Citizen Watch Company, Ltd.

Takashi Yamada

Fukuo Sekiya

Heihachiro Ebihara

Kazunari Kume

Heichachiro Ebihara

An electronic timepiece having a first display unit which indicates the present time by means of digital values, and a second display unit of the hand type which displays the time set by an additional function such as alarm function by means of one or more hands.

Electronic timepiece

A portable electronic device with calculation and timekeeping functions, equipped with a keyboard for calculation and time setting purposes, means for producing scanning signals when a key is actuated, these signals being applied to switching elements connected to rows of keyboard contacts. When a key is depressed, the resultant high level signal potential applied to the corresponding contact row causes the row position to be detected and stored in a first memory circuit, which produces a signal causing the corresponding contact column to be detected and stored in a second memory circuit. Actuation of an external control member causes a signal to be stored by a reset signal in a first stage memory circuit which produces an output signal to be subsequently stored in a second stage memory circuit in synchronism with a timing signal. The low frequency and low duty cycle of the scanning signals and reset signal ensure minimized power consumption and suppression of switch bounce effects.

Portable electronic device equipped with calculation and timekeeping

A system for signalling the termination of the lifetime of a battery for an electronic timepiece is disclosed. The system includes a hand display device, an electro-optical display device, a battery voltage detecting circuit adapted to produce a signal when voltage of the battery lowers below a predetermined value, and means for modulating the time display pulse to be applied to one of the display devices in response to the signal generated in the battery voltage detecting circuit, thereby to modifying the time display for informing the end of the battery lifetime.

System for signalling the termination of the lifetime of a battery for

An electronic timepiece having both time indicating hands and an electro-optical time display, wherein individual digits of the electro-optical display can be selected for correction and wherein correction of a digit causes the time indicating hands to advance by a precisely corresponding amount.

Electronic timepiece having an analog display device and a digital

A portable electronic device equipped with timekeeping circuit means for providing at least units of seconds and tens of seconds of time information, and display means for displaying said time information in digital form, which comprises first external control member for inputting numeric data signals, a control circuit for selecting at least said tens of seconds of said time data for correction, second external control member for inputting control signals to actuate said control circuit, first gate means for applying said numeric data signals to said timekeeping circuit means to effect correction of at least said tens of seconds of time information, second gate means for automatically resetting said units of seconds of time information to zero in response to correction of said tens of seconds of time information.

Portable electronic device

An electronic timepiece having both an electro-optical time display and time indicating hands, and means for setting both the electro-optical display and the hands to display an identical initial time value and to be thereafter advanced in synchronism with each other.

An electronic timepiece having improved means for rapid setting of time, date or alarm time, whereby the number of setting pulses generated for each actuation of an external actuating member is varied depending upon the time intervals between successive actuations.

Time correction system for an electronic timepiece

A portable electronic device including a battery power supply, an oscillator for generating a time base signal, a timing pulse generator for generating timing pulses from said time base signal, shift registers for operations, and a display device for displaying the content of said registers, characterized by the provision of means for initiating and halting the operation of the timing pulse generator without disconnecting the power supply.

Portable timepiece calculator with power savings feature

Drive signals are applied to the segment and digit electrodes of a liquid crystal display device in a time-multiplexed manner by means of a control circuit adapted to control first and second gates the output of one of which is selected as a segment signal by selection means, and further adapted to control a digit signal generating circuit for producing a digit signal that cooperates with the segment signal to drive the display. The effective application of drive signals allows a reduction in the number of segment electrodes and in the quantity of associated wiring so that the degree of integration on an IC chip can be increased.

Drive system for liquid crystal display device

A data transfer circuit consisting of a shift register circuit, which is efficiently applicable to portable electronic devices such as a portable electronic timepiece, electronic computer or the like is disclosed. The circuit comprises a first shift register circuit and a second shift register circuit to which is transferred data from said first shift register circuit. The second shift register circuit includes at least first stage bit whose data transfer is controlled by two phase clocks and another bit whose data transfer is controlled by one phase clock.

Data transfer circuit

A portable electronic device equipped with timekeeping and calculation functions, time and calculation data being stored in semistatic shift registers. Time data is circulated once per second through a loop containing two full adders with units of seconds being incremented by one in each circulation by the first adder and digit carry operations performed by the second adder and by a bit set/reset circuit during the same circulation. Units of seconds digit of displayed time data corresponds directly to least significant digit of stored time information.

Portable electronic device equipped with timekeeping and calculation

There is disclosed an input circuit for portable electronic devices comprising an exteriorly operable member for delivering an operating signal to a portable electronic device and including a first flip-flop set in synchronism with an edge of said operating signal, a second flip-flop for reading therein said operating signal and a reset signal preparing circuit supplied with an output from said second flip-flop and preparing a reset signal for said first flip-flop.

Input circuit for portable electronic devices

An electronic timepiece comprising a counter circuit adapted to present reference data indicative of an existing year, month, date and day of the week, and operative to count leap years, years, months, dates, and days of the week at a high speed with a preset reference data as a starting point, a register for storing calendar data indicative of a desired year, month, date and day of the week to be determined, a comparator for comparing the content of the counter circuit and the content of the register and generating a coincidence signal when the contents are in agreement, and a controller for halting counting operation of the counter circuit in response to the coincidence signal to cause a display device to display the contents of the counter circuit to obtain an indefinite item concerning calendar.

Electronic timepiece with calendar function

A portable electronic device equipped with a timepiece circuitry, which electronic device comprises a plurality of numeric keys adapted to provide numeric values correponding to 0 through 9 when actuated. The numeric keys are utilized to correct a selected digit and once the numeric keys are actuated to complete a correction of the selected digit a shift will be made from the selected digit to another digit for a correction. The digit to be corrected is identified by a decimal point display segment which is automatically and cyclically shifted.

An electronic device having means for display of data in digital form and means for suppression of non-significant zero digits, which comprises storage circuit means for storing and circulating said data, detection circuit means coupled to an output terminal of said storage circuit means for detecting zero value digits in said data, counter circuit means responsive to an output signal from said detection circuit means for counting the number of non-significant zero value digits in said data, and gate circuit means coupled between said storage circuit means and said display means responsive to an output signal of said counter circuit means for suppressing display of said non-significant zero value digits by said display means.

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Sayama, Japan

Takashi Yamada