Data processing: vehicles – navigation – and relative location – Navigation – Employing position determining equipment
Reexamination Certificate
2001-04-02
2004-12-14
Louis-Jacques, Jacques H. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Navigation
Employing position determining equipment
C701S025000, C342S357490, C340S995180, C711S165000
Reexamination Certificate
active
06832154
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a navigation system that navigates using map data recorded in a recording medium, and in particular, to a navigation system equipped with a hard disk that stores the map data.
2. Description of the Related Art
There has been widely known a navigation system, which has a DVD-ROM drive unit or a CD-ROM drive unit, reads out the map data from a DVD-ROM or a CD-ROM as a recording medium to record map data therein to perform tasks of navigation. Differently from those recording mediums, a configuration can be considered, in which a hard disk, which functions as a nonvolatile storing means with a large memory capacity, is mounted in a navigation system. Because the hard disk has a higher access speed compared to mediums such as a DVD-ROM, the hard disk has a great advantage in that objects to be displayed based on map data can be depicted on a monitor screen at a high speed. If map data are transferred from, for example, a DVD-ROM drive to a hard disk in order to navigate, this is advantageous in that the DVD-ROM drive can be made use of other applications, such as music reproduction or image reproduction, even during navigation.
In general, a hard disk uses a filing system in which files corresponding to data to be stored are basically assigned to a continuous empty area and arranged therein. However, when the remaining empty areas of the hard disk are reduced due to the fact that a large number of files have been written, a file that should be stored subsequently is written in the remaining empty areas in such a condition that data are divided into small discontinuous fragments, not written in a single continuous area. When the files of which data are stored in divided areas are read out, an access speed to those files is inevitably lowered.
As a preventive measure against such lowering of the access speed, a defragmenting process has been usually executed in a hard disk. This defragmenting process is to cease such a discontinuously divided condition of a file by transferring a plurality of data fragments of each stored file to a continuously arranged area, thus avoiding such a divided condition. According to user's needs, a software program for the defragmenting process is activated. The defragmenting process permits an access speed to a hard disk to be prevented effectively from being lowered.
However, when executing the defragmenting process in the hard disk mounted in a navigation system, there is a fear that there may occur various types of interference with the performance of the defragmenting process, like cases that an engine stops in the course of execution of the defragmenting process, or reading out map data from the hard disk, becomes necessary, because the navigation is started. It is difficult for users to predict by themselves such occasions of interference before or after starting the defragmenting process, thus being much burden on users. The defragmenting process is no longer done effectively in the hard disk, thus it takes much time to read files of map data. There is a problem that a merit of a hard disk, which is inherently high is access speed, cannot sufficiently be utilized for navigation which should be performed at a higher speed.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the foregoing problem. An object of the present invention is to provide a navigation system, into which a hard disk is mounted, that is capable of executing a defragmenting process in the hard disk according to its necessity, thereby providing a high-speed access time to realize speedy and agreeable navigation.
The above object of the present invention can be achieved by a navigation system performing navigation based on a detected current position and map data in accordance with the present invention. The navigation system is provided with: a storage device such as a hard disk, which is nonvolatile, from and into which files of map data are able to be read and written; a navigation control device for controlling a navigation operation using the map data; and a defragmenting processing device for performing a defragmenting processing with the storage device at a predetermined time.
According to the navigation system of the present invention, the storage device is nonvolatile. Files of map data are able to be read and written from and into the storage device. The navigation control device controls a navigation operation using the map data. Then, the defragmenting processing device performs a defragmenting processing with the storage device at a predetermined time.
Therefore, even when the map data are frequently read and written responsively to the executed navigation, the defragmenting processing enables data arrangement in the storage device to be maintained in a proper state, thus preventing an access speed to the storage device from being lowered in a secure manner.
In one aspect of the navigation system of the present invention, the defragmenting processing device continuously arranges a plurality of data fragments being arranged in a divided form and belonging to the same file.
According to this aspect, when repeatedly writing data into the storage device, data in the storage device are relocated so as to become continuous. As a result, an access speed to the storing means is securely prevented from being lowered.
In another aspect of the navigation system of the present invention, the storage device is a hard disk mounted in a hard disk apparatus.
According to this aspect, the storage device is realized as a hard disk, which is high in memory capacity, versatility, and access speed. In addition, the defragmenting processing, which is effective in repeatedly reading and writing map data, can be executed to maintain its high access speed.
In another aspect of the navigation system of the present invention, the hard disk apparatus has: a head reading and writing information from and into the hard disk; and a providing device for providing a position to which the head is made to retract from a potion on the hard disk. Further, the defragmenting processing device continuously arranges specific data in the vicinity of the retracted position when the defragmenting processing is performed.
According to this aspect, specific data are continuously arranged in the vicinity of a retracted position of the head in executing the defragmenting processing. This configuration permits the defragmenting processing to be done with an access performance of the hard disk considered.
In another aspect of the navigation system of the present invention, the navigation system further includes an operation device with which executing the defragmenting processing in the storage device is able to be ordered. Then, the defragmenting processing device performs the defragmenting processing in response to the instruction of execution from the operation device.
According to this aspect, in cases the defragmenting processing is ordered by the operation device, the defragmenting processing of the storage device is activated. Hence, it is possible to continuously arrange data in the storage device by reflecting a user's will into timing of execution of the defragmenting processing. This is able to maintain a high access speed to the storage device for map data and others, which will lead to an agreeable navigation.
In another aspect of the navigation system of the present invention, the defragmenting processing device interrupts the defragmenting processing if a given condition is fulfilled during executing the defragmenting processing.
According to this aspect, the defragmenting processing device makes it possible to execute the defragmenting processing, while still judging various conditions, such as states of a vehicle and used states of the storage device, so as to interrupt the defragmenting processing if the conditions are met. If something unfavorable happens during the defragmenting processing, accidents such as data damage of the storage device can be prevented.
In another as
Nagaki Kouichi
Watanabe Tomoo
Louis-Jacques Jacques H.
Pioneer Corporation
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