JPH10333557A - Map display controller and recording medium recording map display controlling program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a bird's-eye viewed map together with a character easy to read in a navigation device. SOLUTION: This map display controller for controlling a map display by a display unit 13 in the navigation device S extracts the character data from the map data to convert the map data without containing the character data to a bird's-eye view. The character data answering to places having dips (θ) of a prescribed lower limit value (θL) or above based on a point in the air as a reference of this bird's-eye view among the extracted character data are converted respectively to the bird's-eye view, and the character data answering to the places having the dips (θ) below the lower limit value (θL) among the extracted character data are converted respectively to a pseudo bird's-eye view which is made by seeing through at the dip (θ') equal to the lower limit value (θL). The map data converted to the bird's-eye view and the character data converted to the bird's-eye view and the pseudo bird's-eye view are synthesized and displayed on the display unit 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device for displaying the route of a moving object such as a vehicle or the name of a famous feature near the route together with a map to assist the moving of the moving object. It belongs to the technical field of displaying maps in bird's eye view.

[0002]

2. Description of the Related Art At present, as a positioning device for various moving objects such as a vehicle, an aircraft, a ship, etc., the position of the moving object is indicated on a map including a point where the moving object is currently located. 2. Description of the Related Art There has been known a navigation apparatus that superimposes and displays a position mark (index) to be displayed and guides a route to a destination based on the mark. Of these navigation devices, vehicle navigation devices mounted on vehicles are roughly divided into self-contained navigation devices and GPS (Global Pos
itioning System) type navigation device.

In the former, the moving direction and the moving distance of the moving body are obtained by independent sensors such as a speed sensor and an angular velocity sensor provided on the moving body, and the current position is calculated by sequentially adding the moving direction and the moving distance to a reference point. A position mark and a corresponding map are displayed on the display screen based on the current position.

In the latter, positioning radio waves from a plurality of GPS satellites launched in outer space are received by a GPS receiver, and based on the reception result, the current position of the moving object is determined by a three-dimensional survey method or a two-dimensional survey method. The position is calculated, and a position mark and a corresponding map are displayed on the display screen based on the calculated current position.

[0005] More recently, a so-called hybrid vehicle navigation device having both the above-mentioned self-standing type and GPS type functions has become popular.

[0006] Further, in each of the above-mentioned vehicle navigation devices, a device that can display a route on which a vehicle is going to travel on a map together with a famous feature on the route is also generalized.

According to each of the above-described vehicle navigation devices, the user (driver) can grasp the current position of the vehicle and a map near the current position in association with each other. Can reach the destination without hesitation.

On the other hand, with respect to the map display in each of the above-mentioned vehicle navigation devices, in recent years, a map has been displayed in a so-called bird's-eye view, mainly for the purpose of enlarging a displayable range at a time and providing a more realistic map display. Is being done.

Here, the map display based on the bird's-eye view is as follows.
For example, a map is displayed as if a road map is viewed obliquely from the sky (that is, a one-point perspective projection view in which the terrain corresponding to the map is viewed from one point in the air). Etc. are widely used.

FIGS. 17 and 18 show the bird's-eye view display.
The outline will be described with reference to FIG.

In FIG. 17, a plane M indicates a map, and a rectangle abcd indicates a display range of a display for displaying the map. And when the viewpoint is set to the position of FIG. 17,
The map range that can be seen from this viewpoint through the rectangle abcd is a trapezoid ABCD on the plane M in FIG. That is, from the viewpoint position, a map in a much wider range than the range of the rectangle abcd can be seen.
Therefore, the bird's-eye view display displays an image as if looking at the trapezoid ABCD in FIG. 17 from the viewpoint position in FIG. 17. More specifically, FIG.
18 shows an example in which a road map around the route from the current position of the vehicle to the destination is displayed in a bird's eye view on a display. FIG. 18 is a view in which the viewpoint is set in the sky in the direction opposite to the destination based on the current position, and the direction of the destination is looked down from there. When the viewpoint is placed at such a position, as shown in FIG. 18, an image in which the scale of the map is continuously increased as approaching the current position from the destination is displayed. That is, the vicinity of the current position is enlarged and displayed as compared with a case where the map is viewed two-dimensionally, and the route can be displayed over a wide range near the destination.

By using the bird's-eye view display described above, a much wider range can be displayed at a time than when a map is displayed two-dimensionally, and a more realistic map display that is closer to actual driving is possible. .

By the way, in the conventional vehicle navigation system, the names of famous buildings, intersections, and the like in addition to roads are generally displayed on a map corresponding to the position. When these names and the like are displayed while the bird's-eye view is displayed, the characters indicating the names and the like remain in a planar shape as shown in FIG. 19 (in other words, in the two-dimensional display). ) Was usually displayed.

[0014]

According to the knowledge of the applicants of the present invention, it is possible to convert a character other than a map other than a character into a bird's-eye view in the same manner as a map, or to convert a character into a bird's-eye view with the character included in the map. The conversion is considered to be technically possible. However, if a character is easily converted to a bird's-eye view, the character after conversion (hereinafter referred to as a “bird's-eye character”) will be crushed in the vertical direction as it goes farther on the display screen. Is not expected to occur. That is, if it is a map other than a character, it is crushed in the vertical direction to give a sense of perspective and presence, but in the case of a character, if it is crushed, it will be difficult to read or unreadable depending on the degree and type of character. It is expected to be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. In a navigation apparatus which displays a map by a display means to assist the movement of a moving body, a bird's-eye view map together with easy-to-read characters is displayed on a display means. It is an object of the present invention to provide a map display control device capable of displaying and a recording medium storing a map display control program.

[0016]

According to a first aspect of the present invention, there is provided a map display control device for displaying a map on a display means to assist the movement of a moving object. A map display control device for controlling display of the map, comprising: character data extraction means for extracting character data corresponding to characters from map data corresponding to the map; and Map data conversion means for converting the terrain corresponding to the map data into a bird's-eye view, which is a single-point perspective projection view of a single point in the air, and outputting bird's-eye map data;
The extracted character data corresponding to points having a depression angle θ of not less than a predetermined lower limit value θ _L (where 0 ° <θ _L <90 °) with respect to the one point in the air is converted into the bird's eye view, respectively. The bird's-eye character data is output, and one of the extracted character data corresponding to a point having a depression angle θ smaller than the lower limit value θ _{L with} respect to the one point in the air is defined as a depression angle equal to the lower limit value θ _L. character data conversion means for respectively converting into a pseudo bird's-eye view perspectiveed by θ 'and outputting pseudo bird's-eye character data, the outputted bird's-eye character data and pseudo bird's-eye character data, and the outputted bird's-eye character data and pseudo bird's-eye character Combining means for combining the output bird's-eye view map data corresponding to the data with synthetic bird's-eye view data, and displaying the combined bird's-eye view corresponding to the generated combined bird's-eye view data on the display means. Characterized by comprising a display control unit.

According to the map display control device of the present invention, first, character data corresponding to characters is extracted from the map data corresponding to the map by the character data extracting means. Next, on the other hand, map data that does not include character data is converted into a bird's-eye view, which is a single-point perspective projection view of the terrain corresponding to the map data from one point in the air, and the bird's-eye map data is output by the map data conversion means. Is done. The character data converting means on the other hand, the predetermined lower limit value as a reference one point of the air among the extracted character data to theta _L or depression angle theta
Those corresponding to points with are converted to bird's-eye views,
Bird's eye character data is output. At the same time, the lower limit θ based on the one point in the air among the extracted character data.
Those corresponding to points having a depression angle θ less than _L are lower limit values θ _L
Are converted into pseudo bird's-eye views transparently viewed at a depression angle θ ′, and pseudo bird's-eye character data is output. Thereafter, the combining means combines the output bird's-eye character data and the pseudo bird's-eye character data with the output bird's-eye map data corresponding to the output bird's-eye character data and the pseudo bird's-eye character data, and generates composite bird's-eye view data. Is generated. Finally,
The composite bird's-eye view corresponding to the generated composite bird's-eye view data is displayed on the display under control of the display controller.

According to a second aspect of the present invention, there is provided a map display control device for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting movement of a moving body. Character data extraction means for extracting character data corresponding to characters from the map data corresponding to the map, and the map data not including the character data, the terrain corresponding to the map data from one point in the air A map data conversion unit that converts a perspective one-point perspective projection view into a bird's-eye view and outputs bird's-eye map data, and converts the extracted character data with reference to the one point in the air at a point corresponding to the character data. The angle of depression θ is multiplied by a predetermined gain value g (however, 1 <g), and converted into pseudo bird's-eye views transparently at an angle of depression θ ′ equal to the angle (gθ) obtained by multiplying the pseudo bird's-eye view. Character data conversion means for outputting character data; combining the outputted pseudo bird's-eye character data with the outputted bird's-eye map data corresponding to the outputted pseudo bird's-eye character data to generate composite bird's-eye view data It is characterized by comprising a synthesizing means, and a display control means for displaying a synthetic bird's-eye view corresponding to the generated synthetic bird's-eye view data on the display means.

