JPH03174182A - Navigation device for moving body - Google Patents

Abstract

PURPOSE:To shorten the time after an operation is started before a map is displayed on a screen by dividing the map to plural regions, temporarily storing the map information, etc., read out of a map memory means, setting the prescribed geographical coordinates, etc. at the approximate center of a display device and plotting the same. CONSTITUTION:The map memory means 25a which divides the map to the plural regions, stores the same as the map information, breaks down the diagrams of the maps to plural pieces of point data and line kind data and stores the data is provided. The map block plotted at the center of the screen of a display device 26 and the map information of the adjacent map block are read out and are stored in a temporary storage memory 8 when the operation to select the desired map is carried out. The corresponding diagram is restored and is displayed together with the map block on the screen. The prescribed coordinates on the geography of the map displayed at this time are so controlled as to be set at the approximate center of the screen of the display device 26. The time after the operation is started before the map is displayed on the display device 26 is shortened in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a navigation device installed in a moving body such as an automobile, and in particular, displays a map, the current position of the automobile, a traveling trajectory, etc. on a display such as a cathode ray tube. The present invention relates to a navigation device for a mobile body that displays driving information to a driver.

[Conventional technology]

Navigation devices installed in moving objects such as automobiles are
Generally, a national map, a regional map divided into multiple parts, etc. is stored as map information in a map storage means, and the above map information is read out in response to an operator's request and displayed on a display such as a cathode ray tube. It now provides a map for driving.

In addition, by calculating the current position of the vehicle based on detection signals from a distance sensor that detects the distance traveled by the vehicle and a direction sensor that detects the heading direction, the current position of the vehicle is displayed on the map displayed on the display. A triangular mark indicating the position and the driving trajectory are displayed as a plurality of consecutive points, so that the vehicle's position on the map on the screen can be visually confirmed (for example, Japanese Patent Application Laid-Open No. 58-53711, Japanese Patent Publication No. 59-1983). 39
800, JP-A-60-165511)
.

In the conventional device described above, when a function key is operated while the vehicle is running, a map showing the current position is displayed on the screen as the vehicle moves, and information necessary for driving is displayed on the screen. provided.

[Problem to be solved by the invention]

However, the above-mentioned conventional device has the problem that when the vehicle is running, it takes a long time from when a key is operated until a desired map is displayed on the screen, and there is a waiting time before the vehicle starts moving.

In other words, if you want to set the vehicle's departure point to predetermined geographical coordinates, such as your home, you first select a detailed map from the wide-area map by key operation and display it on the screen, and then select the desired district map from this detailed map. After that, you need to set the geographical coordinate center to the center of the screen. At this time, the desired map is selected while looking at the map displayed on the screen, but the detailed district map is stored divided into multiple map blocks corresponding to the screen, and is stored in the map storage means. When the map blocks are read out from the map and displayed on the screen of the display device, each map block is drawn in sequence, so it takes several tens of seconds to complete the drawing of all the map blocks.

Furthermore, if the engine is stopped and the key switch is turned off after the vehicle has been driven, the map showing the current location that was displayed on the screen immediately before the vehicle stopped will be erased. When starting to drive again, displaying a map showing the current location requires a long wait time until all map blocks have been drawn as described above, which is a source of frustration for the driver. .

This invention was made in view of the above problems, and speeds up the time it takes to read map data etc. from a map storage means and draw it on the screen of a display device, and sets the center of geographical coordinates at the center of the screen. In addition to significantly reducing waiting time,
It is an object of the present invention to provide a navigation device for a mobile object that is easy to handle by simplifying map selection and current position setting operations.

[Means to solve the problem]

The mobile navigation device according to the present invention divides a map into a plurality of regions and stores them as map information.
A map storage means that stores the line diagram of this map by dividing it into a plurality of point data and line type data indicating the type of cotton connecting each point, and a map block that displays the map divided into the plurality of regions on the screen. means for setting a predetermined geographical coordinate approximately at the center of the screen of the display based on a command signal; a map block containing the predetermined geographical coordinate; and a map block adjacent to the map block; Means for reading map information of a map block from the map storage means and storing it in a temporary storage memory, restoring a line diagram based on point data and line type data of the map block including the predetermined coordinates, and displaying it on the display device. a first drawing means; a second drawing means for restoring a line diagram based on some point data and line type data of the adjacent map block after the operation of the first drawing means is completed, and causing the line diagram to be drawn on the display; It is something that

