Patents Assigned to Seiko Epson Corp.
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Patent number: 5404322Abstract: A digital filter is designed by characterizing a desired filter passband in the frequency domain, transforming this representation into the time domain, selecting weighting coefficients at periodically spaced intervals from this transformed function, and weighting the coefficients with a Gaussian windowing function. This function may take the form:.sub.e -.vertline.( 2 n-N)/A.vertline..sup.Pwhere:A=N(-ln.epsilon.).sup.-1/P; .epsilon.<1.epsilon.=Window value desired at n= 0 and n=N (reduction ratio);N=(number of F.I.R. taps)- 1; andP=an arbitrary power.Type: GrantFiled: March 27, 1992Date of Patent: April 4, 1995Assignees: Seiko Corp., Seiko Epson Corp.Inventor: Mark R. Gehring
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Patent number: 5394552Abstract: A docking system comprising a first detecting element 13 which detects combination states of a personal computer 2 and a station 1. A second detecting element 14 is provided which detects a separation of the personal computer 2 from the station 1. The docking system also includes a combination holding element for holding a combination state of the personal computer side connector 33 and the station side connector 12. Furthermore, the docking system includes a switching element 32 for switching the personal computer side electric power source 39 to the station side electric power source 18. A third detecting element 34 is provided which detects placement of the personal computer 2 on the station 1. A control unit is provided which has three functions. First, it cuts the personal computer side electric power source 39 after performing backup processing of an execution program under a first set of predetermined conditions.Type: GrantFiled: July 17, 1992Date of Patent: February 28, 1995Assignee: Seiko Epson Corp.Inventor: Hironao Shirota
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Patent number: 5376856Abstract: A piezoelectric/electrostrictive actuator including a ceramic substrate and piezoelectric/electrostrictive elements is disclosed. The ceramic substrate includes: a spacer plate having a plurality of windows formed in a row in the longitudinal direction of the spacer plate, and auxiliary windows formed adjacent to respective two outermost windows which are located at the opposite ends of the row of the plurality of windows, such that the auxiliary windows sandwich the row of the plurality of windows; and a closure plate superposed on one of opposite major surfaces of the spacer plate, so that the plurality of windows and the auxiliary windows of the spacer plate are closed by the closure plate to provide pressure chambers and enclosed spaces, respectively, within the substrate. The spacer plate and the closure plate are formed from respective ceramic green sheets which are laminated on each other and fired into an integral structure as the ceramic substrate.Type: GrantFiled: February 22, 1994Date of Patent: December 27, 1994Assignees: NGK Insulators, Ltd., Seiko Epson Corp.Inventors: Yukihisa Takeuchi, Hideo Masumori, Katsuyuki Takeuchi
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Patent number: 5337314Abstract: A radio paging network transmits non-paging data, such as facsimile images, to lap top computer receivers by formatting the data into a series of packets and interleaving these packets, on a space available basis, into the paging signal.Type: GrantFiled: November 23, 1992Date of Patent: August 9, 1994Assignees: Seiko Corp., Seiko Epson Corp.Inventors: Don G. Hoff, Lawrence H. Ragan
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Patent number: 5309153Abstract: A paging system using synchronized transmission protocol and pagers active during monitor intervals to receive data transmitted during corresponding message intervals is provided with adaptive on-off radio receiver control for reducing monitor interval duration to conserve battery power. The adaptive on-off control is a function of recent timing errors and thereby accounts for environmental conditions.Type: GrantFiled: March 13, 1991Date of Patent: May 3, 1994Assignees: Seiko Corp., Seiko Epson Corp.Inventors: Garold B. Gaskill, Daniel J. Park
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Patent number: 5306664Abstract: A bump electrode of an inexpensive and reliable semiconductor device is provided in which a remaining metal wire portion produced during bump electrode formation is eliminated. The remaining metal wire portion made in a bump electrode forming method for a semiconductor device using a wire bonding technique is pressed and reshaped from above with heat or ultrasonic waves so as to apply pressure and heat to the bump electrode by using a stamping tool.Type: GrantFiled: May 15, 1992Date of Patent: April 26, 1994Assignee: Seiko Epson Corp.Inventor: Seiichi Sakura
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Patent number: 5301358Abstract: A wristwatch paging receiver is provided with an antenna matching network that automatically retunes the network at the beginning of a listening interval. During the retuning operation, a control signal is applied to a variable tuning element in the matching network, such as a varactor diode, and is swept from a minimum value to a maximum value. This sweeping is desirably performed in discrete voltage steps that correspond to unit increments of varactor capacitance. A feedback signal from the receiver, such as an AGC signal, is monitored during this operation to note which varactor bias signal yields the maximum AGC signal. After the sweep is concluded, the apparatus applies to the varactor the bias voltage that yielded the maximum AGC signal during the sweeping operation. This bias voltage is maintained through the end of the listening interval. At the beginning of the next listening interval, the process may be repeated.Type: GrantFiled: August 3, 1992Date of Patent: April 5, 1994Assignees: Seiko Corp., Seiko Epson Corp.Inventors: Garold B. Gaskill, Larry H. Mukai
