JP7149826B2 - screen display device - Google Patents

Description

The present invention relates to a screen display device that controls rendering of a screen containing objects.

A display device such as an HMI (Human Machine Interface) device such as a programmable display displays a screen that includes objects and is created in a specific format. In such a display device, if there are few objects that change when updating the screen display, only the objects that change are displayed instead of drawing the entire screen in order to shorten the drawing time of the screen. Perform partial drawing to draw.

For example, Patent Literature 1 describes an information device that reduces the overall drawing time by switching between normal drawing and reuse of drawing data. This information device determines whether or not to reuse drawing data depending on whether or not the reuse rate of drawing data is greater than a threshold value for determining whether or not the drawing data can be reused.

Japanese Patent Application Laid-Open No. 2013-218478 (published on October 24, 2013)

In general, it is rare for all objects to change in the screen display update, so drawing time can be shortened by partial drawing rather than by whole drawing. However, when many objects change at the same time or when many objects overlap, the overall drawing may shorten the drawing time rather than the partial drawing.

On the other hand, in the information device disclosed in Patent Document 1, since the threshold value is a fixed value, it may not be possible to appropriately determine whether drawing data can be reused depending on how the object changes. . As a result, although the drawing data is reused, the drawing time becomes longer than when the drawing data is not reused (whole drawing).

An object of one embodiment of the present invention is to efficiently determine whether to perform full screen drawing or partial screen drawing when updating the display of the screen.

In order to solve the above problems, a screen display device according to an aspect of the present invention is a screen display device that displays a screen including at least one object, the screen display device comprising: a whole drawing that draws the entire screen; a drawing unit that predicts, based on a reference value, which of the partial drawings for drawing the changing object on the screen can update the screen faster, and draws the screen with the predicted whole drawing or the partial drawing; At least a reference value update unit for updating the reference value according to the length of the partial drawing time required for the partial drawing relative to the overall drawing time required for the entire drawing.

According to the above configuration, the reference value is updated according to the length of the partial drawing time with respect to the entire drawing time, so the reference value can be approximated to an appropriate value. As a result, when the partial drawing time is longer than the overall drawing time even though the partial drawing has been performed, the reference value can be changed to increase the probability of performing the overall drawing.

In the screen display device, each of the objects has a unique eigenvalue, the reference value is set in advance as an arbitrary ratio to a sum of the eigenvalues of all the objects on the screen, and the rendering The unit draws the whole when a total value obtained by totaling the eigenvalues of the changing object on the screen is equal to or greater than the reference value, and draws the part when the total value is less than the reference value. and the reference value updating unit updates the reference value so as to decrease when the partial drawing time exceeds the overall drawing time, and updates the reference value when the partial drawing time is equal to or less than the overall drawing time. or maintain the reference value.

According to the above configuration, when the partial drawing time is longer than the total drawing time even though the partial drawing has been performed, the reference value can be lowered to appropriately adjust the drawing time. Also, when the partial drawing time is shorter than the total drawing time, the reference value can be raised to perform appropriate adjustment.

In the screen display device, the reference value update unit updates the reference value to the total drawing time when a partial drawing average time, which is an average of the times required for the partial drawing of a specified number of times, exceeds the overall drawing time. updating so as to decrease according to the ratio of the partial drawing average time, and when the partial drawing average time is equal to or less than the overall drawing time, the average drawing per one of the objects drawn by the partial drawing of the specified number of times A predicted partial drawing time required for the partial drawing predicted for the screen is calculated by multiplying the time by the reference value, and when the predicted partial drawing time is less than the overall drawing time, the reference value is applied to the overall drawing. The reference value is maintained when the predicted partial drawing time is greater than or equal to the total drawing time, and is updated according to the ratio of the predicted partial drawing time to the time.

According to the above configuration, the time required for partial drawing performed the prescribed number of times is averaged as the average partial drawing time. As a result, even if, for example, only one partial drawing out of the prescribed number of partial drawings is outstanding and takes a long time, the partial drawing average time mitigates the effect. Then, a decision to update the reference value is made by comparing the partial drawing average time with the overall drawing time. Therefore, it is possible to suppress erroneous updating of the reference value due to a large change in the partial drawing time that may occur suddenly. Also, it selects whether to increase the reference value or maintain the reference value according to the ratio of the predicted partial drawing time to the entire drawing time. By selecting whether to raise or maintain the reference value in this way, unnecessary updating of the reference value can be avoided, and the reference value can be brought closer to the optimum value more quickly.

In the screen display device, each of the objects has a unique eigenvalue, and the drawing unit performs the overall drawing when the display of the screen is switched, and the first display of the switched display of the screen. The partial drawing is performed at the time of drawing update, and the reference value updating unit registers the entire drawing time and the partial drawing time, and updates the characteristic value of the object drawn at the first drawing update of the switched display screen. is totaled on the screen as the reference value, and the rendering unit sets the object to be changed when the partial rendering time is less than the total rendering time at the second or later rendering update. is in a first state in which a total value obtained by aggregating the eigenvalues of is equal to or less than the reference value on the screen, when the partial drawing time is less than the entire drawing time, and the total value exceeds the reference value In the second state, or in the third state where the partial drawing time is equal to or longer than the total drawing time and the total value is equal to or less than the reference value, the partial drawing is performed and the partial drawing is performed. When the drawing time is equal to or longer than the overall drawing time, and when the total value exceeds the reference value and is in a fourth state, the reference value update unit performs the overall drawing, and the reference value update unit updates the drawing for the second time or later. , when the actual drawing time required for the partial drawing in the first state is equal to or longer than the overall drawing time, when the actual drawing time in the second state is less than the overall drawing time, or in the third state when the partial drawing time is updated to the actual drawing time and the reference value is updated to the total sum value, and when the actual drawing time in the second state is equal to or greater than the overall drawing time, the reference value is updated to the average value of the total sum value and the reference value, and the partial drawing time is updated to the average value of the actual drawing time and the partial drawing time, and in the fourth state, the overall drawing The time is updated to the overall drawing time required for the newly performed overall drawing.

According to the above configuration, the reference value is set to the initial total value obtained by the partial drawing at the time of the first drawing update, so there is no need to set the reference value in advance.

In the screen display device, the eigenvalue is the number of units.

According to the above configuration, the reference value is defined by the number of objects that can be easily obtained. This can simplify the calculations for obtaining the reference.