[Effect]

In this invention, when an operation for selecting a desired map is performed, map information of a map block drawn in the center of the screen of the display device and map blocks adjacent to this map block are first read out from the map storage means. Ru. Along with this,
A line diagram corresponding to this map is restored and displayed on the screen together with the map blocks, and at this time, predetermined geographical coordinates of the map displayed on the screen are set approximately at the center of the screen of the display device. Therefore, the time from the start of the operation until the map is displayed on the display device is significantly shortened.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is an overall configuration diagram of a mobile navigation device, FIG. 2 is a front view of a display, and FIG. 3 is a schematic configuration diagram for explaining the present invention in detail.

In the figure, (1) is a control unit, and various I10 circuits (
2), (3), (4) and input/output boats (5), (6
), and the CPU (7), CRT/C (9), etc. are operated by receiving stabilized power from the on-board battery via a constant voltage circuit to control various devices.

(2) is the first I10 interface circuit, which includes a navigation (11) that guides the driving of the vehicle, a traffic information (12) that receives road conditions, and a wireless telephone (13) for the car.
), indoor air conditioner (14), television (15), radio (16), tape (17), and CO (18), etc. It is possible to select it via .

These function switches (SWI) to (SW8) are the front panel (26b) of the CRT (26) shown in FIG.
), and the drive signal is suppressed by the suppression operation.
p u (7) to operate each device.

In addition, the first I10 interface circuit (2) includes:
A GP that receives radio waves from artificial satellites via an antenna and can confirm and determine the current location and moving speed of a vehicle.
The S device (19) and a flux-kent type geomagnetic detector fixed to the vehicle separate and detect the geomagnetic field into a component in the vehicle's traveling direction and a component perpendicular to the component, and a signal corresponding to this component is sent to detect the component in the vehicle's traveling direction. A direction sensor that outputs the direction θ (
20) are connected.

(3) is the second I10 interface circuit, to which is connected a distance sensor (21) that outputs a pulse signal proportional to the number of wheel rotations using a vehicle speed sensor that detects wheel rotation using an electromagnetic pickup, reed switch, etc. has been done. Note that the current position data of the vehicle is obtained by the azimuth sensor (20) and the distance sensor (21), and
This constitutes a current position detecting means that can obtain travel trajectory data.

(4) is the third I10 interface circuit, which is used for video and video equipment such as a TV tuner (22), radio tuner (23), tape deck (24), and CD deck (25).
Audio equipment is connected. This CD deck (25) is equipped with a CD-ROM (25a) which is a map storage means, and when the above-mentioned navigation (11) is selected, various map information and line diagram data, etc., which will be described later, are read out and stored in the CD-ROM (25a).
It can be displayed on RT (26). In addition, the above CD
・For ROM (25a), NIKKEl, ELεC
TR0NICS, November 26, 1987 issue (NO4
The memory for storing map information described in 34) is employed, and map information such as national maps, local maps, regional maps, and even district maps is stored as vector data.

Further, in this example, there are three types of maps, wide area, standard, and detailed, each having a different scale, and this map information is stored so as to include a common area. The above district map is divided into four areas corresponding to the four quadrants of the screen (26a) of the CRT (26), and the four map blocks are considered as partial maps, and one map block that is a part of this partial map is The data is used as map information on the above CD/R so that 4 times the background of the screen (26a) of the CRT (26)
They are sequentially stored in the OM (25a). In addition, line diagrams connecting points on this district map, such as line diagrams showing roads, rivers, bridges, etc., are decomposed into line diagram data and stored, as well as character data such as letters and symbols, and service symbols. Service data of hotels, golf courses, etc. is also stored. For specific items such as roads, rivers, and bridges, color palettes are stored in a plurality of color codes in order to display them in various colors. Moreover, in order to be able to display the above-mentioned items in other colors in addition to this color code, it has a plurality of memory tables in which a large number of color palettes are stored in color codes. Further, dot data for applying a shadow to the screen (26a) and dot data for applying a shadow to an area where an icon, which is a touch pattern, is displayed on the screen (26a) are stored, respectively.

