the second embodiment described below.

[0090] [Embodiment 2] A detailed description will be given of the second embodiment of the present invention. Note that in this embodiment, components having the same functions as those in the first embodiment are given the same reference numerals and the description thereof will be omitted.

[0091] Configuration of the Operation Display System Fig. 1 is a block diagram showing a hardware configuration of an operation display system 102 according to embodiment 1. Fig. 7 is a block diagram showing a functional configuration of an operation display system 102 according to embodiment 2.

[0092] 1, the operation display system 102 includes an operation display device 1A, a server device 2, and a control device 3. As shown in FIG. 2, the operation display device 1A has a browser unit 5A instead of the browser unit 5 of the operation display device 1 in the operation display system 101 of the first embodiment, and also has a resource management unit 6.

[0093] The browser unit 5A has a setting unit 51 and an operation processing unit 54 like the browser unit 5, but has a specification unit 52A and a drawing unit 53A instead of the specification unit 52 and the drawing unit 53 of the browser unit 5. Furthermore, in the search word list L1 managed by the setting unit 51, a priority may be assigned to each search word. The operation display device 1A functions as a display control device that controls the display panel 16 by including the browser unit 5A.

[0094] The identification unit 52A has the same functions as the identification unit 52, and in addition, manages the display history H. The display history H is a history of the display of pages in the foreground tab T1. For example, the identification unit 52A creates the display history H by associating the link of the page data PD of the page, obtained from the ID list L2, with the date of display of the page. The identification unit 52A assigns a higher priority to the file names registered in the ID list L2 in descending order of date from the display history H during a predetermined period. Alternatively, the identification unit 52A assigns a priority to the file names registered in the ID list L2 according to the priority assigned to each search word in the search word list L1.

[0095] The resource management section 6 manages the ever-changing usage status of the display memory 14 for each process being executed on the operation display device 1A as the used capacity of the display memory 14. The resource management section 6 is provided as a function of the OS.

[0096] A shared memory configuration such as UMA (Unified Memory Architecture), which uses a part of the main memory 12 as the display memory 14, may be applied to the operation display device 1. In such a configuration, when the usage capacity of the display memory area constituting the display memory 14 in the main memory 12 increases, the capacity of the main memory 12 used by the CPU 11 to execute application programs, etc. becomes insufficient. In this case, the resource management unit 6 manages the usage capacity of the display memory area in the main memory 12.

[0097] The drawing unit 53A draws the switching candidate pages on the back tab T2 in descending order of priority. For example, the drawing unit 53A draws the switching candidate pages on the back tab T2 in descending order of priority assigned to each of the switching candidate pages based on the display history H. Alternatively, the drawing unit 53A draws the switching candidate pages on the back tab T2 in descending order of priority assigned to each of the search words in the search word list L1.

[0098] Drawing unit 53A monitors the usage capacity of display memory 14 used for displaying pages on foreground tab T1 and for displaying switching candidate pages on back tab T2, which are managed by resource management unit 6. When the usage capacity of display memory 14 exceeds a predetermined upper limit, drawing unit 53A does not draw switching candidate pages (links) in ID list L2 whose priority level is lower than a predetermined priority level.

[0099] The priority level is, for example, the highest priority of the switching candidate page listed at the top of the ID list L2, and the priority level decreases in descending order. The method of assigning priority levels is not limited to this example.

[0100] When the capacity of the display memory 14 used exceeds a predetermined upper limit, the drawing unit 53A deletes the back tab T2 in which a switching candidate page that exists in the past ID list L2 but does not exist in the latest ID list L2 is drawn. Also, when the capacity of the display memory 14 used is equal to or less than the upper limit, the drawing unit 53A does not delete the back tab T2 in which a switching candidate page is drawn. The capacity of the display memory 14 used here is the capacity of the main memory 12 used for displaying a page in the foreground tab T1 and for displaying a switching candidate page in the back tab T2.

[0101] <Drawing on the back tab> Fig. 8 is a flowchart showing a procedure (display control method) of a process in which the browser unit 5A of the operation display device 1A draws in advance switching candidate pages that may be displayed on the back tab T2. Fig. 9 is a diagram for explaining a procedure in which the operation display device 1A creates an ID list L2 based on the search word list L1.