According to the map display control device of the present invention, first, character data corresponding to a character is extracted from the map data corresponding to the map by the character data extracting means. Next, on the other hand, map data that does not include character data is converted into a bird's-eye view, which is a single-point perspective projection view of the terrain corresponding to the map data from one point in the air, and the bird's-eye map data is output by the map data conversion means. Is done. On the other hand, the character data conversion means converts the extracted character data into an angle (gθ) obtained by multiplying the depression angle θ of the point corresponding to the character data with respect to the one point in the air by a predetermined gain value g. Are converted into pseudo bird's-eye views transparently viewed at a depression angle θ ′, and pseudo bird's-eye character data is output. afterwards,
By the combining means, the output pseudo bird's-eye character data;
The outputted bird's-eye view map data corresponding to the outputted pseudo bird's-eye view character data is combined to generate combined bird's-eye view data. Finally, the composite bird's-eye view corresponding to the generated composite bird's-eye view data is displayed on the display under the control of the display controller.

According to a third aspect of the present invention, in the map display control apparatus according to the second aspect, the character data conversion means includes a predetermined function f of the depression angle θ instead of the angle (gθ). (Θ) (however, 0 ° <f (θ) <90
(°, f (θ) is a function that decreases as θ decreases), and is converted into a pseudo bird's-eye view perspectiveed at a depression angle θ ′.

According to the map display control device of the third aspect, the character data converted by the character data conversion means is replaced with, for example, a power function of a depression angle θ, an exponent / logarithm instead of an angle (gθ). It is converted into a pseudo bird's-eye view perspectiveed at a depression angle θ ′ equal to a predetermined function f (θ) of the depression angle θ, which is various functions such as functions, cosine and sine functions.

According to a fourth aspect of the present invention, there is provided a map display control device for controlling a display of a map by the display means in a navigation device for displaying a map by a display means and assisting movement of a moving body. A predetermined lower limit θ _L (where 0 ° <θ _L <90 °) based on one point in the air among map data corresponding to the map and including character data corresponding to characters in the map. The portion corresponding to the point having the above depression angle θ is converted into a bird's-eye view which is a single-point perspective projection view of the terrain corresponding to the map data from one point in the air, and the bird's-eye view data is output. convert the portion corresponding to the point having the depression angle theta of the less than the lower limit theta _L a point of the air as a reference to the pseudo-bird's eye view obtained by transmission at depression angle theta 'equal to said lower limit theta _L, leaving the pseudo bird's-eye view data A map data converting means for, characterized in that the bird's-eye view corresponding to the bird's-eye view data and pseudo bird's-eye view data the output and a display control means for displaying on the display means.

According to the map display control device of the fourth aspect, the map data converting means corresponds to a portion of the map data corresponding to a point having a depression angle θ that is equal to or greater than a predetermined lower limit value θ _{L with} respect to one point in the air. Is converted to a bird's-eye view, and bird's-eye view data is output. At the same time, a portion of the map data corresponding to a point having a depression angle θ smaller than the lower limit value θ _{L with} respect to the one point in the air is converted into a pseudo bird's-eye view transparently viewed at a depression angle θ ′ equal to the lower limit value θ _L. Bird's eye view data is output. Finally, a bird's-eye view corresponding to the generated bird's-eye view data and the pseudo bird's-eye view data is displayed on the display means under the control of the display control means.

According to a fifth aspect of the present invention, there is provided a map display control device for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting movement of a moving body. In addition, map data including character data corresponding to the map and corresponding to characters in the map is converted into a predetermined gain value g (where 1 < g. Display control means for displaying the data on the display means.

According to the map display control device of the present invention, the map data including the character data is converted by the map data converting means into a predetermined gain value g at a depression angle θ with respect to one point in the air held at each point. Are converted into pseudo bird's-eye views, which are perspectiveed at a depression angle θ ′ equal to the angle (gθ) obtained by multiplying the data, and pseudo bird's-eye view data is output. Finally, a bird's-eye view corresponding to the generated pseudo bird's-eye view data is displayed on the display means under the control of the display control means.

According to a sixth aspect of the present invention, in the map display control apparatus according to the fifth aspect, the map data conversion means includes a predetermined function f of the depression angle θ instead of the angle (gθ). (Θ) (however, 0 ° <f (θ) <90
(°, f (θ) is a function that decreases as θ decreases), and is converted into a pseudo bird's-eye view perspectiveed at a depression angle θ ′.

According to the map display control device of the present invention, the map data including character data is replaced by, for example, a power function of the depression angle θ, an exponent / logarithm, instead of the angle (gθ). Depression angle θ ′ equal to a predetermined function f (θ) of depression angle θ, which is a function, various functions such as cosine and sine functions.
Is converted into a pseudo bird's-eye view seen through.

[0028] A computer-readable recording medium recording the map display control program according to claim 7 comprises:
A map display control device including a computer for controlling the display of the map by the display means in a navigation device that displays the map by the display means and assists the movement of the moving object, includes a character from the map data corresponding to the map. Character data extraction procedure to extract the character data corresponding to, the map data that does not include the character data, the topography corresponding to the map data is converted into a bird's-eye view which is a single-point perspective projection view from a point in the air, A map data conversion procedure for outputting bird's-eye view map data, and a depressed angle θ of a predetermined lower limit θ _L (0 ° <θ _L <90 °) or more based on the one point in the air among the extracted character data. The bird's-eye view is converted to the one corresponding to the possessed point, and bird's-eye character data is output. It said respective transformed those corresponding to the point having the depression angle theta is less than the lower limit theta _L pseudo bird's eye view obtained by transmission at depression angle theta 'equal to said lower limit theta _L Te, and character data conversion procedure of outputting the pseudo bird's-eye view character data Combining the output bird's-eye character data and the pseudo bird's-eye character data with the output bird's-eye map data corresponding to the output bird's-eye character data and the pseudo bird's-eye character data to generate synthetic bird's-eye view data And a display control procedure for causing the display means to display a composite bird's-eye view corresponding to the generated composite bird's-eye view data. The computer-readable recording medium records a map display control program. .

According to the recording medium of the present invention, the map display control program recorded on the recording medium is read by a map display control device equipped with a computer, and the program is executed. A map display control device according to claim 1 is realized.

[0030] A computer-readable recording medium recording the map display control program according to claim 8 comprises:
A map display control device including a computer for controlling the display of the map by the display means in a navigation device that displays the map by the display means and assists the movement of the moving object, includes a character from the map data corresponding to the map. Character data extraction procedure to extract the character data corresponding to, the map data that does not include the character data, the topography corresponding to the map data is converted into a bird's-eye view which is a single-point perspective projection view from a point in the air, A map data conversion procedure for outputting bird's-eye view map data, and converting the extracted character data to a predetermined gain value g (where 1
<G) a character data conversion procedure of respectively converting to a pseudo bird's-eye view perspectiveed at a depression angle θ ′ equal to an angle (g θ) obtained by multiplying the pseudo bird's-eye character data, A combining procedure for combining the outputted bird's-eye view map data with the outputted bird's-eye map data corresponding to the outputted pseudo-bird's-eye character data, and a combined bird's-eye view corresponding to the generated combined bird's-eye view data to the display means. It is a computer-readable recording medium on which a map display control program for executing a display control procedure to be displayed is recorded.

According to the recording medium of the present invention, the map display control program recorded on the recording medium is read by a map display control device equipped with a computer, and the program is executed. A map display control device according to a second aspect is realized.

[0032] A computer-readable recording medium recording the map display control program according to claim 9 comprises:
A map display control device having a computer for controlling the display of the map by the display means in a navigation device for displaying the map by the display means and assisting the movement of the moving body, A predetermined lower limit value θ _L (where 0 ° <θ _L <90) based on one point in the air among the map data including the character data corresponding to the character
°) A portion corresponding to a point having the above depression angle θ is converted into a bird's-eye view, which is a one-point perspective projection view of the terrain corresponding to the map data from one point in the air, and outputs bird's-eye view data, and outputs the map data. The part corresponding to a point having a depression angle θ less than the lower limit value θ _{L with} respect to the one point in the air is converted into a pseudo bird's-eye view perspectively viewed at a depression angle θ ′ equal to the lower limit value θ _L , and pseudo bird's-eye view data is output. Computer-readable recording for recording a map display control program for executing a map data conversion procedure to be executed and a display control procedure for displaying a bird's-eye view corresponding to the outputted bird's-eye view data and pseudo bird's-eye view data on the display means. It is a medium.

According to the recording medium of the present invention, the map display control program recorded on the recording medium is read by a map display control device equipped with a computer, and the program is executed. A map display control device according to a fourth aspect is realized.

