Patents by Inventor Shotaro Yokoyama

Shotaro Yokoyama has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6108435
    Abstract: A method of detecting a phase difference between a pair of images of an object which are formed on a pair of optical sensor arrays through different optical paths, with presence of flare in one of the images, is disclosed.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: August 22, 2000
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Kenichi Mori, Shotaro Yokoyama
  • Patent number: 5659360
    Abstract: An image data circuit compensates sensitivity differences in image detection between a pair of image sensors. The image sensors each include a plurality of charge storage type optical sensing elements. Correction data indicative of sensitivity difference between the image sensors is stored in permanent memory. A clock pulse generator circuit generates clock pulses for counting charge storage periods indicated by output signals from the optical sensing elements. A pair of counter circuits counts the clock pulses and outputs count values corrected with the correction data and corresponding to the charge storage periods. A pair of quantizing circuits converts the output signals to image data based on the corrected count values.
    Type: Grant
    Filed: February 9, 1995
    Date of Patent: August 19, 1997
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Kenichi Mori, Shotaro Yokoyama
  • Patent number: 5602944
    Abstract: An object detecting system for an optical instrument having a pair of image sensors which receive light from objects in the field of view through different optical paths, each image sensor producing a group of image data representing the images of the objects in the field of view. Subgroups are formed from the groups of image data, wherein each subgroup represents image data corresponding to a portion of the field of view, and pairs of subgroups are formed with each pair of subgroups including one subgroup formed from each group of image data and both subgroups in each pair representing the same portion of the field of view. Consecutive overlapping segments of image data from each subgroup in each pair of subgroups are tested for high correlation between corresponding segments of image data from the subgroups of each pair. Clusters of segments of image data with high correlation are distinguished and one of the distinguished clusters is selected on the basis of a predetermined set of criteria.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: February 11, 1997
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Shotaro Yokoyama, Takashi Nishibe
  • Patent number: 5509309
    Abstract: An acceleration measuring device consists of a sealed-off, diode vacuum tube which in turn contains a cold cathode and an anode positioned at opposing longitudinal end regions of the vacuum tube via an inter-electrode space C. An inert argon gas is sealed in the vacuum tube at the pressure of 1 mm Hg. Because the acceleration measuring device utilizes field effect electron emission phenomenon, i.e., quantum mechanical tunneling by the Schottky effect, from the cold cathode, one obtains electron-emission characteristics which are essentially temperature independent. The vacuum tube also includes one or more areas connected to the inter-electrode space, local density of the gas in which connected areas changes in response to acceleration experienced by the acceleration measuring device, whereby the density of the gas in the inter-electrode space is altered.
    Type: Grant
    Filed: November 30, 1994
    Date of Patent: April 23, 1996
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Shotaro Yokoyama, Akira Amano, Kazuo Matsuzaki
  • Patent number: 5488645
    Abstract: For correction of an error caused in a period of a clock signal for digitizing a plurality of time signals, e.g., from an image sensor, a clock signal generating device generates a reference signal Sr indicative of a reference time of time signals TS from an OR-date (20). The device counts a reference clock signal .phi. in a frequency divider (30) until the reference signal Sr is generated, and outputs a divided clock signal .phi..sub.n with frequency dividing ratio 1/N from the frequency divider (30). It then counts the signal .phi..sub.n and stores the count value as a reference value S in a reference value counter (40). The device outputs an output clock signal .phi..sub.o from an output counter (50) each time the signal .phi. received after generation of the signal Sr reaches a predetermined value. It accumulates in an accumulator (60) the count value of the frequency divider (30) at the time of generation of the signal Sr in response to the signal .phi..sub.
    Type: Grant
    Filed: March 10, 1995
    Date of Patent: January 30, 1996
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Kenichi Mori, Shotaro Yokoyama
  • Patent number: 5233180
    Abstract: A light sensor device which uses semiconductors, can assure linearity even with low light intensity, and has a fast response time provides a voltage output proportional to a photoelectric current obtained from the output of an operational amplifier by accumulating the photoelectric current from a photodiode using the operational amplifier and an integration capacitance connected in parallel to the operational amplifier.
    Type: Grant
    Filed: May 28, 1992
    Date of Patent: August 3, 1993
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Yoshio Tsuruta, Shotaro Yokoyama, Takashi Nishibe
  • Patent number: 5198660
    Abstract: An optical sensing circuit having a photodiode, a differential amplifying circuit, and a comparator. The differential amplifying circuit is provided with an integral capacity. Adjusting capacities are connected in parallel to or disconnected from the integral capacity. A composite capacitance of the integral capacity and the adjusting capacities is adjusted by a control circuit so that the composite capacitance increases with increase of light intensity. This makes it possible to improve sensitivity of the optical sensing circuit for the light intensity and to widen the dynamic range for light sensitivity.
