JPH03269570A - Display device - Google Patents

Abstract

PURPOSE:To display a cursor in a display screen regardless of a cursor position in a logical screen indicated from a host side by providing a display position control means indicating a picture position calculated by a picture position calculating means or a coordinate position set by a coordinate setting means as a display position in a physical screen. CONSTITUTION:When the screen is renewed by the designation from the host side and a new cursor position is designated, a physical screen position centering on the indicated cursor position is calculated by the picture position calculating means 1. At this time, whether or not the calculated picture position can be housed within the logical screen is discriminated by a discriminating means 2. When the calculated picture position can not be housed within the logical screen, a corresponding coordinate among the left edge, right edge, upper edge and bottom edge of the logical screen is set as the coordinate of the outer peripheral part, namely the coordinate of the left edge, right edge, upper edge and bottom edge of the physical screen. Then, the calculated screen position or the set coordinate position is designated as the physical screen position, where the cursor is displayed.

Description

[Detailed Description of the Invention] [Summary] When the screen is updated according to instructions from the host side,
Regarding display devices that can always display a cursor on the display screen, the purpose of this is to enable the cursor to be displayed on the display screen no matter where the cursor position specified by the host is on the logical screen. In a display device whose screen is updated in response to an instruction from a host, a screen position calculation means for calculating a physical screen position centered on a cursor position instructed from a host side, and a physical screen position calculated by the screen position calculation means. A determining means for comparing the calculated physical screen position with the logical screen position and determining whether or not the calculated physical screen position fits within the logical screen; , the left edge of the logical screen,
coordinate setting means for setting the corresponding coordinates among the right end, top end, and bottom end as the coordinates of the corresponding outer periphery of the physical screen; and a screen position calculated by the screen position calculation means or the screen position set by the coordinate setting means. The apparatus is configured to include a display position control means for instructing a coordinate position as a display position on a physical screen, and a display means for displaying at a position instructed by the display position control means.

[Industrial application field]

The present invention relates to a display device that can always display a cursor on a display screen when the screen is updated according to an instruction from a host side.

[Conventional technology]

In a system that updates the display screen by transferring display data from the host side to the terminal display device, if the logical screen is larger than the physical screen (the size of the display screen of the display device),
The newly specified cursor position may not exist on the physical screen, and the cursor may not be displayed on the screen.

In such a case, the user had to operate the keyboard to scroll the screen and find the cursor position.

FIG. 5 shows the cursor position on a logical screen before and after screen updating in a conventional display device, and this figure shows a case where the logical screen is larger than the physical screen.

When the screen is updated by the host and the cursor position as shown in Fig. 5(b) is specified while the display is in the display state shown in Fig. 2(a), the cursor position is outside the physical screen and the screen is The cursor disappears from the top.

[Problems to be Solved by the Invention] As described above, in conventional display devices, when the screen is updated from the host side, the new cursor position may not be displayed on the actual screen of the display device. There was an inconvenience in that the user had to scroll the screen to find the cursor each time.

SUMMARY OF THE INVENTION An object of the present invention is to enable a cursor to be displayed on a display screen no matter where the cursor position specified by the host is located on the logical screen.

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, screen position calculation means 1 calculates the physical screen position centered on the cursor position instructed by the host side.

The determining means 2 determines whether the physical screen position calculated by the screen position calculating means 1 falls within the logical screen.

When the calculated physical screen position does not fit within the logical screen, the coordinate setting means 3 sets the corresponding coordinates among the left end, right end, top end, and bottom end of the logical screen as the coordinate position of the corresponding outer periphery of the physical screen. do.

The display position control means 4 instructs the image position calculated by the image position calculation means 1 or the coordinates set by the coordinate setting means 3 as the position of the physical screen.

The display means 5 performs display with the position specified by the display position control means 4 as the physical screen position.

(Function) In the above configuration, when the screen is updated according to an instruction from the host side and a new cursor position is specified, the screen position calculation means 1 calculates the physical screen position centered on the cursor position. Ru.