According to a tenth aspect of the present invention, there is provided a computer-readable recording medium storing the map display control program, wherein the map display control means displays the map by a display means to assist the movement of a moving body. A map display control device provided with a computer for controlling the display, the map data including the character data corresponding to the map and the characters in the map, the depression angle with respect to one point in the air that each point has A predetermined gain value g for θ
(However, a map data conversion procedure of converting into a pseudo bird's-eye view perspectiveed at a depression angle θ ′ equal to the angle (gθ) obtained by multiplying by 1 <g) and outputting pseudo bird's-eye view data, and the output pseudo bird's-eye view data And a display control procedure for causing the display means to display a bird's-eye view corresponding to (i). The computer-readable storage medium stores a map display control program.

According to the recording medium of the present invention, the map display control program recorded on the recording medium is read by a map display control device equipped with a computer, and the program is executed. A map display control device according to a fifth aspect is realized.

[0036]

Next, a preferred embodiment of the present invention will be described with reference to the drawings. In the following embodiments, a case will be described in which the present invention is applied to a vehicle navigation device in an automobile or the like.

(I) Apparatus Configuration First, the overall configuration of the vehicle navigation apparatus according to the present embodiment will be described with reference to FIG.

As shown in FIG. 1, the vehicle navigation device S detects an acceleration in a traveling direction actually applied to the vehicle when the vehicle starts, stops, accelerates, or decelerates, and outputs acceleration data. An angular velocity sensor 2 for detecting angular velocity during rotation of the vehicle and outputting angular velocity data and relative azimuth data, a travel distance sensor 3 for detecting a vehicle speed pulse signal corresponding to the rotation of the wheels, and a GP.
It has a GPS receiver 4 that receives radio waves from the S satellite and outputs GPS positioning data such as the latitude and longitude where the vehicle is located and outputs absolute azimuth data of the traveling direction of the vehicle. Here, examples of the acceleration sensor 1 include various types such as a semiconductor acceleration sensor of a capacitance type, a piezo type, and the like, and a piezoelectric element type acceleration sensor.

Further, the navigation device S includes an acceleration sensor 1, an angular velocity sensor 2, a traveling distance sensor 3, and a GPS.
Based on acceleration data, relative azimuth data, angular velocity data, mileage data, GPS positioning data, and absolute azimuth data output from the receiver 4, a system controller 5 for controlling the entire navigation device and various data are input. Under the control of an input device 11 such as a key operation panel and a remote controller, and a system controller 5, a DVD-ROM (DVD Read Only Memory) disk DK1 and a CD-ROM (Compact Disk Read Only M
emory) A DVD-R for reading and outputting various data such as map data including road data indicating the number of lanes and road width and data indicating detailed information of each facility from the disk DK2.
OM drive 12a and CD-ROM drive 12b
And a display unit 13 for displaying various display data under the control of the system controller 5, and a sound reproducing unit 18 for reproducing and outputting various audio data under the control of the system controller 5. VICS (Vehicle Information and Communication)
VICS receiver 2 that receives traffic congestion information based on
2 is provided.

In this embodiment, the DVD-R
Although both the OM disk DK1 and the CD-ROM disk DK2 are used, if one of them stores all the map information and the like necessary for the navigation device S, a DVD-ROM for reading the map information is used. There is no problem if the ROM drive 12a or the CD-ROM drive 12b is provided. Further, a configuration may be adopted in which a part of the information is stored on one disk and the remaining part is stored on the other disk. However, in general, DV
The D-ROM disk DK1 is superior in terms of storage capacity.
On the other hand, having the CD-ROM disk drive 12b is advantageous in that the existing CD-ROM disk DK2 storing map information can be utilized.

The system controller 5 has a GPS
The interface unit 6 that performs an interface operation with an external sensor such as the receiver 4 and the number of pulses in the vehicle speed pulse signal from the traveling distance sensor 3 are measured to calculate the traveling distance of the own vehicle and control the entire system controller 5. CPU 7 and system controller 5
(Read) that stores a control program for controlling the
Only Memory) 8 and a RAM for writably storing various data such as path data preset by a user via the input device 11
9; an input device 11, a DVD-ROM drive 12a, a CD-ROM drive 12b, a display unit 13, a sound reproduction unit 18, and a VICS receiving unit 2.
2 is connected via a bus line 10.

The display unit 13 comprises a graphic controller 14 for controlling the entire display unit 13 based on control data sent from the CPU 7 via the bus line 10, and a memory such as a VRAM (Video RAM).
A buffer memory 15 that temporarily stores image information that can be displayed immediately, and a display control unit 16 that controls the display of a display 17 such as an LCD device or a CRT display device based on image data output from the graphic controller 14.
And the display 17.

The sound reproducing unit 18 is a DVD-ROM
Drive 12a, CD-ROM drive 12b or RA
A D / A converter 19 for performing D / A conversion of audio digital data sent from the M9 via the bus line 10,
It is configured to include an amplifier 20 for amplifying an audio analog signal output from the D / A converter 19 and a speaker 21 for converting the amplified audio analog signal into audio and outputting the audio to the outside.

In the present embodiment, in particular, the display 17
The system controller 5 and the graphic controller 14 each include a character data extracting unit, a map data converting unit, a character data converting unit, a synthesizing unit, and a display controlling unit. One example is configured, DVD-ROM disc D
An example of a recording medium is constituted by the K1 and the CD-ROM disk DK2.

(II) First Embodiment of Bird's-Eye View Display Process First, FIG. 2 shows a process in a main routine showing an overall operation in a first embodiment of the bird's-eye view display process by the navigation device S shown in FIG. This will be described with reference to a flowchart. In FIG. 2, the processing from step S1 to step S8 is executed by the CPU 7, and the operation from step S9 to step S12 is executed by the graphic controller 14.

The program corresponding to the flowchart in the present embodiment is a DVD-ROM disc DK1, a CD-ROM
It is stored in advance in the disk DK2 or the ROM 8, and if necessary, the DVD-ROM drive 12a or the CD-R
It is read out via the OM drive 12b or directly from the ROM 8.

First, the processing shown in FIG. 2 is started by shifting from a predetermined main navigation program to the processing shown in FIG. 2 when an instruction to display a map in a bird's eye view is input in the input device 11. .

When the processing shifts from the predetermined main navigation program to the processing shown in FIG. 2 according to the bird's-eye view display instruction, first, it is determined whether or not a set route as a scheduled route from the current position to the destination is set and stored in the RAM 9. Is determined (step S1). If the set route has been set (step S1; YES), the sight line direction in the bird's-eye view conversion (hereinafter, referred to as the display azimuth) sets the set route so that the set route is displayed farther away. Then, in consideration of the calculated display direction and the current position of the vehicle, map data (characters such as point names) including the current position and indicated by the display direction are calculated in consideration of the calculated display direction and the current position of the vehicle (step S2). DVD)
-ROM disk DK1 or CD-ROM disk DK
2 to DVD-ROM drive 12a or CD-ROM
The data is read out via the drive 12b and temporarily stored in the RAM 9 (step S3).

On the other hand, if the set route has not been set (step S1; NO), the traveling direction is calculated as the above-described display orientation in consideration of the current position of the vehicle and the current traveling direction (step S4). Next, map data (including character data such as point names) in the direction including the current position and indicated by the display direction (traveling direction) is transmitted from the DVD-ROM disk DK1 or the CD-ROM disk DK2 to the DV.
D-ROM drive 12a or CD-ROM drive 1
2b, and is temporarily stored in the RAM 9 (step S5).

When the necessary map data is stored in the RAM 9 (step S3 or S5), the character data (point name, famous facility name, road name, etc.) included in the map data is stored from the stored map data. , And a graphic representing a map symbol of a school, a police station, a factory, etc., and a graphic representing an index (landmark) representing a convenience store, a gas station, etc.) are extracted (step S6). Then, the map data excluding the character data (including only a road map, a background map, and the like).
Is viewed from one point in the sky near the current position of the vehicle to perform one-point perspective projection conversion (hereinafter simply referred to as bird's-eye view conversion).
Then, bird's-eye map data is generated and temporarily stored in the RAM 9 (step S7). Details of the processing in step S7 will be described later.

Next, the character data extracted in step S6 is subjected to bird's eye view conversion or pseudo bird's eye view conversion described later using the same method as in step S7 to generate bird's eye character data or pseudo bird's eye character data. It is stored in the RAM 9 (step S8). Details of the processing in step S8 will also be described later.

Subsequently, the stored bird's-eye map data, bird's-eye character data and pseudo bird's-eye character data are combined to generate one piece of map image data to be displayed on the display 17 (step S10). An image corresponding to information such as the current position index corresponding to the current position of the vehicle calculated by the CPU 7 and the distance to the destination on the set route is converted into image data (step S11). The data (step S10) and the image data (step S11) are temporarily stored in the buffer memory 15, and the process returns to the original main navigation program.
Thereafter, the map image data and the image data are read from the buffer memory 15 at the timing controlled by the display control unit 16, and the corresponding bird's-eye view map is displayed on the display 17.

(II-1) Detailed Processing for Generating Bird's-Eye Map Data Next, detailed processing for generating bird's-eye map data in step S7 will be described with reference to FIGS.

First, the bird's-eye view (one-point perspective projection) itself will be described in more detail with reference to FIG.