In the screen display device, the eigenvalue is the ratio of the area of the object to the total area of the screen.

According to the above configuration, even if there is a difference in size between objects included in the screen, it is possible to more appropriately determine which of the entire drawing and the partial drawing is to be performed.

In the screen display device, the eigenvalue is a weight given according to the characteristics of the object.

According to the above configuration, even if there is a difference in weight between objects included in the screen, it is possible to more appropriately determine whether to perform full drawing or partial drawing.

In the screen display device, when performing the partial drawing, the drawing unit indicates that the plurality of objects overlap on the screen, and indicates that the plurality of objects overlap, which is set for each screen. A plurality of overlapping objects are drawn when at least one of the plurality of objects changes based on overlap information.

According to the above configuration, it is possible to determine the overlapping of objects based on the overlapping information, and draw the overlapping objects efficiently.

In the screen display device, the drawing unit determines the drawing order in which drawing is most efficiently performed when there are a plurality of drawing orders for drawing the plurality of overlapping objects, and determines the drawing order for drawing the plurality of overlapping objects according to the drawing order. Draw the object.

According to the above configuration, it is possible to shorten the screen update time by selecting an order that allows drawing to be performed in a shorter time.

In the screen display device, the reference value is set for each screen.

According to the above configuration, there is no need to optimize the reference value again when the screen is switched. Therefore, the time required for the reference value to reach the optimum value can be shortened.

According to one aspect of the present invention, it is possible to efficiently determine whether to perform full screen drawing or partial screen drawing when updating the screen display.

1 is a block diagram showing the configuration of a control system according to each embodiment of the present invention; FIG. It is a block diagram which shows the system configuration|structure of the said programmable display. It is a flowchart which shows the display update processing procedure of a screen by the said programmable display. It is a flow chart which shows a processing procedure at the time of screen change by the above-mentioned programmable indicator. 5A and 5B are diagrams showing examples of switched screens referred to in the description of the flowchart of FIG. 4; FIG. 5 is a diagram showing object information and object overlap information listed by the processing in the flowchart of FIG. 4; FIG. It is a flow chart which shows a processing procedure of reference value update by the above-mentioned programmable indicator. 8 is a graph showing the relationship between the time ratio and the coefficient used in the first calculation method used in the processing in the flowchart of FIG. 7; 8 is a graph showing the relationship between the time ratio and the coefficient used in the second calculation method used in the processing in the flowchart of FIG. 7; It is a flowchart which shows the processing procedure of another reference value update by the said programmable display. (a) and (b) are diagrams showing the relationship between the object and the rectangle defining the area when the reference value is defined by the area of the object. FIG. 10 is a diagram showing an example of the ratio of each object to the area of the entire screen, which is used for updating the reference value when the reference value is the area of the object;

[Embodiment 1]
The first embodiment of the present invention will be described below with reference to FIGS. 1 to 9. FIG.

First, the control system according to this embodiment will be described.

FIG. 1 is a block diagram showing the configuration of a control system according to this embodiment. FIG. 2 is a block diagram showing the configuration of the essential parts of the programmable display 1. As shown in FIG.

The programmable display 1 (screen display device) is a built-in device with a dedicated OS (Operating System) installed, and has a function of executing an HMI program for realizing various functions of the programmable display 1 . The programmable display 1 is an HMI device with improved dust resistance, drip resistance, vibration resistance, etc., so as to be suitable for harsh environments such as factories.

The HMI program is a program that realizes various functions such as communication with an external device, display of data acquired from the external device, and reception of operations by an operator using an input device.

First, the hardware configuration of the programmable display 1 will be described.

As shown in FIG. 1, the programmable display device 1 includes a CPU (Central Processing Unit) 11, a main memory 12, a ROM (Read Only Memory) 13, a user memory 14, a touch panel 15, and a display panel 16 ( display unit) and an interface unit 17 .

The CPU 11 is a processing device that executes HMI programs. Specifically, when executing the HMI program, the CPU 11 receives data from the main memory 12, the user memory 14, the touch panel 15, etc., and stores the results of computation or processing on the data in the main memory 12, the user memory, or the like. 14, output to the display panel 16 or the like.

The main memory 12 is a memory that constitutes the main storage device in the programmable display device 1, and is composed of a DRAM (Dynamic Random Access Memory).

The ROM 13 stores programs essential for the operation of the programmable display 1, such as BIOS (Basic Input Output System) executed when the programmable display 1 is activated or reset.

The user memory 14 is a large-capacity storage device that stores data created by the user, for example, main screen data for displaying an HMI screen, which will be described later. The user memory 14 is composed of FEPROM (Flash Erasable and Programmable ROM) or the like.

The touch panel 15 is arranged on the display panel 16, receives a touch operation on the screen displayed on the display panel 16, and outputs a touch operation signal as an input signal.

The display panel 16 displays an HMI screen based on main screen data stored in the user memory 14 . As the display panel 16, a flat display panel such as a liquid crystal display panel is used.

The interface unit 17 includes a connection unit for communicably connecting with the control device 2 and a connection unit for communicably connecting with the PC (personal computer) 4 . The interface unit 17 is equipped with various interfaces such as a serial interface, LAN (Local Area Network), and USB (Universal Serial Bus).

The control device 2 is an external device such as a PLC (Programmable Logic Controller), a temperature controller, an inverter, etc., and has a function of communicating with the programmable display 1 . The control device 2 exchanges data with the device 20 . Input devices such as sensors and switches, and output devices such as actuators, relays, solenoid valves, and indicators are used as the devices 20 .

Next, the system configuration of the programmable display 1 will be explained.

As shown in FIG. 2, the programmable display 1 includes an HMI control section 3 as a portion having control functions.

The HMI control unit 3 is a part having an HMI function realized by executing the HMI program by the CPU 11 .

Here, the HMI function is to generate an instruction to the control device 2 according to the user's input operation, acquire various data from the control device 2, display the acquired various data, and accept the input operation. It is a function including display of an HMI screen for performing. The HMI control unit 3 includes, as HMI functions, an operation control unit 31 that controls each unit based on user operation input and changes in data held by the control device 2, and a display control unit 32 that controls display of HMI images. have.

The HMI screen is a screen including various objects for displaying the status of the device 20 connected to the control device 2 and accepting operations on the touch panel 15 . Various component images such as a lamp image, a data display image, and a switch image are prepared as objects provided on the HMI screen. Various figures (circles, rectangles, polygons, straight lines, etc.) and images can also be used as objects.