[0102] First, as shown in FIG. 8, in steps S21 and S22, the determination unit 52A performs the same processes as steps S1 and S2 performed by the determination unit 52 shown in FIG.

[0103] Next, the identification unit 52A determines whether or not the page registered in the ID list L2 is in the display history H (step S23). If the identification unit 52A determines in step S23 that the page registered in the ID list L2 is in the display history H (YES), it rearranges the ranking of the page in the ID list L2 in order of most recent date (step S24). In the process of step S24, the identification unit 52A determines that the page has a higher priority the more recently it was displayed in the display history H, and rearranges the ranking of the file names in the ID list L2 in order of most recent date. In the ID list L2, file names with more recent dates are positioned higher.

[0104] Next, the drawing unit 53A generates back tabs T2 in the display memory 14 in descending order of priority assigned to each of the links (switching candidate pages) in the ID list L2 (step S25). Furthermore, the drawing unit 53A requests the Web server unit 7 of the server device 2 for page data PD required for the generated back tabs T2 based on the links registered in the ID list L2 (step S26). In response to the request, the drawing unit 53A obtains the page data PD transmitted from the server device 2 and reads it into the display memory 14 (step S27).

[0105] When the reading of the page data PD is completed, the identification unit 52A registers the tab ID for the generated back tab T2 in the ID list L2 and associates the tab ID with a link (step S28). In this manner, the drawing unit 53A proceeds with the creation of the ID list L2. The drawing unit 53A draws a page on the back tab T2 based on the acquired page data PD (step S29). As a result, the pages are drawn in order of priority.

[0106] Then, the drawing unit 53A judges whether all the switching candidate pages have been created in the back tab T2 (step S30). If the drawing unit 53A judges in step S30 that all the switching candidate pages have not been created in the back tab T2 (NO), the drawing unit 53A judges whether the usage capacity of the display memory 14 has exceeded the upper limit (step S31). If the drawing unit 53A judges in step S30 that all the switching candidate pages have been created in the back tab T2 (YES), the drawing unit 53A ends the process. If the drawing unit 53A judges in step S31 that the usage capacity of the display memory 14 has exceeded the upper limit (YES), the drawing unit 53A ends the process and stops drawing.

[0107] If the drawing unit 53A determines in step S31 that the capacity of the display memory 14 in use has exceeded the upper limit (YES), the drawing unit 53A may delete the back tabs T2 of old pages that do not exist in the ID list L2 with reference to the ID list L2. In this case, unless the drawing unit 53A determines that the capacity of the display memory 14 in use has exceeded the upper limit, the drawing unit 53A does not delete the back tabs T2 of old pages that do not exist in the ID list L2.

[0108] If the specification unit 52A determines in step S23 that the page registered in the ID list L2 is not in the display history H (NO), the process proceeds to step S25. If the drawing unit 53A determines in step S31 that the usage capacity of the display memory 14 has not exceeded the upper limit (NO), the process proceeds to step S25, and performs a series of processes of generating a back tab T2 with the next highest priority and drawing the page on the back tab T2. In this way, the drawing unit 53A performs a series of processes for each page, of generating back tabs T2 in descending order of priority, drawing the page on the back tab T2, and then determining whether the usage capacity of the display memory 14 has exceeded the upper limit.

[0109] In the above process, the specification unit 52A may change the order of pages in the ID list L2 in accordance with the priority of the search words in the search word list L1, instead of the processes in steps S23 and S24.

[0110] For example, as shown in Fig. 9, assume that the priority of search words registered in the search word list L1 is set in the order of "History display SW03", "Graph display SW??", and "Screen switching SW?". In creating the ID list L2, the identification unit 52A creates the ID list L2 by the same process as the identification unit 52 creates the ID list L2 in the first embodiment. However, after associating the file names with the tab IDs of the back tabs T2, the identification unit 52A rearranges the order of the file names according to the priority of the search words.