As shown in FIG. 3, the bird's-eye view is (X, Y,
Z) Point the map ABCD area expressed on the (X, Y) plane on the coordinate axis from the viewpoint E (Xo, Yo, Zo) to the reference point B (Xb, Yb, 0) on the (X, Y) plane. This is an image obtained by projecting an image looked down at a depression angle θ onto a viewing plane G arranged perpendicular to the line of sight. At this time, the direction of the line of sight from the viewpoint E has an angle α with respect to the X axis in the XY plane. That is, the angle α is the display orientation calculated in step S2 or step S4.

Further, the distance between the viewpoint E and the viewing plane G is denoted by Vd. Then, the center line (vertical line) in the viewing plane G is set as a reference line, and a predetermined point Q on the reference line is set as a reference point in one-point perspective projection. That is, the reference point Q is a point on a straight line connecting the viewpoint E and the reference point B when considered as an XY plane on the map.

Next, details of the bird's-eye view map data generation processing executed in step S7 will be described with reference to the flowchart shown in FIG. 4 and FIG. In the bird's-eye map data generation process, a method of setting the current position Po of the vehicle to a viewpoint position (a leg of a perpendicular line lowered from the viewpoint E to the map (on the (X, Y) plane)) and a method of setting the current position Po to Although there is a method of setting the reference point Q, there is no fundamental difference between the two. Here, for the sake of clarity of explanation, the current position Po is the reference point Q, and the reference point Q is the reference point B. A description will be given of a case where the values match.

As shown in FIG. 4, in step S7, first, the current position Po is set as the reference point Q and the reference point B (step S71), and then the height h of the viewpoint E is set.
Is input from the input device 11, the depression angle θ is calculated based on the input, and the display orientation α is read out (step S72). Next, the viewpoint E (Xo, Yo, Z
The coordinates of o) are calculated by the following equation with reference to the reference point B (Xb, Yb, 0) (step S73).

Xo = Xb−h × cosα / tan θ Yo = Yb−h × sinα / tanθZo = h Next, a bird's-eye view conversion is performed on the map data based on the coordinates of the viewpoint E calculated above (step). S74). In step S74, an arbitrary point M (M
x, My, Mz) to the corresponding point S on the viewing plane G
When performing coordinate transformation to (Sx, Sy), the following [Equation 1]
The following relational expression (determinant) is used.

[0060]

(Equation 1) In the above [Equation 1], “Ex”, “Ey” and “Ez” are three-dimensional displays of the point M viewed from the starting point E (the starting point E
Display value that also takes into account the depth from
After the coordinates of the point M are once converted into coordinates indicated by "Ex", "Ey" and "Ez", the viewing plane G is used by using these.
The transformation to the upper point S has been performed.

Then, for one point M, the point S (Sx,
Sy) (Sz is omitted because it is originally zero). When all points M on the map data to be converted are calculated, the corresponding points S on the viewing plane G are similarly converted. After the coordinate conversion is performed and the coordinate conversion for all points M is completed, they are stored in the RAM 9 and the process proceeds to step S8 (step S75). With the above operation, the bird's-eye view conversion of the map data not including the character data is completed.

Next, details of the bird's-eye character data and pseudo bird's-eye character data generation processing executed in step S8 of FIG. 2 will be described below for each example.

(II-2) First Example of Detailed Processing of Generating Bird's-Eye Character Data and Pseudo Bird's-Eye Character Data First, a first example of detailed processing of generating bird's-eye character data and pseudo-bird's-eye character data (step S8) This will be described with reference to the flowchart shown in FIG. In the first example described below, the character data is stored in a DVD-ROM disc DK1 or CD-RO as a so-called vector font.
This explains the bird's-eye view conversion process and the pseudo bird's-eye view conversion process when stored in the M disk DK2. Here, a vector font refers to a font in which a straight line forming one character or symbol is represented by start point coordinates indicating its start point and end point coordinates indicating its end point. More specifically, for example, the vector font indicating the character “not” includes the start point coordinates and the end point coordinates indicating the respective horizontal lines or vertical lines as relative coordinates with respect to a predetermined reference point. . For oblique lines or curves in characters, etc.,
The vector font is represented as a combination of horizontal lines or vertical lines, and includes a start point coordinate and an end point coordinate of the horizontal line or vertical line to form a diagonal line or a curve.

As shown in FIG. 5, in the first example of generating bird's-eye character data and pseudo bird's-eye character data, first,
One unprocessed character data is obtained from the extracted character data (step S20). Next, the input device 1 determines whether or not to highlight the character data on the display 17.
The determination is made based on the user's instruction from Step 1 (Step S21). The emphasized display in step S21 means that the character data is emphasized and displayed on the display 17 so that it can be distinguished from other character data. In the present embodiment, if the name is emphasized in step S21, As described below, character data related to the set route (for example, name data indicating an intersection on the set route or name data indicating a target feature on the set route) is highlighted.

If it is determined in step S21 that the name is to be emphasized (step S21; YES), it is next determined whether or not the set route has been set up to the present and stored in the RAM 9 (step S22). ). If the set route exists (step S22; Y
ES) Next, it is determined whether or not the character data acquired in step S20 is character data related to the set path (step S23).

If it is determined in step S23 that the character data is related to the set route (step S23; YES), a predetermined emphasis process is performed on the character data (step S24). The emphasizing process in step S24 includes, for example, a process of converting the character data to be emphasized to a color different from that of other character data, or a process of framing the character data to be emphasized. Done.

The emphasis processing (step S24) ends.
And then display the character data to be converted to the bird's-eye view
The depression angle θ at the point (see FIG. 3)
Limit value θ _LIt is determined whether or not this is the case (step S2).
5). Here, the depression angle θ is set at each point as shown in FIG.
Is calculated from the height of the viewpoint E and the like.
Also, the lower limit θ_LIs 0 ° <θ_L<90 ° range
It can be set to any value, for example, a value such as 45 °
Is set to

In step S25, the depression angle θ is set to the lower limit value θ.
_{If L} or more (YES), using the depression angle θ, [Equation 1] similar to the bird's-eye map data generation processing shown in FIGS. 3 and 4 is used for the character data to be converted to the bird's-eye view. Bird's-eye view conversion (that is, bird's-eye view conversion performed on the coordinates of the start point and end point in each line segment constituting the character data as a vector font) is performed, and the character data is converted for bird's-eye view display and stored in the RAM 9 ( Step S26-1).

On the other hand, if the depression angle θ is smaller than the lower limit value θ _L in step S25 (NO), the lower limit value θ _L is used to move forward according to the horizontal distance from the viewpoint E to the point where character data is displayed. Based on the shifted viewpoint different from the original viewpoint E, the same [Equation 1] as in the bird's-eye map data generation processing shown in FIGS. 3 and 4 is used for the character data to be converted into the bird's-eye view. Bird's-eye view conversion, that is, pseudo bird's-eye view conversion is performed. As a result, the character data is converted into a pseudo bird's-eye view display and stored in the RAM 9 (step S26-2). About this pseudo bird's-eye view conversion, FIGS.
This will be further described with reference to FIG.

[0070] Figure 6 is a diagram schematically showing the plane containing the Z axis and the reference line geometric drawing of FIG. 3, as shown in FIG. 6, the lower limit is depression angle theta relative to the viewpoint E theta _L At the points Pa,..., And Pb, the depression angle θ of each point is determined by the viewpoint E in the bird's-eye view conversion as described with reference to FIGS.
(X ₀ , Y ₀ , Z ₀ ) and a point S (Sx, S
y) is used as it is as a depression angle (hereinafter referred to as depression angle θ ′) used when each is determined (θ ′ = θ). On the other hand, at points Pc,..., Pd where the depression angle θ is less than the lower limit θ _L ,
The lower limit θ _L is used as the depression angle θ ′ (θ ′ =
θ _L ). That is, in the latter case, based on a viewpoint E ′ different from the original viewpoint E, which is shifted forward according to the horizontal distance from the viewpoint E to the point where the character data is displayed,
The pseudo bird's eye view conversion is performed on the character data to be converted. As a result, at the points Pa,..., Pb, the characters displayed according to the distance from the viewpoint E are, for example, as shown in FIG.
As shown in the example of the character 100a → the character 100b, crushing in the vertical direction increases. On the other hand, at points Pc,..., Pd where the depression angle θ has reached the lower limit value θ _L , the viewpoint E ′ is also shifted to the far side according to the horizontal distance from the viewpoint E, and the depression angle θ ′ = θ _L (fixed). Since a pseudo bird's eye view conversion is performed,
The displayed characters are the characters 100 also illustrated in FIG.
The collapse in the vertical direction does not increase as in the case of c → character 100d (that is, character 100c and character 100d have the same size and shape).

FIG. 7 shows the depression angle θ of each point with respect to the viewpoint E.
A characteristic diagram shows the relationship between the angle of depression θ ′ actually used for bird's-eye view conversion (pseudo bird's-eye view conversion) for character display. As is clear from FIG. 7, at a point where the depression angle θ is larger than the lower limit value θ _L (on the near side as viewed from the viewpoint), the depression angle θ is used as it is for bird's-eye view conversion for both map display and character display. However, at points where the depression angle θ is smaller than the lower limit value θ _L (far away from the viewpoint), the depression angle θ is used as it is for map display, but for character display, the lower limit value θ _L is used for conversion. It is used as the depression angle θ ′.

