Setting Of Reference Value Patents (Class 399/59)
  • Patent number: 6321045
    Abstract: In a control system for xerographic development, an important value to be monitored in real time is the ratio of toner to carrier (T/C) in the developer supply. However, direct measurements of T/C, whether by magnetometer readings of the developer, or densitometer readings of developed test patches, tend to be noisy. To exclude unusual T/C measurements, after every T/C reading, a likely range of change in T/C is calculated. If a subsequent T/C reading is not within this likely range, the reading is substituted with an upper or lower boundary of the calculated likely range.
    Type: Grant
    Filed: September 25, 2000
    Date of Patent: November 20, 2001
    Assignee: Xerox Corporation
    Inventors: Roger W. Budnik, James M. Pacer, Scott L. Kauffman, Richard M. Maier
  • Patent number: 6233411
    Abstract: A distributive pitch skipping method and apparatus for stabilizing productivity in an electrostatographic printing machine. The method and apparatus provide for establishing a first toner concentration (TC) limit at and below which toner image reproduction of the machine stops and the machine dead cycles; establishing a second TC limit, higher than the first TC limit, above which the toner image reproduction rate of the machine is 100% at ST ppm (Standard prints per minute); adding fresh toner into a developer housing of the machine in an attempt to maintain the TC of the developer housing above the second TC limit while running copies having various toner area coverage levels; and establishing at least a third TC limit, between the first TC limit and the second TC limit, above which the toner image reproduction rate is less than 100% at (ST-X1) ppm, and below which the toner image reproduction rate is less than 100% at (ST-X2) ppm, where X1 and X2 are integers, and X2 is greater than X1.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: May 15, 2001
    Assignee: Xerox Corporation
    Inventors: Mark A. Scheuer, Debbie S. Wickham
  • Patent number: 6141509
    Abstract: A toner content control device for an electrophotographic apparatus of the type using a toner and carrier mixture. The control device determines an amount of toner replenishment on the basis of a difference between the toner content of the developer and a reference value, while correcting the reference value in accordance with the condition of a reference pattern formed on a photoconductive element. Although the control device includes a toner content sensor and a pattern density sensor, it omits conventional means for adjusting the toner content sensor. The control device is therefore capable of controlling image density stably with an inexpensive configuration.
    Type: Grant
    Filed: December 15, 1997
    Date of Patent: October 31, 2000
    Assignee: Ricoh Company, Ltd.
    Inventor: Kazunori Karasawa
  • Patent number: 6118953
    Abstract: In an electrostatographic process and apparatus a replenishment device adds toner particles to a development station that includes a developer comprising a mixture of toner particles and carrier particles. A reference parameter that is used in control of aim point of toner concentration in the mixture is set to an initial value until about a midlife of the developer is reached. Once the midlife of the developer is reached there are provided programmed step adjustments in the reference value in accordance with further increases in life of the developer to thereby control replenishment of toner particles so that control of charge to mass of the toner particles in the mixture is provided to reduce a tendency of dusting by the toner particles of the mixture due to age of the developer.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: September 12, 2000
    Assignee: Eastman Kodak Company
    Inventors: David E. Hockey, Dennis E. DeMeyer, Kevin D. Lofftus, Paul L. Nielsen
  • Patent number: 6055388
    Abstract: An image forming apparatus includes an image bearing member, a latent image forming device that forms a latent image on the image bearing member, a developing device that develops latent image on said image bearing member to a toner image with a two-component developer, and a toner density detecting device that detects toner density of the two-component developer in which the toner image is formed and outputted as a visible image onto a transfer member. A control device is provided for agitating the developer for a predetermined time period during an initial setting is performed for the developer, detecting a toner density of said developer after the predetermined agitation, and performing an abnormal process when a result of the detection is out of the predetermined range.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: April 25, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Watanabe, Masaru Tanaka, Haruji Mizuishi, Kenzou Tatsumi, Toshitaka Yamaguchi, Takeo Suda, Hiroshi Yoshinaga, Ken Amemiya, Mayumi Oh-Hori
  • Patent number: 6006050
    Abstract: An image forming apparatus including an image bearing member, a latent image forming device which forms a latent image on the image bearing member, a developing device which develops the latent image using a two-component developer including a toner and a carrier and a toner supplying device which supplies toner into the developing device. A developer agitating device agitates developer in the developing device and a toner-density detecting device detects a toner density of developer in the developing device. A toner-density control device controls the toner density by operating the toner supplying device on the basis of a detected result according to the toner-density detecting device. A memory device stores resultant value of the toner density detected by the toner-density detecting device during image forming operations. The toner-density detecting device detects the toner density in a warm-up operation before starting the image forming operation by the image forming apparatus.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: December 21, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Watanabe, Masaru Tanaka, Haruji Mizuishi, Toshitaka Yamaguchi, Kenzou Tatsumi, Hiroshi Yoshinaga, Takeo Suda, Ken Amemiya, Mayumi Oh-Hori
  • Patent number: 5991558
    Abstract: An image forming apparatus that prepares a toner patch including a predetermined gradation area percentage on an image support to detect a developing concentration. An optical sensor detects reflected light from the background of the image support and reflected light from the toner patch prepared on the image support. The reflected light detected by the optical sensor is then controlled in response to the gradation area percentage of the prepared toner patch.