[0111] In the example shown in FIG. 9, the identification unit 52A associates the file names with the tab IDs in the search order of HTML files, i.e., the file names "page1.html", "page1.htm2", "page1.htm4", and "page1.htm5". When the association is completed, the identification unit 52A rearranges the order of the file names in the ID list L2 according to the priority of the search words, as shown in FIG. 9. Specifically, the identification unit 52A rearranges the order of the file names in the order of the file names "page1.htm5", "page1.htm4", "page1.htm1", and "page1.htm2".

[0112] Effects of the embodiment The browser section 5A of the operation display device 1A has a specification section 52A and a drawing section 53A. The drawing section 53A draws the switching candidate pages on the back tab T2 in the order of the priority given to each of the screen specific pages. By giving a priority to each of the screen specific pages in advance, the switching candidate pages are drawn in the order of the priority. Therefore, when drawing a large number of switching candidate pages, even if the drawing of the switching candidate pages has to be interrupted due to an increase in the capacity used by the display memory 14, the possibility of drawing the switching candidate pages with high priority can be increased.

[0113] The drawing unit 53A draws the switching candidate pages in the order of the priority assigned to each of the switching candidate pages in the ID list L2, and compares the capacity of the display memory 14 used with a predetermined upper limit each time a switching candidate page is drawn. If the capacity of the display memory 14 used exceeds the predetermined upper limit, the drawing unit 53A stops drawing the switching candidate page. This makes it possible to reduce the capacity of the display memory 14 used when the switching candidate page is drawn. Therefore, the display memory 14 can be used effectively.

[0114] When the capacity of the display memory 14 used exceeds a predetermined upper limit, the drawing unit 53A deletes the second page area in which a switching candidate page that exists in the past ID list L2 but does not exist in the latest ID list L2 is drawn. On the other hand, when the capacity of the display memory 14 used is equal to or less than the upper limit, the drawing unit 53A does not delete the back tab T2 in which the switching candidate page is drawn. As a result, when the capacity of the display memory 14 used exceeds the upper limit, the back tab T2 drawn in the past that is no longer necessary is deleted. This makes it possible to reduce the capacity of the display memory 14 used. Therefore, the capacity of the display memory 14 used can be effectively used.

[0115] [Software implementation example] The functions of the operation display device 1, 1A (hereinafter simply referred to as the device) can be realized by a program for operating the device and for making the device function as each unit included in the browser unit 5, 5A. For this reason, the device has at least one CPU 11 and at least one main memory 12 as hardware for executing the above programs. By executing the above programs with the CPU 11 and the main memory 12, each function described in each of the above embodiments is realized.

[0116] The program may be non-transitory and may be recorded in one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be provided to the device via any wired or wireless transmission medium.

[0117] Also, a part or the whole of the browser units 5, 5A can be realized by a logic circuit. For example, an integrated circuit in which a logic circuit that functions as the browser units 5, 5A is formed is also included in the scope of the present invention.

[0118] 〔summary〕 A display control device according to aspect 1 of the present invention includes a control unit that controls a display device to display a screen in a first page area, which is the foreground page area, using a browser function, and the control unit includes an identification unit that identifies at least one switching candidate screen, which is a screen that can be switched to from the screen displayed in the first page area, using screen identification information that identifies the switching candidate screen, and a drawing unit that draws the switching candidate screen identified by the identification unit in a second page area, which is provided as at least one page area behind the first page area.

[0119] According to the above configuration, the switching candidate screen is specified by the screen specification information, which makes it possible to select the switching candidate screen to be drawn in the second page area.

[0120] A display control device according to aspect 2 of the present invention may be such that, in aspect 1, when the identification unit displays a screen in the first page area, the identification unit sets acquisition information for acquiring the switching candidate screen based on the screen identification information, and the drawing unit draws the switching candidate screen acquired based on the acquisition information in the second page area.

[0121] According to the above configuration, the acquired information is automatically set every time a screen is displayed in the first page area, and a switching candidate screen acquired based on the acquired information is drawn in the second page area. This allows a switching candidate screen to be prepared in the second page area by setting the acquired information in advance.

