Abstract: An inverter unit converts power from a solar battery into AC power and interconnects the AC power with a utility power supply. A control circuit manages the time during which the inverter unit stops. If the time is equal to or longer than a predetermined time, it is determined that one day has passed. Data for one day stored in a memory is accordingly cleared and data is newly stored in the memory.

Abstract: A solar powered GPS device for receiving GPS signals transmitted from GPS satellites in order to determine a time of day. The solar powered GPS device includes a housing that has an interior. A GPS assembly is mounted in the housing for receiving GPS signals from GPS satellites. A clock display is mounted on the housing for displaying a time of day. The clock display comprises a generally semitransparent material for allowing a light to pass through the clock display.

Abstract: An indicating plate for a timepiece is provided which is so structured as to prevent viewing of the solar cell and other items arranged thereunder through the indicating plate, which permits the same design expression as realized by the conventional metallic indicating plate and extensively increases a design variation inclusive of a ton (delicate hue) and pattern with superior-quality appearance and which has an excellent appearance quality to thereby ensure and enhance commercial value. The indicating plate for the timepiece is a timepiece indicating plate arranged on the front surface side of a solar cell housed in a timepiece. The timepiece indicating plate comprises a resin substrate through which light can be transmitted and metallic thin film layer coating formed on at least one side of the resin substrate by dry plating.

Abstract: In an electronic device having a solar cell and a unit driven by a power generated by the solar cell, the solar cell 10 includes a transparent substrate 12; a plurality of conductive portions 14a to 14d provided around the transparent substrate 12 and connected in series; and a plurality of photocells 18, each having a thin-line shape, formed at proper intervals on the transparent substrate 12 and connected to the conductive portions 14a to 14d. By forming a transparent electrode film 80 on the transparent substrate 12 and by connecting the transparent electrode film 80 to the ground, an adverse influence of static electricity is prevented.

Abstract: In a display device for an electronic apparatus, a circular polarizing plate constituted by a linear polarizing plate 42 and a ¼&lgr; plate 43 is provided between a solar display board 41 and a middle frame 46 for fixing a module 45 having a solar cell 44 to an outer case. As a result, a boundary line between the middle frame 46 and the solar cell 44, a gate track generated through injection molding of the middle frame 46, and further more, a solar cell element dividing line of the solar cell 44 cannot be seen. Consequently, a variation in design of the solar display board 41 can be increased. Moreover, the color of the solar display board 41 is deepened so that a feeling of high quality can be obtained as goods, and the provision of the middle frame can provide various external shapes of a watch in respect of the design.

Abstract: An indicating plate for a solar watch, comprising a color diffusion plate which, by virtue of the presence of a coloring agent, a coloring light diffusing agent, a colored translucent substrate, a pattern layer/colored thin film layer and a diffusion layer, is adapted to transmit a portion of light having a wavelength within a range capable of causing a solar cell housed under the indicating plate to generate power. The color diffusion plate is adapted to make it difficult to view the solar cell from the outside through the indicating plate and is also adapted to impart a color tone to the indicating plate.

Abstract: There is described a colored photovoltaic cell (1) with a semiconductor, preferably silicon, which has high efficiency and a pleasing colored appearance, allowing it to be used as a dial for a watch or another electronic apparatus powered by the cell. The cell includes a reflective metal substrate (2) serving as the bottom electrode, a stack of hydrogenated amorphous silicon layers forming p-i-n junctions (8), and a transparent top electrode (9). The latter may be coated with a layer (16) of slightly diffusing lacquer, which may be colorless or colored. The respective thicknesses e1 of the top electrode and e2 of the silicon are combined as a function of the refractive indices of the materials so as to produce an interferential reflection in a predetermined reflection spectrum.

Abstract: An object of the invention is to provide a solar battery module having a high efficiency power generating ability, a harmony of design without an odd sensation, and a freedom of design. The object is achieved by a solar battery module comprising, on a light-receiving surface thereof, a photoelectric conversion section for converting incident light into electricity, the photoelectric conversion section comprising silicon, and an insulating color film disposed in regions other than the photoelectric conversion section for reducing a color difference from the photoelectric conversion section.