At this time, it is determined whether the screen position calculated by the determining means 2 falls within the logical screen.

If the calculated screen position does not fit within the logical screen, the corresponding coordinates of the left edge, right edge, top edge, or bottom edge of the logical screen are the coordinates of the outer periphery of the physical screen, that is, the coordinates of the left edge, right edge, top edge, or bottom edge. is set as

Then, the calculated screen position or the set coordinate position is designated as the physical screen position, and the display is performed at that position.

Therefore, no matter where the cursor position moves when the screen is updated, the cursor will always be displayed on the physical screen.
The user can immediately start the input operation, and the operability can be further improved.

〔Example〕

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

FIG. 2 is a configuration diagram of a display device according to an embodiment of the present invention. In the figure, a DMA controller 11 is a circuit that performs address control, timing control, etc. in DMA (direct memory access) transfer, which transfers data directly without going through the CPU, and transfers data sent from the host side to the memory 12, etc. Transfer to. Further, key operation signals from a keyboard (KB) 13 are input to the DMA controller 11, and these signals are transferred to the CPU 14.

The CPU 14 is a central processing unit that writes data to and reads data from the memory 12.

The display control device 15 controls the display 1 made of a CRT or the like based on the display data read out from the memory 12.
This circuit performs display control of No. 6.

Next, the operation when updating the screen in the embodiment with the above configuration is as follows.
This will be explained with reference to the flowchart in FIG. 3 and the explanatory diagram of the physical screen and logical screen in FIG. 4.

Now, as shown in FIG. 4(a), the logical screen shows coordinates (A
I, Bl) as the starting point (0,0), on the coordinates (
A.I.

B, ) , (A1. B2) , (Az, Bz) ,
It consists of an area surrounded by each coordinate point of (A2.B1), and the physical screen (one that corresponds one-to-one to the display screen) is (C,
,D,) ,(C2,D,),(CZ,C2) ,(C
It is assumed that the area consists of the area surrounded by the I and D coordinate points. Further, let the horizontal width of the physical screen in the X-axis direction be L, and the vertical width in the Y-axis direction be L.

When the screen is updated according to an instruction from the host side, the display device first moves to the specified cursor position i! -(X,
Determine whether Y) exists within the above physical screen (
Figure 3, SL).

As shown in FIG. 4(b), when the updated cursor position is within the physical screen, the cursor is directly displayed at the designated position.

On the other hand, if the cursor does not exist within the specified physical screen, subtract A from the X coordinate of the cursor to the horizontal width of the physical screen in the Among the coordinate points, first, the X coordinate CI of the upper left corner position is calculated (S2).

Similarly, the vertical width A in the Y-axis direction of the physical screen is subtracted from the Y coordinate of the cursor position to calculate the Y coordinate D1 of the upper left corner position of the physical screen centered on the specified cursor (S3
).

Furthermore, the coordinates of the upper right corner, lower right corner, and lower left corner of the physical screen are calculated from the above coordinates (CI, D+) and the horizontal and vertical widths of the display screen (S4).

Next, in order to check whether the physical screen calculated in this way fits within the logical screen, first check the leftmost CI of the physical screen.
is larger than the X coordinate AI of the left end of the logical screen, and it is determined whether the left end of the physical screen falls within the logical screen (S5).

When C1 is smaller than the left end coordinate A1 of the logical screen, this means that the calculated left end of the physical screen protrudes from the logical screen, so the left end coordinate AI of the logical screen is set as the left end coordinate C1 of the physical screen (S6).

When the left end of the physical screen falls within the logical screen as determined in step S5, or after the left end coordinate A1 of the logical screen is set as the left end coordinate C1 of the physical screen in step S6, the process advances to step S7.

In step S7, it is determined whether the right end of the physical screen fits within the logical screen by comparing whether the X coordinate C2 of the right end of the physical screen is smaller than the X coordinate A2 of the right end of the logical screen.

If the X coordinate C2 of the right end of the physical screen is larger than the X coordinate A2 of the right end of the logical screen, this means that the calculated right end of the physical screen does not fit within the logical screen, so the right end coordinate A2 of the logical screen is Set as the right end seat 'tl Cz (S8).

