The present invention relates to timepieces which are settable accurately and adapted for daylight saving time, surveillance or monitoring camera devices and a time setting method for the timepiece.
Daylight saving time is a system wherein timepieces are advanced by a predetermined period of time from the standard time during a specified period of from spring to fall. Daylight saving time is presently adopted by at least seventy countries. In the U.S., for example, the period of daylight saving time starts at 2 a.m. on the first Sunday of April and ends at 2 a.m. on the last Sunday of October, and during this period, timepieces are advanced by one hour. Stated more specifically with reference to
The timepiece adapted for daylight saving time automatically advances the standard time by a specified time correction value to indicate daylight saving time during the period of this system. Such a timepiece needs to have set therein information serving to provide a basis for judging whether the current time is within the period of daylight saving time. Generally provided as this information are conditions for a transition from the standard time to daylight saving time (hereinafter referred to as “DST transition conditions”) which are determined for each year and which comprise the starting time and ending time of the period of daylight saving time. In the case of the U.S. in 2001 AD shown in
In the case of such a timepiece, the user must seta time of day after turning on the power source. Further in the case where the time indicated differs from the correct time, the user must input the correct time to the timepiece to correct the time setting. Accordingly when the timepiece is to be set or corrected, it is likely that a time that can not exist under the system of daylight saving time will be input. Such a situation is very likely to occur in the case where the timepiece is set immediately after the start of the period of daylight saving time with reference to the indication of a timepiece which is not adapted for daylight saving time or which has not been changed over to this system. After the timepiece has been set, the timepiece counts time based on the time setting. Accordingly, if set erroneously, the timepiece will indicate incorrect times.
For example, reference will be made to the case of the U.S. shown in
Timepieces are used not only for indicating times but are used also as incorporated in a main apparatus to supply required time data to the main apparatus. For example, surveillance or monitoring camera devices for capturing images at intervals of a predetermined time period and recording the image data obtained are provided with a timepiece for giving time data to the image data. Such camera devices are intended for surveillance or monitoring for continually recording image data at intervals of a predetermined period of time, the time data for affording information as to the image capturing time must be accurate at all times. Setting the timepiece erroneously must be avoided especially in the case of the timepiece incorporated in the monitoring camera device.
The present invention provides a timepiece which is adapted for daylight saving time so that even if a time erroneous under the system of daylight saving time is set for the timepiece, the input time is automatically corrected for correct time setting, a time setting method for the timepiece, and a monitoring camera device comprising the timepiece.
The present invention provides a timepiece comprising a standard time clock for counting standard time and means for calculating daylight saving time by adding a predetermined time correction value to the standard time when judging that the standard time is within the period of daylight saving time, the timepiece being characterized in that when a time input for setting the timepiece is after a daylight saving time starting time as expressed in the standard time and before a daylight saving time starting time as expressed in daylight saving time, the input time is corrected by adding the time correction value thereto to set the corrected time as daylight saving time.
According to the invention, the timepiece is adapted to judge whether the time input for time setting is a time that is attributable to a changeover to daylight saving time and can not exist under the system of daylight saving time. Even when the time that can not exist under this system is input, the timepiece corrects the input time by adding a time correction value thereto, and handles the corrected time as daylight saving time. Thus, the timepiece is set, with the corrected time, that is a daylight saving time, entered as the time to be set. Accordingly correct time is set for the timepiece even if a time that can not exist under the system of daylight saving time is input.
The present invention further provides a timepiece which, when a time input for setting the timepiece is after a daylight saving time starting time as expressed in the standard time and before a daylight saving time starting time as expressed in daylight saving time, the timepiece sets the input time as it is for the standard time clock. Thus, correct time is set for the timepiece even if a time that can not be present under the System of daylight saving time is input.
The present invention further provides a monitoring camera device which comprises the above timepiece and wherein time data output from the timepiece when an image is captured is added as image capturing time data to image data obtained by capturing the image.
The monitoring camera device has the timepiece incorporated therein, whereby accurate time data can be added to the image data recorded successively and continually at intervals of a predetermined period of time even when a time that can not exist under the system of daylight saving time is input.
The present invention provides a time setting method for a timepiece comprising a standard time clock for counting standard time and means for calculating daylight saving time by adding a predetermined time correction value to the standard time when judging that the standard time is within the period of daylight saving time, the time setting method being characterized in that the method comprises the steps of: inputting to the timepiece the time to be set, judging whether the input time is after a daylight saving time starting time as expressed in the standard time and before a daylight saving time starting time as expressed in daylight saving time, correcting the input time by adding the time correction value thereto when the input time is after a daylight saving time starting time as expressed in the standard time and before a daylight saving time starting time as expressed in daylight saving time, and setting the corrected time as daylight saving time.
The invention provides another time setting method for a timepiece which method is characterized by setting an input time as it is for the standard time clock when the input time is after a daylight saving time starting time as expressed in the standard time and before a daylight saving time starting time as expressed in daylight saving time.
According to the method of the invention, the timepiece is adapted to judge whether the time input for time setting can not exist under the system of daylight saving time, and correct time is set for the timepiece even if the time input can not exist under the system of daylight saving time.