Abstract: To provide a portable electronic device which is easily shifted into a power save mode at the discretion of an operator, such as a user, and optimally reduces power consumption in accordance with the current use of the device. An operator can force an electronic device into a power save mode at the operator's discretion by manipulating a control. Electrical energy stored is thus reliably saved in accordance with the usage by the operator, and unnecessary power consumption is efficiently reduced, even more than in a method in which a device automatically stops the time display and is shifted into a power save mode in accordance with the presence or absence of power generation. Setting a time limit within which the operational state of the control needs to be complete, the operator is prevented from erroneously shifting into the power save mode, and the ease of use of the time measurement device is still assured.

Abstract: The present invention concerns an electric timepiece, in particular a wristwatch, supplied with electric current by an accumulator (16) intended to be recharged once flat, this timepiece (1) including a time-setting stem (4) and at least one control member (6) for at least one horological function of said timepiece (1), characterised in that the time-setting stem (4) is electrically connected to one of the poles (18) of the accumulator (16), and in that the control member (6) can be electrically connected to the other pole of the accumulator (16) after said member has been pressed. The present invention also concerns a timepiece of the type-described above, this timepiece (1) including at least a first and a second control member (6′) each controlling at least one horological function of said timepiece (1), characterised in that each of the first and second control members (6′) can be connected to a respective pole (18, 20) of the accumulator (16) after said member (6′) has been pressed.

Abstract: In the case of using a solar battery formed by growing an amorphous silicon film on a substrate as a watch face for an electronic watch, there had been great restrictions with regard to the design of the watch face. If it is possible to impart transparency to light to the substrate onto which is formed a solar battery, so that it is possible to achieve a form of solar battery that is not perceivable, it is possible, by using a substrate onto which is formed this solar battery either on the watch face or on a protective glass crystal or the like, to achieve a watch with a solar battery not restricted with respect to watch face design.

Abstract: The present invention provides a timepiece having a light-receptive/emitting device such as a solar cell and an EL device in which a parting portion can be set freely and the timepiece can be adapted to various design requests. The timepiece has a dial for displaying a time, a timepiece movement incorporating driving units, a light-receptive/emitting device provided between the timepiece movement and the dial, and an armoring member for housing the timepiece movement, in which a portion or a whole of the dial is formed to have a light-transmitting property so as to supply outside light to the light-receptive/emitting device or to allow the light-receptive/emitting device to emit light to an outside, the light-receptive/emitting device is fixed to one side of the timepiece movement, and the dial is mounted to the armoring member by engaging a first portion formed at the dial with a second portion formed at the armoring member.

Abstract: In an electronic timepiece, in which electric power generated by a solar cell (101) is accumulated in an accumulator device (104) and a time keeping means (105) is driven with the accumulated electric power, an electrically on-off controllable switch (102) is provided in a circuit for charging the accumulator device (104) by the solar cell (101), a voltage comparison means (103) intermittently brings the switch (102) into the off-state at predetermined intervals and compares the generated voltage (Vs) by the solar cell and the accumulated voltage (Vb) in the accumulator device (104), and keeps the switch (102) in the off-state as it is when Vs≦Vb and brings the switch (102) into the on-state when Vs>Vb in accordance with the comparison result. Thereby, a reverse flow of an electric current from the accumulator device (104) can be prevented and a voltage drop on charging is eliminated, resulting in enhancement in charging efficiency.

Abstract: An electronic eternity clock is powered by solar cells. The LCD segment display is shut down during the night by the use of a sensing circuit utilizing sampling pulses from an associated microcontroller which turns a transistor on and off which is connected to a floating ground between the solar cell and an isolating diode, both series connected across the rechargeable battery.

