A system for measuring the accuracy of an internal timing source of a device having a light emitting display which is energized at a rate derived from the timing cycle of that timing source includes an optical pickup disposed for receiving light emission from one element of the display and generating a signal having the same frequency as the frequency of such light emission. In one embodiment, the pulses of that signal which occur within a given time period are counted and the number of such counted pulses is supplied to a display for human recognition. In a second embodiment, the time elapsed during one or more complete light emitting cycles is measured and displayed for human recognition. The pulses of a timing signal having a period of one microsecond which occur during one or more complete light emitting cycles are counted and the resultant count is displayed. A method includes the steps of comparing a time reference signal with a signal corresponding to the light emitting cycle of the light emitting display, determining the ratio of one parameter of the time reference signal to one parameter of the light emitting cycle, and displaying the value of either the ratio, a multiple of that ratio, or a submultiple of that ratio.
An apparatus for testing the accuracy of a timepiece comprising a television camera for converting the time displayed into an electrical signal, a means for converting the electrical signal into a digital signal, and a processing means for storing the digital signal and comparing the digital signal to a signal corresponding to a time standard. In operation, the time displayed on the timepiece is compared to the time standard at two different times and the difference between the time standard and the time displayed of the two measurements is compared.
A combination timepiece and electro-optic identification code device employs elements of the timekeeping display and has a programmable read only memory (PROM) storing a number of identification codes with means for selecting the code and transmitting it from the memory via an electro-optic display portion on the timekeeping display to an opto-electronic reader placed in proximity with the timepiece. The code selected may be unique to the device itself, may be selected by the user, and be a machine-readable code representative of the time, or may be a combination of any of the above codes.
Display apparatus for displaying the magnitude of a physical parameter includes a plurality of display regions each of which contains a plurality of electrically-operable display sections. The display apparatus also includes an electric circuit means responsive to an electric signal representative of the said magnitude which is arranged to operate the display sections in a cyclic manner in accordance with that magnitude. To this end, the electric circuit means is arranged, during a first period of each cycle, to effect operation of any display regions in which all sections therein require to be operated and, during a second period of each cycle, to effect appropriate operation of any other display region in which only at least one of the display sections thereof require to be operated.
A system for automatically time setting and message setting or programming of a cased digital watch or a watch module and including both an external setting unit and a serial interface control circuit inside the cased digital watch. The system in accordance with the invention is compatible with either watches that require time setting or watches that require both time setting and message programming and is applicable to any type of manually controllable watch. The time and message set system has a data entry unit that includes a keyboard, a display, a reference time module, a memory, a light source such as a light emitting diode or an LED array as an output and a processor which provides central control of the other functional units. The LED array output supplies coded messages to a light or energy responsive device or phototransistor in position under the face of the watch. The watch includes a novel circuit for responding to the phototransistor and provides time setting and message setting.
A refrigeration system contains a common compressor supplying refrigerant to a plurality of evaporators that are refrigerated and defrosted independently of one another. Individual refrigeration/defrost controls are provided in solid state form for the respective evaporators, and the individual controls are connected with a master control that prevents all of the evaporators from being defrosted at one time. The master control includes a digital time clock providing time signals to each of the individual refrigeration/defrost controls, and each of the individual controls can initiate a defrost operation for its respective evaporator on either a timed or demand basis. The master control includes a scanner that interrogates the individual controls in a special manner to initiate defrosting of the units in order of priority. The master control permits an individual defrost control for a selected evaporator to be tested in a timed mode by substantially increasing the speed of the time clock while operation of the remaining defrost controls is inhibited.
