JPH1115956A - Map information display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively and conspicuously display map information by performing coordinate conversion so that it may become a large scale to a neighborhood area of a reference point and a small scale to a peripheral area that is away from the reference point and displaying continuously each map information on the same image at the same time. SOLUTION: A map information display device 1 consists of a reference point designating device 10, a map information storage device 11, a coordinate converting device 12 and an image display device 13. The device 10 designates a reference point. Next, a coordinate converting means of the device 12 converts a coordinate. In such cases, the coordinate converting means of the device 12 has a prescribed scale rule, performs coordinate conversion so that a neighborhood area which is near the reference point may become a large scale and at the same time, performs coordinate conversion so that a peripheral area which is away from the reference point may becomes a small scale. The device 13 shows map information after conversion based on map information that is converted with a prescribed rule by the device 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map information display device.

[0002]

2. Description of the Related Art As a conventional map information display device, there is a device for displaying an image using coordinate transformation of map information by enlargement or reduction of affine transformation. There is also a display device that simultaneously displays a plurality of images having different scales. Further, as a display device in which a reference point is provided and map information near the reference point can be enlarged and viewed, Japanese Patent Application Laid-Open No. 7-220
No. 055 is disclosed.

[0003]

However, in the case of the above-mentioned conventional map information display device using the enlargement or reduction of the affine transformation, the display area of the map information in the coordinate system becomes narrow in inverse proportion to the scale factor. That is, there is a problem that if it is attempted to display the map information in detail at a large scale, the map information of the peripheral portion cannot be displayed.

In the case of a display device using a plurality of images having different scales, the size of the image display means actually used is fixed, so that the usable area per image is reduced, and a plurality of images are used. There is a problem that is difficult to see when is displayed.

Further, in the case of Japanese Patent Application Laid-Open No. Hei 7-220055, there is a problem that since the image is a perspective projection image as if the map was viewed from an oblique direction, only information on an area in a specific direction can be grasped.

Accordingly, it is an object of the present invention to provide a map information display device capable of displaying map information effectively and easily.

[0007]

A map information display apparatus according to the present invention which achieves the above object, comprises a reference point designating means for designating a reference point, a map information storage means for storing map information,
Coordinate conversion means for performing coordinate conversion of the map information based on information provided from the reference point designating means and the map information storage means, and an image for displaying the map information based on the coordinates converted by the coordinate conversion means Display means, the coordinate conversion means, a large scale for a region near the reference point specified based on a predetermined scale rule, and a small scale for a peripheral region distant from the reference point. Coordinate conversion so that the image display means continuously and simultaneously displays the scaled map information of the neighboring area and the peripheral area in the same image.

[0008] The predetermined scale rule expresses a point P of the map information, which is distant from the reference point, by a polar coordinate function F (r, θ) comprising a distance r and an angle θ, and the polar coordinate function F (r , Θ) is based on a function that decreases monotonically in a narrow sense.

According to the present invention, when displaying map information, the vicinity area near the reference point is displayed on a large scale, so that detailed map information near the reference point can be grasped, and at the same time, the distance from the reference point can be increased. The surrounding area is displayed on a small scale, so that a wide range of map information can be grasped as a whole, and the provision of the map information is effective and easy to see. That is, since the enlargement information near the reference point and the total reduction information of the peripheral area are continuously and simultaneously displayed in one image, there is no need to display a plurality of images having different enlargement ratios. It can be used effectively, and the entire map information including the peripheral area in all directions viewed from the reference point can be grasped, so that it is effective and easy to see.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a map information display device according to one embodiment of the present invention. FIG. 2 is a diagram showing a positional relationship between a reference point O before coordinate conversion and a point Pi (for example, one point) of map information. FIG.
FIG. 3 is a diagram showing a positional relationship between a reference point O ′ after coordinate transformation between the reference point O and the point Pi in FIG. 2 and a point Pi ′ in the map information. This will be described with reference to FIGS. As shown in FIG. 1, the map information display device 1 according to the present embodiment includes a reference point designating device 10, a map information storage device 11, a coordinate conversion device 12, and an image display device 13. And the coordinate conversion device 1
2 is provided with a coordinate conversion means having a predetermined scale rule for performing a coordinate conversion so that a nearby area near the reference point becomes a large scale, and a coordinate conversion so that a peripheral area distant from the reference point becomes a small scale. .