Abstract: A display device and an electronic watch permit various information to be clearly distinguished from a background when a solar battery is placed within a display area for displaying the information. A display device and the like include a polarizer, a liquid crystal layer, a polarization separating film, and a solar battery. The polarization separating film operates to transmit linearly polarized light polarized in one direction and to reflect other linearly polarized light. Since the surface of the solar battery has a dark color, such as black, a dark-colored background is displayed by light traveling along an optical path. Information, such as numbers, is displayed in a light reflection color by light that is reflected by the polarization separating film and travels along an optical path. The information, such as numbers, is displayed in a light reflection color.

Abstract: The invention concerns a dial, in particular for a timepiece, formed of a solar cell including a substrate, at least one plurality of superposed layers defining at least one n-i-p or p-i-n element and a conductive layer forming a first electrode arranged to be exposed to luminous radiation, characterised in that said electrode is formed of a partially reflective metal layer.

Abstract: In a solar-powered, radio-controlled timepiece an incorrect display can occur before the operating voltage definitively falls below the switch-off level if each pulse for the electromechanical transducer is no longer sufficient for advancing the display. A step monitor senses such an insufficient pulse and triggers a reset command in order to switch on the radio signal receiver for automatically correcting the hands position to the absolute time which is decoded from the current time telegram.

Abstract: An electronic watch is formed of a case body having a display window, a movement situated in the case body, a light transmitting digital display disposed above the movement in the case body to be observed from an outside through the display window, and a solar cell unit. The solar cell unit is interposed between a part of the light transmitting digital display and the movement, and a reflecting plate is disposed under another part of the light transmitting digital display adjacent to the solar cell unit. Also, a light transmitting material is interposed between the part of the light transmitting digital display and the solar cell unit. Thus, light is supplied to the solar cell unit from the outside through the light transmitting digital display.

Abstract: An Electronic clock having an electric power generating element which is operable even in a state where the voltage of the electric power generating element is low. The electronic clock includes an electric power generating element, a low-voltage oscillating circuit which can oscillate even with a low voltage with the electromotive force developed by the electric power generating element as a power supply, an electronic clock movement having signal generating means, a voltage detecting circuit that detects an output voltage of a charging circuit, a selecting circuit that selects any one of the output signal of the low-voltage oscillating circuit and the output signal of the signal generating means on the basis of the voltage detection result to output it, and a step-up circuit that inputs an output signal of the selecting circuit and a voltage from the electric power generating element for stepping it up to output a stepped-up voltage to the charging circuit.

Abstract: In an electronic watch provided with an electric power generator (1) for generating power from external energy and charge means (3) for charging power generated by the electric power generator (1), clock means (4) executes time display operation by power of the electric power generator (1) or charge means (3) and produces a count pulse (S10) for counting the amount of power stored in the charge means (3) and a charge monitoring means (6) counts the amount of stored power of the charge means (3) in response to the count pulse (S10) and displays the amount of stored power based on the counted value.

Abstract: A charging type electronic timepiece of the present invention is configured such that a return to a correct time display is achieved after the recovery of the voltage on the basis of time information held by a circuit in case the power-supply voltage has dropped to such an extent as to prohibit a motor drive without causing any interruption of oscillation (a stop of issue of reference signals) and such that in case the extent of the voltage drop is such as to cause an interruption of oscillation, a stop alarm display is given first after the voltage recovery through a storage of the fact of the interruption of the circuit since correct time information is no longer expected to be held by the circuit. This allows the charging type electronic timepiece to minimize the inconvenience that the user must perform a time adjustment and to securely inform the user of a true necessity of time adjustment through a display of its information.

Abstract: A combination electronic watch equipped with an optic power generating unit is provided, wherein a solar member and a liquid crystal member 4c are overlapped one onto the other and windows 4c are formed on the solar member so that a digital display will become possible at any location on the watch display surface and warnings for charging will be simultaneously provided by both the analog display of hands and the digital display.

Abstract: The present invention provides a solar-battery-mounted display structure which comprises a solar battery (16) having a light-receiving surface (16a) disposed in a displaying portion, a light-transmissive plate (17) disposed on the front side of the light-receiving surface and having a predetermined light-transmittance, and an coating layer (20) formed on the back surface of the light-transmissive plate such that the solar battery can securely generate at least a predetermined amount of electric power. Since an coating layer is formed on the back surface of the light-transmissive plate, no coating layer is necessary on the light-receiving surface of the solar battery. Due to this, consideration of suitability of such a coating layer to the light-receiving surface is not required, and discarding or exchange of the solar battery due to defects in such a coating layer is not required.

