Noise Reduction Or Elimination Patents (Class 348/683)
  • Patent number: 9300204
    Abstract: A switching power supply comprises a noise detecting circuit and a canceling signal generating circuit. The noise detecting circuit detects GND bounce noise developing on a ground line of the control circuit accompanying switching operation of a switching element. The canceling signal generating circuit generates a canceling signal corresponding to the GND bounce noise and in a reversed phase, and adds the canceling signal to the ground line when the noise detecting circuit detects the GND bounce noise. In an embodiment, the canceling signal generating circuit generates a canceling signal based on the current flowing through the switching element. In another embodiment, the canceling signal generating circuit generates a canceling signal of a pulse signal with a pulse height equal to a threshold level for detection determination of the GND bounce noise in the noise detecting circuit.
    Type: Grant
    Filed: August 8, 2013
    Date of Patent: March 29, 2016
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventor: Kenichi Nishijima
  • Patent number: 9024961
    Abstract: A method for color grading input video data for display on a target display comprises obtaining target display metadata indicative of a capability of the target display, obtaining input video data metadata indicative of image characteristics of the input video data, automatically determining initial values for parameters of a parameterized sigmoidal transfer function, at least one of the initial values based at least in part on at least one of the target display metadata and the input video data metadata and mapping the input video data to color-graded video data according to the parameterized transfer function specified using the initial values.
    Type: Grant
    Filed: December 18, 2012
    Date of Patent: May 5, 2015
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Peter W. Longhurst, Neil W. Messmer, Steve Margerm, Robin Atkins
  • Patent number: 8963945
    Abstract: A red, green, and blue (RGB) primary generation system and method for a wide color gamut, and a color encoding system using the RGB primaries. The RGB primary generation system may achieve a wide color gamut by generating a color gamut having a gamut coverage which meets a gamut coverage threshold, meeting a unique hue, having a maximum gamut efficiency, and a minimum quantization error.
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: February 24, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Yun-Tae Kim, Seo Young Choi, Ho Young Lee, Du-Sik Park, Ji Young Hong
  • Patent number: 8907973
    Abstract: An image processor includes generates a content adaptive kernel from an image block with noise of a luminance component signal with a low resolution. The content adaptive kernel is convolved with the luminance component signal. A noise signal and an extracted texture which excludes noise are generated. The luminance component signal is filtered as function of the noise signal to generate an enhanced luminance component signal. Horizontal and vertical scaling is performed on the enhanced luminance component signal, the extracted texture, and the luminance component signal, with the luminance component signal adaptively scaled as a function of the extracted texture. The horizontally and vertically scaled enhanced luminance component signal, extracted texture and luminance component signal are then combined to generate an output luminance component signal with a high resolution.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: December 9, 2014
    Assignee: STMicroelectronics International N.V.
    Inventor: Chandranath Manchi
  • Publication number: 20140313417
    Abstract: An information processing apparatus includes a processor that receives captured image data and captured sound data corresponding to an environment in which content is reproduced and detects a user based on the captured image data and analyzes a situation of the environment based on a result of the detection and the captured sound data and controls an audio volume corresponding to reproduced content based on a result of the analyzing.
    Type: Application
    Filed: July 19, 2012
    Publication date: October 23, 2014
    Applicant: SONY CORPORATION
    Inventor: Kazuya Tateishi
  • Patent number: 8854550
    Abstract: A data processing device includes a clock converter, a data converter, and an error detector. The clock converter is configured to receive a first clock signal, convert the first clock signal into a second clock signal, and output the second clock signal. The data converter is configured to receive first data, convert the first data into second data using the second clock signal, and output the second data. The error detector is configured to check whether the first clock signal is in a first clock state or a second clock state upon the first data transitioning to a first data state, and output an enable signal to the clock converter upon determining that the first clock signal has transitioned to the first clock state from the second clock state.
