JPS62133484A - Image display unit - 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 TECHNICAL FIELD The present invention relates to an image display device, and more particularly to an image display device that controls scroll display of a huge amount of continuous image data such as a map.

Prior Art Conventionally, image data has been displayed by constantly reading data to be displayed from display memory and outputting it on the screen.
There is a one-to-one ratio between the position of the display screen and the bit with display mercury.
Fixedly assigned to . Therefore, when displaying data in a data memory in which image data is stored in advance, the data to be displayed is read out and stored in the display memory from this data stream, and then transferred from the display memory to the display device; The data is displayed while being output to rI.

Therefore, when changing the display contents, it is necessary to replace the data currently stored (displayed) in the display memory with the data to be displayed next. That is,
It is necessary to transfer the data to be displayed next, which is stored in another part of the data memory, to the display memory and replace it with the old data (data that has been displayed up to now).

In such a display method, the screen [1-1] on the display screen is
When performing vertical or horizontal movement (including diagonal H-plane movement), it is necessary to transfer the corresponding data from the data memory to the display memory each time scroll control is performed.
Therefore, there is a drawback that the display speed of scrolling becomes extremely slow.

OBJECT OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the conventional ones, and its purpose is to improve the scrolling speed of the display screen so that it can be used for continuously displaying, for example, topographical maps, etc., which requires a huge amount of space. To provide an image display device capable of seamlessly and smoothly scrolling displaying image data from end to end.

Composition of the Invention An image display device according to the present invention is an image display device that displays image data on a display device and controls scrolling of the displayed image, and includes a plurality of memories for storing display image data and screen address generation. a scroll register that stores screen movement amount information in response to an external scroll instruction; an adder that adds the outputs of both the screen address generator and the scroll register; and each storage in the plurality of memories. an index register that stores index information each indicating a range of data, and a memory selection unit that selects at least one of the plurality of memories based on the output information of the adder and the index information,
It is characterized in that the output of the adder is used as a read address of the memory selected by the memory selection section, and the read image data is displayed on the display section.

Example The present invention will be described in detail below using the drawings.

FIG. 1 is a block diagram of an embodiment of the invention.

In the figure, CPLll is a central processing unit, and is connected via a data bus 4 to an l10 (input/output) control unit 3 that controls reading of data from an auxiliary memory 2 such as a magnetic disk in which map data is stored in advance. . Four display memories 5 to 8 are provided, and these display memories 5 to 8
The output data of is led to the CRT 9 via the data bus 4 and displayed, and the data contents of each memory 5 to 8 are updated from the auxiliary memory 2 via the data bus 4 under the control of the CP('1). controlled.

A screen address generation section 10 is provided, and a display screen address is generated under the control 2v of the CPU 1, and the conventional technology can be used as is. on the other hand,
A scroll register 11 is provided to store screen movement amount information (
(referred to as scroll information) is temporarily stored therein. The scroll information in the scroll register 11 is movement amount information for moving the display screen in the X- and Y-axis directions, and is therefore composed of a pair of register sections corresponding to the X- and Y-axis directions, respectively. The outputs of the scroll register 11 and the screen address generation unit 10 are processed in addition 1312 in each direction of the X and Y axes, and become read addresses of the display memories 5 to 8.

On the other hand, a memory selection section 13 is provided to select a memory from among the display devices 5 to 8 to display data on the display device 9. This memory selection section 13 is an adder 12
The memory chip select signal is generated by referring to the addition information.

FIG. 2 is a block diagram showing a specific example of the memory selection unit 13, which generates comparators 20 to 23 that manually receive the addition output information from the adder 12, and the inputs of each of these comparisons 2A20 to 23. It has index registers 24-27. Each index register 24-27 stores each (latest) stored data A in the display menus D5-6.
-D is provided with so-called index information indicating the range. The comparison outputs of the comparators 20-23 serve as chip select signals for the display memories 5-8.

In this configuration, the capacity 11 of the display memories 5 to 8 is set to be at least the capacity corresponding to the range of the display screen of the display device 9, and for example, data A is stored as the content of the memory 5, and data A is stored as the content of the memories 6 to 8, respectively. Data B~1] is stored. Each of these data A to D is continuous map data, and the display device 9 displays the current content A of the memory 5.
At least one part of the images is displayed.

External J: When a risk roll command arrives and scroll information, that is, screen movement amount information is stored in the scroll register 11, the adder 12 combines the current screen address and screen movement claw information from the scroll register 11. will be added. The result of this addition becomes the readout address for the display memory, but which display memory is valid is determined by the memory selection unit 13.

In this case, before the frame control 211, n consecutive map data is divided into four parts (A-D>) and sequentially stored in the memories 5 and 6, and the index register 2
4 to 27, location information on the map of each divided data A to D (for example, location information using latitude and longitude information as parameters)
are stored in correspondence with each other. Therefore, if the display screen position due to scrolling is within the range of the current contents of the display memory 5, only the output of the comparator 20 is still active because the Kawaguchi output includes index information indicating data A. Therefore, it is only scrolled within the range of data A in display memory 5.

As a result of scrolling, the display screen changes from A to D as shown in Figure 3.
If part of the data in the four ranges are all displayed on the same screen, the addition output will include index information indicating each of the data A to D, and therefore the comparator All outputs 20 to 23 are activated and all display memories 5 and 8 are selected. Since a display example as shown in FIG. 3 can occur, it is sufficient to have at least four display memories.

Next, updating of the data contents of display memories 5 to 8 will be explained. Start scrolling from the data section and scroll to data B, then to data C, then all the data displayed disappears from the screen due to scrolling, and the next data B is displayed, and then to history. As shown in Fig. 4, when data C following data B is displayed at the same time, the previous data A (because it is considered unnecessary, data AI!) is stored in memory 5. Instead of data Δ, data E following data A-D is read from the auxiliary meter 2 and converted to data E. At the same time, the index information in the index register 24 is also changed to position information indicating the range of data E. There is a tool that allows you to change your PJ.

By doing this, scrolling control of a huge amount of data such as a map can be realized extremely quickly and smoothly. This is because changing the contents of a scroll register is completed in a short period of time corresponding to one cycle of the operating clock of the register, and changing the contents of the display memory during display is not done during the frame. .

Effects of the Invention According to the present invention, an image display device capable of achieving a sufficient scrolling speed and smooth scrolling control is obtained, and the scrolling range becomes virtually infinite by using an auxiliary memory. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing a specific example of the memory selection section in FIG. 1, and FIGS. 3 and 4 are for explaining the operation of the embodiment of the present invention. It is a figure showing each aspect of a display screen. Explanation of symbols of main parts 1...CPU 5-8...Display memory 9...Display device. 10...Screen address generation unit 11...Screen register 12...Adder C) unit 13...Memory selection unit

Claims (2)

[Claims] (1) An image display device that displays image data on the display device and controls scrolling of the displayed image, which includes a plurality of memories for storing display image data, a screen address generation unit, and a scrolling instruction received from the outside. a scroll register that stores screen movement amount information in response; an adder that adds the outputs of both the screen address generation section and the scroll register; and index information that respectively indicates the range of data stored in the plurality of memories. an index register for storing, and a memory selection unit that selects at least one of the plurality of memories based on the output information of the adder and the index information, and the memory selection unit selects the output of the adder. An image display device characterized in that the read image data is used as a read address of a memory selected by , and the read image data is displayed on a display section. (2) The data stored in the plurality of memories can be updated with other data in an auxiliary memory prepared in advance, and at the same time, the index information in the index register can also be updated accordingly. Image display device of scope 1.