Screen data for displaying such an HMI screen are created in the PC 4 and stored in the user memory 14 . The PC 4 has a drawing editing section 41 as a functional block implemented by an application program for creating and editing screens.

The operation control unit 31 generates an operation instruction according to an input operation by a user's touch on the touch panel 15 . The operation instructions include start/stop instructions for the control device 2, change of control data given to the control device 2, screen switching, and the like. Further, the operation control unit 31 generates a control instruction according to changes in the data of the control device 2 . This control instruction includes screen switching and the like.

The display control unit 32 performs control processing for displaying the HMI screen on the display panel 16 based on the screen data. Further, the display control unit 32 performs a process of reflecting the data of the control device 2 acquired via the interface unit 17 on the HMI screen. For example, the display control unit 32 performs processing for turning on/off the above-described lamp image on the HMI screen, and for displaying data on the above-described data display device image. Further, the display control unit 32 performs processing for changing the state of the HMI screen according to the operation instruction. For example, the display control unit 32 receives the operation instruction for operating the switch image, and performs processing for changing the display state (color, shape, etc.) of the switch image. Further, the display control unit 32 performs HMI screen switching processing in accordance with the user's operation.

In addition, the display control unit 32 has a drawing control function that performs either overall drawing for drawing the entire screen or partial drawing for drawing changing objects when updating the display of the screen (HMI screen). ing. The display control unit 32 has a drawing unit 331, a drawing time measuring unit 332, and a reference value updating unit 333 in order to realize this drawing control function.

The drawing unit 331 causes the display panel to display based on the screen data stored in the user memory 14 . Specifically, the drawing unit 331 temporarily develops the screen data in a video memory (not shown) and transfers it to the display panel 16 in units of pixels. The video memory may be allocated to a partial storage area of the main memory 12, or may be separately provided as a VRAM (Video RAM).

The drawing unit 331 also predicts which of the whole drawing and the partial drawing can update the screen faster based on the reference value, and draws the screen in the video memory with the predicted whole drawing or partial drawing.

The reference value is a reference value used by the reference value updating unit 333, which will be described later, to determine whether to perform the entire drawing or the partial drawing when updating the display of the screen. In this embodiment, the reference value is defined by the number of objects (the number of objects). Also, in this embodiment, each object is assumed to have the number of units "1" as its unique eigenvalue. The specification of the reference value will be referred to in the description of the first method and the second method, which will be described later.

The drawing time measurement unit 332 measures the drawing execution time (drawing time) performed by the drawing unit 331 . Specifically, the drawing time measurement unit 332 measures the time from receiving a notification that drawing has started from the drawing unit 331 to receiving a notification that drawing has ended from the drawing unit 331 . The drawing time measurement unit 332 stores the measured drawing time in the main memory 12 .

The reference value update unit 333 updates the reference value by adjusting it based on the drawing time measured by the drawing time measurement unit 332 . Specifically, the reference value updating unit 333 updates the reference value according to at least the length of the partial drawing time required for the partial drawing by the drawing unit 331 relative to the overall drawing time required by the drawing unit 331 for the entire drawing. .

The update of the reference value by the reference value updating unit 333 will be described later in detail.

Next, the operation of drawing by the programmable display device 1 will be described. FIG. 3 is a flow chart showing a processing procedure for updating the screen display by the programmable display device 1. As shown in FIG.

As shown in FIG. 3, in the programmable display device 1, when the screen is displayed for the first time, the drawing unit 331 sets the drawing mode to full drawing (step S1), and displays the screen in the screen mode, that is, the whole drawing. Draw (step S2).

Next, the drawing unit 331 determines whether or not the screen needs to be updated due to some change in the object (step S3). The drawing unit 331 continues waiting until the screen needs to be updated (NO in step S3). When the drawing unit 331 determines that the screen needs to be updated (YES in step S3), it determines whether the number of objects that must be updated on the screen is equal to or greater than a reference value (step S4).

If the rendering unit 331 determines in step S4 that the number of objects to be updated (the total value of the eigenvalues “1”) is not equal to or greater than the reference value (NO), the objects to be updated on the screen overlap. It is determined whether or not there are only objects that do not exist (step S5).

When the drawing unit 331 determines in step S4 that the number of objects to be updated is equal to or greater than the reference value (YES), it sets the drawing mode to full drawing (step S6), and returns the process to step S2.

When the drawing unit 331 determines in step S5 that only non-overlapping objects are to be updated (YES), the drawing unit 331 sets the drawing mode to partial drawing in which overlap search is not performed (step S7). is returned to step S2. Further, when the drawing unit 331 determines in step S5 that the object to be updated includes an overlapping object (NO), the drawing unit 331 sets the drawing mode to partial drawing for overlapping search (step S8). is returned to step S2.

Now, the above overlap search will be described. FIG. 4 is a flow chart showing a processing procedure when switching screens by the programmable display device 1 . FIG. 5 is a diagram showing an example of the switched screen 100 referred to in the description of the flowchart of FIG. FIG. 6 is a diagram showing object information and object overlapping information listed by the processing in the flowchart of FIG.

As shown in FIG. 4, first, when screen switching occurs in response to an operation on the touch panel 15, the drawing unit 331 lists object information included in the switched screen together with object overlapping information generated by the PC 4. (Step S11).

When the screen 100 shown in FIG. 5 is switched and displayed, the object overlap information shown in FIG. 6 is used. The object overlap information is generated by the drawing editing unit 41 of the PC 4 when a plurality of objects are arranged so as to overlap each other when the screen is created. This object overlapping information is transferred from the PC 4 to the programmable display device 1 together with the screen data, and is stored in the user memory 14 together with the screen data.

A screen 100 includes a switch 101, a numerical display 102, and circles 103 and 104 as objects. The switch 101 is an operation component for performing on/off operation, switching operation, and the like. The numerical display 102 is a display component that displays numerical values acquired as data from the control device 2 or the like. Circle 104 is smaller than circle 103 and is superimposed on circle 103 . Circles 103 and 104 are filled with different colors.

The object overlap information for the screen 100 is created in list form, as shown in FIG. In this object overlap information, various objects provided on the screen 100 are assigned ordinal numbers 1, 2, . . . to the object names.