    Type: Grant
    Filed: November 4, 2013
    Date of Patent: October 7, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tae-Pyeong Kim, Han-Kyul Lim, Cheon-Oh Lee
  • Patent number: 8610800
    Abstract: An image processing device is comprised of: a frequency component resolution section for resolving an image obtained from an image sensor having a light-shielded pixel area and a non-light-shielded pixel area into two or more frequency components; a noise amount calculation section for calculating a noise amount for the frequency component based on the frequency component in the light-shielded pixel area; a noise suppression section for suppressing the noise component for the frequency component in the non-light-shielded pixel area according to the noise amount that has been calculated by the noise amount calculation section; and a frequency component synthesis section for synthesizing the frequency component that has been resolved by the frequency component resolution section to thereby form an image.
    Type: Grant
    Filed: August 7, 2009
    Date of Patent: December 17, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hideki Ikedo
  • Patent number: 8549577
    Abstract: Example frequency agile band-pass filtering methods disclosed herein include monitoring reception quality of a media broadcast signal received at a headend including a frequency agile band-pass filter to receive the media broadcast signal, sending a first set of commands to cause the frequency agile band-pass filter to tune to and attenuate a first channel included in the media broadcast signal, the first set of commands being sent in response to determining that the first channel is experiencing a degradation of reception quality determined to be caused by a first type of channel interference, and sending subsequent second set of commands over the communication network to the frequency agile band-pass filter to override attenuation processing invoked by the first set of commands in response to determining that the degradation of reception quality is caused by fading in addition to the first type of channel interference.
    Type: Grant
    Filed: January 16, 2013
    Date of Patent: October 1, 2013
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Brian Wilson, Frank Robert Coppa, Douglas Medina
  • Patent number: 8532222
    Abstract: A digital broadcast transmitter includes a block processor encoding mobile service data at a coding rate of 1/H and first interleaving the encoded mobile service data, wherein H is an integer equal to or greater than 2, a deinterleaver deinterleaving the first-interleaved mobile service data to output a first data group, an interleaver second interleaving the first data group to output a second data group including the mobile service data, a trellis encoding module trellis encoding data of the second data group, and a multiplexer multiplexing the trellis-encoded data with segment synchronization data and field synchronization data, wherein the block processor is concatenated with the trellis encoding module.
    Type: Grant
    Filed: April 9, 2012
    Date of Patent: September 10, 2013
    Assignee: LG Electronics Inc.
    Inventors: Byoung Gill Kim, In Hwan Choi, Jin Woo Kim, Jong Moon Kim, Won Gyu Song, Hyoung Gon Lee, Kook Yeon Kwak
  • Patent number: 8503820
    Abstract: Provided are a method and apparatus for removing image noise. The method includes: separating an input image signal into a signal component and a noise component; converting the noise component into a decorrelated noise component that is spatiotemporally decorrelated from neighboring pixels; and generating an image signal by adding the decorrelated noise component to the signal component.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: August 6, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Mi-yeon Lee, Seung-hoon Han
  • Patent number: 8482577
    Abstract: Disclosed herein are a method for controlling the output of a display unit to meet various requirements of the user, and an output control apparatus employing the same.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: July 9, 2013
    Assignee: LG Electronics Inc.