In the example of FIG. 6, each viewpoint E 'is placed on the same horizontal plane as the viewpoint E, and the bird's eye view conversion (pseudo bird's eye view conversion) is performed based on each viewpoint E'. As shown, each viewpoint E ′ may also be shifted in the vertical direction according to the distance from each corresponding point to viewpoint E.

In FIG. 8, since the distance from each viewpoint E 'to each corresponding point Pc,..., Pd is set equal to the distance from the bird's-eye view point E to each point Pc,. The character displayed at the point Pc and the character displayed at the point Pd are the character 100c ′ and the character 1 illustrated in the figure.
Like 00d ', the shapes are the same but the sizes are different (even though they are squashed in the vertical direction, the size of the whole character becomes smaller as it goes farther).

As described above, in the case of the pseudo bird's-eye view conversion shown in FIG. 6, when the depression angle θ reaches the lower limit value θ _L , not only the upper and lower squashing of character data displayed at a further distant point is the same, but also Since the same size is displayed, it is convenient to properly set the lower limit value θ _L so that character data located at a distant position can be reliably read. On the other hand, in the case of the pseudo bird's-eye view conversion shown in FIG. 8, when the depression angle θ reaches the lower limit value θ _L , the character data displayed at a point farther away is the same in the vertical collapse manner and the size depends on the distance. Since the character data is displayed differently, it is possible to express the perspective of character data displayed in a distant place by using the size of the character data, and to obtain an advantage that character data adjacent to a distant place can be prevented from overlapping.

The pseudo bird's-eye view conversion that can be adopted in the present embodiment is not limited to the bird's-eye view conversion in which the viewpoint E is shifted to the viewpoint E ', and the lower limit value θ _L
The character data displayed at a point farther than the point at which the character has reached the point may be converted into a drafting that can more or less express a stereoscopic effect such as a perspective view or a two-point perspective projection view. In short, it is sufficient for the character data displayed small in a distant place to be large enough to be easily read, and to appear to be slightly inclined toward the distant place. Further, in the example of FIG. 6 and FIG. 8 has been described for the conversion of a plane including a reference line, for the point is not on the reference line as shown in the perspective view of FIG. 9, the depression angle theta is the lower limit theta _L If it is larger, it is used as it is for bird's-eye view conversion, and the depression angle θ is set to the lower limit θ _L
If less than, be for use in pseudo-bird's eye view converting the lower limit theta _L as depression angle theta '. In this case as well, FIG.
Alternatively, any one of the pseudo bird's-eye view conversion methods shown in FIG. 8 or a combination thereof may be used, or a conversion method to another perspective view or the like may be adopted. As a result, as illustrated in FIG. 9, for each point where the depression angle θ ′ is fixed to the lower limit value θ _L both on the reference line and in an area deviating from the reference line,
Pseudo bird's-eye characters 101 to 103 having a shape corresponding to the azimuth and not being crushed up and down too much are obtained.

As described above, the depression angle θ is set to the lower limit value θ._LUntil
Then, as the characters go away,
Limit value θ_LIs the resolution of the display 17 and the height of the viewpoint E
Various parameters such as the size and type of character data to be used
The lower limit value θ according to the meter _LBird's-eye view
Even if figure conversion or pseudo bird's eye view conversion is performed, the converted characters
Predetermined as an angle that can be easily read on the display screen
It is desirable that Such lower limit value θ_LIs a professional
May be fixed by the gram,
Automatically set as a predetermined function of the above various parameters
And the user may input through the input device 11.
May be settable.

Referring again to FIG. 5, if no name emphasis is applied to any of the character data in step S21 (step S21; NO), step S25 is performed in order to convert all the character data into a bird's eye view or a pseudo bird's eye view in the same manner. Move to

In step S22, even when name emphasis is performed, if no set path is set (step S22; NO), there is no character to be emphasized, so that all character data is similarly processed. The process proceeds to step S25 to perform bird's eye view conversion or pseudo bird's eye view conversion.

Further, in step S23, if the acquired character data is not related to the set route even if the set route is set (step S23; NO), step S2 is performed to convert the bird's eye view or the pseudo bird's eye view as it is.
Move to 5.

When the bird's eye view conversion or the pseudo bird's eye view conversion is completed for the target character data (step S26-1)
Or 26-2), it is determined whether the processing has been completed for all the character data to be converted stored in the RAM 9 (step S27), and when the processing has been completed (step S27; YES). Then, the process proceeds to the process of step S9 in FIG.

On the other hand, if it is determined in step S27 that the bird's-eye view processing has not been completed for all the character data (step S27; NO), the process proceeds to step S20 to acquire character data for which processing has not been completed. The above steps are repeated for the character data. With the above operation, the bird's-eye view conversion and the pseudo bird's-eye view conversion of the character data are completed.

Steps S7 and S described above
When the bird's-eye view display processing shown in FIG. 2 including the processing of No. 8 (first example of generation of bird's-eye character data and pseudo bird's-eye character data) is completed, an image displayed on the display 17 as a result is, for example, shown in FIG. As described above, character data such as a spot name is displayed in a bird's eye view along with the road map and the background.

In particular, in the example of FIG. 10, for the characters 201 of "Miyasakazaka", the characters 202 of "Uchibori-dori", and the characters 203 of "Yotsuya" displayed at relatively distant points, the depression angle θ of each point is as being less than the lower limit theta _L, results pseudo bird's-eye view conversion is applied to these character data, the three characters 201 to 203 are crushed how vertically is displayed to be the same, all characters It can be said that it is not easy to read because it is crushed up and down, and it is easy to read. In addition, although these characters slightly rise up diagonally from the plane showing the ground toward the front, they have fallen sufficiently far away, and together with maps other than the characters that are completely bird's-eye views, there is a sense of presence and perspective. It helps to express the feeling.

(II-3) Second Example of Detailed Processing of Generating Bird's-Eye Character Data and Pseudo Bird's-Eye Character Data Next, a second example of detailed processing of generating bird's-eye character data and pseudo-bird's-eye character data (step S8) will be described. 11
This will be described with reference to the flowchart shown in FIG. The second example described below describes a bird's eye view conversion process when character data is stored as a so-called image font on a DVD-ROM disk DK1 or CD-ROM disk DK2. here,
The image font does not include one character or symbol as coordinates for each line segment as in the above-described vector font, but the entire character or symbol as one image data as a pixel (dot) on the display 17. Are represented as a set of

In the following description of the second example, the same processes as those in the flowchart shown in FIG. 5 are denoted by the same step numbers, and detailed description is omitted.

As shown in FIG. 11, in the second example of the generation of the bird's-eye character data and the pseudo bird's-eye character data, first, the operations shown in steps S20 to S24 shown in FIG. 5 are executed.

When character data to be displayed in the bird's-eye view is determined (step S21; NO, step S22).
NO, step S23; NO or step S24), and then the number of display characters in one name and the like and the display direction α
Then, an area for storing character data (image font) before bird's-eye view conversion is calculated based on (step S30).

Here, regarding the operation of step S30,
More specifically, with reference to FIG. 12A, before the image font is converted to the bird's-eye view, the image font shown in FIG.
As shown in FIG. 12, the lower left end of the display screen of the display 17 (the point indicated by (0, 0) in FIG. 12A)
In the case of one drawing point (FIG. 12A) (16
0, 120)) and a font size (character size; in FIG. 12A, the character size of two characters) based on the drawing point, the drawing area of the character data is determined. . Note that the coordinates of the drawing points at the four corners of the drawing area shown on the right side of FIG. 12A are the drawing point coordinates when the font size corresponding to one character is composed of 16 × 16 pixels. Based on the above-described method for determining the drawing area, in step S30, the coordinates of each drawing point in the drawing area before bird's-eye view conversion are calculated based on the number of characters in the place name to be displayed and the display direction α.

When the coordinates of each drawing point in the drawing area before the bird's-eye view conversion is calculated (step S3)
0) Next, it is determined whether or not the depression angle θ (see FIG. 3) at the point where the character data to be converted to the bird's eye view is displayed is equal to or greater than a preset lower limit value θ _L (step S).
31).

In step S31, the depression angle θ is set to the lower limit value θ.
_{If L} or more (YES), this depression angle θ is used as it is, and [Formula 1] similar to the bird's-eye view map data generation processing shown in FIGS. 3 and 4 is used for the drawing points at the four corners of the drawing area. A bird's-eye view conversion is performed, and a drawing area 301 converted into a bird's-eye view as shown on the right side of FIG. 12B is calculated. Based on the calculated drawing area 301, the image font of the character itself is set so as to fit in the area. Is written in the drawing area 301 (step S32-1). When the processing in step S32-1 is completed, the bird's eye view converted character data as shown on the right side of FIG. 12B is completed in the drawing area 301, and is stored in the RAM 9.

