JPH07104866B2 - Map search device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an image recording / display device, and more particularly to a map search device for displaying map information.

(Prior Art) Conventionally, in this type of map search device, when an image in the vicinity of the range stored in the image memory is displayed by scrolling the display screen, the display screen is stored in the image memory. It was configured to start the expansion of the neighboring image when it hits the edge of the image.

(Problems to be Solved by the Invention) In the above-described conventional map search device, the scrolling display screen collides with the end of the image stored in the image memory, and then a nearby image is expanded and stored in the image memory. Therefore, there is a drawback in that scrolling is stopped for the time required for decompression and the display of nearby images is delayed.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a map search device capable of displaying an image without stopping the scroll when the screen is scrolled.

(Means for Solving the Problem) The map search device according to the present invention comprises a codec, an image memory, a frame memory, and means for performing time-division processing.

The codec is for compressing / decompressing image information such as maps and drawings.

The image memory is for storing the decompressed image.

The frame memory is for displaying the image of the image memory on the display.

When the scrolling direction is indicated with respect to the currently represented screen, the means for repeatedly performing the time division displays, in the frame memory, an image in the transfer range in the scrolling direction out of the image storage range stored in the image memory. The operation of transferring and the operation of expanding the image of the next image storage range on the extension line of the scroll direction and storing it in the image memory are repeatedly performed in a time division manner.

(Example) Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a map search device according to the present invention.

In FIG. 1, 1 is a disk device, 2 is a codec,
3 is an image memory, 4 is a frame memory, and 5 is a display.

In FIG. 1, a disk device 1 stores compressed data, and a codec 2 expands the compressed data read from the disk device 1 to restore an image. The image memory 3 can store a plurality of images decompressed by the codec 2, and the frame memory 4 takes out only the portion to be displayed from the image memory 3 and displays the image on the screen which is constantly transferred to the display 5. It is the same size memory.

FIG. 2 is an explanatory diagram showing the relationship between the image storage range on the image memory and the range transferred to the frame memory according to the present invention.

In FIG. 2, 6 is a range of the image memory 3, 7 is a first image storage range inside the image memory 3, 8 is a first transfer range for directly transferring the contents to the frame memory 4,
9 is the second transfer range to be transferred to the frame memory 4 after scrolling, 10 is the third transfer range to be further scrolled and then transferred to the frame memory 4, 11 is the next expansion along with the scroll This is the second image storage range of the image to be stored in the following manner.

Next, the operation of the map search device according to the present invention will be described with reference to FIGS. 1 and 2.

First, the images shown in the first image storage range 7 are stored in the image memory 3, and the images shown in the first transfer range 8 have already been transferred to the frame memory 4 and are displayed on the display 5. ing. Here, in order to display the left side of the currently displayed first transfer range 8, the scroll is performed in the direction of the second transfer range 9. In this case, the image is transferred from the image memory 3 to the frame memory 4.

In parallel with the above, in order to store the image shown in the second image storage range 11, the image read from the disk device 1 by time division is expanded by the code disk 2 and starts to be transferred to the image memory 3. By repeating the two types of transfer operations in the time division described above, the first transfer range 8 becomes the first image storage range 7
At the time of reaching the boundary of, the image of the second image storage range 11 is almost stored. Therefore, in this case, it is possible to enter the third transfer range 10 without stopping scrolling.

As described above, according to the present invention, the operation of transferring the data representing the map screen from the image memory to the frame memory for scrolling, the data decompression by the codec and the transfer operation to the image memory are time-shared. By repeating the above, there is an effect that an image in the vicinity can be displayed without apparently stopping scrolling.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a map search device according to the present invention. FIG. 2 is an explanatory diagram showing the contents of the image memory of FIG. 1 ... Disk device, 2 ... Code, 3 ... Image memory, 4 ... Frame memory, 5 ... Display, 6-11 ... Range

Claims (1)

[Claims] 1. A codec for compressing / decompressing image information such as a map and a drawing, an image memory for storing the decompressed image, and a frame memory for displaying the image of the image memory on a display. And an operation of transferring an image of a transfer range in the scroll direction out of the image storage range stored in the image memory to the frame memory when a direction of scrolling with respect to a currently displayed screen is indicated, A map search device comprising means for repeatedly performing, in a time-division manner, an operation of expanding an image in the next image storage range on an extension line in the scroll direction and storing it in an image memory.