    Inventors: Hong Su Kim, In Hoon Kim
  • Patent number: 8370890
    Abstract: Methods and apparatus for frequency agile band-pass filtering of broadcast signals are disclosed. An example method to receive a broadcast signal for distribution to a plurality of reception sites disclosed herein comprises processing the broadcast signal with a frequency agile band-pass filter to receive the broadcast signal at a headend site for distribution to the plurality of reception sites, monitoring reception quality of the broadcast signal at an operating center separate from the headend site and included in the plurality of reception sites, and sending commands to the frequency agile band-pass filter from the operating center based on the monitored reception quality of the broadcast signal, the commands controlling at least a tuned operating frequency of and an attenuation provided by the frequency agile band-pass filter.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: February 5, 2013
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Brian Wilson, Douglas Medina, Frank Coppa
  • Patent number: 8305397
    Abstract: A noise removing filter removes noise from an input image and an edge component extracting unit extracts edge components. The edge components are extracted by calculating a difference between the input image and a smoothed image, which is obtained by smoothing the input image in a smoothed image generating portion. An edge component comparing unit compares the extracted edge components with a threshold value and a sum calculating unit calculates the sum of the edge components greater than the threshold value. A control circuit determines the enhancement degree of the edges based on the sum and averaged luminance of the input image calculated by an average luminance calculating unit. An enhancement degree adjustment unit adjusts the determined enhancement degree, and an edge component enhancement unit enhances the edge components based on this enhancement degree and adds it to the input image to perform edge enhancement processing.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: November 6, 2012
    Assignee: Eizo Nanao Corporation
    Inventors: Koichi Ueno, Masanori Katsura, Kazuyuki Watanabe, Yasuhiro Kobayashi, Kiyoyuki Tanaka
  • Patent number: 8300150
    Abstract: An image processing apparatus includes a pixel difference calculator, a summing unit, a determining unit, and an output unit. The pixel difference calculator receives a present image having first pixels and a previous image having second pixels, calculates pixel differences between corresponding first and second pixels, and outputs positive and negative pixel difference values. The summing unit obtains a first output value by adding up those of the positive pixel difference values and a second output value by adding up those of the negative pixel difference values. The determining unit determines a noise level of the present image from the first and second output values, and outputs a blended value. The output unit adds together weights of pixels at the same positions of the present and previous images according to the blended value to generate an output image. An image processing method is also disclosed.
    Type: Grant
    Filed: October 5, 2009
    Date of Patent: October 30, 2012
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chien-Chen Chen, Chun-Hsing Hsieh
  • Patent number: 8189107
    Abstract: A system, method and computer program product are provided. After receipt of visual data, an aspect of the frequency response associated with the visual data is changed. Thereafter, subsequent processing is performed on the visual data, based on information extracted from and related to the aspect of the frequency response change.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: May 29, 2012
    Assignee: NVIDIA Corporation
    Inventor: William S. Herz
  • Patent number: 8181216
    Abstract: A data processing apparatus that appropriately adjusts the image quality of an image. At a plurality of user terminals, image data transmitted from a broadcasting station is processed based on parameters input by users, and user information including the image data and the parameters is provided to a management server. The management server calculates noise amounts of the respective sets of image data included in the user information provided from the plurality of user terminals, calculates an average value of parameters input by users for each noise amount, and associates the average value with the noise amount. Furthermore, the management server provides a user terminal with server information including a parameter associated with a noise amount of image data from a user terminal. The user terminal processes the image data based on the parameter included in the server information from the management server.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: May 15, 2012
    Assignee: Sony Corporation
    Inventors: Tetsujiro Kondo, Kazutaka Ando
  • Patent number: 8106970
    Abstract: An estimated noise shape estimated to be included in the signal to be corrected is calculated based on a calibration signal including a noise correlating with the noise of the signal to be corrected so as to correct a noise of a signal to be corrected. A correction value of a noise shape is generated by attenuating an amplitude of the estimated noise shape, and the noise of the signal to be corrected is corrected by using the correction value of the noise shape thus generated.
    Type: Grant
    Filed: August 25, 2008
    Date of Patent: January 31, 2012
    Assignee: Nikon Corporation
    Inventor: Akihiko Utsugi
  • Patent number: 8090018
    Abstract: The invention discloses an image processing apparatus for improving the definition of an input image. The input image consists of a plurality of pixels, and the pixels are divided into an edge portion and a background portion. The image processing apparatus includes a compound operating unit, a sharpness processing unit, and an edge detecting unit. The compound operating unit is used for generating a noise-eliminated image by subjecting the input image to an open-close process and a close-open process. The sharpness processing unit is used for generating an enhanced image by subjecting the input image to a sharpness process. The edge detecting unit is used for receiving the noise-eliminated image and the enhanced image and determining whether each pixel of the input image belongs to the edge portion or the background portion, so as to selectively output the gray level of each pixel of the enhanced or noise-eliminated image.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: January 3, 2012
    Assignee: Quanta Computer Inc.