(7) is the CPU, and the function switch (
The operation of the video/audio equipment is controlled based on the selection operations of SWI) to (SW8), and the operation of the CD-ROM (2) is controlled.
A control signal for reading map information etc. from the CRT (5a) and displaying it on the screen (26a) of the CRT (26) is sent to the CRT (26).
Give to C(9).

In addition, the pulse signal from the distance sensor (21) via the IRT (interrupt circuit) (7a), the GPS device (19)
GPS signal from and direction sensor (20) from X, Y
The system receives li digital signals, executes arithmetic processing, determines the driving trajectory and current position as driving route information, and outputs a display signal.

(8) is a temporary storage RAM which is a time storage means, and as shown in the schematic diagram of FIG.
In the process of performing arithmetic processing, the above CD-ROM (25a)
Power is constantly backed up from the on-vehicle battery so that data read from the vehicle can be temporarily stored and retained. When map information is read out, line map data is also read out, and when a desired map is selected, the data is extracted so that various line maps are superimposed on the selected map. Note that this RAM (8) contains the above-mentioned CD-ROM (25
The coordinates (XO, YO) of the current position stored in the first memory table in a) are stored so as to be at the center of the screen (26a), and when this current position data is read out, the coordinates (XO, YO) of the current position stored in the first memory table of
The current position mark (M) is displayed at the center of 6a). Also, the screen (2) of the above CRT (26)
6a) is equipped with a memory table for storing position data, and in this example, the above-mentioned CD
- It has a plurality of endless memory tables corresponding to map information of maps of different scales stored in the ROM (25a).

(9) is a CRT-C (CRT controller) which is a display control means, which receives a command for outputting a display signal from the CPU (7) and develops travel route information in a display RAM (10). At the same time, the developed map data, character data, driving route information, etc. are CR
It outputs a video signal and a synchronization signal to be displayed on T (26). In addition, the above CPU (7)
is the map information corresponding to one designated scale among the partial map information, wide area, standard and detailed map information which are the above four map blocks stored in the CD-ROM (25a), and the map information comparable to this map information. The above R
The travel trajectory is read out from the memory table of AM (8) and displayed superimposed on the line diagram on the ground support.

(lO) is a display RAM that stores additional information such as map number and scale type, as well as pattern data for displaying the operation keys that drive the various devices mentioned above as touch switches on the screen (26a). has been done. This pattern data includes the current position mark (M) displayed as a triangle on the screen (26a) of the CRT (26) (see Figure 3), and the current position mark (M) that is displayed in the form of a triangle on the screen (26a) of the CRT (26) (see Figure 3); The trajectory display pattern which is the first mode and the trajectory non-display pattern which is the second mode for erasing the displayed trajectory from the screen (26a) are controlled by a switching means that provides a switching signal to the CPU (7), that is, a touch. It is remembered as a switch.

Although not shown, there is also a scroll key pattern constituting a map moving means for arbitrarily moving the map displayed on the screen (26a), and the current position mark (M) displayed on the screen (26a). A correction position mark that is a correction position mark display means for correcting a position, a return pattern that is a map movement return means that returns a moved map to its original position, and a correction position mark that is used when the current position mark (M) is moved. A correction pattern, etc., which is a current position mark correction means for moving the current position mark to the position of the position mark, is stored. moreover,
Although not shown, enlargement and reduction patterns for specifying the map scale are also stored.

(26) is a CRT which is a display device, and the above-mentioned CRT
A map of a specific area, a driving route, a current position, etc. are displayed in color using the video signal and synchronization signal from -C (9). In addition, various operation keys of the touch switch section, which will be described later, are displayed in a predetermined touch area, and it is also possible to turn on the TV tuner (22) and display TV images by pressing the function switch (SW5). There is.

(27) and (29) are connected to the CPU via the output port (6).
(7) is a light emitting unit connected to the CPU (7), and (28) and (30) are light receiving units connected to the CPU (7) via the input board (5), which are arranged on the surface of the CRT (26). It constitutes the touch panel part of the touch switch. Although not shown, this touch panel section is divided into a large number of touch areas in the row direction and column direction, and when a specific touch area among these touch areas is touched, the touch area in the row direction and the column direction is Infrared light passing through the intersection with the direction is cut off, and drive signals giving various instructions are output. Specifically, the screen (
When you touch 26a), the above operation patterns are displayed on the inner periphery of the screen (26a), and when you touch any of these patterns, you can start or stop the operation of each device, and set the time, numerical value, etc. It is something that can be done.