    Type: Grant
    Filed: March 25, 1998
    Date of Patent: November 23, 1999
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Mariko Emi, Shigeru Tsukada, Satoshi Tomita
  • Patent number: 5973795
    Abstract: A toner mark which is to be sensed by a toner concentration sensor in an electrophotographic printing apparatus includes a rectangular dot pattern where a plurality of toner dot patterns are spaced in a staggered configuration. Each of the toner dot patterns is formed in line which is angled with respect to a width direction of the toner mark. Further, any line along a width direction of the toner mark crosses at least one toner dot pattern.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: October 26, 1999
    Assignee: NEC Corporation
    Inventor: Tetsuya Iida
  • Patent number: 5946524
    Abstract: A test pattern image is formed on a photosensitive drum, and the density of the test pattern image is detected by a sensor. The grid voltage Vg of an electrifying charger and the toner concentration T/C in a developer are adjusted according to the detection result so that a target image density can be obtained. Every time a specified number of copies are made in a multiple copying operation, the adjusting target value of the toner concentration T/C is lowered by one step, and the adjusting target value of the grid voltage Vg is heightened by one step.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: August 31, 1999
    Assignee: Minolta Co., Ltd.
    Inventor: Toshihide Taniguchi
  • Patent number: 5920748
    Abstract: An image forming apparatus, such as an electrophotographic copier, forms a test image on a photosensitive member, under constant image forming conditions, and the amount of toner adhering to the photosensitive member is detected. The detected amount of toner is converted into a developer toner concentration, based on a conversion standard. The toner concentration is used to control the operation of a toner replenishment device. The conversion standard is periodically corrected by forming a test image using a developer having a known toner concentration, detecting the amount of adhered toner, comparing the detected result to a standard value, and selecting one conversion standard table from among a number of different conversion tables.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: July 6, 1999
    Assignee: Minolta Co., Ltd.
    Inventors: Atsushi Kawai, Masaki Tanaka, Tetsuya Sakai
  • Patent number: 5826136
    Abstract: CPU is designed to create toner patches on the surface of the photoreceptor drum and pick up the detected data of the density of the toner patches by a photosensor. CPU calculates a correcting value .DELTA.Vg of the charger output in accordance with the picked up detected data, and compared the corrected charger output Vg with (Vgs+.alpha.) and (Vgs-.alpha.). If the corrections in the same direction are repeated in a row, k.beta. (where 0<k<1) is added to or subtracted from the toner density reference value. When the direction of the correction for the toner concentration reference value to be made is opposite that of the previous one, the absolute value of the correcting value for the current correction is set to be the absolute value of the previous one.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: October 20, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hideji Saiko, Motoyuki Itoyama, Jitsuo Masuda, Toshihisa Ishida, Katsuhiro Nagayama, Hiroo Naoi, Masayasu Narimatsu, Tomoko Nishino
  • Patent number: 5787320
    Abstract: A method for adjusting toner density is provided for an image recording apparatus which stores a weighted value table having weighted values corresponding to toner consumption coefficients and a driving table having driving times of a toner supply motor corresponding to the weighted values. The method is carried out by calculating a toner consumption coefficient for each line of a page. This is performed by dividing a number of black data bits represented on each line by a total number of data bits represented on each line. Weighted values corresponding to the calculated toner consumption coefficients are then obtained from the weighted value table. From these weighted values, an average weighted value for the page is generated. The driving table is then searched to locate a driving time corresponding to the average weighted value. The toner supply motor is driven in accordance with the driving time to thereby adjust the toner density while printing the page.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: July 28, 1998
    Assignee: SamSung Electronics Co., Ltd.
    Inventors: Jong-Moon Eun, Yoon-Tae Lee
  • Patent number: 5678132
    Abstract: An image forming apparatus forms a patch image on a recording medium, irradiates the patch image formed on the recording medium with light, and detects a quantity of light reflected by the patch image and outputs a first detection signal. The apparatus detects a quantity of light emitted by a light emission source and outputs a second detection signal, and amplifies the first detection signal in accordance with a first amplification gain and outputs a first amplified signal. The apparatus amplifies the second detection signal in accordance with a second amplification gain and outputs a second amplified signal, and controls image forming conditions based on the first amplified signal or the second amplified signal. An adjustment mode is executed prior to controlling the image forming conditions, and the first amplification gain is controlled when the patch image is formed with black toner, and the second amplification gain is controlled when the patch image is formed with color toner.
