Electrostatic Or Electrolytic Patents (Class 358/300)
  • Patent number: 6125258
    Abstract: An image forming apparatus is provided with a developer for developing a latent image on a photoreceptor drum into a visible image and a transfer drum having a position detector, for holding a supplied transfer material at a predetermined position and conveying the transfer material, and a transfer voltage source for supplying a transfer voltage to a conductive base of the transfer drum and output values of the transfer voltage source vary in stages when toners of a plurality of colors are transferred. In the image forming apparatus, when printing is continuously performed on a plurality of transfer materials, the timing where output values of the transfer voltage source are returned to the initial value is synchronized with the timing where the rear end of a transfer material having a maximum length capable of being printed is separated from the photoreceptor drum. As a result, the transfer material attracted by the transfer drum can be surely prevented from being jammed.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: September 26, 2000
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshinobu Umetani, Hajime Horinaka
  • Patent number: 6111593
    Abstract: A method for achieving multiple exposure levels for IOI (IMAGE-ON-IMAGE) xerography when imaging a second color through a first toner layer previously developed on the photoreceptive member. In the example illustrated the data from the previous image paths (magenta and yellow) is analyzed. If the signal indicates that a magenta or yellow bit is present, the cyan output bit information passes to the ROS unchanged, or at full intensity. If however, the magenta and yellow are not present, a modified pattern providing an appropriate reduced exposure signal is sent to the ROS. The process of laser attenuation is blended with halftoning logic to avoid image degradation due to the attenuation.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: August 29, 2000
    Assignee: Xerox Corporation
    Inventors: Thomas A. Henderson, Peter A. Crean
  • Patent number: 6100907
    Abstract: A multi-beam scanning system has a beam control using an Electrostatic Voltage Sensor or an Image Density Sensor on the Organic Photoconductor. The laser beams can be attuned according to the voltage or density results. This results in a more reliable system as compared to the use of one or more photodetectors.
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: August 8, 2000
    Assignee: Xeikon NV
    Inventor: Bruno Van Uffel
  • Patent number: 6091512
    Abstract: An image processing apparatus for subjecting input image data to a density conversion includes three dot isolation circuits which subject the pixels on each of a plurality of lines adjoining in the sub-scan direction to a density conversion in accordance with a different predetermined conversion characteristic (LUT) for each line. Though each dot separation circuit deals with a different number of lines of image data to undergo a density conversion, the predetermined conversion characteristics can be set in advance in such a manner that the density values of a plurality of pixels on adjoining line will be preserved if an overall view of the reproduced image is taken.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: July 18, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Nobuatsu Sasanuma, Yukio Watanabe, Tetsuya Atsumi, Yuichiro Toyohara
  • Patent number: 6081687
    Abstract: An inverting document feeder feeds a document from the document tray to the position where the image reader reads the document, turns the document over, and then reads the second side. Document size determination sensors detects the document passing through, and determines the size of the document from detections signals of the width of the document and the time elapsed between the detection of the top end of the document and the detection of the bottom end of the document. When the top end of the document reaches the document reading position, image reading is started by a scanner, regardless of whether the document size has been determined or not. The image data thus obtained are written into and read out of a memory unit in a specified order.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: June 27, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Seiichi Munemori, Hirokazu Matsuo
  • Patent number: 6072593
    Abstract: An image data bus changing over section selects a multiple value image data bus at a time of outputting multiple value image data, while the image data bus changing over section selects a binary value image data bus at a time of outputting binary value image data. A synchronization clock changing over circuit puts the synchronization clock in a transmitting state for the multiple value image data, and puts the clock in a stopping state for the binary value image data. When the image data are changed over from the multiple value image data to the binary value image data, the clock is changed over from the transmitting state to the stopping state. When the image data are changed over from the binary value image data to the multiple value image data, the image data bus is changed over from the binary value image data to the multiple value image data.
    Type: Grant
    Filed: April 9, 1998
    Date of Patent: June 6, 2000
    Assignee: Ricoh Company, Ltd.
    Inventor: Masakazu Ooshita
  • Patent number: 6064495
    Abstract: A printing method including:forming a printing bitmap of an image based on a printed solid color density wherein at least one of the colors thereof has a color density substantially greater than the SWOP standard; andprinting the bitmap in a single printing step.
    Type: Grant
    Filed: November 18, 1997
    Date of Patent: May 16, 2000
    Assignee: Indigo N.V.