Embodiments of the present invention will be described below in detail with reference to the drawings. The system of daylight saving time will be described with reference to the case of the U.S. in 2001 shown in
The compressed image data stored in the memory buffer 21 has attached thereto, as subinformation, image capturing time data output from the CPU 11 when images are captured. The compressed image data is stored via the CPU 11 on a hard disk 7 which is a recording medium randomly accessible. The CPU 11 processes the compressed image data on the hard disk 7 for the expansion of the data. A video encoder 13 adds a synchronizing signal and color burst signal to the digital image signal resulting from expansion of the data. The image signal is thereafter converted to an analog image signal by a D/A converter 15. A monitor 17 displays images based on the analog image signal. The monitor 17 serves also as a display for indicating to the user various settings, especially settings of times of day or the DST transition conditions.
A system controller 23 controls the CPU 11 in response to the manipulation of manual buttons 25. When suitably manipulated, manual buttons 25 set the timepiece 31 in a time setting mode. In the time setting mode, particulars about a time setting are presented on the screen of the monitor 17 as shown in
When the timepiece 31 is set in a daylight saving time setting mode by manipulating manual buttons 25, particulars about a daylight saving time setting are presented on the screen of the monitor 17 as shown in
As previously described, data as to the year is set in the time setting mode. In the case shown in
Next, a description will be given of the operation of the timepiece 31 comprising the standard clock 19, CPU 11, etc., with attention directed mainly to the processing to be performed by the CPU 11.
First, the time calculating operation of the timepiece 31 will be described with reference to
When the answer to the inquiry of step S1 is affirmative, the CPU 11 adds a time correction value for use during the period of daylight saving time to the standard time to calculate daylight saving time, and outputs daylight saving time data indicating the daylight saving time (S3). The time correction value for use during the period of daylight saving time refers to the time difference value between the standard time and daylight saving time. In the illustrated case of
Next, the time setting operation of the timepiece 31 will be described with reference to
In the case where the input time is outside daylight saving time zone, the CPU 11 judges the input time to be standard time, and sets the time data indicating the input time as it is for the standard clock 19 (S13). The standard clock 19 having the time data stored therein starts to count standard time at the time indicated by the time data.
In the case where the input time is found to be within the daylight saving time zone (S12), the CPU 11 then inquires whether the input time is included within a time zone which does not exist under the system of daylight saving time (S14) The time zone not existing under the system of daylight saving time is after the daylight saving time starting time as expressed in the standard time and the subsequent time zone before (and not including) the daylight saving time starting time as expressed in daylight saving time (i.e., time corresponding to the starting time as expressed in the standard time plus the time correction value). In the illustrated case of
When the input time is within the daylight saving time zone and is found to be in the time zone not existing under the system of daylight saving time (S14), the input time is corrected by adding thereto the time correction value for use during the daylight saving time zone. The standard clock 19 is set based on the corrected time. With the corrected time interpreted as being daylight saving time, the CPU converts the corrected time to standard time as in step S15, and the standard time as converted from the corrected time is set for the standard clock 19 (S16). In the illustrated case of
When the input time is found to be within the daylight saving time zone (S22), the CPU 11 inquires whether the input time is included in a time zone not existing under the system of daylight saving time (S25). In the case where the input time is outside the time zone not existing under the system of daylight saving time, the CPU 11 judges the input time to be daylight saving time, converts the input time to standard time, and set a time indicating the converted standard time for the standard clock 19 (S26). Thus, time data indicating a time obtained by subtracting the time correction value from the input time is set for the standard clock 19. The standard clock 19 having the time data stored therein starts to count standard time at the time indicated by the time data, and the timepiece 31 outputs (in step S27) time data indicating a time obtained by adding the time correction value to the standard time according to the procedure shown in
In the case where the input time is within the time zone not existing under the system of daylight saving time (S25), the CPU 11 sets time data indicating the input time, as it is for the standard clock 19 (S28). The standard clock 19 having the input time data stored therein starts to count standard time at the time indicated by the time data, and the timepiece 31 outputs (in step S29) time data indicating a time obtained by adding time correction value to the standard time according to the procedure of
While embodiments of the present invention have been described above, the hard disk used as a recording medium for image data and the JPEG method used for compressing the image data for recording are intended to illustrate one embodiment of the invention, and the present invention are not limited to such means or method.
Number | Date | Country | Kind |
---|---|---|---|
2001-145900 | May 2001 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP02/04761 | 5/16/2002 | WO | 00 | 11/14/2003 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO02/093275 | 11/21/2002 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4956826 | Coyman et al. | Sep 1990 | A |
5490123 | Biver | Feb 1996 | A |
5901115 | Katzmann et al. | May 1999 | A |
6223050 | Roberts, Jr. | Apr 2001 | B1 |
Number | Date | Country |
---|---|---|
2001-42072 | Feb 2001 | JP |
2001-83268 | Mar 2001 | JP |
Number | Date | Country | |
---|---|---|---|
20040151072 A1 | Aug 2004 | US |