    Type: Grant
    Filed: April 25, 1995
    Date of Patent: October 14, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Shiba, Hiroshi Mano, Fumihiro Ueno
  • Patent number: 5667944
    Abstract: A method for producing photographic images from a photographic film strip, of the type that uses density values of the photographic film strip to determine the density values of the produced photographic images, the improvement comprising the steps of:a) forming at least two reference patches of differing exposure conditions onto an otherwise unexposed portion of the photographic film strip prior to photographic processing, each reference patch falling within the total scale of the photographic film strip;b) photographically processing the photographic film strip to form densities corresponding to the photographic images and said reference patches;c) scanning said processed photographic film strip to form density representative digital signals for the photographic images and said reference patches;d) obtaining standard film density values representative of the photographic film strip;e) calculating gamma correction values from said density representative digital signals corresponding to said reference patches
    Type: Grant
    Filed: April 22, 1996
    Date of Patent: September 16, 1997
    Assignee: Eastman Kodak Company
    Inventors: Richard Carroll Reem, James Edward Sutton
  • Patent number: 5649266
    Abstract: A method is described of determining a sensitivity parameter of a toner monitor that forms a part of an electrostatographic recording apparatus having a development station that includes a mixture of a toner material in a toner developer composition wherein concentration of the toner material in the composition tends to change with use of the apparatus in making copies or prints. The method comprises providing in the development station a known weight or concentration of toner material as an initial condition of weight or concentration of toner material. The toner monitor generates a first signal representing a first output voltage of the toner monitor for the initial condition of weight or concentration of toner material. The electrostatographic recording apparatus is operated in a recording mode wherein the predetermined weight or concentration of toner material in the development station is reduced by a predetermined amount.
    Type: Grant
    Filed: April 18, 1996
    Date of Patent: July 15, 1997
    Assignee: Eastman Kodak Company
    Inventor: Allen Joseph Rushing
  • Patent number: 5631728
    Abstract: In an electrophotographic apparatus, an apparatus and method is provided for controlling reproduction by controlling adjustments to the parameters V.sub.o and E.sub.o. A density parameter D.sub.OUT of an exposed and developed maximum density patch is measured. An error, .DELTA.D.sub.OUT, in the measured density parameter is calculated from a density setpoint. The error, .DELTA.D.sub.OUT is multiplied by first and second constants to obtain respective adjustment values used for adjusting E.sub.o and V.sub.o. The control operation is repeated periodically to provide new adjustment values that are used for adjusting E.sub.o and V.sub.o and a fixed ratio is always maintained between the first and second constants.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: May 20, 1997
    Assignee: Eastman Kodak Company
    Inventors: Allen J. Rushing, Matthias H. Regelsberger
  • Patent number: 5623330
    Abstract: In an image forming apparatus, a toner image is formed on an image carrier and the toner image thus formed is transferred onto a transfer material. The image forming apparatus solves troublesome matters of image quality and a transfer material conveying quality due to temperature and/or humidity variations without employing a separate temperature/humidity sensor. The transfer conveying belt includes at least two layers which are, a first layer having a surface resistance rate of 1-10.sup.10 .about.1-10.sup.16 and a second layer having a surface resistance rate of 1-10.sup.7 .about.1-10.sup.11, and the second layer is constructed with a rubber material having a temperature/humidity variation of electric resistance which is larger than a temperature/humidity variation of electric resistance of the first layer. Such a transfer conveying belt itself is then used as a temperature/humidity sensor.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: April 22, 1997
    Assignee: Ricoh Company, Ltd.
    Inventor: Hitoshi Ishibashi
  • Patent number: 5608495
    Abstract: An image density control apparatus which includes a photoreceptor having a photosensitive surface to be uniformly charged to a reference potential and formed with a charge latent image by a reference light amount, a device for developing the charge latent image at a reference developing potential so as to obtain a test pattern, a device for detecting density of the test pattern so as to control image forming condition during an actual image formation according to the detected value. The image density control apparatus further includes a reference condition control device which sets the reference image forming condition for forming the test pattern in accordance with the image forming condition for forming a document which was previously set by detecting a representative density of the document.
    Type: Grant
    Filed: December 30, 1993
    Date of Patent: March 4, 1997
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Hideo Kitakubo, Suguru Hamamichi, Mineo Yamamoto
  • Patent number: 5574543
    Abstract: A patch image is formed on the photoreceptor under a patch image forming condition which is different from a recording image forming condition. The recording image forming condition is controlled by adjusting at least one of a charging device, a developing device and an electric bias in accordance with the density of the patch image.
    Type: Grant
    Filed: September 6, 1994
    Date of Patent: November 12, 1996
    Assignee: Konica Corporation
    Inventors: Eiichi Sakai, Okushi Okuyama