On the other hand, if the depression angle θ is smaller than the lower limit value θ _L in step S31 (NO), the lower limit value θ _L is used to determine a reference point different from the original viewpoint E as in the first example. Similar to the bird's-eye view map data generation processing shown in FIGS. 3 and 4 for the drawing points at the four corners of the drawing area [Equation 1]
Is performed (see FIG. 6 to FIG. 9). As a result, a drawing area 302 converted into a pseudo bird's eye view as shown on the right side of FIG.
Based on the calculated drawing area 302, the image font of the character itself is transformed into the area and written into the drawing area 302 (step S32-).
2). When the process of step S32-2 ends, FIG.
(B) Since the character data converted into the pseudo bird's eye view as shown on the right side is completed in the drawing area 302, this is stored in the RAM.
9 is stored.

Thereafter, the process of step S27 shown in FIG. 5 is executed, and thereafter, the flow shifts to step S9 of FIG.
As a result, as shown in FIG. 12 (b), the character 301a, which is relatively short, is displayed on the bird's-eye map as a bird's-eye character, and the character 302a far away is displayed on the bird's-eye map as a pseudo bird's-eye character. Will be.

Step S7 and step S described above
When the bird's-eye view display processing shown in FIG. 2 including the processing of No. 8 (second example of generation of bird's-eye character data and pseudo bird's-eye character data) is completed, the image displayed on the display 17 as a result is also shown in FIG. As described above, character data such as a spot name is displayed in a bird's-eye view along with the road map and the background.

According to the above-described first embodiment of the bird's-eye view display processing, characters are converted to bird's-eye views at relatively short points (that is, points where the depression angle θ is equal to or larger than the lower limit θ _L ).
A bird's-eye view map other than text is combined and displayed. At the same time, relatively distant points (i.e., depression angle theta is less than the lower limit theta _L point) because characters for is pseudo bird's eye view of, are displayed in a combined in bird's eye view of the the map other than the character, the bird's-eye view of There is no inconvenience that the characters are too squashed up and down and cannot be read.

Further, since an index indicating the current position and the traveling direction of the vehicle is also displayed at the same time, the visibility and realism of the map near the current position of the vehicle and the names of the features on the display 17 are increased.

Further, since a bird's-eye view map including the set route is displayed, it is possible to display the terrain situation near the set route in a bird's-eye view with good visibility and realism.

Furthermore, in the case where characters near the set route are displayed in an emphasized manner, the name of a feature near the set route can be displayed with good visibility.

In the above-described embodiment of the bird's-eye view display processing, when the characters are emphasized, only the characters related to the set path are emphasized. However, the present invention is not limited to this, and is not related to the set path. It can also be configured to emphasize even characters. In that case, the above step S
Apart from the process 24, only the characters to be highlighted (irrelevant to the set path) are collectively emphasized, and then the bird's eye view is converted together with the characters related to the set path.

Further, in the above-described embodiment of the bird's-eye view display processing, only the character data is extracted from the map data including the character data, the remaining map data excluding the character data is converted into the bird's-eye view, and the character data is further converted into the bird's-eye view. Alternatively, the case where the pseudo bird's-eye view conversion is performed has been described. However, the present invention is not limited to this, and the bird's-eye view map data is generated by first converting the map data recorded separately from the character data into bird's-eye view data. -ROM disk DK1 or CD
-A bird's-eye view map or pseudo-bird's-eye view conversion by reading from the ROM disk DK2 to generate bird's-eye character data or pseudo bird's-eye character data, and finally combining these to obtain a bird's-eye view map may be adopted.

(III) Second Embodiment of Bird's Eye View Display Processing Next, a second embodiment of the bird's eye view display processing by the navigation device S shown in FIG. 1 will be described with reference to FIGS.

In the present embodiment, the bird's-eye view display processing is performed in substantially the same manner as in the flowchart of FIG. 2, but the bird's-eye character data or pseudo bird's-eye character data generation processing in step S8 is performed in accordance with the flowchart shown in FIG. Is different. In FIG. 13, the same steps as those in FIG. 5 are denoted by the same step numbers, and description thereof will be omitted.

In FIG. 13, as in FIG.
When the processing in steps S20 to S24 is performed, a depression angle θ ′ equal to an angle (gθ) obtained by multiplying the depression angle θ of each point displaying each character data by a predetermined gain value g is used for bird's-eye view conversion, and the vector font Conversion is performed (step S35). That is, in the first embodiment described above, as shown in FIG. 7, the depression angle θ ′ used for bird's-eye view conversion is θ ′ = θ or θ ′ = θ depending on the magnitude relationship between the depression angle θ of each point and the lower limit value θ _L. has been a theta _L, in the second embodiment, as shown in FIG. 14, theta '=
Bird's-eye view transformation using θ ′ calculated by g * θ (ie,
Pseudo bird's-eye view conversion) is performed.

Thereafter, step S27 is performed. When the above pseudo bird's-eye view conversion has been completed for all character data, the flow shifts to step S9 in FIG.

As described above, since characters are crushed as they go far, the gain value g depends on various parameters such as the resolution of the display 17, the height of the viewpoint E, and the size and type of character data to be used. Even if the pseudo bird's eye view conversion is performed with the angle (gθ) being the depression angle θ ′, it is desirable that the angle be set in advance so that the converted characters can be easily read on the display screen. Such a gain value g may be fixed by a program, may be automatically set by the program as a predetermined function of the above various parameters, or may be set by a user via the input device 11. It may be.

As a result, according to the second embodiment, the character data is displayed at each point, like a signboard provided diagonally along the ground, over the entire area of the displayed bird's-eye map. There is no inconvenience that the characters are too squashed up and down and cannot be read.

In the second embodiment, an example in which character data is composed of vector fonts as shown in FIG. 13 has been described as an example. However, the first embodiment will be described with reference to FIGS. 11 and 12. As described above, even when the character data is composed of an image font, steps S31 and S32-1 in FIG.
And the process of step S32-2, and using a depression angle θ ′ equal to an angle (gθ) obtained by multiplying the depression angle θ of each point displaying each character data by a predetermined gain value g in the pseudo bird's eye view conversion, to convert the image font May be configured to perform the conversion. Also in this case, the character data is displayed at each point like a signboard provided diagonally along the ground over the entire area of the displayed bird's-eye map, and the character is crushed up and down by the bird's-eye view and becomes unreadable. There is no inconvenience.

(IV) Modification of the Second Embodiment of the Bird's-Eye View Display Processing Next, a modification of the second embodiment of the above-described bird's-eye view display processing will be described with reference to FIG.

In this embodiment, the bird's-eye view display processing and the pseudo bird's-eye character data generation processing are performed in the same manner as in the second embodiment. However, in step S35 of FIG. 13, the depression angle θ of each point shown in FIG. Instead of a depression angle θ ′ equal to an angle (gθ) obtained by multiplying by a predetermined gain value g, a depression angle θ ′ equal to a predetermined function f (θ) of the depression angle θ is used for the pseudo bird's eye view conversion as shown in FIG. To convert the vector font. Here, the predetermined function f (θ) is θ
A function is set which decreases with decreasing. For example, various functions such as a power function of θ, an exponential / logarithmic function, and a cosine / sine function can be adopted.

When the conversion is performed as described above, the character is crushed as it goes farther, so that the predetermined function f (θ) becomes
According to various parameters such as the resolution of the display 17, the height of the viewpoint E, the size and type of character data to be used, etc., even if the f (θ) is set to the depression angle θ ′ and the pseudo bird's-eye view conversion is performed, Is desirably determined in advance so that can be easily read on the display screen. Such a predetermined function f (θ) may be fixed by a program, or the program may be automatically set as a predetermined function of the above various parameters.
May be settable by the user via the.

As a result, according to this modification, the character data is displayed at each point like a signboard provided diagonally along the ground over the entire area of the displayed bird's-eye map, and the character data is displayed by bird's-eye view. There is no inconvenience that can be read because it is crushed up and down too much. Also, depending on the contents of the function f (θ), the bird's-eye characters can be superimposed on the bird's-eye map at almost the same depression angle on the front side, and only characters at a distance that would be difficult to read when superimposed on the bird's-eye map are appropriately shifted from the bird's-eye map. This is convenient because it can be launched and displayed.

In this modification, the example in which the character data shown in FIG. 13 is composed of a vector font has been described as an example. However, as in the second embodiment, the character data is composed of an image font. Also in this case, the image font may be converted by using the depression angle θ ′ equal to the predetermined function f (θ) for the pseudo bird's-eye view conversion. Also in this case, there is no inconvenience that the characters are too crushed up and down due to the bird's-eye view and cannot be read.

(V) Third Embodiment of Bird's-Eye View Display Processing Next, a third embodiment of the bird's-eye view display processing by the navigation device S shown in FIG. 1 will be described with reference to the flowchart shown in FIG. This will be described with reference to FIG.

In the processing of this embodiment, when an instruction to display a map in a bird's-eye view is input to the input device 11, a predetermined main navigation program is used to execute the processing shown in FIG.
The process is started by shifting to the process shown in FIG.

