Cathode-ray Tube Display Beam Current Control Patents (Class 348/380)
  • Patent number: 7950029
    Abstract: A method of interactive television providing for generating, transforming or displaying video information taking into account individual peculiarities of the user's eye and individual peculiarities of a group of viewer's eyes. The method provides simultaneously all or, at least, two operations from the above operations of formation, conversion and transmission of video signal and display of video information perceptible on the screen of information display facilities for one and/or a group of users or an unrestricted group of users. This is accomplished by one or a combination of various video editing and transmission adjustment techniques.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: May 24, 2011
    Inventors: Aleksandr Ivanovich Andreyko, Andrey Olegovich Kostrikin
  • Patent number: 7746396
    Abstract: A method of creating an image file in an imaging device, and an imaging device are provided. The method comprises providing an image sensor comprising pixels with an infrared filter arrangement so that some of the pixels of the sensor may be exposed to all wavelengths and some of the pixels of the sensor are blocked from infrared wavelengths. The pixels of the sensor that may be exposed to all wavelengths are utilized when taking an infrared image and the pixels of the sensor that are blocked from infrared wavelengths are utilized when taking a normal image.
    Type: Grant
    Filed: December 17, 2003
    Date of Patent: June 29, 2010
    Assignee: Nokia Corporation
    Inventors: Sami Mikkonen, Jaakko Kylmänen
  • Patent number: 7573389
    Abstract: A radio-frequency identification tag communication device including a BFA weight-value setting portion operable to control a directivity of a transmitter antenna, and an adaptive processing portion operable to implement an adaptive control of a weight to be given to a received signal received by each of a plurality of antenna elements, on the basis of a reply signal transmitted from a radio-frequency identification tag, so that the directivity of the transmitter antenna is changed to a direction in which the frequency identification tag in question is expected to exist, and the weight to be given to each received signal is subjected to the adaptive control, whereby the sensitivity of communication of the communication device with the radio-frequency identification tag is improved.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: August 11, 2009
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Yuji Kiyohara
  • Patent number: 7471344
    Abstract: An image display apparatus has a control circuit that periodically varies a characteristic, such as an amplitude characteristic or timing characteristic, of the displayed image signal. Periodic variations may be produced by passing the image signal through a variable inductance element, for example, or by alternately selecting two amplifier circuits with different gain characteristics, or by periodically delaying the image signal. The periodic variations reduce peaks in the spectrum of unintended radiation emissions, and suppress undesired moire patterns in the displayed image.
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: December 30, 2008
    Assignee: Mitsubishi Denki K.K.
    Inventor: Toshitsugu Wakabayashi
  • Patent number: 7286175
    Abstract: Bias control circuitry and method for use in controlling one or more cathode ray tube (CRT) beam currents.
    Type: Grant
    Filed: June 21, 2005
    Date of Patent: October 23, 2007
    Assignee: National Semiconductor Corporation
    Inventor: Charles Guan
  • Patent number: 7030908
    Abstract: Disclosed are a method and an apparatus for preventing appearance of a zigzag flush of light in a cathode-ray tube at the time of turning it off. A train of power-off control pulses are produced in synchronization with the vertical sweeping signal; a spot-killer control signal starts in synchronization with a selected power-off pulse to make the whole screen of the cathode-ray tube bright; and the power supply turns off in synchronization with another selected power-off control pulse, so that the power-off is caused at the termination of the vertical sweeping. Thus, the remaining static electricity is discharged at the lowermost of the screen of the cathode-ray tube. To assure that the residual static electricity is discharged completely, the length of time “t1” (continuing for a selected integer as long as the pulse-to-pulse duration) is determined to meet the size of the cathode-ray tube.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: April 18, 2006
    Assignee: Orion Electric Co., Ltd.
    Inventor: Kazuyuki Iji
  • Patent number: 6998782
    Abstract: Based, in part, on an input video signal, an autobias circuit generates red, green, and blue channel video signals, which are received by external drivers to drive cathodes in a CRT. The autobias circuit also provides gain and bias control signals based on a sense current. The external drivers generate the sense current such that the sense current is proportional to the sum of the beam currents flowing from the cathodes. The sense current has an error caused by current flowing through external recharge resistors. A correction current (Ivideo) is subtracted from the sense current to compensate. The correction current is generated according to the equation Ivideo=(Vs/Rkin)*[(Vref/Rext)/(Vref/Rin)], where Vkin and Rin are matched internal monolithic resistors, Rext is the resistance of another external resistor that is matched to the external recharge resistors, and Vs is the sum of the red, green, and blue channel video signals.