    Inventors: Tung-Lin Hsieh, Yu-Wen Huang, Ming-Horng Shiu, Hsin-Hung Lee
  • Patent number: 7800629
    Abstract: Provided is an image processing apparatus and method for preventing degradation of image quality occurring when a bit-format of an image is converted. When a raw image is converted to an image having specific color resolution, the image to be converted can maintain an image close to the raw image by obtaining errors between pixels of the raw image and the image to be converted and minimizing the errors between the raw image and the image to be converted using an error diffusion scheme.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: September 21, 2010
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Seung-Cheol Lee, Sang-Bong Lee, Joon-Kyu Moon
  • Patent number: 7756498
    Abstract: Disclosed is a channel estimator and a method for changing a coefficient of an IIR filter depending on a moving speed of a mobile communication terminal. In the channel estimator, a coefficient changing unit receives I and Q signals from a current base station, and selects a coefficient of the IIR filter optimized depending on the moving speed of the current mobile communication terminal. The coefficient changing unit sets the selected coefficient of the IIR filter to the IIR filter of the channel estimator. Accordingly, it is possible to prevent the performance degradation of the channel estimator caused by the speed of the mobile communication terminal.
    Type: Grant
    Filed: August 6, 2007
    Date of Patent: July 13, 2010
    Assignee: Samsung Electronics Co., Ltd
    Inventor: Soo-Jin Park
  • Patent number: 7660483
    Abstract: One embodiment of the present invention provides a system that removes noise from an image. During operation, the system first identifies blobs in the image, wherein a blob is a set of contiguous pixels which possibly represents a character or a portion of a character in the image. Next, the system analyzes the blobs to dynamically determine a “noise threshold” for the blobs. The system then removes blobs from the image which are below the noise threshold.
    Type: Grant
    Filed: November 30, 2005
    Date of Patent: February 9, 2010
    Assignee: Adobe Systems, Incorporated
    Inventor: Dennis G. Nicholson
  • Patent number: 7474316
    Abstract: A dithering pattern that is generated based on a spatial operation is used for a Bit-Depth Extension (BDE) technique for preventing contouring artifacts in an image displayed by a display having a bit-depth that-is less than the bit-depth of the image. The dithering pattern can be based on achromatic visual model or a spatio-chromatic visual model. The dither pattern is formed by shaping a pseudo-random noise signal by an equivalent noise visual model that is based on an array of pixels. Alternatively, the array of pixels is based on an image, or a determinate array of pixels.
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: January 6, 2009
    Assignee: Sharp Laboratories of America, Inc.
    Inventor: Scott J. Daly
  • Patent number: 7376210
    Abstract: Disclosed is an adaptive channel estimator for improving a performance of a general channel estimator in a mobile communication system, and a method for controlling the same. The adaptive channel estimator further detects a noise level of a channel and a channel speed, and implements an optimum noise elimination filter on the basis of the detected noise level and channel speed. A comparison between mapping degrees predetermined by the detected noise level and channel speed allows an optimum noise elimination filter to be implemented, If such a channel estimator is implemented, then optimum packet data transmission is available for not only a low-speed channel but also a high-speed channel. A channel compensation caused by a difference between a spreading factor (SF) of a pilot channel and a spreading factor (SF) of a data channel can be compensated on the condition that a slope compensator executed by a SF ratio is controlled by a filter coefficient controller.