In the overlap search, the drawing unit 331 searches for overlapping objects in the object overlap information created as described above. Then, the drawing unit 331 selects a drawing update order for efficiently updating the display of the overlapping objects. For example, in the case of the circles 103 and 104 (double circles) shown in FIG. 5, the double circle composed of two objects must be redrawn as a whole even if only one changes but the other does not. , so the other must also be drawn.

For example, if only circle 104 changes, only circle 104 is drawn according to the change. Also, when only the circle 103 changes, the order (drawing order) is determined such that after the circle 103 is drawn according to the change, the circle 104 is drawn in the same state as before drawing. On the other hand, when both the circles 103 and 104 are changed, the drawing order differs depending on which one is changed first.

In the first case, circle 104 is changed by changing circle 103 after changing circle 104 . In the first case, after drawing the circle 104, the large circle 103 is drawn on the circle 104, so the circle 104 needs to be drawn on the circle 103 at the end. In the second case, circle 104 is changed after circle 103 is changed. Since the second case is more efficient than the first case, rendering unit 331 selects the order according to the second case to render circles 103 and 104 when both circles 103 and 104 change.

When the drawing unit 331 searches for overlapping objects and finds a plurality of overlapping objects, the drawing unit 331 selects an efficient drawing order according to the change state of these objects, and draws according to the selected order. I do. In this way, by selecting the order in which drawing can be performed in a shorter time, it is possible to shorten the screen update time.

Calculation of the range for drawing overlapping objects requires coordinate calculation and the like, and requires a large amount of arithmetic processing. For this reason, in a device such as a personal computer equipped with a CPU having a high processing capability, the load on the CPU due to the above arithmetic processing is small. However, since a dedicated machine such as the programmable display device 1 is often equipped with a CPU with a low processing capability, the load on the CPU due to the above arithmetic processing is heavy. Therefore, as described above, when there are a plurality of drawing orders for drawing an object, by selecting a drawing order in which the drawing unit 331 can draw efficiently, the amount of the above arithmetic processing can be reduced and the CPU 11 can reduce the burden on

In addition, the rendering unit 331 searches for overlapping objects as described above, even for objects whose overlapping state changes due to changes in position, shape, etc. Select the drawing order and draw according to the selected order.

As for the position, when the objects are moved, they may or may not overlap. As for the shape, when the size of the object changes, there are cases where overlap occurs and cases where overlap does not occur. In these cases, since the overlap cannot be defined when the screen is created, it is necessary to determine the overlap while the programmable display device 1 is actually performing the drawing operation. Therefore, the drawing unit 331 draws the overlapping objects after recognizing their overlapping state before updating the screen.

Subsequently, the updating operation of the reference value by the programmable display device 1 will be explained.

Here, two representative methods for updating the reference value will be described.

First, the first method will be explained. FIG. 7 is a flow chart showing a processing procedure for updating the reference value by the programmable display device 1. As shown in FIG.

In the following description, the time taken by the drawing unit 331 for the entire drawing is taken as the overall drawing time Ta, and the time taken by the drawing unit 331 for the partial drawing is taken as the partial drawing time Tp. The drawing time measurement unit 332 measures the overall drawing time Ta and the partial drawing time Tp each time the drawing unit 331 performs the overall drawing and the partial drawing, and stores them in the main memory 12 .

As shown in FIG. 7, first, in a state where screen drawing is repeatedly performed, the drawing unit 331 determines whether or not partial drawing has occurred n times (predetermined number of times) (step S21). When the drawing unit 331 determines in step S21 that partial drawing has not occurred n times (NO), the process ends.

When the drawing unit 331 determines in step S21 that the partial drawing has occurred n times (YES), the reference value updating unit 333 receives the determination result, and the average of the n partial drawing times Tp equals the total drawing time Ta. It is determined whether or not it has exceeded (step S22). If the reference value updating unit 333 determines in step S22 that the average has exceeded the total drawing time Ta (YES), it updates the reference value using the first calculation method (step S23), and ends the process.

Further, when the reference value updating unit 333 determines in step S22 that the above average is equal to or less than the total drawing time Ta (NO), it further determines whether the predicted partial drawing time Tpp is less than the total drawing time Ta. (step S24).

Here, the average rendering time Tav for one object is calculated by dividing the sum of n partial rendering times Tp (Tp1, Tp2, . . . , Tpn) by the total number N of objects updated n times. (Formula (1) below). Also, the predicted partial drawing time Tpp is calculated by multiplying the average drawing time Tav for one object by the reference value Vr (equation (2) below).

Tav=(Tp1+Tp2+,...,+Tpn)/N...(1)
Tpp=Tav*Vr (2)
When the reference value updating unit 333 determines in step S24 that the predicted partial drawing time Tpp is less than the total drawing time Ta (YES), it updates the reference value by the second calculation method (step S25), and ends the process. . Further, when the reference value updating unit 333 determines in step S24 that the predicted partial drawing time Tpp is equal to or longer than the total drawing time Ta (NO), the processing ends while maintaining the reference value (step S26).

In step S26, the reference value Vr is the value represented by the following formula.

(Vr−1)*Tav<Ta≦Tav*Vr
In this case, there is no need to change the reference value.

Here, the first calculation method and the second calculation method will be described.

FIG. 8 is a graph showing the relationship between the time ratio and the coefficient used in the first calculation method used in the processing in the flowchart of FIG. FIG. 9 is a graph showing the relationship between the time ratio and the coefficient used in the second calculation method used in the processing in the flowchart of FIG.

First, the first calculation method will be explained. The first calculation method is used when lowering the reference value.

In the first calculation method, the reference value is preset as an arbitrary ratio to the total sum of eigenvalues "1" for all objects on the screen (the total number of objects).

When the average partial drawing time Tpav, which is the average of the n partial drawing times Tp, exceeds the total drawing time Ta, the reference value updating unit 333 calculates the ratio Rt1, that is, the average partial drawing time Tpav, by the following equation (3). Comparing with the total drawing time Ta, the proportion of the extra drawing time is calculated. As the value of the ratio Rt1 increases, the rate at which the reference value is lowered increases.