In the above-described embodiments of the bird's-eye view display processing, the case where the character data can be separated from the map data other than the character data as a vector font or an image font has been described.
-ROM disk DK1 or CD-ROM disk DK
2 is a bird's-eye view in which the character data and the map data other than the character data cannot be separated because the character data and the map data other than the character data are integrally recorded as image data (image data). It shows a conversion process.

In the following description, the same processes as those in the flowchart shown in FIG. 2 are denoted by the same step numbers, and detailed description is omitted.

Further, in the flowchart shown in FIG. 16A, the processing of steps S1 to S5 and S40 is
The processing is executed in PU7, and steps S41 and S11
And the processing of S12 is executed by the graphic controller 14.

In the third embodiment of the bird's-eye view display processing, first, steps S1 to S5 shown in FIG.
Is performed.

When the necessary map data (in which the character data is integrated) is stored in the RAM 9 (step S3 or S5), next, each drawing point constituting the image data including the character data is set. On the other hand, bird's-eye view conversion or pseudo-bird's-eye view conversion using [Equation 1] similar to that described in FIGS. 3 and 4 and FIGS. 6 to 9 is performed to generate bird's-eye view data or pseudo bird's-eye view data (step S40). The bird's-eye view data and the pseudo bird's-eye view data are converted into map image data (step S41). Thereafter, the processes shown in steps S11 and S12 in FIG. 2 are executed, and the process returns to the original main navigation program.

In the processing described above, step S40
In the processing shown in FIG. 16B, as shown in FIG. 16 (b), the image data before bird's-eye view conversion is relatively near to the front side (that is, the depression angle θ is equal to or more than the lower limit value θ _L ) while including characters. is the bird's-eye view conversion, relatively is in the far (i.e., depression angle theta is less than the lower limit theta _L) for the point is the pseudo-bird's eye view transformation, and be subsequently displayed.

According to the processing of the third embodiment described above,
Even when the character data is recorded as image data integrally with the map data other than the character data, FIG.
A bird's-eye view display similar to 0 can be obtained.

(VI) Fourth Embodiment of Bird's Eye View Display Processing Next, a fourth embodiment of the bird's eye view display processing by the navigation device S shown in FIG. 1 will be described.

In the present embodiment, the bird's-eye view display process is performed in substantially the same manner as in the flowchart of FIG. 16, but the process of converting image data including characters into a bird's-eye view in step S40 is the same as that of the second embodiment shown in FIG. This is performed in the same manner as in step S35.

That is, in the third embodiment, the depression angle θ ′ of θ ′ = θ or θ _L is used for the conversion in accordance with the magnitude relationship between the depression angle θ of each point and the lower limit value θ _L. Then, Figure 1
As shown in FIG. 4, the pseudo bird's-eye view conversion is performed using the depression angle θ ′ calculated by θ ′ = g * θ.

As a result, according to the fourth embodiment, it is possible to display a pseudo bird's-eye view that is slightly upwardly curved toward the far side as compared to the bird's-eye view. There is no inconvenience that can not be read.

(IV) Modification of Fourth Embodiment of Bird's-Eye View Display Processing Next, a modification of the fourth embodiment of the above-described bird's-eye view display processing will be described.

In the present embodiment, the bird's-eye view display processing is performed in the same manner as in the fourth embodiment. However, as in the case of the modification of the second embodiment, a predetermined gain value g is added to the depression angle θ at each point. Instead of the depression angle θ ′ equal to the angle (gθ) obtained by the multiplication, a predetermined function f of the depression angle θ as shown in FIG.
The conversion is performed using a depression angle θ ′ equal to (θ).

As a result, according to the present modified embodiment, a pseudo bird's-eye view curved slightly upward toward the far side as compared with the bird's-eye view can be displayed. There is no inconvenience.

[0128]

As described above in detail, according to the map display control device of the first aspect, the character located relatively near is directly converted into the bird's-eye view using the depression angle θ, and the character converted into the bird's-eye view is obtained. Characters located relatively far away are converted to a pseudo bird's-eye view using the lower limit value θ _L , and combined with a map other than a bird's-eye view character to be displayed. Therefore, the same number of characters can be displayed in a relatively near area as when a character as a plan view is combined with a map as a plan view. Furthermore,
Since the map other than the bird's-eye view characters and the corresponding bird's-eye view or pseudo bird's-eye view characters are simultaneously displayed, the visibility and the sense of reality on the display screen are increased. At the same time, it is possible to effectively prevent characters in a relatively distant area from being squeezed up and down due to the bird's-eye view and becoming difficult to read.

According to the map display control device of the present invention, a map other than a character is converted into a bird's-eye view, and the character has a depression angle equal to the angle (gθ) obtained by multiplying the depression angle θ of each point by a predetermined gain value g. It is converted to a pseudo bird's eye view using θ '. Furthermore,
Since the map other than the bird's-eye view character and the corresponding pseudo bird's-eye view character are simultaneously displayed, the visibility and the sense of reality on the display screen are increased. At the same time, it is possible to effectively prevent characters in a relatively distant area from being squeezed up and down due to the bird's-eye view and becoming difficult to read.

According to the map display control device of the third aspect, a map other than a character is converted into a bird's-eye view, and the character is simulated using a depression angle θ ′ equal to a predetermined function f (θ) of the depression angle θ at each point. Since it is converted to a bird's-eye view, the visibility and realism on the display screen are increased, and it is possible to effectively prevent characters from being crushed up and down by a bird's-eye view and making it difficult to read even in relatively distant areas Becomes

According to the map display control device of the fourth aspect, the map including the character located relatively in front is formed by the depression angle θ.
Is converted to a bird's-eye view as it is and displayed. Also,
Map, including the character located relatively far is displayed is converted to a pseudo bird's eye view using the lower limit theta _L. Therefore, the display map is composed of the part including the character that is formed into a bird's-eye view that spreads relatively forward and the part that includes the character that is formed into a pseudo bird's-eye view that spreads relatively far, so that the visibility and the sense of presence are increased. You. At the same time, it is possible to effectively prevent characters in a relatively distant area from being squashed up and down due to the bird's-eye view and becoming difficult to read.

According to the map display control device of the fifth aspect, the map including the characters uses a depression angle θ ′ equal to an angle (gθ) obtained by multiplying the depression angle θ of each point by a predetermined gain value g. It is converted to a pseudo bird's eye view. Furthermore, since the map including the characters in the pseudo bird's eye view is displayed, the visibility and the sense of reality are increased. At the same time, it is possible to effectively prevent characters in a relatively distant area from being squeezed up and down due to the bird's-eye view and becoming difficult to read.

According to the map display control device of the sixth aspect, the map including the characters is formed by the predetermined function f of the depression angle θ of each point.
(Θ) is converted to a pseudo bird's-eye view using a depression angle θ ′ equal to (θ), so that the visibility and the sense of presence on the display screen are increased, and even in relatively distant areas, characters are crushed up and down by the bird's-eye view and read. It becomes possible to effectively prevent the difficulty.

According to the recording medium described in claim 7, the map display control device described in claim 1 can be realized using a computer.

According to the recording medium of the eighth aspect, the map display control device of the second aspect can be realized using a computer.

According to the recording medium of the ninth aspect, the map display control device of the fourth aspect can be realized by using a computer.

According to the recording medium of the tenth aspect, the map display control device of the fifth aspect can be realized using a computer.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a vehicle navigation device according to an embodiment.

FIG. 2 is a flowchart illustrating an overall operation of a bird's-eye view display process according to the first embodiment.

FIG. 3 is a diagram illustrating bird's-eye view conversion.

FIG. 4 is a flowchart illustrating a bird's-eye view conversion process.

FIG. 5 is a flowchart illustrating a first example of bird's-eye character data generation processing according to the first embodiment.

FIG. 6 is a conceptual diagram illustrating an example of a process of generating pseudo bird's-eye character data according to the first embodiment.

FIG. 7 is a characteristic diagram illustrating a process of generating pseudo bird's-eye character data according to the first embodiment.

FIG. 8 is a conceptual diagram for describing another example of a process of generating pseudo bird's-eye character data according to the first embodiment.

FIG. 9 is a diagram illustrating a process of generating pseudo bird's-eye character data according to the first embodiment.

FIG. 10 is a diagram illustrating an example of an execution result of a bird's-eye view display process.

FIG. 11 is a flowchart illustrating a second example of bird's-eye character data generation processing according to the first embodiment.

12 is a diagram showing a bird's-eye view conversion when character data is an image font in the process shown in FIG. 11, (a) is a diagram showing a drawing area in the image font, and (b) is a bird's-eye view It is a figure showing an image font.

FIG. 13 is a flowchart illustrating bird's-eye character data generation processing according to the second embodiment.

FIG. 14 is a characteristic diagram illustrating a process of generating pseudo bird's-eye character data according to the second embodiment.

FIG. 15 is a characteristic diagram illustrating a process of generating pseudo bird's-eye character data according to a modification of the second embodiment.

