Patents Assigned to Citizen Watch Company Limited
-
Patent number: 4453834Abstract: An electronic timepiece having a quartz crystal oscillator circuit as a timebase signal source is provided with a temperature compensation system to compensate timebase signal frequency deviations with temperature, all components of the system being incorporated in the timepiece IC chip. The system is based on a temperature-sensitive voltage stabilizer circuit whose output voltage is current-converted to control the frequency of a temperature-insensitive oscillator circuit. Date generated on the basis of the latter oscillator frequency is applied to compensate the timebase signal frequency, by a capacitor switching technique.Type: GrantFiled: July 1, 1982Date of Patent: June 12, 1984Assignee: Citizen Watch Company LimitedInventors: Fuminori Suzuki, Makoto Yoshida, Shigeru Morokawa
-
Patent number: 4451743Abstract: A DC-to-DC voltage converter is disclosed for converting the voltage from a battery to provide a power supply voltage whose value can be equal to the battery voltage multiplied by or divided by a non-integral factor, e.g. 2/3. The converter operates on the principle of capacitor charge switching, and high conversion efficiency is achieved in operation at very low levels of supply current, such as are utilized in an electronic timepiece.Type: GrantFiled: December 9, 1981Date of Patent: May 29, 1984Assignee: Citizen Watch Company LimitedInventors: Fuminori Suzuki, Singo Ichikawa
-
Patent number: 4448549Abstract: 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.Type: GrantFiled: February 9, 1982Date of Patent: May 15, 1984Assignee: Citizen Watch Company LimitedInventors: Shingo Hashimoto, Mitsuo Sekine
-
Patent number: 4443116Abstract: An electronic timepiece is provided with a timebase signal source comprising a relatively low frequency quartz crystal oscillator circuit and with means for compensating the timebase signal frequency for the effects of temperature changes on the low frequency oscillator circuit, and further with means for comparing the timebase signal frequency with the frequency of a relatively high frequency quartz crystal oscillator circuit having high stability against aging changes, to thereby compensate for changes in the timebase frequency caused by aging of the low frequency quartz crystal vibrator, this comparison being carried out only within a specific narrow range of operating temperatures.Type: GrantFiled: January 6, 1982Date of Patent: April 17, 1984Assignee: Citizen Watch Company LimitedInventors: Makoto Yoshida, Shinichi Watanabe, Fuminori Suzuki
-
Patent number: 4443062Abstract: In a multi-layer display device such as a liquid crystal display, each of a plurality of sets of display elements is defined by a corresponding common electrode and a plurality of segment electrodes. Segment electrodes of sets of display elements which will not be activated simultaneously are connected together, with at least one of these sets being maintained in a deactivated state by means of a special drive signal applied to the corresponding common electrode. The level of time-sharing which must be utilized for driving the various common electrodes, for a given number of external connections to the segment electrodes, can thereby be reduced, or the overall number of connections made to the display device can be substantially reduced.Type: GrantFiled: September 16, 1980Date of Patent: April 17, 1984Assignee: Citizen Watch Company LimitedInventors: Seigo Togashi, Akira Tsuzuki, Hiro Fujita
-
Patent number: 4441826Abstract: An electronic timepiece having voltage regulation, temperature detection and battery voltage detection means provided on the same integrated circuit as is used for timekeeping circuitry, and having external terminals for stepwise weighted adjustment of timekeeping gain/loss.Type: GrantFiled: September 30, 1982Date of Patent: April 10, 1984Assignee: Citizen Watch Company LimitedInventors: Shigeru Morokawa, Keiichiro Koga
-
Patent number: 4437768Abstract: An improved structure is disclosed for the movement of an electronic quartz crystal controlled wristwatch of very small size, suitable for use as a ladies bracelet timepiece. The configuration of this structure is such that a relatively large capacity battery can be utilized, thereby ensuring satisfactory battery life, by positioning the battery such as to substantially cover the wheel train of the timepiece and by a special arrangement of shapes and positions for other components of the timepiece.Type: GrantFiled: April 7, 1981Date of Patent: March 20, 1984Assignee: Citizen Watch Company LimitedInventor: Kenji Miyasaka
-