    Inventor: Benzion Landa
  • Patent number: 6049396
    Abstract: A desktop color copier having a size which allows the copier to be placed on a stand when the copier is used. The desktop color copier includes a photoconductive drum for sequentially forming toner images of respective colors thereon, a charger for charging the photoconductive drum, an exposure device for exposing the charged photoconductive drum, a revolving type developing device for forming color toner images on the photoconductive drum, an image transferring devices which includes an intermediate transfer belt to which the color toner images are sequentially transferred one on top of the other, and a fixing device for fixing the color toner images on a sheet of paper. The desktop color copier includes a single paper feed tray which is located under the transferring devices.
    Type: Grant
    Filed: March 18, 1998
    Date of Patent: April 11, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Susumu Wagi, Kyoji Omi
  • Patent number: 6028616
    Abstract: Xerographic printing system using a Raster Output Scanning (ROS) system incorporating a two wavelength (.lambda.) laser diode source for the ROS and a charge retentive member in the form of a belt or drum structure which is responsive to the two wavelengths. The printing system utilizes a CAD development system in addition to two DAD developments during the second pass for enabling the addition of a gamut broadening color resulting in process color imaging with an enhanced gamut.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: February 22, 2000
    Assignee: Xerox Corporation
    Inventors: Gregory J. Kovacs, Delmer G. Parker
  • Patent number: 6014528
    Abstract: An image forming apparatus capable of simultaneously performing an image forming operation of a first job and an image reading operation of a second job wherein the jobs comprise a plurality of sheets. The apparatus has a controller which continues the image reading operation of the second job even when the image forming operation of the first job is stopped, and prohibits the start of an image reading operation of a third job different from said first and second job when the image reading operation of said second job ends.
    Type: Grant
    Filed: October 9, 1997
    Date of Patent: January 11, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Junko Natsume, Kazuo Inui, Hiroshi Yamada
  • Patent number: 5982129
    Abstract: A method and apparatus for controlling an insertion device includes the steps of providing sensors for providing respective signals in accordance with selected events associated with the operations and providing a plurality of motor profiles for operation of motors associated with the operations. Respective motors associated with respective operations of the apparatus are driven in correspondence with selected ones of said plurality of motor profiles for controlling driving of said motors in response to receiving the event signals from the sensors and other modules of the control program. In the event of out of tolerance conditions the envelope can be diverted and another substituted without having to shut down and restart the system at a known place.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: November 9, 1999
    Assignee: Pitney Bowes Inc.
    Inventors: Eric A Belec, Mary-Jo F. Brigante, Cheryl L. Picoult, William J. Wright
  • Patent number: 5930002
    Abstract: An image forming apparatus comprises a photoreceptor drum, a supporting member provided inside the photoreceptor drum and supporting plural exposure devices; and a signal passage to transmit an image signal to the plural exposure devices. The signal passage connects the outside and the inside of the photoreceptor drum by passing a part of the supporting member.
    Type: Grant
    Filed: May 13, 1997
    Date of Patent: July 27, 1999
    Assignee: Konica Corporation
    Inventors: Satoshi Haneda, Hisayoshi Nagase, Hiroyuki Tokimatsu, Masahiro Onodera, Shuta Hamada, Toshihide Miura
  • Patent number: 5889544
    Abstract: Electrographic printing apparatus for forming a toner image on a recording medium, includes: a magnetic brush having a rotatable magnetic core and a stationary outer shell; a developer supply for supplying a magnetic developer powder including toner to the magnetic brush. A print head on the outer shell forms a plurality of parallel lines of developer. Toner is selectively transferred from a plurality of electrodes within each line to a receiver. A receiver electrode is arranged in spaced relation to the print head to define a recording region through which the receiver can be moved.
    Type: Grant
    Filed: April 10, 1997
    Date of Patent: March 30, 1999
    Assignee: Eastman Kodak Company
    Inventors: William Mey, Thomas N. Tombs, Thomas M. Stephany, William J. Grande
  • Patent number: 5870648
    Abstract: An electrographic recording apparatus having a memory for storing first and second images having different sizes and using an intermediate transfer member compares sizes of the input images of first page and second page with a size of a transfer area of the intermediate transfer member, and when a sum of the sizes of the images of the first page and the second page is less than the size of the transfer area, controls image forming means to transfer developed images of the first page and the second page to the intermediate transfer member in one process to reduce a time required for recording in a multiple sheet image recording mode.