Abstract: A dial, in particular for a timepiece, formed of at least one regenerating photoelectrochemical type solar cell including a first substrate intended to be exposed to the light and a second substrate carrying on their opposite faces electrodes between which is arranged a physico-chemical system capable of absorbing light and generating an electric voltage across the terminals of said electrodes, characterised in that said first substrate is formed of a translucent material.

Abstract: A display device comprising a photovoltaic (PV) panel adapted to simultaneously produce electrically needed to operate a display and form either the background or foreground of the said display. The PV panel comprises large continuous sheets of PV material provided with one or more openings. Either light for the display or the display mechanism itself pass through the openings in PV material. The device may include a computer or electrical circuit which will activate the display device responsive to temperature, moisture, light conditions or to a remote signal such as a pager.

Abstract: The present invention is an alarm clock device which programmably and automatically coordinates the movement of one or more electric toy trains, or the like. The present invention alarm clock preferably triggers the movement of an electric toy train when a pre-set alarm time is reached. The alarm clock device comprises at least one base that defines an elongated substantially non-linear track for regulating the movement of a toy train. The traveling speed of the train is preferably regulated by a voltage varying device, such as a transformer, that is attached to the track and also coupled to a manually adjustable speed controlling member within the alarm clock. The movement of the train is preferably accompanied by applicable audible sounds that correspond therewith. The duration of movement may be programmed manually and may be adjusted in any variety of ways.

Abstract: The present invention relates to a display device which is used for various types of electronic apparatuses, e.g., an electronic watch, an electronic pocket notebook, and the like, and an electronic device. In the device or apparatus, a solar battery member having a lot of light passing openings for passing light is provided between a liquid crystal display member and a plate-like light emitting member disposed at a position lower than that of the liquid crystal display member.

Abstract: A solar-cell watch dial to be disposed on or above a solar cell housed in a watch, the solar-cell watch dial comprising an alumina of the formula Al.sub.2 O.sub.3 whose purity is at least 99.90% and exhibiting a light transmission ranging from 40 to 60%. The invention also includes a process for producing a solar-cell watch dial, which comprises the steps of: mixing together an alumina of the formula Al.sub.2 O.sub.3 whose purity is at least 99.90%, an organic binder and water to thereby obtain an Al.sub.2 O.sub.3 mixture (A); drying and granulating the Al.sub.2 O.sub.3 mixture to thereby obtain a granular material (B); molding the granular material into a plate dial precursor (C); firing the dial precursor at 700 to 1500.degree. C. in atmospheric environment to thereby obtain a preliminary firing product (D); and firing the preliminary firing product at 1500 to 1800.degree. C. under a pressure of 1.times.10.sup.-2 to 1.times.10.sup.-5 torr for 1 to 10 hr to thereby obtain a solar-cell watch dial (E).

Abstract: In an electronic appliance equipped with a light emitting apparatus 30, a transparent sheet member 31 having a character, a pattern or other symbols is arranged on a front surface of a transmission type flat-shaped light emitting apparatus 32. A colored sheet member 33 is arranged behind this light emitting apparatus. Openings 21 are formed in the colored sheet member 31, the light emitting apparatus 32, and the transparent sheet member 33. These openings are communicated therethrough. A pointer shaft 19 and 20 of a gear train mechanism 17 for indicating a present time is penetrated through the openings. Hands 22 and 23 are rotatably driven above the transparent sheet member 31. When the light emitting apparatus 32 is turned OFF, the colored sheet member 33 can be observed through the transparent sheet member 31 and the transparent light emitting apparatus 32. Accordingly, the colored sheet member 33 may provide high-grade quality and decorative feelings.