Next, the operation of the mobile navigation device configured as described above will be explained with reference to the flowcharts shown in FIGS. 4, 8 to 12.

First, when a key switch is turned on when starting to drive a car, the electric system of each part is activated by receiving power from the car's on-board battery. And the CPU (7) of the control unit (1)
When the power is turned on, it is operated by a stabilized power supply, initialization is performed in step Sll of the flowchart shown in FIG. 4, and the arithmetic processing shown in the main routine of the same figure is repeated at a cycle of about several 10 m5ec. Next, function key processing is performed in step S12, followed by touch switch input processing in step S13. At this time, in step S14, for example, when the operator presses the function switches (SW6) and (SW4) of the radio (16), air conditioner (14), etc., the process proceeds to step S15, and the screen of the CRT (26) ( In 26a), a radio mode pattern as shown in FIG. 5 or an air conditioner mode pattern as shown in FIG. 6 is displayed. Then, by touching the area of the switch pattern provided on the display screen of each mode, the selected device can be operated according to the desired settings.

Note that even during such an operation, the process proceeds to step S16, and the CP 11 (7) executes current position calculation processing and the like.

First, as shown in the flowchart of FIG. 8, in step 521, the distance sensor (21) detects the distance traveled by the vehicle. Next, in step S22, in response to a pulse signal from the distance sensor (21), an interrupt calculation of the current position is performed at predetermined time intervals. Then, in step S23, the current position data and travel trajectory data obtained by this calculation are stored in a temporary storage RAM (8
) are stored sequentially. As a result, when the vehicle starts traveling, travel route information such as the travel distance to the current location and the travel trajectory can be obtained.

First, when the car is driven, a pulse signal is output from the distance sensor (21) as shown in the flowchart of FIG.
) is given to Then, the number of pulses N is added by this CP 11 (7), and the distance traveled up to the present time is determined (step 531).

Next, as the automobile travels, an interrupt processing routine shown in the flowchart of FIG. 10 is started.

First, in step S41, for a certain period of time, for example, 1
Read the number of pulses N from the vehicle speed sensor at the column intervals.

Next, in step S42, the number of pulses N at this time,
By multiplying by the unit traveling distance d, for example, 39.25 cm, the traveling distance for each fixed period of time is determined.

Then, in step S43, the direction θ from the direction sensor (20) is read.

Subsequently, in step S44, this direction θ and the travel distance θ are determined.
The position of the vehicle on the two-dimensional coordinates is determined from the following equation.

After this, in step S45, the coordinates calculated above (△X,
Δy) and the coordinates of the starting point (xo + yo), the vehicle's current position 1ffi(x, y) is determined by the following equation.

As a result, the distance traveled to the current position, which changes every moment, can be obtained, and the latitude and longitude are determined at regular intervals, so that the current position <x, y> can be known. Note that this data is sent to temporary storage RAM (8) and stored in sequence, but in this RAM (8), while data at the current position (x, y) is written, old data is written one after another. It is a so-called endless method of being erased. Furthermore, even if the vehicle is stopped and the key switch is turned off, the current position (x, y) and distance traveled data can be retained.

Note that in step S46, the count of the number of pulses N is cleared. Then, proceeding to step S47,
After receiving the GPS signal from the above GPS device (one),
Arithmetic processing for performing S processing is executed. As a result, the absolute values of the latitude and longitude are determined every fixed period of time, for example, every second, so that the traveling route information can be corrected.

By the way, when starting the car, the user operates the navigation system (11) to set the starting point at predetermined geographical coordinates, for example, one's home on a detailed district map.

Now, when the function switch (SWI) of the navigation (11) is pressed, a menu is displayed on the screen (26a) of the JT (26) as shown in Figure 7, allowing you to select the map and the current location. The setting pattern, which is the touch area, is displayed.