    Type: Grant
    Filed: August 18, 2004
    Date of Patent: February 14, 2006
    Assignee: National Semiconductor Corporation
    Inventor: Charles Guan
  • Patent number: 6989639
    Abstract: In a configuration equipped with an anode current detecting resistor connected between a ground side terminal of secondary coils wound around a flyback transformer and generating a high voltage for an anode of a CRT, it is equipped with declination detecting device which detects declination of a voltage of the ground side terminal, and control device which stops an operation of a horizontal output transistor, after a state is shifted from a power OFF state to a power ON state, when the declination detecting device 5 does not detect declination of a voltage of the ground side terminal in case that a predetermined period has passed.
    Type: Grant
    Filed: June 17, 2004
    Date of Patent: January 24, 2006
    Assignee: Funai Electric Co., Ltd.
    Inventor: Koji Kamizawa
  • Patent number: 6972805
    Abstract: An apparatus displays a video signal (VID) by means of a scan (SCAN). The apparatus may be, for example, a television set. The apparatus comprises a device (SCAVEM) for modulating the scanning rate (Vscan) as a function of the derivative (DLUM) of a luminance signal (LUM) extracted from the video signal (VID). This enables the subjective display quality to be improved. The apparatus has the following characteristic feature in order to obtain an even better quality, notably when the apparatus is used for displaying video signals of different types. The derivative (DLUM) of the luminance signal, as a function of which the scanning rate (Vscan) is modulated, is obtained by means of a difterentiator circuit (DIFF) having a controllable frequency response (CFR).
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: December 6, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Philippe Vilard, Marnik Bogaert
  • Patent number: 6970203
    Abstract: The automatic cut-off system includes a video data processing circuit, a cut-off control circuit, a drive circuit, and a level control section. The video data processing circuit adds a cut-off reference pulse having a predetermined level to primary-color signals of red (R), green (G) and blue (B) at different timings within a single vertical blanking interval, and outputs latch timing signals respectively indicating the timings. The cut-off control circuit shifts a level of each primary-color signal having the cut-off reference pulse added thereto based on a corresponding cut-off control signal. The drive circuit drives each cathode of a CRT (cathode-ray tube) based on a corresponding one of the shifted primary-color signals, and outputs a voltage corresponding to each cathode current as a common feedback signal. The level control section latches the feedback signal in response to each latch timing signal, and outputs the cut-off control signal of one of the primary-color signals.
    Type: Grant
    Filed: August 22, 2002
    Date of Patent: November 29, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yutaka Otani, Masahiko Sasada, Nobuo Taketani, Masahiro Takeshima, Hiroshi Moribe
  • Patent number: 6937288
    Abstract: In a beam current limiting circuit for a video projector, an average current is limited under closed loop control containing an anode current detection circuit 5. On the other hand, a cathode current detection circuit 107 comprises a first resistor and a second resistor in series to a cathode current circuit and detects a cutoff current at the voltage across the first resistor and an average current at the voltage across the second resistor. An offset addition circuit 11 is provided for correcting the detection value of the average current based on the maximum value of detected cathode current, and beam current is limited. Further, means 15 for detecting time change of anode current is provided and if the current value does not change for a long time, the beam current is limited to a smaller value.
    Type: Grant
    Filed: April 19, 2001
    Date of Patent: August 30, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Taketoshi Hibi
  • Patent number: 6904151
    Abstract: The present invention relates to the methods of estimation and recovering of general affine geometrical transformations which were applied to data, extensible to any other defined class of geometrical transformations, according to the preamble of the dependent claims. The parameters of the undergone deformation are robustly estimated based on maxima given by a parametric transform such as Hough transform or Radon transform of some embedded information with periodical or any other known regular structure. The main applications of this invention are robust digital still image/video watermarking, document authentication, and detection of periodical or hidden patterns. In the case of periodical watermarks, the watermark can also be predistorted before embedding based on a key to defeat block-by-block removal attack.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: June 7, 2005
    Inventors: Frédéric Deguillaume, Sviatoslav Voloshynovskiy, Thierry Pun
  • Patent number: 6897900
    Abstract: A display apparatus, for instance a television receiver, comprises a cathode ray tube, a first circuit for providing a high voltage to the cathode and a second circuit receiving a gross signal and providing on at least an output at least a luminance signal controlling an electron stream of the cathode ray tube. To reduce stray emission, absence of gross signal is simulated when the apparatus is switched from on to off.
