Time display method and apparatus

• US 6,366,834 B1
• Filed: 06/08/2000
• Issued: 04/02/2002
• Est. Priority Date: 06/08/2000
• Status: Active Grant

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Mitchell, John, Hayes, David
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US09/589,835
• Time in Patent Office: 663 Days
• Field of Search: 701/1, 701/200, 701/201, 701/211, 701/25, 701/26, 340/988, 340/990, 340/995, 368/10, 368/14, 368/21, 368/22, 368/23
• US Class Current: 701/1
• CPC Class Codes: G04G 9/0076 in which the time in another time-zone or in another city can be displayed at will

Abstract

A difference in time from a standard time for each state, or where a state belongs to a plurality of time zones, a difference in time for each time zone and boundary information for specifying a state portion belonging to each time zone, are stored. In operation, a state in which a vehicle is present is detected, a check is made to determine whether the state in which the vehicle is present belongs to only one time zone by referring to the stored information, and if the state belongs to only one time zone, a time display is provided on the basis of the difference in time corresponding to that time zone. However, if the state in which the vehicle is present belongs to two time zones, a state portion where the vehicle is present is obtained on the basis of the boundary information and the vehicle'"'"'s present position, and a time display is provided on the basis of the difference in time corresponding to the time zone associated with said state portion.

Claims

1. A time display method for displaying the present time in a vehicle in consideration of a delay time from a standard time, the method comprising:

storing a delay time from the standard time for each of a plurality of geographic regions, and, where a region includes a plurality of time zones, storing respective delay times and boundary information for specifying a region portion associated with each time zone;

monitoring the present position of the vehicle and detecting a region in which the vehicle is present;

where the region in which the vehicle is present is associated with only one time zone, as determined by referring to said stored information, providing a time display on the basis of the delay time corresponding to the time zone associated with the region in which the vehicle is present; and

where the region in which the vehicle is present is associated with a plurality of time zones, determining the region portion in which the vehicle is present on the basis of said boundary information and said vehicle present position, and providing a time display on the basis of the delay time corresponding to the time zone associated with the region portion in which the vehicle is present.

2. The time display method according to claim 1, wherein said region portion is approximated by a rectangle, and the boundary of the region portion is defined by longitudes and latitudes of two diagonal points of said rectangle.

3. The time display method according to claim 1, provided with a data base storing, for every region, names of cities belonging to said region, and roads present in the cities, comprising;

determining the name of the road on which the vehicle is running at present; and

determining the region in which the vehicle is present by referring to said data base.

4. The time display method according to claim 3, wherein a navigation function for guiding the vehicle to a destination is provided on the vehicle, so that the name of the road on which the vehicle is running at present is obtained using map information for navigation.

5. The time display method according to claim 1, further comprising:

storing information identifying whether or not daylight saving is enforced for every region;

determining whether or not the region in which the vehicle is present is enforcing daylight saving by referring to said stored information;

if said region is not enforcing daylight saving, providing a time display on the basis of the delay time corresponding to the time zone of said region; and

if said region is enforcing daylight saving, judging whether the time display is to be made on the basis of either summer time or winter time and providing a time display on the basis of the delay time from the standard time in summer time or winter time of said region.

6. The time display method according to claim 1, wherein said region is a state.

7. A time display apparatus for displaying the present time in a vehicle in consideration of a delay time from a standard time, the apparatus comprising:

a memory for storing a delay time from the standard time or a time zone name for each of a plurality of geographic regions in which the vehicle may travel, and, where a region includes a plurality of time zones, storing respective delay times or respective time zone names and boundary information for specifying a region portion associated with each time zone;

means for monitoring the present position of the vehicle;

means for detecting a region in which a vehicle is present;

means for calculating a present time, which, if the region in which the vehicle is present is associated with only one time zone, calculates the present time on the basis of the delay time corresponding to said one time zone, and if the region in which the vehicle is present is associated with a plurality of time zones, calculates the present time on the basis of the delay time corresponding to the time zone associated with the region portion in which the vehicle is present; and

a display portion for displaying the calculated present time.

8. The time display apparatus according to claim 7, wherein said region portion is approximated by a rectangle, and said boundary information for the region portion comprises longitudes and latitudes of two diagonal points of said rectangle.

9. The time display apparatus according to claim 7, wherein said means for calculating a present time determines a region portion in which the vehicle is present on the basis of the boundary information and the present vehicle position, and calculates the present time on the basis of the delay time corresponding to said region portion.

10. The time display apparatus according to claim 7, wherein said means for detecting a region in which the vehicle is present comprises:

a data base for storing, for every region, names of cities belonging to said region, and roads present in said cities; and

means for obtaining the name of the road on which the vehicle currently is running, thereby

determining the region in which the vehicle is present from the name of the current road and said data base.

11. The time display apparatus according to claim 10, wherein said means for obtaining the current road determines the name of the current road using map information for navigation guidance and the present vehicle position information.

12. The time display apparatus according to claim 7, wherein said memory stores information on whether or not daylight saving is enforced for every region, and

said means for calculating a present time, by referring to said stored information, if said region does not enforce daylight saving, calculates the present time on the basis of the delay time corresponding to the time zone of said region, and if said region enforces daylight saving, calculates the present time on the basis of the delay time from the standard time in either summer time or winter time.

13. The time display apparatus according to claim 12, comprising means for setting manually a time zone for a time display, and setting manually whether or not time is to be displayed on the basis of daylight saving,

wherein said means for calculating a present time calculates the present time on the basis of the information entered manually.