Abstract: The dial plate according to the present invention comprises a substrate formed of a ceramic material and a colored coating layer formed on the substrate. And, the colored coating layer is characterized by having a colored layer formed of a ceramic paint containing a metal compound as a principal component. The substrate formed of a ceramic material is porous; and hence, diffuses incident light to conceal a solar battery placed on the backside from view. Since the colored layer is formed of a ceramic paint containing a metal compound as a principal component, it is easy to firmly attach it to the substrate formed of a ceramic material and it is capable of forming various colors corresponding to the types of metal compounds applied.

Abstract: In an electronic timepiece using power supply means consisting of a solar cell and an electric double layer capacitor, whose output voltage varies, as a power supply, a plurality of driving pulse preparation means for preparing driving pulses for driving a stepping motor are arranged. Each driving pulse preparation means prepares a driving pulse group having a combination of pulse widths, which combination is different from that of remaining ones of the driving pulse preparation means. A varying output voltage of the power supply means is detected, and one of the plurality of driving pulse preparation means is selected in accordance with the detected output voltage. A driving pulse for minimizing the current consumption is selected and supplied to the drive circuit of the stepping motor. With this arrangement, the stepping motor can always be driven at a minimum current consumption, and the driving time can be prolonged.

Abstract: A thermoelectriocally powered wristwatch has an endothermic plate affixed to the underside of a case back for absorbing external heat, and a thermal conduction plate for conducting the absorbed heat through heat transfer pins to a thermoelectric conversion element which converts the absorbed heat to electricity for powering the wristwatch. Thermal conduction preventive packings formed of a material having low thermal conductivity, such as plastic or rubber, are interposed between the endothermic plate and the case back and between the case back and the thermal conduction plate.

Abstract: A display unit structure for an electronic device is formed of a solar cell, and a display unit. The display unit includes a transparent base layer disposed on the solar cell, and a hologram layer laminated on the base layer and having a virtual mirror plane for reflecting a light with a predetermined wavelength. The virtual mirror plane of the hologram layer is inclined with respect to front and back surfaces of the hologram layer. Thus, the light with the predetermined wavelength is reflected by the hologram layer, and light other that the predetermined wavelength is transmitted to the solar cell.

Abstract: The electronic watch according to the invention comprises an energy source 1 (power supply), storage circuit 3, clock output unit 4, constant voltage circuit 5, voltage detection circuit 6, switching circuit 8, and control unit. The energy source 1 transforms external energy into electric energy and supplies a power supply voltage. The storage circuits 3 stores the power supply voltage or a booster voltage of the power supply voltage and thereby supplies a storage voltage. The clock output unit has a watch system and a condenser of a small capacitance, receives any of the power supply voltage or the booster voltage, and the storage voltage, and supplies a plurality of logic signals. The constant voltage circuit 5 generates a reference voltage from the clock voltage. The voltage detection circuit 6 compares the power supply voltage or booster voltage, storage voltage, and clock voltage selectively with a voltage set on the basis of the reference voltage and supplies a voltage detection signal.

Abstract: A covering member (4), a solar battery (3) and a hand-operating mechanism-containing movement (2) are housed inside a case (1) which has a front side opening (1a), a glass (5) which is provided in the front side opening (1a), in the order of these constituents from the face side of the case (1). The solar battery (3) is disposed opposite to the glass (5) at a light receiving surface thereof which is covered with the covering member (4). The covering member (4) can also serve as a dial. If the covering member (4) is molded out of ceramic, it can provide the dial with a white appearance, so that light can sufficiently be transmitted to the receiving surface of the solar battery (3) owing to the light transmittance of the ceramic.

Abstract: An electronic time piece senses and warns the electric residue of a secondary cell having electrodes of conductive polymer to a user during the rapid charge.The electronic time piece converts a kinetic energy produced by the user's motion into an electric energy. The electric energy is then outputted from a power generator coil as a charging voltage for charging a chemical reaction type secondary cell. The charged energy in the secondary cell is used to actuate a time piece circuit for indicating the time.The electronic time piece comprises an electric residue sensor unit which outputs an electric residue detection signal when the voltage in the secondary cell continues to exceed a reference voltage corresponding to an electric residue in the secondary cell for a predetermined time during the rapid charge.