16A and 16B are diagrams illustrating a bird's-eye view display process according to the third embodiment, in which FIG. 16A is a flowchart illustrating an overall operation of the bird's-eye view display process, and FIG. 16B illustrates a bird's-eye view conversion of image data including character data. FIG.

FIG. 17 is a diagram showing an outline of bird's-eye view conversion.

FIG. 18 is a diagram illustrating an example of a bird's-eye view display.

FIG. 19 is a diagram showing an example of character display in a conventional bird's-eye view display.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Acceleration sensor 2 ... Angular velocity sensor 3 ... Driving distance sensor 4 ... GPS receiver 5 ... System controller 6 ... Interface 7 ... CPU 8 ... ROM 9 ... RAM 10 ... Bus line 11 ... Input device 12a ... DVD-ROM drive 12b ... CD -ROM drive 13 ... Display unit 14 ... Graphic controller 15 ... Buffer memory 16 ... Display control unit 17 ... Display 18 ... Sound reproduction unit 19 ... D / A converter 20 ... Amplifier 21 ... Speaker S ... Navigation device

Claims (10)

[Claims] 1. A map is displayed by a display means to display a moving object.
The display means in a navigation device for assisting movement
Display control device for controlling the display of the map by the
And characters corresponding to characters from map data corresponding to the map.
Character data extracting means for extracting data, the map data not including the character data,
One-point see-through of the terrain corresponding to the data from one point in the air
Convert to a bird's eye view, which is a visual projection map, and output bird's eye map data
Map data converting means, and the one point in the air among the extracted character data is used as a reference.
Given lower limit θ _L(However, 0 ° <θ_L<90 °)
The one corresponding to the point with the upper depression angle θ
Each time, output bird's-eye character data, and extract
Of the extracted character data with reference to the one point in the air.
Lower limit value θ_LCorresponding to a point with a depression angle θ less than
The lower limit θ_LBird's-eye view seen through at a depression angle θ 'equal to
Character data that is converted to
Data conversion means, and the outputted bird's-eye character data and pseudo bird's-eye character data
And the outputted bird's-eye character data and pseudo bird's-eye character data
The output bird's-eye map data corresponding to the data
Synthesizing means for generating synthetic bird's-eye view data; and a synthetic bird's-eye view corresponding to the generated synthetic bird's-eye view data.
Display control means for displaying on the display means.
A map display control device characterized by the above-mentioned. 2. A map display control device for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting movement of a moving body, the map corresponding to the map. Character data extraction means for extracting character data corresponding to characters from the data, the map data not including the character data, a bird's-eye view which is a one-point perspective projection view in which the terrain corresponding to the map data is viewed from one point in the air. A map data converting means for converting and outputting the bird's-eye map data; and converting the extracted character data to a predetermined gain value g (provided that the depression angle θ with respect to the point in the air at a point corresponding to the character data has a reference). , 1 <g) and the angle (g)
θ), a character data conversion means for converting each into a pseudo bird's-eye view perspectiveed at a depression angle θ ′ and outputting pseudo bird's-eye character data, and corresponding to the output pseudo bird's-eye character data and the output pseudo bird's-eye character data Combining means for combining the outputted bird's-eye view map data to generate combined bird's-eye view data, and display control means for displaying a combined bird's-eye view corresponding to the generated combined bird's-eye view data on the display means. A map display control device characterized by the above-mentioned. 3. The character data conversion means, instead of the angle (gθ), a predetermined function f (θ) of the depression angle θ (where 0 ° <f (θ) <90 °, f (θ) is 3. The map display control device according to claim 2, wherein the map is converted into a pseudo bird's-eye view perspectiveed at a depression angle θ ′ equal to a function that decreases as θ decreases. 4. A map display control device for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting movement of a moving body, wherein the map display control device corresponds to the map and Corresponding to a point having a depression angle θ of a predetermined lower limit θ _L (0 ° <θ _L <90 °) or more with reference to one point in the air among map data including character data corresponding to characters in the map. The part is converted into a bird's-eye view, which is a one-point perspective projection view of the terrain corresponding to the map data from one point in the air, and bird's-eye view data is output, and the lower limit value is set based on the one point in the air in the map data. convert the portion corresponding to the point having the depression angle theta is less than theta _L pseudo bird's eye view obtained by transmission at depression angle theta 'equal to said lower limit theta _L, a map data converting means for outputting a pseudo bird's-eye view data, the output Map display control apparatus characterized by comprising a display control means for displaying on said display means the bird's-eye view corresponding to the bird's-eye view data and pseudo bird's-eye view data. 5. A map display control device for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting movement of a moving object, wherein the map display control device corresponds to the map and The map data including the character data corresponding to the characters in the map is converted into a predetermined gain value g (where 1 <
g) is converted to a pseudo bird's-eye view perspectiveed at a depression angle θ ′ equal to the angle (g θ) obtained by multiplying the obtained bird's-eye view data corresponding to the pseudo bird's-eye view data output. A map display control device, comprising: a display control means for displaying on the display means. 6. The map data conversion means, instead of the angle (gθ), a predetermined function f (θ) of the depression angle θ (where 0 ° <f (θ) <90 °, f (θ) is 6. A map display control device according to claim 5, wherein the map is converted into a pseudo bird's-eye view perspectiveed at a depression angle θ ′ equal to a function that decreases as θ decreases. 7. A moving object is displayed by displaying a map by a display means.
The display means in a navigation device for assisting movement
Computer for controlling the display of the map by
The map display control device obtains characters corresponding to characters from map data corresponding to the map.
A character data extraction procedure for extracting data, the map data not including the character data,
One-point see-through of the terrain corresponding to the data from one point in the air
Convert to a bird's eye view, which is a visual projection map, and output bird's eye map data
A map data conversion procedure to be performed, and referring to the one point in the air among the extracted character data.
Given lower limit θ _L(However, 0 ° <θ_L<90 °)
The one corresponding to the point with the upper depression angle θ
Each time, output bird's-eye character data, and extract
Of the extracted character data with reference to the one point in the air.
Lower limit value θ_LCorresponding to a point with a depression angle θ less than
The lower limit θ_LBird's-eye view seen through at a depression angle θ 'equal to
Character data that is converted to
Data conversion procedure, and the outputted bird's-eye character data and pseudo bird's-eye character data
And the outputted bird's-eye character data and pseudo bird's-eye character data
The output bird's-eye map data corresponding to the data
And a synthesis procedure for generating synthetic bird's-eye view data, and a synthetic bird's-eye view corresponding to the generated synthetic bird's-eye view data.
And a display control procedure to be displayed on the display means.
Computer with map display control program for
Data readable recording medium. 8. A map display control device including a computer for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting movement of a moving object, FIG. 7 is a character data extraction procedure for extracting character data corresponding to characters from map data to be processed, and a one-point perspective projection view in which the map data not including the character data is viewed from one point in the air on the terrain corresponding to the map data. A map data conversion procedure for converting the data into a bird's-eye view and outputting bird's-eye map data; and converting the extracted character data into a predetermined gain value g at a depression angle θ with respect to the point in the air at a point corresponding to the character data. (However, the angle (g) obtained by multiplying by 1 <g)
θ), a character data conversion procedure for converting into a pseudo bird's-eye view perspectiveed at a depression angle θ ′ and outputting pseudo bird's-eye character data, and corresponding to the output pseudo bird's-eye character data and the output pseudo bird's-eye character data To combine the outputted bird's-eye view map data to generate combined bird's-eye view data, and a display control procedure for displaying the combined bird's-eye view corresponding to the generated combined bird's-eye view data on the display means. A computer-readable recording medium recording a map display control program. 9. A map display control device comprising a computer for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting the movement of the moving object, And a point having a depression angle θ of not less than a predetermined lower limit value θ _L (where 0 ° <θ _L <90 °) with respect to one point in the air in the map data including the character data corresponding to the characters in the map. The corresponding portion is converted into a bird's-eye view, which is a one-point perspective projection view of the terrain corresponding to the map data from one point in the air, and outputs bird's-eye view data, and the map data is based on the one point in the air. map data conversion to convert the portion corresponding to the point having the depression angle theta is less than the lower limit theta _L pseudo bird's eye view obtained by transmission at depression angle theta 'equal to said lower limit theta _L, and outputs the pseudo bird's-eye view data Order and, the outputted bird's-eye view data and the pseudo bird's eye view A computer-readable recording medium map display control program for executing a display control procedure to be displayed on said display means the bird's-eye view corresponding to the data. 10. A map display control device comprising a computer for controlling a display of the map by the display means in a navigation device for displaying a map by a display means and assisting the movement of the moving object. The map data including the character data corresponding to the characters in the map is converted to a predetermined gain value g (where 1 <
g) is converted into a perspective bird's-eye view perspectiveed at a depression angle θ ′ equal to the angle (gθ) obtained by multiplying the bird's-eye view data corresponding to the outputted pseudo bird's-eye view data. A computer-readable recording medium recording a map display control program for executing a display control procedure to be displayed on the display means.