    Type: Grant
    Filed: August 27, 1991
    Date of Patent: March 30, 1993
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Shotaro Yokoyama, Takashi Nishibe
  • Patent number: 4969113
    Abstract: A method and apparatus for measuring the output of the measurement signal output by an optical sensor, for determining the intensity of the lights incident on the sensors. A plurality of setting values corresponding in a functional relationship to a plurality of estimated light intensity values being stored, prior to the measurement, in a memory. An address specifying means for causing the memory to output one of the plurality of setting values prestored therein during the time the address is specified. A count means for counting clock pulses with a predetermined period during the time duration of the measurement signal. A detecting means for detecting a comparison between the count value of the clock pulses and the setting value prestored in the memory and then causing the address specifying means to specify a new address in the memory in response to the detection result.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: November 6, 1990
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Takashi Nishibe, Shotaro Yokoyama
  • Patent number: 4958362
    Abstract: A circuit for generating clock signals includes a reference clock signal generator and a 1/N frequency divider for generating 1/N frequency divided clock signals. An up-counter counts the 1/N frequency divided clock signals until the occurrence of a first event. A programmable counter receives both an inverted count result as an initial value from the up-counter and the reference clock signals and counts the reference clock signals up to a predetermined count. When the programmable counter reaches the predetermined count it outputs a carry signal and is reset back to the initial value. As the programmable counter again counts from the initial value to the predetermined count, it again outputs a carry signal. These plurality of carry signals can be counted to provide a count corresponding to the amount of time between the occurrence of plurality of events.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: September 18, 1990
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Takashi Nishibe, Shotaro Yokoyama
  • Patent number: 4956546
    Abstract: A method and apparatus for aligning image sensors with an optical system in an optical apparatus utilizing photosensors incorporated in the image sensors with high precision. The reference light beams are focused on the image sensors each having a specified photosensor for receiving a respective light beam. Signal outputs from the specified photosensors of the image sensors are measured. The position of the image sensors is adjusted relative to the position of the optical system in response to the measured signal outputs.
    Type: Grant
    Filed: July 7, 1989
    Date of Patent: September 11, 1990
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Takashi Nishibe, Shotaro Yokoyama
  • Patent number: 4916307
    Abstract: A light intensity detecting circuit using a charge storage type of optical sensor having a parallel capacitor eliminates the influence of the dark current of the optical sensor and/or the influence of the offset of the comparator included in the detecting circuit so that the accuracy of the light intensity detection is improved over that of the prior art. To eliminate the influence of the dark current of the optical sensor in an image sensor, there is provided an optically shielded mimic sensor having the same structure as that of the optical sensor including a corresponding parallel capacitor. In order to eliminate the influence of the offset of the comparator, there is provided a time constant circuit having a capacitor that may be composed partially of the parallel capacitor of the mimic sensor corresponding to the parallel capacitor of the optical sensor; with potential applying means for operating the time constant circuit.
    Type: Grant
    Filed: December 12, 1988
    Date of Patent: April 10, 1990
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Takashi Nishibe, Shotaro Yokoyama
  • Patent number: 4904855
    Abstract: A method and system for finding an exact focus of a taking lens of a single lens camera or the like. The method detects the relative position between two images on the basis of light intensity distribution of the images from a pair of light sensor arrays that receive the images through light paths separated from each other in space. The relative position depends on whether a taking lens of a camera is in front-focus condition or in back-focus condition. Partial image data consisting of n data respectively are sampled from the two image data as verification data. A number of combinations of the data are used to calculate evaluation values indicative of the level of correlation between the respective verification data. Correct focus exhibits the highest correlation. The method overcomes the problem that the combination having the highest correlation may not be correctly determined due to abnormal shape or envelope of the plotted distribution of the evaluation value.
    Type: Grant
    Filed: November 28, 1988
    Date of Patent: February 27, 1990
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Takashi Nishibe, Shotaro Yokoyama
  • Patent number: 4883951
    Abstract: In a focus detection system in which light from an object is incident on at least two photosensor arrays via an optical system to form two images on the photosensor arrays, the relative displacement between the two images is determined in order to detect whether the optical system is in focus or not. A correction term which is formed by f(i.sub.0 +2) and f(i.sub.0 +1) or f(i.sub.0 -2) and f(i.sub.0 -1) is added to f(i.sub.0-1)-f(i.sub.0) or f(i.sub.0 +1)-f(i.sub.0), so that the amount of image deviation between the two images is obtained. Here i.sub.0 is the value of i when a function f(i) is minimized, the function f(i) expressing the inconsistency between the two images, corresponding to an amount of relative displacement i.times.p between the two images obtained discretely. The symbol p represents the pitch of the at least two photosensor arrays.
    Type: Grant
    Filed: March 21, 1989
    Date of Patent: November 28, 1989
    Assignee: Fuji Electric Company Ltd.
    Inventors: Shotaro Yokoyama, Takashi Nishinbe
  • Patent number: 4847483
    Abstract: A device for measuring the intensity of light received by a photosensor comprises a photosensor for receiving light and producing a corresponding current and a circuit for integrating the current so that the intensity of the received light is indicated as the time required for the integration value of the integrating circuit to reach a predetermined value. If the intensity of the light is determined to be high at the start of the integration operation the integration value is set to the smaller of two predetermined values. If the intensity of the light is low, the integration value is set to a larger value.