Next, the specific contents and operation of the above configuration will be described. First, the reference point O given by the reference point designating device 10 is set to O = (Xo, Yo). The map information provided by the map information storage device 11 includes a reference point O, a point {Pi of arbitrary map information on a two-dimensional plane (on a map).
, I = 1, 2,...}, And a set of lines (line segments) starting and ending with the reference point O and the point Pi.

Next, the coordinate conversion means of the coordinate conversion device 12 converts the coordinates of the reference point O and the point Pi. And
Based on the map information converted by the coordinate conversion device 12 according to a predetermined rule (that is, the converted map information represented by the reference point O ′ and the point Pi ′ of the map information), the image display device 13 Display map information for. A calculation method as an operation content of the coordinate conversion means will be described below.

First, the value of the reference point O 'converted from the reference point O by the coordinate conversion device 12 is (Xo', Yo '), and the value of the converted point Pi' of the point Pi is (Xi ', Yi'). ).
Here, (ri, θi) is calculated by Xi−Xo = ri × cos (θ
i), Yi−Yo = ri × sin (θi), (ri, θi)
Is a polar coordinate display having the reference point O as a pole and the positive direction of the X axis as a base line, ri is the length of the point O and the point Pi, θi is the angle of the point Pi measured from the positive direction of the X axis. Become. (See FIG. 2) Similarly, (ri ′, θi ′) is calculated as Xi′−Xo ′ = ri ′ × cos (θ
i ′), Yi′−Yo ′ = ri ′ × sin (θi ′), then (ri ′,
θi ′) is a polar coordinate having the reference point O ′ as a pole and the positive direction of the X axis as a base line, and ri ′ is the length between the points O ′ and Pi ′, θi ′
Is the angle of the point Pi 'measured from the positive direction of the X axis. (Figure 3
Next, an equation for coordinate conversion is given by the following equations (Equation 1) and (Equation 2).

F (ri, θi) = ri ′ (where 0 ≦ ri, L (0, θi) = 0) (Equation 1) θi = θi ′ (Equation 2) Here, the scale factor is a certain line. Since the length of the minute is the ratio before and after the coordinate conversion, to convert the coordinates so that the vicinity of the reference point becomes a large scale, and to convert the coordinates so that the surrounding area away from the reference point becomes a small scale If it is determined that the length ri of the point O and the point Pi is small, it is determined that the point Pi is in the vicinity area near the reference point, and the point Pi is subjected to coordinate transformation so as to have a large scale. If it is determined that the length ri of the point O and the point Pi is large, the point Pi is determined to be in a peripheral area away from the reference point, and the point Pi is subjected to coordinate transformation so as to have a small scale. Become.

A specific example of the contents and operation of the coordinate conversion means will be described. Here, when the direction θ is fixed and the scale S at the point P = (r, θ) is considered as a line segment having a length Δr, S = {F (r + Δr, θ) −F (r , Θ}) / {(r + Δr)
−r}, and Δr → 0, S = ∂F / ∂r
(r, θ). Then, the function F is selected such that ∂F / ∂r (r, θ) decreases monotonically in a narrow sense, the scale at the point Pi = (ri, θ) is Si, and the scale at the point Pj = (rj, θ) is As Sj, if ri <rj, then Si> Sj, and the smaller the length r from the reference point O, the smaller the scale. Conversely, if ri ≧ rj,
Si <Sj, and the scale becomes large. That is, the operating condition of the coordinate conversion means is satisfied.