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Patent number: 5298860Abstract: A method of analyzing metal impurities in a surface oxide film of a semiconductor substrate enables a detection sensitivity of the order of 10.sup.11 atoms/cm.sup.2 in a simple technique. This method comprises measuring a quantity of oxide charge resulting from specified metal impurities existing in the surface oxide film formed on the surface of a semiconductor substrate, and using a predetermined correlation between the quantity of metal impurities and the quantity of oxide charge to determine the quantity of metal impurities in the surface oxide film from the measured quantity of oxide charge of the surface oxide film.Type: GrantFiled: November 25, 1991Date of Patent: March 29, 1994Assignee: Seiko Epson Corp.Inventor: Juri Kato
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Patent number: 5296093Abstract: The invention comprises an improvement in the process wherein a polysilicon layer, which is formed over a step on an integrated circuit structure and masked with a photoresist, is anisotropically etched to remove the exposed portions of the polysilicon layer leaving sidewall residues of a polymerized silicon/oxide-containing material adjacent the polysilicon lines. The improvement comprises treating the integrated circuit substrate with an aqueous ammonium-containing base/peroxide solution to remove the residues of polymerized silicon/oxide-containing material, without undercutting the remaining polysilicon.Type: GrantFiled: May 27, 1992Date of Patent: March 22, 1994Assignees: Applied Materials, Inc., Seiko Epson Corp.Inventors: Chester Szwejkowski, Ian S. Latchford, Isamu Namose, Kazumi Tsuchida
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Patent number: 5280501Abstract: Bit synchronization is achieved by identifying potential bit sample points and assigning corresponding weight values as a function of signal noise vulnerability. The greater the possibility of error due to signal noise, the smaller the assigned weight value. The bit sample points associated with the largest accumulated weight value are taken as the appropriate data sample points for extracting information from the data signal. For a duobinary signal, zero crossings are identified as potential bit sample points and assigned a weight value corresponding to signal slope thereat. The number of possible bit sample points associated with each actual bit sample point is limited to a finite set by phase locking the carrier signal to the data rate.Type: GrantFiled: October 9, 1990Date of Patent: January 18, 1994Assignees: Seko Corp., Seiko Epson Corp.Inventor: Jeffrey R. Owen
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Patent number: 5266945Abstract: A method for searching for a station carrying paging data without unduly draining the paging receiver battery. If a station to which the receiver is presently tuned becomes unreliable, the pager scans among channels listed in a local channel list. If no paging data is received on these channels, the scanning among the local list channels may optionally proceed for a further interval at a slower rate. After it appears that paging data will not be found on channels listed in the local list, the pager begins a full spectrum search at a slow rate until it again finds a channel carrying paging data. By this arrangement, battery power is expended at a rate roughly in accordance with the likelihood of finding a paging station.Type: GrantFiled: January 15, 1991Date of Patent: November 30, 1993Assignees: Seiko Corp., Seiko Epson Corp.Inventors: William H. Peek, Garold B. Gaskill
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Patent number: 5263194Abstract: A radio receiver for use with a time slot paging system which receives intermittent data includes a direct coupled zero IF receiver circuit with at least one automatic gain control (AGC) amplifier stage. DC offset errors are removed from the AGC amplifier stages by a timed zero adjustment circuit that is switched into the AGC circuit just prior to the receipt of data. The resulting zero IF circuit may be miniaturized in monolithic form making it ideal for use in a wristwatch sized pager.Type: GrantFiled: March 7, 1990Date of Patent: November 16, 1993Assignees: Seiko Corp., Seiko Epson Corp.Inventor: Lawrence H. Ragan
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Patent number: 5253481Abstract: The compressor activation control unit a rotation detecting means for detecting whether or not the motor is normally activated when the compressor is activated, a judging means for judging that the compressor interior is filled with a liquid refrigerant when the motor is not judged to be in the normal activating condition by the rotation detecting means, and a control means for step-driving the motor at a very slow-speed no more then one rotation per second through the driving circuit when the motor interior is judged to have been filled with the liquid refrigerant by the judging means.Type: GrantFiled: August 27, 1992Date of Patent: October 19, 1993Assignees: Zexel Corporation, Seiko Epson Corp.Inventors: Nobukazu Takagi, Osamu Takahashi, Akihito Uetake, Osamu Shinkawa
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Patent number: 5247289Abstract: A liquid crystal display device is provided with a storage capacitor relative to each pixel electrode, and a common electrode is electrically connected to the storage capacitors of adjacent pixel structures between pairs of adjacent scan lines comprising paired odd and even numbered scan lines. With the utilization of this common electrode structure comprising commonly connected capacitor lines, the number of common electrodes necessary for electrically connecting storage capacitors of the pixel structures can be reduced by one-half and the number of the source electrodes connecting portions of the TFTs can be reduced by one-half as compared with the conventional technique utilizing a single storage capacitor per pixel structure. Therefore, a high aperture ratio can be maintained in spite of a decrease in pixel pitch to form a more dense pixel array. The common electrode lines could alternatively be formed between pairs of adjacent signal lines rather than pairs of adjacent scan lines, i.e.Type: GrantFiled: December 14, 1990Date of Patent: September 21, 1993Assignee: Seiko Epson Corp.Inventor: Yojiro Matsueda