    Type: Grant
    Filed: June 14, 2000
    Date of Patent: May 24, 2005
    Assignee: Thomson Licensing S.A.
    Inventors: Yew Honn Cheong, Kyaw Nyunt Maung
  • Patent number: 6897901
    Abstract: A control circuit for use in a video processor utilizes combined automatic kinescope bias (AKB) control, and average individual beam current sensing and limiting in at least one CRT. The control circuit includes automatic kinescope bias (AKB) control circuitry for detecting a magnitude of individual red (R), green (G) and blue (B) cathode currents driving corresponding R, G and B CRTs, generating R, G and B average cathode current control signals therefrom, and using the R, G and B average cathode current control signals as feedback to the video processor to reduce the R, G and B cathode currents approximately equal current amounts.
    Type: Grant
    Filed: December 13, 2001
    Date of Patent: May 24, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: William G. Miller
  • Patent number: 6891564
    Abstract: An apparatus for controlling aging, cathode ray tube aging including a microcontroller generating brightness level data for aging of the cathode to a video input signal; a video preamplifier connected to the microcontroller receiving the brightness level data by the video input signal and mixing a host video signal to generate a video output signal wherein the brightness level of the video output signal being controlled by the microcontroller; a cutoff control coupled to the video preamplifier receiving brightness data of the video output signal and setting a proper brightness level of a cathode; and a voltage control not coupled to the microcontroller preset for a an initial brightness level of the cathode during aging.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: May 10, 2005
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventors: Shin Fujimori, Hiyouki Nakazono, Toshinori Hamada
  • Patent number: 6888575
    Abstract: An improved digital cut-off control loop for black level adjustment in a video processor for controlling RGB output signals. The improved circuit advantageously provides a higher resolution of the black level adjustment, and a short cut-off convergence time when the TV set is switched on. The improved circuit can also blank the RGB output when the cut-off control loop has not converged to the correct level.
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: May 3, 2005
    Assignee: STMicroelectronics Asia Pacific Pte. Ltd.
    Inventors: Yann Desprez-Le Goarant, Jean-Luc Jaffard, Christian Michon
  • Patent number: 6885531
    Abstract: An over-current protection circuit is used to prevent damage to a television receiver due to excessive beam current. The television receiver includes a high voltage generating circuit for supplying a beam current to a picture tube. The over-current protection circuit a measurement circuit for directly detecting the beam current, a comparison circuit for comparing the detected beam current with a predefined threshold level, and an output circuit coupled to a control input of the high voltage generating circuit, for generating a control signal for turning off the high voltage generating circuit.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: April 26, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Pak Chong Tang
  • Patent number: 6870575
    Abstract: A screen-noise eliminating apparatus including beam-spot-length control means for increasing or decreasing the vertical length of a beam spot on a display screen generated by an electron of a cathode-ray tube for displaying a TV signal; vertical enhancement means for enhancing a given vertical-direction spatial frequency characteristic of said TV signal; and noised elimination control means for controlling said beam-spot-length control means and said vertical enhancement means so as to compensate according to the increase of decrease of said beam spot length.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: March 22, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Taketoshi Hibi, Hiroshi Sasaki
  • Publication number: 20040212740
    Abstract: A method for controlling dissipation in a video amplifier for a display signal. The method comprises the steps of setting a first current for establishing a first gain bandwidth product in the video amplifier. Generating a control signal in accordance with a slew rate of the display signal. Modifying the first current responsive to the control signal such that the video amplifier gain bandwidth product is controlled in accordance with the slew rate of said display signal.
    Type: Application
    Filed: February 10, 2004
    Publication date: October 28, 2004
    Inventor: Anton Werner Keller
  • Patent number: 6806908
    Abstract: A cathode current limiting circuit and method, for use with projection color television display systems to prevent overheating and possible cracking of the blue cathode ray tube (CRT) when a continuous blue background is presented, monitors differences between the respective low level red, green, blue (RGB) signals sent from the video signal processor to the CRT drive which produces the respective RGB cathode or beam currents. When the low level blue signal exceeds both of the red and the green signals by a predetermined differential, the circuit sends a feedback signal to the video signal processor to limit the blue signal and, thus, the cathode current from the CRT drive.
