Horology: time measuring systems or devices – Time interval – Electrical or electromechanical
Reexamination Certificate
2001-02-05
2003-09-02
Martin, David (Department: 2841)
Horology: time measuring systems or devices
Time interval
Electrical or electromechanical
C368S010000, C368S011000, C368S111000, C368S112000, C368S113000
Reexamination Certificate
active
06614726
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stopwatch, and more particularly, to a stopwatch suitable for timing performed by a person for himself/herself.
2. Description of the Prior Art
An impact-responsive stopwatch (e.g., one disclosed in Japanese Patent Application Laid-Open No. Sho 63-127183) is known which is designed to enable a person taking part in a sport to measure and record time without a risk of a violent fall, and which is used in such a manner that the user gives an impact to the stopwatch by a striking action or the like to record or hold a split time at an intermediate point and to stop timing at a goal point.
However, there is a possibility of the stopwatch receiving impacts from various causes while engaged in a sport. For example, in a case where an impact-responsive stopwatch of this kind is used in a skiing downhill race, an impact may be caused by violent stock work or striking against a pole and may result in recording of an erroneous split time or termination of timing before the actual goal point is reached due to misidentification of an intermediate point as a goal point. Thus, it is difficult to perform timing in accordance with one's intention.
A technique for preventing an impact given in a predetermined time period after start of timing from being accepted as a split-time recording command in an impact-responsive stopwatch of this kind has also been proposed (Japanese Utility Model Application Laid-open No. Hei 5-59389). This technique, however, has the timing error prevention effect only during a predetermined period after a start of timing.
SUMMARY OF THE INVENTION
The present invention has been achieved in view of the above-described circumstances, and an object of the present invention is to provide a stopwatch having a highly reliable automatic timing function with a reduced possibility of timing being influenced by an external disturbance such as an impact.
A stopwatch of the present invention comprises:
measuring circuit for measuring a primary physical quantity;
storing circuit for previously storing as a target value the value of the primary physical quantity at a point where a time is to be recorded; and
recording circuit for recording a time count value at a time point where the measurement value measured by the measuring circuit coincides with the target value after the time measure is initiated.
The stopwatch of the present invention is provided with a measuring circuit for measuring a primary physical quantity and a storing circuit for previously storing as a target value the value of the primary physical quantity at a point where a time is to be recorded. It is therefore possible to ascertain whether the point, e.g., an intermediate point or a goal where a time is to be recorded has been reached or not, from the result of determination as to whether the measured value of the primary physical quantity by the measuring circuit has become equal to the target value. The stopwatch of the present invention is also provided with a recording circuit for recording a time count value at a time point where the measurement value measured by the measuring circuit coincides with the target value, after a time count has been initiated. Therefore, when the point, e.g., an intermediate point or a goal where a time to be recorded is reached, the measured time value at the corresponding time point can be recorded by the recording circuit without any operation by the user of the stopwatch. Thus, the desired time count recording can be performed without a risk of a violent fall or the like. Particularly, time count recording is performed on the basis of determination as to whether the measured value of the primary physical quantity has reached the target value, at the time point at which time recording is to be performed. As a result, the possibility of erroneous time recording caused by an external disturbance such as an impact is reduced.
In this specification, “recording by the recording circuit” includes not only storage in a memory, register and other storing circuit, but also display by display circuit. In some cases, it may be transmission of the time count value performed by using transmitting circuit to store the time count data in a remote place. Storage using the storing circuit may be a temporary or a permanent storage. In a case where only recording at a goal point may suffice, time display may be performed by using a liquid crystal display device or the like, time display may be performed simultaneously with storage by the storing circuit, or time data may be only stored by the storing circuit and may be read out afterward when necessary.
The primary physical quantity measured by the measuring circuit may be any physical quantity as long as it has a unique value at the point where time recording is to be performed after measurement is initiated. For example, to measure and record a downhill skiing time or a mountain bike running time, altitude or pressure is used as such a physical quantity. In a case where the altitude decreases monotonously from a starting point to a goal point, a split time at an arbitrary intermediate point may be uniquely measured. Even in a case where the altitude does not decrease strictly monotonously because of undulations at intermediate points between a starting point and a goal point, passing of an intermediate point or the goal point can be uniquely detected or measured as the altitude or atmospheric pressure at the point, provided that there is no other point having the same altitude as the intermediate point or the goal point. Typically, atmospheric pressure may be measured as altitude. However, a different physical quantity may be measured as altitude. The same can also be said with respect to measurement of a hang glider flight time or the like. In some cases, a plurality of physical quantities may be measured and a combination of the physical quantities may be selected to identify each of a plurality of points. For example, positional measurement with GPS may be used or combinedly used.
Preferably, the value of the primary physical quantity to be stored in advance by the storing circuit as a target value, i.e., the value of the primary physical quantity at a point such as an intermediate point or a goal at which a time is to be recorded, is a value measured previously (or preferably immediately before) at the point, with the measuring circuit of the stopwatch. In such a case, for example, even if there is an initial calibration error in the value measured by the measuring circuit of the stopwatch, a particular variation in the characteristics of the measuring circuit is directly reflected in the target value, so that the accuracy with which passage through the point is detected is high. Even if the primary physical quantity is one such as atmospheric pressure variable with respect to time, the influence of variation with respect to time is not considerable if it is in a short period of time.
In a case where the primary physical quantity at the point where a time is to be recorded can be supposed comparatively accurately on the basis of the measured value of the primary physical quantity at a point where time measurement is initiated, the supposed value at the point where time recording is to be performed may be computed on the basis of the value actually measured by the measuring circuit at the point where time measurement is initiated, instead of being previously measured at the point where time recording is to be performed. The supposed value thereby computed is stored as a target value by the storing circuit.
For example, the primary physical quantity (e.g., atmospheric pressure) may be measured at a time measurement initiation point (a starting point) by a measuring circuit, and an atmospheric pressure difference due to the difference between the altitudes of the measurement initiation point and the point at which a time measurement is to be made (such as a goal point) may be added to the measured value (atmospheric pressure value) after being corr
Milander Curtis
Yamasaki Masaharu
Lindinger Michael L.
Martin David
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