    Type: Grant
    Filed: December 8, 1995
    Date of Patent: February 9, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Eihiro Sakaki, Tohru Kosaka
  • Patent number: 5859711
    Abstract: A multiple print engine configuration allows a plurality of workstations (10) to create individual print jobs and then transfer them to a distributing processor (14). The distributing processor (14) is operable to spool the jobs in a print spooler (20) and then perform a software RIP on the print jobs. The RIP process divides the jobs into multiple individual jobs which are stored in the page buffer (24). An image task manager (26) in conjunction with an engine manager (28) are then operable to selectively distribute the pages to multiple print engines (16). They are distributed in such a manner that they are placed in the output bins (40) in the order that the pages were received in the print jobs.
    Type: Grant
    Filed: August 16, 1996
    Date of Patent: January 12, 1999
    Assignee: T/R Systems, Inc.
    Inventors: Michael W. Barry, Jack N. Bartholmae, Francis A. Rowe, E. Neal Tompkins, Peter A. Zuber
  • Patent number: 5856876
    Abstract: This invention has as its object to provide an image processing apparatus and method, which can obtain high image quality by adjusting an image forming parameter or parameters in consideration of a variation in image forming condition. In order to achieve the object, the gradation characteristics of an image to be recorded are adjusted on the basis of information obtained by forming a gradation characteristic adjustment test pattern on a recording medium, and reading the formed test pattern. Subsequently, the color reproduction characteristics of an image to be recorded are adjusted on the basis of information obtained by forming a color reproduction characteristic adjustment test pattern on a recording medium, and reading the formed test pattern.
    Type: Grant
    Filed: April 5, 1996
    Date of Patent: January 5, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Nobuatsu Sasanuma, Kazuhito Ohashi, Masahiro Inoue, Yuichi Ikeda
  • Patent number: 5838456
    Abstract: A desktop color copier having a size which allows the copier to be placed on a stand when the copier is used. The desktop color copier includes a photoconductive drum for sequentially forming toner images of respective colors thereon, a charger for charging the photoconductive drum, an exposure device for exposing the charged photoconductive drum, a revolving type developing device for forming color toner images on the photoconductive drum, an image transferring devices which includes an intermediate transfer belt to which the color toner images are sequentially transferred one on top of the other, and a fixing device for fixing the color toner images on a sheet of paper. The desktop color copier includes a single paper feed tray which is located under the transferring devices.
    Type: Grant
    Filed: January 2, 1996
    Date of Patent: November 17, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Susumu Wagi, Kyoji Omi
  • Patent number: 5835686
    Abstract: A method and apparatus for an electronic prepress system includes a computer workstation for preparing electronic image files. The computer workstation transfers the image files to an image processor that converts the image files into digital data. The digital data is then transferred to a virtual-drum capstan-driven output device for outputting the image files onto paper, film or plate material. The output device has increased output speed and reduced cost compared to an internal drum device. A capstan drive moves web type image recording media through a curved media platen having an upper curved surface and a lower curved surface which form the media into a virtual drum. The optical system has a rotating reflective spinner at the center of curvature of the virtual drum to scan modulated image date across media while being continuously driven.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: November 10, 1998
    Assignee: Agfa Division--Bayer Corporation
    Inventor: Arthur J. Bellemore
  • Patent number: 5835233
    Abstract: A picture forming apparatus comprises a memory means for storing an inputted picture data, a picture data changing means for changing a stored data into a new picture data in order to save a recording material, and a picture printing means. The picture data changing means changes the stored picture data into a new picture data in order to save a recording material only when a saving command of a recording material is given. The new picture data includes smaller dots than the stored picture data and/or has a fewer picture dots than the stored picture dots. As a result, the new picture data enables the picture printing means to save a recording material.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: November 10, 1998
    Assignee: Matsushita Electric Industrial Co., Ltc.
    Inventors: Kazunori Otsu, Takashi Kitada, Hiroyuki Yamada, Muneo Unoki, Koichiro Tsuruno
  • Patent number: 5831744
    Abstract: An image forming apparatus has an image forming unit for forming an image on a recording member, an inputting device for manually inputting information regarding the recording member, a control for controlling image forming conditions on the basis of the input value by the inputting device, a detector for detecting the thickness of the recording member, and a warning unit for warning of the abnormality of the input to the inputting device on the basis of the input value by the inputting device and the detection value of the detector.