Abstract: An analog indication type electronic timepiece includes a power generation device for transforming kinetic energy produced by motions of a user into electric energy and for causing the electric energy to output from a magnetic coil as an electric charging energy; a secondary power source charged by said electric charging energy; a timepiece circuit driven by a charged energy from said secondary power source to output motor drive pulses; and a drive motor including a drive coil and a drive rotor rotatably driven when the drive coil is energized by said motor drive pulses.

Abstract: A split battery contact arrangement (10) for a low voltage portable electronic product having a first circuit (18) and second circuit (18) comprises a split positive battery contact having a first positive contact point (20) selectively isolatable from a second positive contact point (17), the first positive contact point being coupled to the first circuit (18) and the second circuit (16) being coupled to the second positive contact point. The arrangement further comprises a back-up energy source (24) coupled to the first positive contact point and a removable battery (12), which when removed selectively isolates the first circuit from the second circuit, thereby preventing the back-up energy source from powering the second circuit. When the removable battery is inserted, it couples the first circuit to the second circuit.

Abstract: The present invention provides a horological piece (P) comprising an energy source having at least one photovoltaic cell (1) capable of transforming luminous radiation into an electrical current. This photovoltaic cell includes an active surface (F) sensitive to luminous radiation. A horometrical movement (56) is supplied by the energy source and is capable of supplying time keeping information. A display (58) is adapted to receive the time keeping information supplied by the horometrical movement (56) and displays this information so that it is readable by a user. The active surface (F) of the photovoltaic cell (1) has at least one transparent region which at least partially covers the display (58). The invention may be applied to horological pieces without portable power sources, such as a battery.

Abstract: A hearing aid employs a permanent built-in rechargeable storage cell or battery, and a solar cell or other photo cell which powers the electronics of the hearing aid and recharges the storage cell. Favorably, a thin film amorphous silicon cell is employed, and is affixed onto an outward-facing surface of the aid. The photocell is connected in parallel with the storage cell and is of sufficient power capacity to power the amplifier and recharge the storage cell under average ambient light conditions. The storage cell is favorably of sufficient capacity to power the amplifier for at least several hours under darkness conditions.

Abstract: It comprises a standard electronic movement (13) held in the case (1) by means of an encasing ring (15) made of synthetic material and also containing a large-sized accumulator (30) gripped between two conductive plates (16, 29). The upper plate (16) is covered with an insulating film (18) pierced with a hole (19), through which the blade (14) of the battery receptacle of the movement comes in contact with the plate (16). The other pole of the accumulator is connected to the movement by means of the base (3), the case (1) and the dial (10). The encasing ring (15) carries photovoltaic cells (21) illuminated through indentations (22) of the dial. The timepiece can advantageously be produced in small series, and its power reserve is very high.

Abstract: A barrel spring winding device comprises a solar cell (3) arranged to receive ambient light, a capacitor (4) connected to the terminals of the cell, a stepping motor (6) and a control circuit (5). The input of the circuit is connected to the terminals of the capacitor and its output to the terminals of the motor. The rotor of the motor is operatively connected to wind a barrel spring, for example of a watch. The cell (3) charges the capacitor (4) and when the voltage thereof, measured by a differential amplifier (23), reaches a reference voltage (V.sub.r), the capacitor is connected to the terminals of the motor by a switching transistor (27). Discharge of the capacitor supplies to the motor a drive pulse whose duration is determined by a one-shot flip-flop (25). After the pulse, the capacitor is once again charged by the cell. To prevent the motor from receiving a drive pulse before it has stopped, i.e.

Abstract: A ballpoint pen of conventional size and shape has a movable ball point that is pressed upwardly in the direction of the housing of the pen when a mark is made. Means is provided for normally biasing the ballpoint outwardly of the housing. However, when the ballpoint is pressed against a writing surface, the refill cartridge having the ball at the lower end thereof is moved upwardly to close a normally open switch which connects a solar cell array in circuit with an electronic counter that counts each time the switch is closed. Controlled by the counter is a liquid crystal display that visually indicates the total number of counts. A gravity switch is contained in the housing and is actuated to reset or clear the counter in preparation for counting a succeeding group of marks when the pen is inverted.

Abstract: A solar powered electric clock of the type configured as a traditional 400-day clock with a torsional pendulum includes a housing in which the clockworks, dial face and hands are disposed. The housing is supported over a base by means of vertical columns. Solar cells are mounted in a top surface of the base, along with a storage capacitor. No battery is required. A radio signal receiver mechanism for setting the time in response to external radio signals can be provided and mounted in the housing or base. A pendulum drive mechanism can be mounted in the housing or base. The clockworks is driven by a motor which can be mounted in the housing or base.

Abstract: A self-chargeable timepiece includes a pair of small and large capacitors having respective small and large capacities and selectively disconnectably connected at their respective terminals to time-keeping circuitry and a solar cell. The pair of small and large capacitors cooperate with each other during the momentary operation of the solar cell for selectively receiving and storing the electric charge to develop respective terminal voltages across their respective terminals even after the momentary operation of the solar cell. A detector periodically detects the terminal voltages of the small and large capacitors during the time-keeping operation. A switching circuit responds to the detected terminal voltages for selectively connecting and disconnecting the small and large capacitors to and from the time-keeping circuitry to enable the small and large capacitors to selectively power the time-keeping circuitry.

Abstract: In an electronic timepiece powered by a photovoltaic cell, the supply voltage fluctuates a great deal due to the varying amounts of light received by the photovoltaic cell. This presents special considerations for a low voltage alarm circuit. The present invention combines two alarms. First, there is a charging alarm which responds to voltage and which indicates that voltage is low and that the amount of light should be increased. If the light is increased, the circuit will continue to operate and no reset operation is needed. If on the other hand the voltage drops to the point where the circuit actually stops, a stop alarm is activated. The stop alarm is not responsive to voltage level. Instead, it is responsive to the fact that the circuit's oscillator has stopped. Furthermore, the stop alarm is provided with a memory and it will not automatically be reset if the voltage is increased.

Abstract: A solar powered electronic clock has a display, time-keeping electronics, a battery, and a solar cell array. The battery is chargeable from the solar cell array and supplies only the time-keeping electronics while the display is powered only by the solar cell array. A diode connected between the solar cell array and battery permits the battery to be recharged, but prevents the display from drawing energy from the battery.

Abstract: A timepiece has a stepping motor for intermittently rotating hands to indicate the time, a solar cell for temporarily generating electric charge and capacitors for storing the generated electric charge to supply an operating voltage. A drive circuit repeatedly applies a combination of first and second consecutive driving pulses having electric powers proportional to the operating voltage to the stepping motor, while a detector detects the operating voltage. A control circuit is connected between the drive circuit and the detector for controlling the detector to effect the operating voltage detection after the application of the first driving pulse and before the application of the following second driving pulse. When decrease of the operating voltage is detected after the application of the first driving pulse, the operating voltage is increased before the application of the following second driving pulse so as to ensure the rotation of the hands.

Abstract: To increase the utilization by an electric timepiece, such as a quartz watch, of the electric energy derived from a primary source, such as a photo cell, which energy is stored in a multi-layer capacitor, the voltage on the capacitor is fed to transfer capacitors which are connected in series or in parallel to be charged from the multi-layer capacitor and then connected in series or in parallel to charge an auxiliary capacitor which drives the movement of the timepiece. Provisions are made for starting the watch when the stored voltage is less than the operating voltage of the watch movement.

Abstract: An electronic timepiece including timekeeping circuitry and a primary power source for converting externally applied energy to electrical energy for powering the timekeeping circuitry. The electronic timepiece also includes a secondary power source for storing energy from the primary power source and powering the timekeeping circuitry. A power controller, coupled to the timekeeping circuitry, primary power source and secondary power source controls the source of power of the timekeeping means so that upon the application of external energy to the primary power source, when the timepiece is not operating in the secondary power source and cannot power the timekeeping circuitry the timepiece begins operating substantially simultaneously.