Rt1=(Tpav/Ta)*100-100(%) (3)
The reference value updating unit 333 obtains the coefficient corresponding to the calculated ratio Rt1 from the relationship (graph) shown in FIG. For example, when the average partial drawing time Tpav is 1.5 s and the total drawing time Ta is 1.0 s, the reference value updating unit 333 calculates a ratio Rt1 of 50%, and in the relationship of FIG. 20 is obtained for the coefficient corresponding to %. Note that the horizontal axis of FIG. 8 indicates the ratio of extra drawing time when the average partial drawing time Tpav is compared with the total drawing time Ta.

In the relationship shown in FIG. 8, the longer the extra time taken for drawing, the larger the coefficient. When the percentage of time spent on drawing increases beyond a certain value, the coefficient is not increased. In addition, when the ratio of the extra time taken for drawing becomes smaller than a certain value, the coefficient is not reduced. In FIG. 8, the upper limit of the coefficient is set to 20, and the lower limit of the coefficient is set to 0.

The larger the coefficient, the larger the amount of change in the reference value. However, if the coefficient becomes too large, the amount of change in the reference value will increase, and the coefficient will be affected. Therefore, it takes time to update the reference value to the optimum value. Therefore, an upper limit value and a lower limit value are provided for the coefficient so as not to receive such influence.

The reason why the lower limit value of the coefficient is 0 is that when the average partial drawing time Tpav and the predicted partial drawing time Tpp are not much different from the total drawing time Ta, there is almost no need to change the reference value. This is because it is considered that Also, by changing the lower limit value of the ratio (bringing it closer to 0), it is possible to change the reference value even when there is no difference between these times (when the difference is not 0).

Here, the upper limit value (50) and lower limit value (5) of the ratio in FIG. 8 are an example, and are not limited to these values. Set the upper and lower limits to appropriate values according to the environment. An upper limit and a lower limit are set for the ratio so that the amount of change in the reference value does not become too large due to an accidental extreme change.

Also, the coefficient and the upper and lower limits of the ratio can be set in advance.

Then, the reference value update unit 333 calculates a new reference value Vr _n+1 based on the current reference value Vr _n and the coefficient K based on the following equation (4).

Vr _n+1 =Vr _n *(100−K)/100 (4)
As described above, the first calculation method is used when the number of objects to be updated is less than the reference value, but as a result of partial drawing, it takes longer than the entire drawing. In this case, the reference value is too large and needs to be lowered.

Next, the second calculation method will be explained. The second calculation method is used when raising the reference value.

A reference value is set in advance in the second calculation method as well.

When the average partial drawing time Tpav is equal to or shorter than the total drawing time Ta, the reference value updating unit 333 determines the ratio Rt2 according to the following equation (5), that is, the predicted partial drawing time Tpp is shorter than the total drawing time Ta. Calculate the percentage of time. As the value of the ratio Rt2 increases, the rate at which the reference value is increased increases. The predicted partial drawing time Tpp in Equation (5) is calculated in step S24 described above.

Rt2=100-(Tpp/Ta)*100(%) (5)
The reference value updating unit 333 obtains the coefficient corresponding to the calculated ratio Rt2 from the relationship (graph) shown in FIG. For example, when the predicted partial drawing time Tpp is 1.0 s and the total drawing time Ta is 2.0 s, the reference value updating unit 333 calculates a ratio Rt2 of 50%, and in the relationship of FIG. 10 is obtained for the coefficient corresponding to %. Note that the horizontal axis of FIG. 9 indicates the ratio of the short time when the predicted partial drawing time Tpp is compared with the total drawing time Ta.

In the relationship shown in FIG. 9, the longer the predicted partial drawing time Tpp is shorter than the total drawing time Ta, the larger the coefficient. When the ratio of the above short time increases beyond a certain value, the coefficient is not increased. Also, when the ratio of the above-mentioned short time becomes smaller than a certain value, the coefficient is not made smaller. In FIG. 9, the upper limit of the coefficient is set to 10, and the lower limit of the coefficient is set to 0, like the lower limit of the coefficient shown in FIG.

Here, the upper limit value (50) and the lower limit value (10) of the ratio in FIG. 9 are an example, and are not limited to these values. Appropriate values are set for the upper limit value and the lower limit value according to the environment. An upper limit and a lower limit are set for the ratio so that the amount of change in the reference value does not become too large due to an accidental extreme change.

Also, the coefficient and the upper and lower limits of the ratio can be set in advance.

Then, the reference value update unit 333 calculates a new reference value Vr _n+1 based on the current reference value Vr _n and the coefficient K based on the following equation (6).

Vr _n+1 =Vr _n *(100+K)/100 (6)
As described above, the second calculation method is used when the result of partial rendering with fewer objects than the reference value is faster than full rendering. Then, using the latest update speed per object, calculate the time required for partial drawing with the number of objects of the reference value, and increase or maintain the reference value based on the result of comparing this time with the total drawing time. choose whether to As a result, it is possible to approach the appropriate reference value.

As described above, in the first method, the reference value updating unit 333 updates the reference value so as to decrease when the average partial drawing time Tpav exceeds the total drawing time Ta. Further, when the average partial drawing time Tpav is equal to or less than the total drawing time Ta, if the predicted partial drawing time Tpp is shorter than the total drawing time Ta, the reference value updating unit 333 updates the reference value so as to increase the predicted partial drawing time Ta. If the drawing time Tpp is equal to or longer than the total drawing time Ta, the reference value is maintained.

As a result, the reference value approaches the optimum value as the number of screen display updates increases. Therefore, it is possible to improve the efficiency of screen updating.

By the way, in the case of a screen including a large number of numerical displays as objects, the numerical displays are composed of two basic elements, a rectangular outline and numerical values. A rectangle-only object needs to draw only a rectangle, but a numeric display needs to draw a rectangle and a number. Therefore, when updating the display of a large number of numerical indicators, it takes a long time to draw.

In addition, the alarm component displays the time when the alarm is to be issued, the content of the alarm, the state of occurrence of the alarm, etc., and is configured by combining character displays for displaying the respective content in a format similar to a table. For example, the corresponding character display is displayed in red for the activated alarm, and the corresponding character display is displayed in green for the restored alarm.

Also, in the trend graph, many graphs are represented in one square.

In this way, multiple parts are rendered in a composite part composed of a plurality of parts. In a screen containing a large number of composite parts, when most of the composite parts change, drawing takes a particularly long time and the reference value becomes large.

