JP2007076101A - Method and device for setting zero point of ink key - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for setting a zero point of an ink key which makes it possible to set accurately and automatically the zero point of the ink key. <P>SOLUTION: The method is provided for setting the zero point of the ink key in an ink supply arrangement of a printing machine having the ink keys 7 in a plurality and an opening control mechanism 53 which controls the opening of each ink key 7. The method has a detecting step where the start or completion of transfer of ink is detected and a zero point setting step where the zero point of the opening of the ink key is set on the basis of the result of the detection at the detecting step, while the opening of the ink key 7 is controlled by the opening control mechanism 53 for the ink keys 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to ink key opening adjustment provided in a printing press, and relates to an ink key 0 point setting method for accurately and easily setting the 0 point of an ink key opening and an ink key 0 point setting apparatus using the same.

  In a printing press such as a sheet-fed printing press or a rotary printing press, the ink supplied from the ink fountain to the printing cylinder by adjusting the gap amount (called the ink key opening) between the ink key and the ink base roller provided in the ink supply device. The supply amount is adjusted. A plurality of ink keys are arranged in parallel in the printing width direction, and the ink supply amount can be adjusted in units of width of ink keys (referred to as key zones).

  The ink supply amount is larger as the line rate of the printed pattern is larger, and is smaller as the line rate of the printed pattern is smaller, and needs to be set according to each line rate of the printed pattern. Therefore, as shown in FIG. 16, the printing machine stores an API function (ink supply amount conversion function) that defines the relationship between the line drawing rate and the ink key opening, and uses this ink supply amount conversion function. By setting the ink key opening according to the line drawing rate for each key zone, an appropriate amount of ink can be supplied according to the line drawing rate of the printed pattern.

  Ink press opening adjustment in the printing press may be performed while the operator manually operates the ink key adjustment screw while visually observing the density of the print sheet. Ink supply amount automatic setting device that automatically sets the ink key opening Has also been proposed (see, for example, Patent Document 1). In addition, a technique for automatically presetting the opening degree of the ink key corresponding to each key zone based on the print data for each key zone before printing is proposed (see, for example, Patent Document 2).

  Usually, a printing press is equipped with an ink key opening sensor such as a potentiometer to detect the corresponding ink key opening for each ink key. First, the target ink key opening is set for each ink key on the basis of the information about the line rate of the printed pattern such as printing data and the ink supply amount conversion function, and the ink key opening sensor The drive of an actuator such as a motor connected so as to adjust the ink key opening degree is controlled by swinging the ink key so that the ink key opening degree detected by is controlled to the target opening degree.

In the ink supply amount conversion function described above, the zero point of the ink key opening is the maximum opening at which ink is not transferred to the printing sheet during printing (i.e., the ink key opening is slightly larger than this). It can be defined as (the point at which ink is transferred to the printing sheet) (this point is referred to as 0 point).
By the way, the inclination of the ink key corresponding to the 0 point varies for each ink key due to various factors such as the construction accuracy when the ink key is installed and the viscosity of the ink. Therefore, the 0 point of the ink key opening is not absolutely determined by the inclination of the ink key (that is, the mechanical ink key opening that can be objectively detected by a detecting means such as a potentiometer). It is necessary to set a point immediately before ink transfer is started on the sheet. Further, even if the 0 point is set once, the ink key opening corresponding to the 0 point gradually shifts as time passes.

  Therefore, when the ink key opening is automatically set, such as the ink key preset in the above-mentioned Patent Document 2, if there is an error in the 0 point setting, the ink key opening is set to an appropriate value according to the line rate of the printed pattern. Even if the user intends to do so, a setting error will actually occur, and automatic control will not function effectively, resulting in inconvenience such as the occurrence of waste paper. For this reason, it is very important to accurately set the 0 point of the ink key in the printing press.

  In setting the 0 point of this ink key, the operator has conventionally adjusted the ink film thickness on the ink source roller by adjusting the angle of the ink key by operating the adjusting screw etc. while visually observing the ink film thickness on the ink source roller. The film thickness was adjusted to about 0 point (about 5 microns). Then, the zero point of each ink key is set by storing the mechanical ink key opening detected at the adjusted point as a zero point in the storage device of the printing press.

However, in this case, since the operator manually sets the zero point, the operator has to perform complicated work, and the accuracy of the zero point to be adjusted is uneven due to variations in the skill level of the operator. was there.
Further, the adjustment of the zero point is performed based on the ink film thickness on the ink base roller, and is not based on the start of the transfer of the ink to the printing sheet, which is the original definition of the zero point. It was difficult to set points. In addition, in order to accurately adjust the zero point, in order to set the zero point based on the transfer of the ink to the printing sheet, the operator adjusts the angle of the ink key and the printing sheet while actually operating the printing machine. It is necessary to carry out the check alternately and the work load on the operator becomes extremely large, which is not realistic.

Because of these problems, a technique has been proposed in which 0 point setting is automatically performed without manually setting the 0 point (see Patent Document 3).
JP 2004-106523 A JP 2003-334929 A JP 2001-253055 A

  However, Patent Document 3 automatically adjusts the angle of the ink key so that the ink film thickness on the ink source roller becomes a predetermined film thickness while detecting the ink film thickness on the ink source roller with a sensor. In addition, since it is not the 0 point setting based on the transfer of the ink to the printing sheet, the problem that it is difficult to accurately set the 0 point as described above has not been solved yet.

  The present invention was devised in view of such a problem, and an object thereof is to provide an ink key 0 point setting method and an ink key 0 point setting device which can accurately and easily set an ink key 0 point. And

  In order to achieve the above-mentioned object, the ink key 0-point setting method according to the first aspect of the present invention includes a plurality of ink keys provided in a printing press and an opening control mechanism for controlling the opening of each ink key. In the ink supply device of the printing press, the ink key 0 point setting method, the opening step of the ink key is controlled by the opening control mechanism of the ink key, the detection step of detecting the start or end of the transfer of ink, A zero point setting step for setting the zero point of the ink key opening based on the detection result of the detection step is provided.

  According to a second aspect of the present invention, there is provided the ink key zero-point setting method according to the first aspect of the present invention, wherein the plurality of ink keys are disposed to face the ink base roller, and the opening degree control mechanism includes the plurality of ink key control mechanisms. Each of the plurality of ink keys is individually driven in a direction in which the ink keys are separated from and in contact with the ink base roller, and control means for controlling the operation of the actuators, and the respective mechanical openings of the plurality of ink keys are obtained. An opening degree obtaining means for performing the detection, and the detecting step includes: a first step for setting the ink key and the ink base roller in a non-ink supply state; and the actuator is operated by the control means after the first step. A second step of driving the ink key to the open side by a predetermined minute unit opening; and after the second step, A third step of printing a predetermined number of preset images while maintaining the opening of the ink key, and whether or not the transfer of ink to the print sheet has been started from the print result during printing in the third step A fourth step, and periodically repeats the second step to the fourth step until it is determined in the fourth step that the transfer of ink to the printing sheet has started. When it is determined in the fourth step that the transfer of ink to the printing sheet has started, the opening of the ink key one cycle before the determination is set as 0 point.

  According to a third aspect of the present invention, there is provided the ink key zero point setting method according to the first aspect of the present invention, wherein the plurality of ink keys are arranged to face the ink base roller, and the opening degree control mechanism includes the plurality of ink key control mechanisms. Each of the plurality of ink keys is individually driven in a direction in which the ink keys are separated from and in contact with the ink base roller, and control means for controlling the operation of the actuators, and the respective mechanical openings of the plurality of ink keys are obtained. Opening degree obtaining means for performing the detection, and the detecting step is configured to set the ink key in advance by operating the actuator by the control means after the first step of setting the ink key to an ink supply state, and after the first step. A second step for driving the minute unit opening to the closing side, and after the second step, the opening of the ink key is maintained. A third step of printing a predetermined number of images set in advance, and a fourth step of determining whether or not the transfer of ink to the print sheet has been completed based on the print result when printing is performed in the third step; Until the transfer of ink to the print sheet is determined to be completed in the fourth step, the fourth step is periodically repeated from the second step, and the fourth step When it is determined that the transfer of the ink to the printing sheet is completed, the opening of the ink key one cycle before the determination is set as 0 point.

  According to a fourth aspect of the present invention, there is provided the ink key zero-point setting method according to the second or third aspect of the present invention, wherein the ink sensor for detecting the ink on the printing sheet is provided in the running line of the printing sheet of the printing press. In the fourth step, the start or end of the transfer of the ink to the printing sheet is determined based on the detection result of the ink sensor. Any ink sensor may be used as long as it can determine whether or not ink has been transferred to a printing sheet such as an IRGB densitometer, a spectrometer, or a camera.

According to a fifth aspect of the present invention, there is provided the ink key zero point setting method according to the present invention, wherein the opening degree obtaining means detects the opening degree of the ink key. The opening degree of the ink key set as the zero point is determined based on the detection value of the ink key opening degree sensor.
According to a sixth aspect of the present invention, there is provided the ink key zero-point setting method according to any one of the second to fifth aspects, wherein the predetermined pattern has a single color and extends in the entire width direction of the printing sheet. It is characterized by a pattern with a stroke rate.

According to a seventh aspect of the present invention, there is provided the ink key zero-point setting method according to the sixth aspect of the present invention, wherein the predetermined pattern is the above-described single-color, high-image-ratio pattern for each ink color used. It is characterized by a pattern arranged side by side.
Note that the above-mentioned pattern with a single color and a high image rate is preferably a monochrome image with a maximum image rate of 100%, but may have a high image rate of 80% or more, for example. It is not limited to the stroke rate itself.

According to an eighth aspect of the present invention, there is provided the ink key zero point setting method according to the first aspect of the invention, wherein the ink key zero point setting is simultaneously performed for a plurality of the ink keys that are not adjacent to each other. It is characterized by.
The ink key zero-point setting device according to claim 9 of the present invention is the ink supply device for a printing press having a plurality of ink keys and an opening control mechanism for controlling the opening of each ink key. Detecting means for detecting the start or end of ink transfer by controlling the opening of each ink key by a mechanism; and 0 point setting means for setting 0 point of the ink key opening based on the detection result of the detecting means; It is characterized by having.

  An ink key zero-point setting device according to a tenth aspect of the present invention is the ink key zero-point setting device according to the ninth aspect, wherein the plurality of ink keys are arranged to face an ink base roller, and the opening degree control mechanism includes the plurality of opening degree control mechanisms. And an ink key control means for controlling the operation of the actuator, and an opening degree for obtaining a mechanical opening degree of the ink key. Upon receiving the acquisition means, the input means for inputting the 0-point setting command signal, and the 0-point setting command signal input by the input means, the ink key and the ink base roller are brought into a non-ink supply state, and the printing machine And the actuator is operated through the ink key control means to set the ink key to a predetermined minute unit. Periodically until a stop signal is input, a drive command to drive the opening side by the opening degree and a print command to print a predetermined number of presets while holding the opening degree of the ink key A printing control unit for controlling the printing press; and at the time of printing by the control of the printing control unit, whether or not the transfer of ink to the printing sheet has been started is determined from the printing result based on the detection result of the detection unit. When it is determined by the determination means and the determination means that the transfer of the ink to the print sheet has started, the opening degree of the ink key one cycle before the determination is set as 0 point, and the print control means The zero point setting means for outputting a stop signal is provided.

  An ink key zero-point setting device according to an eleventh aspect of the present invention is the ink key zero-point setting device according to the ninth aspect, wherein the plurality of ink keys are arranged to face an ink base roller, and the opening degree control mechanism includes the plurality of opening degree control mechanisms. And an ink key control means for controlling the operation of the actuator, and an opening degree for obtaining a mechanical opening degree of the ink key. Upon receiving the acquisition means, the input means for inputting the zero point setting command signal, and the zero point setting command signal input by the input means, the ink key and the ink base roller are brought into contact with each other, and the printing press is operated. At the same time, the actuator is operated through the ink key control means, and the ink key has a preset minute unit opening degree. The printing press periodically drives a drive command for driving to the closing side and a print command for printing a predetermined number of images while maintaining the opening of the ink key until a stop signal is input. A printing control unit that controls the printing control unit, and a determination unit that determines whether or not the transfer of the ink to the printing sheet is completed from the printing result based on the detection result of the detection unit during printing by the control of the printing control unit. When the determination means determines that the transfer of the ink to the print sheet has been completed, the opening degree of the ink key one cycle before the determination is set as 0 point, and a stop signal is sent to the print control means. And a zero point setting means for outputting.

  In addition, the ink key 0 point setting device according to the twelfth aspect of the present invention according to the tenth or eleventh aspect includes an ink sensor for detecting ink on the print sheet in a travel line of the print sheet, and the determination means. Is characterized in that it is determined whether or not ink has been transferred to the printing sheet based on the detection result of the ink sensor. The ink sensor may be any sensor that can determine whether or not ink has been transferred to a printing sheet, such as an IRGB densitometer, a spectrometer, or a camera.

An ink key 0 point setting device according to a thirteenth aspect of the present invention is the ink key zero point setting device according to any one of the tenth to twelfth aspects, wherein the opening degree obtaining means detects an opening degree of the ink key. The zero point setting means sets the zero point based on a detection value of the ink key opening sensor.
An ink key zero point setting device according to a fourteenth aspect of the present invention is the ink key zero point setting device according to any one of the tenth to thirteenth aspects, wherein the actuator simultaneously operates a plurality of the ink keys that are not adjacent to each other. Yes.

  According to a fifteenth aspect of the present invention, there is provided an ink key zero point setting method for a printing press according to the present invention, wherein a plurality of ink keys provided in the printing press and an opening degree of each ink key are controlled based on a printing result to automatically control a print color tone. An ink key zero point setting method in an ink supply device of a printing press having an opening control mechanism for performing printing by automatic color tone control of the opening control mechanism, and for each key zone of each ink key The first step of acquiring and storing a plurality of ink key opening information corresponding to the image line ratio, and linear approximation based on the ink key opening value and the image line ratio stored in the first step. And a second step of setting an ink key opening degree corresponding to a case where the image line ratio is 0 to an ink key 0 point.

  The ink key zero-point setting method for a printing press according to a sixteenth aspect of the present invention is the method according to the fifteenth aspect, wherein the plurality of ink keys are arranged to face an ink base roller, and the opening degree control mechanism is , An actuator for individually driving the ink key in a direction to be separated from and contacting the ink base roller, an opening degree obtaining means for obtaining a mechanical opening degree of the ink key, and detecting a color density of the printed sheet The IRGB densitometer and the operation of the actuator to control the opening of the ink key so that the printed image has a target drawing rate based on the measurement result of the IRGB densitometer, thereby adjusting the print color tone. Control means for automatically controlling, and in the first step, a first color which is only a single color of the ink color of the ink key to be adjusted among the ink keys and has a first image ratio. When the pattern is printed, the value of the ink key opening at the time when the automatic color tone control by the control means has converged is stored as the first ink key opening together with the first image ratio, and only the ink color of the ink key to be adjusted is stored A second image having a second color rate different from the first image rate and printing the second image, and the value of the ink key opening at the time when the automatic color tone control by the control means converges is set to the second ink key. The opening is stored together with the second stroke ratio, and in the second step, the first ink key opening, the first stroke ratio, and the second ink key opening stored in the first step are stored. The ink key opening degree corresponding to the case where the image line rate is 0 is set to the 0 point of the ink key by linear approximation or curve approximation based on the degree and the second image line rate.

  The ink key zero-point setting method for a printing press of the present invention according to claim 17 is the one according to claim 15, wherein the plurality of ink keys are arranged to face an ink base roller, and the opening degree control mechanism is , An actuator for individually driving the ink key in a direction to be separated from and contacting the ink base roller, an opening degree obtaining means for obtaining a mechanical opening degree of the ink key, and detecting a color density of the printed sheet The IRGB densitometer and the operation of the actuator to control the opening of the ink key so that the printed image has a target drawing rate based on the measurement result of the IRGB densitometer, thereby adjusting the print color tone. Control means for automatically controlling, and in the first step, every time actual product printing is performed, the image line rate and the ink key opening corresponding to the image line rate are set for each key zone. Obtaining and storing a plurality of image line ratios and ink key openings corresponding to the image line ratios for each key zone, and storing them in the first step in the second step. Based on a plurality of sets of the ink key opening and the line drawing rate, the ink key opening stored in the first step for setting the ink key opening corresponding to the case where the line drawing rate is 0 by linear approximation to the 0 point of the ink key is stored. In the second step, the first step includes setting the ink key opening degree corresponding to the case where the image line rate is 0 by linear approximation based on the value of the image and the image line rate to the ink key 0 point. Based on the value of the ink key opening and the line drawing rate stored in the step, the ink key opening corresponding to the case where the line drawing rate is 0 is set to the ink key 0 point by linear approximation or curve approximation. It is characterized by a door.

  An ink key zero-point setting device for a printing press according to the present invention according to claim 18 includes a plurality of ink keys arranged to face the ink base roller, and directions in which the ink keys are separated from and contacted with the ink base roller. Based on the measurement results of the IRGB densitometer, the actuator for individually driving the actuator, the opening degree obtaining means for obtaining the mechanical opening degree of the ink key, the IRGB densitometer for detecting the color density of the printed sheet. Automatic color tone control comprising control means for controlling the color tone of printing by automatically controlling the opening of the ink key by controlling the operation of the actuator so that the pattern to be printed becomes a target line drawing rate In an ink supply device for a printing press with a function, the ink key opening at the boundary point where ink transfer can actually start on the printing sheet is set as 0 point. A key 0-point setting device, wherein the first printing plate for printing a first picture which is a single color of the ink color of the ink key to be adjusted among the ink keys and which has a first drawing rate; A second printing plate for printing a second pattern that is a single color of only the ink color of the ink key to be adjusted and has a second drawing rate different from the first drawing rate, and the first printing A pattern by a plate is printed, and the value of the ink key opening at the time when the automatic color tone control by the control means has converged is stored as the first ink key opening together with the first image ratio, and by the second printing plate Storage means for printing a picture and storing the value of the ink key opening at the time when the automatic color tone control by the control means converges as the second ink key opening together with the second image ratio, and stored in the storage means The first ink key opening And the ink key opening corresponding to the case where the drawing rate is 0 by linear approximation or curve approximation based on the first drawing rate, the second ink key opening and the second drawing rate. It is characterized by having 0 point setting means for setting a point.

Therefore, according to the ink key 0 point setting method of the present invention as set forth in claim 1 and the ink key 0 point setting device as set forth in claim 9, the 0 point of the ink key opening is set based on the start or end of ink transfer. Therefore, accurate zero point setting can be performed.
According to the ink key 0 point setting method of the present invention described in claim 2 and the ink key 0 point setting device according to claim 10, in addition to the effect of claim 1 or 8, Since it is not necessary for the operator to manually adjust the ink key opening, it is possible to reduce the operator's work load for setting the 0 point of the ink key. Furthermore, since the 0 point of the ink key is determined based on the printing result of actual printing, it is possible to set the 0 point of the ink key with higher accuracy than before.

  According to the ink key 0 point setting method of the present invention described in claim 3 and the ink key 0 point setting device according to claim 11, in addition to the effect of claim 1 or 8, when performing 0 point setting of the ink key, Since it is not necessary for the operator to manually adjust the ink key opening, it is possible to reduce the operator's work load for setting the 0 point of the ink key. Furthermore, since the 0 point of the ink key is determined based on the printing result of actual printing, it is possible to set the 0 point of the ink key with higher accuracy than before. In addition, the ink key 0 point setting suitable for the actual ink key opening automatic control can be performed.

According to the ink key 0 point setting method of the present invention as set forth in claim 4 and the ink key 0 point setting device as set forth in claim 12, in addition to the effects of claims 2, 3, 10, and 11, The ink sensor provided can reliably detect the ink transferred onto the printing sheet.
According to the ink key 0 point setting method of the present invention as set forth in claim 5 and the ink key 0 point setting device as set forth in claim 13, in addition to the effects of claims 2 to 4 or claims 10 to 12, an ink key opening sensor Thus, the ink key opening can be detected accurately, and the 0 point is set based on the detected value, so that the 0 point of the ink key can be set with high accuracy.

  According to the sixth aspect of the present invention, in addition to the effects of the second to fifth aspects, the image extending in the entire width direction of the print sheet is printed. The ink key can also be set to 0 point, and the ink key can be accurately transferred to the printing sheet based on the result of printing a high-line-ratio image with which ink is easily transferred. Settings can be made.

According to the ink key 0 point setting method of the present invention described in claim 7, in addition to the effect of claim 6, it is possible to simultaneously set 0 ink key for each ink color to be used. Such time can be shortened.
Further, according to the ink key 0 point setting method of the present invention described in claim 8 and the ink key 0 point setting device described in claim 14, in addition to the effects of claims 1 to 7 or claims 9 to 13, a plurality of not adjacent to each other. Since the 0 point setting of the ink key is performed simultaneously, it is possible to simultaneously control a plurality of ink keys to shorten the time required to set the 0 point of the ink key. At this time, the remarkable hysteresis caused by the interference of the adjacent ink keys with each other It is possible to prevent an error from occurring in the zero point setting due to the influence of the phenomenon.

  According to the ink key 0-point setting method of the present invention as set forth in claim 15, the ink key 0 is obtained from information on a plurality of ink key opening degrees corresponding to the actual image area ratio obtained by printing by automatic color tone control. Since the point is estimated, it is possible to set the 0 point of the ink key with high accuracy based on the actual printing result, and it is possible to shorten the time required for setting the 0 point of the ink key.

  Further, in addition to the effect of claim 15, the ink key 0 point setting method of the present invention according to claim 16 does not require the operator to manually adjust the ink key opening when setting the 0 point of the ink key. It is possible to reduce an operator's work load for setting the 0 point of the ink key. Furthermore, since a plurality of patterns with different image line rates are actually printed and the 0 point of the ink key is estimated based on the printing result, the 0 point of the ink key can be set with high accuracy, and the 0 of the ink key can be set. The time required for point setting can be shortened.

Further, according to the ink key 0 point setting method of the present invention described in claim 17, in addition to the effect of claim 15, it is not necessary to perform printing only for setting the zero point, and the work load for setting the zero point is reduced. At the same time, the zero point setting is performed at the same time as printing the product, so that the problem of delaying the printing of the product due to the zero point setting can be prevented.
In addition, according to the ink key 0 point setting device according to claim 18, the operator does not need to manually adjust the ink key opening when setting the 0 point of the ink key. The work load can be reduced. Furthermore, since a plurality of patterns with different image line rates are actually printed and the 0 point of the ink key is estimated based on the printing result, the 0 point of the ink key can be set with high accuracy, and the 0 of the ink key can be set. The time required for point setting can be shortened.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a flowchart showing a control flow for explaining an ink key 0-point setting method, FIG. 2 is a schematic side view showing a schematic configuration of a printing press equipped with an ink key 0-point setting device of the present invention, and FIGS. Fig. 5 is a schematic diagram showing the configuration of the ink supply device of the printing machine, Fig. 5 is a block diagram showing the functional configuration of the control system related to the setting of the ink key 0 point, and Fig. 6 is a diagram showing a predetermined print pattern related to the setting of the ink key 0 point. is there.

  First, a schematic configuration of a printing machine including an ink key 0 point setting device according to the present embodiment will be described. FIG. 2 is a diagram showing a schematic configuration of an offset rotary press as a printing press provided with the ink key 0-point setting device according to the present embodiment. The offset rotary press in the present embodiment is a multicolor double-sided printing press, and ink colors [black (k), indigo (c), red (m), yellow (y)] along the conveyance path of the printing sheet 8. Printing units 2a, 2b, 2c, and 2d are installed for each. Each of the printing units 2a, 2b, 2c, and 2d is provided with an ink supply device 5 including an ink key 7 and an ink source roller 8. A control device 20 such as a computer is connected to each ink supply device 5, and the control device 20 adjusts the gap amount (that is, the ink key opening) of the ink key 7 with respect to the ink base roller 8. The ink supply amount in the apparatus 5 can be adjusted. Details of the configuration relating to the ink key opening adjustment of the ink supply device 5 and the configuration of the control device 20 will be described later.

  The ink whose supply amount is adjusted by the ink supply device 5 is moderately kneaded in the ink roller group, supplied to the plate surface of the plate cylinder 4 after forming a thin film, and the ink adhering to the plate surface passes through the blanket cylinder 3. It is transferred to the printing sheet 8 as a picture. Although not shown, since the offset rotary press of this embodiment is a double-sided printing, each printing unit 2a, 2b, 2c, 2d is provided with a pair of blanket cylinders 3 so as to sandwich the conveyance path of the printing sheet 8. A plate cylinder 4 and an ink supply device 5 are provided for each blanket cylinder 3.

The offset rotary press of this embodiment includes a line sensor type IRGB densitometer 1 further downstream of the most downstream printing unit 2d as an ink sensor that detects printed ink. The IRGB densitometer 1 is a measuring instrument that measures the reflected light of the ink transferred onto the printing sheet 8 as the reflection density of I (infrared light), R (red), G (green), and B (blue). It is also possible to measure the reflection density of the entire width of the print sheet 8 or to measure the reflection density at an arbitrary position. In the present embodiment, it is determined by the IRGB densitometer 1 whether or not ink has been transferred to the print sheet.
Since the offset rotary press prints on both sides, the IRGB densitometer 1 is arranged on both the front and back sides so as to sandwich the conveyance path of the print sheet, and the reflection density on both the front and back sides can be measured. The ink sensor is not limited to an IRGB densitometer, and a spectrometer, an image camera, or the like may be used.

[Ink supply device]
Next, the configuration of the ink supply device 5 will be described with reference to FIGS. 3 and 4. As shown in FIGS. 3 and 4, the ink supply device 5 is provided with an ink source roller 6, an ink key 7, and an ink transfer roller 9. From the peripheral surface of the ink source roller 6, the ink key 7 and the side plates 10a and 10b. The ink stored in the ink fountain is formed in each printing unit from the gap between the ink key 7 and the peripheral surface of the ink source roller 6 through the peripheral surface of the ink source roller 6, the ink transfer roller 9, and a group of ink kneading rollers (not shown). It supplies to 2a-2d.

  Further, as shown in FIG. 4, a plurality of ink keys 7a to 7h are arranged in the printing width direction, and the adjacent ink keys 7a to 7h and the end ink keys 7a and 7h and the side plates 10a and 10b are in sliding contact with each other. . Further, as shown in FIG. 3, the ink keys 7 a to 7 h can swing independently about the fulcrum shaft 51, and the gaps between the ink keys 7 a to 7 h and the peripheral surface of the ink source roller 6. (Ink key opening) can be adjusted. An ink key opening degree adjusting device 50 is provided below the ink keys 7a to 7h.

  The ink key opening adjusting device 50 includes a push-up metal 55 that contacts the lower surface of the front end of each ink key 7a to 7h, a pusher 56 that contacts the front end of the press-up metal 55 and expands and contracts the push-up metal 55 by extending and contracting in the front-rear direction. , And a motor 53 as an actuator connected so as to move the pusher 56 forward or backward by being rotationally driven. The motor 53 is electrically connected to the control device 20 so as to be driven and controlled by the control device 20. The rotating shaft of the motor 53 is connected to the adjusting screw 52 through a gear so that the drive can be transmitted. That is, the pusher 56 can be moved forward or backward by rotating the adjusting screw 52.

  Further, the rotation shaft of the motor 53 is connected to a potentiometer 54 for detecting the rotation angle position of the rotation shaft so as to be able to transmit drive via a gear. The rotation angle of the motor 53 detected by the potentiometer 54 corresponds to the forward / backward position of the pusher 56, that is, the swing angle of the ink key 7, whereby the gap between the ink key 7 and the ink base roller 6 (that is, the mechanical ink key). Opening degree) can be detected. That is, here, the potentiometer 54 functions as an ink key opening sensor. The potentiometer 54 is electrically connected to the control device 20 so that the detection result is input to the control device 20.

  As described above, the ink key opening degree adjusting device 50 can adjust the ink key opening degree by rotating the motor 53 or the adjusting screw 52 and swinging the ink key 7 via the pusher 56 and the push-up bracket 55. It has a configuration. That is, here, the ink key opening adjustment device 50 and the control device 20 function as an ink key opening control mechanism.

[Functional configuration of control system]
Next, the functional configuration of the control system for setting the ink key 0 point will be described with reference to FIG. FIG. 5 is a block diagram showing a functional configuration of a control system according to the ink key 0 point setting of the present invention.
As shown in FIG. 5, the apparatus configuration relating to the control system for setting the ink key 0 point is the IRGB densitometer 1, the ink supply device 5, the control device 20, and the input means 25.
The control device 20 is supplied with a detection signal from a potentiometer 54 provided in the ink key opening adjustment device 50 and a detection signal from the IRGB densitometer 1. Further, the control device 20 is electrically connected to the motor 53 of the ink key opening adjustment means 50 so that the control device 20 can control the drive of the motor 53.

The input unit 25 is, for example, an input device such as a touch panel electrically connected to the control device 20. When an instruction for setting an ink key 0 point is input by an operator or the like, a 0-point setting command is sent to the print control unit 21. A signal is input.
The control device 20 includes a print control unit 21, a zero point setting unit 23, and a determination unit 24 as functional elements. The print control unit 21 includes an ink key control unit 22.

  The printing control means 21 controls the operation of the printing press, and the ink key opening degree can be adjusted by the ink key control means 22. Here, the ink key opening degree is increased and adjusted stepwise. Based on the signal input from the IRGB densitometer 1, the determination unit 24 determines whether or not ink has been transferred to the print sheet, and inputs the determination result to the 0-point setting unit 23. A detection signal corresponding to the ink key opening is input from the potentiometer 54 to the zero point setting unit 23, and printing is performed when a determination result indicating that the ink has been transferred to the print sheet 8 is input from the determination unit 24. A stop signal (stop signal) is input to the printing control means 21, and an opening that is one step smaller than the ink key opening at that time obtained based on the input signal from the potentiometer 54 is set as the zero point. .

[Control flow chart]
Hereinafter, with reference to the flowchart shown in FIG. 1, the ink key 0 point setting according to the present embodiment will be described.
As shown in FIG. 1, first, when a 0-point setting command signal is input from the input means 25 to the print control means 21 of the control device 20 in step S101, the ink key control means 22 causes the ink key 7 and the ink key in step S102. The drive of the motor 53 is controlled so that the original roller 6 is in contact (initial setting of the ink key opening). The contact state is preferably a limit state just before contact, and may be a state in which ink is not supplied from the gap between the ink key 7 and the ink source roller 6 (non-ink supply state). In step S103, the ink key control unit 22 controls the motor 53 so that the ink key 7 is opened by a predetermined opening (a minute unit opening) ΔS, and then in step S104, the printing control unit 21 Start the printing operation by operating the printing press.

This printing operation will be described in detail. When the ink key 0 point is set, the plate cylinder 3 of each of the printing units 2a to 2d has a predetermined print flow direction length over the entire printable width as shown in FIG. A printing plate having a printing pattern is mounted so that a line drawing ratio of 100% of a single color having a color is juxtaposed in the printing flow direction for each ink color.
Then, the printing control means 21 performs a printing operation for a predetermined number t with the above-described printing plate of the predetermined pattern at the ink key opening set in step S103. The predetermined number t is a numerical value that can be detected from the number of rotations of the plate cylinder 3 (how many times it has been rotated) counted by a counter (not shown). Thus, after the opening degree of the ink key 7 is increased, the predetermined number t is The reason for printing a few t is that a response delay occurs before the increase in the ink key opening appears as an actual printing result. For this reason, the predetermined number t is set to a minimum value at which the effect of increasing the ink key opening can be reliably reflected in the printing result.

In step S105, based on the detection signal of the reflected light of the print sheet 8 that has been input from the IRGB densitometer 1 and passed through the print units 2a to 2d, the determination unit 24 transfers the ink to the print sheet 8. It is determined whether or not.
In step S105, if the determination means 24 determines that the ink has not been transferred to the printing sheet 8, the process returns to step S103 again, and the ink key control means 22 releases the ink key 7 by a predetermined opening ΔS from the current opening. In step S104, the above-described printing operation is performed again. The control from step S103 to step S105 is periodically repeated until it is determined that the ink has been transferred to the printing sheet 8. The control from step S103 to step S105 is called one cycle.

  If it is determined in step S105 that the ink has been transferred to the printing sheet 8, in step S106, the 0-point setting means 23 is based on the input signal from the potentiometer 54, and the ink key opening (that is, the current ink key) in the previous cycle. The ink key 0 point is set by storing the value obtained by subtracting the predetermined opening ΔS from the opening) as the ink key opening corresponding to the ink key 0 point. In step S107, a stop signal is input from the 0-point setting unit 24 to the print control unit, and the operation of the printing press is stopped.

  It is preferable that the control for setting the above-described ink key 0 point is simultaneously performed for a plurality of ink keys 7 that are not adjacent to each other in the ink supply device 5. As combinations of a plurality of ink keys 7 that are not adjacent to each other, in the ink keys 7a to 7j shown in FIG. 4, combinations of ink keys 7a, 7c, 7e, 7g, 7i (group A) and combinations of ink keys 7b, 7d, 7f, 7h, 7j (Group B) etc. can be considered.

  For example, the ink keys 7a to 7j may be divided into the above-described group A and group B, and the ink key 0 point setting may be simultaneously performed for all the ink keys included in the group for each group. In this case, in order to set the zero point for all the ink keys 7a to 7j, the control of steps S102 to S106 in FIG. The control in steps S102 to S106 may be performed.

In this way, by not setting the ink key 0 point for the ink keys 7 adjacent to each other at the same time, an error occurs in the zero point setting due to the remarkable hysteresis phenomenon that occurs when the adjacent ink keys interfere with each other. This can be prevented.
Since the ink key 0 point setting method and the 0 point setting device of the printing press according to the first embodiment of the present invention are configured as described above, when the ink key 0 point setting is performed, first, the ink key opening degree is 0. Since the ink key 7 is opened only by a predetermined opening S every cycle after the setting, the printing operation is actually performed, and the control of detecting the ink transferred onto the printing sheet 8 is automatically performed. It is not necessary for the operator to manually set the ink key 0 point, and the operator's work load can be reduced. Further, when setting the 0 point of the ink key, the 0 point of the ink key is set based on the presence / absence of the ink transferred on the printing sheet 8 on which printing has actually been performed, so that the transfer of the ink to the printing sheet 8 is actually started. The boundary point can be found with high accuracy, and the ink key 0 point can be set with high accuracy.

  As a result, when the ink key opening degree is automatically preset based on the line rate of the printed pattern before printing, the error due to the deviation of the ink key 0 point can be reduced. Can be quickly brought to a desired color tone, thereby reducing the occurrence of waste paper.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the configuration of the printing press according to FIGS. 2 to 4 of the first embodiment is common, and description of portions common to the first embodiment is omitted. In addition, components common to the first embodiment will be described using the same reference numerals.
In the present embodiment, ink density control (automatic color tone control) is performed for printing a plurality of patterns having different image line ratios, and ink key opening degrees corresponding to the plurality of image line ratios are acquired. The functional configuration and control aspect of the control system are different from those of the first embodiment described above.

Hereinafter, the functional configuration of the control system in the present embodiment will be described with reference to FIG.
As shown in FIG. 7, the apparatus configuration of the control system for setting the ink key 0 point in this embodiment is an IRGB densitometer 1, an ink supply device 5, a control device 20 ′, and an input means 25.
Among these, the IRGB densitometer 1, the ink supply device 5, and the input means 25 are the same as those in the first embodiment, and the functional configuration of the control device 20 ′ is different from that in the first embodiment.

The control device 20 ′ includes a printing control unit 31 including an ink key control unit 32, a zero point calculation / setting unit 33, and an ink density control unit 40 as functional elements.
The input side of the print control means 31 is connected to the input means 25, the zero point calculation / setting means 33, and the output side of the ink density control means 40, and the output side of the print control means 31 is connected to the motor 53. ing. The input side of the zero point calculation / setting means 33 is connected to the ink density control means 40 and the potentiometer 54, and the input side of the ink density control means 40 is connected to the IRGB densitometer 1 and the input means 25.

The print control means 31 receives the 0-point setting command signal input from the input means 25 and controls the operation of the printing press so as to appropriately print a predetermined first picture and second picture to be described later. The ink key control means 32 controls the motor 53 based on the ink key opening command value input from the ink density control means 40 during printing.
Here, the first pattern and the second pattern according to the present embodiment will be described with reference to FIG. FIG. 8A shows the first picture, and FIG. 8B shows the second picture. In the present embodiment, the zero point estimation calculation is performed based on the printing results of a plurality of patterns having different image line ratios, and the number of patterns may be three or more. The name of the first pattern, the second pattern, or the printing order can be changed as appropriate. Each printing unit 2a, 2b, 2c, 2d is provided with a first printing plate for printing the first picture and a second printing plate for printing the second picture, Mounted as appropriate.

  As shown in FIGS. 8A and 8B, each of the first pattern and the second pattern in the present embodiment is a monochrome pattern having a predetermined print flow direction length over the entire printable width. Are juxtaposed in the print flow direction for each ink color, and only the respective line rate is 10% for the first pattern line rate (first line rate). The stroke rate of the pattern (second stroke rate) is different from 3%. Note that the line ratios of the first and second patterns are not limited to 10% and 3%, but they are set to relatively low line ratios and different line ratios by an appropriate amount.

The ink density control means 40 outputs the ink key opening command value based on the print data inputted from the outside or the printing data stored in the control device 20 'and the detection signal of the IRGB densitometer, and outputs the ink key opening degree. Is controlled automatically so that the ink density transferred onto the printing sheet 8 becomes a desired ink density based on the printing data.
The ink density control means 40 includes an ink density control convergence determination means 41 as a functional element. The ink density control convergence determining means 41 determines that the ink key control opening degree adjustment control for the ink density control in the ink density control means 40 has converged and the ink density control has shifted to a steady state. When it is determined that the state has shifted to the steady state, an ink density control convergence determination signal is input to the zero point calculation / setting means 33. Details of the ink density control will be described later.

  In the zero point calculation / setting means 33, the ink density control in the first pattern has converged based on the ink key opening detection signal input from the potentiometer 54 and the ink density control convergence determination signal input from the ink density control means 40. The ink key opening at the time is stored as the first opening S1, and the ink key opening at the time when the ink density control in the second pattern has converged is stored as the second opening S2. Then, based on the stored first opening S1 and second opening S2, the ink key opening S0 corresponding to the ink key 0 point is estimated (hereinafter referred to as 0 point calculation), and the ink key opening calculated thereby is calculated. Is set as 0 point.

  Hereinafter, the zero point calculation will be described with reference to FIG. FIG. 9 corresponds to the first opening Y1 and the second drawing ratio X2 corresponding to the first drawing ratio X1 with the printing pattern drawing ratio on the X axis and the ink key opening on the Y axis. The second opening Y2 is plotted in this XY coordinate system. Here, the ink key opening is the mechanical ink key opening detected by the potentiometer 54, and is different from the ink key opening with the zero point of the ink key in the API function as the origin. The ink key opening in the API function is obtained by correcting the mechanical ink key opening by 0 point.

The relationship between the mechanical ink key opening and the line drawing rate is as follows. When the line drawing rate is X and the ink key opening is Y, Y = aX + b
The value of the ink key opening degree Y (that is, the value of b) when the image area ratio X is 0 corresponds to 0 point. In addition to the linear approximation, approximation with an appropriate curve may be considered.
Here, these values X1, Y1, and Y1 are obtained by obtaining the ink key opening Y1 with respect to the first image ratio X1 (10%) and the ink key opening Y2 with respect to the second image ratio X2 (3%). B is calculated from X2 and Y2 by the following equation.

b = (X1, Y2-X2, Y1) / (X1-X2)
Hereinafter, the ink key 0 point setting in the present embodiment will be described with reference to FIG.
As shown in FIG. 10, first, in step S201, when a 0-point setting command signal is input from the input unit 25 to the print control unit 31 of the control device 20 ', in step S202, the print control unit 31 is connected to the printing machine. The operation is controlled to print the first picture. Here, the first printing plate for printing the first pattern may be manually attached to the plate cylinder 3 by an operator in advance, or may be made on the printing machine from the plate making data of the first pattern. .

  When printing of the first pattern is started in step S202, ink density control by the ink density control means 40 is started in step S203. The details of the ink density control will be described later. At this time, the ink density control means 40 inputs the ink key opening command value signal to the ink key control means 32 to adjust the ink key opening and supply the ink supplied to the plate cylinder 3. Control the supply amount. This ink supply amount control is feedback control based on preset print data (here, the first picture) and an ink density signal input from the IRGB densitometer 1. In step S204, the ink density control convergence determination unit 41 of the ink density control unit 40 determines whether the feedback control has converged.

In step 204, if the ink density control convergence determination means 41 determines that the ink density control has not converged, the process returns to step S203, where the ink density control is continued, and it is determined that the ink density control has converged. Then, an ink density convergence determination signal is sent to the zero point calculation / setting means 33.
When the ink density convergence determination signal is input to the zero point calculation / setting means 33, the zero point calculation / setting means 33, in step S205, from the signal input from the potentiometer 54, the ink key opening (first first) And the stop signal is sent to the printing control means 31. Then, when a stop signal is input to the print control means 31, the operation of the printing press is stopped, and the printing of the first pattern is completed. Here, the first printing plate (first printing plate) and the second printing plate for printing the second pattern are exchanged. In this case, the second pattern printing plate may be manually attached to the plate cylinder 3 by an operator in advance, or may be made on the printing machine from the plate making data.

Next, as a step S206, the second pattern is printed. The printing of the second pattern may be started by the operator inputting a printing start signal to the printing control means 31 by the input means 25 after the printing plate replacement is completed, or printing is automatically performed upon completion of the printing plate replacement. It may be started.
When the printing of the second pattern is started, ink density control by the ink density control means 40 is started as step S207. Then, the ink density control is performed in the same manner as in step S203 described above. In step S208, the ink density control convergence determination unit 41 determines whether the ink density control has converged. In step S208, if it is determined that the ink density control has not converged, the process returns to step S207, and the ink density control is continued. If it is determined that the ink density control has converged, the ink density is set to the zero point calculation / setting unit 33. A convergence determination signal is sent out. In step S209, the zero point calculation / setting unit 33 stores the ink key opening (second opening Y2) at that time from the signal input from the potentiometer 54, and sends a stop signal to the printing control unit 31. Then, the operation of the printing press is stopped.

  At this time, the zero point calculation / setting means 33 performs the zero point calculation as described above based on the stored first opening degree Y1 and second opening degree Y2 as step S210, and corresponds to the ink key 0 point. The ink key opening is estimated and calculated, and the calculated ink key opening is set as 0 point in step S211. Then, an ink key 0 point setting completion signal is output and the control is terminated.

[Ink supply control]
Here, details of ink density control control according to the second embodiment of the present invention will be described.
FIG. 11 is a diagram showing a schematic configuration of the ink density control device 40 of the offset rotary press according to the second embodiment of the present invention, and at the same time, a functional block diagram focusing on the ink density control function.
The ink density control means 40 includes a DSP (digital signal processor, which has a function corresponding to a pixel-of-interest setting means, an image rate calculation means, and an actual color mixture halftone density measurement means) 31, a color converter (target color mixture halftone density setting). Means, target image rate calculating means, target monochrome color density calculating means, actual image rate calculating means, actual monochrome color density calculating means, solid density deviation calculating means) 34, ink supply amount calculating unit 35 , An online control unit 36 and a key opening limiter calculation unit 37.

  The IRGB densitometer 1 is connected to the input side of the ink density control means 40, and the print control means 31 is connected to the output side. The printing control means 31 can adjust the key opening independently for each ink key 7 of each printing unit 2a, 2b, 2c, 2d by the ink key control means 32 as described above. Further, the input means 25 is connected to the ink density control means 40.

FIG. 12 is a diagram showing a processing flow of ink density control by the ink density control means 40. Hereinafter, the processing content of the ink density control by the ink density control means 40 will be described with reference to FIG.
In order to perform ink density control, it is necessary to determine some target value for feedback control. In this embodiment, since the reflection density, that is, the mixed color halftone density is measured using the line sensor type IRGB densitometer 1, in step S0, the target mixed color halftone density is set by the following procedure as the target value.

  First, the image ratio data Ak, Ac, Am, Ay for each key zone of each ink color in the predetermined print pattern this time is input from the input means 25 to the ink density control means 40. The drawing rate Ak, Ac, Am, Ay data can be obtained by measuring a film for plate making with a film scanner or by measuring a printing plate with a plate scanner. It can be easily obtained by using data. The color conversion unit 44 includes a database 48 that associates the image line ratio of each ink color with the mixed color halftone density. The database 48 is a newspaper printed by Japan Color standard established by the ISO / TC130 National Committee, and measured by an IRGB densitometer [standard color streak rate (k, c, m, y) and mixed color density It is created on the basis of (a conversion table that defines the correspondence between I, R, G, B) and color coordinate values (L, a, b). The color conversion unit 44 uses this database 48 to obtain the mixed color halftone density corresponding to the input image line ratios Ak, Ac, Am, Ay for each key zone, and the target mixed color halftone density Io, Ro, Go, Bo. Set as.

  Note that even if the print pattern has the same line rate Ak, Ac, Am, or Ay, the color density depends on the density of the print pattern (50% flat screen, 80% flat screen, solid, etc.) considering the dot gain. Concentration value to be different. Accordingly, the color conversion unit 44 can change the dot gain for each density of the halftone, and the parameters with the dot gain as a function can be used to set the image ratios Ak, Ac, Am, Ay to the mixed color halftone densities Io, Ro, Go, Bo. The target color mixture density Io, Ro, Go, Bo considering the dot gain can be set.

  When the target mixed color halftone densities Io, Ro, Go, Bo are set as described above, printing is started and the processes after step T10 are repeatedly executed. First, as step T10, the line sensor type IRGB densitometer 1 measures the reflected light amount i ', r', g ', b' for each pixel on the entire surface of the print sheet 8. The amount of reflected light i ′, r ′, g ′, b ′ of each pixel measured by the IRGB densitometer 1 is input to the DSP 11.

In step T20, the DSP 11 performs a moving average of the reflected light amounts i ′, r ′, g ′, and b ′ of each pixel in units of a predetermined number of printed sheets, so that the reflected light amounts i, r of each pixel from which the noise component has been removed. , G, b are calculated. In step T30, the reflected light amounts i, r, g, and b are averaged for each key zone, and the mixed color halftone density (actual mixed color halftone density) I, R, G, and B based on the reflected light amount of the blank paper portion is obtained. Calculate. For example, assuming that the reflected light amount of infrared light on the blank paper portion is ip and the average reflected light amount of infrared light in the key zone is ik, the actual mixed color halftone density I of infrared light is I = log ₁₀ (ip / ik) As required. The actual mixed color halftone densities I, R, G, and B for each key zone calculated by the DSP 11 are input to the color conversion unit 44.

  The color conversion unit 44 performs the processes of steps T40, T50, and T60. First, at step T40, the image of each ink color corresponding to the target mixed color halftone density Io, Ro, Go, Bo set at step T0 and the actual mixed color halftone density I, R, G, B calculated at step T30. Calculate the linearity respectively. For this calculation, the database 48 is used, and based on the correspondence stored in the database 48, the line ratio of each ink color corresponding to the target color mixture halftone density Io, Ro, Go, Bo is calculated as the target line ratio ko, co, It is calculated as mo, yo, and the image line ratio of each ink color corresponding to the actual mixed color halftone density I, R, G, B is calculated as the actual image line ratio k, c, m, y.

  Next, in step T50, the color conversion unit 44 calculates a single color halftone density of each ink color corresponding to the target image line ratios ko, co, mo, yo and the actual image line ratios k, c, m, y. To do. This calculation can be performed using a map as shown in FIG. FIG. 13 is an example of a map in which the monochromatic halftone density actually measured when the image line ratio is changed is plotted as a characteristic curve, and is created from data measured in advance. In the example shown in FIG. 13, by comparing the black target image rate ko and the actual image rate k with the map, the target single color halftone density Dako and the real single color halftone density Dak are obtained from the characteristic curves in the map, respectively. ing. In this way, the color conversion unit 44 obtains the target monochromatic halftone densities Dako, Dako, Damo, Dayo and actual monochromatic halftone densities Dak, Dac, Dam, Day for each ink color.

  Next, in step T60, the color conversion unit 44 determines the solid density deviation ΔDsk of each ink color corresponding to the deviation between the target monochrome color density Dako, Dako, Damo, Dayo and the actual monochrome color density Dak, Dac, Dam, Day. , ΔDsc, ΔDsm, ΔDsy are calculated. Note that the solid density also depends on the image line ratio. For the same monochromatic halftone density, the solid density decreases as the image line ratio increases. Therefore, the color conversion unit 44 performs calculations using a map as shown in FIG. FIG. 14 is an example of a map in which the monochromatic halftone density actually measured when the monochromatic solid density is changed is plotted as a characteristic curve for each line ratio, and is created from data measured in advance. The color conversion unit 44 selects a characteristic curve corresponding to the target drawing ratios ko, co, mo, yo for each ink color from the map shown in FIG. 14, and sets the target monochromatic halftone density Dako, Dako, Damo to the selected characteristic curve. , Dayo and the real monochromatic halftone densities Dak, Dac, Dam, Day are obtained to obtain solid density deviations ΔDsk, ΔDsc, ΔDsm, ΔDsy. In the example shown in FIG. 14, when the target line drawing ratio ko of black is 75%, the target monochrome color density Dako and the actual monochrome color density Dak are checked against the map, so that the black color can be obtained from the 75% characteristic curve in the map. A solid density deviation ΔDsk is obtained.

The solid density deviations ΔDsk, ΔDsc, ΔDsm, ΔDsy of each ink color calculated by the color conversion unit 44 are input to the ink supply amount calculation unit 15.
In step T70, the ink supply amount calculation unit 45 calculates the key opening deviation amounts ΔKk, ΔKc, ΔKm, ΔKy corresponding to the solid density deviations ΔDsk, ΔDsc, ΔDsm, ΔDsy. The key opening deviation amounts ΔKk, ΔKc, ΔKm, ΔKy are increments / decrements relative to the key openings Kk, Kc, Km, Ky of the ink keys 7 output to the printing control means 31 in the previous processing of step T110. As the line drawing ratio A, the one used in step T0 can be used. Specifically, the ratio kd (kd = ΔDs / Ds) of the solid density deviation ΔDs (ΔDsk, ΔDsc, ΔDsm, ΔDsy) with respect to the reference density Ds (Dsk, Dsc, Dsm, Dsy) is obtained, and the ratio to the image area ratio A is calculated. The key opening K for obtaining the reference concentration is obtained using an API function, and a key opening deviation amount ΔK (ΔK = kd × K) for making the solid concentration deviation ΔDs zero is obtained as a product of these.

  In step T80, the ink density control convergence determination means 41 compares the key opening degree deviation amount ΔK with a predetermined value M set in advance. That is, the state where the key opening deviation amount ΔK is not so large can be determined as the state where the ink density control has converged. Here, when the key opening deviation amount ΔK is smaller than the predetermined amount M, step T130 is performed. As a result, an ink density convergence determination signal is input to the zero point calculation / setting means 33.

The determination of ink density control convergence in step T80 may be made only in one control cycle. For example, the average absolute value of the key opening deviation amount ΔK in a plurality of control cycles is compared with a predetermined amount. You may go. In this way, more accurate convergence determination can be performed.
If it is determined in step T80 that the ink density has not converged, the online control unit 46 prints the key opening deviation amounts ΔKk, ΔKc, ΔKm, ΔKy calculated by the color conversion unit 44 in step T90. Correction is performed in consideration of the dead time from the units 2a, 2b, 2c and 2d to the line sensor type IRGB densitometer 1, the reaction time of the ink key 7 per hour, and the printing speed. This correction is detected by the IRGB densitometer 1 as a change in the amount of reflected light because the ink key 7 moves after the key opening signal is input, the key opening is changed, and the amount of ink supplied to the printing sheet 8 changes. It takes into account the time delay until As such an online feedback control system with a large dead time, for example, PI control with dead time compensation, fuzzy control, robust control and the like are optimal. The online control unit 46 is for online control in which the current key opening Kk0, Kc0, Km0, Ky0 is added to the corrected key opening deviation (online control key opening deviation) ΔKk, ΔKc, ΔKm, ΔKy. The key opening degrees Kk1, Kc1, Km1, and Ky1 are input to the key opening limiter calculation unit 47.

  In step T100, the key opening limiter calculation unit 47 performs correction for restricting the upper limit value for the online control key openings Kk1, Kc1, Km1, and Ky1 calculated by the online control unit 46. This is a process for restricting an abnormal increase in the key opening due to an estimation error of the color conversion algorithm (the processes of steps T40, T50, and T60) particularly in the low image area. Then, in step T110, the key opening limiter calculating unit 47 transmits the key opening Kk, Kc, Km, Ky whose upper limit value is restricted to the printing control means 40 as a key opening signal.

In step T120, the printing control means 31 determines the opening degree of each ink key 7 of each printing unit 2a, 2b, 2c, 2d based on the key opening degree signals Kk, Kc, Km, Ky transmitted from the ink density control means 40. Adjust. As a result, the ink supply amount of each ink color is controlled to match the target color tone for each key zone.
In step S140, when the print end signal is not input due to the operator's operation or the like (when printing is continued), the above-described processing is repeated, and when the print end signal is input, the control is ended.

Since the ink key 0 point setting method of the printing press according to the second embodiment of the present invention has the above-described configuration, it is necessary for the operator to manually set the ink key 0 point when setting the ink key 0 point. Thus, the operator's workload can be reduced.
Ink key corresponding to 0 point of the ink key with high accuracy based on the ink key opening detected by the potentiometer 54 at the time when the feedback control in the automatic ink density control is converged after actually printing two patterns with different line ratios. In addition to being able to estimate and calculate the opening, there is no need to actually perform a printing operation after opening the ink key 7 by a predetermined opening S every cycle as compared with the first embodiment. The time required for setting the zero point can be shortened.

  As a result, when the ink key opening is automatically preset using the API function or the like as in the first embodiment on the basis of the line drawing rate of the printed pattern before printing, this is caused by the deviation of the ink key 0 point. The error can be reduced, and the color tone of the print sheet can be quickly changed to a desired color tone at the time of printing, thereby reducing the occurrence of damaged paper.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
In the present embodiment, the test pattern (first and second patterns) for setting the zero point is not printed, and the zero point setting is performed based on the result of actual normal printing of the product. This is different from the second embodiment, and the configuration of the other printing press is the same as that of the second embodiment. Therefore, description of parts common to the second embodiment is omitted, and parts common to the second embodiment are described using the same reference numerals.

  In the present embodiment, the ink density control as described above is performed on the basis of the image drawing rate data Ak, Ac, Am, and Ay of the product to be printed, and the ink density control convergence judgment signal is sent from the ink density control convergence judgment means 41. Is input to the zero point calculation / setting means 33, the zero point calculation / setting means 33 displays the opening degree Y'1 of each ink key (or the ink key to be set for the zero point) at that time and the image of the key zone. The linearity data X′1 is stored. Each time a different product is printed, the zero point calculation / setting unit 33 accumulates information on the ink key opening and the line ratio at the time when the ink density control is converged.

When the information of the predetermined number (here, 10) of ink key openings and the corresponding image line rate data is accumulated, the zero point calculation / setting means 33 stores zero points based on these information. Perform the operation.
FIG. 15 plots the ink key opening Y ′ accumulated in the zero-point calculation / setting means 33 and the corresponding line drawing ratio X ′, where the printing pattern is drawn on the X axis and the ink key opening is on the Y axis. It is a graph. As shown in FIG. 15, the zero point calculation in the present embodiment derives an approximate straight line from a plurality of plotted points by, for example, the least square method, and the intersection of the approximate straight line and the Y axis (that is, zero point). ) Is calculated by linear approximation. Then, based on the value calculated by the zero point calculation, the zero point calculation / setting means 33 performs the zero point setting.

  Since the 0-point setting method of the ink key according to the third embodiment of the present invention is configured as described above, it is not necessary to print a test pattern specially when setting the 0-point, and the 0-point setting is performed. This work load can be greatly reduced, and the zero point setting is performed using product printing, so that it is possible to prevent a problem that the product printing schedule is delayed due to the zero point setting.

Further, when the printing is actually performed and the feedback control in the ink density automatic control is converged, the ink key opening corresponding to the 0 key of the ink key can be estimated and calculated with high accuracy based on the ink key opening detected by the potentiometer 54. .
The zero point calculation is not limited to linear approximation, and zero point calculation may be performed by curve approximation using an approximate curve. Further, the number of ink key openings Y ′ and the corresponding drawing ratio X ′ is not limited to 10 and can be set as appropriate.

  Further, even after the accumulated number of Y ′ and X ′ reaches a predetermined number, it is possible to obtain further Y ′ and X ′ data by printing different products. In other words, so-called learning correction may be performed in which the 0 point of the ink key is updated by the above-described method. Thereby, the 0-point setting accuracy of the ink key can be further improved.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the first embodiment described above, a predetermined number of printings are performed while increasing the ink key opening stepwise from the state where the ink base roller 6 and the ink key 7 are in contact with each other, and the ink is printed on the printing sheet. In the first embodiment, first, the ink key opening (ink supply state) is set to a sufficiently large value so that the ink can be transferred to the printing sheet 8, and thereafter Alternatively, a predetermined pattern may be printed while decreasing the ink key opening stepwise, and the ink key 0 point may be set based on the ink key opening when ink transfer is no longer seen on the print sheet. .

  At this time, the ink key opening at the end point of the transfer of the ink to the printing sheet (at the time when the ink transfer is no longer seen) when the ink key opening is decreased stepwise is the first due to the hysteresis phenomenon. As in the embodiment, the opening is smaller than the ink key opening at the starting point of the transfer of ink to the printing sheet. However, in a printing machine that automatically controls the ink key opening degree, the ink key opening degree is reduced from the state where the ink is transferred to the printing sheet and the ink supply is stopped (that is, the ink key opening degree corresponding to 0 point is set). Therefore, by setting the zero point based on the ink key opening at the end point of the ink transfer as described above, the zero point setting suitable for the actual automatic ink key control can be performed.

  Further, as in the first embodiment, the ink key opening is gradually reduced from the state where the ink transfer to the printing sheet is started, and based on the ink key opening at the time when the ink transfer is completed, The zero point may be set for both when the ink key opening is increased (when ink transfer is started) and when the ink key opening is decreased (when ink transfer is completed). In this way, each 0 point can be set quickly, and the waste of ink required for setting the 0 point at the end of ink transfer can be reduced.

  In the first embodiment, in the initial setting of the ink key opening in step S102 described above, the tip of the ink key 7 and the ink source roller 6 are in contact with each other, but the present invention is not necessarily limited thereto. For example, if it is considered from the experience of an operator or the like that ink transfer cannot occur on the printing sheet 8 even if the ink key opening is set to some extent, the ink key opening is initially set to a larger opening. Also good. By doing so, it is possible to shorten the time required for setting the ink key 0 point.

  If the hysteresis characteristic (particularly the difference between the zero point at the start of ink transfer and the zero point at the end of ink transfer) can be recognized in advance, either the start of transfer or the end of transfer If the 0 point is determined, the other can be easily estimated.

It is a flowchart which shows the control flow explaining the ink key 0 point setting method which concerns on 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view showing a schematic configuration of a printing press including an ink key 0 point setting device according to a first embodiment of the present invention. It is a typical side view showing composition of an ink supply device of a printing press concerning a 1st embodiment of the present invention. It is a typical top view which shows the structure of the ink supply apparatus of the printing press which concerns on 1st Embodiment of this invention. FIG. 3 is a functional block diagram of a control system in setting an ink key 0 point of the printing press according to the first embodiment of the present invention. It is a figure which shows the predetermined pattern which concerns on 1st Embodiment of this invention. It is a functional block diagram in the ink key 0 point setting of the printing press which concerns on 2nd Embodiment of this invention. It is a figure which shows the 1st pattern and 2nd pattern which concern on 2nd Embodiment of this invention. It is a graph for demonstrating the linear approximation of the ink key 0 point which concerns on 2nd Embodiment of this invention, makes a line drawing rate into an X-axis, and makes an ink key opening degree into a Y-axis. The first opening and the second opening corresponding to the stroke rate are plotted. It is a flowchart which shows the control flow explaining the ink key 0 point setting of the printing press which concerns on 2nd Embodiment of this invention. It is a functional block diagram of the ink density control function which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the processing flow of the ink density control which concerns on 2nd Embodiment of this invention. It is a map which matches the monochrome halftone density which concerns on 2nd Embodiment of this invention with an image line rate. It is a map which matches the solid density which concerns on 2nd Embodiment of this invention with a line drawing rate and a monochrome halftone density. It is a graph for demonstrating the linear approximation of the ink key 0 point which concerns on 3rd Embodiment of this invention, taking the line drawing rate on the X-axis and the ink key opening on the Y-axis, and the accumulated ink key opening Y ′ and corresponding It is the graph which plotted the line drawing rate X 'to do. It is a graph which shows the conventional ink supply amount function (API function).

Explanation of symbols

1 IRGB densitometer (ink sensor)
2a, 2b, 2c, 2d Printing unit 3 Blanket cylinder 4 Plate cylinder 5 Ink supply device 6 Ink source rollers 7, 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j Ink key 8 Printing sheet 9 Ink Transfer roller 10a, 10b Side plate 20 Control device 21, 31 Print control means 22, 32 Ink key control means 23, 33 0-point setting means 24 Determination means 25 Input means 40 Ink density control means 41 Ink density control convergence determination means 44 Color conversion unit 45 Ink Supply Amount Calculation Unit 46 Online Control Unit 47 Key Opening Limiter Calculation Unit 48 Database 50 Ink Key Opening Adjusting Device 51 Supporting Point Shaft 52 Adjustment Screw 53 Motor (Actuator)
54 Potentiometer (Ink key opening acquisition means)
55 Push-up bracket 56 Pusher

Claims (18)

A zero point setting method for an ink key in an ink supply device of a printing press having a plurality of ink keys provided in a printing press and an opening control mechanism for controlling the opening of each ink key,
A detection step of detecting the start or end of ink transfer by controlling the opening of the ink key by the opening control mechanism of the ink key;
An ink key zero point setting method comprising: a zero point setting step of setting a zero point of the ink key opening based on a detection result of the detection step. The plurality of ink keys are disposed to face the ink base roller,
The opening degree control mechanism includes an actuator that individually drives the plurality of ink keys in a direction to be separated from and in contact with the ink base roller, and a control unit that controls the operation of the actuator.
Opening acquisition means for acquiring the mechanical opening of each of the plurality of ink keys,
The detection step includes
A first step of bringing the ink key and the ink base roller into a non-ink supply state;
After the first step, the control means operates the actuator to drive the ink key to the open side by a predetermined minute unit opening; and
After the second step, a third step of printing a predetermined number of pictures while maintaining the opening of the ink key;
A fourth step of determining whether or not the transfer of ink to the print sheet has been started from the print result during printing in the third step,
Until it is determined in the fourth step that the transfer of ink to the printing sheet has started, the second step to the fourth step are periodically repeated, and in the fourth step, the printing is performed. 2. The ink key 0 point setting method according to claim 1, wherein when it is determined that the transfer of ink to the sheet has started, the opening of the ink key one cycle before the determination is set as 0 point. The plurality of ink keys are disposed to face the ink base roller,
The opening degree control mechanism includes an actuator that individually drives the plurality of ink keys in a direction to be separated from and in contact with the ink base roller, and a control unit that controls the operation of the actuator.
Opening acquisition means for acquiring the mechanical opening of each of the plurality of ink keys,
The detection step includes
A first step of bringing the ink key into an ink supply state;
After the first step, the control means operates the actuator to drive the ink key to the closing side by a preset minute unit opening; and
After the second step, a third step of printing a predetermined number of pictures while maintaining the opening of the ink key;
A fourth step of determining whether or not the transfer of the ink to the print sheet is completed from the print result at the time of printing in the third step,
Until it is determined in the fourth step that the transfer of the ink to the printing sheet is completed, the second step to the fourth step are periodically repeated, and in the fourth step, the printing is performed. 2. The ink key zero point setting method according to claim 1, wherein when it is determined that the transfer of the ink to the sheet is completed, the opening degree of the ink key one cycle before the determination is set as zero point. An ink sensor for detecting ink on the printing sheet is provided in a travel line of the printing sheet of the printing press. In the fourth step, ink is transferred to the printing sheet based on the detection result of the ink sensor. 4. The ink key 0 point setting method according to claim 2, wherein the start or end of the ink key is determined. The opening degree obtaining means is an ink key opening degree sensor that detects the opening degree of the ink key, and the opening degree of the ink key that is set as the zero point is determined based on a detection value of the ink key opening degree sensor. The ink key zero point setting method according to any one of claims 2 to 4, wherein: The ink key 0 for a printing press according to any one of claims 2 to 5, wherein the predetermined pattern is a single-color and high-line-ratio pattern extending in the entire width direction of the printing sheet. Point setting method. 7. The ink key zero-point setting method according to claim 6, wherein the predetermined pattern is a pattern in which the above-mentioned single-color, high-line-ratio image is arranged in the print flow direction for each ink color used. .   The ink key zero point setting method according to any one of claims 1 to 7, wherein a zero point setting of the ink key is simultaneously performed in a plurality of the ink keys that are not adjacent to each other. In an ink supply device of a printing press having a plurality of ink keys and an opening control mechanism for controlling the opening of each ink key,
Detecting means for detecting the start or end of ink transfer by controlling the opening of each ink key by the opening control mechanism;
An ink key zero point setting device comprising: zero point setting means for setting the zero point of the ink key opening based on the detection result of the detection means. The plurality of ink keys are disposed to face the ink base roller,
The opening degree control mechanism includes an actuator that individually drives the plurality of ink keys in a direction to be separated from and in contact with the ink base roller, and an ink key control unit that controls the operation of the actuator.
An opening degree obtaining means for obtaining a mechanical opening degree of the ink key;
An input means for inputting a 0-point setting command signal;
Upon receiving the zero point setting command signal input by the input means, the ink key and the ink source roller are brought into a non-ink supply state, the printer is operated, and the actuator is operated through the ink key control means. A stop signal, a drive command for driving the ink key to the open side by a preset minute unit opening, and a print command for printing a predetermined number of images by holding the opening of the ink key. Printing control means for controlling the printing machine so as to be periodically input until
A determination unit that determines whether or not the transfer of ink to the print sheet has been started based on a detection result of the detection unit when printing is performed under the control of the print control unit;
If it is determined by the determination means that the transfer of ink to the print sheet has started, the opening degree of the ink key one cycle before the determination is set as 0 point, and a stop signal is output to the print control means 10. The ink key 0 point setting device according to claim 9, further comprising the 0 point setting means. The plurality of ink keys are disposed to face the ink base roller,
The opening degree control mechanism includes an actuator that individually drives the plurality of ink keys in a direction to be separated from and in contact with the ink base roller, and an ink key control unit that controls the operation of the actuator.
An opening degree obtaining means for obtaining a mechanical opening degree of the ink key;
An input means for inputting a 0-point setting command signal;
When the 0 point setting command signal input by the input means is received, the ink key and the ink base roller are brought into contact with each other to operate the printing press and to operate the actuator through the ink key control means to operate the ink key. A stop signal is input as a drive command for driving the valve to the closing side by a predetermined minute unit opening, and a print command for printing a predetermined number of images while maintaining the opening of the ink key. Printing control means for controlling the printing machine so as to be periodic,
A determination unit for determining whether or not the transfer of ink to the print sheet is completed based on a detection result of the detection unit during printing by the control of the print control unit;
When the determination means determines that the transfer of the ink to the print sheet is completed, the opening degree of the ink key one cycle before the determination is set as 0 point, and a stop signal is output to the print control means 10. The ink key 0 point setting device according to claim 9, further comprising the 0 point setting means. An ink sensor that detects ink on the printing sheet is provided in a travel line of the printing sheet, and the determination unit determines the start or end of transfer of ink to the printing sheet based on a detection result of the ink sensor. The ink key zero point setting device according to claim 10 or 11, characterized in that The opening degree acquisition means is an ink key opening degree sensor that detects the opening degree of the ink key, and the zero point setting means sets the zero point based on a detection value of the ink key opening degree sensor. The ink key 0 point setting device according to any one of claims 10 to 12. The ink key control unit according to any one of claims 10 to 13, wherein the ink key control means controls the actuator to simultaneously operate a plurality of ink keys that are not adjacent to each other. apparatus. A zero point of an ink key in an ink supply device of a printing press having a plurality of ink keys provided in the printing press and an opening control mechanism for automatically controlling a printing color tone by controlling the opening of each ink key based on a printing result A setting method,
A first step of performing printing by automatic color tone control of the opening control mechanism, and acquiring and storing a plurality of pieces of ink key opening information corresponding to the image line ratio for each key zone of each ink key;
A second step of setting an ink key opening corresponding to a case where the line drawing rate is 0 by linear approximation based on the value of the ink key opening and the line drawing rate stored in the first step to an ink key 0 point; An ink key 0 point setting method, characterized by comprising: The plurality of ink keys are disposed to face the ink base roller,
The opening degree control mechanism includes an actuator that individually drives the ink key in a direction to be in contact with and away from the ink base roller, an opening degree obtaining unit that obtains a mechanical opening degree of the ink key, and printed printing. An IRGB densitometer that detects the color density of the sheet and an opening degree of the ink key by controlling the operation of the actuator so that a printed pattern has a target line drawing rate based on the measurement result of the IRGB densitometer. Control means for controlling and automatically controlling the print color tone,
In the first step, when a first picture having only the ink color of the ink key to be adjusted among the ink keys and a first image rate is printed, and automatic color tone control by the control means has converged The value of the ink key opening at the first ink key opening is stored as the first ink key opening together with the first image drawing rate, and a second image which is a single color only of the ink color of the ink key to be adjusted and is different from the first image drawing rate. Printing a second pattern which is a linear rate, and storing the value of the ink key opening at the time when the automatic color tone control by the control means has converged as the second ink key opening together with the second image linear rate;
In the second step, a straight line is generated based on the first ink key opening degree and the first image line rate and the second ink key opening degree and the second image line rate stored in the first step. The ink key 0 point setting method according to claim 15, wherein an ink key opening corresponding to a case where the line drawing ratio is 0 is set to 0 ink key by approximation or curve approximation. The plurality of ink keys are disposed to face the ink base roller,
The opening degree control mechanism includes an actuator that individually drives the ink key in a direction to be in contact with and away from the ink base roller, an opening degree obtaining unit that obtains a mechanical opening degree of the ink key, and printed printing. An IRGB densitometer that detects the color density of the sheet and an opening degree of the ink key by controlling the operation of the actuator so that a printed pattern has a target line drawing rate based on the measurement result of the IRGB densitometer. Control means for controlling and automatically controlling the print color tone,
In the first step, each time actual product printing is performed, a plurality of image areas are obtained for each key zone by obtaining an image line ratio and an ink key opening corresponding to the image area ratio. While acquiring and storing the stroke rate and the ink key opening corresponding to each stroke rate,
In the second step, the ink key opening corresponding to the case where the image line rate is 0 is set to the ink key 0 point by linear approximation based on the plurality of sets of the ink key opening and the image line rate stored in the first step. The second step of setting the ink key opening corresponding to the case where the line drawing rate is 0 by linear approximation based on the value of the ink key opening and the line drawing rate stored in the first step as the ink key 0 point. The second step corresponds to a case where the line rate is 0 by linear approximation or curve approximation based on the ink key opening value and the line rate stored in the first step. The ink key 0 point setting method according to claim 15, wherein the ink key opening is set to an ink key 0 point. A plurality of ink keys arranged to face the ink base roller, actuators that individually drive the ink keys in the direction to be in contact with the ink base roller, and an opening for acquiring the mechanical opening of the ink key. The IRGB densitometer for detecting the color density of the printed printing sheet, and the operation of the actuator so that the pattern to be printed based on the measurement result of the IRGB densitometer has a target line rate. Ink supply device of a printing press with an automatic color tone control function, which is equipped with a control means for automatically controlling the color tone of printing by controlling the opening degree of the ink key and controlling the opening of the ink key, and actually transferring the ink to the printing sheet An ink key 0 point setting device for a printing press that sets an ink key opening at a possible boundary point as 0 point,
A first printing plate for printing a first pattern of only the ink color of the ink key to be adjusted among the ink keys and the first image rate,
A second printing plate for printing a second pattern which is a single color of only the ink color of the ink key to be adjusted and has a second image rate different from the first image rate;
A picture by the first printing plate is printed, and the value of the ink key opening at the time when the automatic color tone control by the control means has converged is stored as the first ink key opening together with the first image ratio, and the first Storage means for printing an image of the printing plate of No. 2 and storing the value of the ink key opening when the automatic color tone control by the control means converges as the second ink key opening together with the second image ratio;
Based on the first ink key opening and the first image line rate and the second ink key opening and the second image line rate stored in the storage unit, the line is drawn by linear approximation or curve approximation. An ink key zero point setting device for a printing press, comprising: a zero point setting means for setting an ink key opening degree corresponding to a rate of zero to an ink key zero point.

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