[0122] A display control device according to aspect 3 of the present invention is in aspect 1 or 2, and the drawing unit may draw the switching candidate screens in the second page area in descending order of priority. For example, the drawing unit may draw the switching candidate screens in the second page area in descending order of priority assigned to each of the switching candidate screens based on a display history of screens that have been displayed in the first page area in the past. Alternatively, the drawing unit may draw the switching candidate screens in the second page area in descending order of priority assigned to each of the screen specification information.

[0123] According to the above configuration, for example, a screen that is frequently displayed based on the display history can be preferentially displayed in the second page area. Also, by assigning a priority to each piece of screen specification information in advance, switching candidate screens are drawn in descending order of priority. This increases the possibility of drawing a switching candidate screen with a high priority even if the drawing of the switching candidate screens must be interrupted due to an increase in memory usage when drawing a large number of switching candidate screens.

[0124] A display control device according to aspect 4 of the present invention, in accordance with aspect 2, may further include a memory used for drawing the switching candidate screens in the second page area, wherein the identification unit creates a list of acquired information corresponding to the switching candidate screens, and the drawing unit draws the switching candidate screens in order of the priority assigned to each of the switching candidate screens in the list, and compares the memory usage with a predetermined upper limit value each time one of the switching candidate screens is drawn, and stops drawing when the memory usage exceeds the upper limit value.

[0125] According to the above configuration, when the memory usage exceeds the upper limit, the drawing of the switching candidate screen is stopped. This makes it possible to reduce the memory usage when the switching candidate screen is drawn. Therefore, the memory can be used efficiently.

[0126] A display control device according to aspect 5 of the present invention, in accordance with aspect 2, further includes a memory used to draw the switching candidate screen in the second page area, wherein the identification unit creates a list of acquired information corresponding to the switching candidate screen, and when the memory usage exceeds a predetermined upper limit value, the drawing unit deletes the second page area in which the switching candidate screen corresponding to the acquired information that is present in the past list but not in the latest list is drawn, whereas when the memory usage is equal to or less than the upper limit value, the drawing unit does not need to delete the second page area in which the switching candidate screen is drawn.

[0127] According to the above configuration, when the memory usage exceeds the upper limit, the second page area that was previously drawn and is no longer needed is deleted. This makes it possible to reduce the memory usage. Therefore, the memory can be used effectively.

[0128] A display control device according to aspect 6 of the present invention may be such that, in aspect 2, the identification unit creates a list of acquired information corresponding to the switching candidate screen and determines whether or not there is a previously created list, and if it is determined that there is a previously created list, the drawing unit compares the acquired information of the previously created list and the newly created list, and deletes the second page area in which the switching candidate screen identified by the acquired information that is present in the previously created list but not in the newly created list is drawn.

[0129] According to the above configuration, the second page area in which the switching candidate screen that is not related to the screen to be switched is drawn is deleted. Therefore, it is possible to prevent the unnecessary second page area from reducing the memory capacity for displaying the second page area. Therefore, the memory can be effectively utilized.

[0130] A display control device according to aspect 7 of the present invention may, in any of aspects 1 to 6, not draw the switching candidate screen if a specified condition is satisfied, and may draw the switching candidate screen if the specified condition is not satisfied.

[0131] According to the above configuration, if a predetermined condition is set in advance in cases where performing drawing would cause inconvenience, the inconvenience can be avoided.

[0132] A display control device according to aspect 8 of the present invention, in any of aspects 1 to 7, may further include an operation unit that accepts an operation to designate the switching candidate screen, wherein the identification unit creates a list of acquired information corresponding to the switching candidate screen, and the control unit may have a switching unit that switches the second page area in which the switching candidate screen is drawn with the first page area when area identification information corresponding to the switching candidate screen designated by the operation accepted by the operation unit is included in the list.

[0133] According to the above configuration, it is possible to switch a desired switching candidate screen from the selected switching candidate screens to the first page area and display the selected switching candidate screen.

[0134] An operation display device according to a ninth aspect of the present invention includes the display control device according to the eighth aspect and a display device controlled by the display control device.

[0135] According to the above configuration, in the operation display device, a desired screen can be selected as a switching candidate screen, and one selected from the selected switching candidate screens can be used to switch the currently displayed screen.

