JPS63124085A - Graphic display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Nine industrial fields of application The present invention relates to a graphic CRT (CRT) connected as a terminal to a host computer of a supervisory control system, for example.
This invention relates to a graphic display device applied to athode Ray Tube (ray tube) 5 display devices and the like.

B0 Summary of the Invention The present invention provides a graphic display device that cuts out display information in a designated area from display information in a storage unit, writes it to a frame buffer as a digital image, and scans this to display graphic information on a screen. , Using two frame buffers, sequentially move the cutout area according to the specified unit scroll amount, write graphic information of each cutout area to the two frame buffers alternately, and alternately switch the frame buffer to be scanned. This allows the graphical information displayed on the screen to be moved smoothly.

BACKGROUND OF THE INVENTION Recently, graphic CR7 display devices have been attracting attention as terminal devices for online systems because they allow processed information to be visually recognized and judged.

For example, in centralized monitoring and control systems for disaster prevention, etc., the third
As shown in the figure, a host computer 1 corresponding to a master station collects various information from slave stations in real time, and data-processed graphic information is stored in an auxiliary storage device 1 such as a magnetic disk. The graphical information in the range required by the graphic CR7 display device 2 is transmitted to it through a communication line.

On the other hand, in the graphic CRT display device #2, the microprocessor 3 constructs the transmitted graphical information into a predetermined segment structure and stores it in the segment buffer 4 corresponding to a storage section. Then, the graphic processor 5 cuts out the graphic information in the range required for display from the graphic information in the segment buffer 4, develops bits in the corresponding position on the frame buffer 6, and writes a digital image.

The frame buffer 6 is physically a memory that has bits that correspond one-to-one to each pixel on the screen of the CRT monitor 7, and for color display, it has several bit planes and a lookup table (not shown). is used to determine the display color. For example, if the frame buffer 6 is made up of three bit planes ≠1 to ≠3, the on/off of bits corresponding to graphic information is developed as a combination of bit planes 1 to ÷3. The display on the screen of the CRT monitor 7 is performed by raster scanning the frame buffer 6 and using the display color table defined in the lookup table using the combination value of each bitplane ÷ 1 to 4I3 as an address. This is performed by applying the corresponding R (red), G (green), and B (blue) beam outputs to the CRT monitor 7.

By the way, in a centralized monitoring and control system, since it is operated for equipment installed in a wide area, it is necessary to monitor a wide display area and display a necessary range according to a display request. For this purpose, the graphic CR7 display device has a screen that moves continuously, for example along a map surface, in response to an operator's request. A so-called scrolling function is provided. In order to perform conventional scrolling, K erases the digital image that has already been written on the frame buffer 6, cuts out an area by moving the previously cut out wing area in a predetermined direction, and transfers the graphic information in the area to the frame buffer. The process of writing on 6 was repeated.

10. Problems to be Solved by the Invention However, in the conventional scrolling process, displaying and erasing the screen is manipulated back and forth, making the screen difficult to see and scrolling not smooth. An object of the present invention is to solve these problems.

Means for Solving the E0 Problem The present invention sequentially displaces a first frame buffer, a second frame buffer, and a cutout area in a storage unit in accordance with a specified scroll amount, and continuously cuts out a first frame buffer and a second frame buffer. Aft the graphic information that is being extracted according to the order of cutting out.
A display processing unit that alternately writes data into the first frame buffer and a second frame buffer; It is provided with a switching section for switching.

After writing graphic information to the first frame buffer, scan the frame buffer, cut out an area displaced by a predetermined unit scroll amount from the previous crop area, and write the graphic information therein to the second frame buffer. After writing, the scanning target is switched to the second frame buffer. This allows the graphic information to appear to move on the snow surface.

G. Embodiment FIG. 1 is a block diagram showing an embodiment of the present invention, and the same reference numerals as in FIG. 2 indicate the same or equivalent parts. In this embodiment, a first frame buffer 61 and a second frame buffer 6 are used.

The microb a set f3 has a machine 1f@ that sequentially moves the cutout area in the segment buffer 4 in accordance with a preset unit scroll amount, and the graphics processor 5 It has a function of alternately capturing the cut out graphic information into the first frame buffer 6 and the second frame buffer 6 according to the order of cutting out. In this example, the display processing unit 8 is controlled by the microprocessor 3 and the graphics processor 5. The graphics processor 5 also controls one frame buffer 6 between the first frame buffer 6 and the second frame buffer 6.
It has a function as a switching unit that switches the scanning target after the scanning of r(6*) is completed and the writing of the other frame buffer 6y(6+) is completed.

Next, the scrolling process according to the above embodiment will be described.

As shown in Figure 2, an area S is cut out from the virtual large screen M that corresponds to all the graphic information stored in the segment buffer 4, and the graphic information in that area 81 is
Assume that the data is written to the frame buffer 6I of . When moving the screen to the lower right of the virtual large screen M, the operator instructs the direction of movement using a man-machine device such as a joystick. Thereby, the microprocessor 3 cuts out an area displaced from the cutting area S1 by unit scroll amounts ΔX and Δy that are preset according to the moving direction. The extracted graphic information is then loaded into the second frame buffer 62 by the graphic processor +5. Next, the scanning target is switched from the first frame buffer 61 to the second frame buffer 6, and the cutting area S! An area S3 displaced by the unit scroll amounts ΔX and Δy is cut out from the area S3, and graphic information within the area S is written into the first frame buffer 6. Thereafter, the scanning target is switched to the jigl frame buffer 61, and the screen changes continuously in accordance with the unit scroll amount. The screen stops moving when the operator stops giving movement instructions.

H. Effects of the Invention As described above, according to the present invention, the first and second frame buffers are used and the screen is sequentially moved by a unit scroll amount by scanning these frame buffers alternately. This allows the screen to appear to be moving continuously, making it easier to see the screen.
Scroll processing is performed smoothly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a perspective view showing how graphic information is extracted, and FIG. 3 is a block diagram showing a conventional example. 1...Host computer, 2...Graphic C
RT display device, 3... microprocessor, 4...
Segment buffer, 5...Graphic buffer, 6, 6+, fig...Frame buffer, 7...
- CRT monitor, 8...display processing section.

Claims (1)

[Claims] The graphic information in a designated area is cut out from the graphic information stored in advance in the storage unit, and written as a digital image in a frame buffer, and the frame buffer is scanned to display the graphic information on the screen. In a figure display device for displaying, a first frame buffer, a second frame buffer, and a figure that is continuously cut out by sequentially moving a cutout area in the storage unit according to a preset unit scroll amount. a display processing unit that alternately writes information to the first frame buffer and the second frame buffer in accordance with the order of extraction; and a display processing unit that corresponds to the timing of writing between the first frame buffer and the second frame buffer. 1. A graphic display device comprising: a switching unit that alternately switches a scanning target at the same timing.