Also, in the determination in step S7, the X coordinate C of the right end of the physical screen
2 is smaller than the right edge coordinate A2 of the logical screen, this means that the calculated right edge of the physical screen falls within the logical screen, and the process directly advances to step S9.

Next, it is determined whether the top edge of the physical screen falls within the logical screen by comparing whether the Y coordinate D+ of the top edge of the physical screen is larger than the Y coordinate B1 of the top edge of the logical screen (S9
).

If the Y coordinate D1 of the top edge of the physical screen is smaller than the Y coordinate B1 of the top edge of the logical screen, this means that the calculated top edge of the physical screen does not fit within the logical screen, so the top edge coordinate B1 of the logical screen is set to the top edge of the physical screen. (SIO).

Further, if the Y coordinate of the upper end of the physical screen is larger than the upper end coordinate B1 in the determination in step S9, this means that the calculated upper end of the physical screen falls within the logical screen, so the process directly proceeds to step 311.

Next, it is determined whether the bottom edge of the physical screen fits within the logical screen by comparing whether the Y coordinate D2 of the bottom edge of the physical screen is smaller than the Y coordinate B2 of the bottom edge of the logical screen (Sl
l).

If the Y coordinate D2 of the bottom edge of the physical screen is larger than the Y coordinate B2 of the bottom edge of the logical screen, this means that the calculated bottom edge of the physical screen does not fit within the logical screen, so the coordinate B2 of the bottom edge of the logical screen is Set as the lower end coordinate D2 of (S
12).

Through these processes, first, a physical screen centered on the cursor position designated by the host side is calculated, and when the physical screen position falls within the logical screen, display is performed using that position as the physical screen position. As a result, a cursor is displayed at the center of the display screen.

FIG. 4(C) is a diagram showing the positional relationship between the logical screen and the physical screen at this time, and the cursor designated by the host side is displayed in the center of the physical screen.

On the other hand, if the physical screen centered on the cursor position specified by the host side protrudes from the logical screen,
For example, as shown in FIG. 4(d), by setting the leftmost coordinates of the logical screen as the leftmost coordinates of the physical screen, the physical screen can be moved to a position within the logical screen where the cursor can be displayed within the screen. I can do it.

As described above, when the screen is updated according to an instruction from the host side, the specified cursor position can always be displayed on the physical screen, so the user can scroll the screen or search for the cursor. No need for manual operation, which simplifies human operation.

〔Effect of the invention〕

According to the present invention, even when the screen is updated based on an instruction from the host side, the newly specified cursor position can always be displayed on the screen, thereby improving the operability of the display device. Easy to use.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is a configuration diagram of a display device of an embodiment, Fig. 3 is a flowchart explaining the operation of the embodiment, and Fig. 4 is a diagram showing the physical Explanatory Diagram of Screen Position FIG. 5 is an explanatory diagram of the cursor position in a conventional display device. DESCRIPTION OF SYMBOLS 1... Screen position calculation means, 2... Discrimination means, 3... Coordinate setting means, 4... Display position control means, 5... Display means.

Claims (1)

[Scope of Claims] A display device in which a screen is updated in response to an instruction from a host side, comprising: screen position calculation means (1) for calculating a physical screen position centered on a cursor position instructed by the host side; a determining means (2) for comparing the physical screen position calculated by the position calculating means (1) with the logical screen position and determining whether or not the calculated physical screen position falls within the logical screen; and the determining means In the determination of (2), if the calculated physical screen position does not fit within the logical screen, set the corresponding coordinates among the left edge, right edge, top edge, and bottom edge of the logical screen as the coordinates of the corresponding outer periphery of the physical screen. and a display position for specifying the screen position calculated by the screen position calculation means (1) or the coordinate position set by the coordinate setting means (3) as the display position of the physical screen. A display device comprising: a control means (4); and a display means (5) for displaying at a position instructed by the display position control means (4).