On the other hand, in the first method, a ratio is obtained based on the average partial drawing time Tpav, and a new reference value is calculated based on a coefficient corresponding to this ratio. As a result, particularly when the average partial drawing time Tpav is close to the total drawing time Ta, a large change in the partial drawing time Tp that may occur suddenly (for example, when scrolling the above-mentioned alarm parts or trend graph) erroneous update of the reference value due to display update) can be suppressed.

Note that when there is a large difference between the average partial drawing time Tpav and the total drawing time Ta, even if a large change in the partial drawing time Tp suddenly occurs, the reference value is not so affected.

Next, the second technique will be explained. FIG. 10 is a flow chart showing another processing procedure for updating reference values by the programmable display device 1 .

As shown in FIG. 10, first, when the screen is switched, the drawing unit 331 draws the whole (step S31). In step S<b>31 , the drawing time measuring unit 332 measures the overall drawing time Ta required for the overall drawing and records it in the main memory 12 .

At the first display update of the switched screen, the drawing unit 331 performs partial drawing (step S32). In step S<b>32 , the drawing time measurement unit 332 measures the partial drawing time Tp required for the partial drawing and records (registers) it in the main memory 12 . In step S32, the drawing time measurement unit 332 records (sets) the number of objects drawn at the time of the first display update (object number upper limit Nulmt) in the main memory 12 as a reference value (initial total value). .

When the drawing unit 331 shifts to updating the screen for the second time or later (step S33), the reference value updating unit 333 determines whether or not the recorded partial drawing time Tp is less than the total drawing time Ta. (step S34). In this determination, if the reference value updating unit 333 determines that the partial drawing time Tp is less than the total drawing time Ta (YES), the updated object count Nud, which is the number of objects that need to be updated (the number of objects that change), It is determined whether or not (total value) is equal to or less than the object number upper limit Nulmt (step S35).

In this determination, if the reference value updating unit 333 determines that the update object count Nud is equal to or less than the object count upper limit value Nulmt (YES, first state), the drawing unit 331 performs partial drawing (step S36). In step S<b>35 , the drawing time measurement unit 332 measures the actual drawing time Tr required for the partial drawing and records it in the main memory 12 .

Next, the reference value update unit 333 determines whether or not the actual drawing time Tr is equal to or greater than the latest recorded overall drawing time Ta (step S37). In this determination, if the reference value updating unit 333 determines that the actual drawing time Tr is longer than or equal to the total drawing time Ta (YES), it updates the partial drawing time Tp in the main memory 12 to the actual drawing time Tr, 12 is updated to the updated object number Nud (step S38), and the process returns to step S33. Further, when the reference value updating unit 333 determines in step S37 that the partial drawing time Tp is less than the total drawing time Ta (NO), the partial drawing time Tp and the object number upper limit value Nulmt are not updated. , the process returns to step S33.

In step S35, when the reference value updating unit 333 determines that the update object number Nud exceeds the object number upper limit value Nulmt (NO, second state), the drawing unit 331 performs partial drawing (step S39). After that, the reference value update unit 333 determines whether or not the actual drawing time Tr is equal to or longer than the latest recorded overall drawing time Ta (step S40). In this determination, if the reference value updating unit 333 determines that the actual drawing time Tr is equal to or longer than the total drawing time Ta (YES), it calculates and updates the partial drawing time Tp and the object number upper limit value Nulmt as follows. (step S41), and the process returns to step S33.

In step S41, the reference value update unit 333 calculates the average of the current object count upper limit value Nulmt and the updated object count value Nud, and updates this value as the new object count upper limit value Nulmt. Also, in step S41, the reference value update unit 333 calculates the average of the partial drawing time Tp and the actual drawing time Tr, and updates the value as the new partial drawing time Tp.

Also, in step S40, when the reference value updating unit 333 determines that the actual drawing time Tr is less than the total drawing time Ta (NO), the process proceeds to step S38.

Further, in step S34, when the reference value updating unit 333 determines that the partial drawing time Tp is equal to or longer than the total drawing time Ta (NO), it determines whether or not the update object count Nud is equal to or less than the object count upper limit value Nulmt. (step S42).

In this determination, if the reference value updating unit 333 determines that the update object count Nud is equal to or less than the object count upper limit value Nulmt (YES, third state), the drawing unit 331 performs partial drawing (step S43), and performs processing. is returned to step S33. In step S43, the reference value update unit 333 updates the partial drawing time Tp in the main memory 12 to the actual drawing time Tr, and updates the object number upper limit value Nulmt in the main memory 12 to the updated object number Nud.

Further, in step S42, when the reference value updating unit 333 determines that the update object number Nud exceeds the object number upper limit value Nulmt (NO, fourth state), the drawing unit 331 performs the entire drawing (step S44), The process is returned to step S33. In step S44, the drawing time measurement unit 332 updates the overall drawing time Ta in the main memory 12 to the overall drawing time Ta required for the overall drawing.

Next, an example in which the above processing is specifically performed will be described with reference to Table 1.

At the time of screen switching, the rendering unit 331 performs the entire rendering with the update object count Nud of 100. FIG. At this time, the actual drawing time Tr required for the entire drawing, that is, the total drawing time Ta is 1.1 s. The drawing time measuring unit 332 records this value in the main memory 12 .

When the screen is subsequently updated for the first time, the drawing unit 331 performs partial drawing with the update object count Nud of 30. FIG. At this time, the actual drawing time Tr required for partial drawing, that is, the partial drawing time Tp is 0.6 s. The drawing time measuring unit 332 records this value in the main memory 12 . Further, the reference value updating unit 333 records the update object number Nud of 30 in the main memory 12 as the reference object number.

At the time of the second update, the partial drawing time Tp (0.6 s) is less than the total drawing time Ta (1.1 s) (YES in step S34), and the update object count Nud (40) is equal to the object count upper limit value Nulmt. (30) is exceeded (NO in step S35).

Therefore, in this case, the drawing unit 331 performs partial drawing (step S39). Also, since the actual drawing time Tr is less than the total drawing time Ta (NO in step S40), the reference value updating unit 333 updates the actual drawing time Tr as the partial drawing time Tp, and changes the number of updated objects Nud to the number of objects. It is updated as the upper limit value Nulmt (step S38).

At the time of the third update, the partial drawing time Tp (0.8 s) is less than the total drawing time Ta (1.1 s) (YES in step S34), and the update object count Nud (80) is equal to the object count upper limit value Nulmt. (40) is exceeded (NO in step S35).

