Intensity Control Patents (Class 345/63)
  • Patent number: 7463220
    Abstract: A plasma display device and a method of driving a plasma display panel are provided for improving the contrast without degrading the image quality. Each of display cells formed on the plasma display panel has a magnesium oxide layer containing magnesium oxide crystals. The magnesium oxide crystals are excited by an electron beam irradiated thereto and emit cathode luminescence light having a peak in a wavelength range of 200 to 300 nm. In order to trigger a rest discharge in all the display cells, each row electrode pair of the plasma display panel is applied with a reset pulse which has a particular pulse waveform. The voltage value of this reset pulse slowly changes over time to reach a peak voltage value.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: December 9, 2008
    Assignee: Pioneer Corporation
    Inventors: Kazuaki Sakata, Masaru Nishimura, Atsushi Hirota, Tsutomu Tokunaga, Hai Lin
  • Patent number: 7463221
    Abstract: A plasma display device. A plasma display panel includes a plurality of address electrodes, a plurality of scan electrodes, and a plurality of sustain electrodes. A temperature detector detects a temperature of the plasma display panel. A controller outputs a scan electrode driving signal to control a reset waveform to be applied during reset periods of a first number of subfields when the detected temperature between a first temperature and a second temperature, and to control a reset waveform to be applied during reset periods of a second number of subfields when the detected temperature is lower than the first temperature and higher than the second temperature. The second number of subfields is greater than the first number of subfields. A scan electrode driver applies the appropriate reset waveform during a reset period of a subfield according to the scan electrode driving signal output from the controller.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: December 9, 2008
    Assignee: Samsung SDI Co., Ltd.
    Inventor: Myoung-Kwan Kim
  • Patent number: 7463218
    Abstract: A method and apparatus for driving a plasma display panel that is adaptive for improving a sustain driving margin. In the method and apparatus, the number of sustaining pulses is set in response to an average picture level. A period of the sustaining pulse is set in proportion to said average picture level.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: December 9, 2008
    Assignee: LG Electronics Inc.
    Inventors: Sang Jin Yun, Seong Ho Kang
  • Patent number: 7460087
    Abstract: The present invention relates to a drive device and method of a plasma display panel in which the manufacturing cost of a PDP can be reduced. The plasma display panel in accordance with the present invention has a drive device comprising: a IC circuit supplying drive voltage to scan electrodes; a energy recovery circuit supplying sustain voltage to the IC circuit; a set up supply part supplying rising ramp wave form to the IC circuit during set up period; and a set down supply part supplying falling ramp wave form to the IC circuit during set down period, wherein said drive device includes a switch which connects the set up supply part to the set down supply part and is turned on or off responding to voltage supplied to the IC drive circuit during the set down period.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: December 2, 2008
    Assignee: LG Electronics Inc.
    Inventors: Tae Hyung Kim, Jeong Pil Choi
  • Patent number: 7460088
    Abstract: A plasma display apparatus, in which the display quality of a dark image is improved and which uses a subfield method, has been disclosed. The plasma display apparatus comprises a plasma display panel, a sustain pulse cycle changing means for detecting the display load ratio of each subfield and changing the sustain pulse cycle of each subfield according to the display load ratio, and an adaptive subfield number changing means for calculating a vacant time in a display frame generated by changing the sustain pulse cycle, judging whether a subfield can be added according to the vacant time, and determining the number of subfields in the display frame.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: December 2, 2008
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Masanori Takeuchi, Yasuji Noguchi, Yutaka Chiaki, Shunji Oota
  • Publication number: 20080291133
    Abstract: A plasma display according to an exemplary embodiment of the present invention applies different driving methods according to a maximum grayscale level of image data input for one field. When the maximum grayscale level of the field is higher than a reference level, an address period for selecting a light emitting cell and a non-light emitting cell from a plurality of discharge cells and a sustain period for sustain-discharging light emitting cells among the plurality of discharge cells are simultaneously driven in a plurality of sequential subfields after a first subfield. When the maximum grayscale level of the field is less than the reference level, the address period and the sustain period are time-separately driven in the plurality of subfields.
    Type: Application
    Filed: April 24, 2008
    Publication date: November 27, 2008
    Inventors: Hyun-Seok Nam, Kang-Hee Lee, Soo-Hyun Kim, Tae-Kyoung Kang
  • Patent number: 7456808
    Abstract: There is disclosed visual artifact reduction methods for a display comprising the use of gamma corrections, error diffusion, dithering, and/or center of light. The invention is described with reference to an AC gas discharge display (PDP), but may be practiced with other display technologies. The methods of this invention are disclosed for use with a number of PDP structures and PDP electronic addressing architectures including ADS, SAS, and ALIS. In one preferred embodiment, a center of light timing method is used to reduce artifacts between different sections of a PDP being addressed with SAS architecture.