As a result, the map display mode shown in the flowchart of FIG. 11 is started, and in step S51 the screen (26
When the menu is displayed in a), if the setting pattern for map selection is touched, it is determined in step S52 whether to select the map or the current location. Note that when the pattern of the current location is touched, the process advances to step S53, but at this time, map selection is set, so the map information of the Japanese map is retrieved from the CD-ROM (25a) that stores map information. As shown in FIG. 13(a), the CRT
A map of Japan is displayed on the screen (26a) of (26) (step 554). Next, if you press the pattern of a part of the region, for example, Kinki, on this Japanese map, step S
At 55, a local map selection process is performed and the screen (26a) is switched. Thereby, the process advances to step S56, and a map of the Kinki region is displayed as shown in FIG. 13(b). Next, in step S57, select a part of this local map, for example, Hyogo Prefecture, and press that pattern to proceed to step 35B, and as shown in FIG. 13(c), a regional map with Hyogo Prefecture in the center is displayed. is displayed on the screen (26a). Furthermore, select the desired district from this regional map and click the screen (26a).
When the area is touched, the process advances to step S59, and a district map selection process is performed. At this time, in step S60, which is a coordinate setting means, from CPLI (7) to CR
A command signal is output to the T-C (9), and the coordinates of your home, which is a predetermined geographical location, are displayed on the CRT (26) screen (
26a).

As a result, in step S61, which is a data storage means, the map information of the map block including the above-mentioned coordinates and the map information of the map block adjacent to this map block are read out from the CD-ROM (18), and the map information of the map block adjacent to this map block is read out from the CD-ROM (18). I? A
Stored in M(8). Along with this, the process advances to step S62, where the above map information is sent to the CRT (26), and the screen (26a) displays a total of four map blocks, including a map block centered on the home coordinates and a map block adjacent to this. map is drawn.

Step S63 is a first drawing means, and the CD-ROM
The point data and line type data of the map block including the above coordinates are read from (25a), and -1? for temporal storage? A
Store in M (8). Then, this data is displayed on the CRT
Since it is immediately sent to (26), it is restored on the screen (26a) as a diagram showing roads, rivers, bridges, etc.

Step S64 is a second drawing means, and the above-mentioned CD/RO
Read some point data and line type data of the adjacent map block from M (25a), -RA for time storage.
Store in M (8). Then, this data is displayed on the CRT
Since it is immediately sent to (26), the screen (26a) shows
A line diagram that is continuous with the line diagram of the central map block is restored and drawn on the district map, as shown in FIG. 13(d), so that the desired district map is displayed.

This kind of drawing is done when map information and various data are stored on a CD.
-Read from ROM (18), -RAM for time storage
(8) and at the same time transferred to the CRT (26), the map will be displayed on the screen (26a) within a few seconds after the map selection setting operation is performed. This allows CRT
The home and vehicle position, which are the geographical centers of the map drawn at the center of the screen (26a) in (26), are set.

After this, when I start the car, the CD-RO? I(1
Map information is sequentially read out from B), and the map drawn on the screen (26a) of the CRT (26) is automatically switched depending on the direction of travel, so-called scrolling is performed, and driving information is provided to the driver. .

When the vehicle is stopped in this state, the key switch is turned off, and the navigation (11) is turned off, the current position is stored in the temporary storage RAM (8).

Next, the operation for selecting the current position when the vehicle starts traveling again will be explained. First, the key switch is turned on and the function switch (SWI) of the navigation (11) shown in FIG. 1 is pressed.

Next, in order to set the starting point as the current position prior to driving, press the setting pattern for the current position area displayed on the screen (26a) of the CRT (26), and the subroutine calculation processing shown in Fig. 12 will be executed. be done.

At this time, a command signal is output from the CRT (26), and the CRT-C (9) is operated at step S, which is the coordinate setting means.
At step 71, an instruction is given to set the coordinates of the own army, which is a predetermined geographical position, at the center of the screen (26a) of the CRT (26).

As a result, in step S72, which is a data storage means, a map program containing the coordinates of the vehicle's position is executed.

The next map information and the map information adjacent to this map block are read out and stored in the RAM (8) for -time storage. Then, in step S73, this map information is displayed on the CRT.
(2G), and a map consisting of a map block centered on the coordinates of the own army and adjacent map blocks is displayed on the screen (26a).

Further, in step S74, which is the first drawing means, the point data and line type data of the map block including the above coordinates are read out from the temporary storage RAM (8), and
(8). At this time, is this data CI? T
Since it is immediately sent to (26), the screen (26a) shows
Various line diagrams are restored.