Patent number: 4435046Abstract: A liquid crystal display cell of annular form is provided with a central aperture to accommodate an analog time display section having time indicating hands. The annular liquid crystal cell is characterized in that a plurality of common electrodes are provided on one substrate of the cell, to enable multiplexed drive of the display elements of the cell. Each of the plurality of common electrode comprises a plurality of separate common electrode portions which are electrically connected by connecting lead portions. Half of the connecting lead portions can be arranged to be outside the display area of the cell, thereby enabling the available display area to be maximized.Type: GrantFiled: April 6, 1981Date of Patent: March 6, 1984Assignee: Citizen Watch Company LimitedInventor: Katsuo Nishimura
-
Patent number: 4435086Abstract: A liquid crystal display device for a world time electronic timepiece in which a display of world time is made by a liquid crystal display device, with various locations on a world map being selectable for display of local time, a corresponding marker on the world map being caused to flash to indicate selection and the name of the selected location being displayed in abbreviated form simultaneously with the local time at the selected location.Type: GrantFiled: July 16, 1981Date of Patent: March 6, 1984Assignee: Citizen Watch Company LimitedInventor: Yoshiaki Kato
-
Patent number: 4433920Abstract: In an electronic timepiece having a primary frequency divider circuit coupled to receive a standard frequency signal and comprising a group of P-channel FETs and a group of N-channel FETs, a bias circuit supplies a bias input to the P-channel FET group and a separate bias input to the N-channel FET group. By providing these bias inputs through current mirror coupling from a standard current source, the response of the primary frequency divider circuit to low amplitudes of the standard frequency signal can be made substantially independent of timepiece battery voltage variations, over a wide range of battery voltages.Type: GrantFiled: July 7, 1981Date of Patent: February 28, 1984Assignee: Citizen Watch Company LimitedInventors: Fukuo Sekiya, Shigeru Morokawa, Ryoji Iwakura
-
Patent number: 4433918Abstract: An electronic timepiece of analog display type is provided with at least one other additional function mode such as an alarm mode in addition to a current time mode of operation. When changeover from one function mode to another is performed, by actuation of an external operating member, information indicated by the timepiece analog display is rapidly changed over to correspond to information for the new function mode, e.g. is rapidly changed over to indicate an alarm time when changeover from the current time mode to the alarm time mode is performed, and rapidly changed to indicate current time when the reverse mode changeover is performed.Type: GrantFiled: July 7, 1981Date of Patent: February 28, 1984Assignee: Citizen Watch Company LimitedInventors: Katsuo Nishimura, Fukuo Sekiya
-
Patent number: 4430648Abstract: A display device of solid-state matrix type, such as a liquid crystal display device, retains display data for an unlimited period after such data has been written into the display, with no need for periodic re-writing of the display data to compensate for deterioration due to leakage effects. In addition, the display data can be read out again, if required, so that the display device can also be used as a memory. such a display device can also be utilized to perform data input, by writing in of data through application of light to the display surface, such as by using a light pen.Type: GrantFiled: January 12, 1981Date of Patent: February 7, 1984Assignee: Citizen Watch Company LimitedInventors: Seigo Togashi, Akira Tsuzuki
-
Patent number: 4427302Abstract: A timekeeping signal source for an electronic timepiece produces a highly accurate timekeeping signal which is stable in frequency with respect to both temperature variations and long-term drift. The timekeeping signal is produced by phase lock control using a high frequency reference signal from a crystal-controlled high-frequency oscillator. Phase lock control can be performed continuously or on an intermittent basis, in order to reduce power consumption. In addition, the timekeeping rate can be adjusted with a resolution within one period of the high frequency reference signal, by variation of a numeric value stored in digital memory means.Type: GrantFiled: June 1, 1981Date of Patent: January 24, 1984Assignee: Citizen Watch Company LimitedInventor: Shinichi Watanabe
-