[0136] A display control method according to aspect 10 of the present invention is a display control method for controlling a display device to display a screen in a first page area, which is the foreground page area, using a browser function, and includes an identification step of identifying at least one switching candidate screen, which is a screen that can be switched to from the screen displayed in the first page area, using screen identification information that identifies the switching candidate screen, and a drawing step of drawing the switching candidate screen identified by the identification step in a second page area, which is provided as at least one page area behind the first page area.

[0137] According to the above method, like the display control device according to the first aspect, it is possible to select a switching candidate screen to be drawn in the second page area.

[0138] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. In addition, embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0139] 1,1A Operation display device (display control device) 5 Browser section (control section) 14 Display memory (memory) 15 Touch panel (operation section) 16 Display panel (display device) 52,52A Specific part 53,53A Drawing section 54, 54A Operation processing section (switching section) L1 Search word list (screen specific information) L2 ID List (List) P1~P3 pages (switching candidate screens) T1 Frontmost tab (first page area) T2, T21~T23 Back tab (second page area)

Claims

1. a control unit that controls the display device to display a screen in a first page area, which is a foreground page area, by a browser function; The control unit is a specifying unit that specifies at least one switching candidate screen, which is a screen that can be switched from the screen displayed in the first page area, by screen specification information that specifies the switching candidate screen; A display control device comprising: a drawing unit that draws the switching candidate screen identified by the identification unit in a second page area, at least one of which is provided as the page area behind the first page area.

2. the specifying unit sets acquisition information for acquiring the switching candidate screen based on the screen specifying information when a screen is to be displayed in the first page area; The display control device according to claim 1 , wherein the drawing unit draws the switching candidate screen acquired from the acquired information in the second page area.

3. The display control device according to claim 1 , wherein the drawing unit draws the switching candidate screens in the second page area in descending order of priority.

4. Further, a memory used for drawing the switching candidate screen in the second page area, The identification unit creates a list of acquired information corresponding to the switching candidate screen, 3. The display control device according to claim 2, wherein the drawing unit draws the switching candidate screens in order of the priority assigned to each of the acquired information in the list, compares the memory usage capacity with a predetermined upper limit value each time one of the switching candidate screens is drawn, and stops drawing when the memory usage capacity exceeds the upper limit value.

5. Further, a memory used for drawing the switching candidate screen in the second page area, The identification unit creates a list of acquired information corresponding to the switching candidate screen, 3. The display control device according to claim 2, wherein the drawing unit deletes the second page area in which the switching candidate screen corresponding to the acquired information that exists in the past list but does not exist in the latest list when the memory usage capacity exceeds a predetermined upper limit value, whereas the drawing unit does not delete the second page area in which the switching candidate screen is drawn when the memory usage capacity is equal to or less than the upper limit value.

6. The identification unit creates a list of acquired information corresponding to the switching candidate screen, and determines whether or not the list has been created previously; 3. The display control device according to claim 2, wherein when it is determined that a previously created list exists, the drawing unit compares the acquired information of the previously created list and the newly created list, and deletes the second page area in which the switching candidate screen identified by the acquired information that exists in the previously created list but does not exist in the newly created list is drawn.

7. The display control device according to claim 1 , wherein the drawing unit does not draw the switching candidate screen when a predetermined condition is satisfied, and draws the switching candidate screen when the predetermined condition is not satisfied.

8. An operation unit that accepts an operation to specify the switching candidate screen is further provided, The identification unit creates a list of acquired information corresponding to the switching candidate screen, 8. The display control device according to claim 1, wherein the control unit has a switching unit that switches the second page area in which the switching candidate screen is drawn with the first page area when area identification information corresponding to the switching candidate screen specified by an operation accepted by the operation unit is included in the list.

9. A display control device according to claim 8 ; An operation display device comprising: a display device controlled by the display control device.

10. A display control method for controlling a display device to display a screen in a first page area, which is a foreground page area, by a browser function, comprising: a specifying step of specifying at least one switching candidate screen, which is a screen that can be switched from the screen displayed in the first page area, by screen specifying information that specifies the switching candidate screen; A display control method including a drawing step of drawing the switching candidate screen identified by the identification step in a second page area, at least one of which is provided as the page area behind the first page area.

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