    Type: Grant
    Filed: February 2, 2004
    Date of Patent: November 25, 2008
    Assignee: Imaging Systems Technology
    Inventors: Carol Ann Wedding, Jeffrey W. Guy
  • Publication number: 20080284687
    Abstract: A display apparatus, that can prevent thermal destruction and burning with a simple structure, has been disclosed. In the apparatus it is judged that there is possibility of a pattern, whose area with high brightness is small, being displayed frequently, when a state in which the total light emission pulse number remains large occurs with high frequency, and if such a state is detected, the total light emission pulse number (sustain frequency) is reduced to prevent the thermal destruction and burning.
    Type: Application
    Filed: July 11, 2008
    Publication date: November 20, 2008
    Applicant: FUJITSU HITACHI PLASMA DISPLAY
    Inventors: Ayahito Kojima, Shigeki Kameyama, Hirohito Kuriyama, Yoshikazu Kanazawa, Toshio Ueda
  • Publication number: 20080284686
    Abstract: When a sustain discharge corresponding to the display light is repeatedly produced by applying a drive pulse to a PDP which includes a fluorescent layer in the discharge cells, the drive pulse waveform is adjusted in accordance with the total number of sustain discharges. Furthermore, an auxiliary pulse of the same polarity as that of the sustain pulse is applied to the column electrodes in a period from after the application of a final scan pulse in the address process until the application of a leading sustain pulse. A period from the final sustain pulse until the time of the application of the leading pixel data pulse which is applied first in the write address process of the one subfield of the subsequent frame is made 1 millisecond (msec) or more.
    Type: Application
    Filed: May 12, 2008
    Publication date: November 20, 2008
    Applicant: Pioneer Corporation
    Inventors: Takashi Mashita, Hajime Homma, Koji Hashimoto, Yuichi Sakai, Ayuhiko Saito, Mitsuhiro Ishizuka
  • Publication number: 20080284683
    Abstract: In a plasma display device, one frame is divided into a plurality of subfields, each having a weight, a first subfield to which more than a reference number of sustain pulses are allocated among the plurality of subfields is detected, at least N first sustain pulses are applied to the plasma display device during a sustain period of the first subfield, and at least M second sustain pulses are applied to the plasma display device during a sustain period of the first subfield. The first and second sustain pulses respectively have a high level voltage and a low level voltage, and a first period during which the first sustain pulse is changed from the low level voltage to the high level voltage is longer than a second period during which the second sustain pulse is changed from the low level voltage to the high level voltage.
    Type: Application
    Filed: April 11, 2008
    Publication date: November 20, 2008
    Inventors: Sang-Young Lee, Kwang- Ho Jin, Jung-Jin Choi
  • Patent number: 7453423
    Abstract: A plasma display improved in variation of display brightness between unit cells. A control circuit sets, for every pulse, a charge-recovering time period for recovering a charge on a capacitance component of the plasma display panel and a clamp timing period for applying a predetermined sustain voltage to the sustain electrodes or the scan electrodes after the charge-recovering time period through clamp start timing, and sets a sustain-discharge emission intensity ratio, as a ratio of a maximal discharge intensity in the clamp timing period with reference to a discharge intensity in the clamp start timing to a maximum discharge intensity in the charge-recovering time period, at a value that a discharge in the clamp timing period is to spread up to an end of the unit cell. For example, the control circuit sets a sustain-discharge emission intensity ratio substantially at 0.5 or greater or 0.1 or smaller, thus eliminating the occurrence of image retention.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: November 18, 2008
    Assignee: Pioneer Corporation
    Inventor: Eishi Mizobata
  • Patent number: 7453477
    Abstract: An improved driving device for a display panel. In the display panel, pixel cells serving as pixels are positioned in a plurality of display lines. The driving device drives the display panel according to pixel data derived from an input image signal. The display lines are divided into a plurality of display line groups, and each group includes a plurality of neighboring display lines. The driving device has a light emission driving circuit. This circuit causes the pixel cells in each of the neighboring display lines in the respective display line groups to emit light at different brightness levels based on weighting values assigned to the display lines. The weighting values are assigned to the display lines such that bias in brightness differences between the pixel cells positioned in neighboring display lines falls within a prescribed range for all neighboring display lines in the display panel.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: November 18, 2008
    Assignee: Pioneer Corporation
    Inventors: Jun Kamiyamaguchi, Masahiro Suzuki, Tetsuya Shigeta, Hirofumi Honda, Tetsuro Nagakubo
  • Publication number: 20080278417
    Abstract: A AC type plasma display apparatus has been disclosed, which satisfies various requirements such as the number of gradations that can be displayed, the display luminance, and the upper limit of power and, further, the efficiency of light emission and the luminance can be increased as much as possible and the display quality of which is not deteriorated. In the plasma display apparatus, a frame is composed of plural subfields, an image is displayed by causing a sustain discharge to occur in each subfield, the sustain discharge can be caused to occur by at least a first sustain waveform and a second sustain waveform different from the first sustain waveform, and the ratio of the first sustain waveform to the second sustain waveform changes, both waveforms being used to cause the sustain discharge to occur in each subfield.