    Type: Grant
    Filed: July 17, 1996
    Date of Patent: November 3, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tatsuhito Kataoka
  • Patent number: 5825504
    Abstract: A method is provided for reproducing a continuous tone image by imagewise application of toner particles to a substrate comprising the following steps:partitioning a surface of the substrate in a plurality of disjunctive microdots;applying to at least one microdot at least two types of toner, having substantially the same chromaticity.Preferentially, for each toner type a large majority of microdots within a region comprising adjacent microdots, is supplied with either a high or low amount of toner, whereas the other microdots are supplied with a medium amount of toner, and more preferentially for at least one toner type the region comprises at least one microdot supplied with a high, another with a low and another with a medium amount of said toner.In a preferred embodiment the minimum number (N) of types of toner particles used in the method of this invention depends on the volume average size of the toner particles used.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: October 20, 1998
    Assignee: AGFA Gevaert
    Inventors: Dirk Broddin, Serge Tavernier
  • Patent number: 5826133
    Abstract: An image reading apparatus includes a stacking unit for stacking a plurality of originals, a separating unit for sequentially separating the original in the bottom portion among the originals on the stacking unit, a conveying unit for conveying the original which was sequentially separated by the separating unit along a conveying path, a first reading unit for reading the original surface which faces up when it is stacked onto the stacking unit when the original passes through the conveying path, a second reading unit for reading the original surface which faces down when it is stacked onto the stacking unit when the original passes through the conveying path, and a control unit for controlling the first and second reading units in accordance with a copy mode and a facsimile transmission mode, wherein the control unit allows the first reading unit to read the original in the copy mode and allows the second reading unit to read the original in the facsimile transmission mode.
    Type: Grant
    Filed: February 21, 1996
    Date of Patent: October 20, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaaki Saito, Koji Takahashi, Masahiko Yokota
  • Patent number: 5822079
    Abstract: An image forming apparatus is provided which is immune to characteristic variations of a photoconductor and a developer material, which can detect the amount of toner adhering to a test toner image accurately, and which can always form a favorable image using an optimal image forming parameter. A predetermined test toner image is formed on the photoconductor using developing devices. The amount of toner adhering to the formed test toner image is detected by an AIDC sensor. A printer control unit determines grid potential Vg of a corona charger and development bias potential Vb of each developing device based on the detected amount of adhering toner. A predetermined image is formed using the determined grid potential and development bias potential.
    Type: Grant
    Filed: March 6, 1996
    Date of Patent: October 13, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Yukihiko Okuno, Toshifumi Watanabe, Kentaro Katori
  • Patent number: 5818488
    Abstract: Bit data of a received video signal is partially converted into a first signal representing a data sequence corresponding to the resolution of an LED head. The remaining bit data of the received video signal, which are not converted into the first signal are converted into a second signal representing another data sequence corresponding to the resolution of an LED head. The LED head includes a resolution conversion circuit which converts the video data into the first signal and the second signal. The signals are stored in a shift register having a plurality of line buffers. The first signal is printed on a basic raster line and the second signal is printed on an additional raster line. An LED head drive energy with which basic raster lines are printed and another LED head drive energy with which additional raster lines are printed are set independently of each other.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: October 6, 1998
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Jiro Tanuma, Katsuyuki Ito, Shinichi Katakura, Nobuo Wakasugi, Kazuhiko Nagaoka, Toshikazu Ito
  • Patent number: 5805296
    Abstract: An optical scanning apparatus includes a semiconductor laser, a polygonal mirror as a deflector for scanning a light beam from the laser, a photosensitive drum for forming an electrostatic latent image, a converging lens for converging the light beam from the laser onto the photosensitive drum, and a reflection mirror located between the deflector and the photosensitive drum. The reflection mirror is adapted to reflect the light beam so that a light beam reflected by the reflection mirror is used to read a source document placed at a position that is the conjugate of the position of the photosensitive drum surface with respect to the converging device. Inside the casing of the semiconductor laser are a beam splitter for light path separation and a photosensor. The apparatus has an image reader section and a laser printer section, which share a common optical system, thus providing a compact design and cost reduction and also equalizes the accuracy of image reading and printing.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: September 8, 1998
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Yutaka Hattori
  • Patent number: 5805309
    Abstract: An electrophotographic facsimile having a single integrated transmitting and receiving unit includes a photosensitive drum, a charging unit, an exposure unit, a developing unit, a transfer unit, a heating roller, a pressure roller, a latent image erasing lamp, a cleaning blade, an automatic feeding convey roller, a rubber pad, a whiter roller, a contact image sensor, and a pickup roller, in which document transmission, reception and copying operations are implemented by the integrated transmitting and receiving unit.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: September 8, 1998
    Assignee: SamSung Electronics Co., Ltd.
