Seiko Clock Inc.

Hiroyuki Hashizume

Koji Baba

Shigeru Kohata

A timepiece movement comprises a first luminous element for emitting light, a second luminous element for emitting light, and a light-receiving element for receiving the light emitted by the first and second luminous elements. A second wheel has an aperture through which light from the first luminous element may pass and a reflecting portion. A first transmitting wheel transmits a rotational drive to the second wheel as a function of second time and has an aperture through which light from the first luminous element may pass and which is positioned to become aligned with the aperture of the second wheel. A rotational minute wheel has apertures disposed at equal angular intervals and through which light from the second luminous element may pass. A rotational hour wheel has apertures through which light from the second luminous element may pass. Each of the apertures of the hour wheel are positioned to become aligned with respective ones of the apertures of the minute wheel during rotation of the minute and hour wheels. A second transmitting wheel transmits a rotational drive to the minute wheel and the hour wheel as a function of minute time and hour time, respectively. The second transmitting wheel has a plurality of apertures disposed at equal angular intervals and through which light from the second luminous element may pass. The apertures of the minute wheel are positioned to become aligned with respective ones of the apertures of the second transmitting wheel during rotation thereof.

Timepiece movement

A timepiece movement comprises a light-emitting device for emitting light and a light-receiving device for receiving the light emitted from the light-emitting device. An hour wheel has a plurality of apertures through which light from the light-emitting device may pass. A minute wheel has an aperture through which light from the light-emitting device may pass, the aperture being positioned to become aligned with respective ones of the apertures of the hour wheel during rotation of the minute and hour wheels. Minute and hour wheel gear trains respectively rotate the minute wheel and the hour wheel as a function of minute and hour time.

A clock movement includes a circuit board, first and second motors, a minute wheel connected to the first motor by a first gear train and an hour wheel connected to the second motor by a second gear train. The first and second gear trains preferably extend in a first direction, and the first and second motors are respectively disposed on opposite sides of the first and second gear trains and extend in a second direction transverse to the first direction. A first detection device detects when the minute hand is in a predetermined reference position and a second detection device detects when the hour wheel is in a predetermined reference position. The first detection device includes a minute detection sensor mounted on the circuit board and having a first light-emitting device and a first light-receiving device. The second detection device includes an hour detection sensor mounted on the circuit board and having a second light-emitting device and a second light-receiving device. The clock movement has a simple construction and is easy to manufacture, is suited to mass-production and can be manufactured at low cost.

Growing community of inventors

Tokyo, Japan

Hiroyuki Hashizume