Therefore, in this case, the drawing unit 331 performs partial drawing (step S39). Also, since the actual drawing time Tr (1.6 s) for partial drawing is equal to or longer than the total drawing time Ta (YES in step S40), the reference value update unit 333 calculates the average value of the partial drawing time Tp and the actual drawing time Tr. 1.2 s as the partial drawing time Tp, and 60, which is the average value of the updated number of objects Nud and the upper limit of the number of objects Nulmt, is updated as the upper limit of the number of objects Nulmt (step S41).

At the time of the fourth update, the partial drawing time Tp (1.2 s) exceeds the total drawing time Ta (1.1 s) (NO in step S34), and the number of updated objects Nud (70) reaches the object number upper limit Nulmt ( 60) (NO in step S42). Therefore, in this case, the drawing unit 331 performs the overall drawing, and the drawing time measurement unit 332 updates the overall drawing time Ta (step S44).

At the time of the fifth update, the partial drawing time Tp (1.2 s) exceeds the total drawing time Ta (1.12 s) (NO in step S34), and the number of updated objects Nud (55) reaches the object number upper limit Nulmt ( 60) below (YES in step S42). In this case, the drawing unit 331 performs partial drawing (step S43). In addition, the reference value updating unit 333 updates the partial drawing time Tr (1.1 s) as the partial drawing time Tp, and updates the update object number Nud (55) as the object number upper limit value Nulmt.

As described above, in the second method, the length of the partial drawing time Tp relative to the total drawing time Ta and the size of the updated object number Nud relative to the object number upper limit Nulmt are evaluated from the second and subsequent screen display updates. Then, the partial drawing time Tp and the object number upper limit Nulmt are updated based on the result.

As a result, the reference value approaches the optimum value as the number of screen display updates increases. Therefore, it is possible to improve the efficiency of screen updating.

Also, unlike the first method, reference values are not set in advance, and each value of the total drawing time Ta, the partial drawing time Tp, and the object number upper limit value Nulmt is appropriately updated each time the screen display is updated. As a result, the reference value can be brought close to the optimum value in a short period of time.

By the way, in this embodiment, the reference value is set for each screen. As a result, the reference value differs between a screen containing an object with a long drawing time and a screen containing an object with a short drawing time. If you optimize the reference value on the screen that is displayed regardless of the screen, after optimizing the reference value of a certain screen, display another screen to re-optimize the reference value and return the display to the certain screen. In this case, the reference value needs to be optimized again, resulting in waste. Even if the screen is switched when the reference value is not optimized, optimization can be performed continuously instead of optimizing from the beginning when returning to the same screen, so the reference value is the optimal value. can shorten the time to reach

For example, for two screens containing 100 numerical displays, when displaying the measured values of the control device 2 such that almost all the numerical displays are updated every 100 ms, the necessity of partial drawing is determined. The screen can be updated faster by drawing the entire screen without On the other hand, when displaying the measured values of the control device 2 that change once every 1 s, the overall drawing is slow. Even on the same screen, the optimum value of the reference value changes depending on the number of objects and how changes are reflected on the objects.

As for "greater than" and "less than" in each determination step in the flowcharts of FIGS. Also, "exceeding" and "less than" in each determination step may include the case of equality if there is no contradiction in the processing before and after.

[Embodiment 2]
Embodiment 2 of the present invention will be described as follows. In addition, in this embodiment, the same code|symbol is added about the component which has the same function as the component in Embodiment 1, and the description is abbreviate|omitted.

FIGS. 11A and 11B are diagrams showing the relationship between an object and a rectangle defining the area when the reference value is defined by the area of the object. FIG. 12 is a diagram showing an example of the ratio of each object to the area of the entire screen, which is used for updating the reference value when the reference value is defined by the area of the object.

In the first embodiment, the reference value is defined by the number of objects, but in this embodiment, the reference value is defined by the ratio of the area of objects to the area of the entire screen (area ratio).

Specifically, in the first method applied to the present embodiment, the reference value is preset with an arbitrary area ratio. As for the second method applied to the present embodiment, the reference value is updated with the upper limit of the area ratio (sum of changed object area ratios) instead of the upper limit of the number of objects. The configuration of the programmable display 1 other than these is the same as the programmable display 1 in the first embodiment.

Here, the area of an object is obtained from the smallest rectangular area that includes the object. If the object is a rectangle, the rectangular area equals the object. On the other hand, as shown in FIG. 11A, when the object is a circle E1, the area of the object is calculated by a rectangular area R1 circumscribing the circle E1. Also, as shown in FIG. 11B, when the object is an ellipse E2, the area of the object is calculated by a rectangular area R2 that circumscribes the ellipse E2. Objects have area percentages as their eigenvalues.

The drawing editing unit 41 of the PC 4 calculates the area of the object and, as shown in FIG. 12, the ratio (%) of the area of the object to the area of the entire screen. This area ratio information is transferred from the PC 4 to the programmable display 1 and stored in the user memory 14 together with the screen data.

In the programmable display device 1 according to this embodiment, the reference value is defined by the area ratio of the object. Smaller objects take less time to draw, while larger objects take longer to draw. For this reason, on a screen including objects of different sizes, the drawing time varies according to the changing size of the objects. Therefore, by defining the reference value by the area ratio of the object, it is possible to more appropriately determine whether to perform the entire drawing or the partial drawing even if there is a difference in size between the objects included in the screen. can.

[Embodiment 3]
Embodiment 3 of the present invention will be described as follows. In addition, in this embodiment, the same code|symbol is added about the component which has the same function as the component in Embodiment 1, and the description is abbreviate|omitted.

In the first embodiment, the reference value is defined by the number of objects, but in this embodiment, the reference value is defined by the weight of the objects.

Specifically, in the first method applied to this embodiment, the reference value is set in advance as an arbitrary ratio to the sum total of the weights of all the objects on the screen. In the second method applied to this embodiment, the reference value is updated with the upper limit of the total weight of objects (the total weight of changed objects) instead of the upper limit of the number of objects. The configuration of the programmable display 1 other than these is the same as the programmable display 1 in the first embodiment.

Here, the weight is defined by multiplying the basic weight, the ratio of the size to the resolution of the rectangular area defining the object, and the decoration weight of the object. Objects have weights assigned according to the properties of the objects as their eigenvalues.

As shown in Table 2, the basic weight is predetermined according to the shape of the figure. A larger base weight is assigned to a more complex object that takes longer to draw.

