Citizen Watch Company, Ltd.

Mitsuo Sekine

Yasuhiko Nishikubo

Shingo Hashimoto

Sizuo Yamaguchi

A voltage sensing circuit is disclosed, which utilizes a reference voltage generating circuit for producing a reference voltage whose value is determined as a function of absolute temperature, independent of circuit element variations, the reference voltage being generated by means of a pair of MOS field effect transistors having different values of Id/K, where Id is drain current and K is the channel pattern ratio W/L.

Voltage sensing circuit

A temperature sensing device is disclosed which utilizes a temperature sensing circuit which generates a voltage whose level varies linearly in accordance with temperature, this voltage being produced using a pair of MOS field effect transistors which have different values of the ratio Id/K, where Id is drain current and K is the channel pattern ratio of channel width to channel length.

Temperature sensing device

An analogue electronic timepiece is described having an oscillator, a frequency divider, a hand display means, an hour and minute circuit for counting the output of the frequency divider, and an alarm setting circuit. An equality checking circuit adapted to compare the output of the hour and minute circuit with the output of the alarm setting circuit to produce a coincidence signal. An alarm device is operated by the coincidence signal, gate means, and a manual switch. The gate means is so arranged to produce a signal for setting an alarm time in the alarm setting circuit in accordance with the closing of the switch.

Analogue electronic timepiece with an alarm device

In an electronic timepiece having an analog type of time display by means of hours and minutes hands, an alarm system is provided which functions electronically and independently of the analog display system. An alarm signal is generated when the time duration counted by an alarm timekeeping circuit coincides with an alarm time stored in an alarm time memory circuit, said alarm time being set by the timepiece user actuating a switch.

Electronic timepiece having an alarm system

An electronic alarm timepiece comprises a quartz crystal oscillator, a frequency divider, a display driving means, a display means, an alarm signal shaping means and an alarm means. The alarm signal shaping means is so arranged that a pair of output signals which are opposite in phase are produced with the aid of output signals of the frequency divider for actuating the alarm means, whereby it is possible to provide an alarm signal shaping means in the form of a complementary metal oxide semiconductor (CMOS) integrated circuit having sufficient power to actuate the alarm means without other amplifying circuits.

Electronic alarm timepiece

In an electronic timepiece equipped with an alarm function, an alarm time memory circuit is provided for setting in an alarm time by actuation of an external control member and another memory circuit is provided into which an advance warning time period can be set and stored. Means are provided for detecting coincidence between the current time and an advance warning time comprising the difference between the memorized alarm time and the advance warning time period, to provide an advance warning signal prior to the actual alarm time. Parallel computation is used to generate said advance warning time, and the advance warning time period can be continuously displayed.

Electronic timepiece equipped with alarm function

An electronic digital stop watch including means for generating a time standard signal, a display device for indicating the time lapsed from the start operation and alarm control means provided for presetting a desired alarm time and for generating an audible alarm signal when the lapsed time becomes equal to the preset time.

Electronic digital stop watch

A frequency adjusting circuit for digitally adjusting the frequency of a time reference signal consisting of a series of pulses is disclosed. The circuit function to adjust the frequency of said series of pulses by subtracting or adding a given number of pulses from or to said series of pulses for a time set beforehand every time upon receipt of a predetermined number of pulses of said time reference signal.

Frequency adjusting circuit

In a driving circuit for an electrochromic display device of the type wherein a clock signal is applied to the common electrode segment, and a driving signal having a different level from that of the clock signal is applied to the display segment electrode in response to the clock signal and a display decoder output, thereby effecting display and termination thereof by using a single source, gate circuit means is provided for preventing short-circuiting of the electrodes caused by the delay time between the clock signal and the driving signal.

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Tokorozawa, Japan

Mitsuo Sekine