    Inventor: Hyung-Hyu Hwang
  • Patent number: 5802215
    Abstract: A lead edge lightening circuit which will lighten a scan line based on a seven by seven pixel area surrounding the current pixel. The area is divided into four sub-areas, each of four by four pixels, and each having the current pixel at one corner. Each sub-area is summed and compared to a threshold number. If the threshold number is equalled or exceeded by at least one of the four sums, an overlay bit, which can be white or black, is output. The current pixel is replaced by a white pixel if a white pixel has been output, otherwise the current pixel remains unchanged.
    Type: Grant
    Filed: December 17, 1996
    Date of Patent: September 1, 1998
    Assignee: Xerox Corporation
    Inventors: Rosario A. Bracco, George L. Harer, Sue K. Lam, Louis D. Mailloux, Hoan N. Nguyen, Cheryl A. Pence, Hung M. Pham, Cathleen J. Raker, Farhad D. Rostamian, Robert R. Thompson, Jr., Daniel D. Truong
  • Patent number: 5790275
    Abstract: A scanning optical system having both a reading optical system and an image forming optical system is capable of using one or more components for both systems.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: August 4, 1998
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventor: Takashi Iizuka
  • Patent number: 5777751
    Abstract: An output writer includes an output scanner and optics that creates printed pixels along curved scan paths. Provided that a source of input image pixel value data presents data with pixels to be positioned in a rectangular coordinate system with a constant distance in an x-direction between adjacent input pixels, a position is determined along the curved scan paths of a pixel to be printed. The difference between the position of the pixel to be printed and the positions in the rectangular coordinate system of associated input pixels is determined, and then a value for the pixel to be printed is determined as a function of (1) the value data of the associated input pixels and of (2) the determined difference between the position of the pixel to be printed and the positions of the associated input pixels.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: July 7, 1998
    Assignee: Eastman Kodak Company
    Inventor: Joseph Ward
  • Patent number: 5768652
    Abstract: A method of controlling an electrophotographic imaging process wherein a two-component developer is mixed and activated to obtain a uniform distribution and triboelectric charging of the toner, by interruption of the process and carrying out extra activation and mixing cycles as a function of image area coverage and/or distribution of the image over the image field.
    Type: Grant
    Filed: October 22, 1996
    Date of Patent: June 16, 1998
    Assignee: Agfa-Gevaert
    Inventors: Robert Janssens, Luc Van Goethem, Willem Waterschoot, Chris Pattyn
  • Patent number: 5767982
    Abstract: An image forming apparatus using a photosensitive body (1) having high gamma characteristics has an exposure unit that is provided with a radiation element whose exposure value is variably set and which is capable of blinking on a pixel-by-pixel basis. An exposure controller (6) is provided with an exposure pattern determining unit (7) that determines an exposure pattern according to the image pattern, and an exposure value switching unit (8) that switches between an exposure value A1 at which the potential of the photosensitive body (1) sharply attenuates and an exposure value A2 at which the potential of the photosensitive body (1) does not substantially attenuate, on the basis of the exposure pattern determined by the exposure pattern determining unit (7).
    Type: Grant
    Filed: October 17, 1996
    Date of Patent: June 16, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yoshikazu Takahashi, Satoshi Hirota, Yu Tsuda
  • Patent number: 5764377
    Abstract: A raster output scanner data controller reads pixels of an image from an image memory and outputs serially pixel data streams to a raster output scanner. The data controller includes an image memory storing a plurality of pixel data blocks in a scan line order, an image memory controller coupled to the image memory, a plurality of first-in, first-out memories coupled to the image memory controller for storing pixel data blocks corresponding to a plurality of beams, and an image controller coupled to the plurality of first-in, first-out memories. The pixel data blocks are transferred from the image memory to the plurality of first-in, first-out memories. The image controller reads the pixel data blocks from the plurality of first-in, first-out memories, converts the pixel data blocks read from the plurality of first-in, first-out memories into a plurality of pixel data streams and outputs the plurality of pixel data streams to the raster output scanner.