Patent number: 4423963Abstract: An electronic timepiece is provided with a photo-electric cell generating an output voltage indicative of incident illumination levels, circuit means for converting this output voltage into digital data signals, and a liquid crystal display which is driven in response to the data signals such that successive sections of the display act to progressively unmask a rear reflector plate to thereby indicate the illumination level. The circuits for converting illumination level to data signals are based on an oscillator circuit whose frequency is controlled by the photo-electric cell voltage, and digital means for measuring this frequency, so that the circuit configuration is very simple and power comsumption extremely low.Type: GrantFiled: September 15, 1982Date of Patent: January 3, 1984Assignee: Citizen Watch Company LimitedInventor: Fuminori Suzuki
-
Patent number: 4423686Abstract: A table apparatus provided with a stacked array of upper and lower slides which are driven independently of each other, in which at least one slide surface of the lower slide is a slide guide shaft which is reciprocatively rotatable and which has a non-circular cross-section, and in which there are provided a rotation transmission mechanism disposed on the table of the lower slide and engaging with the slide guide shaft, said transmission mechanism being slidable axially of the slide guide shaft and rotatable along with said slide guide shaft, and an upper slide drive mechanism for sliding the upper slide in response to the rotation of said rotation transmission mechanism.Type: GrantFiled: December 23, 1981Date of Patent: January 3, 1984Assignee: Citizen Watch Company LimitedInventors: Katumi Ueno, Genichi Nishizaki
-
Patent number: 4419019Abstract: An analog display type of electronic timepiece is provided with an alarm function, whereby changeover can be rapidly performed between display of current time and of a preset alarm time, by rapid rotation of the timepiece hands, and features means whereby the hands are advanced in steps of less than one minute during the current time display state but are advanced by steps of precisely one minute while setting of an alarm time is being carried out, so that the alarm time is precisely set with the minutes hand positioned at a minutes graduation on the dial.Type: GrantFiled: April 14, 1982Date of Patent: December 6, 1983Assignee: Citizen Watch Company LimitedInventors: Katsuo Nishimura, Minoru Watanabe
-
Patent number: 4417113Abstract: In a push-button device having a waterproofing O-ring disposed between the inner wall of a pipe and the shaft portion of a button body, the structure of said push-button device characterized in that a non-metallic, resilient sleeve for preventing the invasion of dust and for restoring the push-button is disposed in a clearance formed between the head portion of the button body and a stepped portion provided on said inner wall of said pipe.Type: GrantFiled: February 5, 1981Date of Patent: November 22, 1983Assignee: Citizen Watch Company LimitedInventors: Motoyuki Saito, Satoru Fukutome
-
Patent number: 4413539Abstract: In a numerically controlled lathe, two guide bars are located in front of a headstock and extending parallel to the axis of a spindle to guide a saddle theroen. A cross slide is slidably supported by a guideway of the saddle to move a pair of turret heads in a direction perpendicular to the axis of the spindle. Turret indexing means allows indexing of one of the turret heads while a tool receiver fixed on the other turret head assumes in a predetermined cutting area relaive to the axis of the spindle. The saddle has a chip dropping wall formed between a guide bush and the pair of turret heads, with a front portion of the chip dropping wall downwardly slanting toward the front side of the lathe.Type: GrantFiled: October 29, 1980Date of Patent: November 8, 1983Assignee: Citizen Watch Company LimitedInventors: Shinichi Ishizuka, Kenji Sugimoto
-
Patent number: 4408900Abstract: A joint structure of a watch body and a bezel comprising a watch body with a joint surface, a bezel with a joint surface, at least one projection extending from one of the joint surfaces welded onto the other surface, a space between said surfaces and connecting material filling said space. By thus constructing, the watch body and bezel have a durable water and air tight joint.Type: GrantFiled: April 17, 1981Date of Patent: October 11, 1983Assignee: Citizen Watch Company LimitedInventors: Tsuneji Takasugi, Seiji Umezawa
-
Patent number: 4404067Abstract: A method of manufacturing components of a timepiece dial, such as timekeeping hands and dial plates, whereby these components can be made extremely thin, while warping is held to a very low level even if the component is subjected to machining operations. The method is based upon utilizing a plurality of electroformed metal layers having different types of internal stress, i.e.Type: GrantFiled: March 16, 1982Date of Patent: September 13, 1983Assignee: Citizen Watch Company LimitedInventor: Tadao Enomoto