Setting Of Reference Value Patents (Class 399/59)
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Patent number: 6321045Abstract: 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: GrantFiled: September 25, 2000Date of Patent: November 20, 2001Assignee: Xerox CorporationInventors: Roger W. Budnik, James M. Pacer, Scott L. Kauffman, Richard M. Maier
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Patent number: 6233411Abstract: 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: GrantFiled: June 7, 2000Date of Patent: May 15, 2001Assignee: Xerox CorporationInventors: Mark A. Scheuer, Debbie S. Wickham
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Patent number: 6141509Abstract: 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: GrantFiled: December 15, 1997Date of Patent: October 31, 2000Assignee: Ricoh Company, Ltd.Inventor: Kazunori Karasawa
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Patent number: 6118953Abstract: 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: GrantFiled: September 18, 1998Date of Patent: September 12, 2000Assignee: Eastman Kodak CompanyInventors: David E. Hockey, Dennis E. DeMeyer, Kevin D. Lofftus, Paul L. Nielsen
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Patent number: 6055388Abstract: 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: GrantFiled: April 3, 1998Date of Patent: April 25, 2000Assignee: Ricoh Company, Ltd.Inventors: Shigeru Watanabe, Masaru Tanaka, Haruji Mizuishi, Kenzou Tatsumi, Toshitaka Yamaguchi, Takeo Suda, Hiroshi Yoshinaga, Ken Amemiya, Mayumi Oh-Hori
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Patent number: 6006050Abstract: 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: GrantFiled: October 30, 1997Date of Patent: December 21, 1999Assignee: Ricoh Company, Ltd.Inventors: Shigeru Watanabe, Masaru Tanaka, Haruji Mizuishi, Toshitaka Yamaguchi, Kenzou Tatsumi, Hiroshi Yoshinaga, Takeo Suda, Ken Amemiya, Mayumi Oh-Hori
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Patent number: 5991558Abstract: 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: GrantFiled: March 25, 1998Date of Patent: November 23, 1999Assignee: Fuji Xerox Co., Ltd.Inventors: Mariko Emi, Shigeru Tsukada, Satoshi Tomita
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Patent number: 5973795Abstract: 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: GrantFiled: February 20, 1998Date of Patent: October 26, 1999Assignee: NEC CorporationInventor: Tetsuya Iida
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Patent number: 5946524Abstract: 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: GrantFiled: December 1, 1998Date of Patent: August 31, 1999Assignee: Minolta Co., Ltd.Inventor: Toshihide Taniguchi
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Patent number: 5920748Abstract: 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: GrantFiled: January 18, 1996Date of Patent: July 6, 1999Assignee: Minolta Co., Ltd.Inventors: Atsushi Kawai, Masaki Tanaka, Tetsuya Sakai
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Patent number: 5826136Abstract: 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: GrantFiled: March 21, 1997Date of Patent: October 20, 1998Assignee: Sharp Kabushiki KaishaInventors: Hideji Saiko, Motoyuki Itoyama, Jitsuo Masuda, Toshihisa Ishida, Katsuhiro Nagayama, Hiroo Naoi, Masayasu Narimatsu, Tomoko Nishino
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Patent number: 5787320Abstract: 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: GrantFiled: August 12, 1996Date of Patent: July 28, 1998Assignee: SamSung Electronics Co., Ltd.Inventors: Jong-Moon Eun, Yoon-Tae Lee
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Patent number: 5678132Abstract: 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: GrantFiled: April 25, 1995Date of Patent: October 14, 1997Assignee: Canon Kabushiki KaishaInventors: Hiroshi Shiba, Hiroshi Mano, Fumihiro Ueno
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Patent number: 5667944Abstract: 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 patchesType: GrantFiled: April 22, 1996Date of Patent: September 16, 1997Assignee: Eastman Kodak CompanyInventors: Richard Carroll Reem, James Edward Sutton
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Patent number: 5649266Abstract: 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: GrantFiled: April 18, 1996Date of Patent: July 15, 1997Assignee: Eastman Kodak CompanyInventor: Allen Joseph Rushing
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Patent number: 5631728Abstract: 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: GrantFiled: January 31, 1996Date of Patent: May 20, 1997Assignee: Eastman Kodak CompanyInventors: Allen J. Rushing, Matthias H. Regelsberger
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Patent number: 5623330Abstract: 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: GrantFiled: April 15, 1996Date of Patent: April 22, 1997Assignee: Ricoh Company, Ltd.Inventor: Hitoshi Ishibashi
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Patent number: 5608495Abstract: 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: GrantFiled: December 30, 1993Date of Patent: March 4, 1997Assignee: Minolta Camera Kabushiki KaishaInventors: Hideo Kitakubo, Suguru Hamamichi, Mineo Yamamoto
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Patent number: 5574543Abstract: 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: GrantFiled: September 6, 1994Date of Patent: November 12, 1996Assignee: Konica CorporationInventors: Eiichi Sakai, Okushi Okuyama