    Type: Grant
    Filed: August 10, 2001
    Date of Patent: October 19, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: William G. Miller
  • Publication number: 20040183944
    Abstract: A cathode ray tube device has a vacuum envelope including a panel, a funnel and a neck. A deflection yoke is mounted to a yoke-mounting portion of the funnel. The deflection coil includes a horizontal deflection coil, a vertical deflection coil, a separator provided between the coils, and a hollow core surrounding the coils. The sectional shape of at least an outer surface of the hollow core varies from a circular shape to a substantially barrel shape, along the tube axis from the neck side to the panel side. The substantially barrel shape has a maximum dimension at least in a direction of the horizontal axis or the vertical axis.
    Type: Application
    Filed: December 3, 2003
    Publication date: September 23, 2004
    Inventors: Kiyoshi Aoki, Yoshihito Matsuura, Hiroaki Nishino, Junichi Igarashi
  • Patent number: 6771023
    Abstract: A system for regulating beam current in a cathode ray tube. The system includes test signal timing and pulse generation logic for outputting test signals operable to stimulate a cathode ray tube at two voltage levels. The system further includes a circuit that inputs the test signal timing and determines correction signals based on signals derived from the cathode in response to stimulating the cathode ray tube at the two voltage levels. The correction signals may include a gain correction signal, a bias correction signal or both. The gain correction signal modifies a signal output to a gain driver that may be AC coupled to the cathode. The bias correction signal output to a clamping circuit coupled to the cathode.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: August 3, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Charles Guan, Andrew Morrish
  • Publication number: 20040114040
    Abstract: The present invention provides improved burnout imprinting prevention by slowly moving the position of screen content to ensure that no one area of the guns is unused for a long period of time. Optical and/or mechanical elements are provided to redirect the projected image to the center of the screen. As the image moves on the projection guns the optical elements are positioned accordingly to shift the projected image such that the viewable image is fixed.
    Type: Application
    Filed: December 12, 2002
    Publication date: June 17, 2004
    Applicant: International Business Machines Corporation
    Inventors: Thomas Alexander Bellwood, Leugim A. Bustelo, Julio Eloy Ruano, Matthew Francis Rutkowski
  • Patent number: 6686710
    Abstract: A circuit for regulating a signal, such as a cathode current. The circuit has an input stage for inputting a signal and for producing a sense signal based thereon. The circuit may input timing signals and have a first stage for comparing a first reference signal with the sense signal when a first timing signal indicates and for outputting a first correction signal based on the comparison. The circuit may have a second stage for comparing a second reference signal with the sense signal when a second timing signal indicates and for outputting a second correction signal based on the comparison. The circuit may further have elements for measuring a leakage signal in the input signal during a third time interval. In this embodiment, the first and second stages are further for subtracting the leakage signal from the sense signal prior to the comparisons.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: February 3, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Charles Guan, Andrew Morrish
  • Patent number: 6664725
    Abstract: A CRT electron gun of the present invention has a cathode for emitting electrons toward a screen as a display face, a G2 electrode to which a voltage higher than that of the cathode is applied, a Gm electrode to which a predetermined voltage is applied, and a G3 electrode to which a voltage higher than that of the G2 electrode is applied, wherein at least those three electrodes are provided with an electron-passing opening and are arranged on the same axis in that order from the side of the cathode, and the potential of the aforementioned cathode is varied to vary the amount of electrons to be drawn; and in this, a configuration is made such that the lowest potential on the axis in a portion where the aforementioned Gm electrode exists substantially agrees with the maximum potential in a range where the potential of the aforementioned cathode varies, and a part of the electrons drawn from the aforementioned cathode flows into at least one of the aforementioned G2 electrode and the aforementioned Gm electrode.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: December 16, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tetsuya Shiroishi, Syuhei Nakata
  • Patent number: 6636265
    Abstract: An inventive method for preventing focus flutter display in a TV receiver or monitor includes the steps of amplifying a received signal for driving cathode elements of a cathode ray tube, and delaying initial full amplification of the signal during the amplifying step for a duration sufficient to prevent focus flutter display on the tube. A corresponding inventive kine driver circuit that prevents display of focus flutter includes an amplifier for amplifying and coupling received video signals to cathode elements of a picture tube, and a control circuit for delaying full amplification of the video signals to be fed to the cathode elements for a duration sufficient to prevent focus flutter display on the tube.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: October 21, 2003
    Assignee: Thomson Licensing S.A.