    Type: Grant
    Filed: December 15, 1994
    Date of Patent: June 9, 1998
    Assignee: Xerox Corporation
    Inventors: Aron Nacman, Daniel A. Mohabir
  • Patent number: 5760928
    Abstract: In an image forming apparatus which combines a plurality of different image forming methods, the image forming operations of the plurality of image forming methods are controlled in accordance with the color of an original image and the color of a recording agent, so that image formation in a desired color can be reliably attained, and copying errors can be eliminated. In another aspect, by appropriately selecting the plurality of image forming methods in correspondence with the feature of an image, high-quality image formation can be attained in correspondence with the image feature.
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: June 2, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Eiichi Motoyama, Yasuhiro Yamada
  • Patent number: 5758043
    Abstract: An image processing method and apparatus which divides image information into a plurality of predetermined-sized partial images, and sequentially performs designated image processing by partial image, thus enables image processing of the read image data using a small memory capacity. In the apparatus, an image reader reads image information, in accordance with a designated reading size, and stores the read image data, as partial image data, into an image memory. Then, a designated special-effect image processing is performed on the partial image data stored in the image memory. An image output unit sequentially outputs special-effect image processed partial images.
    Type: Grant
    Filed: September 5, 1995
    Date of Patent: May 26, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masashi Takizawa, Katsumi Masaki, Masayuki Takayama, Hiroshi Netsu, Makoto Nihei, Koji Kawamura
  • Patent number: 5757508
    Abstract: A charging member including an elastomeric member including an elastomeric material. The elastomeric material includes a polymer dispersion medium having a double oxide dispersed therein, the double oxide being a solid solution compound of oxides of at least two different metals formed by crystal lattice substitution. The at least two different metals have different valences, whereby the double oxide has an electroconductivity that is larger than that of either one of the oxides of at least two different metals when not in solution. Also, the charging member has resistance stability in the semiconductive region.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: May 26, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventor: Jun Murata
  • Patent number: 5751437
    Abstract: Full color, single pass and two-pass imaging processes using black, magenta, cyan and yellow toners and Non-interactive Development without fringe field development. Corona discharge is utilized for voltage leveling certain developed images prior to their passage through DAD developer housings. A Raster Output Scanner (ROS) used for creating the latent electrostatic images is also used for voltage leveling of images developed on the first pass of the two pass imaging process in order to remove certain other images for eliminating fringe field images as well as other undesired images.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: May 12, 1998
    Assignee: Xerox Corporation
    Inventors: Delmer G. Parker, Gregory J. Kovacs
  • Patent number: 5751431
    Abstract: A digital image forming apparatus equipped with an optical scanner unit which is detachable from a main body includes an upper image reading section and a lower part image forming section. The apparatus is arranged such that the optical scanner unit can be installed and removed in and from the apparatus in a vertical direction, and can be removed through an opening provided for removing the image forming section therethrough. According to the described arrangement, during the installation and removal of the optical scanner unit, removal of the image reading section and a special opening for the optical scanner unit are not required, thereby reducing the restriction on structural design of the apparatus and permitting easy installation and removal of the optical scanner unit. As a result, the maintenance of the apparatus can be performed with an improved efficiency.
    Type: Grant
    Filed: February 27, 1996
    Date of Patent: May 12, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kyosuke Taka, Keiji Masuda, Kan Mukai
  • Patent number: 5748328
    Abstract: A color image processing apparatus includes arranging means for arranging intervals between dot positions on a scanning line at which dots are formed, and shifting means for shifting the dot positions on the scanning line by a shifting amount. At least one of the intervals and the shifting amount for a first color component are different from an interval and a shifting amount of a second color component. The processing apparatus also includes control means for controlling the arranging means and the shifting means so that n (n.gtoreq.3) adjacent dot positions at which the first color component and the second color component overlap correspond to vertices of a substantially regular polygon having n vertices.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: May 5, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akihiro Usami, Yoshinori Mochida, Atsutomo Yoshizawa, Yoshinori Ikeda, Kazuhisa Kemmochi, Yukio Nagase, Shinobu Arimoto, Masanori Yamada, Hajime Suzuki, Katsuhito Kato
  • Patent number: 5745247
    Abstract: An image forming apparatus for reading a document image, digitizing the resulting image data, and then forming an image on the basis of the digitized image data. The apparatus is selectively operable in an ordinary mode for reading the document image every time an image is formed or in a high-speed mode for writing the digitized image data in a memory so as to form a plurality of images by a single scanning while reducing the interval between consecutive papers. A fixing unit is provided with a higher reload temperature in the high-speed mode than in the ordinary mode. This obviates a cold offset in the event of a start-up when the high-speed mode is selected.