    Type: Application
    Filed: July 17, 2008
    Publication date: November 13, 2008
    Applicant: HITACHI, LTD.
    Inventors: Takashi SASAKI, Yuichiro Kimura, Yasunobu Hashimoto, Keizo Suzuki, Kenichi Yamamoto
  • Publication number: 20080278416
    Abstract: In a PDP apparatus (multiple grayscale display apparatus), an technique for reducing the unevenness of the electric charge states between cells and the background emission by the reset discharge, and also reducing the false outline, therefore, the image quality can be improved, and the drive can be stabilized is provided. In a multiple grayscale display method by sub field method, a structure in which as a sub field lighting pattern, in only specified sub fields (example: SF3, SF9), light-off sub fields in halfway of continuous light-on sub fields are permitted, is employed. Thereby, the unevenness of the electric charge states between cells is reduced and omission of reset discharge becomes easy, since the number of light-off in halfway is small, the false outlines is reduced.
    Type: Application
    Filed: June 15, 2007
    Publication date: November 13, 2008
    Inventors: Shunji Ohta, Shinsuke Tanaka, Yuichiro Kimura
  • Patent number: 7450090
    Abstract: A plasma display panel and an imaging device realize a high luminous efficiency, a long lifetime and stable driving. The plasma display panel uses a discharge-gas mixture containing at least Xe, Ne and He. A Xe proportion of the discharge-gas mixture is in a range of from 2% to 20%, a He proportion of the discharge-gas mixture is in a range of from 15% to 50%, the He proportion is greater than the Xe proportion, and a total pressure of the discharge-gas mixture is in a range of from 400 Torr to 550 Torr. A width of a voltage pulse to be applied to an electrode serving as an address electrode is 2 ?s or less.
    Type: Grant
    Filed: April 4, 2006
    Date of Patent: November 11, 2008
    Assignees: Hitachi, Ltd., Fujitsu Hitachi Plasma Display, Ltd.
    Inventors: Norihiro Uemura, Keizo Suzuki, Hiroshi Kajiyama, Yusuke Yajima, Masayuki Shibata, Yoshimi Kawanami, Koji Ohira, Ikuo Ozaki
  • Patent number: 7450091
    Abstract: The invention discloses an apparatus for increasing the display gray levels. The apparatus includes a signal transformation circuit, an error diffusion circuit, and an operation circuit. According to a first predetermined manner, the signal transformation circuit transforms a set of image signals into a set of transformed signals. The error diffusion circuit receives the set of transformed signals and generates a set of diffused signals according to a judging rule. The operation circuit receives the set of diffused signals and generates a set of output image signals according to a second predetermined manner and a predetermined operational rule.
    Type: Grant
    Filed: April 4, 2005
    Date of Patent: November 11, 2008
    Assignee: Quanta Computer Inc.
    Inventors: Hsu-Pin Kao, Hsu-Chia Kao, Yi-Chia Shan, Yi-Sheng Yu
  • Patent number: 7446735
    Abstract: In a plasma display panel driving method, a final voltage of a falling ramp voltage is reduced to a voltage for firing a discharge at all the discharge cells in a reset period. A difference between a voltage at an address electrode of a discharge cell to be selected and a voltage applied to a scan electrode is established to be greater than a maximum discharge firing voltage in an address period. A voltage greater than a sustain voltage is applied to the scan electrode so as to convert positive wall charges which can be formed on the scan electrode of a discharge cell which is not selected in the address period into negative wall charges.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: November 4, 2008
    Assignee: Samsung SDI Co., Ltd.
    Inventors: Jin-Sung Kim, Woo-Joon Chung, Seung-Hun Chae, Kyoung-Ho Kang
  • Publication number: 20080266213
    Abstract: According to one embodiment, a plasma display device has a plurality of pixels for displaying images during frames using an input video signal, each of the frames being divided into a plurality of sub-fields, each of the sub-fields including a reset period, an address period, and a sustain discharge period, and the images having gray levels according to combined brightness weights of the sub-fields. The plasma display device includes an address power controller for reducing the gray level of a first pixel of the pixels by decreasing a sum of the brightness weights of the sub-fields, and for increasing the gray level of a second pixel of the pixels by increasing a sum of the brightness weights of the sub-fields, the second pixel being adjacent to the first pixel and the gray level of the second pixel being lower than the gray level of the first pixel.