    Type: Grant
    Filed: July 8, 2003
    Date of Patent: May 20, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hun-Kee Kim, Gin-Kyu Chol, Yong-Suk Moon, Noh-Sun Kim
  • Patent number: 7324078
    Abstract: A display apparatus including an offset value setting input part to specify an offset value for a DE signal determining an effective area of a video signal; and a DE signal generator to generate the DE signal depending on the offset value. With this configuration, the present invention provides a display apparatus and a control method thereof, which in advance, offsets a noise section contained in a video signal.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: January 29, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Young-chan Kim
  • Patent number: 7110042
    Abstract: The invention relates to a synchronization signal decoder and associated method for improving digital image display. A composite video stream includes a distortion compliant signal and a synchronization signal. A level shift circuit is adapted to shift a voltage level of the composite video stream such that the distortion compliant signal is readily distinguishable from the synchronization signal. A level shift disable circuit is adapted to disable the level shift circuit responsive to the composite video stream.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: September 19, 2006
    Assignee: Pixelworks, Inc.
    Inventor: William C. Bradley
  • Patent number: 7106386
    Abstract: A picture quality improvement device has two-dimensional low-pass filter that takes as input a luminance signal YIN that is obtained from a video signal and that extracts low-pass components for a vertical direction and a horizontal direction of the input luminance signal YIN. The picture quality improvement device adds an edge signal, which is obtained by subtracting from luminance signal YIN the low-pass extraction signal (LPF) that has been extracted by two-dimensional low-pass filter, to luminance signal YIN. Two-dimensional low-pass filter is constituted such that the extraction gain of the vertical direction low-pass component and the extraction gain of the horizontal direction low-pass component are independently adjusted.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: September 12, 2006
    Assignee: NEC Viewtechnology, Ltd.
    Inventor: Michio Kobayashi
  • Patent number: 7043093
    Abstract: At first, average brightness of each of frames of a moving image is calculated by a computer. Following that, a moving average along a time axis is calculated for each of the frames so that moving average brightness is generated as a reference data of brightness. Next, difference data between the average brightness and the moving average brightness are generated. Further, the difference data are grouped based on the signs of the reference data. Then, on the basis of the grouped difference data, it is judged whether an unwanted change of brightness is present. Thus, it is automatically and precisely judged whether the unwanted change of brightness such as a flicker is present in the moving image.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: May 9, 2006
    Assignee: Minolta Co., Ltd.
    Inventor: Motohiro Asano
  • Patent number: 6968154
    Abstract: The invention relates to the simultaneous operation of items of electrical apparatus, such as but not exclusively, a broadcast data receiver and a DECT telephone system. A problem with this type of apparatus is that the operating frequencies of the same can overlap and in turn cause interference in the operation of the respective items. The invention provides a method for identifying the overlap of the RF ranges of the apparatus, and having identified the same, adjusting the operating characteristics of one of the items to allow the interference to be avoided or minimized and the opportunity for the items of apparatus to be combined into one unit.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: November 22, 2005
    Assignee: Pace Micro Technology Plc
    Inventors: Stephen Beales, Stuart Griffin
  • Publication number: 20040172659
    Abstract: An arrangement for the reduction of noise transmitted in the return direction fron a local cable TV network (10) comprises an input (14), an output (16), means (21) for evaluating signals incoming at the input (14), and blocking means (17) controllable by said evaluation means (21). Said blocking means are formed by a reprogrammable digital signal processing unit (17), which is connected to the input (14) via an analog-to-digital converter (19) and which is arranged to generate digital output signals corresponding to portions of the incoming signals, depending upon the existing programming of the signal processing unit (17) and the result of the evaluation of the incoming signals effected by the evaluation means (21), and to deliver said digital output signals to a digital-to-analog converter (24) connected to the output (16).