    Type: Grant
    Filed: December 24, 1987
    Date of Patent: July 11, 1989
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Takashi Nishibe, Shotaro Yokoyama
  • Patent number: 4727559
    Abstract: A weighted event counting circuit comprises a cascade connection circuit composed of a plurality of frequency dividing circuit means and a plurality of coincidence detecting circuit means inserted between the frequency dividing circuit means, and input circuit means to supply digital data representing the occurrence of plural events to the coincidence detecting circuit means. The number of occurrence times of the plural events is counted and totalized with weighting.
    Type: Grant
    Filed: January 27, 1986
    Date of Patent: February 23, 1988
    Assignees: Fuji Electric Co., Ltd., Fuji Electric Corporate Research and Development Ltd., Konishiroku Photo Industry Co., Ltd.
    Inventors: Shotaro Yokoyama, Takashi Nishibe, Seiichi Isoguchi
  • Patent number: 4668084
    Abstract: A distance measuring equipment wherein two images of an object are received on photosensor arrays each, two image data rows indicating a luminous intensity distribution in the object are compared with each other, and a distance to the object is measured from a mutual shift rate of both the signal rows which is required for bringing both the signal rows into coincidence at high correlation. A presence of the shift rate whereat the both image data rows indicate a high correlation is detected when it is present plurally, a part of the plural shift rate including a shift rate corresponding to the highest correlation is stored and taken.
    Type: Grant
    Filed: July 26, 1984
    Date of Patent: May 26, 1987
    Assignees: Konishiroku Photo Industry Co., Ltd., Fuji Electric Company, Ltd., Fuji Electric Corporate Research and Development Ltd.
    Inventors: Kiziro Suzuki, Takashi Tsutsumi, Shotaro Yokoyama, Takashi Nishibe
  • Patent number: 4659205
    Abstract: Disclosed is an automatic focusing system for optical imaging equipment, such as a camera, which includes a relative image displacement detection system providing first and second digital quantities indicative of the direction in which the focus of the imaging system is to be altered to achieve focus and the magnitude of such alterations, respectively, and an image contrast detection system providing a third digital quantity indicative of the change in the contrast of an image formed by the imaging system as the focus thereof is altered. In addition, the apparatus includes a servomotor for altering the focus of the imaging system and a motor control circuit which receives the first, second and third digital quantities and provides motor control signals to the servomotor.
    Type: Grant
    Filed: April 8, 1983
    Date of Patent: April 21, 1987
    Assignees: Fuji Electric Corporate Research & Development Co. Ltd., Fuji Elec. Co. Ltd.
    Inventors: Shotaro Yokoyama, Takashi Nishibe
  • Patent number: 4652119
    Abstract: A range finder wherein the quantization of analog outputs from light receptor elements for converting an optical image into an electrical signal is accomplished by comparing the outputs from at least two of the light receptor elements in each group, by dividing the outputs into the following three cases: one output is greater than the other; both are equal; and one is smaller than the other.
    Type: Grant
    Filed: January 18, 1984
    Date of Patent: March 24, 1987
    Assignees: Konishiroku Photo Industry Co., Ltd., Fuji Electric Company Ltd., Fuji Electric Corporate Research and Development Ltd.
    Inventors: Kiziro Suzuki, Seiichi Isoguchi, Koji Watanabe, Shotaro Yokoyama, Takashi Nishibe
  • Patent number: 4640613
    Abstract: In the particular embodiments of the invention disclosed herein, an image data comparison circuit receives digital image signal trains from two light sensor arrays of a rangefinder and compares the signals in the signal trains while they are being shifted with respect to each other. In one embodiment a set of coincidence detectors compares each signal in one signal train with all of the signals in one segment of the other image train and the number of coincidence detections by each detector is accumulated as the signal trains are cycled through corresponding shift registers. Another embodiment includes coincidence detectors for comparing all of the signals in corresponding segments of the two signal trains simultaneously.
    Type: Grant
    Filed: May 31, 1984
    Date of Patent: February 3, 1987
    Assignees: Fuji Electric Corporate Research and Development, Ltd., Fuji Electric Company, Ltd.
    Inventors: Shotaro Yokoyama, Takashi Nishibe
  • Patent number: 4611910
    Abstract: A range finder wherein a photocurrent in a predetermined number of light receiving elements corresponding to images formed by a first and a second optical devices for receiving light reflected by an object through different light paths on a focal plane, arranged in first and second light receiving element trains is quantized with reference to the maximum photocurrent in the light receiving elements by a first and a second quantizing devices, and wherein the corelation between the first and second quantizing devices are used for determining the distance to be measured.
    Type: Grant
    Filed: May 4, 1984
    Date of Patent: September 16, 1986
    Assignees: Konishiroku Photo Industry Co., Ltd., Fuji Electric Company Ltd., Fuji Electric Corporate Research and Development Ltd.
    Inventors: Kiziro Suzuki, Takashi Tsutsumi, Shotaro Yokoyama, Takashi Nishibe