    Type: Application
    Filed: April 28, 2008
    Publication date: October 30, 2008
    Inventor: Do-Wan Kim
  • Patent number: 7443405
    Abstract: A gray-scale representation method for a plasma display panel, which method includes arranging, in time sequence, a plurality of subfields each having a brightness weight and achieving gray-scale representation by a combination of the subfields, each subfield including an address period and a sustain period. In the gray-scale representation method, the number of sustain pulses for each subfield is determined so that a light generated from the difference of the number of sustain pulses between two adjacent gray scales can be greater than a light discharged in the address period, when the number of subfields for the higher one of the two adjacent gray scales is less than that for the lower one. The reversion of gray scales that occurs when the address light is increased as high as the sustain light can be eliminated to achieve correct gray-scale representation.
    Type: Grant
    Filed: March 12, 2004
    Date of Patent: October 28, 2008
    Assignee: Samsung SDI Co., Ltd.
    Inventor: Yong-Jin Kim
  • Patent number: 7443365
    Abstract: The combination patterns of emissions and non-emissions from the n-th sub-field to the m-th sub-field (where m and n are integers smaller than the total number of sub-fields, and m is greater than n) for a first pixel, a second pixel, a third pixel, and a fourth pixel that are vertically and horizontally adjacent in each of the areas in a display panel are different from one another. Among the first pixel to the fourth pixel vertically and horizontally adjacent in each area of the display panel, the grayscale value displayed by each of the first pixel and the second pixel arranged in one diagonal positions is lower than the average of the grayscale values displayed by the first pixel to the fourth pixel, while the grayscale value displayed by each of the third pixel and the fourth pixel arranged in the other diagonal positions is higher than the average of the grayscale values displayed by the first pixel to the fourth pixel.
    Type: Grant
    Filed: December 26, 2003
    Date of Patent: October 28, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Haruko Terai, Hideaki Kawamura, Junta Asano, Mitsuhiro Kasahara
  • Patent number: 7439941
    Abstract: A display apparatus, which displays a color image by controlling the number of emissions or the intensity thereof in accordance with primary color video signals input thereto, has a detection portion and a white balance correction portion. The detection portion is used to detect the number of emissions or the intensity, and the white balance correction portion is used to correct white balance by adjusting the amplitudes of the primary color video signals in accordance with the detected number of emissions or the detected intensity. Therefore, correct white balance can be maintained regardless of the number of emissions or the intensity of emission.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: October 21, 2008
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Ken Kumakura, Hideaki Ohki, Yuichiro Kimura, Yasuji Noguchi, Takayuki Ooe
  • Patent number: 7439984
    Abstract: An image signal processing method for performing nonlinear compensation on an image signal to be fed into a display device (103). The characteristics of nonlinear compensation are changed according to the brightness of a place in which the display device (103) is installed. This method can make the characteristics of brightness of human beings feel linear with respect to an image signal, even when the display luminance of the display device (103) is uniformly increased by the influence of ambient light.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: October 21, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Kazuhiro Yamada
  • Publication number: 20080252562
    Abstract: A method for driving a plasma display panel including discharge cells at the intersections of data electrodes D1 to Dm and pairs of scan electrodes SC1 to SCn and sustain electrodes SU1 to SUn. One field period is composed of a plurality of subfields each including a wrting period and a sustain period. During the wrting period, a wrting discharge is generated in a selected one of the discharge cells. During the sustain period, a sustain discharge is generated in the selected discharge cell. The voltage to be applied to sustain electrodes SU1 to SUn in the wrting period of the subfield having the lowest display luminance of all the subfields is set higher than the voltage to be applied to sustain electrodes SU1 to SUn in the wrting period of the subfields other than the subfield having the lowest display luminance.
    Type: Application
    Filed: July 14, 2006
    Publication date: October 16, 2008
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Hidehiko Shoji, Takahiko Origuchi
  • Publication number: 20080252563
    Abstract: A method of driving a plasma display panel, which includes secondary electron emission material in a fluorescent layer in discharge cells, has a resetting process in which a first reset discharge is generated between one of a pair of row electrodes of the plasma display panel as an anode and a column electrode as a cathode by applying a voltage between the one row electrode and the column electrode. A second reset discharge is generated by applying a first base pulse having a positive peak potential to the other of the row electrodes while applying a negative potential to the one row electrode. A second base pulse having a positive peak potential different from the positive peak potential of the first base pulse is applied to the other row electrode while a negative potential is applied to the one row electrode throughout the execution period of an addressing process.