    Inventor: Isaac Michael Bell
  • Patent number: 6614482
    Abstract: A video processing system includes a video output driver stage which is capable of automatically self-regulating the peak beam current output provided to a display. The system includes a video output driver stage with a video signal input and a video signal output for providing an amplified video signal. The video output driver stage comprises means for amplifying the video signal input to form the video signal output and conveying the amplified video signal output to the image reproducing display device. The system further comprising a sensing output for providing thereat a sensed signal representative of current conducted by said image reproducing display device. The system also includes a sensing and control means for sensing the sensed signal and for providing a feedback signal to an input component of the video output driver stage for limiting the current conducted by said image reproducing display device to a predetermined value.
    Type: Grant
    Filed: November 24, 1999
    Date of Patent: September 2, 2003
    Assignee: Thomson Licensing S.A.
    Inventor: Dal Frank Griepentrog
  • Patent number: 6563276
    Abstract: A CRT display apparatus capable of displaying images in high contrast and high brightness without causing noises and halftone-reproduction degradation within dark areas is disclosed. The apparatus includes a circuit for generating an R-control signal, a G-control signal and a B-control signal by removing, from each of the R-, G- and B-video signals, portions which are below a predetermined level in amplitude, an amplification circuit for inverting and amplifying the R-, G- and B-control signals, and a selection circuit for selecting, for each of the three G1 electrodes, either a corresponding one of the R-, G- and B-control signals inverted and amplified by the amplification circuit or a potential of a predetermined value in accordance with an instruction from an outside, and applying each of the three G1 electrodes with a selected one of the corresponding one of the R-, G- and B-control signals and the potential.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: May 13, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akinori Heishi, Hironobu Yasui, Tetsuya Shimizu
  • Patent number: 6563552
    Abstract: Provided are an image correcting method and device capable of reducing power consumption necessary for correcting an image for a long-time use and a cathode ray tube display unit. A microcomputer 2 calculates a value of a correction current in such a manner that the correction current is more decreased monotonously as a time passes after a cathode ray tube is turned on. Drivers 3 to 7 and 22 generate and output the correction current according to the value of the correction current calculated by the microcomputer 2. A correcting device C is provided in the cathode ray tube and serves to correct an image displayed on the cathode ray tube on receipt of the correction currents from the drivers 3 to 7 and 22.
    Type: Grant
    Filed: October 27, 1999
    Date of Patent: May 13, 2003
    Assignee: NEC-Mitsubishi Electric Visual Systems Corporation
    Inventor: Takeshi Chujo
  • Patent number: 6556254
    Abstract: In a black and white level stabilization device, an OSD signal generator (OSD-SG) generates black and white reference signals (OSD-R/G/B), amplifying circuits (VA-R/G/B) amplify the black and white reference signals (OSD-R/G/B) or RGB signals (Ri, Gi, Bi), and a measuring circuit (PNP-R/G/B, RM), coupled to the amplifying circuits (VA-R/G/B), measures a white level and a black level in response to the black and white reference signals (OSD-R/G/B).
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: April 29, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Augusto Palmero
  • Patent number: 6552752
    Abstract: When an STB is powered off when it is not used (when it is changed to the sleep mode) for the purpose of power-saving, a difference in a subtracter immediately therebefore is held by a control circuit and an oscillation circuit is controlled on the basis of the difference, thereby performing reserved processing at a correct time even when the STB is in the sleep mode.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: April 22, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshiaki Tsuji, Toshiroh Nishio
  • Patent number: 6549246
    Abstract: In a projection CRT, an image of high brightness is displayed on a screen as an electron beam emitted from an electron gun is scanned according to an image driving signal. The image is magnified and projected through a lens unit. Here, voltage of a direct current component of the image driving signal is lower than threshold voltage of the screen for scan time and also lower than threshold voltage of the electron gun for retrace time.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: April 15, 2003
    Assignee: Samsung Display Devices Co., Ltd.