    Type: Application
    Filed: January 12, 2004
    Publication date: September 2, 2004
    Inventors: Kjell Arne Ljungdahl, Bo Peter Cullblom, Lars A. P. Carlsson
  • Patent number: 6714258
    Abstract: A video apparatus includes a circuit for reducing noise in applied input video signals. The noise reducing circuit is provided with a temporal noise filter (S1, LUT, M), a down-sample unit (D) for obtaining a spatial down-sampling of video signals (Vi) of subsequent pixels, these down-sampled video signals being supplied to the temporal noise filter (S1, LUT, M), and an up-sample unit (U) for generating, in response to noise output signals obtained in the temporal noise filter (S1, LUT, M), noise signals of the pixels, and a subtractor (S2) for subtracting the noise signals from the respective input video signals (Vi).
    Type: Grant
    Filed: March 14, 2001
    Date of Patent: March 30, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Jeroen Hubert Christoffel Jacobus Stessen, Gerard De Haan, Robert Jan Schutten, Fransiscus Wilhelmus Sijstermans
  • Patent number: 6542202
    Abstract: A video signal processing apparatus capable of improving signal level while reducing noise component no matter a video signal of what illuminance is input is provided, which apparatus includes a video signal amplifying circuit amplifying an input video signal and outputting a video signal of a predetermined image size in accordance with a gain control coefficient, a frame addition circuit connected to the video signal amplifying circuit for adding outputs of the video signal amplifying circuit by a predetermined number of frames, a first signal level detecting circuit connected to the video signal amplifying circuit and calculating the gain control coefficient and a multiplication coefficient in accordance with an output of the video signal amplifying circuit, and a first multiplier connected to the frame addition circuit and the first signal level detecting circuit and receiving as inputs an output of the frame addition circuit and the multiplication coefficient.
    Type: Grant
    Filed: August 17, 1999
    Date of Patent: April 1, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Mitsuhiko Takeda, Mamoru Oda
  • Patent number: 6512339
    Abstract: In a CRT display device including a CRT (MM tube) having brightness higher than that in the background-art CRT, it is an object of the present invention to improve contrast and prevent conspicuous recognition of noises. A video signal modulation circuit (10) modulates a video signal (9) (first video signal) into a second video signal having a signal level in an area of low gradation level lower than a signal level of the first video signal. A cathode bias voltage source (7) generates a driving voltage on the basis of the second video signal. It is therefore possible to keep the driving voltage in the area of low gradation level low and reduce brightness in the area of low gradation level of a CRT (1). As a result, noises of an image in the area of low gradation level are not conspicuously recognized and a contrast value is increased, resulting in improvement in image quality.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: January 28, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshitomo Nakamura, Haruo Shigematsu, Akinori Heishi, Hironobu Yasui
  • Publication number: 20020093595
    Abstract: A detection circuit detects a slice start code from an input stream. Based on a result of the detection and a frame pulse, a reference macroblock (MB) address generated by a timing generator is sent to an address comparator. The input stream which has been phase-adjusted by a delay circuit is supplied to a variable length decoder (VLD) for decoding a variable length code to detect an MB address. The address comparator compares the reference MB address with the MB address to check the continuity of the MB address. If it is discontinuous, the stream output from the VLD is temporarily interrupted, and a selector selects a replacement data generating circuit in response to a control signal output from the address comparator. The input stream is replaced at a discontinuous macroblock portion with macroblock data which has a correct macroblock address and which is prepared in advance by the replacement data generating circuit.
    Type: Application
    Filed: December 27, 2001
    Publication date: July 18, 2002
    Inventors: Akira Sugiyama, Haruo Togashi, Shin Todo, Hideyuki Matsumoto
  • Patent number: 5986719
    Abstract: A video clamping apparatus is described which uses transistors manufactured in a CMOS process to clamp an input video signal to a reference level during a SYNC period. A closed-loop system is provided which includes a buffer amplifier, a sample-and-hold device, a summer, a low-pass filter and a clamping circuit. The summer compares the output of the sample-and-hold device to a reference voltage which causes an output of an analog-to-digital converter to be the digital word zero.In order to maintain a high enough bandwidth of the closed loop system, a first current source is operatively coupled to the transistors of the clamping circuit during the SYNC period. When the SYNC period has ended, the first current source is decoupled from the transistors of the clamping circuit. The transconductance of the loop is, therefore, high when needed during the SYNC period.