As shown in Table 3, the decoration weight is predetermined according to the type of decoration, the fineness of decoration, and the like. As with the basic weight, the decoration weight is given a larger value for decorations that take longer to draw. For example, decorations have different weights depending on whether they are painted or not, and gradation (vertical and horizontal are different). In the case of vertical gradation, each line has the same color, and the shade changes from line to line. In the case of horizontal gradation, even in the same line, the shade changes depending on the angle.

Note that the weights shown in Tables 2 and 3 are merely examples, and the weights given to objects differ according to the form of the object.

In the programmable display 1 according to this embodiment, the reference value is defined by the weight of the object. An object with a simple shape takes a short time to draw, but an object with a complicated shape takes a long time to draw. Also, the time required for drawing differs depending on the presence or absence of decoration and the form. For this reason, on a screen including objects with different weights, the drawing time differs according to the changing weight of the objects. Therefore, by defining the reference value by the weight of the object, even if there is a difference in weight between the objects included in the screen, it is possible to more appropriately determine whether to perform the whole drawing or the partial drawing.

[Example of realization by software]
The control block (particularly, the display control unit 32) of the programmable display 1 may be implemented by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be implemented by software.

In the latter case, the programmable display 1 is provided with a computer that executes instructions of a program, which is software that implements each function. This computer includes, for example, one or more processors, and a computer-readable recording medium storing the above program.

In the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. For example, the CPU 11 can be used as the processor.

As the recording medium, a "non-temporary tangible medium" such as a ROM 13, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Moreover, the programmable display device 1 may include a main memory 12 for developing the above program.

Also, the program may be supplied to the computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. Note that one aspect of the present invention can also be implemented in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

[Additional notes]
The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

1 Programmable display (screen display device)
16 Display panel 331 Rendering unit 332 Rendering time measurement unit 333 Reference value updating unit Ta Overall rendering time Tp Partial rendering time Tpp Predicted partial rendering time Tr Actual rendering time Nulmt Object number upper limit (reference value)
Nud Number of updated objects (total)

Claims (10)

A screen display device for displaying a screen containing at least one object,
Based on a reference value, it is predicted which of the whole drawing that draws the entire screen and the partial drawing that draws the object that changes on the screen can update the screen faster, and the predicted whole drawing or the a drawing unit that draws the screen by partial drawing;
A screen display device, comprising: a reference value updating unit that updates the reference value according to at least the length of the partial drawing time required for the partial drawing relative to the overall drawing time required for the entire drawing. . each of the objects has a unique eigenvalue;
The reference value is set in advance at an arbitrary ratio to the total sum of the eigenvalues for all the objects on the screen,
The drawing unit performs the entire drawing when a total value obtained by totaling the eigenvalues of the changing object on the screen is equal to or greater than the reference value, and when the total value is less than the reference value, the do partial drawing,
The reference value updating unit
updating to lower the reference value when the partial drawing time exceeds the overall drawing time, and updating to raise the reference value when the partial drawing time is equal to or less than the overall drawing time; or 2. The screen display device according to claim 1, wherein the reference value is maintained. The reference value updating unit
When the partial drawing average time, which is the average of the times required for the partial drawing of a specified number of times, exceeds the overall drawing time, the reference value is updated so as to be lowered according to the ratio of the partial drawing average time to the overall drawing time. death,
When the partial drawing average time is equal to or less than the overall drawing time, the screen is predicted by multiplying the average drawing time per one of the objects drawn by the partial drawing of the specified number of times by the reference value. calculating a predicted partial drawing time required for the partial drawing;
when the predicted partial drawing time is less than the total drawing time, updating the reference value so as to increase in accordance with the ratio of the predicted partial drawing time to the total drawing time;
3. The screen display device according to claim 2, wherein the reference value is maintained when the predicted partial drawing time is equal to or longer than the total drawing time. each of the objects has a unique eigenvalue;
The drawing unit
performing the entire drawing when the display of the screen is switched, and performing the partial drawing at the first drawing update of the switched display of the screen;
The reference value updating unit
registering the entire drawing time and the partial drawing time, and setting an initial total value obtained by summing the peculiar values of the object drawn at the first drawing update of the switched display screen on the screen as the reference value; ,
The drawing unit, at the time of drawing update after the second time,
When the partial drawing time is less than the entire drawing time, and when the total value obtained by summing the eigenvalues of the changing object on the screen is equal to or less than the reference value,
When the partial drawing time is less than the total drawing time and the total value exceeds the reference value in a second state, or
performing the partial drawing when the partial drawing time is equal to or longer than the overall drawing time and in a third state in which the total value is equal to or less than the reference value;
performing the overall drawing when the partial drawing time is equal to or longer than the overall drawing time and in a fourth state in which the total value exceeds the reference value;
The reference value updating unit, when updating the drawing for the second time or later,
when the actual drawing time required for the partial drawing in the first state is equal to or longer than the overall drawing time, when the actual drawing time in the second state is less than the overall drawing time, or in the third state when the partial drawing time is updated to the actual drawing time, and the reference value is updated to the total value;
When the actual drawing time in the second state is equal to or longer than the total drawing time, the reference value is updated to an average value of the total sum value and the reference value, and the partial drawing time is combined with the actual drawing time. Update to the average value with partial drawing time,
2. The screen display device according to claim 1, wherein, in said fourth state, said overall drawing time is updated to said overall drawing time required for said newly performed overall drawing. 5. The screen display device according to claim 2, wherein the eigenvalue is a number of units. 5. The screen display device according to any one of claims 2 to 4, wherein the eigenvalue is a ratio of the area of the object to the entire area of the screen. 5. The screen display device according to any one of claims 2 to 4, wherein the eigenvalue is a weight given according to the characteristics of the object. When performing the partial drawing, the drawing unit determines whether the plurality of objects overlap on the screen based on overlap information indicating that the plurality of objects overlap, which is set for each screen. 8. The screen display device according to any one of claims 1 to 7, wherein when at least one of the plurality of objects changes, the plurality of overlapping objects are drawn. The drawing unit determines the most efficient drawing order when there are a plurality of drawing orders for drawing the plurality of overlapping objects, and draws the plurality of overlapping objects according to the drawing order. 9. The screen display device according to claim 8, wherein: 10. The screen display device according to claim 1, wherein the reference value is set for each screen.

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