Next, a specific example of a function F (r, θ) in which the function F is monotonically decreasing in a narrow sense, in other words, ΔF / ∂r (r, θ) is monotonically decreasing in a narrow sense. explain. For example, if F (r, θ) = N × {log (r + 1) + r} (where N is a positive constant) (Equation 3), then: ∂F / ∂r (r, θ) = N × {1 / (R + 1) +
1}, and ∂F / ∂r (r, θ) is a strictly monotonic decrease. Therefore, it can be said that the equation (3) is a polar coordinate function F that strictly monotonically decreases.

Next, an example in which map information is displayed using this embodiment will be specifically described. FIG. 4 is a diagram showing a screen display example of the map information display device of one embodiment according to the present invention. An example of a display of map information using the function of the above (Equation 3) is shown. For comparison with the present invention, FIG. 6 shows a display example of map information by enlarging or reducing affine transformation, which is one of the conventional techniques.

As shown in FIG. 4, enlargement information near the reference point and total reduction information in the peripheral area are continuously and simultaneously displayed in one image. With such a display, the map information around the desired reference point can be grasped in detail, and at the same time,
Since the entire information of the surrounding area in all directions viewed from the reference point can be grasped, it is easy to see. On the other hand, the display image of the related art shown in FIG. 6 has the above-described problem.

Next, another embodiment will be described. FIG.
FIG. 11 is a diagram showing a screen display example of the map information display device of another embodiment according to the present invention. In the present embodiment, a function F that decreases monotonically in a narrow sense of the following (Equation 4) is used. F (r, θ) = N × √r (where N is a positive constant) (Equation 4) In the equation (4), ∂F / ∂r (r, θ) = N × 1 / (2
× √r), and ∂F / ∂r (r, θ) is a monotone decrease in a narrow sense.

FIG. 5 shows a display example of map information using the function of the above equation (4). As shown in FIG. 5, the present embodiment is used when the map information near the reference point is slightly enlarged compared to the surrounding area, and particularly when the map information near the reference point is grasped in detail. Then, using the above two embodiments (ie, two narrowly monotone decreasing functions F) and, if necessary, using a plurality of functions F having different scales, etc., and further switching and displaying them. And it is also possible to display desired map information in an easily viewable manner.

[0021]

According to the present invention, when the map information is displayed, the vicinity of the reference point is displayed on a large scale so that the detailed map information around the desired reference point can be grasped, and at the same time, the distance from the reference point can be increased. Since the surrounding area can be displayed on a small scale to grasp the entire map information in a wide range, an effective and easy-to-view map information display device is provided. Therefore, the effect is obtained that the vehicle can be safely driven without getting tired and can reach the destination.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a positional relationship between a reference point O before coordinate conversion and a point Pi of map information.

FIG. 3 is a diagram showing a positional relationship between a reference point O ′ after coordinate conversion between the reference point O and a point Pi in FIG. 2 and a point Pi ′ of map information.

FIG. 4 is a diagram showing a screen display example of the map information display device of one embodiment according to the present invention.

FIG. 5 is a diagram showing a screen display example of a map information display device of another embodiment according to the present invention.

FIG. 6 is a diagram showing a screen display example of a conventional map information display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Map information display apparatus, 10 ... Reference point designation apparatus, 11 ...
Map information specifying device, 12: coordinate conversion device, 13: image display device.

Claims (2)

[Claims] A reference point designating means for designating a reference point; a map information storage means for storing map information; and a map information storage means for storing the map information based on information given from the reference point designating means and the map information storage means. Coordinate conversion means for performing coordinate conversion;
Image display means for displaying the map information based on the coordinates converted by the coordinate conversion means, wherein the coordinate conversion means is large for an area near the reference point specified based on a predetermined scale rule. It becomes a reduced scale, and coordinate conversion is performed so that a peripheral area distant from the reference point becomes a small scale, and the image display means converts the map information of the neighboring area and the peripheral area to a same image. A map information display device characterized in that the map information is displayed simultaneously and continuously. 2. The method according to claim 1, wherein the predetermined scale rule is a method in which a point P of the map information away from the reference point is a distance r.
And a polar coordinate function F (r, θ) consisting of
A map information display device, wherein the polar coordinate function F (r, θ) is based on a function that decreases monotonically in a narrow sense.