Further, in step S75, which is the second drawing means, the C
Some point data and line type data of the adjacent map blocks are read from the D-ROM (1B) and stored in the RAM (8) for -time storage. Then, is this data CII? (26), so the screen (26) is sent immediately.
In 6a), a line diagram that is continuous with the line diagram of the central map block is restored and drawn on the district map. This kind of drawing is done within a few seconds after the current position setting operation is performed, so the current position of the vehicle will be aligned with the center of the map displayed on the screen (26a), and the vehicle will be able to depart from this current position. It becomes possible to start the car as a point.

As described above, in this embodiment, a district map, which is a detailed map, is divided into four map blocks and stored, and a line diagram corresponding to this map is divided and stored on a CD/ROM (
18), and when you select a map or set the current position at the start of navigation, this C
Map information and various data are read from the D-ROM (18) and stored in the RAM (8) for time storage.
The image is also drawn on the screen (26a) of the CRT (26). Therefore, after performing the setting operation, the screen (26
The time it takes for the map to be displayed in a) is a few seconds, eliminating the waiting time required for map blocks to be drawn sequentially in predetermined quadrants of the screen (26a) as in the past. The time required to display the map on the screen (26a) is significantly reduced. Also, the screen (26a)
When a map is drawn, the coordinates of the map indicating the current position are set at the center of the screen (26a), so once the drawing of the map block including the vehicle's position is completed, the vehicle's position can be recognized quickly. , you can immediately start driving.

Furthermore, when a map is drawn on the screen (26a) of the CRT (26), predetermined geographical coordinates (
xo + YO) can be set at the center of the screen (26a), so there is no need to re-determine your position every time you start moving again after the car stops running, which frees you from cumbersome handling operations. There are effects such as being

〔Effect of the invention〕

As described above, the present invention includes a map storage means that divides a map into a plurality of areas and stores them as map information, and also divides a line diagram corresponding to the map into line type data and stores the divided areas;
means for temporarily storing the map information and line type data, etc.; means for setting predetermined geographical coordinates approximately at the center of the screen of the display device; first and second means for drawing the map, etc. on the screen of the display device; It is equipped with a drawing means, etc., and when an operation is performed to display a map on the screen during navigation of a mobile object, the map information read out from the map storage means is temporarily stored and immediately drawn on the screen. The time from the start until the map is displayed on the screen is significantly shortened, which has the effect of eliminating the perceived waiting time.

[Brief explanation of the drawing]

1 to 13 show an embodiment of the present invention,
Fig. 1 is an overall configuration diagram, Fig. 2 is a front view of the display, Fig. 3 is a schematic configuration diagram for explaining the present invention in detail, and Fig. 4 shows the entire arithmetic processing of the main routine in the control section. 5 to 7 are explanatory diagrams of various menus displayed on the screen of the display unit, FIG. 8 is a flowchart showing the calculation processing of the navigation main routine, and FIG. 9 is a distance pulse from the distance sensor. 10 is a flowchart showing the interrupt calculation routine based on the distance pulse from the distance sensor and the signal from the direction sensor. FIG. 11 shows the detailed calculation process of the map ashes setting routine. flowchart,
FIG. 12 is a flowchart showing detailed calculation processing of the current position setting routine, and FIGS. 13(a) to 13(d) show display examples of maps drawn on the display. In the mouth, (1) is the control unit, (7) is the CPU, (8)
- Time storage means (RAM), (9) is CRT・C,00
) is display RAM, (11) is navigation, (2
0) is a direction sensor, (21) is a distance sensor, (25a)
(26) is a map storage means (CD-ROM) and a display (CRT). In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) Divide a map into multiple areas and store them as map information, and store the line diagram of this map by breaking it down into multiple point data and line type data indicating the type of line connecting each point. a display device for displaying the map divided into a plurality of regions as map blocks on a screen; and a device for setting predetermined geographical coordinates approximately at the center of the screen of the display device based on a command signal. , means for reading map information of a map block including the predetermined geographical coordinates and map blocks adjacent to the map block from the map storage means and storing the map information in a temporary storage memory; point data of the map block including the predetermined coordinates; and a first drawing means for restoring a line diagram based on the line type data and drawing it on the display, and after the operation of the first drawing means is finished, based on the point data and line type data of a part of the adjacent map block. A navigation device for a mobile body, comprising a second drawing means for restoring a line diagram and drawing it on the display.