    Type: Application
    Filed: March 5, 2008
    Publication date: October 16, 2008
    Applicant: Pioneer Corporation
    Inventor: Shunsuke ITAKURA
  • Publication number: 20080252666
    Abstract: A display apparatus and a method for adjusting brightness thereof are provided. The display apparatus includes a panel unit which displays a video signal, a light emitting unit which provides the panel unit with a ray of light and causes the video signal to be visualized, a light emission control unit which controls the light emitting unit so that the ray of light is provided to each of local areas of the panel unit, and a panel control unit which compensates pixels of the video signal in each of local areas, to remove an artifact which is generated due to the ray of light provided to local areas of the panel unit. Because brightness of a screen is adjusted in each of local areas, contrast ratio is enhanced, and improved image quality is provided.
    Type: Application
    Filed: January 18, 2008
    Publication date: October 16, 2008
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Han Feng CHEN, Yung-jun PARK, Jun-ho SUNG, Hoon CHOI, Jun-ho JUNG
  • Patent number: 7436374
    Abstract: In a Plasma Display Panel (PDP) power control apparatus, an internal voltage of a power supply is detected, and a determination is made as to whether an Alternating Current (AC) power input to the power supply has been turned off on the basis of the detected internal voltage. The output of the power supply is controlled according to a predetermined sequence based on a result of the determination to turn off the PDP. The apparatus rapidly and accurately senses that the AC power has been turned off and performs a predetermined power off sequence to prevent damage to a driving circuit and to prevent the picture quality of the PDP from being degraded.
    Type: Grant
    Filed: October 7, 2004
    Date of Patent: October 14, 2008
    Assignee: Samsung SDI Co., Ltd.
    Inventor: Yong-Seok Chi
  • Patent number: 7432881
    Abstract: An image display apparatus for displaying gray-scale images by writing display information to an image display area of a panel. The display information includes values of a plurality of sub-fields that constitute one field. The image display apparatus converts an input image signal into a piece of display information so that a difference between sub-fields in correspondence with each other in adjacent high gray-scale levels becomes less. The image display apparatus displays a gray-scale image in accordance with the piece of display information.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: October 7, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Isao Kawahaea, Kunio Sekimoto
  • Publication number: 20080238824
    Abstract: When a discharge start voltage takes a normal value under the normal temperature, priming discharge starts at a time t1. In this case, at a time t3 that is later than the time t1 by a predetermined time t, a sustain driver control signal Ssud2 is raised to put a sustain electrode into the floating state to stop the priming discharge. When the discharge start voltage takes a higher value than usual under the high temperature, the priming discharge starts at a time t2. In this case, at a time t4 that is later than the time t2 by the predetermined time t, the sustain driver control signal Ssud2 is lowered to put the sustain electrode into the floating state to stop the priming discharge. With such a configuration, provided is a plasma display device capable of implementing excellent and stable display quality while maintaining constant, even if a discharge start voltage varies, the charge state in display cells after a priming period, and a drive method for such a plasma display device.
    Type: Application
    Filed: May 28, 2008
    Publication date: October 2, 2008
    Inventors: Shinya TSUCHIDA, Shinji Hirakawa, Mitsuhiro Ishizuka, Koji Hashimoto, Hajime Homma
  • Patent number: 7429968
    Abstract: The present invention provides a technique of a method for driving an image displaying apparatus to suppress animated picture pseudo-contour, flicker disturbance and pseudo-contour disturbance by making weighting of light emission within a field is made equal to or almost equal to each other at all gradations. According to this technique, when an image signal of multiple gradation is expressed by dividing one field duration into a plurality of subfields with different relative ratios of luminance, a given number of subfields among a plurality of subfields are divided into “2n” subfields (SF1a to SF8b) wherein “n” represents an arbitrary integral number. Then, “2n” subfield groups (SF1a to SF8a, SF1b to SF8b) are formed so that one group divided into “2n” subfield belong to the groups different from each other. Subfield groups (A and B) are symmetrically arranged with respect to the center of one field duration, and the subfields (SFna, SFnb) divided into “2n” subfields are symmetrically arranged.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: September 30, 2008
    Assignee: Victor Company of Japan Ltd.
    Inventors: Hideki Aiba, Yutaka Ochi, Shigeo Shimizu
  • Publication number: 20080231554
    Abstract: An electroluminescent display comprises a substrate with a plurality of pixel regions, wherein each pixel region has a first sub-pixel region, a second sub-pixel region, and a third sub-pixel region. Pluralities of first color light-emitting layers, second color light-emitting layers, and third color light-emitting layers are formed on the substrate. Each first color light-emitting layer is disposed in one first sub-pixel region, and each second color light-emitting layer is disposed in two adjacent second sub-pixel regions. The area of the first sub-pixel region is larger than the area of the second sub-pixel region in a single pixel region.