    Type: Grant
    Filed: May 28, 1996
    Date of Patent: November 16, 1999
    Assignee: Analog Devices, Inc.
    Inventor: Katsufumi Nakamura
  • Patent number: 5841563
    Abstract: A technique for delivering analog video over fiber-to-the-home (FTTH) networks addresses a fundamental problem of the standard signal format, i.e., power budget constraint, by increasing the usable optical signal efficiency. In particular, a technique is provided for transmitting an efficient modified analog video which is compatible with existing receivers. More specifically, the synchronization portion of a standard NTSC video signal is reduced in amplitude during transmission, producing an appreciable increase in the allowable optical modulation index (OMI).
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: November 24, 1998
    Assignee: Bell Communications Research, Inc.
    Inventor: Frank J. Effenberger
  • Patent number: 5708580
    Abstract: An apparatus for stabilizing an unmodulated video signal that has a sync tip voltage includes an amplifier for amplifying the video signal according to a control voltage, a transistor receiving the amplified video signal from the amplifier on the base of the transistor and outputting the amplified video signal on the collector, a sync tip voltage detector connected to the emitter of the transistor for detecting the sync tip voltage in the video signal and outputting a voltage derived from the sync tip voltage, an integrator having three inputs, one of which is the voltage derived from the sync tip voltage and another of which is a reference voltage and an output to the amplifier as the control voltage, a stabilization loop including a low current detector that detects low current levels in the amplified video signal through an optical coupler to a resistive element and a pulse stretcher that outputs a signal to the third input of the integrator, whereby the sync tip voltage detector, integrator and amplifier
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: January 13, 1998
    Assignee: Gilbarco, Inc.
    Inventor: Howard M. Myers
  • Patent number: 5512958
    Abstract: A television receiver having a microprocessor controlled disturbance control system that can operate totally under user control or automatically. The microprocessor generates an on-screen menu which presents noise control options to the user. In the preferred embodiment, the menu options allow the user to ameliorate the effects of impulse noise disturbances, longer duration disturbances, continuous wave form (CW) disturbances, or some combination of the three, without requiring the user to understand the nature of these disturbances. The present invention also provides compensation circuitry for reducing the effects of impulse noise in the video signal that is controlled by responding to the high frequency luminance signal produced by a comb filter, and also responding to the composite video picture signal. High frequency luminance and amplitude variations that are outside of the composite video signal range are indicative of the presence of impulse noise.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: April 30, 1996
    Assignee: Matsushita Electric Corporation of America
    Inventor: Thoedore S. Rzeszewski
  • Patent number: 5410364
    Abstract: AGC pulses and other undesirable signals are removed from a video signal by generating a replica of the AGC pulses or other signals and then mixing the replica with the original video to effect their removal.
    Type: Grant
    Filed: January 15, 1992
    Date of Patent: April 25, 1995
    Inventor: James A. Karlock
  • Patent number: 5361101
    Abstract: An RGB preamplifier for a video display includes respective multipliers independently operable for adjusting the contrast of input primary and secondary video signals. The contrast adjusted video signals are added to form a combined display signal, the combined signal being applied to the first inputs of primary and secondary comparators each of which is also supplied with a respective reference DC level. The primary and secondary video signals are alternately nulled at horizontal line rate by nulling the corresponding multipliers. The primary comparator samples the combined signal when the secondary signal is nulled for clamping the DC level of the primary signal in relation to the primary reference DC level and the secondary comparator samples the combined signal when the primary signal is nulled for clamping the DC level of the secondary signal in relation to the secondary reference DC level.
    Type: Grant
    Filed: November 19, 1993
    Date of Patent: November 1, 1994
    Assignee: Zenith Electronics Corporation
    Inventor: Khosro M. Rabii