1. Field of the Invention
The present invention generally relates to interval timers and, more particularly, to a timer for measuring the duration of an activity, such as the practice on a musical instrument, even though the activity may be intermittent.
2. Description of the Prior Art
The accurate measurement of time has been central to many kinds of human activity. In early times, candles and containers which would allow the flow of a fixed amount of fluid or pulverent material through an aperture were ways of providing a relatively consistent indication of a predetermined interval. In modern times, although the so-called egg timer (a form of hour-glass) is still in widespread use, clockwork mechanisms as well as electronic (e.g. quartz) time bases have been developed for the indication of the lapse of a predetermined interval. However, such devices are not easily related to a particular activity unless they are also used to control that activity. Therefore, the most common application of such timers is to processes (e.g. cooking) or dispensing (e.g. lawn sprinklers) which typically proceed independently for a predetermined period when control by an operator is not anticipated.
So-called stop watches have allowed the extremely accurate measurement of the duration of an activity and can be provided with complex controls, such as so-called lap or split time indications so that a duration of a portion of a continuing activity can be observed while the measurement of the duration of the continuing activity remains ongoing. Such devices often include a provision by which the measurement can be halted for an arbitrary time and then resumed so that the cumulative time spent in the performance of an intermittent activity can be measured, independently of the interval during which the intermittent activity occurred.
However, stop watches require the active control of an operator and are ill-suited to use by the person performing the activity. They are also inaccurate to the extent that the operator's ability to control the stop watch is also inaccurate, particularly when the operator must actuate the timer, begin the activity, cease the activity, control the timer, etc. Thus they can substantially interfere with the performance of the activity unless special actuation arrangements are provided to provide actuator switches which are convenient to the activity, such as touch pads for swimming or light beam interruption for other athletic events.
It has been found by the inventor that these shortcomings of the prior art are particularly onerous as applied to activities or events which are associated with artistic expression or practice therefor, particularly since the manual operation of a timing device interferes with the mental concentration necessary to effectively conduct the activity. Further, especially as applied to the practice of music, the physical movements involved in the activity are irregular or subtle and cannot be easily sensed to control a timer. Also, while music practice is a training activity, not unlike athletic endeavors in some respects, the necessity for accuracy of cumulative elapsed time during which the activity is performed is even more critical since more subtle injuries may occur through overwork. Conversely, since music practice, by its nature, is extremely intermittent, the use of a timer which is not accurately controlled and merely measures the practice period can be very misleading as to the training effect of the practice and encourages bad and inefficient practice habits since time wasted during the practice period is not distinguished from actual practice time.