    Type: Application
    Filed: July 17, 2007
    Publication date: September 25, 2008
    Inventor: Chung-Chun Lee
  • Patent number: 7427969
    Abstract: A high quality, three-electrode type plasma display apparatus, of which the display of low-luminance gradations has been improved by reducing the minimum luminance of the subfield, has been disclosed. In the plasma display apparatus, a subfield of even lower luminance is provided by: providing at least one subfield made up of only a reset period and an address period, without a sustain period, in one frame, and causing an address discharge to occur only between Y (second) electrodes and address (third) electrodes; or providing at least two second subfields made up of only a reset period and an address period in one frame, and making the intensity of an address discharge differ between the two second subfields.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: September 23, 2008
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Takashi Sasaki, Yuichiro Kimura, Satoru Nishimura
  • Patent number: 7425935
    Abstract: An apparagraph and method of driving a plasma display panel that enables the display of an image wherein contour noise is minimized and that prevents flickering mal-discharge and mis-discharge when the plasma display panel is being driven at high/low temperature is provided. The method includes detecting a drive temperature of a panel, mapping data using a first sub-field pattern mapping when the panel is driven at a low temperature or a high temperature, and mapping the data using a second sub-field pattern mapping different from the first sub-field pattern mapping when the panel is driven at a temperature between the low temperature and the high temperature.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: September 16, 2008
    Assignee: LG Electronics, Inc.
    Inventors: Young Dae Kim, Soo Seok Sim
  • Patent number: 7425936
    Abstract: A driving apparatus for plasma display panel and a gray level expressing method thereof that reduces pseudo-contour. A row average gray level value is calculated through simulation after displaying a test image with different gray levels, and the respective gray levels are classified into a plurality of gray level groups according to the probability of pseudo-contour. The gray level conversion is performed differently according to the plural gray level groups. The gray level values of two frames input consecutively and the illuminating patterns of the subfields are compared to detect the pseudo-contour, and the detecting result is applied to the gray level groups to perform the different gray level conversions.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: September 16, 2008
    Assignee: Samsung SDI Co., Ltd.
    Inventor: Seung-Ho Park
  • Publication number: 20080218447
    Abstract: Luminance of a plasma display is enhanced while suppressing deterioration in resolution. In a plasma display module comprising panel sections (12, 18) and a circuit section (27) and performing display by receiving an interlace signal, two horizontal lines adjacent vertically in each of odd field and even field form a set, two vertically adjacent cells belonging to a set of two horizontal lines display one pixel, each field consists of a plurality of subframes, and two cells in the set are lighted or unlighted simultaneously in a certain subframe at least for some display load rate wherein the ratio of emission intensity is different from 1 when the two cells are lighted simultaneously.
    Type: Application
    Filed: July 6, 2005
    Publication date: September 11, 2008
    Inventors: Yasunobu Hashimoto, Masaji Ishigaki, Masayuki Shibata, Tomokatsu Kishi
  • Patent number: 7423616
    Abstract: A method of driving a plasma display panel including discharge cells, each at an intersection of a scan electrode and a sustain electrode, and a data electrode. One field period is divided into a plurality of sub-fields, each having an initializing period, writing period, and sustaining period. The sustaining period of at least one sub-field has a first sustaining period and a second sustaining period. In the first sustaining period, a transition period of a sustain pulse applied to the scan electrode is not temporally overlapped with a transition period of a sustain pulse applied to the sustain electrode. In a second sustaining period, a transition period of the sustain pulse applied to the scan electrode is temporally overlapped with a transition period of the sustain pulse applied to the sustain electrode. The second sustaining period is included at least at the end of the sustaining period.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: September 9, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kenji Ogawa, Shigeo Kigo, Kenji Sasaki
  • Publication number: 20080211741
    Abstract: A drive method of a plasma display panel that can increase the dark contrast, without causing a discharge failure. When a discharge cell that assumes a black display state in a first field from among first and a second fields that are adjacent in time and switches to a display state representing a brightness other than black in the second field is detected as a lighting transition cell, at least one drive of the below-described first and second forced lighting drives is executed. In the first forced lighting drive, the lighting transition cell is forcibly set into the lighting mode only in the address process of a predetermined subfield within the field in the first field. In the second forced lighting drive, an adjacent discharge cell that is adjacent to the lighting transition cell is forcibly set into the lighting mode only in the address process of the predetermined subfield in the second field.
    Type: Application
    Filed: February 29, 2008
    Publication date: September 4, 2008
    Applicant: PIONEER CORPORATION
    Inventors: Shunsuke ITAKURA, Mitsuhiro ISHIZUKA, Kazuo YAHAGI, Tetsuya SHIGETA, Hirofumi HONDA
  • Patent number: 7418152
    Abstract: An Image correction device for detecting an image area having movement according to an image signal, and providing the image signal with image correction and switching correction methods according to a control signal. The image correction device further detects the boundary area of the image area having movement; detects an image area with great gradational change by comparing gradation of image signals corresponding to adjoining pixels; and provides the boundary area of the image area having movement with a diffusion process in an area excluding the image area with great gradational change. The correcting methods performed by the image correcting device can be switched according to the movement signal, thereby improving image correction.