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Patent number: 5214795Abstract: An AFC switch circuit is controlled by an select input logic signal for providing a selected output signal to control the local oscillator in a miniature FM receiver. The output signal has a voltage equal to either an AFC signal voltage for AFC operation of the receiver, or a reference voltage for synthesized operation of the receiver. The AFC switch circuitry employs bipolar transistors in current mirror configurations to minimize voltage offset and to enhance isolation between the unselected input and the output while operating on a power supply voltage less than 3 volts.Type: GrantFiled: June 29, 1989Date of Patent: May 25, 1993Assignees: Seiko Corp., Seiko Epson Corp.Inventor: Richard R. Suter
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Patent number: 5207520Abstract: A device for PWM control of the printer carriage motor (1) which has a circuit (65) for generating a first PWM pulses of 100% duty ratio, a circuit for computing second PWM pulses (31, 37, 39, 15, 17, 53, 57, 59) according to the PI control method based on the difference between the motor current speed and the predetermined standard speed, and a circuit (121) for holding the optimum integrated value for controlling the motor current speed agree with the standard speed. Until the motor current speed reaches a predetermined transfer speed slightly lower than the standard speed, the carriage motor is accelerated with the maximum acceleration according to the first PWM pulses, when the transfer speed is reached, the optimum integrated value is set as the initial integrated value of the PI control, and thereafter the speed control is carried out according to the PI control method.Type: GrantFiled: July 19, 1991Date of Patent: May 4, 1993Assignee: Seiko Epson Corp.Inventor: Hirotomo Tanaka
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Patent number: 5208810Abstract: Data flow control is achieved by use of variable length flags delimiting information packets whereby longer flags result in less information flow and shorter flags result in greater information flow. A single channel carries message data as well as status and command data in information packets delimited by the variable length flags. The channel runs continuously such as to provide a constant flow of status and command data, yet includes flow control for preventing overflow and underflow of message data at the receiving end of the channel.Type: GrantFiled: October 10, 1990Date of Patent: May 4, 1993Assignees: Seiko Corp., Seiko Epson Corp.Inventor: Daniel J. Park
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Patent number: 5196288Abstract: An image forming method of imagewise exposing and heating a light-sensitive material is disclosed. The light-sensitive material comprises a support and a light-sensitive layer provided thereon. The light-sensitive layer contains silver halide, a reducing agent, an ethylenically unsaturated polymerizable compound, a color image forming substance and a base precursor. The silver halide, the reducing agent, the polymerizable compound, the color image forming substance and the base precursor are contained in microcapsules which are dispersed in the light-sensitive layer. According to the present invention, the support is made of a thin polymer film having a thickness of not more than 75 .mu.m. The light-sensitive material is heated from the side of the support for 0.1 to 5 seconds.Type: GrantFiled: September 9, 1991Date of Patent: March 23, 1993Assignees: Fuji Photo Film Co., Ltd., Seiko Epson Corp., Seiko Instruments, Inc.Inventor: Taku Nakamura
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Patent number: 5189413Abstract: A frequency agile data receiver checks are needed, according to a first protocol, among a plurality of channels to find a channel carrying data. A control activated by the user interrupts this first protocol and institutes a second protocol different than the first. Applied to a paging receiver, the first protocol may sequentially tune the receiver to a plurality of previously identified channels to locate a channel on which paging data is satisfactorily received. The second protocol may sequentially tune to all possible channels to locate such a channel. By this arrangement, a person who knowingly moves to a new locality (e.g., flies to another city) can instruct the paging receiver to abandon a previously identified list of candidate channels and to begin a spectrum-wide scan to locate a new satisfactory paging channels.Type: GrantFiled: March 12, 1991Date of Patent: February 23, 1993Assignees: Seiko Corp., Seiko Epson Corp.Inventors: Garold B. Gaskill, Daniel J. Park
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Patent number: 5189411Abstract: Real time synchronization of radio signal data is achieved by a feedback loop between a clearinghouse generating data and a radio station transmitting data. Transmission time is adjusted in response to detected timing errors by selectively inserting padding data between certain data packets to shift data packet position within a data stream transmitted at a predetermined transmission rate. Data flow control is achieved by use of variable length flags delimiting data packets whereby longer flags result in less data flow and shorter flags result in greater data flow.Type: GrantFiled: October 10, 1990Date of Patent: February 23, 1993Assignees: Seiko Corp., Seiko Epson Corp.Inventors: James K. Collar, Garold B. Gaskill, Daniel J. Park, Carl D. Shanks, Rick T. Wells