    Type: Grant
    Filed: January 27, 1995
    Date of Patent: April 28, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Motokazu Yasui, Yasuhisa Kato
  • Patent number: 5737004
    Abstract: A method of developing an electrostatic latent image produced on a surface of a movable intermediate carrier by electrically-charged dielectric color particles which are transported through a gap between the surface of the intermediate carrier and a surface of a developing device includes loosely filling most of the gap with color particles, and successively producing, along the transport path of the color particles through the gap, the following voltage differences between the surface of the developing device and non-image regions on the surface of the intermediate carrier: a first voltage difference substantially equal to zero, so that the color particles are not electrostatically attracted or repelled, in substance, by the surface of the developing device and by the non-image regions, respectively; a second voltage difference providing an electric field between the surface of the developing device and the non-image regions, the color particles in the non-image regions being completely separated from the su
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: April 7, 1998
    Assignee: Heidelberger Druckmaschinen AG
    Inventor: Anton Rodi
  • Patent number: 5729352
    Abstract: When a metal strip continuously fed and made of stainless-steel, an aluminum alloy or a nickel alloy is bent followed by welding opposite ends of the metal strip to form a pipe and followed by grinding the pipe, the pipe is subjected to heat treatment after the pipe has been welded and before the pipe is ground. Annealing or normalizing adaptable to the type of the metal is selected as the heat treatment. As a result, work hardening can be relieved by the above processes. Moreover, generation of magnetism attributable to martensitic transformation generated in a portion, in which bending stress is concentrated, can be prevented. Thus, work hardening due to the bending operation during the process for forming the pipe can be relieved so that the following grinding operation is performed accurately. Therefore, generation of partial magnetism due to the bending operation can be prevented so that an excellent image can be formed.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: March 17, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Junichi Shibata, Arimichi Fukuda
  • Patent number: 5729353
    Abstract: In an image forming apparatus, a method of correcting a position for writing an image on a photoconductive element on the basis of a signal representative of a pattern formed on the element and detected, and a device therefor. A single photoconductive element is used to form a plurality of different colored images using a single rotating polygonal mirror and a plurality of light sources. The toner images can be sensed either while they are on the single photoconductive element or by sensing them through a transport belt.
    Type: Grant
    Filed: March 4, 1997
    Date of Patent: March 17, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Noboru Sawayama, Takashi Mama
  • Patent number: 5729626
    Abstract: In a digital image forming apparatus, a document image is read as digital data, and an image type of bi-level image or multi-level image is discriminated from the digital data. For a bi-level image, an intensity of laser beam for exposing a photoconductor is modulated according to the image data with a duty ratio of 100%. On the other hand, for a multi-level image such as a photograph image, the intensity of laser beam is modulated with a duty ratio in the unit of two or more dots according to the image data. The duty ratio and the laser output power are changed according to a type of document image or according to sensitivity characteristic of the photoconductor.
    Type: Grant
    Filed: December 28, 1994
    Date of Patent: March 17, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Yoshinobu Hada, Kazuyuki Fukui, Takanobu Yamada
  • Patent number: 5729270
    Abstract: Toner is conserved in printer (1) under operator control by changing the final modulation for each bit in a bit map depending on whether the bit is an edge bit or an internal bit in the character being printed. Since only the final modulation is affected, processing speed and efficiency are not degraded. The operator can select various degrees of internal gray and internal white. Some levels of gray may be satisfactory for some final correspondence.
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: March 17, 1998
    Assignee: Lexmark International, Inc.