    Type: Grant
    Filed: February 17, 2005
    Date of Patent: August 26, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Isao Kawahara
  • Patent number: 7417604
    Abstract: A method and an apparatus for driving a plasma display panel with improved image quality are provided. The method for driving a PDP includes: determining whether a frame period is varied on the basis of order of an inputted vertical synchronization signal; varying the frame period; and shifting and arranging the first and second frames in the varied frame period.
    Type: Grant
    Filed: April 16, 2004
    Date of Patent: August 26, 2008
    Assignee: LG Electronics Inc.
    Inventor: Dai Hyun Kim
  • Patent number: 7417610
    Abstract: Provided are image display apparatus and image display methods capable of suitably making correction for variation of driving conditions due to an electric resistance of matrix wiring of a display panel by downsized hardware. The apparatus and methods involve a device of calculating voltage drop amounts caused by the resistance of row wires, for input image data, and a device of calculating image data with correction for the voltage drop amounts (corrected image data). An overflow processing circuit is provided so as to prevent overflow of the image data after the correction from an input range of a modulator, and the overflow is prevented by a gain. Since a gradation converter for changing a gradation conversion characteristic by a gain is provided in the stage preceding to the configuration for making the correction for influence of the voltage drop, it becomes feasible to cancel saturation characteristics of phosphors and to display images with high quality thereby.
    Type: Grant
    Filed: August 29, 2005
    Date of Patent: August 26, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Naoto Abe, Kohei Inamura, Osamu Sagano, Hiroshi Saito, Takeshi Ikeda
  • Publication number: 20080198101
    Abstract: A plasma display apparatus and a method of driving the same are disclosed. In the method, the number of sustain signals assigned to at least one of a plurality of subfields of a frame is different from the number of sustain signals assigned to the other subfields depending on an average power level (APL) of the frame. The number of sustain signals assigned depending on the APL is additionally adjusted in relation to a maximum gray level of the frame.
    Type: Application
    Filed: February 20, 2008
    Publication date: August 21, 2008
    Inventors: Byungsoo Song, Junghwan Kim, Taeok Ha, Seonghak Moon, Seungchan Baek
  • Patent number: 7414598
    Abstract: Disclosed herein are an apparatus for driving a plasma display panel in which the capability to represent the gray scale can be improved, and method thereof. The apparatus includes an inverse gamma control block for performing an inverse gamma correction process on input data received from the outside by using two or more gamma values, and a select unit for outputting one of two or more output data on which the inverse gamma correction operation is performed, which is outputted from the inverse gamma control block. Therefore, the capability to represent the gray scale can be improved. Furthermore, an error diffusion pattern and pseudo noise can be reduced and the picture quality can be thus improved.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: August 19, 2008
    Assignee: LG Electronics Inc.
    Inventor: Kan Han Lee
  • Patent number: 7414597
    Abstract: A PDP driving circuit for a stable operation of a ramp pulse. A capacitor having a temperature characteristic opposite to a temperature characteristic of a part coupled to a switch that operates as a constant current source for generation of a ramp pulse is arranged in the driving circuit for generating a ramp pulse. The ramp pulse linearly increases or decreases a panel voltage of the PDP with respect to time. Parts having opposite temperature characteristics are coupled in parallel to control variation of a gradient of the ramp pulse so that values of the parts may not be varied depending on the temperature changes. Thus, stable operation of the ramp pulse is obtained.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: August 19, 2008
    Assignee: Samsung SDI Co., Ltd.
    Inventors: Hak-Ki Choi, Sang-Chul Kim, Seung-Pil Mun, Kwang-Ho Jin, Sun-Kyung Ahn
  • Publication number: 20080191972
    Abstract: A plasma display panel (PDP) driving method and a PDP gray-representing method for improving representation performance of low gray scales is disclosed. A voltage rising from a low level voltage to a reset voltage of a reset period of a subsequent subfield is applied to a scan electrode, without having a sustain period, after performing an address operation of the subfield with the minimum weight. The discharge cell selected in the address period of the minimum weight is discharged in an initial part of the gradually rising voltage.
    Type: Application
    Filed: April 10, 2008
    Publication date: August 14, 2008
    Applicant: SAMSUNG SDI CO., LTD.
