Citizen Watch Company, Ltd.

Katsuyoshi Aihara

Ryoji Iwakura

Daisuke Yamada

Makoto Watanabe

Takakazu Yano

Takaaki Nozaki

Daisuke Matsuoh

Ryutaro Uemura

Shinichi Komine

Yukio Otaka

An analog electronic watch includes watch's internal time, and controls rotation of a group of indicators based on the watch's internal time. A terminal appliance stops the rotation of the group of indicators, generates an image of the indicators and the dial plate with an imaging unit, detects current display positions of the group of indicators in identification areas as part of the image of the indicators and the dial plate, generates current display time information based on the current display positions, and generates display time correction information based on a difference between the current display time information and the watch's internal time information. The analog electronic watch corrects the display positions of the group of indicators based on the display time correction information. There are provided an analog electronic watch system and an analog electronic watch that can reduce a time required for display time correction.

Analog electronic watch system and analog electronic watch

Charging a storage cell requires the electromotive force exerted at a photogenerating cell in addition to the voltage equal to or higher than the forward on voltage developed at an backflow preventing diode. Therefore, the charging is inefficient. Moreover, the area of the backflow preventing diode must be large in consideration for a current supply from the photogenerating cell at a high intensity of illumination. A charging circuit, constructed using a differential amplifier, which has a power supply therefor separated from another power supply, is used as a direction-of-current detecting circuit that detects the direction of current from a voltage difference between two different power supplies. Consequently, a switch is logically turned on or off depending on whether charging or non-charging is under way. Thus, on voltage to be developed during charging is lowered. Moreover, the size or area of a transistor that acts as a logical circuit is made smaller than that of the backflow preventing diode. Furthermore, the energy of a storage cell included in the charging circuit is hardly consumed in any states.

Charging circuit

A crystal oscillator circuit using CMOSFETs including an oscillator circuit that is constructed of a resonating section and an amplifying section having a CMOSFET, a reference current source circuit for generating a reference current which determines a bias current of the amplifying section, and a control signal generator circuit for controlling the reference current source circuit to make a bias current larger than that in the oscillation status when the oscillator circuit is in the non-oscillation status. As a result, the reference current source circuit constant-current biases the DC bias of the amplifying section without depending on the source voltage. Therefore, it can lower the driving source voltage of the oscillator circuit. Further, only the bias current of the amplifying section is increased during the oscillation starting period of the oscillator circuit, so that the oscillator circuit can provide a stable oscillation with low power, without variations in the source voltage.

Crystal oscillator circuit using CMOSFETs

A gate oxide film is formed on a thin-film SOI substrate or on a single crystalline silicon substrate and a gate is formed on the gate oxide film. The surfaces of a single crystalline silicon at diffusion layer regions on opposite sides of the gate are cleaned and an amorphous silicon film is formed thereon and on the side walls of the gate. Impurity ions are implanted in the amorphous silicon film, which is then converted into recrystallized silicon films by annealing. An interlayer insulator film is formed and another annealing is conducted. As a result, impurity ions in the recrystallized silicon films diffuse into the diffusion layer region of the single crystalline silicon and are activated to form a source and a drain.

Semiconductor device having recrystallized source/drain regions

Semiconductor device and method of fabricating the same

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Kawagoe, Japan

Katsuyoshi Aihara