    Inventors: Phillip Byron Wright, Dale Randal Danner, Martin Victor DiGirolamo, Gary Scott Overall, John Parker Richey
  • Patent number: 5726776
    Abstract: The invention relates to a method and to an arrangement for the synchronization of the image recording of monochrome recordings and color recordings with photosensitive line sensors. A line-scanning pattern is generated by a programmable counter arrangement, wherein the timer measures the phase position of the line-scanning pattern, generated by the counter arrangement, with the aid of the computer and the programmable counter arrangement at the point in time of the impinging of a pulse of the incremental transmitter, wherein the timer compares these with a coordinated calculated or tabulated reference value, and wherein the timer employs the thus obtained phase difference in order to influence a counter, preconnected to the line counter CT2, in its count volume (FIGS. 1 and 2).
    Type: Grant
    Filed: February 2, 1996
    Date of Patent: March 10, 1998
    Assignee: F & O Electronic System GmbH
    Inventors: Michael Auer, Hans-Peter Grossmann, Joachim Ihlefeld, Michael Pester, Gunther Uhlig, Lutz Wenert
  • Patent number: 5721622
    Abstract: A method for printing grayscale images that compensates for problems in the printing process. The presence of a defective element on a spatial light modulator (12) is compensated for using a background value. The background value is determined by the number of defective elements stuck in the ON position, and that value is added to all of the exposure values of the elements, creating exposure data. In one embodiment, a defect intensity value is subtracted from those pixel exposure values affected by defective elements. The exposure data is used to generate microimages on a photoreceptive drum, the data is decremented and the steps are repeated until an entire image has been produced.
    Type: Grant
    Filed: January 6, 1997
    Date of Patent: February 24, 1998
    Assignee: Texas Instruments Incorporated
    Inventor: Vadlamannati Venkateswar
  • Patent number: 5719684
    Abstract: In an image forming apparatus having an endless transferring and conveying device for conveying a recording medium and electrostatically transferring a toner image from an image carrier to the medium, the mechanical operation of an image forming section is interrupted throughout the duration of preselected image processing executed by image processing means. As a result, the amount of toner to reach a cleaning section assigned to the endless transferring and conveying means is reduced. This frees the recording medium from contamination ascribable to defective cleaning and thereby insures attractive images.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: February 17, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Ohkaji, Masato Yokoyama, Masumi Sato
  • Patent number: 5719682
    Abstract: A method for printing grayscale images that compensates for problems in the printing process. The presence of a defective element on a spatial light modulator (12) is compensated for with use of a white balancing area. If a column of the modulator (12) has an element stuck ON, a corresponding element in the same column in the white balancing area is turned OFF while all other columns have elements that are ON. If the illumination is non-uniform, the exposure values of each element are multiplied by an efficiency factor which compensates for the non-uniformity.
    Type: Grant
    Filed: January 7, 1997
    Date of Patent: February 17, 1998
    Assignee: Texas Instruments Incorporated
    Inventor: Vadlamannati Venkateswar
  • Patent number: 5715067
    Abstract: In a digital image forming apparatus, when a latent image is formed on a photoconductor, a light from a light source is emitted in a period of a duty ratio while modulated according to image data, and the latent image is developed and transferred onto a sheet of paper. The duty ratio, defined as a ratio of a light-emitting time of a light exposing the photoconductor to a period for exposing a dot, is changed in the same document according to dot information on the document such as an edge signal. In the modulation of the optical intensity, the light emission onto the photoconductor is performed with a duty ratio which may be set for each dot. Image portions formed with different duty ratios may exist at the same time in a reproduced image. For example, an edge portion in a document is reproduced at the duty ratio of 100% while a non-edge portion is reproduced at the duty ratio less than 100%.
    Type: Grant
    Filed: March 4, 1996
    Date of Patent: February 3, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Kentaro Katori, Masahiro Kouzaki, Yoshinobu Hada, Yukihiko Okuno, Katsuyuki Hirata
  • Patent number: 5712711
    Abstract: An image processing system for converting an input pixel into n subpixels P1, P2, . . . , Pn, said system includes a comparator for comparing density threshold values D1, D2, . . . , Dn (where D1<D2<. . . <Dn) corresponding to the subpixels P1, P2, . . . , Pn with a density of the input pixel, Din; and a density setting unit for setting subpixels P1, P2, . . . , Pk corresponding to density threshold values D1, D2, . . . , Dk of the density threshold values D1, D2, . . . , Dn (where k<n) less than the density Din to a high density, setting subpixels Pk+2, . . . , Pn to a low density, and setting subpixel Pk+1 to an intermediate density.
    Type: Grant
    Filed: August 13, 1996
    Date of Patent: January 27, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventor: Yuzuru Suzuki