    Inventors: Sang-kyun Kim, Duk-sung Park
  • Patent number: 6545717
    Abstract: A display system (10) which includes a CRT feedback current simulating circuit (20) to simulate the cathode feedback current directly from the from the red, green and blue output biases of the video processor (13). Furthermore, the display system (10) applies blanking to the references pulses applied to the CRT output driving stage (16) so that the reference pulses will not be visible during a vertical underscanned condition. Shifting the generation of the cathode feedback current prior to the application of the blanking prevents any significant distortion, modification or skewing of the cathode feedback current sensed by the AKB sensing circuitry (19) of the video processor (13).
    Type: Grant
    Filed: September 26, 2001
    Date of Patent: April 8, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: William G. Miller, Mark Laramie, Gregg Keck
  • Patent number: 6538398
    Abstract: A circuit for driving a cathode ray tube (CRT) with cathode current detection. Specifically, the present invention discloses a CRT driver circuit comprising a push-pull configuration comprising upper and lower stages of darlington paired transistors. In the lower stage, a lower prestage circuit generates a video output signal in response to a video input signal that is amplified to drive a cathode electrode of a coupled CRT. In the upper stage, an upper prestage circuit of transistors drives a voltage divider for splitting a high voltage supply between the transistors in the lower prestage circuit. In both the upper and lower stages of darlington paired transistors, upper and lower output stages of transistors are electrically active only during transient periods of the video input signal. As such, a cathode current from a static test signal can be measured from an output through the lower prestage circuit.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: March 25, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Hon Kin Chiu
  • Publication number: 20030035062
    Abstract: The invention relates to a method for displaying a television picture or monitor picture on a display screen. In order to achieve a largely line-free display while degrading the vertical contrast of the picture as little as possible, an approach is proposed in which a vertical contrast value is determined from a video input signal (Y), the vertical contrast value is compared with a limiting value (a, b), and a vertical widening of a light spot region of the lines covered by the scanning beam is set as a function of this comparison, preferably by a vertical sweep of the scanning beam. If the vertical contrast value is below the limiting value (a, b), a smaller vertical widening of the light spot region is set than if the vertical contrast value is above the limiting value (a, b).
    Type: Application
    Filed: June 21, 2002
    Publication date: February 20, 2003
    Inventor: Peter Flamm
  • Patent number: 6489994
    Abstract: A method and device utilizes a brightness control circuit for protecting a cathode ray tube in an image displaying device. The displaying device has an image signal amplifier, a cathode ray tube, and a brightness control circuit. The cathode ray tube has a screen, an electron gun, and an anode for collecting an electron beam emitted onto the screen to produce an anode current. The brightness control circuit is electrically connected to a control end of the image signal amplifier for controlling the amplification magnitude of the image signal amplifier and electrically connected with the anode of the cathode ray tube via a flyback transformer, wherein when the incoming image signals make the image picture shown on the screen too bright, the anode current of the anode will be increased accordingly, and the brightness control circuit will reduce the amplification magnitude of the image signal amplifier at the same time according to the increase of the anode current so as to reduce the anode current.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: December 3, 2002
    Assignee: Benq Corporation
    Inventor: Hsieh Chang-Fa
  • Patent number: 6486900
    Abstract: A system for minimizing screen burn on a display screen caused by the display of video images that do not occupy the entire area of the display screen includes video image processing circuitry for formatting a received video signal to display an active image of the video signal on a portion of the display screen, and for displaying a screen saver on portions of the display screen that are not occupied by the formatted active image. A screen saver library provides a screen saver from a plurality of screen savers. Each screen saver in the plurality of screen savers occupies portions of the display screen that are not occupied by an active image.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: November 26, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Richard Chi-Te Shen, Alan Peter Cavallerano
  • Patent number: 6483557
    Abstract: Unintentional emissions are controlled responsive to the spectral content of the display signal. A video display apparatus comprises a cathode ray tube responsive to a video signal. A processor controls a bandwidth of the video signal coupled to the cathode ray tube in response to an emission control signal. A generating device is coupled to the processor for generating the emission control signal responsive to a component of the video signal.