    Inventors: Jin-Sung Kim, Woo-Joon Chung, Seung-Hun Chae, Jin-Boo Son
  • Patent number: 7411570
    Abstract: One field time period is formed of a plurality of subfields having at least a writing time period and a sustaining time period, of an initialization time period, the writing time period, and the sustaining time period. A display electrode pair is divided into a plurality of blocks. Starting timings of the subfields of the blocks are set to be shifted so that writing timings of two or more blocks of the plurality of blocks do not coincide with each other.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: August 12, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toru Kawase, Tomoki Nakakita
  • Patent number: 7408530
    Abstract: The present invention relates to to an apparatus for driving a plasma display panel in which an image being full of life is represented through expansion of contrast and the gray level can be expanded, and method for driving the same. According to the present invention, since a gray level of an input data is distributed over the whole gray level region, contrast can be expanded. It is therefore possible to display an image being full of life. Furthermore, if the gray level of the input data is expanded over the whole gray level region, contrast is increased. Moreover, when the gray level region is expanded, an error diffusion unit and/or a dithering unit are/is not used.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: August 5, 2008
    Assignee: LG Electronics Inc.
    Inventor: Hee Chan Yang
  • Patent number: 7408531
    Abstract: When a discharge start voltage takes a normal value under the normal temperature, priming discharge starts at a time t1. In this case, at a time t3 that is later than the time t1 by a predetermined time t, a sustain driver control signal Ssud2 is raised to put a sustain electrode into the floating state to stop the priming discharge. When the discharge start voltage takes a higher value than usual under the high temperature, the priming discharge starts at a time t2. In this case, at a time t4 that is later than the time t2 by the predetermined time t, the sustain driver control signal Ssud2 is lowered to put the sustain electrode into the floating state to stop the priming discharge. With such a configuration, provided is a plasma display device capable of implementing excellent and stable display quality while maintaining constant, even if a discharge start voltage varies, the charge state in display cells after a priming period, and a drive method for such a plasma display device.
    Type: Grant
    Filed: April 13, 2005
    Date of Patent: August 5, 2008
    Assignee: Pioneer Corporation
    Inventors: Shinya Tsuchida, Shinji Hirakawa, Mitsuhiro Ishizuka, Koji Hashimoto, Hajime Homma
  • Patent number: 7408532
    Abstract: Scan electrodes are provided separately in addition to sustain electrode pairs generating a sustain discharge. An Address-While-Display drive, in which a scan pulse and a sustain pulse are applied at the same timing, is conducted for each subfield. When scan pulses are applied to the scan electrodes, a wall voltage is generated by a wall charge formed on the dielectric layer located on the scan electrodes. This wall voltage is set higher in the negative voltage direction than the wall voltage generated by a wall charge formed on the dielectric layer located on the sustain electrode pairs. As a result, the display luminance level is increased, increase in the scale of power source circuit can be avoided, and a wide drive margin can be obtained.
    Type: Grant
    Filed: June 8, 2005
    Date of Patent: August 5, 2008
    Assignee: Pioneer Corporation
    Inventor: Eishi Mizobata
  • Patent number: 7405732
    Abstract: A liquid crystal drive device having a differential-type input circuit including a differential amplification stage for receiving a differential signal and a buffer stage for generating an output signal on the basis of an output of the differential amplification stage, the liquid crystal drive device for receiving a signal of display data via the input circuit and outputting a signal for driving a liquid crystal panel on the basis of the display data, wherein a liquid crystal driving voltage VLCD larger than a power supply voltage VCC for logic to be supplied to the operation voltage buffer stage is supplied to the differential amplification stage of the input circuit. A standby function of interrupting an operation current of the differential amplification stage in a period where no display data is received is provided.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: July 29, 2008
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
  • Publication number: 20080174524
    Abstract: The present invention relates to a driving method of a plasma display panel for improving a picture quality. The driving method of a plasma display panel in which an nth frame having a first brightness weighting value and a (n+1)th frame having a brightness weighting value different from the first brightness weighting value are alternatively arranged every vertical synchronous signal to display a certain image, wherein one frame period of the nth frame or the (n+1)th frame is variably set such that a brightness expression period can be identically set at the nth frame and the (n+1)th frame.
    Type: Application
    Filed: September 13, 2007
    Publication date: July 24, 2008
    Inventors: Dai Hyun Kim, Jeong Pil Choi, Kyu Seon Lee
  • Patent number: RE40489
    Abstract: One selection period S and display cycles Td of a number corresponding to a maximum gradation level are allotted in one field, and the display cycle Td is composed of an unselection period U and a reset period R to perform the following control. A row electrode-driving circuit is used to output a selection pulse Ps during the selection period S, output an unselection signal Su during the unselection period U in the display cycle Td, and output a reset pulse Pr during the reset period R. A column electrode-driving circuit is used to output an ON signal during a light emission maintenance period, and output an OFF signal at least at an end timing of the light emission maintenance period, of the period other than the light emission maintenance period. Accordingly, it is possible to effectively reduce the electric power consumption, and it is possible to achieve the high brightness.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: September 9, 2008
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao