Abstract: A color density measuring step is executed for measuring color densities of unprinted areas on prints. Then, a determining step is executed for determining from the color densities of the unprinted areas on the prints whether ink tinting has occurred. When the determining step determines that ink tinting has occurred, a dampening water adjusting step is executed for adjusting a dampening water feeding rate after feeding dampening water in an increased rate once. A variation in the ink feeding rate is prohibited for a predetermined waiting time after feeding dampening water in the increased rate once in the dampening water adjusting step.

Abstract: A printing apparatus has a manual control mode. The manual control mode has a proportion indication, a proportion adjustment key, a selected range adjustment key, and region selection keys. In the manual control mode, an operator selectively touches the region selection keys to select a region in which an ink key opening is to be changed. Next, the operator touches the selected range adjustment key to change the ink key opening of the selected region. The ink key opening is increased or decreased by the percentage indicated at the proportion indication the number of times the selected range adjustment key is touched. The settings made in the manual control mode are stored in a storage section, and are used to control the amount of ink supply during automatic control. Thus, the printing apparatus having the function of automatically controlling the printed density can make partial tone changes.

Abstract: An ink feeding rate control method for a printing machine includes a step of determining, from image data used in recording images, an average of image area ratios of images in areas on prints corresponding to ink keys, a step of determining, from the image data, an average of image area ratios of images in positions aligned in a printing direction with the detecting patches (i.e. rectangular areas having substantially the same width as the detecting patches and extending in the printing direction) printed in the areas on the prints corresponding to the ink keys, and a step of correcting the reference information based on the average of image area ratios of the images in the areas on the prints corresponding to the ink keys, and the average of image area ratios of the images in the positions aligned in the printing direction with the detecting patches printed on the prints.

Abstract: After an ink feeding rate or a dampening water feeding rate is varied, a variation in the ink feeding rate or dampening water feeding rate is prohibited for a waiting period. The waiting period for prohibiting a variation in the ink feeding rate is determined by a pattern area rate of a corresponding region. The waiting period for prohibiting a variation in the dampening water feeding rate is determined by an average pattern area rate of all regions or a minimum pattern area rate among pattern area rates of all regions. When one of the ink feeding rate and dampening water feeding rate is varied, a variation in the other feeding rate is prohibited for a set period of time.

Abstract: In a first printing process in Steps S1 through S6, ink supply is controlled so that a measured printed density (Vn) is approximately equal to a first target density (V1). This provides a uniform amount of ink remaining on ink rollers after the first printing process. Thereafter, in a second printing process in Steps S7 through S11, printing is performed using a second target density (V2) lower than the first target density (V1). This provides a slightly reduced, uniform amount of ink remaining on the ink rollers. Thus, a novel method of presetting ink is provided which facilitates the formation of a distribution of the new amount of ink at the beginning of the next printing operation and which stabilizes the early start of printing.

Abstract: An ink supply controller capable of generating a proper ink curve from a result of printing even when there is a small difference in image area percentage between ink key regions is provided. The ink supply controller includes an old job data storing element for storing old job data; a new job data acquiring element for acquiring new job data; an ink curve generating element for generating an ink curve based on the old job data and the new job data; an ink curve display element for displaying the generated ink curve; and an updating element for updating the old job data by using the generating ink curve. The ink curve generating element acquires data parameters for generation of the ink curve from both the old job data and the new job data to set an approximate curve obtained from a distribution of these data parameters as a new ink curve.

Abstract: A printing apparatus includes an image reader for reading an image on a printed paper sheet to obtain image data, and a controller for controlling the image reader to obtain image data about a color chart including solid patches once for every predetermined number of printed sheets or at every predetermined time interval which is inputted and set. The controller processes the image data to compute a printed density of each solid patch. Measurement data including the printed density are sequentially stored in a storage section in association with the number of printed sheets or time. The measurement data stored in the storage section may be displayed by a display section or outputted to a print section in the form of history data indicating measurement data transitions. Thus, the printing apparatus including a device for measuring printed sheets can perform history management on the measurement data for every predetermined number of printed sheets or at every predetermined time interval.

Abstract: A color density measuring step is executed for measuring color densities of unprinted areas on prints. Then, a determining step is executed for determining from the color densities of the unprinted areas on the prints whether ink tinting has occurred. When the determining step determines that ink tinting has occurred, a dampening water adjusting step is executed for adjusting a dampening water feeding rate after feeding dampening water in an increased rate once. A variation in the ink feeding rate is prohibited for a predetermined waiting time after feeding dampening water in the increased rate once in the dampening water adjusting step.

Abstract: An ink supply controller capable of generating a proper ink curve from a result of printing even when there is a small difference in image area percentage between ink key regions is provided. The ink supply controller includes an old job data storing element for storing old job data; a new job data acquiring element for acquiring new job data; an ink curve generating element for generating an ink curve based on the old job data and the new job data; an ink curve display element for displaying the generated ink curve; and an updating element for updating the old job data by using the generating ink curve. The ink curve generating element acquires data parameters for generation of the ink curve from both the old job data and the new job data to set an approximate curve obtained from a distribution of these data parameters as a new ink curve.

Abstract: An ink feeding method for a printing machine includes a color density measuring step for measuring color density of prints at intervals of time, a variation coefficient computing step for computing a variation coefficient for varying the ink feeding rate based on the color density of prints and a target color density of prints, a color density gradient computing step for computing, based on the color density of prints, a color density gradient representing a rate of variation in the color density of prints occurring with an increase in the number of prints, an expected color density computing step for computing, based on the color density gradient, an expected color density of prints occurring after a predetermined number of prints are made, a determining step for determining whether the expected color density of prints occurring after the predetermined number of prints are made exceeds the target color density of prints, and a variation coefficient correcting step for correcting the variation coefficient whe

Abstract: After an ink feeding rate or a dampening water feeding rate is varied, a variation in the ink feeding rate or dampening water feeding rate is prohibited for a waiting period. The waiting period for prohibiting a variation in the ink feeding rate is determined by a pattern area rate of a corresponding region. The waiting period for prohibiting a variation in the dampening water feeding rate is determined by an average pattern area rate of all regions or a minimum pattern area rate among pattern area rates of all regions. When one of the ink feeding rate and dampening water feeding rate is varied, a variation in the other feeding rate is prohibited for a set period of time.

Abstract: A communication device that stores a secret key to be used in an authentication and an encryption of communication information with respect to a specific communication device, and carries out communications with the specific communication device, by using the stored secret key to be used with respect to the specific communication device, is equipped with a unit for updating a specific secret key, when an update request received from another communication device is requesting a secret key updating, according to an update content given along with the update request which indicates the specific secret key.

Abstract: A method of feeding dampening water includes a density measuring step for measuring densities of first and second detecting patches 101 and 102 printed adjacent each other on printed matter 100 and presenting a difference in density variations after printing with varied feed rates of damping water and ink, a dampening water feeding step for controlling the feed rate of dampening water based on the densities of the first and second detecting patches 101 and 102 measured in the density measuring step, and an ink feeding step for controlling the feed rate of ink based on the densities of the first and second detecting patches measured in the density measuring step, and the feed rate of dampening water.

Abstract: A printing apparatus has a manual control mode. The manual control mode has a proportion indication, a proportion adjustment key, a selected range adjustment key, and region selection keys. In the manual control mode, an operator selectively touches the region selection keys to select a region in which an ink key opening is to be changed. Next, the operator touches the selected range adjustment key to change the ink key opening of the selected region. The ink key opening is increased or decreased by the percentage indicated at the proportion indication the number of times the selected range adjustment key is touched. The settings made in the manual control mode are stored in a storage section, and are used to control the amount of ink supply during automatic control. Thus, the printing apparatus having the function of automatically controlling the printed density can make partial tone changes.

Abstract: In a first printing process in Steps S1 through S6, ink supply is controlled so that a measured printed density (Vn) is approximately equal to a first target density (V1). This provides a uniform amount of ink remaining on ink rollers after the first printing process. Thereafter, in a second printing process in Steps S7 through S11, printing is performed using a second target density (V2) lower than the first target density (V1). This provides a slightly reduced, uniform amount of ink remaining on the ink rollers. Thus, a novel method of presetting ink is provided which facilitates the formation of a distribution of the new amount of ink at the beginning of the next printing operation and which stabilizes the early start of printing.

Abstract: A printing apparatus includes an image reader for reading an image on a printed paper sheet to obtain image data, and a controller for controlling the image reader to obtain image data about a color chart including solid patches once for every predetermined number of printed sheets or at every predetermined time interval which is inputted and set. The controller processes the image data to compute a printed density of each solid patch. Measurement data including the printed density are sequentially stored in a storage section in association with the number of printed sheets or time. The measurement data stored in the storage section may be displayed by a display section or outputted to a print section in the form of history data indicating measurement data transitions. Thus, the printing apparatus including a device for measuring printed sheets can perform history management on the measurement data for every predetermined number of printed sheets or at every predetermined time interval.

Abstract: In a patch measurement device, a data storage section stores printed-image data including a control strip on a printed material. Based on the pixel values constituting printed-image data stored in the data storage section, a patch position detection section detects the position of a patch. A color density measurement section measures the color density of the patch whose position has been detected by the patch position detection section. A correlation coefficient &rgr;m between a key pattern x and subject data y which is calculated by a reference mark detection section is represented as &rgr;m=([x]*[y])−([x]−1*[y]), where [x]*[y] is a sum of multiplication products of corresponding elements of the two matrices. Matrix [x]−1 represents an inverted pattern of the key pattern x.

Abstract: A method of feeding dampening water includes a density measuring step for measuring densities of first and second detecting patches 101 and 102 printed adjacent each other on printed matter 100 and presenting a difference in density variations after printing with varied feed rates of damping water and ink, a dampening water feeding step for controlling the feed rate of dampening water based on the densities of the first and second detecting patches 101 and 102 measured in the density measuring step, and an ink feeding step for controlling the feed rate of ink based on the densities of the first and second detecting patches measured in the density measuring step, and the feed rate of dampening water.

Abstract: A carbon black producing apparatus comprising a first reaction zone (1) where an oxygen-containing gas and fuel are supplied into the reactor and burned to form a combustion gas flow, a second reaction zone (2) disposed downstream of the first reaction zone and having a feedstock hydrocarbon feed port or ports for supplying a feedstock hydrocarbon to the combustion gas flow, whereby the feedstock hydrocarbon is reacted to produce carbon black, and a third reaction zone (3) disposed downstream of the second reaction zone and designed to stop the reaction, wherein in the first reaction zone, fuel feed port(s) (5) and oxygen-containing gas feed port(s) (6) are provided independently spaced-apart from each other and opened into the reactor from the same side thereof.

Abstract: A carbon black having an average particle size of at most 13 nm, Dmod of at most 80 nm, a D½/Dmod ratio of at most 0.6 and at least pH 5.