    Type: Grant
    Filed: November 5, 1999
    Date of Patent: November 19, 2002
    Assignee: Thomson Licensing SA
    Inventors: Jeffrey Owen Allender, Dal Frank Griepentrog, Brian Jonathan Cromarty
  • Publication number: 20020130966
    Abstract: An automatic beam limiter circuit (ABL circuit) calculating an average of a video signal at least a portion of the video signal is provided. After a converter circuit converts an analog signal, which is generated from the video signal, to a digital signal, a horizontal and a vertical average circuits calculate a horizontal and vertical averages of the digital signal at least a portion of the digital signal. The portion of the digital signal is a scanned line of the digital signal on a CRT. A comparison circuit compares a first calculation value calculated between a reference value and the vertical average with a second calculation value calculated between the reference value and the horizontal average, and outputs a first comparison signal and a second comparison signal based on the comparison results. A gain control circuit produces a gain control signal for adjusting the brightness/contrast in response to the first comparison and second comparison signals.
    Type: Application
    Filed: November 28, 2001
    Publication date: September 19, 2002
    Applicant: Samsung Electronics Co., Ltd.
    Inventor: Sung-Uk Park
  • Publication number: 20020130965
    Abstract: A control circuit for use in a video processor utilizes combined automatic kinescope bias (AKB) control, and average individual beam current sensing and limiting in at least one CRT. The control circuit includes automatic kinescope bias (AKB) control circuitry for detecting a magnitude of individual red (R), green (G) and blue (B) cathode currents driving corresponding R, G and B CRTs, generating R, G and B average cathode current control signals therefrom, and using the R, G and B average cathode current control signals as feedback to the video processor to reduce the R, G and B cathode currents approximately equal current amounts.
    Type: Application
    Filed: December 13, 2001
    Publication date: September 19, 2002
    Applicant: KONINLIJKE PHILIPS ELECTRONICS N.V.
    Inventor: William G. Miller
  • Publication number: 20020047913
    Abstract: In a period from temporal storage of a video signal to reading and displaying of the video signal, an average value 121 of the brightness levels obtained from a video signal before the video signal is stored in a storage means 3 and a predetermined target value 122 are used to perform a calculation by using a proportionality term and an integration term so that a quantity of limited electric currents is obtained. Moreover, the quantity of limited electric currents is provided with a non-response region or a hysteresis characteristic.
    Type: Application
    Filed: January 26, 1998
    Publication date: April 25, 2002
    Inventors: YOSHIKI ONO, JUN SOMEYA, YOSHIAKI OKUNO
  • Publication number: 20020001040
    Abstract: In a beam current limiting circuit for a video projector, an average current is limited under closed loop control containing an anode current detection circuit 5. On the other hand, a cathode current detection circuit 107 comprises a first resistor and a second resistor in series to a cathode current circuit and detects a cutoff current at the voltage across the first resistor and an average current at the voltage across the second resistor. An offset addition circuit 11 is provided for correcting the detection value of the average current based on the maximum value of detected cathode current, and beam current is limited. Further, means 15 for detecting time change of anode current is provided and if the current value does not change for a long time, the beam current is limited to a smaller value.
    Type: Application
    Filed: April 19, 2001
    Publication date: January 3, 2002
    Inventor: Taketoshi Hibi
  • Patent number: 6313878
    Abstract: A hardware-implemented screen-saver prevents burn-in of an image displayed on a screen of a display product by automatically reducing the video gain, and therefore the contrast, of the image when the portion of the image within a two-dimensional detection window has changed by less than a predetermined amount for a predetermined period of time. A lack of change of the incoming video signal of the image is detected and used to invoke a reduction in contrast of the image displayed on the display product. This allows the image to remain visible, yet reduces the possibility of burn-in of the image in the screen of the display product.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: November 6, 2001
    Assignees: Sony Corporation, Sony Electronics, Inc.
    Inventor: Patrick Joseph Jankowiak
  • Patent number: 6285401
    Abstract: Display apparatus includes a kinescope cathode current sensor (18) coupled to a load (200) for developing a beam current measurement pulse during a beam current measurement interval. Overshoots in the pulses are suppressed by a pulse correction circuit (300) comprising a first capacitor (Ca) coupled from the load circuit (200) to a source of reference potential (Gr) via a switch (Q300); and a control circuit (Ca, Ra, Rb), responsive to the presence of the overshoot, for closing the switch for a predetermined length of time and for opening the switch otherwise.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: September 4, 2001
    Assignee: Thomson Licensing S.A.
    Inventor: Dal Frank Griepentrog
  • Patent number: 6226037
    Abstract: An AKB interface apparatus in a display system (10), includes a video signal processing IC (12) having outputs coupled via respective kinescope driver ICs (18,20,22) to respective kinescope cathodes (K1,K2,K3) for display of a color image, the signal processing IC having an input 27 for receiving an AKB input signal, the driver ICs having respective outputs (28,30,32) providing respective cathode current indicating signals (RP,GP,BP) An interface circuit (100) couples the cathode current indicating signals to the AKB input of the signal processing IC. The interface circuit comprises a load circuit (110) for generating a load voltage (Vo) in response to at least one of the cathode current indicating signals. A leakage correction circuit (130), responsive to said load voltage (Vo), feeds back a leakage correction current (Io) to the load circuit.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: May 1, 2001
    Assignee: Thomson Licensing S.A.
    Inventor: Dal Frank Griepentrog
  • Publication number: 20010000217
    Abstract: In a period from temporal storage of a video signal to reading and displaying of the video signal, an average value 121 of the brightness levels obtained from a video signal before the video signal is stored in a storage means 3 and a predetermined target value 122 are used to perform a calculation by using a proportionality term and an integration term so that a quantity of limited electric currents is obtained. Moreover, the quantity of limited electric currents is provided with a non-response region or a hysteresis characteristic.
    Type: Application
    Filed: December 8, 2000
    Publication date: April 12, 2001
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshiki Ono, Jun Someya, Yoshiaki Okuno
  • Patent number: 6204882
    Abstract: Recent circuit concepts inject measurement lines, for cutoff and drive control of the cathode current, into each color channel during the vertical frame blanking period. Owing to the physically dependent exponential beam current characteristic profile as a function of the cathode control voltage VK, the exponent &ggr; of the characteristic profile and the ratio of two cathode components IK1 and IK2 may be used to form control reference values for cutoff and drive control, this process being started in each case from a fixed value of the exponent &ggr; or of the ratio of the two cathode currents IK1 and Ik2. However, it has been found that, if a fixed value is assumed for the exponent &ggr; or for the ratio of the two cathode currents IK1 and IK2, it is not possible to achieve an optimum result for displaying monochrome pictures. Thus, according to the invention, the exponent &ggr; is defined as a function of the color tube 1. The aim in this case is to reduce a &ggr;-dependent DC voltage offset u0f to zero.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: March 20, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventor: Helmut Sowig
  • Patent number: 6195134
    Abstract: A horizontal electron-beam deflector capable of preventing circuits from being damaged due to disturbance such as electric discharge with a simple and small circuit configuration, wherein an AFC circuit inputs a control signal indicating a frequency from a computer, the control signal is output to a deflection circuit, the AFC circuit generates a horizontal synchronization pulse signal, and the deflection circuit generates a horizontal deflection signal while controlling a voltage by using the control signal input from the AFC circuit.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: February 27, 2001
    Assignee: Sony Corporation
    Inventors: Shinji Takahashi, Takatomo Nagamine
  • Patent number: 6188435
    Abstract: A circuit for controlling beam current in a picture tube, which circuit calculates current pictures for the R, G, B beam currents in the picture tube, which largely correspond to real beam currents in the color picture tube. The circuit comprises a comparator/integrator which compares a sum of these current pictures with a beam current information item for the purpose of controlling the R, G, B beam currents and/or the picture sharpness. Gamma correction is carried out in the circuit. The circuit may be of analog or digital construction and may advantageously be integrated in a video processor IC. The present circuit is particularly applicable for television sets or computer monitors.
    Type: Grant
    Filed: March 4, 1998
    Date of Patent: February 13, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Hossein Ahmari, Gerard Rilly
  • Patent number: 6169587
    Abstract: A circuitry for attaining a fixed raster vertical scan size of a video display apparatus is proposed. The video display apparatus comprises a flyback transformer (FBT) which includes a primary winding and a secondary winding. The secondary winding has a terminal generating a high voltage to an anode of a cathode ray tube (CRT) of the video display apparatus via an external loading. Moreover, the secondary winding has a voltage reference terminal. The raster vertical scan size adjustment circuit comprises a compensation circuit and a raster vertical scan size control circuit. The compensation circuit includes an input terminal adapted to connect the voltage reference terminal of the secondary winding for detecting voltage change at the voltage reference terminal responsive to variation of the external loading. The compensation circuit has an output terminal generating the compensated signal.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: January 2, 2001
    Assignee: Acer Peripherals Inc.
    Inventor: Hsieh Chang-Fa